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	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2422:_Vaccine_Ordering&amp;diff=206088</id>
		<title>2422: Vaccine Ordering</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2422:_Vaccine_Ordering&amp;diff=206088"/>
				<updated>2021-02-09T13:21:35Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2422&lt;br /&gt;
| date      = February 8, 2021&lt;br /&gt;
| title     = Vaccine Ordering&lt;br /&gt;
| image     = Vaccine_ordering_-_high-resolution.png&lt;br /&gt;
| titletext = You know what they say: mRNA-1273 before tozinameran, you'll have to slay a banshee in a catamaran.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by the RULER OF SMYRNA. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This is another in the series of comics inspired by the {{w|COVID-19 pandemic}}. Two COVID-19 vaccines have been approved in the United States (from {{w|Moderna}} and a joint venture between {{w|Pfizer}} and {{w|BioNTech}}) and many people are getting vaccinated with one of the vaccines. Each of these vaccines require 2 doses, taken 3-4 weeks apart.&lt;br /&gt;
 &lt;br /&gt;
Megan is reading an article on her phone to Cueball. A report from the {{w|Centers for Disease Control and Prevention|CDC}} says that it's possible to get effective immunity against {{w|COVID-19}} when mixing {{w|RNA vaccine|mRNA vaccine doses}} from Pfizer and Moderna, but that this practice should not be the norm. The report in question can be viewed [https://www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html here]; it stresses that mixing the vaccines is acceptable only in exceptional circumstances, such as &amp;quot;when the first-dose vaccine product cannot be determined.&amp;quot;&lt;br /&gt;
&lt;br /&gt;
Cueball wonders whether the order in which you receive the vaccines matters. Megan then attempts to create {{w|Mnemonic|mnemonic devices}} to help them remember which mix-and-match strategy is best for the mRNA vaccines (e.g., &amp;quot;Beer before wine and you'll feel fine; wine before beer and you'll feel queer&amp;quot;). Megan succeeds by rhyming &amp;quot;Pfizer&amp;quot; and &amp;quot;wiser&amp;quot;, but struggles with finding a rhyme for &amp;quot;Moderna&amp;quot;, settling for {{w|Smyrna}}, an ancient city located in what is now {{w|Izmir}}, Turkey.&lt;br /&gt;
&lt;br /&gt;
A {{w|side effect}} of a drug is an effect incidental to the intended purpose of the drug. Side effects can be positive or negative, though in vaccine trials the greater concern is usually about negative side effects. Becoming ruler of an ancient city that is now only a historical ruin would certainly be an odd side effect.{{Citation needed}}&lt;br /&gt;
&lt;br /&gt;
The title text continues the theme of difficult rhymes, using the full names of both the Moderna vaccine drug ({{w|Moderna COVID-19 vaccine|mRNA-1273}}, rhymed with ''banshee'') and the Pfizer one ({{w|Pfizer–BioNTech COVID-19 vaccine|tozinameran}}, rhymed with ''catamaran'').&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[Megan and Cueball are talking. Megan is looking down and reading a news story on her phone.]&lt;br /&gt;
:Megan: The CDC says it's okay to mix and match the mRNA vaccines for doses 1 and 2, but only in &amp;quot;exceptional situations&amp;quot;.&lt;br /&gt;
:Cueball: I wonder which order works better, if either.&lt;br /&gt;
&lt;br /&gt;
:[A slimmer panel. Megan has her finger raised and her phone to her side]&lt;br /&gt;
:Megan: Well you know what they say.&lt;br /&gt;
:Megan: Moderna before Pfizer, you'll be none the wiser. &lt;br /&gt;
&lt;br /&gt;
:[A regular panel, Megan and Cueball still standing next to each other.]&lt;br /&gt;
:Megan: Pfizer before Moderna then you'll... rule ancient Smyrna.&lt;br /&gt;
:Cueball: Weird side effect.&lt;br /&gt;
:Megan: A lot of hard-to-rhyme drugs have those.&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
&lt;br /&gt;
This comic image was originally published with no {{w|Spatial anti-aliasing|anti-aliasing}}. All of its pixels were either fully black or fully white, with no shades of gray, giving the smooth lines a jagged appearance. This was fixed later in the day.&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:COVID-19]]&lt;br /&gt;
[[Category:Language]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:2421:_Tower_of_Babel&amp;diff=206045</id>
		<title>Talk:2421: Tower of Babel</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:2421:_Tower_of_Babel&amp;diff=206045"/>
				<updated>2021-02-09T02:32:25Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: Gretchen&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
&lt;br /&gt;
So is Gretchen McCulloch xkcd's resident linguist now? Is there going to be character page for her like Cory Doctorow? [[Special:Contributions/172.68.129.136|172.68.129.136]] 23:00, 5 February 2021 (UTC)&lt;br /&gt;
:I'm hoping so! We could call it &amp;quot;Gretchen McComics.&amp;quot; [[Special:Contributions/172.69.34.74|172.69.34.74]] 23:24, 5 February 2021 (UTC)&lt;br /&gt;
::That's probably not in compliance with whatever stylebook we have here but I love it. [[User:Captain Video|Captain Video]] ([[User talk:Captain Video|talk]]) 04:24, 6 February 2021 (UTC)&lt;br /&gt;
:Could it really be the same Gretchen? The time periods of the two comics are thousands of years apart. And the title text of &amp;quot;True Name of the Bear&amp;quot; says she was devoured. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 06:31, 7 February 2021 (UTC)&lt;br /&gt;
::Maybe it is meant to remind us of her from the other comic, but given the settings and no mention of her name, it cannot be determined that it is her. Great to include mention of the other comic in the explanation, but not in the transcript. Also it cannot be said that there is a real person in this comic (unless of course you think of God as a real person? But even if you consider him a person, then people may debate you on how real he is ;-) Have updated the transcript and categories. And no we should not make a category on her based on two comics, especially not when it is not clear it is her in this one. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:10, 8 February 2021 (UTC)&lt;br /&gt;
:If there's a third comic with a linguist drawn like that, I'd suggest calling the character &amp;quot;Gretchen&amp;quot; as a convenient handle regardless of whether it is or isn't Gretchen McCulloch. --[[User:Pi one|Pi one]] ([[User talk:Pi one|talk]]) 02:32, 9 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
Wait, how could a linguist exist before there were languages to study and compare? Is this the omphalos hypothesis popping up again? [[User:GreatWyrmGold|GreatWyrmGold]] ([[User talk:GreatWyrmGold|talk]]) 02:36, 6 February 2021 (UTC)&lt;br /&gt;
:They have one language. Presumably, she attempts to thoroughly study that one. This would technically make her a grammarian, but since they don't have contact with any other language, this proto-language wouldn't need make any distinction between grammarians and linguists, so &amp;quot;linguist&amp;quot; would be an appropriate translation. --[[Special:Contributions/162.158.79.49|162.158.79.49]] 05:55, 6 February 2021 (UTC)&lt;br /&gt;
::I think it is worth mentioning the paradox in the explanation. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 09:10, 8 February 2021 (UTC)&lt;br /&gt;
:There's also the possibility that the word &amp;quot;linguist&amp;quot; didn't exist before that moment. &amp;quot;What the hell's a linguist?&amp;quot; &amp;quot;Who is hells?&amp;quot;&lt;br /&gt;
:Very astute observation - I take it you are a cunning linguist? [[Special:Contributions/141.101.104.35|141.101.104.35]] 20:51, 8 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
Defining &amp;quot;colorless green ideas sleep furiously&amp;quot; {&lt;br /&gt;
    &amp;quot;colorless green ideas&amp;quot; existing is 0 .&lt;br /&gt;
    List of all existing &amp;quot;colorless green ideas&amp;quot;  that don't &amp;quot;dream furiously&amp;quot; contains 0 elements.&lt;br /&gt;
    True.&lt;br /&gt;
} [[Special:Contributions/141.101.77.60|141.101.77.60]] 06:24, 6 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
Defining &amp;quot;more people have been to Russia than I have&amp;quot; {&lt;br /&gt;
    if(Have &amp;quot;I&amp;quot; ever been to Russia?){&lt;br /&gt;
        &amp;quot;More than 1 people have been to Russia.&amp;quot;.&lt;br /&gt;
    } else {&lt;br /&gt;
        &amp;quot;More than 0 people have been to Russia.&amp;quot;.&lt;br /&gt;
    }&lt;br /&gt;
}, so something like {&lt;br /&gt;
    &amp;quot;At least 1 person that is not me has been to Russia.&amp;quot;.&lt;br /&gt;
}. [[Special:Contributions/141.101.77.60|141.101.77.60]] 06:24, 6 February 2021 (UTC)&lt;br /&gt;
:&amp;quot;I possess a number of people as chattel&amp;quot;, i.e. servants and/or slaves. (That number could be zero?) &amp;quot;The number of people who have gone to Russia exceeds this value.&amp;quot; [[Special:Contributions/141.101.77.168|141.101.77.168]] 10:29, 6 February 2021 (UTC)&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2421:_Tower_of_Babel&amp;diff=205889</id>
		<title>2421: Tower of Babel</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2421:_Tower_of_Babel&amp;diff=205889"/>
				<updated>2021-02-06T00:05:22Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: possible alternative modifier?&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2421&lt;br /&gt;
| date      = February 5, 2021&lt;br /&gt;
| title     = Tower of Babel&lt;br /&gt;
| image     = tower_of_babel.png&lt;br /&gt;
| titletext = Soon, linguists will be wandering around everywhere, saying things like &amp;quot;colorless green ideas sleep furiously&amp;quot; and &amp;quot;more people have been to Russia than I have,&amp;quot; and speech will become unintelligible.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a COLORLESS GREEN IDEA. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
The story of the {{w|Tower of Babel}} is the Biblical explanation for the existence of different languages in the world. In the story, humans endeavor to build a tower reaching heaven. Their arrogance angers God and prompts him to sabotage the project. He does this by &amp;quot;confounding their speech&amp;quot; (commonly interpreted as giving everyone their own language) inhibiting their ability to work together.&lt;br /&gt;
&lt;br /&gt;
In this retelling, however, the tower is actually finished. God is happy to receive the human visitors, and offers them a reward.&lt;br /&gt;
&lt;br /&gt;
The party that ascends to the top of the tower consists of Cueball, Megan and a third figure who might be linguist {{w|Gretchen McCulloch}}, previously seen in [[2381: The True Name of the Bear]]. When Gretchen expresses her love of words, God offers to create a panoply of languages. Megan immediately sees the problems with this, but Gretchen is enthusiastic. Instead of a punishment by God, linguistic diversity is presented as a well-intended challenge.&lt;br /&gt;
&lt;br /&gt;
{{w|Phonology}}, a part of linguistics, is the study of the sound system used in a language or dialect, or of the systems that languages use to organize sounds. {{w|b:Conlang/Advanced/Grammar/Alignment|Morphosyntactic alignment}} is the grammatical relationship between the noun arguments to a verb &amp;amp;mdash; for example, between the two arguments (in English, the subject and object) of transitive verbs like ''the dog chased the cat'', and the single argument of intransitive verbs like ''the cat ran away''.&lt;br /&gt;
&lt;br /&gt;
The title text presents two meaningless English-language phrases that illustrate the language's ability to convey confusing or paradoxical information. &amp;quot;{{w|Colorless green ideas sleep furiously}}&amp;quot;, coined by linguist {{w|Noam Chomsky}} in 1957, is an example of a sentence that is structurally correct but contains paradoxes and meaningless comparisons: something cannot be both colorless AND green (see {{w|Invisible Pink Unicorn}}), ideas do not sleep, and sleeping is not generally done furiously. That said, the sentence &amp;quot;colorless green ideas sleep furiously&amp;quot; is so well known in linguistics that a competition to make the sentence meaningful was held in 1985 and {{w|Colorless_green_ideas_sleep_furiously#Attempts_at_meaningful_interpretations|attracted a number of entrants}}. &amp;quot;More people have been to Russia than I have&amp;quot; is a well-known example of {{w|comparative illusion}}. It sounds like it means something but, upon actual analysis, does not.&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
In [[2381: The True Name of the Bear]], sentences spoken by Gretchen McCulloch do not have periods at their ends, a fact which she mentioned on Twitter. However, in this comic, she uses periods, so her previous periodlessness might be a coincidence and not a trait of her character on xkcd.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:(Cueball, Gretchen McCulloch and Megan are standing at the base of the Tower of Babel) &lt;br /&gt;
:Cueball: The Tower of Babel is complete!&lt;br /&gt;
:Megan: Let's go meet God!&lt;br /&gt;
:(Cueball, Gretchen McCulloch and Megan are now standing at the top of the Tower of Babel)&lt;br /&gt;
:Cueball: Hi God!&lt;br /&gt;
:God:  Wow, nice tower!&lt;br /&gt;
:God:  You did a great job! I'm so proud!&lt;br /&gt;
:Megan:  Thanks!&lt;br /&gt;
:God:  I'm going to give you a reward.&lt;br /&gt;
:God: What do you like about the world?&lt;br /&gt;
:Gretchen McCulloch:  Hmm. Words are really cool&lt;br /&gt;
:Megan:  No, wait-&lt;br /&gt;
:God:  Great! I'm going to give you lots of languages to study, each with its own phonology, word ordering, morphosyntactic alignment...&lt;br /&gt;
:Gretchen McCulloch: YESSSSSS!&lt;br /&gt;
:Megan:  We should not have brought a linguist.&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2421:_Tower_of_Babel&amp;diff=205888</id>
		<title>2421: Tower of Babel</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2421:_Tower_of_Babel&amp;diff=205888"/>
				<updated>2021-02-06T00:03:52Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */ just a suggestion&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2421&lt;br /&gt;
| date      = February 5, 2021&lt;br /&gt;
| title     = Tower of Babel&lt;br /&gt;
| image     = tower_of_babel.png&lt;br /&gt;
| titletext = Soon, linguists will be wandering around everywhere, saying things like &amp;quot;colorless green ideas sleep furiously&amp;quot; and &amp;quot;more people have been to Russia than I have,&amp;quot; and speech will become unintelligible.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a COLORLESS GREEN IDEA. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
The story of the {{w|Tower of Babel}} is the Biblical explanation for the existence of different languages in the world. In the story, humans endeavor to build a tower reaching heaven. Their arrogance angers God and prompts him to sabotage the project. He does this by &amp;quot;confounding their speech&amp;quot; (commonly interpreted as giving everyone their own language) inhibiting their ability to work together.&lt;br /&gt;
&lt;br /&gt;
In this retelling, however, the tower is actually finished. God is happy to receive the human visitors, and offers them a reward.&lt;br /&gt;
&lt;br /&gt;
The party that ascends to the top of the tower consists of Cueball, Megan and a third figure who might be linguist {{w|Gretchen McCulloch}}, previously seen in [[2381: The True Name of the Bear]]. When Gretchen expresses her love of words, God offers to create a panoply of languages. Megan immediately sees the problems with this, but Gretchen is enthusiastic. Instead of a punishment by God, linguistic diversity is presented as a satisfying challenge.&lt;br /&gt;
&lt;br /&gt;
{{w|Phonology}}, a part of linguistics, is the study of the sound system used in a language or dialect, or of the systems that languages use to organize sounds. {{w|b:Conlang/Advanced/Grammar/Alignment|Morphosyntactic alignment}} is the grammatical relationship between the noun arguments to a verb &amp;amp;mdash; for example, between the two arguments (in English, the subject and object) of transitive verbs like ''the dog chased the cat'', and the single argument of intransitive verbs like ''the cat ran away''.&lt;br /&gt;
&lt;br /&gt;
The title text presents two meaningless English-language phrases that illustrate the language's ability to convey confusing or paradoxical information. &amp;quot;{{w|Colorless green ideas sleep furiously}}&amp;quot;, coined by linguist {{w|Noam Chomsky}} in 1957, is an example of a sentence that is structurally correct but contains paradoxes and meaningless comparisons: something cannot be both colorless AND green (see {{w|Invisible Pink Unicorn}}), ideas do not sleep, and sleeping is not generally done furiously. That said, the sentence &amp;quot;colorless green ideas sleep furiously&amp;quot; is so well known in linguistics that a competition to make the sentence meaningful was held in 1985 and {{w|Colorless_green_ideas_sleep_furiously#Attempts_at_meaningful_interpretations|attracted a number of entrants}}. &amp;quot;More people have been to Russia than I have&amp;quot; is a well-known example of {{w|comparative illusion}}. It sounds like it means something but, upon actual analysis, does not.&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
In [[2381: The True Name of the Bear]], sentences spoken by Gretchen McCulloch do not have periods at their ends, a fact which she mentioned on Twitter. However, in this comic, she uses periods, so her previous periodlessness might be a coincidence and not a trait of her character on xkcd.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:(Cueball, Gretchen McCulloch and Megan are standing at the base of the Tower of Babel) &lt;br /&gt;
:Cueball: The Tower of Babel is complete!&lt;br /&gt;
:Megan: Let's go meet God!&lt;br /&gt;
:(Cueball, Gretchen McCulloch and Megan are now standing at the top of the Tower of Babel)&lt;br /&gt;
:Cueball: Hi God!&lt;br /&gt;
:God:  Wow, nice tower!&lt;br /&gt;
:God:  You did a great job! I'm so proud!&lt;br /&gt;
:Megan:  Thanks!&lt;br /&gt;
:God:  I'm going to give you a reward.&lt;br /&gt;
:God: What do you like about the world?&lt;br /&gt;
:Gretchen McCulloch:  Hmm. Words are really cool&lt;br /&gt;
:Megan:  No, wait-&lt;br /&gt;
:God:  Great! I'm going to give you lots of languages to study, each with its own phonology, word ordering, morphosyntactic alignment...&lt;br /&gt;
:Gretchen McCulloch: YESSSSSS!&lt;br /&gt;
:Megan:  We should not have brought a linguist.&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2421:_Tower_of_Babel&amp;diff=205886</id>
		<title>2421: Tower of Babel</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2421:_Tower_of_Babel&amp;diff=205886"/>
				<updated>2021-02-05T23:59:23Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2421&lt;br /&gt;
| date      = February 5, 2021&lt;br /&gt;
| title     = Tower of Babel&lt;br /&gt;
| image     = tower_of_babel.png&lt;br /&gt;
| titletext = Soon, linguists will be wandering around everywhere, saying things like &amp;quot;colorless green ideas sleep furiously&amp;quot; and &amp;quot;more people have been to Russia than I have,&amp;quot; and speech will become unintelligible.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a COLORLESS GREEN IDEA. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
The story of the {{w|Tower of Babel}} is the Biblical explanation for the existence of different languages in the world. In the story, humans endeavor to build a tower reaching heaven. Their arrogance angers God and prompts him to sabotage the project. He does this by &amp;quot;confounding their speech&amp;quot; (commonly interpreted as giving everyone their own language) inhibiting their ability to work together.&lt;br /&gt;
&lt;br /&gt;
In this retelling, however, the tower is actually finished. God is happy to receive the human visitors, and offers them a reward.&lt;br /&gt;
&lt;br /&gt;
The party that ascends to the top of the tower consists of Cueball, Megan and a third figure who might be linguist {{w|Gretchen McCulloch}}, previously seen in [[2381: The True Name of the Bear]]. When Gretchen expresses her love of words, God offers to create a panoply of languages. Megan immediately sees the problems with this, but Gretchen is enthusiastic. In the original story of the Tower of Babel, the different human languages are framed as a punishment by God for working together to build the tower; here, they're presented as a satisfying additional challenge.&lt;br /&gt;
&lt;br /&gt;
{{w|Phonology}}, a part of linguistics, is the study of the sound system used in a language or dialect, or of the systems that languages use to organize sounds. {{w|Morphosyntactic alignment}} is the grammatical relationship between the noun arguments to a verb &amp;amp;mdash; for example, between the two arguments (in English, the subject and object) of transitive verbs like ''the dog chased the cat'', and the single argument of intransitive verbs like ''the cat ran away''.&lt;br /&gt;
&lt;br /&gt;
The title text presents two meaningless English-language phrases that illustrate the language's ability to convey confusing or paradoxical information. &amp;quot;{{w|Colorless green ideas sleep furiously}}&amp;quot;, coined by linguist {{w|Noam Chomsky}} in 1957, is an example of a sentence that is structurally correct but contains paradoxes and meaningless comparisons: something cannot be both colorless AND green (see {{w|Invisible Pink Unicorn}}), ideas do not sleep, and sleeping is not generally done furiously. That said, the sentence &amp;quot;colorless green ideas sleep furiously&amp;quot; is so well known in linguistics that a competition to make the sentence meaningful was held in 1985 and {{w|Colorless_green_ideas_sleep_furiously#Attempts_at_meaningful_interpretations|attracted a number of entrants}}. &amp;quot;More people have been to Russia than I have&amp;quot; is a well-known example of {{w|comparative illusion}}. It sounds like it means something but, upon actual analysis, does not.&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
In [[2381: The True Name of the Bear]], sentences spoken by Gretchen McCulloch do not have periods at their ends, a fact which she mentioned on Twitter. However, in this comic, she uses periods, so her previous periodlessness might be a coincidence and not a trait of her character on xkcd.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:(Cueball, Gretchen McCulloch and Megan are standing at the base of the Tower of Babel) &lt;br /&gt;
:Cueball: The Tower of Babel is complete!&lt;br /&gt;
:Megan: Let's go meet God!&lt;br /&gt;
:(Cueball, Gretchen McCulloch and Megan are now standing at the top of the Tower of Babel)&lt;br /&gt;
:Cueball: Hi God!&lt;br /&gt;
:God:  Wow, nice tower!&lt;br /&gt;
:God:  You did a great job! I'm so proud!&lt;br /&gt;
:Megan:  Thanks!&lt;br /&gt;
:God:  I'm going to give you a reward.&lt;br /&gt;
:God: What do you like about the world?&lt;br /&gt;
:Gretchen McCulloch:  Hmm. Words are really cool&lt;br /&gt;
:Megan:  No, wait-&lt;br /&gt;
:God:  Great! I'm going to give you lots of languages to study, each with its own phonology, word ordering, morphosyntactic alignment...&lt;br /&gt;
:Gretchen McCulloch: YESSSSSS!&lt;br /&gt;
:Megan:  We should not have brought a linguist.&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2421:_Tower_of_Babel&amp;diff=205885</id>
		<title>2421: Tower of Babel</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2421:_Tower_of_Babel&amp;diff=205885"/>
				<updated>2021-02-05T23:57:48Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2421&lt;br /&gt;
| date      = February 5, 2021&lt;br /&gt;
| title     = Tower of Babel&lt;br /&gt;
| image     = tower_of_babel.png&lt;br /&gt;
| titletext = Soon, linguists will be wandering around everywhere, saying things like &amp;quot;colorless green ideas sleep furiously&amp;quot; and &amp;quot;more people have been to Russia than I have,&amp;quot; and speech will become unintelligible.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a COLORLESS GREEN IDEA. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
The story of the {{w|Tower of Babel}} is the Biblical explanation for the existence of different languages in the world. In the story, humans endeavor to build a tower reaching heaven. Their arrogance angers God and prompts him to sabotage the project. He does this by &amp;quot;confounding their speech&amp;quot; (commonly interpreted as giving everyone their own language) inhibiting their ability to work together.&lt;br /&gt;
&lt;br /&gt;
In this retelling, however, the tower is actually finished. God is happy to receive the human visitors, and offers them a reward.&lt;br /&gt;
&lt;br /&gt;
The party that ascends to the top of the tower consists of Cueball, Megan and a third figure who might be linguist {{w|Gretchen McCulloch}}, previously seen in [[2381: The True Name of the Bear]]. When Gretchen expresses her love of words, God offers to create a panoply of languages. Megan immediately sees the problems with this, but Gretchen is enthusiastic. In the original story of the Tower of Babel, the different human languages are framed as a punishment by God for working together to build the tower; here, they're presented as a satisfying additional challenge.&lt;br /&gt;
&lt;br /&gt;
{{w|Phonology}}, a part of linguistics, is the study of the sound system used in a language or dialect, or of the systems that languages use to organize sounds. {{w|Morphosyntactic alignment}} is (per Wikipedia) the grammatical relationship between arguments &amp;amp;mdash; for example, between the two arguments (in English, subject and object) of transitive verbs like ''the dog chased the cat'', and the single argument of intransitive verbs like ''the cat ran away''.&lt;br /&gt;
&lt;br /&gt;
The title text presents two meaningless English-language phrases that illustrate the language's ability to convey confusing or paradoxical information. &amp;quot;{{w|Colorless green ideas sleep furiously}}&amp;quot;, coined by linguist {{w|Noam Chomsky}} in 1957, is an example of a sentence that is structurally correct but contains paradoxes and meaningless comparisons: something cannot be both colorless AND green (see {{w|Invisible Pink Unicorn}}), ideas do not sleep, and sleeping is not generally done furiously. That said, the sentence &amp;quot;colorless green ideas sleep furiously&amp;quot; is so well known in linguistics that a competition to make the sentence meaningful was held in 1985 and {{w|Colorless_green_ideas_sleep_furiously#Attempts_at_meaningful_interpretations|attracted a number of entrants}}. &amp;quot;More people have been to Russia than I have&amp;quot; is a well-known example of {{w|comparative illusion}}. It sounds like it means something but, upon actual analysis, does not.&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
In [[2381: The True Name of the Bear]], sentences spoken by Gretchen McCulloch do not have periods at their ends, a fact which she mentioned on Twitter. However, in this comic, she uses periods, so her previous periodlessness might be a coincidence and not a trait of her character on xkcd.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:(Cueball, Gretchen McCulloch and Megan are standing at the base of the Tower of Babel) &lt;br /&gt;
:Cueball: The Tower of Babel is complete!&lt;br /&gt;
:Megan: Let's go meet God!&lt;br /&gt;
:(Cueball, Gretchen McCulloch and Megan are now standing at the top of the Tower of Babel)&lt;br /&gt;
:Cueball: Hi God!&lt;br /&gt;
:God:  Wow, nice tower!&lt;br /&gt;
:God:  You did a great job! I'm so proud!&lt;br /&gt;
:Megan:  Thanks!&lt;br /&gt;
:God:  I'm going to give you a reward.&lt;br /&gt;
:God: What do you like about the world?&lt;br /&gt;
:Gretchen McCulloch:  Hmm. Words are really cool&lt;br /&gt;
:Megan:  No, wait-&lt;br /&gt;
:God:  Great! I'm going to give you lots of languages to study, each with its own phonology, word ordering, morphosyntactic alignment...&lt;br /&gt;
:Gretchen McCulloch: YESSSSSS!&lt;br /&gt;
:Megan:  We should not have brought a linguist.&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2419:_Hug_Count&amp;diff=205819</id>
		<title>2419: Hug Count</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2419:_Hug_Count&amp;diff=205819"/>
				<updated>2021-02-05T03:08:45Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2419&lt;br /&gt;
| date      = February 1, 2021&lt;br /&gt;
| title     = Hug Count&lt;br /&gt;
| image     = hug_count.png&lt;br /&gt;
| titletext = I've never been that big of a hug person, but it turns out I'm not quite this small of a hug person either.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a HUGGABLE ROBOT. It would probably be good to add a bit more explanation on the pandemic. Do NOT delete this tag too soon.}}&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
The comic displays a bar chart showing the number of Individuals [[Randall]] has hugged vs the year, spanning from 1996 to 2021, and goes up to 35 individuals. While it varies a decent amount for the first 24 years, it drops sharply in 2020 and goes even lower in 2021. However, it should be noted that 2021 (at the time of the comic) had just begun, which is why the final bar is grey - the year isn't over yet and as such it is incomplete. It seems he is down to only two people hugged in 2021, one of which is most likely his wife. In 2020 he managed 5 different hugs, but the extra three may have been before the onset of corona precautions in the US.&lt;br /&gt;
&lt;br /&gt;
This is because in 2020 when the pandemic happened, everyone had to social distance and avoid contact with strangers. This was a widely used method of slowing the spread of COVID-19. People are asked to not closely associate with those outside a very limited 'bubble' or even isolating individuals in their own household. As such, people have had less physical contact with each other since the beginning of this pandemic, including hugs.&lt;br /&gt;
&lt;br /&gt;
No explanation is given for the variations year-to-year preceding 2020, and much of it may be [[2101: Technical Analysis|random walks]]. However, one can see a major spike in hug levels in 2010 and 2011; Randall's wife [[818|was diagnosed]] with cancer in late 2010 (see [[:Category:Cancer]]). Loved ones of those with cancer tend to receive much compassion from others, and compassion tends to beget hugs.&lt;br /&gt;
&lt;br /&gt;
The title text states that, while Randall isn't very big on hugs, he too desires hugs. It plays on the common phrase &amp;quot;I'm not too big of an (x) person&amp;quot;, which is used to indicate that someone isn't extremely fond of said activity. One could then infer the person is not fond of the activity at all, though in this case, he indicates his desire for hugs is non-zero, as presumably demonstrated by the frequency being now less than even he would prefer.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[A bar graph is shown with 25 black bars and one gray at the far right. Most of the bars have a height around the center of the graph, but the one in the middle is clearly higher than all others and also the two before and after are lower than average. There are also a couple of high bars in pairs on either side of the central spike. The far-right, however, are two very low bars, with the last in gray less than half the height of the previous, which was already only a third of the next lowest bar. There are numbers on both axes. The X-axis has the year for every fifth year below the relevant bar, and the number of hugs is given in intervals of 10 on the Y-axis. The Y-axis has ticks for every number, but those with labels are longer.  The chart has a title written above:]&lt;br /&gt;
:Estimated Number of Distinct People Hugged per Year&lt;br /&gt;
&lt;br /&gt;
:[Y-axis:]&lt;br /&gt;
:30 &lt;br /&gt;
:20 &lt;br /&gt;
:10&lt;br /&gt;
:0&lt;br /&gt;
&lt;br /&gt;
:[X-axis:]&lt;br /&gt;
:2000&amp;amp;nbsp;&amp;amp;nbsp;2005&amp;amp;nbsp;&amp;amp;nbsp;2010&amp;amp;nbsp;&amp;amp;nbsp;2015&amp;amp;nbsp;&amp;amp;nbsp;2020&lt;br /&gt;
&lt;br /&gt;
==Table of number of people hugged==&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
! Year !! People&lt;br /&gt;
|-&lt;br /&gt;
| 1996 || 31&lt;br /&gt;
|-&lt;br /&gt;
| 1997 || 28&lt;br /&gt;
|-&lt;br /&gt;
| 1998 || 23&lt;br /&gt;
|-&lt;br /&gt;
| 1999 || 25&lt;br /&gt;
|-&lt;br /&gt;
| 2000 || 21&lt;br /&gt;
|-&lt;br /&gt;
| 2001 || 18&lt;br /&gt;
|-&lt;br /&gt;
| 2002 || 28&lt;br /&gt;
|-&lt;br /&gt;
| 2003 || 24&lt;br /&gt;
|-&lt;br /&gt;
| 2004 || 17&lt;br /&gt;
|-&lt;br /&gt;
| 2005 || 19&lt;br /&gt;
|-&lt;br /&gt;
| 2006 || 14&lt;br /&gt;
|-&lt;br /&gt;
| 2007 || 35&lt;br /&gt;
|-&lt;br /&gt;
| 2008 || 17&lt;br /&gt;
|-&lt;br /&gt;
| 2009 || 16&lt;br /&gt;
|-&lt;br /&gt;
| 2010 || 27&lt;br /&gt;
|-&lt;br /&gt;
| 2011 || 29&lt;br /&gt;
|-&lt;br /&gt;
| 2012 || 18&lt;br /&gt;
|-&lt;br /&gt;
| 2013 || 15&lt;br /&gt;
|-&lt;br /&gt;
| 2014 || 16&lt;br /&gt;
|-&lt;br /&gt;
| 2015 || 22&lt;br /&gt;
|-&lt;br /&gt;
| 2016 || 15&lt;br /&gt;
|-&lt;br /&gt;
| 2017 || 21&lt;br /&gt;
|-&lt;br /&gt;
| 2018 || 19&lt;br /&gt;
|-&lt;br /&gt;
| 2019 || 25&lt;br /&gt;
|-&lt;br /&gt;
| 2020 || &amp;amp;nbsp; 5&lt;br /&gt;
|-&lt;br /&gt;
| 2021 || &amp;amp;nbsp; 2&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Bar charts]]&lt;br /&gt;
[[Category:COVID-19]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2419:_Hug_Count&amp;diff=205734</id>
		<title>2419: Hug Count</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2419:_Hug_Count&amp;diff=205734"/>
				<updated>2021-02-03T21:22:33Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Table of number of people hugged */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2419&lt;br /&gt;
| date      = February 1, 2021&lt;br /&gt;
| title     = Hug Count&lt;br /&gt;
| image     = hug_count.png&lt;br /&gt;
| titletext = I've never been that big of a hug person, but it turns out I'm not quite this small of a hug person either.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a HUGGABLE ROBOT. It would probably be good to add a bit more explanation on the pandemic. Do NOT delete this tag too soon.}}&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
The comic displays a bar chart showing the number of Individuals [[Randall]] has hugged vs the year, spanning from 1996 to 2021, and goes up to 35 individuals. While it varies a decent amount for the first 24 years, it drops sharply in 2020, and goes even lower in 2021. However, it should be noted that 2021 (at the time of the comic) had just begun, which is why the final bar is grey - the year isn't over yet and as such it is incomplete. Seems he is down to only two person hugged in 2021, one of which is most likely his wife. In 2020 he managed 5 different hugs, but the extra three may have been before the onset of corona precautions in the US.&lt;br /&gt;
&lt;br /&gt;
This is due to the fact that in 2020, when the pandemic happened, everyone had to social distance and avoid contact with strangers. This was a widely used method of slowing the spread of COVID-19. People are asked to not closely associate with those outside a very limited 'bubble' or even isolating individuals in their own household. As such, people have had less physical contact with each other since the beginning of this pandemic, including hugs.&lt;br /&gt;
&lt;br /&gt;
No explanation is given for the variations year-to-year preceding 2020, and much of it may be [[2101: Technical Analysis|random walks]]. However, one can see a major spike in hug levels in 2010 and 2011; Randall's wife [[818|was diagnosed]] with cancer in late 2010 (see [[:Category:Cancer]]). Loved ones of those with cancer tend to receive much compassion from others, and compassion tends to beget hugs.&lt;br /&gt;
&lt;br /&gt;
The title text states that, while Randall isn't very big on hugs, he too desires hugs. It plays on the common phrase &amp;quot;I'm not too big of an (x) person&amp;quot;, which is used to indicate that someone isn't extremely fond of said activity. One could then infer the person is not fond of the activity at all, though in this case he indicates his desire for hugs, though small, is non-zero as presumably demonstrated by the frequency being now less than even he would prefer.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[A bar graph is shown with 25 black bars and one gray at the far right. Most of the bars have a height around the center of the graph, but the one in the middle is clearly higher than all others and also the two before and after are lower than average. There are also a couple of high bars in pairs on either side of the central spike. The the far right, however, are two very low bars, with the last in gray less than half the height of the previous, which was already only a third of the next lowest bar. There are numbers on both axis. The X-axis has the year for every fifth year below the relevant bar, and the number of hugs is given in intervals of 10 on the Y-axis. The Y axis has ticks for every number, but those with labels are longer.  The chart has a title written above:]&lt;br /&gt;
:Estimated Number of Distinct People Hugged per Year&lt;br /&gt;
&lt;br /&gt;
:[Y-axis:]&lt;br /&gt;
:30 &lt;br /&gt;
:20 &lt;br /&gt;
:10&lt;br /&gt;
:0&lt;br /&gt;
&lt;br /&gt;
:[X-axis:]&lt;br /&gt;
:2000&amp;amp;nbsp;&amp;amp;nbsp;2005&amp;amp;nbsp;&amp;amp;nbsp;2010&amp;amp;nbsp;&amp;amp;nbsp;2015&amp;amp;nbsp;&amp;amp;nbsp;2020&lt;br /&gt;
&lt;br /&gt;
==Table of number of people hugged==&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
! Year !! People&lt;br /&gt;
|-&lt;br /&gt;
| 1996 || 31&lt;br /&gt;
|-&lt;br /&gt;
| 1997 || 28&lt;br /&gt;
|-&lt;br /&gt;
| 1998 || 23&lt;br /&gt;
|-&lt;br /&gt;
| 1999 || 25&lt;br /&gt;
|-&lt;br /&gt;
| 2000 || 21&lt;br /&gt;
|-&lt;br /&gt;
| 2001 || 18&lt;br /&gt;
|-&lt;br /&gt;
| 2002 || 28&lt;br /&gt;
|-&lt;br /&gt;
| 2003 || 24&lt;br /&gt;
|-&lt;br /&gt;
| 2004 || 17&lt;br /&gt;
|-&lt;br /&gt;
| 2005 || 19&lt;br /&gt;
|-&lt;br /&gt;
| 2006 || 14&lt;br /&gt;
|-&lt;br /&gt;
| 2007 || 35&lt;br /&gt;
|-&lt;br /&gt;
| 2008 || 17&lt;br /&gt;
|-&lt;br /&gt;
| 2009 || 16&lt;br /&gt;
|-&lt;br /&gt;
| 2010 || 27&lt;br /&gt;
|-&lt;br /&gt;
| 2011 || 29&lt;br /&gt;
|-&lt;br /&gt;
| 2012 || 18&lt;br /&gt;
|-&lt;br /&gt;
| 2013 || 15&lt;br /&gt;
|-&lt;br /&gt;
| 2014 || 16&lt;br /&gt;
|-&lt;br /&gt;
| 2015 || 22&lt;br /&gt;
|-&lt;br /&gt;
| 2016 || 15&lt;br /&gt;
|-&lt;br /&gt;
| 2017 || 21&lt;br /&gt;
|-&lt;br /&gt;
| 2018 || 19&lt;br /&gt;
|-&lt;br /&gt;
| 2019 || 25&lt;br /&gt;
|-&lt;br /&gt;
| 2020 || &amp;amp;nbsp; 5&lt;br /&gt;
|-&lt;br /&gt;
| 2021 || &amp;amp;nbsp; 2&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Bar charts]]&lt;br /&gt;
[[Category:COVID-19]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2419:_Hug_Count&amp;diff=205730</id>
		<title>2419: Hug Count</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2419:_Hug_Count&amp;diff=205730"/>
				<updated>2021-02-03T20:44:03Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Table of number of people hugged */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2419&lt;br /&gt;
| date      = February 1, 2021&lt;br /&gt;
| title     = Hug Count&lt;br /&gt;
| image     = hug_count.png&lt;br /&gt;
| titletext = I've never been that big of a hug person, but it turns out I'm not quite this small of a hug person either.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a HUGGABLE ROBOT. It would probably be good to add a bit more explanation on the pandemic. Do NOT delete this tag too soon.}}&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
The comic displays a bar chart showing the number of Individuals [[Randall]] has hugged vs the year, spanning from 1996 to 2021, and goes up to 35 individuals. While it varies a decent amount for the first 24 years, it drops sharply in 2020, and goes even lower in 2021. However, it should be noted that 2021 (at the time of the comic) had just begun, which is why the final bar is grey - the year isn't over yet and as such it is incomplete. Seems he is down to only two person hugged in 2021, one of which is most likely his wife. In 2020 he managed 5 different hugs, but the extra three may have been before the onset of corona precautions in the US.&lt;br /&gt;
&lt;br /&gt;
This is due to the fact that in 2020, when the pandemic happened, everyone had to social distance and avoid contact with strangers. This was a widely used method of slowing the spread of COVID-19. People are asked to not closely associate with those outside a very limited 'bubble' or even isolating individuals in their own household. As such, people have had less physical contact with each other since the beginning of this pandemic, including hugs.&lt;br /&gt;
&lt;br /&gt;
No explanation is given for the variations year-to-year preceding 2020, and much of it may be [[2101: Technical Analysis|random walks]]. However, one can see a major spike in hug levels in 2010 and 2011; Randall's wife [[818|was diagnosed]] with cancer in late 2010 (see [[:Category:Cancer]]). Loved ones of those with cancer tend to receive much compassion from others, and compassion tends to beget hugs.&lt;br /&gt;
&lt;br /&gt;
The title text states that, while Randall isn't very big on hugs, he too desires hugs. It plays on the common phrase &amp;quot;I'm not too big of an (x) person&amp;quot;, which is used to indicate that someone isn't extremely fond of said activity. One could then infer the person is not fond of the activity at all, though in this case he indicates his desire for hugs, though small, is non-zero as presumably demonstrated by the frequency being now less than even he would prefer.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[A bar graph is shown with 25 black bars and one gray at the far right. Most of the bars have a height around the center of the graph, but the one in the middle is clearly higher than all others and also the two before and after are lower than average. There are also a couple of high bars in pairs on either side of the central spike. The the far right, however, are two very low bars, with the last in gray less than half the height of the previous, which was already only a third of the next lowest bar. There are numbers on both axis. The X-axis has the year for every fifth year below the relevant bar, and the number of hugs is given in intervals of 10 on the Y-axis. The Y axis has ticks for every number, but those with labels are longer.  The chart has a title written above:]&lt;br /&gt;
:Estimated Number of Distinct People Hugged per Year&lt;br /&gt;
&lt;br /&gt;
:[Y-axis:]&lt;br /&gt;
:30 &lt;br /&gt;
:20 &lt;br /&gt;
:10&lt;br /&gt;
:0&lt;br /&gt;
&lt;br /&gt;
:[X-axis:]&lt;br /&gt;
:2000&amp;amp;nbsp;&amp;amp;nbsp;2005&amp;amp;nbsp;&amp;amp;nbsp;2010&amp;amp;nbsp;&amp;amp;nbsp;2015&amp;amp;nbsp;&amp;amp;nbsp;2020&lt;br /&gt;
&lt;br /&gt;
==Table of number of people hugged==&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
! Year !! People&lt;br /&gt;
|-&lt;br /&gt;
| 1996 || 31&lt;br /&gt;
|-&lt;br /&gt;
| 1997 || 28&lt;br /&gt;
|-&lt;br /&gt;
| 1998 || 23&lt;br /&gt;
|-&lt;br /&gt;
| 1999 || 25&lt;br /&gt;
|-&lt;br /&gt;
| 2000 || 21&lt;br /&gt;
|-&lt;br /&gt;
| 2001 || 18&lt;br /&gt;
|-&lt;br /&gt;
| 2002 || 28&lt;br /&gt;
|-&lt;br /&gt;
| 2003 || 24&lt;br /&gt;
|-&lt;br /&gt;
| 2004 || 17&lt;br /&gt;
|-&lt;br /&gt;
| 2005 || 19&lt;br /&gt;
|-&lt;br /&gt;
| 2006 || 14&lt;br /&gt;
|-&lt;br /&gt;
| 2007 || 35&lt;br /&gt;
|-&lt;br /&gt;
| 2008 || 17&lt;br /&gt;
|-&lt;br /&gt;
| 2009 || 16&lt;br /&gt;
|-&lt;br /&gt;
| 2010 || 27&lt;br /&gt;
|-&lt;br /&gt;
| 2011 || 29&lt;br /&gt;
|-&lt;br /&gt;
| 2012 || 18&lt;br /&gt;
|-&lt;br /&gt;
| 2013 || 15&lt;br /&gt;
|-&lt;br /&gt;
| 2014 || 16&lt;br /&gt;
|-&lt;br /&gt;
| 2015 || 22&lt;br /&gt;
|-&lt;br /&gt;
| 2016 || 15&lt;br /&gt;
|-&lt;br /&gt;
| 2017 || 21&lt;br /&gt;
|-&lt;br /&gt;
| 2018 || 19&lt;br /&gt;
|-&lt;br /&gt;
| 2019 || 25&lt;br /&gt;
|-&lt;br /&gt;
| 2020 || 5&lt;br /&gt;
|-&lt;br /&gt;
| 2021 || 2&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Bar charts]]&lt;br /&gt;
[[Category:COVID-19]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:2419:_Hug_Count&amp;diff=205701</id>
		<title>Talk:2419: Hug Count</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:2419:_Hug_Count&amp;diff=205701"/>
				<updated>2021-02-02T19:23:02Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: c&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
I don't know how this makes me feel. I just don't hug. Maybe a couple of female relatives as I leave the traditional Christmas gathering (that didn't happen in 2020) because ''they'' expect it of me. But some societies (I'll namecheck the Italians, but there are many others) would possibly break those totals in a day (pre-Covid) just by going to the market-place and sealing deals with the local tradespeople. So my chart dipped drastically ast year, but not so much by absolute count. (No, not looking for sympathy, or virtual hugs, just saying...) [[Special:Contributions/141.101.77.126|141.101.77.126]] 23:33, 1 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
What happened in 2007? Seems like a sizeable spike. Being in a reception line at a wedding, for instance? [[Special:Contributions/173.245.54.211|173.245.54.211]] 23:43, 1 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
No citation.  Is this Randall's personal chart, do you figure?  [[User:Ekedolphin|Ekedolphin]] ([[User talk:Ekedolphin|talk]]) 00:18, 2 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
2007 was the year of the xkcd meetup, which involved a lot of hugs, some of which may have involved Randall. Randall also moved from Virginia to Massachusetts that year, which may have resulted in separate small groups of people hugged in the same year. (Both of these facts are mentioned in his blog post from that October 1st.) [[Special:Contributions/108.162.219.56|108.162.219.56]] 01:35, 2 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
The {{w|Free Hugs Campaign}} peaked between 2006 and 2007.&lt;br /&gt;
&lt;br /&gt;
2011 is the year Randall announced his gf's cancer. This might mean more people hugged him in support. 2010 might have been a time when some people close to him already knew about that (before the announcement), this would explain the big number in 2010, too. In 2015 he went on a book tour and had many signing sessions, where people might have hugged him. --[[Special:Contributions/162.158.129.59|162.158.129.59]] 03:54, 2 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
Mine is between 0-3 every year since 4th grade. Primarily my sister, my mother, and now my niece. I am nearly old enough now to go through a midlife crisis. Any other true anti-social people here just now realizing how little you get out? [[Special:Contributions/108.162.237.134|108.162.237.134]] 09:22, 2 February 2021 (UTC)&lt;br /&gt;
:I'm probably in the 10-15 range most years, but around 5 for the past year. Being mostly confined to the house really hasn't bothered me, though, so I might well qualify as anti-social... [[Special:Contributions/162.158.78.108|162.158.78.108]] 12:42, 2 February 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
Whether or not this is significantly less for some people or not, it's still sad for me. Of course, being an extrovert might have impacted that, but to me, it just represents everything, in general, that's happened. [[User:Char Latte49|Char Latte49]]&lt;br /&gt;
:It's sad about 2020, but appears to be hopeful about 2021. He already has 2 hug in the first month. If that trend continues, it should end up being an average year. And it may accelerate as more people are vaccinated. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 18:13, 2 February 2021 (UTC)&lt;br /&gt;
:: If he has a small set of people he can get hug under Covid rules, likely he'd hug them early in the year, and the number would look normal at first but then not increase much in later months.  Just saying: hope is good, yes, but the number of hugs in January doesn't really mean much. --[[User:Pi one|Pi one]] ([[User talk:Pi one|talk]]) 19:23, 2 February 2021 (UTC)&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2419:_Hug_Count&amp;diff=205696</id>
		<title>2419: Hug Count</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2419:_Hug_Count&amp;diff=205696"/>
				<updated>2021-02-02T15:40:14Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2419&lt;br /&gt;
| date      = February 1, 2021&lt;br /&gt;
| title     = Hug Count&lt;br /&gt;
| image     = hug_count.png&lt;br /&gt;
| titletext = I've never been that big of a hug person, but it turns out I'm not quite this small of a hug person either.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a HUGGABLE ROBOT. It would probably be good to add a bit more explanation on the pandemic. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
The comic strip is simply a graph showing the number of Individuals Hugged vs the Year, spanning from 1996 to 2021, and goes up to 35 individuals. While it varies a decent amount for the first 24 years, it drops sharply in 2020, and goes even lower in 2021. However, it should be noted that 2021 (at the time of the comic) had just begun, which is why the final bar is grey - the year isn't over yet and as such it is incomplete.&lt;br /&gt;
&lt;br /&gt;
This is due to the fact that in 2020, when the pandemic happened, everyone had to social distance and avoid contact with strangers. This was a widely used method of slowing the spread of COVID-19. People are asked to not closely associate with those outside a very limited 'bubble' or even isolating individuals in their own household. As such, people have had less physical contact with each other since the beginning of this pandemic, including hugs.&lt;br /&gt;
&lt;br /&gt;
No explanation is given for the variations year-to-year preceding 2020, and much of it may be [[2101: Technical Analysis|random walks]]. However, one can see a major spike in hug levels in 2010 and 2011; [[Randall]]'s wife [[818|was diagnosed]] with cancer in late 2010 (see [[:Category:Cancer]]). Loved ones of those with cancer tend to receive much compassion from others, and compassion tends to beget hugs.{{Citation needed}}&lt;br /&gt;
&lt;br /&gt;
The title text states that, while [[Randall]] isn't very big on hugs, he too desires hugs. It plays on the common phrase &amp;quot;I'm not too big of an (x) person&amp;quot;, which is used to indicate that someone isn't extremely fond of said activity. One could then infer the person is not fond of the activity at all, though in this case he indicates his desire for hugs, though small, is non-zero as presumably demonstrated by the frequency being now less than even he would prefer.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
[Title of Chart:]&lt;br /&gt;
Estimated Number of Distinct People Hugged per Year&lt;br /&gt;
&lt;br /&gt;
[Y Axis:]&lt;br /&gt;
0 to 30&lt;br /&gt;
&lt;br /&gt;
[X Axis:]&lt;br /&gt;
Years from 1996 until 2021&lt;br /&gt;
&lt;br /&gt;
{|&lt;br /&gt;
! Year !! People&lt;br /&gt;
|-&lt;br /&gt;
! 1996 || 31&lt;br /&gt;
|-&lt;br /&gt;
! 1997 || 28&lt;br /&gt;
|-&lt;br /&gt;
! 1998 || 23&lt;br /&gt;
|-&lt;br /&gt;
! 1999 || 25&lt;br /&gt;
|-&lt;br /&gt;
! 2000 || 21&lt;br /&gt;
|-&lt;br /&gt;
! 2001 || 18&lt;br /&gt;
|-&lt;br /&gt;
! 2002 || 28&lt;br /&gt;
|-&lt;br /&gt;
! 2003 || 24&lt;br /&gt;
|-&lt;br /&gt;
! 2004 || 17&lt;br /&gt;
|-&lt;br /&gt;
! 2005 || 19&lt;br /&gt;
|-&lt;br /&gt;
! 2006 || 14&lt;br /&gt;
|-&lt;br /&gt;
! 2007 || 35&lt;br /&gt;
|-&lt;br /&gt;
! 2008 || 17&lt;br /&gt;
|-&lt;br /&gt;
! 2009 || 16&lt;br /&gt;
|-&lt;br /&gt;
! 2010 || 27&lt;br /&gt;
|-&lt;br /&gt;
! 2011 || 29&lt;br /&gt;
|-&lt;br /&gt;
! 2012 || 18&lt;br /&gt;
|-&lt;br /&gt;
! 2013 || 15&lt;br /&gt;
|-&lt;br /&gt;
! 2014 || 16&lt;br /&gt;
|-&lt;br /&gt;
! 2015 || 22&lt;br /&gt;
|-&lt;br /&gt;
! 2016 || 15&lt;br /&gt;
|-&lt;br /&gt;
! 2017 || 21&lt;br /&gt;
|-&lt;br /&gt;
! 2018 || 19&lt;br /&gt;
|-&lt;br /&gt;
! 2019 || 25&lt;br /&gt;
|-&lt;br /&gt;
! 2020 || 5&lt;br /&gt;
|-&lt;br /&gt;
! 2021 || 2&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Bar charts]]&lt;br /&gt;
[[Category:COVID-19]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2418:_Metacarcinization&amp;diff=205607</id>
		<title>2418: Metacarcinization</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2418:_Metacarcinization&amp;diff=205607"/>
				<updated>2021-01-30T23:30:12Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2418&lt;br /&gt;
| date      = January 29, 2021&lt;br /&gt;
| title     = Metacarcinization&lt;br /&gt;
| image     = metacarcinization.png&lt;br /&gt;
| titletext = Scientists still don't know how marine biologists manage to so consistently bring up whalefall ecosystems, when relevant conversational openings are so few and far between.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a HEAVILY OPTIMIZED CRAB. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
The comic strip opens with a conversation between [[White Hat]] and [[Cueball]] as they are walking together.  White Hat asks Cueball if he has seen a video of a crow sledding on a roof &amp;amp;mdash; presumably [https://www.youtube.com/watch?v=6uXiAe7Oc-I this one], or one of its later viral reposts. ([https://laughingsquid.com/dog-rides-toboggan-down-hill/ Animals sledding] seems to be a thing lately). In this case, the crow is a {{w|Hooded Crow}}. Cueball remarks that it's a cool example of {{w|tool use by animals}}, a sign of intelligence (which corvids [Corvidae; the crow family], including crows, ravens, and [https://ocw.mit.edu/courses/brain-and-cognitive-sciences/9-20-animal-behavior-fall-2013/lecture-notes/MIT9_20F13_Lec4.pdf jackdaws], are famous for).  He then points out that {{w|Tool use by sea otters|sea otters use tools}} too, namely using stones to crack open crab shells.  &lt;br /&gt;
&lt;br /&gt;
This in turn leads him to bring up the fact that the 'crab' body plan has evolved multiple times, a phenomenon known as {{w|carcinization}}, previously discussed in [[2314: Carcinization]].  In that strip, Cueball turned into a crab shortly after hearing about carcinization, so perhaps White Hat will likewise be transformed momentarily. &lt;br /&gt;
&lt;br /&gt;
The caption is a joke that, much like natural life-forms have evolved into crab-like forms multiple independent times, so too do all of Cueball's (or Randall's) conversations evolve into a discussion of that evolutionary process.&lt;br /&gt;
&lt;br /&gt;
In the title text, Randall jokes that marine biologists have a similar tendency to bring up {{w|Whale fall|whalefall}} (or &amp;quot;whale fall&amp;quot;) ecosystems, which arise whenever a whale's carcass falls onto the deep ocean floor.  Such occurrences are relatively rare, perhaps occurring once every few miles on whale migration routes, but they happen anyway, much like conversations about them. Another example of scientists having a tendency to bring up facts from their field of study can be found at [[1610: Fire Ants]], and Randall often brings up the fact that birds evolved from dinosaurs.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[White Hat and Cueball are walking together.  White Hat has his smartphone out in his hand.&lt;br /&gt;
:White Hat: Have you seen this video of a crow sledding on a roof?&lt;br /&gt;
:Cueball: Yeah! It's always cool to see animals using tools.&lt;br /&gt;
:Cueball: Like how sea otters use rocks to open crab shells.&lt;br /&gt;
:Cueball: Hey, did you know the &amp;quot;crab&amp;quot; body plan has evolved multiple times?&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:Regardless of the starting topic, any conversation with me eventually converges to carcinization.&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring White Hat]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Animals]]&lt;br /&gt;
[[Category:Biology]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205600</id>
		<title>2417: 1/1,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205600"/>
				<updated>2021-01-30T14:14:41Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: Undo revision 205598 by 172.68.132.157 (talk)&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2417&lt;br /&gt;
| date      = January 27, 2021&lt;br /&gt;
| title     = 1/1,000th Scale World&lt;br /&gt;
| image     = 1_1000th_scale_world.png&lt;br /&gt;
| titletext = We're worried that a regular whale will get into a 30-foot-deep ocean trench section and filter-feed on all the tiny whales.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a STATUE OF LIBERTY MINIFIG. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is the third comic in the [[:Category:Scale World|Scale World]] series, this time with a smaller scale-factor and thus a larger world than the earlier ones. As in the previous comics, [[Randall]] has a seemingly complete copy of Earth, this time at a 1:1000 scale, with various features and warnings labeled. Again, real-world features and phenomena are replicated at scale. As before, the model is very extensive, with in this case several underground neutrino detectors/observatories being replicated.&lt;br /&gt;
&lt;br /&gt;
Several of the warnings point out humorous consequences of the scale, such as non-scaled goldfish eating scaled-down blue whales.  Other than the usual homo sapiens, introduction of non-scaled animals into the scaled world (with consistently humorous consequences) is an addition to the earlier comics of the series.&lt;br /&gt;
&lt;br /&gt;
===Table===&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
| Keep hot objects off the ice sheet over the south pole neutrino observatory&lt;br /&gt;
| Hot objects may emit Cherenkov radiation, which would result in the observatory detecting false positives of neutrino observations. They may also melt the ice that shields the detectors from other particles that would trigger false positives.&lt;br /&gt;
| The fact that people are not supposed to create false positives implies that the neutrino detector is functional.&lt;br /&gt;
|-&lt;br /&gt;
| Be patient: Niagara falls will take a few minutes to fill your water glass&lt;br /&gt;
| The flow rate is scaled down with the size. According to the [[what if]] ''{{what if|147|Niagara Straw}}, the Niagara Falls flow is regulated to 100,000 cubic feet per second on the tourist season and to 50,000 cubic feet per second offseason and at night. Once scaled to 1/1000, that flow would be 2.83 or 1.41ml per second. If a standard glass of water is 250ml, it would take about 90&amp;amp;ndash;180 seconds for the waterfall to fill it. &lt;br /&gt;
&lt;br /&gt;
However, a 1/1000th replica of scale Niagra falls would be over a meter wide, so without some kind of system to divert the whole flow into one spot, it would not be possible to fill a glass this quickly. Also, the height of the scaled-down Niagra falls would be 5cm, with another 5cm between the water level and the riverbed, so it might be difficult to fill a glass depending on its height.&lt;br /&gt;
| This item is likely to be a reference to the famous Arthur C. Clarke quote: &amp;quot;Getting information from the internet is like getting a glass of water from the Niagara Falls.&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
| Watch for small planes&lt;br /&gt;
| Taking the popular Cessna 172 as an example, 1/1000th scale small planes would be about 8mm in length, and cruise at speeds of about 6cm/s, much slower than comparable flying insects. A Cessna of that size traveling at that speed would probably cause much more damage to itself than a person if it crashed into one, so the warning is probably there to protect the models rather than the guests. The planes are flying along 1-foot {{w|Flight level|flight levels}} according to the direction they are flying in, following the {{w|Flight level#Semicircular/hemispheric rule|semicircular rule}} of aviation.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Warning! Choking hazard! Keep small children away from ascending/descending airliners&lt;br /&gt;
| Airplanes are apparently small enough for children to fit into their mouths but large enough to potentially make them choke.&lt;br /&gt;
| In the US, small parts are defined by [https://www.cpsc.gov/Business--Manufacturing/Business-Education/Business-Guidance/Small-Parts-for-Toys-and-Childrens-Products 16 C.F.R. Part 1501.2] as fitting in a cylindrical test fixture of 1.25 inches diameter that approximates the size of the fully expanded throat of a child under three years old. Once scaled, any object smaller than 31.75 meters would fit in that cylinder. A lot of medium-sized and small airplanes would qualify. Furthermore, since pieces that break off during testing that simulates use or abuse by children could also pose a choking hazard, even large airliners are also a choking hazard because stripped wings and parts of the fuselage would fit in the required size.&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove safety caps&lt;br /&gt;
| This is a reference to the warning, &amp;quot;Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&amp;quot; from [[2411: 1/10,000th Scale World]]. It's possible that many visitors to that scaled world did not heed the warnings and complained to the scaled world's creators, causing them to cover pointy towers with safety caps for this scaled world. However, now there are [[Black Hat|people who apparently want to cause harm to others]], or at least don't care about not causing harm to others, by removing these safety caps.&lt;br /&gt;
The tip of the Burj Khalifa - the tallest building in the scale world - appears to be about a meter and a half wide, or 1.5mm at 1/1000th scale.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No open flames in Zeppelin area&lt;br /&gt;
| Zeppelins are filled with hydrogen due to its very low density, which allows them to float. However, it is also very flammable and prone to explosions. The most famous of these Zeppelin disasters was when the {{w|Hindenburg disaster|Hindenburg exploded}} in 1937.&lt;br /&gt;
| Because of hydrogen's flammability and explosiveness when exposed to oxygen, all modern airships use helium, which is a noble gas and therefore not flammable. Therefore, if Randall's scale model has airships of any sort, this makes the model inaccurate (unless Randall's model is supposed to represent the world several decades ago, in which case the neutrino detectors and some other features would be inaccurate).&lt;br /&gt;
|-&lt;br /&gt;
| Do not bother the meteor crater ducks&lt;br /&gt;
| Even though it is not specified which crater the one in the comic is supposed to represent, a typical meteor crater (say, {{w|Meteor Crater}} in Arizona) is over a kilometer wide, so at 1/1000 scale it could be a small duck pond of 1.186m diameter, and 17cm deep at its deepest point. This is (barely) enough space for a duck to swim in if filled to the brim with water. Meteor craters often leave behind lakes as they become filled with water, with examples being {{w|Lake Siljan}} in Europe. The ducks appear to be regular-sized as opposed to scaled down, showing that they were probably added afterwards as an attraction as opposed to them coming with the landscape.&lt;br /&gt;
| Even though a lot of craters are filled with lakes, Meteor Crater is not filled with water, or ducks, in real life. {{Citation needed}}&lt;br /&gt;
|-&lt;br /&gt;
| Trip hazard: The Gateway Arch&lt;br /&gt;
| The {{w|Gateway Arch}} is a monument in Saint Louis, Missouri. Being a 192 m high arch, once scaled it would be 19.2 cm high, ideal for tripping.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Drone altitude limit&lt;br /&gt;
| The FAA drone altitude limit is 400ft above the ground, which would be about 12cm in 1/1000th scale. This appears to be the number Randall is using, as the limit in the comic is about the same height as the pyramids, which are also around 400ft tall in the real world.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not mix up the USS Enterprises&lt;br /&gt;
| &lt;br /&gt;
The ship is presumably a model of the USS Enterprise (CVN-65), the longest naval vessel ever built, which would be 34cm long in 1/1000th scale.&lt;br /&gt;
The spaceship is the USS Enterprise (NCC-1701) from the Star Trek franchise.&lt;br /&gt;
It's unclear whether mixing up the models is prohibited because it would damage them, or simply because that's not where they are supposed to be.&lt;br /&gt;
The Starship Enterprise might be corroded by seawater, or unable to handle external pressure (spacecraft are designed for the exact opposite pressures in a vacuum). If lifted into the air, the Aircraft Carrier Enterprise would probably fall back down because it can't fly {{Citation needed}} (and be damaged or even destroyed upon hitting the ground or water surface), but then again, it's unclear how the model Enterprise is able to fly or hover.&lt;br /&gt;
The Enterprise from the JJ Abrams films has been seen to hide underwater and take off again without significant problems, and the Original Series version has been seen to fly (high) in the Earth's atmosphere on several occasions. However, it is unclear whether other versions of the Enterprise also possess this standard operational ability, nor which version is represented in the comic.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No connecting the Dead Sea to the ocean&lt;br /&gt;
| The surface of the Dead Sea is 430.5 metres (1,412 ft) below sea level, so connecting it to the ocean would cause catastrophic flooding of the area. If there are models of Israeli and Jordanian cities next to the Dead Sea, they could get damaged by the water. Also, the model world would be less accurate because the Dead Sea is not connected to the ocean in real life.&lt;br /&gt;
| This has actually been proposed: {{w|Mediterranean–Dead Sea Canal|Dead Sea Canal}}&lt;br /&gt;
|-&lt;br /&gt;
| Do not let ants into the Sudbury Neutrino Observatory&lt;br /&gt;
| The Sudbury Neutrino Observatory was a neutrino observatory located at the 2100-meter depth level of the Creighton Mine in Ontario, Canada.  It has since been upgraded into the SNOLAB facility.  At 1/1000th scale, its meters-scale tunnels would be millimeters across, and its 3,000-meter maximum depth would reach three meters underground.  This would make it ideal for habitation by ants, but as the mine is in rock, and not soil, extracting the ants after they get in would be much more difficult than most pest control operations.  Also, some types of ants would eat the insulation around the wires, causing electrical short-circuits and other problems, which would be bad because the model's neutrino detectors are apparently functional. (See the row about the south pole neutrino observatory.)&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Only one person on the Golden Gate Tightrope at a time&lt;br /&gt;
| The {{w|Golden Gate Bridge}} is a suspension bridge in San Francisco, 2.7 km long and 27 m wide. Scaled-down, it would be 2.7 m long and 2.7 cm wide, and it would be tempting to use it as a tightrope.&lt;br /&gt;
| In 1987, approximately 300,000 people [https://www.sfgate.com/local-donotuse/article/Golden-Gate-bridge-walk-1987-anniversary-disaster-13896571.php walked across the Golden Gate Bridge], which could be the largest weight it has supported: 80kg * 300,000 = 2.4*10^7kg. A visitor to the scaled world would expect to weigh a much as (1000^3) = 1 billion native scaled humans, above the [https://www.vibrationdata.com/golden.htm total mass of the bridge].&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove Statue of Liberty LEGO minifig&lt;br /&gt;
| Whoever has made this model has decided to use a small LEGO minifigure rather than a more accurately sculpted replica of the Statue of Liberty. The person would likely not want it to be removed because it would then have to be replaced.&lt;br /&gt;
| LEGO has released a [https://www.lego.com/en-us/product/magnet-statue-of-liberty-2016-853600 Statue of Liberty minifigure] which is 5.3cm tall. The real Statue of Liberty, from head to toe, is 46 meters tall. At 1/1000 scale this would be a 4.6cm figurine, so the LEGO minifigure would indeed be an appropriate representation at that scale.&lt;br /&gt;
|-&lt;br /&gt;
| Please stop releasing goldfish in the ocean. They keep eating the blue whales.&lt;br /&gt;
| Blue whales are the largest animal species in the world. They usually grow to about 20m long in real life, meaning that at 1/1000th scale they would be only 2cm long, meaning that they could be consumed by a goldfish. Goldfish are omnivores, so they would eat tiny blue whales. But they are also freshwater fish, so would they survive long enough in seawater to put the whales at risk? This could perhaps be considered carping. And perhaps Randall's customers have access to [https://mashable.com/2017/09/20/saltwater-bearing-goldfish-australia/ Australian goldfish].&lt;br /&gt;
| In the mouseover text, Randall mentions that if real blue whales were to be released into the 1/1000th scale ocean they would filter-feed on the miniature versions. Blue whales usually eat {{w|krill}}; the tiny whales would be about the same size, though nowhere near the same density, so any feeding whale would soon go hungry. However, a 15-foot (ca. 5 meter) diameter whale in a 30-foot (ca. 9 m) trench (ignoring displacement, for the moment) would most likely be too stressed to eat.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:[At the top of the image, inside the panel, a large title is floating in the air.]&lt;br /&gt;
:RULES&lt;br /&gt;
&lt;br /&gt;
:For visitors to my 1/1,000th scale world&lt;br /&gt;
&lt;br /&gt;
:1 meter = 1 km   1 ft = 1,000 ft&lt;br /&gt;
&lt;br /&gt;
:[Each of the following rules is written near a character or point of interest on the map.]&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Scale World]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205559</id>
		<title>2417: 1/1,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205559"/>
				<updated>2021-01-29T18:26:19Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Table */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2417&lt;br /&gt;
| date      = January 27, 2021&lt;br /&gt;
| title     = 1/1,000th Scale World&lt;br /&gt;
| image     = 1_1000th_scale_world.png&lt;br /&gt;
| titletext = We're worried that a regular whale will get into a 30-foot-deep ocean trench section and filter-feed on all the tiny whales.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a STATUE OF LIBERTY MINIFIG. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is the third comic in the [[:Category:Scale World|Scale World]] series, this time with a smaller scale-factor and thus a larger world than the earlier ones. As in the previous comics, [[Randall]] has a seemingly complete copy of Earth, this time at a 1:1000 scale, with various features and warnings labeled. Again, real-world features and phenomena are replicated at scale. As before, the model is very extensive, with in this case several underground neutrino detectors/observatories being replicated.&lt;br /&gt;
&lt;br /&gt;
Several of the warnings point out humorous consequences of the scale, such as non-scaled goldfish eating scaled-down blue whales.  Other than the usual homo sapiens, introduction of non-scaled animals into the scaled world (with consistently humorous consequences) is an addition to the earlier comics of the series.&lt;br /&gt;
&lt;br /&gt;
===Table===&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
| Keep hot objects off the ice sheet over the south pole neutrino observatory&lt;br /&gt;
| Hot objects may emit Cherenkov radiation, which would result in the observatory detecting false positives of neutrino observations. They may also melt the ice that shields the detectors from other particles that would trigger false positives&lt;br /&gt;
| The fact that people are not supposed to create false positives implies that the neutrino detector is functional.&lt;br /&gt;
|-&lt;br /&gt;
| Be patient: Niagara falls will take a few minutes to fill your water glass&lt;br /&gt;
| The flow rate is scaled down with the size. According to the [[what if]] ''{{what if|147|Niagara Straw}}, the Niagara Falls flow is regulated to 100,000 cubic feet per second on the tourist season and to 50,000 cubic feet per second offseason and at night. Once scaled to 1/1000, that flow would be 2.83 or 1.41ml per second. If a standard glass of water is 250ml, it would take about 90&amp;amp;ndash;180 seconds for the waterfall to fill it. &lt;br /&gt;
&lt;br /&gt;
However, a 1/1000th replica of scale Niagra falls would be over a meter wide, so without some kind of system to divert the whole flow into one spot, it would not be possible to fill a glass this quickly. Also, the height of the scaled-down Niagra falls would be 5cm, with another 5cm between the water level and the riverbed, so it might be difficult to fill a glass depending on its height.&lt;br /&gt;
| This item is likely to be a reference to the famous Arthur C. Clarke quote: &amp;quot;Getting information from the internet is like getting a glass of water from the Niagara Falls.&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
| Watch for small planes&lt;br /&gt;
| Taking the popular Cessna 172 as an example, 1/1000th scale small planes would be about 8mm in length, and cruise at speeds of about 6cm/s, much slower than comparable flying insects. A Cessna of that size traveling at that speed would probably cause much more damage to itself than a person if it crashed into one, so the warning is probably there to protect the models rather than the guests. The planes are flying along 1-foot {{w|Flight level|flight levels}} according to the direction they are flying in, following the {{w|Flight level#Semicircular/hemispheric rule|semicircular rule}} of aviation.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Warning! Choking hazard! Keep small children away from ascending/descending airliners&lt;br /&gt;
| Airplanes are apparently small enough for children to fit into their mouths but large enough to potentially make them choke.&lt;br /&gt;
| In the US, small parts are defined by [https://www.cpsc.gov/Business--Manufacturing/Business-Education/Business-Guidance/Small-Parts-for-Toys-and-Childrens-Products 16 C.F.R. Part 1501.2] as fitting in a cylindrical test fixture of 1.25 inches diameter that approximates the size of the fully expanded throat of a child under three years old. Once scaled, any object smaller than 31.75 meters would fit in that cylinder. A lot of medium-sized and small airplanes would qualify. Furthermore, since pieces that break off during testing that simulates use or abuse by children could also pose a choking hazard, even large airliners are also a choking hazard because stripped wings and parts of the fuselage would fit in the required size.&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove safety caps&lt;br /&gt;
| This is a reference to the warning, &amp;quot;Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&amp;quot; from [[2411: 1/10,000th Scale World]]. It's possible that many visitors to that scaled world did not heed the warnings and complained to the scaled world's creators, causing them to cover pointy towers with safety caps for this scaled world. However, now there are [[Black Hat|people who apparently want to cause harm to others]], or at least don't care about not causing harm to others, by removing these safety caps.&lt;br /&gt;
The tip of the Burj Khalifa - the tallest building in the scale world - appears to be about a meter and a half wide, or 1.5mm at 1/1000th scale.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No open flames in Zeppelin area&lt;br /&gt;
| Zeppelins are filled with hydrogen due to its very low density, which allows them to float. However, it is also very flammable and prone to explosions. The most famous of these Zeppelin disasters was when the {{w|Hindenburg disaster|Hindenburg exploded}} in 1937.&lt;br /&gt;
| Because of hydrogen's flammability and explosiveness when exposed to oxygen, all modern airships use helium, which is a noble gas and therefore not flammable. Therefore, if Randall's scale model has airships of any sort, this makes the model inaccurate (unless Randall's model is supposed to represent the world several decades ago, in which case the neutrino detectors and some other features would be inaccurate).&lt;br /&gt;
|-&lt;br /&gt;
| Do not bother the meteor crater ducks&lt;br /&gt;
| Even though it is not specified which crater the one in the comic is supposed to represent, a typical meteor crater (say, {{w|Meteor Crater}} in Arizona) is over a kilometer wide, so at 1/1000 scale it could be a small duck pond of 1.186m diameter, and 17cm deep at its deepest point. This is (barely) enough space for a duck to swim in if filled to the brim with water. Meteor craters often leave behind lakes as they become filled with water, with examples being {{w|Lake Siljan}} in Europe. The ducks appear to be regular-sized as opposed to scaled down, showing that they were probably added afterwards as an attraction as opposed to them coming with the landscape.&lt;br /&gt;
| Even though a lot of craters are filled with lakes, Meteor Crater is not filled with water, or ducks, in real life. {{Citation needed}}&lt;br /&gt;
|-&lt;br /&gt;
| Trip hazard: The Gateway Arch&lt;br /&gt;
| The {{w|Gateway Arch}} is a monument in Saint Louis, Missouri. Being a 192 m high arch, once scaled it would be 19.2 cm high, ideal for tripping.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Drone altitude limit&lt;br /&gt;
| The FAA drone altitude limit is 400ft above the ground, which would be about 12cm in 1/1000th scale. This appears to be the number Randall is using, as the limit in the comic is about the same height as the pyramids, which are also around 400ft tall in the real world.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not mix up the USS Enterprises&lt;br /&gt;
| &lt;br /&gt;
The ship is presumably a model of the USS Enterprise (CVN-65), the longest naval vessel ever built, which would be 34cm long in 1/1000th scale.&lt;br /&gt;
The spaceship is the USS Enterprise (NCC-1701) from the Star Trek franchise.&lt;br /&gt;
It's unclear whether mixing up the models is prohibited because it would damage them, or simply because that's not where they are supposed to be.&lt;br /&gt;
The Starship Enterprise might be corroded by seawater, or unable to handle external pressure (spacecraft are designed for the exact opposite pressures in a vacuum). If lifted into the air, the Aircraft Carrier Enterprise would probably fall back down because it can't fly {{Citation needed}} (and be damaged or even destroyed upon hitting the ground or water surface), but then again, it's unclear how the model Enterprise is able to fly or hover.&lt;br /&gt;
The Enterprise from the JJ Abrams films has been seen to hide underwater and take off again without significant problems, and the Original Series version has been seen to fly (high) in the Earth's atmosphere on several occasions. However, it is unclear whether other versions of the Enterprise also possess this standard operational ability, nor which version is represented in the comic.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No connecting the Dead Sea to the ocean&lt;br /&gt;
| The surface of the Dead Sea is 430.5 metres (1,412 ft) below sea level, so connecting it to the ocean would cause catastrophic flooding of the area. If there are models of Israeli and Jordanian cities next to the Dead Sea, they could get damaged by the water. Also, the model world would be less accurate because the Dead Sea is not connected to the ocean in real life.&lt;br /&gt;
| This has actually been proposed: {{w|Mediterranean–Dead Sea Canal|Dead Sea Canal}}&lt;br /&gt;
|-&lt;br /&gt;
| Do not let ants into the Sudbury Neutrino Observatory&lt;br /&gt;
| The Sudbury Neutrino Observatory was a neutrino observatory located at the 2100-meter depth level of the Creighton Mine in Ontario, Canada.  It has since been upgraded into the SNOLAB facility.  At 1/1000th scale, its meters-scale tunnels would be millimeters across, and its 3,000-meter maximum depth would reach three meters underground.  This would make it ideal for habitation by ants, but as the mine is in rock, and not soil, extracting the ants after they get in would be much more difficult than most pest control operations.  Also, some types of ants would eat the insulation around the wires, causing electrical short-circuits and other problems, which would be bad because the model's neutrino detectors are apparently functional. (See the row about the south pole neutrino observatory.)&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Only one person on the Golden Gate Tightrope at a time&lt;br /&gt;
| The {{w|Golden Gate Bridge}} is a suspension bridge in San Francisco, 2.7 km long and 27 m wide. Scaled-down, it would be 2.7 m long and 2.7 cm wide, and it would be tempting to use it as a tightrope.&lt;br /&gt;
| In 1987, approximately 300,000 people [https://www.sfgate.com/local-donotuse/article/Golden-Gate-bridge-walk-1987-anniversary-disaster-13896571.php walked across the Golden Gate Bridge], which could be the largest weight it has supported: 80kg * 300,000 = 2.4*10^7kg. A visitor to the scaled world would expect to weigh a much as (1000^3) = 1 billion native scaled humans, above the [https://www.vibrationdata.com/golden.htm total mass of the bridge].&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove Statue of Liberty LEGO minifig&lt;br /&gt;
| Whoever has made this model has decided to use a small LEGO minifigure rather than a more accurately sculpted replica of the Statue of Liberty. The person would likely not want it to be removed because it would then have to be replaced.&lt;br /&gt;
| LEGO has released a [https://www.lego.com/en-us/product/magnet-statue-of-liberty-2016-853600 Statue of Liberty minifigure] which is 5.3cm tall. The real Statue of Liberty, from head to toe, is 46 meters tall. At 1/1000 scale this would be a 4.6cm figurine, so the LEGO minifigure would indeed be an appropriate representation at that scale.&lt;br /&gt;
|-&lt;br /&gt;
| Please stop releasing goldfish in the ocean. They keep eating the blue whales.&lt;br /&gt;
| Blue whales usually grow to about 20m long in real life, meaning that at 1/1000th scale they would be only 2cm long, meaning that they could be consumed by a goldfish. Goldfish are omnivores, so they would eat tiny blue whales. But they are also freshwater fish, so would they survive long enough in seawater to put the whales at risk? This could perhaps be considered carping. And perhaps Randall's customers have access to [https://mashable.com/2017/09/20/saltwater-bearing-goldfish-australia/ Australian goldfish].&lt;br /&gt;
| In the mouseover text, Randall mentions that if real blue whales were to be released into the 1/1000th scale ocean they would filter-feed on the miniature versions. Blue whales usually eat {{w|krill}}; the tiny whales would be about the same size, though nowhere near the same density, so any feeding whale would soon go hungry. However, a 15-foot (ca. 5 meter) diameter whale in a 30-foot (ca. 9 m) trench (ignoring displacement, for the moment) would most likely be too stressed to eat.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:[At the top of the image, inside the panel, a large title is floating in the air.]&lt;br /&gt;
:RULES&lt;br /&gt;
&lt;br /&gt;
:For visitors to my 1/1,000th scale world&lt;br /&gt;
&lt;br /&gt;
:1 meter = 1 km   1 ft = 1,000 ft&lt;br /&gt;
&lt;br /&gt;
:[Each of the following rules is written near a character or point of interest on the map.]&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Scale World]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205538</id>
		<title>2417: 1/1,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205538"/>
				<updated>2021-01-29T15:01:04Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2417&lt;br /&gt;
| date      = January 27, 2021&lt;br /&gt;
| title     = 1/1,000th Scale World&lt;br /&gt;
| image     = 1_1000th_scale_world.png&lt;br /&gt;
| titletext = We're worried that a regular whale will get into a 30-foot-deep ocean trench section and filter-feed on all the tiny whales.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a STATUE OF LIBERTY MINIFIG. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is the third comic in the [[:Category:Scale World|Scale World]] series, this time with a smaller scale-factor and thus a larger world than the earlier ones. As in the previous comics, [[Randall]] has a seemingly complete copy of Earth, this time at a 1:1000 scale, with various features and warnings labeled. Again, real-world features and phenomena are replicated at scale. As before, the model is very extensive, with in this case several underground neutrino detectors/observatories being replicated.&lt;br /&gt;
&lt;br /&gt;
Several of the warnings point out humorous consequences of the scale, such as non-scaled goldfish eating scaled-down blue whales.  Introduction of non-scaled animals into the scaled world (with consistently humorous consequences) is a difference from the earlier comics of the series.&lt;br /&gt;
&lt;br /&gt;
===Table===&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
| Keep hot objects off the ice sheet over the south pole neutrino observatory&lt;br /&gt;
| Hot objects may emit Cherenkov radiation, which would result in the observatory detecting false positives of neutrino observations. They may also melt the ice that shields the detectors from other particles that would trigger false positives&lt;br /&gt;
| The fact that people are not supposed to create false positives implies that the neutrino detector is functional.&lt;br /&gt;
|-&lt;br /&gt;
| Be patient: Niagara falls will take a few minutes to fill your water glass&lt;br /&gt;
| The flow rate is scaled down with the size. According to the [[what if]] ''{{what if|147|Niagara Straw}}, the Niagara Falls flow is regulated to 100,000 cubic feet per second on the tourist season and to 50,000 cubic feet per second offseason and at night. Once scaled to 1/1000, that flow would be 2.83 or 1.41ml per second. If a standard glass of water is 250ml, it would take about 90&amp;amp;ndash;180 seconds for the waterfall to fill it. &lt;br /&gt;
&lt;br /&gt;
However, a 1/1000th replica of scale Niagra falls would be over a meter wide, so without some kind of system to divert the whole flow into one spot, it would not be possible to fill a glass this quickly. Also, the height of the scaled-down Niagra falls would be 5cm, with another 5cm between the water level and the riverbed, so it might be difficult to fill a glass depending on its height.&lt;br /&gt;
| This item is likely to be a reference to the famous Arthur C. Clarke quote: &amp;quot;Getting information from the internet is like getting a glass of water from the Niagara Falls.&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
| Watch for small planes&lt;br /&gt;
| Taking the popular Cessna 172 as an example, 1/1000th scale small planes would be about 8mm in length, and cruise at speeds of about 6cm/s, much slower than comparable flying insects. A Cessna of that size traveling at that speed would probably cause much more damage to itself than a person if it crashed into one, so the warning is probably there to protect the models rather than the guests. The planes are flying along 1-foot {{w|Flight level|flight levels}} according to the direction they are flying in, following the {{w|Flight level#Semicircular/hemispheric rule|semicircular rule}} of aviation.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Warning! Choking hazard! Keep small children away from ascending/descending airliners&lt;br /&gt;
| Airplanes are apparently small enough for children to fit into their mouths but large enough to potentially make them choke.&lt;br /&gt;
| In the US, small parts are defined by [https://www.cpsc.gov/Business--Manufacturing/Business-Education/Business-Guidance/Small-Parts-for-Toys-and-Childrens-Products 16 C.F.R. Part 1501.2] as fitting in a cylindrical test fixture of 1.25 inches diameter that approximates the size of the fully expanded throat of a child under three years old. Once scaled, any object smaller than 31.75 meters would fit in that cylinder. A lot of medium-sized and small airplanes would qualify. Furthermore, since pieces that break off during testing that simulates use or abuse by children could also pose a choking hazard, even large airliners are also a choking hazard because stripped wings and parts of the fuselage would fit in the required size.&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove safety caps&lt;br /&gt;
| This is a reference to the warning, &amp;quot;Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&amp;quot; from [[2411: 1/10,000th Scale World]]. It's possible that many visitors to that scaled world did not heed the warnings and complained to the scaled world's creators, causing them to cover pointy towers with safety caps for this scaled world. However, now there are [[Black Hat|people who apparently want to cause harm to others]], or at least don't care about not causing harm to others, by removing these safety caps.&lt;br /&gt;
The tip of the Burj Khalifa - the tallest building in the scale world - appears to be about a meter and a half wide, or 1.5mm at 1/1000th scale.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No open flames in Zeppelin area&lt;br /&gt;
| Zeppelins are filled with hydrogen due to its very low density, which allows them to float. However, it is also very flammable and prone to explosions. The most famous of these Zeppelin disasters was when the {{w|Hindenburg disaster|Hindenburg exploded}} in 1937.&lt;br /&gt;
| Because of hydrogen's flammability and explosiveness when exposed to oxygen, all modern airships use helium, which is a noble gas and therefore not flammable. Therefore, if Randall's scale model has airships of any sort, this makes the model inaccurate (unless Randall's model is supposed to represent the world several decades ago, in which case the neutrino detectors and some other features would be inaccurate).&lt;br /&gt;
|-&lt;br /&gt;
| Do not bother the meteor crater ducks&lt;br /&gt;
| Even though it is not specified which crater the one in the comic is supposed to represent, a typical meteor crater (say, {{w|Meteor Crater}} in Arizona) is over a kilometer wide, so at 1/1000 scale it could be a small duck pond of 1.186m diameter, and 17cm deep at its deepest point. This is (barely) enough space for a duck to swim in if filled to the brim with water. Meteor craters often leave behind lakes as they become filled with water, with examples being {{w|Lake Siljan}} in Europe. The ducks appear to be regular-sized as opposed to scaled down, showing that they were probably added afterwards as an attraction as opposed to them coming with the landscape.&lt;br /&gt;
| Even though a lot of craters are filled with lakes, Meteor Crater is not filled with water, or ducks, in real life. {{Citation needed}}&lt;br /&gt;
|-&lt;br /&gt;
| Trip hazard: The Gateway Arch&lt;br /&gt;
| The {{w|Gateway Arch}} is a monument in Saint Louis, Missouri. Being a 192 m high arch, once scaled it would be 19.2 cm high, ideal for tripping.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Drone altitude limit&lt;br /&gt;
| The FAA drone altitude limit is 400ft above the ground, which would be about 12cm in 1/1000th scale. This appears to be the number Randall is using, as the limit in the comic is about the same height as the pyramids, which are also around 400ft tall in the real world.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not mix up the USS Enterprises&lt;br /&gt;
| &lt;br /&gt;
The ship is presumably a model of the USS Enterprise (CVN-65), the longest naval vessel ever built, which would be 34cm long in 1/1000th scale.&lt;br /&gt;
The spaceship is the USS Enterprise (NCC-1701) from the Star Trek franchise.&lt;br /&gt;
It's unclear whether mixing up the models is prohibited because it would damage them, or simply because that's not where they are supposed to be.&lt;br /&gt;
The Starship Enterprise might be corroded by seawater, or unable to handle external pressure (spacecraft are designed for the exact opposite pressures in a vacuum). If lifted into the air, the Aircraft Carrier Enterprise would probably fall back down because it can't fly {{Citation needed}} (and be damaged or even destroyed upon hitting the ground or water surface), but then again, it's unclear how the model Enterprise is able to fly or hover.&lt;br /&gt;
The Enterprise from the JJ Abrams films has been seen to hide underwater and take off again without significant problems, and the Original Series version has been seen to fly (high) in the Earth's atmosphere on several occasions. However, it is unclear whether other versions of the Enterprise also possess this standard operational ability, nor which version is represented in the comic.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No connecting the Dead Sea to the ocean&lt;br /&gt;
| The surface of the Dead Sea is 430.5 metres (1,412 ft) below sea level, so connecting it to the ocean would cause catastrophic flooding of the area. If there are models of Israeli and Jordanian cities next to the Dead Sea, they could get damaged by the water. Also, the model world would be less accurate because the Dead Sea is not connected to the ocean in real life.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not let ants into the Sudbury Neutrino Observatory&lt;br /&gt;
| The Sudbury Neutrino Observatory was a neutrino observatory located at the 2100-meter depth level of the Creighton Mine in Ontario, Canada.  It has since been upgraded into the SNOLAB facility.  At 1/1000th scale, its meters-scale tunnels would be millimeters across, and its 3,000-meter maximum depth would reach three meters underground.  This would make it ideal for habitation by ants, but as the mine is in rock, and not soil, extracting the ants after they get in would be much more difficult than most pest control operations.  Also, some types of ants would eat the insulation around the wires, causing electrical short-circuits and other problems, which would be bad because the model's neutrino detectors are apparently functional. (See the row about the south pole neutrino observatory.)&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Only one person on the Golden Gate Tightrope at a time&lt;br /&gt;
| The {{w|Golden Gate Bridge}} is a suspension bridge in San Francisco, 2.7 km long and 27 m wide. Scaled-down, it would be 2.7 m long and 2.7 cm wide, and it would be tempting to use it as a tightrope.&lt;br /&gt;
| In 1987, approximately 300,000 people [https://www.sfgate.com/local-donotuse/article/Golden-Gate-bridge-walk-1987-anniversary-disaster-13896571.php walked across the Golden Gate Bridge], which could be the largest weight it has supported: 80kg * 300,000 = 2.4*10^7kg. A visitor to the scaled world would expect to weigh a much as (1000^3) = 1 billion native scaled humans, above the [https://www.vibrationdata.com/golden.htm total mass of the bridge].&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove Statue of Liberty LEGO minifig&lt;br /&gt;
| Whoever has made this model has decided to use a small LEGO minifigure rather than a more accurately sculpted replica of the Statue of Liberty. The person would likely not want it to be removed because it would then have to be replaced.&lt;br /&gt;
| LEGO has released a [https://www.lego.com/en-us/product/magnet-statue-of-liberty-2016-853600 Statue of Liberty minifigure] which is 5.3cm tall. The real Statue of Liberty, from head to toe, is 46 meters tall. At 1/1000 scale this would be a 4.6cm figurine, so the LEGO minifigure would indeed be an appropriate representation at that scale.&lt;br /&gt;
|-&lt;br /&gt;
| Please stop releasing goldfish in the ocean. They keep eating the blue whales.&lt;br /&gt;
| Blue whales usually grow to about 20m long in real life, meaning that at 1/1000th scale they would be only 2cm long, meaning that they could be consumed by a goldfish. Goldfish are omnivores, so they would eat tiny blue whales. But they are also freshwater fish, so would they survive long enough in seawater to put the whales at risk? This could perhaps be considered carping. And perhaps Randall's customers have access to [https://mashable.com/2017/09/20/saltwater-bearing-goldfish-australia/ Australian goldfish].&lt;br /&gt;
| In the mouseover text, Randall mentions that if real blue whales were to be released into the 1/1000th scale ocean they would filter-feed on the miniature versions. Blue whales usually eat {{w|krill}}; the tiny whales would be about the same size, though nowhere near the same density, so any feeding whale would soon go hungry. However, a 15-foot (ca. 5 meter) diameter whale in a 30-foot (ca. 9 m) trench (ignoring displacement, for the moment) would most likely be too stressed to eat.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:[At the top of the image, inside the panel, a large title is floating in the air.]&lt;br /&gt;
:RULES&lt;br /&gt;
&lt;br /&gt;
:For visitors to my 1/1,000th scale world&lt;br /&gt;
&lt;br /&gt;
:1 meter = 1 km   1 ft = 1,000 ft&lt;br /&gt;
&lt;br /&gt;
:[Each of the following rules is written near a character or point of interest on the map.]&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Scale World]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205519</id>
		<title>2417: 1/1,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205519"/>
				<updated>2021-01-29T00:55:45Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Table */ meh&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2417&lt;br /&gt;
| date      = January 27, 2021&lt;br /&gt;
| title     = 1/1,000th Scale World&lt;br /&gt;
| image     = 1_1000th_scale_world.png&lt;br /&gt;
| titletext = We're worried that a regular whale will get into a 30-foot-deep ocean trench section and filter-feed on all the tiny whales.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a STATUE OF LIBERTY MINIFIG. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is the third comic in the [[:Category:Scale World|Scale World]] series, this time with a smaller scale and thus a larger world than the first. As in the previous comics, [[Randall]] has another seemingly complete copy of Earth, this time at a 1:1000 scale, with various features and warnings labeled. Again, real-world features and phenomena are replicated at scale. As before, the model is very extensive, with several underground neutrino detectors/observatories being replicated.&lt;br /&gt;
&lt;br /&gt;
Several of the warnings point out humorous consequences of the scale, such as non-scale goldfish eating scaled-down blue whales.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
===Table===&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
| Keep hot objects off the ice sheet over the south pole neutrino observatory&lt;br /&gt;
| Hot objects may emit Cherenkov radiation, which would result in the observatory detecting false positives of neutrino observations. They may also melt the ice that shields the detectors from other particles that would trigger false positives&lt;br /&gt;
| The fact that people are not supposed to create false positives implies that the neutrino detector is functional.&lt;br /&gt;
|-&lt;br /&gt;
| Be patient: Niagara falls will take a few minutes to fill your water glass&lt;br /&gt;
| The flow rate is scaled down with the size. According to the [[what if]] ''{{what if|147|Niagara Straw}}, the Niagara Falls flow is regulated to 100,000 cubic feet per second on the tourist season and to 50,000 cubic feet per second offseason and at night. Once scaled to 1/1000, that flow would be 2.83 or 1.41ml per second. If a standard glass of water is 250ml, it would take about 90&amp;amp;ndash;180 seconds for the waterfall to fill it. &lt;br /&gt;
&lt;br /&gt;
However, a 1/1000th replica of scale Niagra falls would be over a meter wide, so without some kind of system to divert the whole flow into one spot, it would not be possible to fill a glass this quickly. Also, the height of the scaled-down Niagra falls would be 5cm, with another 5cm between the water level and the riverbed, so it might be difficult to fill a glass depending on its height.&lt;br /&gt;
| This item is likely to be a reference to the famous Arthur C. Clarke quote: &amp;quot;Getting information from the internet is like getting a glass of water from the Niagara Falls.&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
| Watch for small planes&lt;br /&gt;
| Taking the popular Cessna 172 as an example, 1/1000th scale small planes would be about 8mm in length, and cruise at speeds of about 6cm/s, much slower than comparable flying insects. A Cessna of that size traveling at that speed would probably cause much more damage to itself than a person if it crashed into one, so the warning is probably there to protect the models rather than the guests. &lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Warning! Choking hazard! Keep small children away from ascending/descending airliners&lt;br /&gt;
| Airplanes are apparently small enough for children to fit into their mouths but large enough to potentially make them choke.&lt;br /&gt;
| In the US, small parts are defined by [https://www.cpsc.gov/Business--Manufacturing/Business-Education/Business-Guidance/Small-Parts-for-Toys-and-Childrens-Products 16 C.F.R. Part 1501.2] as fitting in a cylindrical test fixture of 1.25 inches diameter that approximates the size of the fully expanded throat of a child under three years old. Once scaled, any object smaller than 31.75 meters would fit in that cylinder. A lot of medium-sized and small airplanes would qualify. Furthermore, since pieces that break off during testing that simulates use or abuse by children could also pose a choking hazard, even large airliners are also a choking hazard because stripped wings and parts of the fuselage would fit in the required size.&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove safety caps&lt;br /&gt;
| This is a reference to the warning, &amp;quot;Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&amp;quot; from [[2411: 1/10,000th Scale World]]. It's possible that many visitors to that scaled world did not heed the warnings and complained to the scaled world's creators, causing them to cover pointy towers with safety caps for this scaled world. However, now there are [[Black Hat|people who apparently want to cause harm to others]], or at least don't care about not causing harm to others, by removing these safety caps.&lt;br /&gt;
The tip of the Burj Khalifa - the tallest building in the scale world - appears to be about a meter and a half wide, or 1.5mm at 1/1000th scale.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No open flames in Zeppelin area&lt;br /&gt;
| Zeppelins are filled with hydrogen due to its very low density, which allows them to float. However, it is also very flammable and prone to explosions. The most famous of these Zeppelin disasters was when the {{w|Hindenburg disaster|Hindenburg exploded}} in 1937.&lt;br /&gt;
| Because of hydrogen's flammability and explosiveness when exposed to oxygen, all modern airships use helium, which is a noble gas and therefore not flammable. Therefore, if Randall's scale model has airships of any sort, then makes the model inaccurate (unless Randall's model is supposed to represent the world several decades ago, in which case the neutrino detectors and some other features would be inaccurate).&lt;br /&gt;
|-&lt;br /&gt;
| Do not bother the meteor crater ducks&lt;br /&gt;
| Meteor Crater in Arizona is over a kilometer wide, so at 1/1000 scale it could be a small duck pond of 1.186m diameter, and 17cm deep at its deepest point. This is (barely) enough space for a duck to swim in if filled to the brim with water.&lt;br /&gt;
| Meteor Crater is not filled with water, or ducks, in real life. {{Citation needed}}&lt;br /&gt;
|-&lt;br /&gt;
| Trip hazard: The Gateway Arch&lt;br /&gt;
| The {{w|Gateway Arch}} is a monument in Saint Louis, Missouri. Being a 192 m high arch, once scaled it would be 19.2 cm high, ideal for tripping.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Drone altitude limit&lt;br /&gt;
| The FAA drone altitude limit is 400ft above the ground, which would be about 12cm in 1/1000th scale. This appears to be the number Randall is using, as the limit in the comic is about the same height as the pyramids, which are also around 400ft tall in the real world.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not mix up the USS Enterprises&lt;br /&gt;
| &lt;br /&gt;
The ship is presumably a model of the USS Enterprise (CVN-65), the longest naval vessel ever built, which would be 34cm long in 1/1000th scale.&lt;br /&gt;
The spaceship is the USS Enterprise (NCC-1701) from the Star Trek franchise.&lt;br /&gt;
It's unclear whether mixing up the models is prohibited because it would damage them, or simply because that's not where they are supposed to be.&lt;br /&gt;
The Starship Enterprise might be corroded by seawater, or unable to handle external pressure (spacecraft are designed for the exact opposite pressures in a vacuum). If lifted into the air, the Aircraft Carrier Enterprise would probably fall back down because it can't fly {{Citation needed}} (and be damaged or even destroyed upon hitting the ground or water surface), but then again, it's unclear how the model Enterprise is able to fly or hover.&lt;br /&gt;
The Enterprise from the JJ Abrams films has been seen to hide underwater and take off again without significant problems, and the Original Series version has been seen to fly (high) in the Earth's atmosphere on several occasions. However, it is unclear whether other versions of the Enterprise also possess this standard operational ability, nor which version is represented in the comic.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No connecting the Dead Sea to the ocean&lt;br /&gt;
| The surface of the Dead Sea is 430.5 metres (1,412 ft) below sea level, so connecting it to the ocean would cause catastrophic flooding of the area. If there are models of Israeli and Jordanian cities next to the Dead Sea, they could get damaged by the water. Also, the model world would be less accurate because the Dead Sea is not connected to the ocean in real life.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not let ants into the Sudbury Neutrino Observatory&lt;br /&gt;
| The Sudbury Neutrino Observatory was a neutrino observatory located at the 2100-meter depth level of the Creighton Mine in Ontario, Canada.  It has since been upgraded into the SNOLAB facility.  At 1/1000th scale, its meters-scale tunnels would be millimeters across, and its 3,000-meter maximum depth would reach three meters underground.  This would make it ideal for habitation by ants, but as the mine is in rock, and not soil, extracting the ants after they get in would be much more difficult than most pest control operations.  Also, some types of ants would eat the insulation around the wires, causing electrical short-circuits and other problems, which would be bad because the model's neutrino detectors are apparently functional. (See the row about the south pole neutrino observatory.)&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Only one person on the Golden Gate Tightrope at a time&lt;br /&gt;
| The {{w|Golden Gate Bridge}} is a suspension bridge in San Francisco, 2.7 km long and 27 m wide. Scaled-down, it would be 2.7 m long and 2.7 cm wide, and it would be tempting to use it as a tightrope.&lt;br /&gt;
| In 1987, approximately 300,000 people [https://www.sfgate.com/local-donotuse/article/Golden-Gate-bridge-walk-1987-anniversary-disaster-13896571.php walked across the Golden Gate Bridge], which could be the largest weight it has supported: 80kg * 300,000 = 2.4*10^7kg. A visitor to the scaled world would expect to weigh a much as (1000^3) = 1 billion native scaled humans, above the [https://www.vibrationdata.com/golden.htm total mass of the bridge].&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove Statue of Liberty LEGO minifig&lt;br /&gt;
| Whoever has made this model has decided to use a small LEGO minifigure rather than a more accurately sculpted replica of the Statue of Liberty. The person would likely not want it to be removed because it would then have to be replaced.&lt;br /&gt;
| LEGO has released a [https://www.lego.com/en-us/product/magnet-statue-of-liberty-2016-853600 Statue of Liberty minifigure] which is 5.3cm tall. The real Statue of Liberty, from head to toe, is 46 meters tall. At 1/1000 scale this would be a 4.6cm figurine, so the LEGO minifigure would indeed be an appropriate representation at that scale.&lt;br /&gt;
|-&lt;br /&gt;
| Please stop releasing goldfish in the ocean. They keep eating the blue whales.&lt;br /&gt;
| Blue whales usually grow to about 20m long in real life, meaning that at 1/1000th scale they would be only 2cm long, meaning that they could be consumed by a goldfish. Goldfish are omnivores, so they would eat tiny blue whales. But they are also freshwater fish, so would they survive long enough in seawater to put the whales at risk? This could perhaps be considered carping. And perhaps Randall's customers have access to [https://mashable.com/2017/09/20/saltwater-bearing-goldfish-australia/ Australian goldfish].&lt;br /&gt;
| This also raises the question of where one would get such tiny blue whales. In the mouseover text, Randall mentions that if real blue whales were to be released into the 1/1000th scale ocean they would filter-feed on the miniature versions. Blue whales usually eat minuscule krill; however, the tiny whales would provide a similarly-sized substitute.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:[At the top of the image, inside the panel, a large title is floating in the air.]&lt;br /&gt;
:RULES&lt;br /&gt;
&lt;br /&gt;
:For visitors to my 1/1,000th scale world&lt;br /&gt;
&lt;br /&gt;
:1 meter = 1 km   1 ft = 1,000 ft&lt;br /&gt;
&lt;br /&gt;
:[Each of the following rules is written near a character or point of interest on the map.]&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Scale World]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205504</id>
		<title>2417: 1/1,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2417:_1/1,000th_Scale_World&amp;diff=205504"/>
				<updated>2021-01-28T19:00:12Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Table */ was going to say 1.5 to 3 minutes, but the paragraph already used the &amp;quot;.&amp;quot; separator differently and I couldn't bear to write &amp;quot;1,5&amp;quot;&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2417&lt;br /&gt;
| date      = January 27, 2021&lt;br /&gt;
| title     = 1/1,000th Scale World&lt;br /&gt;
| image     = 1_1000th_scale_world.png&lt;br /&gt;
| titletext = We're worried that a regular whale will get into a 30-foot-deep ocean trench section and filter-feed on all the tiny whales.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a STATUE OF LIBERTY MINIFIG. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is the third comic in the [[:Category:Scale World|Scale World]] series, this time with a smaller scale and thus a larger world than the first. As in the previous comics, [[Randall]] has another seemingly complete copy of Earth, this time at a 1:1000 scale, with various features and warnings labeled. Again, real-world features and phenomena are replicated at scale. As before, the model is very extensive, with several underground neutrino detectors/observatories being replicated.&lt;br /&gt;
&lt;br /&gt;
Several of the warnings point out humorous consequences of the scale, such as goldfish eating blue whales.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
===Table===&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
| Keep hot objects off the ice sheet over the south pole neutrino observatory&lt;br /&gt;
| Hot objects may emit Cherenkov radiation, which would result in the observatory detecting false positives of neutrino observations. They may also melt the ice that shields the detectors from other particles that would trigger false positives&lt;br /&gt;
| The fact that people are not supposed to create false positives implies that the neutrino detector is functional.&lt;br /&gt;
|-&lt;br /&gt;
| Be patient: Niagara falls will take a few minutes to fill your water glass&lt;br /&gt;
| The flow rate is scaled down with the size. According to the [[what if]] ''{{what if|147|Niagara Straw}}, the Niagara Falls flow is regulated to 100.000 cubic feet per second on the tourist season and to 50.000 cubic feet per second offseason and at night. Once scaled to 1/1000, that flow would be 2.83 or 1.41ml per second. If a standard glass of water is 250ml, it would take about 90&amp;amp;ndash;180 seconds for the waterfall to fill it. &lt;br /&gt;
&lt;br /&gt;
However, a 1/1000th replica of scale Niagra falls would be over a meter wide, so without some kind of system to divert the whole flow into one spot, it would not be possible to fill a glass this quickly. Also, the height of the scaled-down Niagra falls would be 5cm, with another 5cm between the water level and the riverbed, so it might be difficult to fill a glass depending on its height.&lt;br /&gt;
| This item is likely to be a reference to the famous Arthur C. Clarke quote: &amp;quot;Getting information from the internet is like getting a glass of water from the Niagara Falls.&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
| Watch for small planes&lt;br /&gt;
| Taking the popular Cessna 172 as an example, 1/1000th scale small planes would be about 8mm in length, and cruise at speeds of about 6cm/s, much slower than comparable flying insects. A Cessna of that size traveling at that speed would probably cause much more damage to itself than a person if it crashed into one, so the warning is probably there to protect the models rather than the guests. &lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Warning! Choking hazard! Keep small children away from ascending/descending airliners&lt;br /&gt;
| Airplanes are apparently small enough for children to fit into their mouths but large enough to potentially make them choke.&lt;br /&gt;
| In the US, small parts are defined by [https://www.cpsc.gov/Business--Manufacturing/Business-Education/Business-Guidance/Small-Parts-for-Toys-and-Childrens-Products 16 C.F.R. Part 1501.2] as fitting in a cylindrical test fixture of 1.25 inches diameter that approximates the size of the fully expanded throat of a child under three years old. Once scaled, any object smaller than 31.75 meters would fit in that cylinder. A lot of medium-sized and small airplanes would qualify. Furthermore, since pieces that break off during testing that simulates use or abuse by children could also pose a choking hazard, even large airliners are also a choking hazard because stripped wings and parts of the fuselage would fit in the required size.&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove safety caps&lt;br /&gt;
| This is a reference to the warning, &amp;quot;Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&amp;quot; from [[2411: 1/10,000th Scale World]]. It's possible that many visitors to that scaled world did not heed the warnings and complained to the scaled world's creators, causing them to cover pointy towers with safety caps for this scaled world. However, now there are [[Black Hat|people who apparently want to cause harm to others]], or at least don't care about not causing harm to others, by removing these safety caps.&lt;br /&gt;
The tip of the Burj Khalifa - the tallest building in the scale world - appears to be about a meter and a half wide, or 1.5mm at 1/1000th scale.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No open flames in Zeppelin area&lt;br /&gt;
| Zeppelins are filled with hydrogen due to its very low density, which allows them to float. However, it is also very flammable and prone to explosions. The most famous of these Zeppelin disasters was when the {{w|Hindenburg disaster|Hindenburg exploded}} in 1937.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not bother the meteor crater ducks&lt;br /&gt;
| Meteor Crater in Arizona is over a kilometer wide, so at 1/1000 scale it could be a small duck pond of 1.186m diameter, and 17cm deep at its deepest point. This is (barely) enough space for a duck to swim in if filled to the brim with water.&lt;br /&gt;
| Meteor Crater is not filled with water, or ducks, in real life. &lt;br /&gt;
|-&lt;br /&gt;
| Trip hazard: The Gateway Arch&lt;br /&gt;
| The {{w|Gateway Arch}} is a monument in Saint Louis, Missouri. Being a 192 m high arch, once scaled it would be 19.2 cm high, ideal for tripping.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Drone altitude limit&lt;br /&gt;
| The FAA drone altitude limit is 400ft above the ground, which would be about 12cm in 1/1000th scale. This appears to be the number Randall is using, as the limit in the comic is about the same height as the pyramids, which are also around 400ft tall in the real world.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not mix up the USS Enterprises&lt;br /&gt;
| &lt;br /&gt;
The ship is presumably a model of the USS Enterprise (CVN-65), the longest naval vessel ever built, which would be 34cm long in 1/1000th scale.&lt;br /&gt;
The spaceship is the USS Enterprise (NCC-1701) from the Star Trek franchise.&lt;br /&gt;
It's unclear whether mixing up the models is prohibited because it would damage them, or simply because that's not where they are supposed to be.&lt;br /&gt;
The Starship Enterprise might be corroded by seawater, or unable to handle external pressure (spacecraft are designed for the exact opposite pressures in a vacuum). If lifted into the air, the Aircraft Carrier Enterprise would probably fall back down because it can't fly {{Citation needed}} (and be damaged or even destroyed upon hitting the ground or water surface), but then again, it's unclear how the model Enterprise is able to fly or hover.&lt;br /&gt;
The Enterprise from the JJ Abrams films has been seen to hide underwater and take off again without significant problems, and the Original Series version has been seen to fly (high) in the Earth's atmosphere on several occasions. However, it is unclear whether other versions of the Enterprise also possess this standard operational ability, nor which version is represented in the comic.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| No connecting the Dead Sea to the ocean&lt;br /&gt;
| The surface of the Dead Sea is 430.5 metres (1,412 ft) below sea level, so connecting it to the ocean would cause catastrophic flooding of the area. If there are models of Israeli and Jordanian cities next to the Dead Sea, they could get damaged by the water. Also, the model world would be less accurate because the Dead Sea is not connected to the ocean in real life.&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Do not let ants into the Sudbury Neutrino Observatory&lt;br /&gt;
| The Sudbury Neutrino Observatory was a neutrino observatory located at the 2100-meter depth level of the Creighton Mine in Ontario, Canada.  It has since been upgraded into the SNOLAB facility.  At 1/1000th scale, its meters-scale tunnels would be millimeters across, and its 3,000-meter maximum depth would reach three meters underground.  This would make it ideal for habitation by ants, but as the mine is in rock, and not soil, extracting the ants after they get in would be much more difficult than most pest control operations.  Also, some types of ants would eat the insulation around the wires, causing electrical short-circuits and other problems, which would be bad because the model's neutrino detectors are apparently functional. (See the row about the south pole neutrino observatory.)&lt;br /&gt;
| &lt;br /&gt;
|-&lt;br /&gt;
| Only one person on the Golden Gate Tightrope at a time&lt;br /&gt;
| The {{w|Golden Gate Bridge}} is a suspension bridge in San Francisco, 2.7 km long and 27 m wide. Scaled-down, it would be 27 m long and 2.7 cm wide, and it would be tempting to use it as a tightrope.&lt;br /&gt;
| In 1987, approximately 300,000 people [https://www.sfgate.com/local-donotuse/article/Golden-Gate-bridge-walk-1987-anniversary-disaster-13896571.php walked across the Golden Gate Bridge], which could be the largest weight it has supported: 80kg * 300,000 = 2.4*10^7kg. A visitor to the scaled world would expect to weigh (1000^3) times as much as a standard human: 8*(10^10), above the [https://www.vibrationdata.com/golden.htm total mass of the bridge]: 3.8*(10^8)&lt;br /&gt;
|-&lt;br /&gt;
| Do not remove Statue of Liberty LEGO minifig&lt;br /&gt;
| Whoever has made this model has decided to use a small LEGO minifigure rather than a more accurately sculpted replica of the Statue of Liberty. The person would likely not want it to be removed because it would then have to be replaced.&lt;br /&gt;
| LEGO has released a [https://www.lego.com/en-us/product/magnet-statue-of-liberty-2016-853600 Statue of Liberty minifigure] which is 5.3cm tall. The real Statue of Liberty, from head to toe, is 46 meters tall. At 1/1000 scale this would be a 4.6cm figurine, so the LEGO minifigure would indeed be an appropriate representation at that scale.&lt;br /&gt;
|-&lt;br /&gt;
| Please stop releasing goldfish in the ocean. They keep eating the blue whales.&lt;br /&gt;
| Blue whales usually grow to about 20m long in real life, meaning that at 1/1000th scale they would be only 2cm long, meaning that they could easily be consumed by a goldfish. Goldfish are omnivores, so they would eat tiny blue whales. But they are also freshwater fish, so would they survive long enough in seawater to put the whales at risk? This could perhaps be considered carping. And perhaps Randall's customers have access to [https://mashable.com/2017/09/20/saltwater-bearing-goldfish-australia/ Australian goldfish].&lt;br /&gt;
| This also raises the question of where one would get such tiny blue whales. In the mouseover text, Randall mentions that if real blue whales were to be released into the 1/1000th scale ocean they would filter-feed on the miniature versions. Blue whales usually eat minuscule krill; however, the tiny whales would provide a similarly-sized substitute.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:[At the top of the image, inside the panel, a large title is floating in the air.]&lt;br /&gt;
:RULES&lt;br /&gt;
&lt;br /&gt;
:For visitors to my 1/1,000th scale world&lt;br /&gt;
&lt;br /&gt;
:1 meter = 1 km   1 ft = 1,000 ft&lt;br /&gt;
&lt;br /&gt;
:[Each of the following rules is written near a character or point of interest on the map.]&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Scale World]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205374</id>
		<title>2416: Trash Compactor Party</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205374"/>
				<updated>2021-01-26T22:51:42Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */ &amp;quot;is&amp;quot; would be correct, but trimming a few words can avoid the question&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2416&lt;br /&gt;
| date      = January 25, 2021&lt;br /&gt;
| title     = Trash Compactor Party&lt;br /&gt;
| image     = trash_compactor_party.png&lt;br /&gt;
| titletext = What an incredible smell you've discovered.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a FORMER SOCIAL-DISTANCER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
Randall has gotten tired of social distancing and wants to do the exact opposite when he can. The exact opposite of social distancing would be being crushed together by some sort of compactor.&lt;br /&gt;
&lt;br /&gt;
Cueball and Megan are trying to push the walls of the trash compactor back in order to prevent it from pushing them closer to other people. The other attendees appear to be anxiously shying away from the inexorably increasing proximity of both of their neighbouring guests. This reflects the common current trend for many normal people to maintain exagerated personal space when meeting or passing other people out and about, compared with the pre-COVID era.&lt;br /&gt;
&lt;br /&gt;
Though a significant proportion of the population seem to have returned to being oblivious to the pandemic (or to have stayed there, through it all) and eagerly socialise, often grossly breaking rules laid down to protect people, this gathering may have been mooted as a 'Covid-safe' gathering within the advice applicable to their locale (and time, as this is for &amp;quot;when it is all over&amp;quot;), and the narrowing space is perhaps even a surprise to most of them.&lt;br /&gt;
&lt;br /&gt;
The trash compactor scenario is a TV and film {{tvtropes|TheWallsAreClosingIn|trope}}. The title text references a high-profile instance of the trope from the original {{w|Star Wars (film)|''Star Wars'' film}} (later retitled ''Star Wars: Episode IV &amp;amp;mdash; A New Hope''). {{w|Han Solo}} utters this quip shortly after he and several other main characters bail out of a firefight and land in a room full of trash. The walls then start closing in and, as in the comic, the characters are not enthused about being pushed ever closer together, and seek to push back on the walls before being crushed. Here, the quote also expresses a sense of (a new) hope: since a common symptom of COVID-19 is a loss of smell, the fact that the characters are all able to smell their surroundings suggests that the pandemic is gone.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[From left to right, Megan (sitting), Science Girl, White Hat, Ponytail, and Cueball are having a party. There are two machines on either side of the scene, moving the walls on the left and right ever-closer in. The machines have pistons which push the walls together, and their rods are more than long enough for the walls to meet in the middle and crush the group. Cueball and Megan are pressed up against the walls, trying to slow the advance. The other three characters appear anxious.]&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:I'm planning a trash-compactor-themed party for when this is all over so we can get used to standing near each other again. &lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring White Hat]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:COVID-19]]&lt;br /&gt;
[[Category:Star Wars]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205358</id>
		<title>2416: Trash Compactor Party</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205358"/>
				<updated>2021-01-26T15:45:59Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2416&lt;br /&gt;
| date      = January 26, 2021&lt;br /&gt;
| title     = Trash Compactor Party&lt;br /&gt;
| image     = trash_compactor_party.png&lt;br /&gt;
| titletext = What an incredible smell you've discovered.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a FORMER SOCIAL-DISTANCER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
Randall has gotten tired of social distancing and wants to do the exact opposite when he can. The exact opposite of social distancing would be being crushed together by some sort of compactor.&lt;br /&gt;
&lt;br /&gt;
Cueball and Megan are trying to push the walls of the trash compactor back in order to prevent it from pushing them closer to other people. The other attendees appear to be anxiously shying away from the inexorably increasing proximity of both of their neighbouring guests. This reflects the common current trend for many normal people to maintain exagerated personal space when meeting or passing other people out and about, compared with the pre-COVID era.&lt;br /&gt;
&lt;br /&gt;
Though there is a significant proportion of the population who seem to have returned to being oblivious to the pandemic (or have stayed there, through it all) and eagerly socialise, often grossly breaking rules laid down to protect people, this gathering may have been mooted as a 'Covid-safe' gathering within the advice applicable to their locale (and time, as this is for &amp;quot;when it is all over&amp;quot;), and the narrowing space is perhaps even a surprise to most of them.&lt;br /&gt;
&lt;br /&gt;
The trash compactor scenario is a TV and film {{tvtropes|TheWallsAreClosingIn|trope}}. The title text references a high-profile instance of the trope from the original {{w|Star Wars (film)|''Star Wars'' film}} (later retitled ''Star Wars: Episode IV &amp;amp;mdash; A New Hope''). Han Solo utters this quip shortly after he and several other main characters bail out of a firefight and land in a room full of trash. The walls then start closing in and, as in the comic, the characters are not enthused about being pushed ever closer together, and seek to push back on the walls before being crushed. Here, the quote also expresses a sense of (a new) hope: since a common symptom of COVID-19 is a loss of smell, the fact that the characters are all able to smell their surroundings suggests that the pandemic is gone.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[From left to right, Megan (sitting), Science Girl, White Hat, Ponytail, and Cueball are having a party. There are two machines on either side of the scene, moving the walls on the left and right ever-closer in. The machines have pistons which push the walls together, and their rods are more than long enough for the walls to meet in the middle and crush the group. Cueball and Megan are pressed up against the walls, trying to slow the advance. The other three characters appear anxious.]&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:I'm planning a trash-compactor-themed party for when this is all over so we can get used to standing near each other again. &lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring White Hat]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:COVID-19]]&lt;br /&gt;
[[Category:Star Wars]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205356</id>
		<title>2416: Trash Compactor Party</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205356"/>
				<updated>2021-01-26T14:41:01Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2416&lt;br /&gt;
| date      = January 26, 2021&lt;br /&gt;
| title     = Trash Compactor Party&lt;br /&gt;
| image     = trash_compactor_party.png&lt;br /&gt;
| titletext = What an incredible smell you've discovered.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a FORMER SOCIAL-DISTANCER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
Randall has gotten tired of social distancing and wants to do the exact opposite when he can. The exact opposite of social distancing would be being crushed together by some sort of compactor.&lt;br /&gt;
&lt;br /&gt;
Cueball and Megan are trying to push the walls of the trash compactor back in order to prevent it from pushing them closer to other people. The other attendees appear to be anxiously shying away from the inexorably increasing proximity of both of their neighbouring guests. This reflects the common current trend for many normal people to maintain exagerated personal space when meeting or passing other people out and about, compared with the pre-COVID era.&lt;br /&gt;
&lt;br /&gt;
Though there is a significant proportion of the population who seem to have returned to being oblivious to the pandemic (or have stayed there, through it all) and eagerly socialise, often grossly breaking rules laid down to protect people, this gathering may have been mooted as a 'Covid-safe' gathering within the advice applicable to their locale (and time, as this is for &amp;quot;when it is all over&amp;quot;), and the narrowing space is perhaps even a surprise to most of them.&lt;br /&gt;
&lt;br /&gt;
The trash compactor scenario is a TV and film {{tvtropes|TheWallsAreClosingIn|trope}}. The title text references a high-profile instance of the trope from the original {{w|Star Wars (film)|''Star Wars'' film}} (later retitled ''Star Wars: Episode IV &amp;amp;mdash; A New Hope''). Han Solo utters this quip shortly after he and several other main characters bail out of a firefight and land in a room full of trash. The walls then start closing in and, as in the comic, the characters are not enthused about being pushed ever closer together, and seek to push back on the walls before being crushed. Here, the quote also expresses a sense of hope: since a common symptom of COVID-19 is a loss of smell, the fact that the characters are all able to smell their surroundings is a sign that the pandemic is gone.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[From left to right, Megan (sitting), Science Girl, White Hat, Ponytail, and Cueball are having a party. There are two machines on either side of the scene, moving the walls on the left and right ever-closer in. The machines have pistons which push the walls together, and their rods are more than long enough for the walls to meet in the middle and crush the group. Cueball and Megan are pressed up against the walls, trying to slow the advance. The other three characters appear anxious.]&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:I'm planning a trash-compactor-themed party for when this is all over so we can get used to standing near each other again. &lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring White Hat]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:COVID-19]]&lt;br /&gt;
[[Category:Star Wars]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205348</id>
		<title>2416: Trash Compactor Party</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205348"/>
				<updated>2021-01-26T03:44:23Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2416&lt;br /&gt;
| date      = January 26, 2021&lt;br /&gt;
| title     = Trash Compactor Party&lt;br /&gt;
| image     = trash_compactor_party.png&lt;br /&gt;
| titletext = What an incredible smell you've discovered.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a FORMER SOCIAL-DISTANCER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
Randall has gotten tired of social distancing and wants to do the exact opposite when he can. The exact opposite of social distancing would be being crushed together by some sort of compactor.&lt;br /&gt;
&lt;br /&gt;
Cueball and Megan are trying to push the walls of the trash compactor back in order to prevent it from pushing them closer to other people. The other attendees appear to be anxiously shying away from the inexorably increasing proximity of both of their neighbouring guests. This reflects the common current trend for many normal people to maintain exagerated personal space when meeting or passing other people out and about, compared with the pre-COVID era.&lt;br /&gt;
&lt;br /&gt;
Though there are a significant proportion of the population who seem to have returned being oblivious to the pandemic (or have stayed there, though it all) and eagerly socialise, often grossly breaking rules laid down to protect people, this gathering may have been mooted as a 'Covid-safe' gathering within the advice applicable to their locale (and time, as this is for &amp;quot;when it is all over&amp;quot;), and the narrowing space is perhaps even a surprise to most of them.&lt;br /&gt;
&lt;br /&gt;
The trash compactor scenario is a TV and film {{tvtropes|TheWallsAreClosingIn|trope}}. The title text references a high-profile instance of the trope from the original {{w|Star Wars (film)|''Star Wars'' film}} (later retitled ''Star Wars: Episode IV &amp;amp;mdash; A New Hope''). Han Solo utters this quip shortly after he and several other main characters bail out of a fire fight and land in a room full of trash. The walls then start closing in and, as in the comic, the characters are not enthused about being pushed ever closer together, and seek to push back on the walls before being crushed.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[From left to right, Megan (sitting), Science Girl, White Hat, Ponytail, and Cueball are having a party. There are two machines on either side of the scene, moving the walls on the left and right ever-closer in. The machines have pistons which push the walls together, and their rods are more than long enough for the walls to meet in the middle and crush the group. Cueball and Megan are pressed up against the walls, trying to slow the advance. The other three characters appear anxious.]&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:I'm planning a trash-compactor-themed party for when this is all over so we can get used to standing near each other again. &lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring White Hat]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:COVID-19]]&lt;br /&gt;
[[Category:Star Wars]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205347</id>
		<title>2416: Trash Compactor Party</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205347"/>
				<updated>2021-01-26T03:44:05Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2416&lt;br /&gt;
| date      = January 26, 2021&lt;br /&gt;
| title     = Trash Compactor Party&lt;br /&gt;
| image     = trash_compactor_party.png&lt;br /&gt;
| titletext = What an incredible smell you've discovered.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a FORMER SOCIAL-DISTANCER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
Randall has gotten tired of social distancing and wants to do the exact opposite when he can. The exact opposite of social distancing would be being crushed together by some sort of compactor.&lt;br /&gt;
&lt;br /&gt;
Cueball and Megan are trying to push the walls of the trash compactor back in order to prevent it from pushing them closer to other people. The other attendees appear to be anxiously shying away from the inexorably increasing proximity of both of their neighbouring guests. This reflects the common current trend for many normal people to maintain exagerated personal space when meeting or passing other people out and about, compared with the pre-COVID era.&lt;br /&gt;
&lt;br /&gt;
Though there are a significant proportion of the population who seem to have returned being oblivious to the pandemic (or have stayed there, though it all) and eagerly socialise, often grossly breaking rules laid down to protect people, this gathering may have been mooted as a 'Covid-safe' gathering within the advice applicable to their locale (and time, as this is for &amp;quot;when it is all over&amp;quot;), and the narrowing space is perhaps even a surprise to most of them.&lt;br /&gt;
&lt;br /&gt;
The trash compactor scenario is a TV and film {{tvtrope|TheWallsAreClosingIn|trope}}. The title text references a high-profile instance of the trope from the original {{w|Star Wars (film)|''Star Wars'' film}} (later retitled ''Star Wars: Episode IV &amp;amp;mdash; A New Hope''). Han Solo utters this quip shortly after he and several other main characters bail out of a fire fight and land in a room full of trash. The walls then start closing in and, as in the comic, the characters are not enthused about being pushed ever closer together, and seek to push back on the walls before being crushed.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[From left to right, Megan (sitting), Science Girl, White Hat, Ponytail, and Cueball are having a party. There are two machines on either side of the scene, moving the walls on the left and right ever-closer in. The machines have pistons which push the walls together, and their rods are more than long enough for the walls to meet in the middle and crush the group. Cueball and Megan are pressed up against the walls, trying to slow the advance. The other three characters appear anxious.]&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:I'm planning a trash-compactor-themed party for when this is all over so we can get used to standing near each other again. &lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring White Hat]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:COVID-19]]&lt;br /&gt;
[[Category:Star Wars]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205343</id>
		<title>2416: Trash Compactor Party</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2416:_Trash_Compactor_Party&amp;diff=205343"/>
				<updated>2021-01-26T03:21:59Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */ he said that before the walls started to close in&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2416&lt;br /&gt;
| date      = January 26, 2021&lt;br /&gt;
| title     = Trash Compactor Party&lt;br /&gt;
| image     = trash_compactor_party.png&lt;br /&gt;
| titletext = What an incredible smell you've discovered.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a FORMER SOCIAL-DISTANCER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}.&lt;br /&gt;
&lt;br /&gt;
Randall has gotten tired of social distancing and wants to do the exact opposite when he can. The exact opposite of social distancing would be being crushed together by some sort of compactor.&lt;br /&gt;
&lt;br /&gt;
Cueball and Megan are trying to push the walls of the trash compactor back in order to prevent it from pushing them closer to other people.&lt;br /&gt;
&lt;br /&gt;
The title text references a scene from ''{{w|Star Wars IV}}'' which also takes place in a trash compactor. Han Solo utters this quip shortly after they bail out of a fire fight and land in the trash. As in the comic, the characters are not enthused about being pushed ever closer together, and seek to push back on the walls before being crushed.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
:[From left to right, Megan (sitting), Science Girl, White Hat, Ponytail, and Cueball are having a party. There are two machines on either side of the scene, moving the walls on the left and right ever-closer in. The machines have pistons which push the walls together, and their rods are more than long enough for the walls to meet in the middle and crush the group. Cueball and Megan are pressed up against the walls, trying to slow the advance. The other three characters appear anxious.]&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:I'm planning a trash-compactor-themed party for when this is all over so we can get used to standing near each other again. &lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring White Hat]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:COVID-19]]&lt;br /&gt;
[[Category:Star Wars]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2414:_Solar_System_Compression_Artifacts&amp;diff=205140</id>
		<title>2414: Solar System Compression Artifacts</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2414:_Solar_System_Compression_Artifacts&amp;diff=205140"/>
				<updated>2021-01-21T13:47:33Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2414&lt;br /&gt;
| date      = January 20, 2021&lt;br /&gt;
| title     = Solar System Compression Artifacts&lt;br /&gt;
| image     = solar_system_compression_artifacts.png&lt;br /&gt;
| titletext = Most of our universe consists of dark matter rendered completely undetectable by our spacetime codec's dynamic range issues.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a MISSING PHYSICAL PHENOMENON LOST DUE TO HIGH COMPRESSION. More on the title text - Dark matter and dynamic range issues need to be explained in more detail. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
{{w|Voyager 1}} is a [[:Category:Space probes|space probe]] launched by the United States in 1977. Originally designed to study the outer planets of the {{w|Solar System}}, it is now several decades into an extended mission beyond Neptune.&lt;br /&gt;
&lt;br /&gt;
When images are compressed by a {{w|lossy compression}} format (e.g. {{w|JPEG}}), visual artifacts are created. The Voyager probe has made history for passing many milestones of our solar system. Randall here is suggesting that the probe has passed the artifacts, as if the artifacts were an actual feature of the solar system rather than a consequence of our technology. The solar system does not have compression artifacts (unless we're living in a simulation, a theme Randall has explored from time to time). However, the slightly discolored regions often created by compression could also be a metaphor for the region of space that that solar radiation prevents from being a complete vacuum. Voyager 1 has passed through numerous such boundaries, as mentioned previously in [[1189: Voyager 1]].&lt;br /&gt;
&lt;br /&gt;
Compression artifacts are often caused by large changes in coloration over a short distance, and Randall could feel that the drastic change in coloration from bright sun to dark vacuum could be creating a compression artifact around the Sun, somewhat like the Sun looking blurry due to low video quality. However, there is no definite region where solar radiation stops, only a boundary where it fades to a level lower than that of radiation from other sources. Some compression methods result in compression artifacts that behave in the same way, fading as the distance from the color boundary increases but never completely disappearing.&lt;br /&gt;
&lt;br /&gt;
The 'solar system' in the snapshot appears to be a 4-bit greyscale-plane at a more pixelated level than the image given. It can be picked out as being in 16 'banded' levels from the brightest (closest zones, within this image, to the Sun) to darkest (the furthest illustrated expanses, heading into interstellar space), with irregular or non-trivial transitional edges but no obvious or dominant dithering/speckling or 'noise'. The Voyager image (and track) is overlaid at finer resolution in the white 'line drawing' format.&lt;br /&gt;
&lt;br /&gt;
The 'apparent pixels' seem to be at a resolution of close to the order of 1AU². A rough count of the pixelation boundaries from the craft to the leftmost edge, plus an additional allowance for the likely radius of the 'sun' (or, rather, its solar wind density, or similarly represented measure) still beyond the edge, is surprisingly close to to the 150 AU or so of distance that Voyager 1 is at, currently.&lt;br /&gt;
&lt;br /&gt;
For perspective, the Earth is then ''by definition'' within/adjacent to the single lower-resolution 'pixel' that holds the Sun, and currently over on its far side. But the Sun itself is not even visible. It would be a dotted so far beyond the left boundary of the image that Neptune, at around 30 'pixels' distance, may only ''just'' be placable within the leftmost extreme of this view at its own rightmost point in its orbit. - The overlaid Voyager 'sketch' (in its more native resolution/bit-depth and antialiasing) stretches out over maybe a dozen such low-res pixels/AUs, which is equivalent to slightly more than the radius of Saturn's orbit or the entire diameter of Jupiter's!&lt;br /&gt;
&lt;br /&gt;
In the title text the mystery of the undetectable {{w|Dark Matter}}, which current mainstream physics supposes makes up most of the mass in the universe, is explained since this dark matter is rendered completely undetectable by our spacetime codec's {{w|dynamic range}} issues (thus brushing against the theme of a simulated universe).&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[Irregular bands of gray are shown, shading from a white circular segment on the bottom left side of the panel to completely black on the right. The bands have pixelated edges. A small white space probe is shown just outside the last dark gray band, in the completely black are. A dotted line starting from inside the dark gray ending at the space probe indicated that it is moving to the right out of the gray area. Close to the white area there are many bands packed closely together and with hard to define edges. But there are five gray areas clearly separated from the white, with a tendency to be elongated towards the space probes direction.]&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:Milestone: '''''Voyager''''' has passed through the streaming video compression artifacts that mark the edge of the solar system&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Space probes]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2414:_Solar_System_Compression_Artifacts&amp;diff=205139</id>
		<title>2414: Solar System Compression Artifacts</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2414:_Solar_System_Compression_Artifacts&amp;diff=205139"/>
				<updated>2021-01-21T13:42:57Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */ hoping to get at the point&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2414&lt;br /&gt;
| date      = January 20, 2021&lt;br /&gt;
| title     = Solar System Compression Artifacts&lt;br /&gt;
| image     = solar_system_compression_artifacts.png&lt;br /&gt;
| titletext = Most of our universe consists of dark matter rendered completely undetectable by our spacetime codec's dynamic range issues.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a MISSING PHYSICAL PHENOMENON LOST DUE TO HIGH COMPRESSION. More on the title text - Dark matter and dynamic range issues need to be explained in more detail. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
{{w|Voyager 1}} is a [[:Category:Space probes|space probe]] launched by the United States in 1977. Originally designed to study the outer planets of the {{w|Solar System}}, it is now several decades into an extended mission beyond Neptune.&lt;br /&gt;
&lt;br /&gt;
When images are compressed by a {{w|lossy compression}} format (e.g. {{w|JPEG}}), visual artifacts are created. The Voyager probe has made history for passing many milestones of our solar system. Randall here is suggesting that the probe has passed the artifacts, as if the artifacts were an actual feature of the solar system rather than a consequence of our technology. The solar system does not have compression artifacts (unless we're living in a simulation, a theme Randall has explored from time to time). However, the slightly discolored regions often created by compression could also be a metaphor for the region of space that that solar radiation prevents from being a complete vacuum. Voyager 1 has passed through numerous such boundaries, as mentioned previously in [[1189: Voyager 1]].&lt;br /&gt;
&lt;br /&gt;
Compression artifacts are often caused by large changes in coloration over a short distance, and Randall could feel that the drastic change in coloration from bright sun to dark vacuum could be creating a compression artifact around the Sun, somewhat like the Sun looking blurry due to low video quality. However, there is no definite region where solar radiation stops, only a boundary where it fades to a level lower than that of radiation from other sources. Some compression methods result in compression artifacts that behave in the same way, fading as the distance from the color boundary increases but never completely disappearing.&lt;br /&gt;
&lt;br /&gt;
The 'solar system' in the snapshot appears to be a 4-bit greyscale-plane at a more pixelated level than the image given. It can be picked out as being in 16 'banded' levels from the brightest (closest zones, within this image, to the Sun) to darkest (the furthest illustrated expanses, heading into interstellar space), with irregular or non-trivial transitional edges but no obvious or dominant dithering/speckling or 'noise'. The Voyager image (and track) is overlaid at finer resolution in the white 'line drawing' format.&lt;br /&gt;
&lt;br /&gt;
The 'apparent pixels' seem to be at a resolution of close to the order of 1AU². A rough count of the pixelation boundaries from the craft to the leftmost edge, plus an additional allowance for the likely radius of the 'sun' (or, rather, its solar wind density, or similarly represented measure) still beyond the edge, is surprisingly close to to the 150 AU or so of distance that Voyager 1 is at, currently.&lt;br /&gt;
&lt;br /&gt;
For perspective, the Earth is then ''by definition'' within/adjacent to the single lower-resolution 'pixel' that holds the Sun, and currently over on its far side. But the Sun itself is not even visible. It would be a dotted so far beyond the left boundary of the image that Neptune, at around 30 'pixels' distance, may only ''just'' be placable within the leftmost extreme of this view at its own rightmost point in its orbit. - The overlaid Voyager 'sketch' (in its more native resolution/bit-depth and antialiasing) stretches out over maybe a dozen such low-res pixels/AUs, which is equivalent to slightly more than the radius of Saturn's orbit or the entire diameter of Jupiter's!&lt;br /&gt;
&lt;br /&gt;
In the title text the mystery of the undetectable {{w|Dark Matter}}, which is makes up most of the mass in the universe, is explained since this dark matter is rendered completely undetectable by our spacetime codec's {{w|dynamic range}} issues.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[Irregular bands of gray are shown, shading from a white circular segment on the bottom left side of the panel to completely black on the right. The bands have pixelated edges. A small white space probe is shown just outside the last dark gray band, in the completely black are. A dotted line starting from inside the dark gray ending at the space probe indicated that it is moving to the right out of the gray area. Close to the white area there are many bands packed closely together and with hard to define edges. But there are five gray areas clearly separated from the white, with a tendency to be elongated towards the space probes direction.]&lt;br /&gt;
&lt;br /&gt;
:[Caption below the panel:]&lt;br /&gt;
:Milestone: '''''Voyager''''' has passed through the streaming video compression artifacts that mark the edge of the solar system&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Space probes]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2413:_Pulsar_Analogy&amp;diff=205068</id>
		<title>2413: Pulsar Analogy</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2413:_Pulsar_Analogy&amp;diff=205068"/>
				<updated>2021-01-20T19:24:36Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2413&lt;br /&gt;
| date      = January 18, 2021&lt;br /&gt;
| title     = Pulsar Analogy&lt;br /&gt;
| image     = pulsar_analogy.png&lt;br /&gt;
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an INJURED ASTRONOMER - more on the injury part in the explanation. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
{{w|Pulsar}}s are dead stellar cores that produce fast-spinning beams of radiation. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude.  However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.&lt;br /&gt;
&lt;br /&gt;
Further elaborations of the analogy, rather than clarifying matters, are successively more surreal.  More misleading than the tape-measure is the idea of a laser measure being &amp;quot;exactly&amp;quot; like the emissions of a pulsar, which, although both pulse (and for the same reason), are produced in entirely different ways and are at best simply helping the mind hold the concept.&lt;br /&gt;
&lt;br /&gt;
When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its axis of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.&lt;br /&gt;
&lt;br /&gt;
Some tape measures have a built-in {{w|laser line level}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of the magnetic field.  The pulsing nature of a pulsar comes from when the axis of rotation is not precisely aligned with the axis of the magnetic field.&lt;br /&gt;
&lt;br /&gt;
The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In a left-handed coordinate system, the Y-axis instead points clockwise. Attempting to use the right hand here to calculate a {{w|cross product}} will require a 90° backward bend of the middle finger or thumb, which hurts.{{Citation needed}}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[Cueball and Ponytail are standing next to each other.]&lt;br /&gt;
:Cueball: Why do pulsars spin so ''fast?''&lt;br /&gt;
:Ponytail: Hmm, let me think of an analogy...&lt;br /&gt;
&lt;br /&gt;
:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]&lt;br /&gt;
:Retracting tape measure: ''zzzzzzzzzzzzzzz''&lt;br /&gt;
:Spinning tape measure: SNAP&lt;br /&gt;
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?&lt;br /&gt;
:Ponytail: It's like that.&lt;br /&gt;
:Cueball (off-panel): Oh, I see.&lt;br /&gt;
&lt;br /&gt;
:[A tape measure with a laser instead of a measuring tape is spinning slowly.]&lt;br /&gt;
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?&lt;br /&gt;
:Ponytail (off-panel): Exactly!&lt;br /&gt;
&lt;br /&gt;
:[Cueball and Ponytail are walking next to each other in silhouette.]&lt;br /&gt;
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.&lt;br /&gt;
:Cueball: Sounds painful!&lt;br /&gt;
:Ponytail: Top cause of astronomer hand injuries.&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Astronomy]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2413:_Pulsar_Analogy&amp;diff=205066</id>
		<title>2413: Pulsar Analogy</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2413:_Pulsar_Analogy&amp;diff=205066"/>
				<updated>2021-01-20T19:07:27Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2413&lt;br /&gt;
| date      = January 18, 2021&lt;br /&gt;
| title     = Pulsar Analogy&lt;br /&gt;
| image     = pulsar_analogy.png&lt;br /&gt;
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an INJURED ASTRONOMER - more on the injury part in the explanation. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
{{w|Pulsar}}s are dead stellar cores that produce fast-spinning beams of radiation. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. Since the analogy does result in something that spins, the reader might think that, while they don't immediately see how it helps in understanding pulsars, they're willing to reserve judgment to see what is then done with the analogy; Cueball's response may suggest this sort of wait-and-see attitude.  However, the analogy is likely to be useless or misleading, as the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.&lt;br /&gt;
&lt;br /&gt;
Further elaborations of the analogy, rather than clarifying matters, are successively more surreal.  More misleading than the tape-measure is the idea of a laser measure being &amp;quot;exactly&amp;quot; like the emissions of a pulsar, which, although both pulse (and for the same reason), are produced in entirely different ways and are simply helping the mind hold the concept.&lt;br /&gt;
&lt;br /&gt;
When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its axis of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.&lt;br /&gt;
&lt;br /&gt;
Some tape measures have a built-in {{w|laser line level}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of the magnetic field.  The pulsing nature of a pulsar comes from when the axis of rotation is not precisely aligned with the axis of the magnetic field.&lt;br /&gt;
&lt;br /&gt;
The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In a left-handed coordinate system, the Y-axis instead points clockwise. Attempting to use the right hand here to calculate a {{w|cross product}} will require a 90° backward bend of the middle finger or thumb, which hurts.{{Citation needed}}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[Cueball and Ponytail are standing next to each other.]&lt;br /&gt;
:Cueball: Why do pulsars spin so ''fast?''&lt;br /&gt;
:Ponytail: Hmm, let me think of an analogy...&lt;br /&gt;
&lt;br /&gt;
:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]&lt;br /&gt;
:Retracting tape measure: ''zzzzzzzzzzzzzzz''&lt;br /&gt;
:Spinning tape measure: SNAP&lt;br /&gt;
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?&lt;br /&gt;
:Ponytail: It's like that.&lt;br /&gt;
:Cueball (off-panel): Oh, I see.&lt;br /&gt;
&lt;br /&gt;
:[A tape measure with a laser instead of a measuring tape is spinning slowly.]&lt;br /&gt;
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?&lt;br /&gt;
:Ponytail (off-panel): Exactly!&lt;br /&gt;
&lt;br /&gt;
:[Cueball and Ponytail are walking next to each other in silhouette.]&lt;br /&gt;
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.&lt;br /&gt;
:Cueball: Sounds painful!&lt;br /&gt;
:Ponytail: Top cause of astronomer hand injuries.&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Astronomy]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2411:_1/10,000th_Scale_World&amp;diff=205037</id>
		<title>2411: 1/10,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2411:_1/10,000th_Scale_World&amp;diff=205037"/>
				<updated>2021-01-19T18:24:19Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2411&lt;br /&gt;
| date      = January 13, 2021&lt;br /&gt;
| title     = 1/10,000th Scale World&lt;br /&gt;
| image     = 1_10000th_scale_world.png&lt;br /&gt;
| titletext = OCEAN PLAY AREA RULES: No running, no horseplay, no megatsunamis, and no trying to pry the wreck of the Titanic off the bottom.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
This comic is part of a series continued in the subsequent comic, [[2412: 1/100,000th Scale World]] with a, by a factor of ten, smaller world.&lt;br /&gt;
&lt;br /&gt;
Models of large-scale objects (cars, airplanes, etc.) are typically produced at a given scale, given as a ratio between the original object (the first number) and the model (the second number). The same applies to maps and globes. What Randall has here, though, is neither a map nor a model but a seemingly complete copy of Earth, at a 1:10,000 scale. Various features and warnings are labeled.&lt;br /&gt;
&lt;br /&gt;
{{w|Miniature parks}}, also known as model villages, are tourist attractions around the world of a scale between 1:9 and 1:72.  For example, the finale of the movie ''{{w|Hot Fuzz}}'' features a battle amongst a miniature of the streets and buildings seen so far in the film.  Normally a miniature park would feature a representation of one geographical location rather than a geologically/technologically accurate depiction of our current planet. Whether or not Randall is aware of it, the reputed [http://www.mapascotland.org/ largest outdoor relief map in the world] is set out at a horizontal scale of 1:10,000.&lt;br /&gt;
&lt;br /&gt;
Real-world phenomena are reproduced at scale, for humorous effect. A real 1/10,000th scale &amp;quot;Earth&amp;quot; would have a diameter of less than a mile, and a surface area of around 2 square miles, the approximate dimensions of a medium-sized asteroid. On such an object, constrained by known physics, there would be no air, standing water, weather, or large magma bodies, and any sort of rough-housing would irrecoverably catapult the visitor into space.&lt;br /&gt;
&lt;br /&gt;
Normally in a miniature model most warnings try to prevent the visitors from accidentally doing something cataclysmic to the model. Likewise, the &amp;quot;ocean play area rules&amp;quot; in the title text tell visitors not to create any {{w|megatsunami}}s, which could conceivably be induced by a cannonball dive. But as digging seems to be discouraged mainly where it causes volcanoes to break out the visitors seem to be given a far greater freedom than usual.&lt;br /&gt;
&lt;br /&gt;
Visitors are also instructed not to try to pry the model of the {{w|wreck of the Titanic}} off the ocean floor.  In our world, the wreck is at a depth of 12,500 feet, which would be 1 foot and 3 inches in Randall's model world.  The Titanic was over 882 feet long, but the ship split in half as she sank, and now lies in two pieces about a third of a mile apart.  Randall's model would have two pieces about a half-inch in size separated by about two inches.  If the models are rusted and sunk in mud just like the real wreck is, trying to pry them loose would certainly damage them, but all of Randall's other rules seem to be about preventing harm to guests, not preventing damage to the model, so maybe he just doesn't want guests bending over and exerting themselves in water where they could slip, submerge their faces, and be at risk of drowning.&lt;br /&gt;
&lt;br /&gt;
Scale models, and the problems with them, was the subject of [[878: Model Rail]]. In general illustrating relative scale is a [[:Illustrations of scale|recurring subject]] on xkcd. This comic is also somewhat reminiscent of [[941: Depth Perception]]. &lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
| Watch out for airliners cruising near shoulder level&lt;br /&gt;
| Unintentional catastrophic damage to air traffic. The damage likely wouldn't be reciprocal: actual airplane speed is very similar to the speed at which a bullet is fired [https://pinchito.es/2019/high-speeds], but 1/10,000 of that is quite slow, on the order of 10 inches / 25 cm per second - which is fortunate, because the aircraft would weigh about half a milligram (1/50000 oz) or more.&lt;br /&gt;
| At this scale, the lowest airliner cruising altitude would be 3 ft or 0.9 m [https://time.com/5309905/how-high-do-planes-fly/#:~:text=Commercial%20aircraft%20typically%20fly%20between,that%20can%20present%20safety%20issues.], shoulder height for a 5-year-old [https://www.disabled-world.com/calculators-charts/height-weight-teens.php]. Scaling the height of the highest plane to ever fly [https://www.usatoday.com/story/travel/columnist/cox/2017/05/28/altitude/102185856/] puts it at 9 ft, which would put it just over the head of the tallest person who ever lived [https://www.guinnessworldrecords.com/records/hall-of-fame/robert-wadlow-tallest-man-ever]&lt;br /&gt;
|-&lt;br /&gt;
| Trip hazard: Appalachian Mountains&lt;br /&gt;
| At half a foot tall, the Appalachians could trip visitors who are not being careful.&lt;br /&gt;
| 6684 ft ≈ 0.67 ft in model world&lt;br /&gt;
|-&lt;br /&gt;
| Do not stand or climb on Mt. Everest&lt;br /&gt;
| One may destroy the model.&lt;br /&gt;
|Also, Everest appears to be rather pointy. Also still a bit steep, so visitors may fall down and hurt themselves.&lt;br /&gt;
|-&lt;br /&gt;
| Caution: Hydro-thermal vents underfoot&lt;br /&gt;
|Hydrothermal vents are extremely hot, which could cause burns to the feet of the viewers&lt;br /&gt;
|Underwater volcanoes and stuff&lt;br /&gt;
|-&lt;br /&gt;
| Children must be supervised while in the ocean, especially near trenches&lt;br /&gt;
|They might drown.&lt;br /&gt;
|The Challenger Deep is 36,200 feet below the surface; this equates to 3.62 feet in the model world, a depth which small children could conceivably drown in.&lt;br /&gt;
|-&lt;br /&gt;
| Danger: positive lightning! Do not touch cloud tops&lt;br /&gt;
| The cumulonimbus cloud is an electrocution hazard, as Megan is learning the hard way&lt;br /&gt;
| Getting too close to the positive cloud tops risks causing lightning to arc into you down to the negative ground.&lt;br /&gt;
|-&lt;br /&gt;
| Avoid hypoxia by regularly sitting to bring your lungs below the death zone&lt;br /&gt;
| The scale world even has a scale atmosphere, and visitors are cautioned to regularly sit down so they can breathe below the {{w|death zone}}, which is approximately two and a half feet above the surface.&lt;br /&gt;
| The death zone is approximately 8,000 meters above the ground, equating to 0.8 meters or 2.62 feet in the model world. There is also a what if on the subject [https://what-if.xkcd.com/64/].&lt;br /&gt;
|-&lt;br /&gt;
| Do &amp;lt;i&amp;gt;not&amp;lt;/i&amp;gt; dig near Yellowstone&lt;br /&gt;
| Digging up the {{w|Yellowstone Caldera}} could potentially reactivate the {{w|supervolcano}} there.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
| Please do not smack weather balloons&lt;br /&gt;
| Smacking balloons around can be a fun activity, mostly done by children, but it would be very unfriendly if done to weather balloons.&lt;br /&gt;
| Weather balloons can reach 20 ft in diameter before bursting, corresponding to a 0.6 mm small object at this scale.  The idea of smacking research data raises a sense of how advanced the idea of a physics-complete model of the world is, next to possible comparative banality of academic research.&lt;br /&gt;
|-&lt;br /&gt;
| Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&lt;br /&gt;
| The {{w|CN Tower}}, the {{w|Space Needle}} and the {{w|Burj Khalifa}} are much taller than they are wide, thus, &amp;quot;pointy.&amp;quot; The Burj Khalifa, the tallest of the three, would stand at 3.2 inches (8.3 cm) at this scale, making it possible to impale one's foot on it when walking&lt;br /&gt;
| [[File:Empire State Building (aerial view).jpg|right|100px|thumb|Pointy.]] This seems to be exclusively for the visitors' benefit, rather than that of the cities.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
[At the top of the image, inside the panel, a large title is floating in the air.]&lt;br /&gt;
RULES&lt;br /&gt;
&lt;br /&gt;
For visitors to my 1/10,000th scale world&lt;br /&gt;
&lt;br /&gt;
1 meter = 10 km   1 ft = 10,000 ft ~ 2 miles&lt;br /&gt;
&lt;br /&gt;
[Each of the following rules is written near a character or point of interest on the map.]&lt;br /&gt;
&lt;br /&gt;
[Two small dots with thin lines coming out of them horizontally are in the air near [[Cueball]].]&lt;br /&gt;
Watch out for airliners cruising near shoulder level&lt;br /&gt;
&lt;br /&gt;
[Small mountains are seen near the left edge of the screen, by Cueball's feet.]&lt;br /&gt;
Trip hazard: Appalachian Mountains&lt;br /&gt;
&lt;br /&gt;
[Someone is climbing on mountains reaching approximately Cueball's waist.]&lt;br /&gt;
Do not stand or climb on Mt. Everest&lt;br /&gt;
&lt;br /&gt;
[Under the water, a small bump in the ground expells bubbles.]&lt;br /&gt;
Caution: Hydro-thermal vents underfoot&lt;br /&gt;
&lt;br /&gt;
[[[Science Girl]] stands shoulder-deep in the ocean, peering down into the trench below.]&lt;br /&gt;
Children must be supervised while in the ocean, especially near trenches&lt;br /&gt;
&lt;br /&gt;
[[[Megan]]'s hand is extended, and lightning from the cloud is jumping to her hand.]&lt;br /&gt;
Danger: positive lightning! Do not touch cloud tops&lt;br /&gt;
&lt;br /&gt;
[Ponytail sits near some mountains, with a dotted line in the air stretching across her forehead.]&lt;br /&gt;
Avoid hypoxia by regularly sitting to bring your lungs below the death zone&lt;br /&gt;
&lt;br /&gt;
[A blob-shaped thing with wiggly grey texture lines drawn all over is underground.]&lt;br /&gt;
Do &amp;lt;i&amp;gt;not&amp;lt;/i&amp;gt; dig near Yellowstone&lt;br /&gt;
&lt;br /&gt;
[A second Cueball is jumping in the air, a hand reached back, in position to smack a weather balloon.]&lt;br /&gt;
Please do not smack weather balloons&lt;br /&gt;
&lt;br /&gt;
[Some very tiny vertical lines extend from the ground.]&lt;br /&gt;
Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Scale World]]&lt;br /&gt;
[[Category:Comics sharing name|1/10]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Geography]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Multiple Cueballs]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Category:Illustrations_of_scale&amp;diff=205036</id>
		<title>Category:Illustrations of scale</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Category:Illustrations_of_scale&amp;diff=205036"/>
				<updated>2021-01-19T18:20:53Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: try, try again&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;An occasional recurring theme in xkcd: comics centrally concerned with illustrating relative scale of things.&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics by topic]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=User:Pi_one&amp;diff=205027</id>
		<title>User:Pi one</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=User:Pi_one&amp;diff=205027"/>
				<updated>2021-01-19T15:48:26Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Hail and well come, friend.&lt;br /&gt;
&lt;br /&gt;
A bit about me:  I live in New England (and always have, and so far have never wanted to live anywhere else).  My only language is English, though I have snippets of knowledge about some other languages.  I do love language, and mostly-lurk on the fringes of the {{w|b:Conlang|conlanging}} community.  I contribute, unevenly (but it adds up over the years), to the '''''{{w|b:Conlang|Conlang}}''''' wikibook.  My passion is '''{{w|n:User:Pi zero|Wikinews}}'''.  I have a PhD in Computer Science, for whatever that's worth.  Oh yes, and I'm a fan of xkcd :D.&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=User:Pi_one&amp;diff=205026</id>
		<title>User:Pi one</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=User:Pi_one&amp;diff=205026"/>
				<updated>2021-01-19T15:46:24Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: something&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;Hail and well come, friend.&lt;br /&gt;
&lt;br /&gt;
A bit about me:  I live in New England (and always have, and so far have never wanted to live anywhere else).  My only language is English, though I have snippets of knowledge about some other languages.  I do love language, and I mostly-lurk on the fringes of the {{w|b:Conlang|conlanging}} community.  I contribute, unevenly (but it adds up over the years), to the '''''{{w|b:Conlang|Conlang}}''''' wikibook.  My passion is '''{{w|n:User:Pi zero|Wikinews}}'''.  I have a PhD in Computer Science, for whatever that's worth.  Oh yes, and I'm a fan of xkcd :D.&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Category:Illustrations_of_scale&amp;diff=205024</id>
		<title>Category:Illustrations of scale</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Category:Illustrations_of_scale&amp;diff=205024"/>
				<updated>2021-01-19T14:14:32Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: attempt to clarify&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;An occasional recurring theme in xkcd: comics whose main theme is is to the illustrate relative scale of things.&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics by topic]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2413:_Pulsar_Analogy&amp;diff=204990</id>
		<title>2413: Pulsar Analogy</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2413:_Pulsar_Analogy&amp;diff=204990"/>
				<updated>2021-01-19T04:08:05Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2413&lt;br /&gt;
| date      = January 18, 2021&lt;br /&gt;
| title     = Pulsar Analogy&lt;br /&gt;
| image     = pulsar_analogy.png&lt;br /&gt;
| titletext = The #2 cause of astronomer hand injuries is trying to do vector math when the second axis points off to the right.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an INJURED ASTRONOMER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
{{w|Pulsar}}s are dead stellar cores that produce fast-spinning beams of radiation. Ponytail, an astronomer in this comic, explains a pulsar's fast rotation with an analogy about a tape measure retracting. This analogy could be seen as useless or misleading, considering that the tape measure starts to rotate because the retracting tape is not moving only in a radial (in/out) direction. As a star collapses into a pulsar, its natural rotation rate is greatly amplified by its shrinking moment of inertia.&lt;br /&gt;
&lt;br /&gt;
While the analogy is misleading, so is the idea of a laser measure being &amp;quot;exactly&amp;quot; like the emissions of a pulsar, which, although both pulse (and for the same reason), are produced in entirely different ways and are simply helping the mind hold the concept.&lt;br /&gt;
&lt;br /&gt;
When a tape measure retracts, the part of the tape outside the tape measure is not going directly towards the tape measure's center but rather towards a hole in the side. This means the tape possesses some angular momentum relative to the tape measure. In addition, when the tape measure retracts, the part of the tape inside the tape measure rotates around a spool (which pulls the part of the tape outside the tape measure inside), so it also has angular momentum relative to the tape measure. When the tape is completely retracted, the tape can no longer rotate relative to the tape measure, so the entire tape measure rotates due to the conservation of angular momentum. While pulsars also rotate quickly due to the conservation of angular momentum, the exact mechanism is different. Pulsars are formed when stars collapse due to no longer performing enough fusion to produce enough heat and energy to cancel out gravity. This causes the star to contract, which causes its mass, on average, to be closer to its access of rotation, which causes the rotational inertia (also called the moment of inertia) to decrease. If the star's angular velocity stayed constant, this would cause the angular momentum to decrease, so the star's angular velocity must increase in order to offset the decrease in rotational inertia, i.e. the star (which is now a pulsar) spins faster.&lt;br /&gt;
&lt;br /&gt;
Letting the tape snap into the fully retracted position will shorten the measure's lifespan, however: If the rivets that hold the bracket at the end of the tape shear off, the tape will retract entirely inside the measured body, and will be useless.&lt;br /&gt;
&lt;br /&gt;
Some tape measures have a built-in {{w|laser line level}}. Pulsars emit electromagnetic radiation out of their magnetic poles, which is similar to a laser, but unlike the laser of a tape measure, the pulsar beam is emitted through the axis of rotation (i.e. at a right angle to the &amp;quot;tape&amp;quot;).  The pulsing nature of a pulsar does not come from its rotation, as in Ponytail's analogy, but rather its precession, which swings the axial beam towards and away from Earth.&lt;br /&gt;
&lt;br /&gt;
The title text mentions the {{w|right-hand rule}} in three-dimensional space. In a typical 3D coordinate system the Y-axis will point counterclockwise to the X-axis when looking down from the positive Z-axis. In a left-handed coordinate system, the Y-axis instead points clockwise. Attempting to use the right hand here to calculate a {{w|cross product}} will require a 90° backward bend of the middle finger, which hurts.{{Citation needed}}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[Cueball and Ponytail are standing next to each other.]&lt;br /&gt;
:Cueball: Why do pulsars spin so ''fast?''&lt;br /&gt;
:Ponytail: Hmm, let me think of an analogy...&lt;br /&gt;
&lt;br /&gt;
:[A tape measure is retracting above Ponytail's head. To the right of her head, a tape measure is spinning rapidly.]&lt;br /&gt;
:Retracting tape measure: ''zzzzzzzzzzzzzzz''&lt;br /&gt;
:Spinning tape measure: SNAP&lt;br /&gt;
:Ponytail: You know how when you retract a tape measure and let go, it leaves it spinning?&lt;br /&gt;
:Ponytail: It's like that.&lt;br /&gt;
:Cueball (off-panel): Oh, I see.&lt;br /&gt;
&lt;br /&gt;
:[A tape measure with a laser instead of a measuring tape is spinning slowly.]&lt;br /&gt;
:Cueball (off-panel): And if the tape measure is the kind with a laser level, that's the beam of radiation?&lt;br /&gt;
:Ponytail (off-panel): Exactly!&lt;br /&gt;
&lt;br /&gt;
:[Cueball and Ponytail are walking next to each other in silhouette.]&lt;br /&gt;
:Ponytail: And when the tape whips around and smacks your hand, that's the neutron degeneracy shockwave.&lt;br /&gt;
:Cueball: Sounds painful!&lt;br /&gt;
:Ponytail: Top cause of astronomer hand injuries.&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Astronomy]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204939</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204939"/>
				<updated>2021-01-18T14:54:30Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Table */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. The table needs to be filled out, and the explanation needs more work as well. More on the title text with the gas mentioned. Also Cueball's remark not mentioned yet. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the previous one, [[2411: 1/10,000th Scale World]], with a 10 times larger scale (thus, a 10 times smaller world). As in the previous comic, [[Randall]] has another seemingly complete copy of Earth, this time at a 1:100,000 scale, with various features and warnings labeled. Again, real-world phenomena are replicated at scale.&lt;br /&gt;
&lt;br /&gt;
Details on the various remarks are in the [[#Table|table]] below.&lt;br /&gt;
&lt;br /&gt;
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, which spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees. What's more, the note that they haven't invented artificial gravity reveals that the scale worlds are nothing more than a mundane model, rather than some supernatural phenomenon that allows giants to roam about the surface of the Earth.&lt;br /&gt;
&lt;br /&gt;
===Table===&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
|Our aurora are probably non-toxic but please stop trying to taste them&lt;br /&gt;
| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.&lt;br /&gt;
| The plural of &amp;quot;{{w|aurora}}&amp;quot; should actually be &amp;quot;auroras&amp;quot; or &amp;quot;aurorae&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
|No breaking off pieces of the ice caps to put in your drink&lt;br /&gt;
|An ice cap is a mass of ice that covers less than 50,000 km2 (19,000 sq mi) of land area.&lt;br /&gt;
|Breaking off pieces of ice caps would affect the climate of the scale world. In addition, breaking off pieces of somebody's models is ''very'' rude.&lt;br /&gt;
|-&lt;br /&gt;
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars&lt;br /&gt;
| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up.&lt;br /&gt;
|The ionosphere would be at around 48-965 centimeters in the scale world, so visitors would need to place their phones below it to receive cellphone signals.&lt;br /&gt;
|-&lt;br /&gt;
|Do not step on Mt. Everest&lt;br /&gt;
| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale.&lt;br /&gt;
|Mt. Everest would probably be extremely sharp and puncture your foot.&lt;br /&gt;
|-&lt;br /&gt;
|Caution! Ocean floor slippery when wet&lt;br /&gt;
| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Wear sunscreen; the ozone layer only protects you below the knees.&lt;br /&gt;
|The ozone layer is a layer of the Earth's stratosphere that shields the Earth from the Sun's ultraviolet rays.&lt;br /&gt;
|The ozone layer is approximately 15-35 kilometers above Earth, or 15-35 centimeters in this scaled world, below knee height. Visitors would need sunscreen to protect them from UV rays.  In the real world, most humans live with their bodies entirely below the ozone layer{{Citation needed}} but wear sunscreen anyway, so visitors should probably also wear sunscreen below their knees as well as above if they're going to be visiting around midday.&lt;br /&gt;
|-&lt;br /&gt;
|Beware of chest-level meteors&lt;br /&gt;
|Meteors typically occur (i.e. become more visible than in space) in the mesosphere at altitudes from 76 to 100 km (250,000 to 330,000 ft).&lt;br /&gt;
|In the scale world, meteors would occur at 76 to 100 centimeters, around chest height. You'd expect head-level asteroids too, as precursors, but this may be (mutually) covered by the eye-protection against satellite re-entry, below. (A hard-hat would also be suggested.)&lt;br /&gt;
|-&lt;br /&gt;
| -100° mesopause vest recommended&lt;br /&gt;
|The mesopause is the boundary in the earth's atmosphere between the mesosphere and the thermosphere. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, it is the coldest region on Earth with temperatures as low as -100 °C (-148 °F).&lt;br /&gt;
|Without protection, visitors would succumb to hypothermia due to the extremely low temperatures.&lt;br /&gt;
|-&lt;br /&gt;
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass&lt;br /&gt;
|Five ounces, times 100,000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of {{w|Lake Tahoe}}; the {{w|Dead Sea}} is recently about 115 cubic kilometers, though it used to be somewhat larger.&lt;br /&gt;
|Five fluid ounces (US customary) is a tad below 148 cubic centimetres, or millilitres. (Elsewhere, if used, it is actually nearer 142cc.) Modern wine glasses may actually hold 450ml (filled to the brim), but 150ml is typical of a late 19thC antique glass or a modern 'serving' level that is more tasteful/economic than an overgenerous 'drown your sorrows' one.&lt;br /&gt;
|-&lt;br /&gt;
|Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
|It is at approximately head height in this model that de-orbiting spacecraft are at their fastest, depending upon where their decayed or departed original was. At scale, they'd probably equate to a metalworking fragment, perhaps more dangerous in quantity than individually.&lt;br /&gt;
|We also tend to know about satellites and fairings returning to Earth and most (unless intended to) won't significantly survive. Meteors (see above) are hard to spot in space unless particularly big, may only be detected when spotted burning up, may be significantly denser/less fragile, and could be traveling five times faster. General head protection may be advised, just in case.&lt;br /&gt;
|-&lt;br /&gt;
|Do not anger the sprites&lt;br /&gt;
| {{w|Sprite (lightning)|Sprites}} are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.&lt;br /&gt;
| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behavior. In some fairy tales, a warning would be given to not anger the spirits in case of grave repercussions.&lt;br /&gt;
|-&lt;br /&gt;
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.&lt;br /&gt;
|Short for the {{w|Mohorovičić discontinuity}}, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.&lt;br /&gt;
|Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun {{Citation needed}}. The lava has a decent chance to burn through a mop or some other tool, so it would be pretty tricky to clean up as well since your cleaning items would light on fire unless soaked in water or something.&lt;br /&gt;
|-&lt;br /&gt;
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!&lt;br /&gt;
| The {{w|International Space Station}} is the largest human-made object in space and orbits the Earth once every 90 minutes.&lt;br /&gt;
| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic, except instead of a rule preventing people from doing so, this time the visitor is being ''dared'' to attempt it, similarly to a {{w|carnival game}}.  Hitting the ISS with a nerf dart in this scaled world would have a potentially devastating effect on the ISS; however, at this scale the ISS would be about a millimeter across, so that hitting it so far above your head as it goes by would be very difficult. Rather like a target in a typical carnival-game, the scale ISS is moving past at a moderate speed, about three inches per second (7.7 cm/s), so you can have several attempts before it's entirely out of range till its next orbit.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:RULES:&lt;br /&gt;
:For visitors to my 1/100,000th scale world&lt;br /&gt;
:1 meter = 100 km, 1 ft=100,000ft≈20 miles&lt;br /&gt;
&lt;br /&gt;
:ISS (14 feet up)&lt;br /&gt;
:Returns every 90 minutes&lt;br /&gt;
:Hit it with a Nerf dart to win a prize!&lt;br /&gt;
&lt;br /&gt;
:Our aurora are probably non-toxic, but please stop trying to taste them&lt;br /&gt;
&lt;br /&gt;
:[one cell bar] Warning: Limited cell network coverage above the ionosphere. Crouch down to get more bars&lt;br /&gt;
&lt;br /&gt;
:Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
:Cueball: OW!&lt;br /&gt;
:(off-screen): What?&lt;br /&gt;
:Cueball: I got a Soyuz in my eye&lt;br /&gt;
&lt;br /&gt;
:Beware of chest level meteors&lt;br /&gt;
&lt;br /&gt;
:-100°C Mesopause vest recommended&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Scale World]]&lt;br /&gt;
[[Category:Comics sharing name|1/10]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Geography]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Space]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Multiple Cueballs]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204887</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204887"/>
				<updated>2021-01-17T19:22:39Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: er&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. The table needs to be filled out, and the explanation needs more work as well. More on the title text with the gas mentioned. Also Cueball's remark not mentioned yet. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the previous one, [[2411: 1/10,000th Scale World]], with a 10 times larger scale (thus, a 10 times smaller world). As in the previous comic, [[Randall]] has another seemingly complete copy of Earth, this time at a 1:100,000 scale, with various features and warnings labeled. Again, real-world phenomena are replicated at scale.&lt;br /&gt;
&lt;br /&gt;
Details on the various remarks are in the [[#Table|table]] below.&lt;br /&gt;
&lt;br /&gt;
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, which spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees. What's more, the note that they haven't invented artificial gravity reveals that the scale worlds are nothing more than a mundane model, rather than some supernatural phenomenon that allows giants to roam about the surface of the Earth.&lt;br /&gt;
&lt;br /&gt;
===Table===&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
|Our aurora are probably non-toxic but please stop trying to taste them&lt;br /&gt;
| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.&lt;br /&gt;
| The plural of &amp;quot;{{w|aurora}}&amp;quot; should actually be &amp;quot;auroras&amp;quot; or &amp;quot;aurorae&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
|No breaking off pieces of the ice caps to put in your drink&lt;br /&gt;
|An ice cap is a mass of ice that covers less than 50,000 km2 (19,000 sq mi) of land area.&lt;br /&gt;
|Breaking off pieces of ice caps would affect the climate of the scale world. In addition, breaking off pieces of somebody's models is ''very'' rude.&lt;br /&gt;
|-&lt;br /&gt;
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars&lt;br /&gt;
| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up.&lt;br /&gt;
|The ionosphere would be at around 48-965 centimeters in the scale world, so visitors would need to place their phones below it to receive cellphone signals.&lt;br /&gt;
|-&lt;br /&gt;
|Do not step on Mt. Everest&lt;br /&gt;
| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale.&lt;br /&gt;
|Mt. Everest would probably be extremely sharp and puncture your foot.&lt;br /&gt;
|-&lt;br /&gt;
|Caution! Ocean floor slippery when wet&lt;br /&gt;
| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Wear sunscreen; the ozone layer only protects you below the knees.&lt;br /&gt;
|The ozone layer is a layer of the Earth's stratosphere that shields the Earth from the Sun's ultraviolet rays.&lt;br /&gt;
|The ozone layer is approximately 15-35 kilometers above Earth, or 15-35 centimeters in this scaled world, below knee height. Visitors would need sunscreen to protect them from UV rays.  In the real world, most humans live with their bodies entirely below the ozone layer but wear sunscreen anyway, so visitors should probably also wear sunscreen below their knees as well as above if they're going to be visiting around midday.&lt;br /&gt;
|-&lt;br /&gt;
|Beware of chest-level meteors&lt;br /&gt;
|Meteors typically occur (i.e. become more visible than in space) in the mesosphere at altitudes from 76 to 100 km (250,000 to 330,000 ft).&lt;br /&gt;
|In the scale world, meteors would occur at 76 to 100 centimeters, around chest height. You'd expect head-level asteroids too, as precursors, but this may be (mutually) covered by the eye-protection against satellite re-entry, below. (I'd personally also suggest a hard-hat.)&lt;br /&gt;
|-&lt;br /&gt;
| -100° mesopause vest recommended&lt;br /&gt;
|The mesopause is the boundary in the earth's atmosphere between the mesosphere and the thermosphere. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, it is the coldest region on Earth with temperatures as low as -100 °C (-148 °F).&lt;br /&gt;
|Without protection, visitors would succumb to hypothermia due to the extremely low temperatures.&lt;br /&gt;
|-&lt;br /&gt;
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass&lt;br /&gt;
|Five ounces, times 100,000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of {{w|Lake Tahoe}}; the {{w|Dead Sea}} is recently about 115 cubic kilometers, though it used to be somewhat larger.&lt;br /&gt;
|Five fluid ounces (US customary) is a tad below 148 cubic centimetres, or millilitres. (Elsewhere, if used, it is actually nearer 142cc.) Modern wine glasses may actually hold 450ml (filled to the brim), but 150ml is typical of a late 19thC antique glass or a modern 'serving' level that is more tasteful/economic than an overgenerous 'drown your sorrows' one.&lt;br /&gt;
|-&lt;br /&gt;
|Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
|It is at approximately head height in this model that de-orbiting spacecraft are at their fastest, depending upon where their decayed or departed original was. At scale, they'd probably equate to a metalworking fragment, perhaps more dangerous in quantity than individually.&lt;br /&gt;
|We also tend to know about satellites and fairings returning to Earth and most (unless intended to) won't significantly survive. Meteors (see above) are hard to spot in space unless particularly big, may only be detected when spotted burning up, may be significantly denser/less fragile, and could be traveling five times faster. General head protection may be advised, just in case.&lt;br /&gt;
|-&lt;br /&gt;
|Do not anger the sprites&lt;br /&gt;
| {{w|Sprite (lightning)|Sprites}} are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.&lt;br /&gt;
| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behavior. In some fairy tales, a warning would be given to not anger the spirits in case of grave repercussions.&lt;br /&gt;
|-&lt;br /&gt;
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.&lt;br /&gt;
|Short for the {{w|Mohorovičić discontinuity}}, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.&lt;br /&gt;
|Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun {{Citation needed}}. The lava has a decent chance to burn through a mop or something, so it would be pretty tricky to clean up as well since your cleaning items would light on fire unless soaked in water or something.&lt;br /&gt;
|-&lt;br /&gt;
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!&lt;br /&gt;
| The {{w|International Space Station}} is the largest human-made object in space and orbits the Earth once every 90 minutes.&lt;br /&gt;
| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic, except instead of a rule preventing people from doing so, this time the visitor is being ''dared'' to attempt it, similarly to a {{w|carnival game}}.  Hitting the ISS with a nerf dart in this scaled world would have a potentially devastating effect on the ISS; however, at this scale the ISS would be about a millimeter across, so that hitting it so far above your head as it goes by would be very difficult.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:RULES:&lt;br /&gt;
:For visitors to my 1/100,000th scale world&lt;br /&gt;
:1 meter = 100 km, 1 ft=100,000ft≈20 miles&lt;br /&gt;
&lt;br /&gt;
:ISS (14 feet up)&lt;br /&gt;
:Returns every 90 minutes&lt;br /&gt;
:Hit it with a Nerf dart to win a prize!&lt;br /&gt;
&lt;br /&gt;
:Our aurora are probably non-toxic, but please stop trying to taste them&lt;br /&gt;
&lt;br /&gt;
:[one cell bar] Warning: Limited cell network coverage above the ionosphere. Crouch down to get more bars&lt;br /&gt;
&lt;br /&gt;
:Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
:Cueball: OW!&lt;br /&gt;
:(off-screen): What?&lt;br /&gt;
:Cueball: I got a Soyuz in my eye&lt;br /&gt;
&lt;br /&gt;
:Beware of chest level meteors&lt;br /&gt;
&lt;br /&gt;
:-100°C Mesopause vest recommended&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Scale World]]&lt;br /&gt;
[[Category:Comics sharing name|1/10]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Geography]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Space]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Multiple Cueballs]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204826</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204826"/>
				<updated>2021-01-16T22:04:17Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. The table needs to be filled out, and the explanation needs more work as well. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the [[2411: 1/10,000th Scale World|previous one]]. As in the previous comic, Randall has another seemingly complete copy of Earth, this time at a 1:100,000 scale, with various features and warnings labeled. Again, real-world phenomena are replicated at scale.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
|Our aurora are probably non-toxic but please stop trying to taste them&lt;br /&gt;
| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.&lt;br /&gt;
| The plural of &amp;quot;{{w|aurora}}&amp;quot; should actually be &amp;quot;auroras&amp;quot; or &amp;quot;aurorae&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
|No breaking off pieces of the ice caps to put in your drink&lt;br /&gt;
|An ice cap is a mass of ice that covers less than 50,000 km2 (19,000 sq mi) of land area.&lt;br /&gt;
|Breaking off pieces of ice caps would affect the climate of the scale world.&lt;br /&gt;
|-&lt;br /&gt;
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars&lt;br /&gt;
| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up.&lt;br /&gt;
|The ionosphere would be at around 48-965 centimeters in the scale world, so visitors would need to place their phones below it to receive cellphone signals.&lt;br /&gt;
|-&lt;br /&gt;
|Do not step on Mt. Everest&lt;br /&gt;
| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale.&lt;br /&gt;
|Mt. Everest would probably be extremely sharp and puncture your foot.&lt;br /&gt;
|-&lt;br /&gt;
|Caution! Ocean floor slippery when wet&lt;br /&gt;
| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Wear sunscreen; the ozone layer only protects you below the knees.&lt;br /&gt;
|The ozone layer is a layer of the Earth's stratosphere that shields the Earth from the Sun's ultraviolet rays.&lt;br /&gt;
|The ozone layer is approximately 15-35 kilometers above Earth, or 15-35 centimeters in this scaled world, below knee height. Visitors would need sunscreen to protect them from UV rays.  In the real world, most humans live with their bodies entirely below the ozone layer but wear sunscreen anyway, so visitors should probably also wear sunscreen below their knees as well as above if they're going to be visiting around midday.&lt;br /&gt;
|-&lt;br /&gt;
|Beware of chest-level meteors&lt;br /&gt;
|Meteors typically occur (i.e. become more visible than in space) in the mesosphere at altitudes from 76 to 100 km (250,000 to 330,000 ft).&lt;br /&gt;
|In the scale world, meteors would occur at 76 to 100 centimeters, around chest height. You'd expect head-level asteroids too, as precursors, but this may be (mutually) covered by the eye-protection against satellite re-entry, below. (I'd personally also suggest a hard-hat.)&lt;br /&gt;
|-&lt;br /&gt;
| -100° mesopause vest recommended&lt;br /&gt;
|The mesopause is the boundary in the earth's atmosphere between the mesosphere and the thermosphere. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, it is the coldest region on Earth with temperatures as low as -100 °C (-148 °F).&lt;br /&gt;
|Without protection, visitors would succumb to hypothermia due to the extremely low temperatures.&lt;br /&gt;
|-&lt;br /&gt;
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass&lt;br /&gt;
|Five ounces, times 100,000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of {{w|Lake Tahoe}}; the {{w|Dead Sea}} is recently about 115 cubic kilometers, though it used to be somewhat larger.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
|It is at approximately head height in this model that de-orbiting spacecraft are at their fastest, depending upon where their decayed or departed original was. At scale, they'd probably equate to a metalworking fragment, perhaps more dangerous in quantity than individually.&lt;br /&gt;
|We also tend to know about satellites and fairings returning to Earth and most (unless intended to) won't significantly survive. Meteors (see above) are hard to spot in space unless particularly big, may only be detected when spotted burning up, may be significantly denser/less fragile, and could be traveling five times faster. General head protection may be advised, just in case.&lt;br /&gt;
|-&lt;br /&gt;
|Do not anger the sprites&lt;br /&gt;
| {{w|Sprite (lightning)|Sprites}} are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.&lt;br /&gt;
| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behavior. In some fairy tales, a warning would be given to not anger the spirits in case of grave repercussions.&lt;br /&gt;
|-&lt;br /&gt;
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.&lt;br /&gt;
|Short for the {{w|Mohorovičić discontinuity}}, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.&lt;br /&gt;
|Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun {{Citation needed}}. The lava has a decent chance to burn through a mop or something, so it would be pretty tricky to clean up as well since your cleaning items would light on fire unless soaked in water or something.&lt;br /&gt;
|-&lt;br /&gt;
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!&lt;br /&gt;
| The {{w|International Space Station}} is the largest human-made object in space and orbits the Earth once every 90 minutes.&lt;br /&gt;
| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic, except instead of a rule preventing people from doing so, this time the visitor is being ''dared'' to attempt it, similarly to a {{w|carnival game}}.  Hitting the ISS with a nerf dart in this scaled world would have a potentially devastating effect on the ISS; however, at this scale the ISS would be about a millimeter across, so that hitting it so far above your head as it goes by would be very difficult.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, which spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:RULES:&lt;br /&gt;
:For visitors to my 1/100,000th scale world&lt;br /&gt;
:1 meter = 100 km, 1 ft=100,000ft≈20 miles&lt;br /&gt;
&lt;br /&gt;
:ISS (14 feet up)&lt;br /&gt;
:Returns every 90 minutes&lt;br /&gt;
:Hit it with a Nerf dart to win a prize!&lt;br /&gt;
&lt;br /&gt;
:Our aurora are probably non-toxic, but please stop trying to taste them&lt;br /&gt;
&lt;br /&gt;
:[one cell bar] Warning: Limited cell network coverage above the ionosphere. Crouch down to get more bars&lt;br /&gt;
&lt;br /&gt;
:Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
:Cueball: OW!&lt;br /&gt;
:(off-screen): What?&lt;br /&gt;
:Cueball: I got a Soyuz in my eye&lt;br /&gt;
&lt;br /&gt;
:Beware of chest level meteors&lt;br /&gt;
&lt;br /&gt;
:-100°C Mesopause vest recommended&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204825</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204825"/>
				<updated>2021-01-16T21:54:27Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. The table needs to be filled out, and the explanation needs more work as well. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the [[2411: 1/10,000th Scale World|previous one]]. As in the previous comic, Randall has another seemingly complete copy of Earth, this time at a 1:100,000 scale, with various features and warnings labeled. Again, real-world phenomena are replicated at scale.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
|Our aurora are probably non-toxic but please stop trying to taste them&lt;br /&gt;
| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.&lt;br /&gt;
| The plural of &amp;quot;{{w|aurora}}&amp;quot; should actually be &amp;quot;auroras&amp;quot; or &amp;quot;aurorae&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
|No breaking off pieces of the ice caps to put in your drink&lt;br /&gt;
|An ice cap is a mass of ice that covers less than 50,000 km2 (19,000 sq mi) of land area.&lt;br /&gt;
|Breaking off pieces of ice caps would affect the climate of the scale world.&lt;br /&gt;
|-&lt;br /&gt;
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars&lt;br /&gt;
| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up.&lt;br /&gt;
|The ionosphere would be at around 48-965 centimeters in the scale world, so visitors would need to place their phones below it to receive cellphone signals.&lt;br /&gt;
|-&lt;br /&gt;
|Do not step on Mt. Everest&lt;br /&gt;
| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale.&lt;br /&gt;
|Mt. Everest would probably be extremely sharp and puncture your foot.&lt;br /&gt;
|-&lt;br /&gt;
|Caution! Ocean floor slippery when wet&lt;br /&gt;
| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Wear sunscreen; the ozone layer only protects you below the knees.&lt;br /&gt;
|The ozone layer is a layer of the Earth's stratosphere that shields the Earth from the Sun's ultraviolet rays.&lt;br /&gt;
|The ozone layer is approximately 15-35 kilometers above Earth, or 15-35 centimeters in this scaled world, below knee height. Visitors would need sunscreen to protect them from UV rays.  In the real world, most humans live with their bodies entirely below the ozone layer but wear sunscreen anyway, so visitors should probably also wear sunscreen below their knees as well as above if they're going to be visiting around midday.&lt;br /&gt;
|-&lt;br /&gt;
|Beware of chest-level meteors&lt;br /&gt;
|Meteors typically occur (i.e. become more visible than in space) in the mesosphere at altitudes from 76 to 100 km (250,000 to 330,000 ft).&lt;br /&gt;
|In the scale world, meteors would occur at 76 to 100 centimeters, around chest height. You'd expect head-level asteroids too, as precursors, but this may be (mutually) covered by the eye-protection against satellite re-entry, below. (I'd personally also suggest a hard-hat.)&lt;br /&gt;
|-&lt;br /&gt;
| -100° mesopause vest recommended&lt;br /&gt;
|The mesopause is the boundary in the earth's atmosphere between the mesosphere and the thermosphere. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, it is the coldest region on Earth with temperatures as low as -100 °C (-148 °F).&lt;br /&gt;
|Without protection, visitors would succumb to hypothermia due to the extremely low temperatures.&lt;br /&gt;
|-&lt;br /&gt;
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass&lt;br /&gt;
|Five ounces, times 100,000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of {{w|Lake Tahoe}}; the {{w|Dead Sea}} is recently about 115 cubic kilometers, though it used to be somewhat larger.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
|It is at approximately head height in this model that de-orbiting spacecraft are at their fastest, depending upon where their decayed or departed original was. At scale, they'd probably equate to a metalworking fragment, perhaps more dangerous in quantity than individually.&lt;br /&gt;
|We also tend to know about satellites and fairings returning to Earth and most (unless intended to) won't significantly survive. Meteors (see above) are hard to spot in space unless particularly big, may only be detected when spotted burning up, may be significantly denser/less fragile, and could be traveling five times faster. General head protection may be advised, just in case.&lt;br /&gt;
|-&lt;br /&gt;
|Do not anger the sprites&lt;br /&gt;
| {{w|Sprite (lightning)|Sprites}} are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.&lt;br /&gt;
| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behavior. In some fairy tales, a warning would be given to not anger the spirits in case of grave repercussions.&lt;br /&gt;
|-&lt;br /&gt;
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.&lt;br /&gt;
|Short for the {{w|Mohorovičić discontinuity}}, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.&lt;br /&gt;
|Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun {{Citation needed}}. The lava has a decent chance to burn through a mop or something, so it would be pretty tricky to clean up as well since your cleaning items would light on fire unless soaked in water or something.&lt;br /&gt;
|-&lt;br /&gt;
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!&lt;br /&gt;
| The {{w|International Space Station}} is the largest human-made object in space and orbits the Earth once every 90 minutes.&lt;br /&gt;
| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic, except instead of a rule preventing people from doing so, this time the visitor is being ''dared'' to attempt it (though it is unclear what the &amp;quot;prize&amp;quot; mentioned in the comic is).  Hitting the ISS with a nerf dart in this scaled world would have a potentially devastating effect on the ISS.  However, at this scale the ISS would be about a millimeter across, so the point of this dare may be that hitting it so far above your head as it goes by would be very difficult.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, which spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:RULES:&lt;br /&gt;
:For visitors to my 1/100,000th scale world&lt;br /&gt;
:1 meter = 100 km, 1 ft=100,000ft≈20 miles&lt;br /&gt;
&lt;br /&gt;
:ISS (14 feet up)&lt;br /&gt;
:Returns every 90 minutes&lt;br /&gt;
:Hit it with a Nerf dart to win a prize!&lt;br /&gt;
&lt;br /&gt;
:Our aurora are probably non-toxic, but please stop trying to taste them&lt;br /&gt;
&lt;br /&gt;
:[one cell bar] Warning: Limited cell network coverage above the ionosphere. Crouch down to get more bars&lt;br /&gt;
&lt;br /&gt;
:Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
:Cueball: OW!&lt;br /&gt;
:(off-screen): What?&lt;br /&gt;
:Cueball: I got a Soyuz in my eye&lt;br /&gt;
&lt;br /&gt;
:Beware of chest level meteors&lt;br /&gt;
&lt;br /&gt;
:-100°C Mesopause vest recommended&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204815</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204815"/>
				<updated>2021-01-16T16:58:46Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. The table needs to be filled out, and the explanation needs more work as well. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the [[2411: 1/10,000th Scale World|previous one]]. As in the previous comic, Randall has another seemingly complete copy of Earth, this time at a 1:100,000 scale, with various features and warnings labeled. Again, real-world phenomena are replicated at scale.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
|Our aurora are probably non-toxic but please stop trying to taste them&lt;br /&gt;
| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.&lt;br /&gt;
| The plural of &amp;quot;{{w|aurora}}&amp;quot; should actually be &amp;quot;auroras&amp;quot; or &amp;quot;aurorae&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
|No breaking off pieces of the ice caps to put in your drink&lt;br /&gt;
|An ice cap is a mass of ice that covers less than 50,000 km2 (19,000 sq mi) of land area.&lt;br /&gt;
|Breaking off pieces of ice caps would affect the climate of the scale world.&lt;br /&gt;
|-&lt;br /&gt;
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars&lt;br /&gt;
| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up.&lt;br /&gt;
|The ionosphere would be at around 48-965 centimeters in the scale world, so visitors would need to place their phones below it to receive cellphone signals.&lt;br /&gt;
|-&lt;br /&gt;
|Do not step on Mt. Everest&lt;br /&gt;
| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Caution! Ocean floor slippery when wet&lt;br /&gt;
| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Wear sunscreen; the ozone layer only protects you below the knees.&lt;br /&gt;
|The ozone layer is a layer of the Earth's stratosphere that shields the Earth from the Sun's ultraviolet rays.&lt;br /&gt;
|The ozone layer is approximately 15-35 kilometers above Earth, or 15-35 centimeters in this scaled world, below knee height. Visitors would need sunscreen to protect them from UV rays.  In the real world, most humans live with their bodies entirely below the ozone layer but wear sunscreen anyway, so visitors should probably also wear sunscreen below their knees as well as above if they're going to be visiting around midday.&lt;br /&gt;
|-&lt;br /&gt;
|Beware of chest-level meteors&lt;br /&gt;
|Meteors typically occur (i.e. become more visible than in space) in the mesosphere at altitudes from 76 to 100 km (250,000 to 330,000 ft).&lt;br /&gt;
|In the scale world, meteors would occur at 76 to 100 centimeters, around chest height. You'd expect head-level asteroids too, as precursors, but this may be (mutually) covered by the eye-protection against satellite re-entry, below. (I'd personally also suggest a hard-hat.)&lt;br /&gt;
|-&lt;br /&gt;
| -100° mesopause vest recommended&lt;br /&gt;
|The mesopause is the boundary in the earth's atmosphere between the mesosphere and the thermosphere. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, it is the coldest region on Earth with temperatures as low as -100 °C (-148 °F).&lt;br /&gt;
|Without protection, visitors would succumb to hypothermia due to the extremely low temperatures.&lt;br /&gt;
|-&lt;br /&gt;
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass&lt;br /&gt;
|Five ounces, times 100,000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of {{w|Lake Tahoe}}; the {{w|Dead Sea}} is recently about 115 cubic kilometers, though it used to be somewhat larger.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
|It is at approximately head height in this model that de-orbiting spacecraft are at their fastest, depending upon where their decayed or departed original was. At scale, they'd probably equate to a metalworking fragment, perhaps more dangerous in quantity than individually.&lt;br /&gt;
|We also tend to know about satellites and fairings returning to Earth and most (unless intended to) won't significantly survive. Meteors (see above) are hard to spot in space unless particularly big, may only be detected when spotted burning up, may be significantly denser/less fragile, and could be traveling five times faster. General head protection may be advised, just in case.&lt;br /&gt;
|-&lt;br /&gt;
|Do not anger the sprites&lt;br /&gt;
| {{w|Sprite (lightning)|Sprites}} are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.&lt;br /&gt;
| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behavior. In some fairy tales, a warning would be given to not anger the spirits in case of grave repercussions.&lt;br /&gt;
|-&lt;br /&gt;
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.&lt;br /&gt;
|Short for the {{w|Mohorovičić discontinuity}}, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.&lt;br /&gt;
|Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun. The lava has a decent chance to burn through a mop or something, so it would be pretty tricky to clean up as well since your cleaning items would light on fire unless soaked in water or something.&lt;br /&gt;
|-&lt;br /&gt;
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!&lt;br /&gt;
| The {{w|International Space Station}} is the largest human-made object in space and orbits the Earth once every 90 minutes.&lt;br /&gt;
| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic, except instead of a rule preventing people from doing so, this time the visitor is being ''dared'' to attempt it (though it is unclear what the &amp;quot;prize&amp;quot; mentioned in the comic is).  Hitting the ISS with a nerf dart in this scaled world would have a potentially devastating effect on the ISS.  However, at this scale the ISS would be about a millimeter across, so the point of this dare may be that hitting it so far above your head as it goes by overhead would be very difficult.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, which spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:RULES:&lt;br /&gt;
:For visitors to my 1/100,000th scale world&lt;br /&gt;
:1 meter = 100 km, 1 ft=100,000ft≈20 miles&lt;br /&gt;
&lt;br /&gt;
:ISS (14 feet up)&lt;br /&gt;
:Returns every 90 minutes&lt;br /&gt;
:Hit it with a Nerf dart to win a prize!&lt;br /&gt;
&lt;br /&gt;
:Our aurora are probably non-toxic, but please stop trying to taste them&lt;br /&gt;
&lt;br /&gt;
:[one cell bar] Warning: Limited cell network coverage above the ionosphere. Crouch down to get more bars&lt;br /&gt;
&lt;br /&gt;
:Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
:Cueball: OW!&lt;br /&gt;
:(off-screen): What?&lt;br /&gt;
:Cueball: I got a Soyuz in my eye&lt;br /&gt;
&lt;br /&gt;
:Beware of chest level meteors&lt;br /&gt;
&lt;br /&gt;
:-100°C Mesopause vest recommended&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204812</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204812"/>
				<updated>2021-01-16T15:11:02Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. The table needs to be filled out, and the explanation needs more work as well. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the [[2411: 1/10,000th Scale World|previous one]]. As in the previous comic, Randall has another seemingly complete copy of Earth, this time at a 1:100,000 scale, with various features and warnings labeled. Again, real-world phenomena are replicated at scale.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
|Our aurora are probably non-toxic but please stop trying to taste them&lt;br /&gt;
| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.&lt;br /&gt;
| The plural of &amp;quot;{{w|aurora}}&amp;quot; should actually be &amp;quot;auroras&amp;quot; or &amp;quot;aurorae&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
|No breaking off pieces of the ice caps to put in your drink&lt;br /&gt;
|An ice cap is a mass of ice that covers less than 50,000 km2 (19,000 sq mi) of land area.&lt;br /&gt;
|Breaking off pieces of ice caps would affect the climate of the scale world.&lt;br /&gt;
|-&lt;br /&gt;
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars&lt;br /&gt;
| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up.&lt;br /&gt;
|The ionosphere would be at around 48-965 centimeters in the scale world, so visitors would need to place their phones below it to receive cellphone signals.&lt;br /&gt;
|-&lt;br /&gt;
|Do not step on Mt. Everest&lt;br /&gt;
| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Caution! Ocean floor slippery when wet&lt;br /&gt;
| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Wear sunscreen; the ozone layer only protects you below the knees.&lt;br /&gt;
|The ozone layer is a layer of the Earth's stratosphere that shields the earth from the sun's ultraviolet rays.&lt;br /&gt;
|The ozone layer is approximately 15-35 kilometers above Earth, or 15-35 centimeters in this scaled world, below knee height. Visitors would need sunscreen to protect them from UV rays.&lt;br /&gt;
|-&lt;br /&gt;
|Beware of chest-level meteors&lt;br /&gt;
|Meteors typically occur (i.e. become more visible than in space) in the mesosphere at altitudes from 76 to 100 km (250,000 to 330,000 ft).&lt;br /&gt;
|In the scale world, meteors would occur at 76 to 100 centimeters, around chest height. You'd expect head-level asteroids too, as precursors, but this may be (mutually) covered by the eye-protection against satellite re-entry, below. (I'd personally also suggest a hard-hat.)&lt;br /&gt;
|-&lt;br /&gt;
| -100° mesopause vest recommended&lt;br /&gt;
|The mesopause is the boundary in the earth's atmosphere between the mesosphere and the thermosphere. Due to the lack of solar heating and very strong radiative cooling from carbon dioxide, it is the coldest region on Earth with temperatures as low as -100 °C (-148 °F).&lt;br /&gt;
|Without protection, visitors would succumb to hypothermia due to the extremely low temperatures.&lt;br /&gt;
|-&lt;br /&gt;
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass&lt;br /&gt;
|Five ounces, times 100,000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of {{w|Lake Tahoe}}; the {{w|Dead Sea}} is recently about 115 cubic kilometers, though it used to be somewhat larger.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
|It is at approximately head-height, innthis model, that de-orbitting spacecraft are at their fastest, depending upon where their decayed or departed original was. At scale, they'd probably equate to a metalworking fragment, perhaps more dangerous in quantity than individually.&lt;br /&gt;
|We also tend to know about satellites and fairings returning to Earth and most (unless intended to) won't significantly survive. Meteors (see above) are hard to spot in space unless particularly big, may only be detected when spotted burning up, may be significantly denser/less fragile and could be travelling five times faster. General head protection may be advised, just in case.&lt;br /&gt;
|-&lt;br /&gt;
|Do not anger the sprites&lt;br /&gt;
| {{w|Sprite (lightning)|Sprites}} are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.&lt;br /&gt;
| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behavior. In some fairy tales, a warning would be given to not anger the spirits in case of grave repercussions.&lt;br /&gt;
|-&lt;br /&gt;
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.&lt;br /&gt;
|Short for the {{w|Mohorovičić discontinuity}}, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.&lt;br /&gt;
|Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun. The lava has a decent chance to burn through a mop or something, so it would be pretty tricky to clean up as well since your cleaning items would light on fire unless soaked in water or something.&lt;br /&gt;
|-&lt;br /&gt;
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!&lt;br /&gt;
| The {{w|International Space Station}} is the largest human-made object in space and orbits the Earth once every 90 minutes.&lt;br /&gt;
| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic, except instead of a rule preventing people from doing so, this time it is being encouraged (though it is unclear what the &amp;quot;prize&amp;quot; mentioned in the comic is). Hitting the ISS with a nerf dart in this scaled world would have a potentially devastating effect on the ISS.  However, at this scale the ISS would be about a millimeter across, so the point of this dare may be that hitting it so far above your head as it goes by overhead would be very difficult.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, which spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:RULES:&lt;br /&gt;
:For visitors to my 1/100,000th scale world&lt;br /&gt;
:1 meter = 100 km, 1 ft=100,000ft≈20 miles&lt;br /&gt;
&lt;br /&gt;
:ISS (14 feet up)&lt;br /&gt;
:Returns every 90 minutes&lt;br /&gt;
:Hit it with a Nerf dart to win a prize!&lt;br /&gt;
&lt;br /&gt;
:Our aurora are probably non-toxic, but please stop trying to taste them&lt;br /&gt;
&lt;br /&gt;
:[one cell bar] Warning: Limited cell network coverage above the ionosphere. Crouch down to get more bars&lt;br /&gt;
&lt;br /&gt;
:Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
:Cueball: OW!&lt;br /&gt;
:(off-screen): What?&lt;br /&gt;
:Cueball: I got a Soyuz in my eye&lt;br /&gt;
&lt;br /&gt;
:Beware of chest level meteors&lt;br /&gt;
&lt;br /&gt;
:-100°C Mesopause vest recommended&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204780</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204780"/>
				<updated>2021-01-16T04:15:02Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */ meh&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. Missing an explanation entirely. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the [[2411: 1/10,000th Scale World|previous one]]. There is a 1/100,000th scale world in this comic.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
|Our aurora are probably non-toxic but please stop trying to taste them&lt;br /&gt;
| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.&lt;br /&gt;
| The plural of &amp;quot;{{w|aurora}}&amp;quot; should actually be &amp;quot;auroras&amp;quot; or &amp;quot;aurorae&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
|No breaking off pieces of the ice caps to put in your drink&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars&lt;br /&gt;
| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Do not step on Mt. Everest&lt;br /&gt;
| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Caution! Ocean floor slippery when wet&lt;br /&gt;
| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Wear sunscreen; the ozone layer only protects you below the knees.&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Beware of chest-level meteors&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
| -100° mesopause vest recommended&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass&lt;br /&gt;
|Five ounces, times 100,000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of {{w|Lake Tahoe}}; the {{w|Dead Sea}} is recently about 115 cubic kilometers, though it used to be somewhat larger.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Do not anger the sprites&lt;br /&gt;
| {{w|Sprite (lightning)|Sprites}} are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.&lt;br /&gt;
| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behaviour. In some fairy tales a warning would be given to not anger the spirits in case of grave repercussions.&lt;br /&gt;
|-&lt;br /&gt;
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.&lt;br /&gt;
|Short for the {{w|Mohorovičić discontinuity}}, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.&lt;br /&gt;
|Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun. The lava has a decent chance to burn through a mop or something, so it would be pretty tricky to clean up as well, since your cleaning stuff would light on fire unless soaked in water or something.&lt;br /&gt;
|-&lt;br /&gt;
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!&lt;br /&gt;
| The {{w|International Space Station}} is the largest human-made object in space, and orbits the Earth once every 90 minutes.&lt;br /&gt;
| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, that spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
RULES:&lt;br /&gt;
Text: For visitors to my 1/100,000th scale world&lt;br /&gt;
1 meter = 100 km, 1 ft=100,000ft≈20 miles&lt;br /&gt;
&lt;br /&gt;
Text: ISS (14 feet up)&lt;br /&gt;
Returns every 90 minutes&lt;br /&gt;
Hit it with a Nerf dart to win a prize!&lt;br /&gt;
&lt;br /&gt;
Text: Our Aurora are probably non-toxic, but please stop trying to taste them&lt;br /&gt;
&lt;br /&gt;
Text: [one cell bar] Warning: Limited cell network coverage above the ionosphere. Crouch down to get more bars&lt;br /&gt;
&lt;br /&gt;
Text: Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
Cueball: OW!&lt;br /&gt;
(off-screen): What?&lt;br /&gt;
Cueball: I got a Soyuz in my eye&lt;br /&gt;
&lt;br /&gt;
Text: Beware of chest level meteors&lt;br /&gt;
&lt;br /&gt;
Text: -100°C Mesopause vest recommended&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204779</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204779"/>
				<updated>2021-01-16T04:12:28Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: /* Explanation */&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. Missing an explanation entirely. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the [[2411: 1/10,000th Scale World|previous one]]. There is a 1/100,000th scale world in this comic.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
|Our aurora are probably non-toxic but please stop trying to taste them&lt;br /&gt;
| The aurora in the image is now temptingly at head height, and presumably look a lot like cotton candy or other inviting foodstuffs.&lt;br /&gt;
| The plural of &amp;quot;{{w|aurora}}&amp;quot; should actually be &amp;quot;auroras&amp;quot; or &amp;quot;aurorae&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
|No breaking off pieces of the ice caps to put in your drink&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Warning: Limited cell network coverage above the ionosphere, crouch down to get more bars&lt;br /&gt;
| The ionosphere reflects radio signals, in this case keeping terrestrial cellular phone signals from reaching phones higher up&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Do not step on Mt. Everest&lt;br /&gt;
| Mt. Everest, the highest peak on Earth, is several inches tall at 1:100,000 scale&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Caution! Ocean floor slippery when wet&lt;br /&gt;
| Due to the smaller scale, the ocean depths would only be a few inches deep at most; this amount of liquid would cause more of a 'slippery surface' than a 'water region'.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Wear sunscreen; the ozone layer only protects you below the knees.&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Beware of chest-level meteors&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
| -100° mesopause vest recommended&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|If Lake Tahoe or the Dead Sea dries up, refill them with this 5oz wine glass&lt;br /&gt;
|Five ounces, times 100,000&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; (because this is volume, so the linear scale factor applies to each of three dimensions), would be about 150 cubic kilometers, which is the approximate volume of {{w|Lake Tahoe}}; the {{w|Dead Sea}} is recently about 110 cubic kilometers, though it used to be somewhat larger.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
|&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
|Do not anger the sprites&lt;br /&gt;
| {{w|Sprite (lightning)|Sprites}} are poorly understood electrical phenomena in the upper atmosphere. They are enormous but very short-lived.&lt;br /&gt;
| Sprites are also a name given to a form of forest spirit known for mischievous and sometimes harmful behaviour. In some fairy tales a warning would be given to not anger the spirits in case of grave repercussions.&lt;br /&gt;
|-&lt;br /&gt;
|Please stop digging through the Moho. Staff are tired of cleaning up large igneous provinces.&lt;br /&gt;
|Short for the {{w|Mohorovičić discontinuity}}, the Moho is the boundary surface separating the Earth's crust from the mantle. It can be found at a depth of 6-7 miles under the ocean bed, and about 24-30 miles under the continents.&lt;br /&gt;
|Using Randall's 1/100,000th scale world, 6-7 miles would be approximately 4 inches, while 24-30 miles would be about 16 inches, making the Moho easily accessible via digging. It would indeed create large igneous provinces, and make a big mess of lava that the staff would have to clean up, which would not be fun. The lava has a decent chance to burn through a mop or something, so it would be pretty tricky to clean up as well, since your cleaning stuff would light on fire unless soaked in water or something.&lt;br /&gt;
|-&lt;br /&gt;
|ISS (14 feet up) Returns every 90 minutes - Hit it with a nerf dart, win a prize!&lt;br /&gt;
| The {{w|International Space Station}} is the largest human-made object in space, and orbits the Earth once every 90 minutes.&lt;br /&gt;
| This idea of treating modern research as a toy is in the same general panel area as the weather balloon smacking from the previous comic.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
The title text states that the floor should be slightly curved. In fact, given that the model in the comic is about 10 meters long, it represents about 1000 km of Earth, that spans about 9 degrees of a great circle. Therefore, if the model wasn't larger than the part shown in the panel, its edges would have a very noticeable slope of 4.5 degrees.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
RULES:&lt;br /&gt;
Text: For visitors to my 1/100,000th scale world&lt;br /&gt;
1 meter = 100 km, 1 ft=100,000ft≈20 miles&lt;br /&gt;
&lt;br /&gt;
Text: ISS (14 feet up)&lt;br /&gt;
Returns every 90 minutes&lt;br /&gt;
Hit it with a Nerf dart to win a prize!&lt;br /&gt;
&lt;br /&gt;
Text: Our Aurora are probably non-toxic, but please stop trying to taste them&lt;br /&gt;
&lt;br /&gt;
Text: [one cell bar] Warning: Limited cell network coverage above the ionosphere. Crouch down to get more bars&lt;br /&gt;
&lt;br /&gt;
Text: Safety glasses required for protection from reentering spacecraft&lt;br /&gt;
Cueball: OW!&lt;br /&gt;
(off-screen): What?&lt;br /&gt;
Cueball: I got a Soyuz in my eye&lt;br /&gt;
&lt;br /&gt;
Text: Beware of chest level meteors&lt;br /&gt;
&lt;br /&gt;
Text: -100°C Mesopause vest recommended&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=1515:_Basketball_Earth&amp;diff=204730</id>
		<title>1515: Basketball Earth</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=1515:_Basketball_Earth&amp;diff=204730"/>
				<updated>2021-01-15T18:32:18Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: +cat&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 1515&lt;br /&gt;
| date      = April 22, 2015&lt;br /&gt;
| title     = Basketball Earth&lt;br /&gt;
| image     = basketball earth.png&lt;br /&gt;
| titletext = How many points do you get for dunking every basketball in existence at once?&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
In this comic [[Cueball]] is repeatedly attempting to make a size comparison between the {{w|Earth}} and the {{w|Moon}}. But he only gets to say ''If the Earth were the size of a basketball, the Moon would be-''. Then he is interrupted again and again. (See the title text of [[1074: Moon Landing]] for the same Earth comparison).&lt;br /&gt;
&lt;br /&gt;
A {{w|Basketball (ball)|basketball}} is about 25&amp;amp;nbsp;cm in diameter and from this it can be inferred that the Moon should then be less than 7&amp;amp;nbsp;cm in diameter, a typical size for other smaller balls in different sports. Cueball handily illustrates this with two &amp;quot;balls&amp;quot; of the relevant sizes. At first, you think that they just look like the Earth and the Moon. But they are invisibly suspended, and — as seems clear from the first row of panels — they are actually the real Moon and Earth shrunk to the relevant size, hence the title ''Basketball Earth''.&lt;br /&gt;
&lt;br /&gt;
This would place Cueball and his &amp;quot;friends&amp;quot; in {{w|God}}-like positions, outside Earth. Maybe they are even in a different dimension since they can stand and observe the system.&lt;br /&gt;
&lt;br /&gt;
But before Cueball can finish with this common type of comparison, he is interrupted and must begin all over again. We thus never learn what object he would have compared the Moon with. It seems, likely, however, that he would use another ball for the comparison. And the best ball to use would be a {{w|tennis ball}}. See the same sort of comparison of Earth/Moon with basketball/tennis ball in this illustrative video that asks the question: [http://blogs.discovermagazine.com/badastronomy/2011/02/24/how-far-away-is-the-moon/ How far away is the Moon?]. From this, it is also obvious that the system Cueball shows is not to scale with regard to that distance, which should be 7.37 m! This is not necessarily a mistake of the comic, since Cueball never claims that these two balls are in orbit or that they are even the real ones. He is just (in vain) trying to make a size comparison of the two. (Though perhaps further exposition and demonstration might take place after the size comparison.)&lt;br /&gt;
&lt;br /&gt;
A basketball has an average diameter of 24.6&amp;amp;nbsp;cm (9.7&amp;amp;nbsp;inches) vs. a tennis ball, which has an average diameter of 6.7&amp;amp;nbsp;cm (2.6&amp;amp;nbsp;inches). The ratio between these two diameters is 0.273, which is the same (to three digits) as the ratio given on the Wikipedia page for the Moon: ''Mean radius 1737.10&amp;amp;nbsp;km (0.273&amp;amp;nbsp;Earths)''. If he had used a {{w|Baseball (ball)|baseball}}, which is slightly larger, this would still be good enough for demonstrative purposes, as it would have been with an apple.&lt;br /&gt;
&lt;br /&gt;
It is common to describe the relationship between very large (and very small) objects by analogy to common objects on a more human scale. Here is a similar example where someone has made a comparison of the sizes of the Solar system based on a [http://www.backwoodshome.com/articles/silveira60.html Sun the size of a basketball]. And here, coming from smaller scales, is an [http://www.infoplease.com/dk/science/encyclopedia/atoms.html#ESCI024ATOMS001 example] that states the following: &amp;quot;Imagine an atom magnified to the size of a football stadium. The nucleus of the atom would be the size of a pea in the centre of the stadium.&amp;quot;&lt;br /&gt;
&lt;br /&gt;
It is almost certainly not a coincidence that this comic was released on {{w|Earth Day}}, which is celebrated annually on April 22 to demonstrate support for environmental protection. This seems to be something that [[Randall]] cares about a lot, as he has made several comics demonstrating the need for the human race to begin taking better care of our globe. See, for instance, [[1321: Cold]] and [[1379: 4.5 Degrees]].&lt;br /&gt;
&lt;br /&gt;
This comic clearly demonstrates four examples where the inhabitants of Earth did not take care of the well being of our globe, although here on a somewhat grander scale than what individuals can usually do. The typical case is that people did not do this out of bad intentions, but only because they were careless, curious, playful, or just plain stupid.&lt;br /&gt;
&lt;br /&gt;
This comic may be seen as a spiritual successor to [[445: I Am Not Good with Boomerangs]] and its follow-up, [[475: Further Boomerang Difficulties]] in depicting various failed outcomes to the same opening panel.&lt;br /&gt;
&lt;br /&gt;
===Interruptions===&lt;br /&gt;
The four interruptions are described and explained below. Each of the four attempts has its own row of four panels in the comic. It is clear from panels one and two in each row that the Basketball Earth is rotating quite fast compared to the time frame of the comic since the {{w|continents}} have moved considerably between frames. It is thus not necessarily the interrupters that have moved the Basketball Earth between frames two and three, except of course in the final interruption. &lt;br /&gt;
&lt;br /&gt;
No matter how fast it rotates or whatever happens, we always see the Basketball Earth from the same side, as seen from far above the {{w|Atlantic Ocean}}. We can see the continents of the {{w|Americas}} as well as {{w|Africa}} and sometimes part of {{w|Europe}}, all of which are the borders for this ocean.&lt;br /&gt;
&lt;br /&gt;
It seems most likely that Cueball starts all over every time, with a completely fresh and new Earth-Moon system, since they look the same regardless of the catastrophe befalling the prior Basketball Earth, and the interruptions—the second especially—would be difficult to reverse. We can thus suppose that there is still &amp;quot;normal&amp;quot; life going on for each Basketball Earth before the interruption. Most or all of this life would presumably perish for all of the last three cases.&lt;br /&gt;
&lt;br /&gt;
====Black Hat====&lt;br /&gt;
In the first interruption, [[Black Hat]] comes in and is amazed by this cool floating globe. Of course, being Black Hat, he has to prod this nice globe with a digit. But by putting his finger into one of the oceans of this &amp;quot;real&amp;quot; Basketball Earth without a second thought, he apparently generates a {{w|megatsunami}} that rolls in over an unidentified city with skyscrapers, utterly dwarfed by a breaking wave.&lt;br /&gt;
&lt;br /&gt;
This is similar to a scene in &amp;quot;{{w|Men in Black II}}&amp;quot; where K messed with a globe that actually is a small planet, and his finger becomes visible in the sky of its inhabitants.  It is also similar to a &amp;quot;Pearls before swine&amp;quot; strip where the character Pig encounters Atlas and the earth in a diner, points to where he lives, and accidentally pokes himself in the eye. It is also reminiscent of {{w|Deep Impact (film)|Deep Impact}} in which a meteor strike causes exactly such a tsunami to hit the {{w|East Coast of the United States}}. Since Black Hat puts his finger down in the Atlantic Ocean, the tsunami would hit all bordering coastlines. Since the coast seems to be an eastern coast (assuming a vantage point of South --&amp;gt; North), and because Randall lives there, the city could be {{w|New York City}} or {{w|Boston}} or one of the other large US cities on the East Coast. Of course, the wave would also affect the coastline (far into land) for all the other continents.&lt;br /&gt;
&lt;br /&gt;
====Megan====&lt;br /&gt;
The second interruption occurs when [[Megan]] arrives and pours liquid (perhaps water) from a sports {{w|water bottle}} onto the Basketball Earth, seemingly flooding its entire surface. This would cause {{w|List of flood myths|extensive flooding}}, almost certainly extinguishing all multicellular land-dwelling life. The most familiar analogous situation is from the {{w|Bible}} in the {{w|Genesis flood narrative}} about {{w|Noah's Ark}}. The deluge from Megan's bottle would also change the composition of the ocean and create enormous churn and pressure changes, with widespread or catastrophic effects even on multicellular marine life. And if it were some sort of sports drink inside...&lt;br /&gt;
&lt;br /&gt;
====Cat====&lt;br /&gt;
In the third interruption, a cat walks into the shot and then playfully attacks the Basketball Earth, rolling around like it would do with a ball of {{w|yarn}} (see real-life example in [https://www.youtube.com/watch?v=k1rTAI2aExI this video]). This also seems to be an allusion to the logo of the popular web browser Mozilla Firefox, which depicts a fox curled around the earth in a similar manner to that shown in the comic.&lt;br /&gt;
&lt;br /&gt;
The people living upon this Basketball Earth would experience cataclysmic events far greater than Blackhat's digital prodding caused, especially as the Basketball Earth is no longer suspended and was thus taken &amp;quot;out of its orbit&amp;quot; and will eventually hit the floor very hard. One way or another, that will surely cause (undepicted) disasters of tremendous magnitude.&lt;br /&gt;
&lt;br /&gt;
====Ponytail====&lt;br /&gt;
In the fourth and final interruption, [[Ponytail]] uses Basketball Earth as an actual basketball. She comes running by Cueball, grabs the Basketball Earth, probably bouncing it off the floor while {{w|Dribbling#Basketball|dribbling}} towards the {{w|Backboard (basketball)|basketball hoop}} where she actually jumps in an attempt to {{w|Slam dunk|dunk}} the Basketball Earth. This would ''not'' be good for any residents of Basketball Earth{{Citation needed}}; the combined pressure, movement, and impact damage from this simple sequence would surely kill off all complex life on Basketball Earth.&lt;br /&gt;
&lt;br /&gt;
===Title text===&lt;br /&gt;
This simile-callback is continued in the title text with the idea that &amp;quot;every basketball in existence&amp;quot; (i.e., every basketball upon the Basketball Earth, as well as the Basketball Earth itself) is counted towards the score from a single dunking. Randall may have a good estimate of how many basketballs there are, perhaps through research for some [[what if?]] question or other research, but almost certainly assumes that there are no extraterrestrial basketballs ''not'' on Basketball Earth. But there might be some question about whether the Basketball Earth's own sub-scale basketballs fall within the regulations.&lt;br /&gt;
&lt;br /&gt;
If we go by the strict rules of league Basketball, the answer would only be '''two points''', as it is illegal to have more than one basketball in play at a time.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[Cueball is standing next to a floating Basketball Earth indicating it with his left hand. The continents are clearly visible as seen from above the Atlantic Ocean. This remains the same all through the comic, except that the Basketball Earth rotates a bit from frame to frame.]&lt;br /&gt;
:Cueball: If the Earth were the size of a basketball,&lt;br /&gt;
&lt;br /&gt;
:[Cueball is now indicating, with his right hand, a small pockmarked moon (also floating), in the correct proportions (regarding size not for their distance) to the Basketball Earth, which is on his other side. Black Hat walks into the panel towards Earth.]&lt;br /&gt;
:Cueball: The Moon would be—&lt;br /&gt;
:Black Hat: Hey, cool!&lt;br /&gt;
&lt;br /&gt;
:[Black Hat is touching the Basketball Earth with a digit.]&lt;br /&gt;
:Cueball: Um.&lt;br /&gt;
&lt;br /&gt;
:[In the next scene, we see a megatsunami on the verge of crashing down onto a coastal city with skyscrapers. The A's are cut off on each side of the panels frames, i.e. they begin outside and finish outside the frame.]&lt;br /&gt;
:'''AAAAAAAA'''&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:[Back to Cueball standing with the Basketball Earth in the same position as the first panel.]&lt;br /&gt;
:Cueball: Let's try that again. If the Earth were the size of a basketball,&lt;br /&gt;
&lt;br /&gt;
:[Same situation as when Black Hat walked in, except now it is Megan that walks into the frame towards the Basketball Earth holding a sports water bottle.]&lt;br /&gt;
:Cueball: The Moon would be—&lt;br /&gt;
&lt;br /&gt;
:[Megan squirts the Basketball Earth with the liquid in her water bottle while Cueball just stands watching with the Moon behind him].&lt;br /&gt;
&lt;br /&gt;
:[Megan just walks away while Cueball stares at his &amp;quot;water&amp;quot; Basketball Earth where the continents have disappeared completely beneath the liquid.]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:[Back to Cueball standing with the Basketball Earth in the same position as the first panel.]&lt;br /&gt;
:Cueball: If the Earth were the size of a basketball,&lt;br /&gt;
&lt;br /&gt;
:[Same situation as when Black Hat walked in, except now he spots a cat coming into the frame from the left.]&lt;br /&gt;
:Cueball: The Moon— would…&lt;br /&gt;
&lt;br /&gt;
:[While Cueball watches with the Moon behind him, the cat jumps at the Basketball Earth.]&lt;br /&gt;
:Cat: Mrowl!&lt;br /&gt;
&lt;br /&gt;
:[Cueball continues to watch while the cat rolls around playing with the Basketball Earth as if it was a ball of yarn.]&lt;br /&gt;
:Cat: Rrrrr&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:[Back to Cueball standing with the Basketball Earth in the same position as the first panel.]&lt;br /&gt;
:Cueball: If the Earth were the size of a basketball,&lt;br /&gt;
&lt;br /&gt;
:[Same situation as when Black Hat walked in, except this time it is Ponytail who enters the frame at a run coming from the left.]&lt;br /&gt;
:Cueball: The Moon would, uh…&lt;br /&gt;
&lt;br /&gt;
:[While Cueball watches with the Moon behind him, Ponytail has grabbed the Basketball Earth and is dribbling it out of the frame, still running.]&lt;br /&gt;
&lt;br /&gt;
:[Zoom out from Cueball who continues to watch while Ponytail reaches a basketball hoop and jumps towards it with the Basketball Earth, obviously in an attempt to make a slam dunk.]&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Black Hat]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Basketball]]&lt;br /&gt;
[[Category:Animals]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=1389:_Surface_Area&amp;diff=204729</id>
		<title>1389: Surface Area</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=1389:_Surface_Area&amp;diff=204729"/>
				<updated>2021-01-15T18:31:49Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: +cat&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 1389&lt;br /&gt;
| date      = July 2, 2014&lt;br /&gt;
| title     = Surface Area&lt;br /&gt;
| image     = surface_area.png&lt;br /&gt;
| titletext = This isn't an informational illustration; this is a thing I think we should do. First, we'll need a gigantic spool of thread. Next, we'll need some kind of... hmm, time to head to Seattle.&lt;br /&gt;
}}&lt;br /&gt;
*A [http://xkcd.com/1389/large/ larger version] of this image can be found by clicking the image at xkcd - which can be reached easily from here as always, by clicking on the comic number above.&lt;br /&gt;
{{TOC}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
This map shows the total {{w|surface area}}s of all {{w|terrestrial planet}}s, {{w|dwarf planet}}s, {{w|natural satellite|moons}}, {{w|asteroid}}s and {{w|minor planet}}s that are larger than 100 m in the {{w|Solar System}}. They have all been represented as regions of a single massive landmass - a {{w|supercontinent}} like {{w|Pangaea}} - which is clearly surrounded by some kind of ocean.&lt;br /&gt;
===Solid Surfaces Present in Comic===&lt;br /&gt;
====Earth====&lt;br /&gt;
On the area that signifies {{w|Earth}} the {{w|continents}} are drawn using a {{w|map projection}} that keeps the scale of the continents correct. (This is something that [[Randall]] cares about as can be seen in [[977: Map Projections]]). The parts of the surface of the Earth that are covered by oceans are also included in the surface area of the Earth (i.e. the map shows the Earth's {{w|Crust (geology)|crust}}). An extra layer of 3–4&amp;amp;nbsp;km of water seems rather insignificant when comparing to the Earth's radius of 6,370&amp;amp;nbsp;km.&lt;br /&gt;
&lt;br /&gt;
====The Moon====&lt;br /&gt;
{{w|Moon|The Moon}} has been inlaid in this map next to {{w|Antarctica}} which thus makes a great comparison of how small the Moon is compared to the Earth (there is room for more than 13 lunar surfaces on the Earth). Similarly, it is clear that the planet {{w|Venus}} is almost as big as the Earth.&lt;br /&gt;
&lt;br /&gt;
This is also the general idea of the map - to give an idea about how big the Earth is and how small many of the other known planets etc. are; both compared to Earth and to each other. The map drawn on the Earth is probably there mainly as a guide to size, because none of the features that are known on some of the other objects, especially The Moon (i.e. {{w|Impact crater|craters}} and &amp;quot;{{w|Lunar mare|seas}}&amp;quot;) and on {{w|Mars}} (i.e. {{w|Olympus Mons}}), are included.&lt;br /&gt;
&lt;br /&gt;
====Other Moons, Asteroids, and Dwarf Planets====&lt;br /&gt;
The objects mentioned by name on the map are all but one amongst those that have reached {{w|hydrostatic equilibrium}} and these are all included on this {{w|List of gravitationally rounded objects of the Solar System}}.&lt;br /&gt;
&lt;br /&gt;
The one named object that is '''not''' on the above list is the asteroid {{w|4 Vesta|Vesta}}, which is included because it is the second largest object in the {{w|Asteroid belt}}. It is placed right next to the largest object in this belt, the dwarf planet {{w|Ceres (dwarf planet)|Ceres}}, which is no longer considered an asteroid. And next to these two are the rest of the asteroids in two areas (see below), which thus groups all asteroids together.&lt;br /&gt;
&lt;br /&gt;
The only object from the above list, (that qualifies for having a solid surface in hydrostatic equilibrium), '''which is not included''' is the {{w|Saturn}} moon {{w|Mimas (moon)|Mimas}}, which is also clearly the smallest object on the list.&lt;br /&gt;
&lt;br /&gt;
This moon should have been located amongst the other five smaller moons of Saturn between the Earth and {{w|Titan (moon)|Titan}} (the largest of Saturn's moons). Mimas has a surface area of 490,000&amp;amp;nbsp;km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; which is somewhat smaller than the smallest included Saturn moon {{w|Enceladus}} with a surface area of 799,000&amp;amp;nbsp;km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
Generally the moons that belong to a given planet (for those with more than one moon large enough to be included), have been clustered together. Apart from the six (not seven...) moons of Saturn to the right of Earth, the four {{w|Galilean moons}} moons of {{w|Jupiter}} are located above the Earth, the five included moons from {{w|Uranus}} is located to at the top to the far right.&lt;br /&gt;
&lt;br /&gt;
The last planet to have many moons is {{w|Neptune}}, but only {{w|Triton (moon)|Triton}} is included. This is a fairly large moon, and the only of the 14 known moons of Neptune to be on the above list. However, there is one other moon, {{w|Proteus (moon)|Proteus}} which is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. It has a length of 424&amp;amp;nbsp;km in the longest direction, and a mean radius of 210&amp;amp;nbsp;km. A rough calculation of its surface area from this mean radius gives an area of 550,000&amp;amp;nbsp;km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;, making the surface area slightly larger than Mimas. As there is an '''unlabeled area''' located right next to the other Neptune moon Triton, it is most likely that this small area '''should represent Proteus''', and that it is an error that it was not labeled.&lt;br /&gt;
&lt;br /&gt;
As this is the smallest area, the cut-off of objects could have been at 500,000&amp;amp;nbsp;km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;, as Vesta is also larger than this, which would make room for Proteus, but explain the missing Mimas.&lt;br /&gt;
&lt;br /&gt;
Two of the included objects also have moons that are large enough to be included: Earth, of course, and the dwarf planet {{w|Pluto}} with its moon {{w|Charon (moon)|Charon}}. In both cases these moons have been inlaid in the area of their mother planet.&lt;br /&gt;
&lt;br /&gt;
Whereas the moons of the {{w|gas giant}}s and the asteroids have been located above and to the right of the Earth, the planets and dwarf planets have been included below earth (along with the two moons mentioned above). {{w|Mercury (planet)|Mercury}}, Mars and Venus all touching Earth, and then below them the four {{w|Trans-Neptunian object|Trans-Neptunian}} dwarf planets - the {{w|Plutoid}}s.&lt;br /&gt;
&lt;br /&gt;
====Not Included Dwarf Planets====&lt;br /&gt;
On the list from above there are, however, also these {{w|List of gravitationally rounded objects of the Solar System#Most-likely additional dwarf planets|10 objects}} which have not been included with name on the map. These object are, however, only likely candidates for being dwarf planets (depending on whether they have reached hydrostatic equilibrium or not), and on the map they have thus been relegated to the sections without individual names. These object are thus probably grouped together (along with other relatively small objects like comets and smaller moons) in the area labeled ''Various small moons, comets, etc'', which is located at the bottom of the map between Mercury and Mars. The surface area for all of these object, when the surface area have been estimated, are larger than 1 million square kilometer, and thus larger than several of the named objects. So it is not the size that is the reason why such objects as {{w|90377 Sedna|Sedna}} and {{w|50000 Quaoar|Quaoar}} are not included with name, but probably the fact they are not investigated enough yet.&lt;br /&gt;
&lt;br /&gt;
The remaining objects in the Solar System with a solid surface are the minor planets, which on the map has been labeled as asteroids even though these objects are grouped together in several other &amp;quot;belts&amp;quot; than the Asteroid belt. Here they have been assigned to two regions at the top of the map. Above the right part of the Earth area is the area ''Asteroids (1 km+)'' which include any object not already included larger than 1&amp;amp;nbsp;km. (As these objects are no longer round it is the largest dimension, the length, that should be at least 1&amp;amp;nbsp;km long). And finally the area ''Asteroids (100&amp;amp;nbsp;m+)'' thus include any object not already included larger than 100&amp;amp;nbsp;m.&lt;br /&gt;
&lt;br /&gt;
Most of the rest of the objects that have been included in these three sections can likely be found on this {{w|List of Solar System objects by size}}.&lt;br /&gt;
====Very Small Objects====&lt;br /&gt;
Tiny objects smaller than 100&amp;amp;nbsp;m down to space dust are excluded altogether as explained in the note below the headings. This is probably because their total surface area is impossible to estimate accurately, and also because any estimate would likely be too large to fit easily into the map.&lt;br /&gt;
&lt;br /&gt;
===Non-Solar Bodies===&lt;br /&gt;
Between Earth and Titan is a tiny speck noted ''all human skin'', which is an interesting sort of solid surface. A rough estimate of the average {{w|body surface area}} and thus of the average area of all {{w|Human skin|humans skin}} can be made from these {{w|Body surface area#Average values|average values}} and from {{w|Population pyramid|population pyramids}} as this [http://populationpyramid.net/world/2015/ pyramid for 2015]. Average adults have a skin area of around 1.7-1.8&amp;amp;nbsp;m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;, but as a large part of the [https://www.census.gov/popclock/ human population] are children (with skin area down to about 0.25&amp;amp;nbsp;m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; for infants) the total average will be smaller. By extrapolating the given values an average area of about 1.6&amp;amp;nbsp;m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; can be found. This would make the area 7.2&amp;amp;nbsp;billion &amp;amp;times; 1.6&amp;amp;nbsp;m&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; ≈ 11,500&amp;amp;nbsp;km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;. This is 60 times smaller than the smallest of the labeled moons {{w|Miranda (moon)|Miranda}} (of Uranus) with a surface area of 700,000&amp;amp;nbsp;km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
===Title Text===&lt;br /&gt;
The title text jokingly claims that this comic is not actually for information, but rather is something Randall thinks we should really do – that is, to stitch all the solar system's solid surfaces together, as the sub-sub heading says. To do this, we would need a giant spool of thread and then something he has to go get in Seattle… which presumably must be the {{w|Space Needle}}, a needle-like tower in Seattle, which should then be used in this grand project.&lt;br /&gt;
&lt;br /&gt;
This could also have been a reference to the [http://articles.latimes.com/2011/nov/13/travel/la-tr-seattle-20111113 Seattle seamstresses] if it weren't for the fact that it's not.&lt;br /&gt;
&lt;br /&gt;
====Skinning Planets and Surface Areas====&lt;br /&gt;
Since the land areas are on the surfaces of spheres, this would seem impossible as it would involve lots of deformation and be particularly challenging. It will also be very gruesome when he comes to the part of collecting (and stitching) all human skin together. The inclusion of this speck on the map is, however, also there to make it clear what the real intention is with the planets. Their surface is to be &amp;quot;skinned&amp;quot; of them, as you would have to do with the humans! Then it is all these &amp;quot;planet skins&amp;quot; that should be stitched together using the space needle. This also explains the ragged edges, and why the continents keep their correct size. It would make Randall into a planetary version of {{w|The Silence of the Lambs (film)|The Silence of the Lambs}} movies character ''{{w|Buffalo Bill (character)|Buffalo Bill}}'', a serial killer who tried to make a suit out of the skin from the women he killed.&lt;br /&gt;
&lt;br /&gt;
Randall would also need quite a lot of space for the very large ocean. However, the whole supercontinent is just somewhere between 3-4 times larger than the area of the Earth. And the area of the entire image is less than 9 times the area of the earth. As the {{w|Sphere#Area|formula}} for calculation surface areas for {{w|sphere}}s (4*π*r&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;) goes with the radius (r) squared, the diameter of the planet needed for the experiment do not need to be larger than 3 times that of the earth. Although there are no objects in the Solar System with this particular size, it is still smaller than the {{w|gas giant}}s, the smallest of these have a radius of almost 4 times that of the earth. {{w|Exoplanet}}s with this range of diameters have certainly been found, however, already at {{w|Exoplanet#Super-Earths, mini-Neptunes, and gas dwarfs|1.7 times the earth radius}} most planets size to be of the {{w|Super-Earth}} type and turns in to the {{w|Gas dwarf#Gas dwarf|gas dwarf}} type of planets. So an ocean of the size needed are not easy to come by.&lt;br /&gt;
&lt;br /&gt;
As has been explained above the earth's surface is included disregarding surface water (oceans) and the same is valid for other objects with surface water, as the Saturn moon Titan which has great lakes (or even oceans) of liquid {{w|methane}} on the surface or the Jupiter moon {{w|Europa (moon)|Europa}} which is covered in a deep ocean with a thick cap of ice. (Interestingly this moon is placed on the map very near to the continent of {{w|Europe}} - maybe for easy comparison of these two areas).&lt;br /&gt;
&lt;br /&gt;
===Gas Giants===&lt;br /&gt;
The gas giants Jupiter, Saturn, Uranus, and Neptune have, however, not been included because they do not have any &amp;quot;solid surfaces&amp;quot;; even if they had a solid core (which is itself not clear), this would not comprise any &amp;quot;surface&amp;quot;. The gas giants are believed to lack any well-defined surface at all, with the gases that make them up simply becoming thinner and thinner with increasing distance from the planets' centers, eventually becoming indistinguishable from the interplanetary medium. But if they were included via some sort of surface definition, the map of this comic would become a tiny speck amongst the map of the gas giants. Similarly, the surface of the {{w|Sun}} is also not considered a solid surface but hot {{w|Plasma (physics)|plasma}}; if it were included it would reduce even a map of the gas giants to a tiny speck.&lt;br /&gt;
&lt;br /&gt;
===Other Comics===&lt;br /&gt;
The map is drawn in a similar style to the two maps of the Internet that Randall has created in the past:&lt;br /&gt;
*[[256: Online Communities]]&lt;br /&gt;
*[[802: Online Communities 2]]&lt;br /&gt;
&lt;br /&gt;
===Data table===&lt;br /&gt;
Below is a table listing the object roughly in the order they would be read of the map (the same order as in the transcript.) But they can be sorted by each of the columns.&lt;br /&gt;
&lt;br /&gt;
The data is taken when possible from the following table: {{w|List of gravitationally rounded objects of the Solar System}}, and surface area is given with three significant digits.&lt;br /&gt;
&lt;br /&gt;
For {{w|4 Vesta|Vesta}} and {{w|Proteus (moon)|Proteus}} (the most likely candidate for the unlabeled area next to Triton) the area is calculated from their mean radius (i.e. they are not spherical). See also above in the explanation, also for calculating the area of all human skin.&lt;br /&gt;
&lt;br /&gt;
The surface for a given object is also given as a ''Fraction of Earth's surface'', and from this the number of times the object could be placed on the Earth's surface is given as one divided by this fraction. For instance it can be seen that The Moon's surface can be placed more than 13 times on top of that of the Earth.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable sortable&amp;quot;&lt;br /&gt;
|+Surface area of mentioned objects&lt;br /&gt;
!Object&lt;br /&gt;
!Type&lt;br /&gt;
!Surface area (km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;)&lt;br /&gt;
!Fraction of Earth's&lt;br /&gt;
!1/Fraction&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Io (moon)|Io}}||Moon of Jupiter||data-sort-value=&amp;quot;41900000&amp;quot;| 4.19×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.082||12.2&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Callisto (moon)|Callisto}}||Moon of Jupiter||data-sort-value=&amp;quot;73000000&amp;quot;| 7.30×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.143||7.00&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Europa (moon)|Europa}}||Moon of Jupiter||data-sort-value=&amp;quot;30900000&amp;quot;| 3.09×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.061||16.4&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Ganymede (moon)|Ganymede}}||Moon of Jupiter||data-sort-value=&amp;quot;87000000&amp;quot;| 8.70×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.171||5.80&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Ceres (dwarf planet)|Ceres}}||Dwarf planet||data-sort-value=&amp;quot;2800000&amp;quot;| 2.80×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.0055||180&lt;br /&gt;
|-&lt;br /&gt;
|{{w|4 Vesta|Vesta}}||Asteroid||data-sort-value=&amp;quot;870000&amp;quot;| 8.70×10&amp;lt;sup&amp;gt;5&amp;lt;/sup&amp;gt;||0.0017||590&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Asteroids}} (1&amp;amp;nbsp;km+)||Asteroid||N/A||N/A||N/A&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Proteus (moon)|Proteus}} (not labeled)||Moon of Neptune||data-sort-value=&amp;quot;550000&amp;quot;| 5.50×10&amp;lt;sup&amp;gt;5&amp;lt;/sup&amp;gt;||0.00011||910&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Triton (moon)|Triton}}||Moon of Neptune||data-sort-value=&amp;quot;23000000&amp;quot;| 2.30×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.045||22.2&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Asteroids}} (100 m+)||Asteroid||N/A||N/A||N/A&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Oberon (moon)|Oberon}}||Moon of Uranus||data-sort-value=&amp;quot;7290000&amp;quot;| 7.29×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.014||71.4&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Miranda (moon)|Miranda}}||Moon of Uranus||data-sort-value=&amp;quot;700000&amp;quot;| 7.00×10&amp;lt;sup&amp;gt;5&amp;lt;/sup&amp;gt;||0.0014||714&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Ariel (moon)|Ariel}}||Moon of Uranus||data-sort-value=&amp;quot;4210000&amp;quot;| 4.21×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.008||125&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Umbriel (moon)|Umbriel}}||Moon of Uranus||data-sort-value=&amp;quot;4300000&amp;quot;| 4.30×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.008||125&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Titania (moon)|Titania}}||Moon of Uranus||data-sort-value=&amp;quot;7820000&amp;quot;| 7.82×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.015||66.7&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Earth}}||Planet||data-sort-value=&amp;quot;510000000&amp;quot;| 5.10×10&amp;lt;sup&amp;gt;8&amp;lt;/sup&amp;gt;||1||1&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Tethys (moon)|Tethys}}||Moon of Saturn||data-sort-value=&amp;quot;4940000&amp;quot;| 3.574×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.007||143&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Enceladus}}||Moon of Saturn||data-sort-value=&amp;quot;799000&amp;quot;| 7.99×10&amp;lt;sup&amp;gt;5&amp;lt;/sup&amp;gt;||0.0016||625&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Dione (moon)|Dione}}||Moon of Saturn||data-sort-value=&amp;quot;3970000&amp;quot;| 3.97×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.0078||128&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Iapetus (moon)|Iapetus}}||Moon of Saturn||data-sort-value=&amp;quot;6700000&amp;quot;| 6.70×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.0132||75.8&lt;br /&gt;
|-&lt;br /&gt;
|All {{w|Human skin|humans skin}}||Human organ||data-sort-value=&amp;quot;11500&amp;quot;| 1.15×10&amp;lt;sup&amp;gt;4&amp;lt;/sup&amp;gt;||0.000023||43400&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Rhea (moon)|Rhea}}||Moon of Saturn||data-sort-value=&amp;quot;7340000&amp;quot;| 7.34×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.0144||69.4&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Titan (moon)|Titan}}||Moon of Saturn||data-sort-value=&amp;quot;83000000&amp;quot;| 8.30×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.163||6.14&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Mercury (planet)|Mercury}}||Planet||data-sort-value=&amp;quot;75000000&amp;quot;| 7.50×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.147||6.80&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Moon|The Moon}}||Moon of Earth||data-sort-value=&amp;quot;37900000&amp;quot;| 3.79×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.074||13.5&lt;br /&gt;
|-&lt;br /&gt;
|Various small {{w|Natural satellite|moons}}, {{w|comet}}s, etc.||N/A||N/A||N/A||N/A&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Mars}}||Planet||data-sort-value=&amp;quot;140000000&amp;quot;| 1.40×10&amp;lt;sup&amp;gt;8&amp;lt;/sup&amp;gt;||0.2745||3.64&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Makemake (dwarf planet)|Makemake}}||Dwarf planet||data-sort-value=&amp;quot;6400000&amp;quot;| 6.40×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.013||76.8&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Haumea (dwarf planet)|Haumea}}||Dwarf planet||data-sort-value=&amp;quot;6800000&amp;quot;| 6.80×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.0133||75.2&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Eris (dwarf planet)|Eris}}||Dwarf planet||data-sort-value=&amp;quot;18000000&amp;quot;| 1.80×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.0353||28.3&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Pluto}}||Dwarf planet||data-sort-value=&amp;quot;17000000&amp;quot;| 1.70×10&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;||0.0333||30.0&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Charon (moon)|Charon}}||Moon of Pluto||data-sort-value=&amp;quot;4580000&amp;quot;| 4.58×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;||0.009||111&lt;br /&gt;
|-&lt;br /&gt;
|{{w|Venus}}||Planet||data-sort-value=&amp;quot;460000000&amp;quot;| 4.60×10&amp;lt;sup&amp;gt;8&amp;lt;/sup&amp;gt;||0.901||1.10&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[At the top of a map is a heading, with two sub headings and a note in brackets:]&lt;br /&gt;
:'''Space'''&lt;br /&gt;
:Without the space&lt;br /&gt;
:The Solar System's solid surfaces stitched together&lt;br /&gt;
:(Excluding dust and small rocks)&lt;br /&gt;
:[Below the headings there is a map with several distinct areas. Each area is labelled with a name or a description. This label is noted inside the area, except for areas that are too small; here the label is written outside and a line indicates which area the label belongs to. Only exception is the largest area, on which the contours of the Earth's continents are drawn. Surrounding the map is wavy lines to indicate that this is either an island or one big super-continent placed in an even larger ocean.]&lt;br /&gt;
:[Here below are the labels given as they appear in &amp;quot;normal&amp;quot; reading order in as read from left to right in the three main rows as will be indicated:]&lt;br /&gt;
:[Row one, above the line defined by the general top of the Earth area:]&lt;br /&gt;
:Io&lt;br /&gt;
:Callisto&lt;br /&gt;
:Europa&lt;br /&gt;
:Ganymede&lt;br /&gt;
:Ceres&lt;br /&gt;
:Vesta&lt;br /&gt;
:Asteroids (1 km+)&lt;br /&gt;
:[Here – above the Asteroids area before the Triton area - is a small unlabelled area (the only other except Earth)]&lt;br /&gt;
:Triton&lt;br /&gt;
:Asteroids (100 m+)&lt;br /&gt;
:Oberon&lt;br /&gt;
:Miranda&lt;br /&gt;
:Ariel&lt;br /&gt;
:Umbriel&lt;br /&gt;
:Titania&lt;br /&gt;
:[Row two, the unlabelled Earth area's row, but here only given those that are directly written to the right of this area:]&lt;br /&gt;
:Tethys&lt;br /&gt;
:Enceladus&lt;br /&gt;
:Dione&lt;br /&gt;
:Iapetus&lt;br /&gt;
:All human skin&lt;br /&gt;
:Rhea&lt;br /&gt;
:Titan	&lt;br /&gt;
:[Row three, all the remaining items that are mainly below the Earth area:]&lt;br /&gt;
:Mercury&lt;br /&gt;
:The Moon&lt;br /&gt;
:Various small moons, comets, etc&lt;br /&gt;
:Mars&lt;br /&gt;
:Makemake&lt;br /&gt;
:Haumea&lt;br /&gt;
:Eris&lt;br /&gt;
:Pluto&lt;br /&gt;
:Charon&lt;br /&gt;
:Venus&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:Large drawings]]&lt;br /&gt;
[[Category:Maps]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Space]]&lt;br /&gt;
[[Category:Astronomy]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=1276:_Angular_Size&amp;diff=204728</id>
		<title>1276: Angular Size</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=1276:_Angular_Size&amp;diff=204728"/>
				<updated>2021-01-15T18:30:51Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: +cat&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 1276&lt;br /&gt;
| date      = October 11, 2013&lt;br /&gt;
| title     = Angular Size&lt;br /&gt;
| image     = angular size.png&lt;br /&gt;
| titletext = If the celestial sphere were mapped to the Earth's surface, astronomy would get a LOT easier; you'd just need a magnifying glass.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
This comic is a comparison of the {{w|angular diameter|angular diameters}} (or apparent diameter) of various celestial objects at the surface of the earth relative to a vertex at the center of the Earth as diagrammed in the opening panel. The objects' scales are compared to actual objects on earth. Each size given is for the object at its closest approach to earth.&lt;br /&gt;
&lt;br /&gt;
London's {{w|M25 motorway}} is around 60&amp;amp;nbsp;km (35&amp;amp;nbsp;miles) across, a {{w|soccer field}} is about 100&amp;amp;nbsp;meters long (109&amp;amp;nbsp;yards), a {{w|Table tennis table|ping pong table}} is 274&amp;amp;nbsp;centimeters long (9&amp;amp;nbsp;feet), a {{w|laptop}} is about 35&amp;amp;nbsp;centimeters across (13.75&amp;amp;nbsp;inches), the {{w|tilde}} symbol on a keyboard is about 5&amp;amp;nbsp;millimeters long (197&amp;amp;nbsp;mils), and a cell of ''{{w|Escherichia coli|E. coli}}'' is about 2&amp;amp;nbsp;microns long (78.75&amp;amp;nbsp;millionths of an inch).&lt;br /&gt;
&lt;br /&gt;
A simple {{w|Intercept theorem|formula}} can be used to find the size on earth of a celestial object when the size of or distance to the object is known. This is done by taking the radius of the earth, multiplying by the diameter of the object, and dividing by the distance to the object from the center of the earth.&lt;br /&gt;
&lt;br /&gt;
The space objects referenced in the panels are:&lt;br /&gt;
&lt;br /&gt;
*The {{w|Sun}} and the {{w|Moon}}, and also the open cluster {{w|Messier 25}}, have approximately the same size (around 0.5&amp;amp;nbsp;degrees of arc) when seen from the Earth.&lt;br /&gt;
&lt;br /&gt;
*{{w|Mercury (planet)|Mercury}}, {{w|Venus}}, {{w|Mars}}, {{w|Jupiter}}, {{w|Saturn}}, {{w|Uranus}}, and {{w|Neptune}} are the other planets of the {{w|Solar System}}.&lt;br /&gt;
&lt;br /&gt;
*{{w|Io (moon)|Io}}, {{w|Europa (moon)|Europa}}, {{w|Ganymede (moon)|Ganymede}}, and {{w|Callisto (moon)|Callisto}} are the main moons of Jupiter; {{w|Titan (moon)|Titan}} is the largest moon of Saturn; and {{w|Triton (moon)|Triton}} is the largest moon of Neptune. {{w|Ceres (dwarf planet)|Ceres}} and {{w|Pluto}} are {{w|dwarf planet}}s.&lt;br /&gt;
&lt;br /&gt;
*{{w|Phobos (moon)|Phobos}} and {{w|Deimos (moon)|Deimos}} are the moons of Mars. {{w|Eris (dwarf planet)|Eris}} is another dwarf planet. {{w|R Doradus}} and {{w|Betelgeuse}} are giant stars, respectively around 180 and 640&amp;amp;nbsp;light-years away. R Doradus is the star with the largest apparent diameter (other than the sun, of course).&lt;br /&gt;
&lt;br /&gt;
*{{w|4942 Munroe}} is an asteroid [http://blog.xkcd.com/2013/09/30/asteroid-4942-munroe/ named] after xkcd author [[Randall]] Munroe. {{w|Proxima Centauri}}, {{W|Alpha Centauri|Alpha Centauri AB}}, {{w|Barnard's star}} and {{w|Sirius}} are nearby stars (all within 10&amp;amp;nbsp;light-years from the Sun).&lt;br /&gt;
&lt;br /&gt;
*{{w|HD 189733 b}}, {{w|Gliese 581 g}}, {{w|Gliese 667 Cc}}, {{w|82 G. Eridani#Planetary_system|HD 20794 c}}, {{w|Tau Ceti#Planets|Tau Ceti c}}, and {{w|KOI-1686.01}} are {{w|extrasolar planet}}s; the parenthetical names are references to the comic [[1253: Exoplanet Names]]. However, some of the planets' parenthetical names do not match the table in the previous comic. For example, HD 20794 c is called &amp;quot;Legoland&amp;quot; rather than &amp;quot;Moonchild&amp;quot; in [[1253: Exoplanet Names]]. The {{w|black hole}} at the center of our Galaxy is {{w|Sagittarius A*}}, a massive object containing a mass more than 4&amp;amp;nbsp;million times of our Sun.&lt;br /&gt;
&lt;br /&gt;
*{{w|Voyager 1}} and {{w|Voyager 2|2}} are space probes launched in 1977, and currently around 125 and 100&amp;amp;nbsp;{{w|astronomical unit}}s away, respectively.&lt;br /&gt;
&lt;br /&gt;
The title text states that astronomy would be much easier if the celestial sphere were mapped to the earth - like a giant {{w|globe}}. Due to the distance of the stars you would just need magnifying glass to see the areas representing distant stars instead of an expensive powerful telescope to see huge distances.&lt;br /&gt;
&lt;br /&gt;
Approximate values for the mappings to the Earth sphere (based on mean Earth radius at 6,371.0&amp;amp;nbsp;km or 3,958.8&amp;amp;nbsp;mi.):&lt;br /&gt;
{| class=&amp;quot;wikitable sortable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Panel&lt;br /&gt;
! Object&lt;br /&gt;
! Distance&lt;br /&gt;
! Diameter&lt;br /&gt;
! Size at Earth sphere&lt;br /&gt;
|-&lt;br /&gt;
| rowspan=&amp;quot;4&amp;quot;| Panel 1&lt;br /&gt;
|| {{w|Sun}}&lt;br /&gt;
|| 149,600,000&amp;amp;nbsp;km (9.296×10&amp;lt;sup&amp;gt;7&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1,392,684&amp;amp;nbsp;km (865,373.7&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 59.3&amp;amp;nbsp;km (36.8&amp;amp;nbsp;mi.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Moon}} &amp;lt;small&amp;gt;Semi-major axis&amp;lt;/small&amp;gt;&lt;br /&gt;
|| 384,399&amp;amp;nbsp;km (238,854&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3,476.28&amp;amp;nbsp;km (2,160.06&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 57.6&amp;amp;nbsp;km (35.8&amp;amp;nbsp;mi.)&lt;br /&gt;
|-&lt;br /&gt;
|| Moon &amp;lt;small&amp;gt;Perigee&amp;lt;/small&amp;gt;&lt;br /&gt;
|| 363,295&amp;amp;nbsp;km (225,741&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3,476.28&amp;amp;nbsp;km (2160.06&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 60.9&amp;amp;nbsp;km (37.8&amp;amp;nbsp;mi.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Messier 25}}&lt;br /&gt;
|| 2,100 light-years &amp;lt;br/&amp;gt; 19.867 × 10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (12.158 × 10&amp;lt;sup&amp;gt;15&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 19 light-years &amp;lt;br/&amp;gt; 179.753 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (111.693 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 57.6&amp;amp;nbsp;km (35.8&amp;amp;nbsp;mi.)&lt;br /&gt;
|-&lt;br /&gt;
| rowspan=&amp;quot;7&amp;quot;| Panel 2&lt;br /&gt;
|| {{w|Mercury (planet)|Mercury}} (closest approach}&lt;br /&gt;
|| 92 million km (57 million mi.)&lt;br /&gt;
|| 4,879.4&amp;amp;nbsp;km (3,031.9&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.34&amp;amp;nbsp;km (370&amp;amp;nbsp;yd.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Venus}} (closest approach)&lt;br /&gt;
|| 41 million km (25 million mi.)&lt;br /&gt;
|| 12,103.6&amp;amp;nbsp;km (7,520.83&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.9&amp;amp;nbsp;km (1.2&amp;amp;nbsp;mi.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Mars}} (closest approach)&lt;br /&gt;
|| 56 million km (35 million mi.)&lt;br /&gt;
|| 6,792.4&amp;amp;nbsp;km (4,220.6&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.77&amp;amp;nbsp;km (840&amp;amp;nbsp;yd.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Jupiter}}&lt;br /&gt;
|| 778,547,200&amp;amp;nbsp;km (4.8377 × 10&amp;lt;sup&amp;gt;8&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 139,822&amp;amp;nbsp;km (86,881.4&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.14&amp;amp;nbsp;km (1,250&amp;amp;nbsp;yd.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Saturn}}&lt;br /&gt;
|| 1,433,449,370&amp;amp;nbsp;km (1.5676 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 120,536&amp;amp;nbsp;km (74,897.6&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.54&amp;amp;nbsp;km (590&amp;amp;nbsp;yd.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Uranus}}&lt;br /&gt;
|| 2,876,679,082&amp;amp;nbsp;km (1.7875 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 51,118&amp;amp;nbsp;km (31,763&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.11&amp;amp;nbsp;km (120&amp;amp;nbsp;yd.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Neptune}}&lt;br /&gt;
|| 4,503,443,661&amp;amp;nbsp;km (2.7983 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 49,528&amp;amp;nbsp;km (30,775&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.07&amp;amp;nbsp;km (230&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
| rowspan=&amp;quot;8&amp;quot;| Panel 3&lt;br /&gt;
|| {{w|Io}}&lt;br /&gt;
|| 778,547,200&amp;amp;nbsp;km (483.77 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3,643&amp;amp;nbsp;km (2,264&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 29.8&amp;amp;nbsp;m (74.8&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Europa}}&lt;br /&gt;
|| 778,547,200&amp;amp;nbsp;km (483.77 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3,122&amp;amp;nbsp;km (1,940&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 25.5&amp;amp;nbsp;m (83.7&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Ganymede}}&lt;br /&gt;
|| 778,547,200&amp;amp;nbsp;km (483.77 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 5,262&amp;amp;nbsp;km (3,270&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 43.1&amp;amp;nbsp;m (141&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Callisto}}&lt;br /&gt;
|| 778,547,200&amp;amp;nbsp;km (483.77 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 4,821&amp;amp;nbsp;km (2,996&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 39.5&amp;amp;nbsp;m (130&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Titan (moon)|Titan}}&lt;br /&gt;
|| 1,433,449,370&amp;amp;nbsp;km (890.7 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 5,150&amp;amp;nbsp;km (3,200&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 22.9&amp;amp;nbsp;m (75.1&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Triton}}&lt;br /&gt;
|| 4,503,443,661&amp;amp;nbsp;km (2.7983 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 2,705.2&amp;amp;nbsp;km (1,680.9&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3.8&amp;amp;nbsp;m (12&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Ceres}} (perihelion)&lt;br /&gt;
|| 380,995,855&amp;amp;nbsp;km (236.74 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 974.6&amp;amp;nbsp;km (605.6&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 16.3&amp;amp;nbsp;m (53.5&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Pluto}} (perihelion)&lt;br /&gt;
|| 4,437,000,000&amp;amp;nbsp;km (2.757 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 2,306&amp;amp;nbsp;km (1,433&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3.3&amp;amp;nbsp;m (11&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
| rowspan=&amp;quot;6&amp;quot;| Panel 4&lt;br /&gt;
|| {{w|Phobos}}&lt;br /&gt;
|| 56 million km (35 million mi.)&lt;br /&gt;
|| 26.8 × 22.4 × 18.4&amp;amp;nbsp;km (16.7 × 13.9 × 11.4&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3.05&amp;amp;nbsp;m (10.0&amp;amp;nbsp;ft.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Deimos}}&lt;br /&gt;
|| 56 million km (35 million mi.)&lt;br /&gt;
|| 15 × 12.2 × 10.4&amp;amp;nbsp;km (9.3 × 7.58 × 6.46&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.71 m (5&amp;amp;nbsp;ft. 7&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Eris}} (perihelion)&lt;br /&gt;
|| 5.723 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (3.556 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 2,326&amp;amp;nbsp;km (1,445&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 2.59 m (8&amp;amp;nbsp;ft. 6&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| Eris (aphelion)&lt;br /&gt;
|| 14.602 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (9.0733 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 2,326&amp;amp;nbsp;km (1,445&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.01 m (3&amp;amp;nbsp;ft. 3.8&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Betelgeuse}}&lt;br /&gt;
|| 643 ± 146 light-years &amp;lt;br/&amp;gt;max. 7.464 × 10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (4.638 × 10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 950–1,200 solar radii &amp;lt;br/&amp;gt;max. 1.671 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (1.038 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.43 m (4&amp;amp;nbsp;ft. 8.3&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|R Doradus}}&lt;br /&gt;
|| 178 ± 10 light-years &amp;lt;br/&amp;gt;max. 1.778 × 10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (1.105 × 10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 370 ± 50 solar radii &amp;lt;br/&amp;gt;max. 0.515 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (320 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.85 m (6&amp;amp;nbsp;ft. 0.8&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
| rowspan=&amp;quot;6&amp;quot;| Panel 5&lt;br /&gt;
|| {{w|4942 Munroe}}&lt;br /&gt;
|| 2.2 AU (1.2 AU closest to earth, 179.4 × 10&amp;lt;sup&amp;gt;6&amp;amp;nbsp;km or 111.5 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 9–10&amp;amp;nbsp;km (5.6-6.2&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 35.5&amp;amp;nbsp;cm (14.0&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Proxima Centauri}}&lt;br /&gt;
|| 4.243 light-years &amp;lt;br/&amp;gt; 40.142 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (24.943 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.141 solar radii &amp;lt;br/&amp;gt; 0.196 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (122 × 10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3.11&amp;amp;nbsp;cm (1.22&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Barnard's Star}}&lt;br /&gt;
|| 5.980 light-years &amp;lt;br/&amp;gt; 56.574 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (32.668 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.196 solar radii &amp;lt;br/&amp;gt; 0.272 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (169×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 3.06&amp;amp;nbsp;cm (1.20&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Alpha Centauri B}}&lt;br /&gt;
|| 4.366 light-years &amp;lt;br/&amp;gt; 41.305 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (25.666 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.865 solar radii &amp;lt;br/&amp;gt; 1.204 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (748 × 10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 18.6&amp;amp;nbsp;cm (7.32&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Sirius}}&lt;br /&gt;
|| 8.6 light-years &amp;lt;br/&amp;gt; 81.362 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (50.556 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.711 solar radii &amp;lt;br/&amp;gt; 2.382 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (1.480 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 18.7&amp;amp;nbsp;cm (7.36&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Alpha Centauri A}}&lt;br /&gt;
|| 4.366 light-years &amp;lt;br/&amp;gt; 41.305 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (25.666 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.227 solar radii &amp;lt;br/&amp;gt; 1.708 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (1.061 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 26.3&amp;amp;nbsp;cm (10.4&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
| rowspan=&amp;quot;9&amp;quot;| Panel 6&lt;br /&gt;
|| {{w|HD 189733}} b&lt;br /&gt;
|| 63 light-years &amp;lt;br/&amp;gt; 596.024 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (370.352 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.138 Jupiter radii &amp;lt;br/&amp;gt; 159,117&amp;amp;nbsp;km (98,870.7&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.7&amp;amp;nbsp;mm (67 mils)&lt;br /&gt;
|-&lt;br /&gt;
|| Gliese 581 g&lt;br /&gt;
|| 20.3 light-years &amp;lt;br/&amp;gt; 192.052 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (119.336 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.3 to 2.0 Earth radii &amp;lt;br/&amp;gt; max. 25,484&amp;amp;nbsp;km (15,835&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.85&amp;amp;nbsp;mm (33 mils)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Gliese 581}} (Parent star)&lt;br /&gt;
|| 20.3 light-years &amp;lt;br/&amp;gt; 192.052 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (119.336 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.29 solar radii &amp;lt;br/&amp;gt; 201,695&amp;amp;nbsp;km (125,411&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.34&amp;amp;nbsp;cm (528 mils)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Sagittarius A*|Black hole at the center of our Galaxy}}&lt;br /&gt;
|| 25,900 light-years &amp;lt;br/&amp;gt; 245.032 × 10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (152,260 × 10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| Mass 4.31 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;lt;br/&amp;gt;12.684 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (7.8815 × 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.33&amp;amp;nbsp;mm (13 mils)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Gliese 667}} Cc&lt;br /&gt;
|| 22.7 light-years &amp;lt;br/&amp;gt; 214.757 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (133.444 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 2.0 Earth radii &amp;lt;br/&amp;gt; 25,484&amp;amp;nbsp;km (15,835&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.76&amp;amp;nbsp;mm (30 mils)&lt;br /&gt;
|-&lt;br /&gt;
|| Gliese 667 (Parent star)&lt;br /&gt;
|| 22.7 light-years &amp;lt;br/&amp;gt; 214.757 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (133.444 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.42 solar radii &amp;lt;br/&amp;gt; 584,927&amp;amp;nbsp;km (363,457&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 1.74&amp;amp;nbsp;cm (685 mils)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|HD 20794}} c (Parent star)&lt;br /&gt;
|| 20 light-years &amp;lt;br/&amp;gt; 189.214 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (117.572 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.92 solar radii &amp;lt;br/&amp;gt; 1,281,269&amp;amp;nbsp;km (796,143.6&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 4.31&amp;amp;nbsp;cm (1.70&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Tau Ceti}} C (Parent star)&lt;br /&gt;
|| 11.905 light-years &amp;lt;br/&amp;gt; 112.629 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (69.9844 × 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.793 solar radii &amp;lt;br/&amp;gt; 1,104,398&amp;amp;nbsp;km (686,241.1&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 6.25&amp;amp;nbsp;cm (2.46&amp;amp;nbsp;in.)&lt;br /&gt;
|-&lt;br /&gt;
|| {{w|Koi-1686.01}} (Parent star)&lt;br /&gt;
|| 1033.8 light-years &amp;lt;br/&amp;gt; 9.780 × 10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (6.077×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.52 solar radii &amp;lt;br/&amp;gt; 724,195&amp;amp;nbsp;km (449,994&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 0.47&amp;amp;nbsp;mm (19 mils)&lt;br /&gt;
|-&lt;br /&gt;
| Panel 7&lt;br /&gt;
|| Voyager probes&lt;br /&gt;
|| ({{w|Voyager 1}} at 126.10 AU) 18.86 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;km (11.72 × 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;amp;nbsp;mi.)&lt;br /&gt;
|| 20 meters (66&amp;amp;nbsp;ft.) (with antennas)&lt;br /&gt;
|| 6.76&amp;amp;nbsp;µm (266 × 10&amp;lt;sup&amp;gt;&amp;amp;minus;6&amp;lt;/sup&amp;gt;&amp;amp;nbsp;in.)&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:The size of the part of Earth's surface directly under various space objects&lt;br /&gt;
:[Several images are shown, of space objects of differing size and at different distances from Earth, illustrating the differing sizes of their &amp;quot;shadows&amp;quot; as mapped onto Earth's surface viewed from the center of the Earth.]&lt;br /&gt;
&lt;br /&gt;
:[The first image merely sets the stage: Earth is a full circle, with two figures — Cueball and Megan — standing on it; a small space object casts a &amp;quot;shadow&amp;quot; on Megan, while a slightly larger object, though proportionally farther away, casts just about the same size shadow next to Cueball.]&lt;br /&gt;
&lt;br /&gt;
:[The second image is a map showing London, with the Thames running through it, and a ring highway running around it labeled &amp;quot;London's M25 Orbital Freeway&amp;quot;. A grey circle is overlaid, just about the diameter of the M25; it is labeled &amp;quot;The Sun and The Moon (about the same size)&amp;quot;.]&lt;br /&gt;
&lt;br /&gt;
:[The third image has a small grey rectangle in one corner labeled &amp;quot;Soccer field&amp;quot; for comparison. The image is dominated by four large, grey circles, considerably larger than the soccer field, labeled &amp;quot;Saturn&amp;quot;, &amp;quot;Mars&amp;quot;, &amp;quot;Jupiter&amp;quot;, and &amp;quot;Venus&amp;quot;, with Mars slightly larger than Saturn, Jupiter approximately twice the diameter of Saturn, and Venus approximately three times the diameter of Saturn. Smaller circles are labeled &amp;quot;Mercury&amp;quot;, &amp;quot;Uranus&amp;quot;, and &amp;quot;Neptune&amp;quot;, with Mercury still somewhat larger than the soccer field, Uranus about its size, and Neptune slightly smaller.]&lt;br /&gt;
&lt;br /&gt;
:[The fourth image has the soccer field blown up to take up much of the view; its center circle, goal areas, and corner kick areas are visible. Labeled grey circles of various circles are again overlain: Callisto and Ganymede are about as large as one half of the field; Io, Titan, and Europa are somewhat smaller than half the field; and Ceres, Triton, and Pluto are much smaller (all three together would probably fit into the soccer field's center circle).]&lt;br /&gt;
&lt;br /&gt;
:[In the fifth image, there is a different grey rectangle, this one labeled &amp;quot;Ping Pong table&amp;quot;, with a few balls and paddles visible. An irregular ovoid labeled &amp;quot;Phobos&amp;quot; is about the size of the table, as is a circle labeled &amp;quot;R. Doradus&amp;quot;. An irregular circular shape labeled &amp;quot;Deimos&amp;quot; is about the size of half the table; a circle labeled &amp;quot;Betelgeuse&amp;quot; is a little smaller, and a circle labeled &amp;quot;Eris&amp;quot; is a little smaller, though still comfortably filling most of half of the table.]&lt;br /&gt;
&lt;br /&gt;
:[In the sixth image, a light grey image of laptop computer keyboard and screen is shown, viewed from directly above. An irregular shape labeled &amp;quot;4942 Munroe&amp;quot; is slightly larger than the laptop, while circles labeled &amp;quot;Alpha Centauri A&amp;quot;, &amp;quot;Sirius&amp;quot;, and &amp;quot;Alpha Centauri B&amp;quot; form a descending series somewhat smaller than it. Circles labeled &amp;quot;Proxima Centauri&amp;quot; and &amp;quot;Barnard's Star&amp;quot; are considerably smaller than the laptop: Proxima Centauri would fit on the trackpad, while Barnard's Star covers perhaps four keys on the keyboard.]&lt;br /&gt;
&lt;br /&gt;
:[In the seventh image we see a greatly zoomed-in shape which is identified as the &amp;quot;Tilde on laptop keyboard&amp;quot;. A circle labeled &amp;quot;HD 189733 b (permadeath)&amp;quot; is almost as large as the tilde is wide; a circle labeled &amp;quot;Tau Ceti C (giant dog planet)&amp;quot; is somewhat smaller. Circles labeled &amp;quot;Gleise 581 g (jelly-filled planet)&amp;quot;, &amp;quot;Gleise 667 C c (PILF)&amp;quot;, and &amp;quot;HD 20794 c (moonchild)&amp;quot; are all 1/2 to 1/3 as wide as the tilde is wide. A smaller circle labeled &amp;quot;Event horizon of the black hole at the center of our galaxy&amp;quot; fits comfortably within the tilde's stroke width. A very small dot off in one corner (much smaller than the tilde or anything else in the image) is labeled &amp;quot;KOI-1686.01 (emergency backup earth)&amp;quot;.]&lt;br /&gt;
&lt;br /&gt;
:[Finally, in the eighth image, the size comparison is to the grey outlines of four bacilliform bacteria labeled &amp;quot;E. coli&amp;quot;. The outlines of two interstellar probes are shown, with circular main housings and protruding instruments and antennae. They are labeled &amp;quot;Voyager 1&amp;quot; and &amp;quot;Voyager 2&amp;quot;.]&lt;br /&gt;
&lt;br /&gt;
===Trivia===&lt;br /&gt;
The exact dimensions of a {{w|Football_pitch#Pitch_boundary|professional soccer field}} are not precisely defined. In international matches they must be between 64 and 75m wide and between 100 and 110m long. Therefore soccer fields aren't well suited as a precise unit of measurement. However, they are commonly used to give people a rough understanding of an areas size. According to the angular diameter of the referenced celestial objects, Randall did his calculations using dimensions of 105m × 68m.&lt;br /&gt;
&lt;br /&gt;
The M25 is actually in the exact shape of the ancient symbol Odegra, meaning &amp;quot;hail the great beast, devourer of worlds&amp;quot; in the language of the Black Priesthood of Mu.&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Math]]&lt;br /&gt;
[[Category:Astronomy]]&lt;br /&gt;
[[Category:Exoplanets]]&lt;br /&gt;
[[Category:Soccer]]&lt;br /&gt;
[[Category:Space probes]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=681:_Gravity_Wells&amp;diff=204727</id>
		<title>681: Gravity Wells</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=681:_Gravity_Wells&amp;diff=204727"/>
				<updated>2021-01-15T18:30:06Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 681&lt;br /&gt;
| date      = December 28, 2009&lt;br /&gt;
| title     = Gravity Wells&lt;br /&gt;
| image     = gravity_wells.png&lt;br /&gt;
| titletext = This doesn't take into account the energy imparted by orbital motion (or gravity assists or the Oberth effect), all of which can make it easier to reach outer planets.&lt;br /&gt;
}}&lt;br /&gt;
{{TOC}}&lt;br /&gt;
&lt;br /&gt;
The xkcd page links to [http://xkcd.com/681_large/ a much larger version].&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
&lt;br /&gt;
The comic shows the gravitational potential (energy transferred per unit mass due to gravity) for the positions of each planet in the solar system — including some moons and Saturn's rings. An object traveling along an upward slope loses energy, while an object traveling along a downward slope gains energy. &lt;br /&gt;
&lt;br /&gt;
Escaping a planet or moon's orbit requires enough energy (e.g. by walking, jumping, or rocket) to reach the top of either peak that defines the edge of the well. The peak to the left indicates the minimum energy required to exit orbit. The peak to the right indicates the maximum energy required to exit orbit. In order to exit orbit with the minimum amount of energy, you would have to travel towards the center of the solar system; to exit orbit with the maximum amount of energy, you would have to travel away from the center of the solar system (the Sun). In reality, the strength of gravity decreases with distance from the planet. However, a comparison of energy expended to escape the gravitational pull allows for a simpler comparison between the objects.&lt;br /&gt;
&lt;br /&gt;
The height of the graph is scaled to kilometers via the gravitational potential an object has at the given height assuming at a constant acceleration due to Earth's surface gravity. The {{w|Sun|Sun's}} gravity well is not shown in its entirety, but is just indicated on the far left as ''&amp;quot;Very very far down&amp;quot;''. Had it been shown in its full extent it would have made the rest of the drawing so small in comparison that it would have been unreadable. As the gravitational potential increases with distance from the sun, the graph has a general upward slope. To rise out of each well on the diagram, and therefore escape the planet's gravity, it would require the same energy required to rise out of a physical well of that depth at Earth's surface gravity. &lt;br /&gt;
&lt;br /&gt;
The length of each gravity well is scaled to the diameter of the planet and the spacing between the planets is not to scale with distance from the sun. This is necessary to make the graph readable. Because the distances between the planets are condensed, the gravitational potential - from the gravity pulling toward the sun - accumulates quicker. This is the reason for the large peaks between the planets. The moons shown in the chart are at the appropriate distance from their respective planets' gravity wells for their orbits. &lt;br /&gt;
&lt;br /&gt;
Each planet is shown cut in half at the bottom of its well, with the depth of the well measured down to the planet's flat surface.&lt;br /&gt;
&lt;br /&gt;
==== Inner Planets ====&lt;br /&gt;
* {{w|Mercury (planet)|Mercury}} — no facts listed&lt;br /&gt;
* {{w|Venus (planet)|Venus}} — no facts listed&lt;br /&gt;
* {{w|Earth}} and {{w|Moon}}: The listed depth of the gravity well at Earth was originally listed at 5478&amp;amp;nbsp;km rather than the correct value of 6379&amp;amp;nbsp;km seen in the cutout.  Randall has since corrected it.  The Moon's is 288&amp;amp;nbsp;km.&lt;br /&gt;
* {{w|Mars}}: The listed depth of the gravity well of Mars is 1286&amp;amp;nbsp;km.&lt;br /&gt;
&lt;br /&gt;
==== Outer Planets ====&lt;br /&gt;
* {{w|Jupiter}}: Jupiter is so massive and dense that it is one thirteenth the mass of a small {{w|Brown dwarf}} which is the smallest kind of star. Saturn, while similar in size, is composed of much lighter gas material. Hence Saturn's mass and therefore its gravitational pull are much smaller. If a few dozen times the mass of gasses contained in Jupiter had condensed in that location, the gravitational pull would cause the pressure and temperature to increase to a level that is sufficient to ignite {{w|Nuclear fusion|nuclear fusion}}. Had that happened during the creation of our solar system, we would have two {{w|Sun|Suns}} and our solar system would be a {{w|Binary system (astronomy)|Binary system}}.  Jupiter has {{w|Moons of Jupiter|67 moons}} of which 3 are shown;&lt;br /&gt;
** {{w|Ganymede (moon)|Ganymede}} — moon of Jupiter, no facts given&lt;br /&gt;
** {{w|Io (moon)|Io}} — moon of Jupiter, no facts given&lt;br /&gt;
** {{w|Europa (moon)|Europa}} — moon of Jupiter, no facts given&lt;br /&gt;
&lt;br /&gt;
* {{w|Saturn}}: The diagram shows the position of the {{w|rings of Saturn}} in Saturn's gravity well. Saturn's rings start fairly near the planet and extend out quite far, therefore multiple stripes are shown in the figure. The rings are also shown in multiple colors and roughly match the observed colors from photos take by the {{w|Cassini–Huygens|Cassini spacecraft}} expedition as it passed Saturn. All of the colors of the planets and moons represent the predominant color of that object as observed from earth. Saturn has {{w|Moons of Saturn|62 moons}} of which one is shown;&lt;br /&gt;
** {{w|Titan (moon)|Titan}}, a moon of Saturn. The figures on Titan are sirens, a reference to Kurt Vonnegut's ''{{w|The Sirens of Titan}}''.&lt;br /&gt;
&lt;br /&gt;
* {{w|Uranus}}: Notably absent is any &amp;quot;your-anus&amp;quot; jokes.&lt;br /&gt;
* {{w|Neptune}}: Megan's quote is a paraphrase of {{w|Carl Sagan|Carl Sagan's}} quote, &amp;quot;...but from a planet orbiting a star in a distant globular cluster, a still more glorious dawn awaits, not a sun-rise, but a galaxy rise.&amp;quot; [http://www.youtube.com/watch?v=zSgiXGELjbc Video here]&lt;br /&gt;
&lt;br /&gt;
==== Cut outs and sketches====&lt;br /&gt;
The following items are listed from top to bottom and left to right.&lt;br /&gt;
&lt;br /&gt;
* Mars moons: The Mars cutout shows the Mars moon system, including the moons Deimos and Phobos. The depth of the Mars gravity well is listed at 1286&amp;amp;nbsp;km.&lt;br /&gt;
** {{w|Deimos (moon)|Deimos}}: The gravity on Deimos, a moon of Mars, is so weak that a bike jump would be sufficient to escape its gravity.&lt;br /&gt;
** {{w|Phobos (moon)|Phobos}}: The gravity on Phobos, a moon of Mars, is so weak that you could launch a baseball into space simply by throwing it.&lt;br /&gt;
&lt;br /&gt;
* Your mom and a local football team: The sketch next to Jupiter is playing on the classic &amp;quot;Yo Mama&amp;quot; joke. It combines &amp;quot;Yo Mama is so fat&amp;quot; and &amp;quot;Yo Mama is so horny&amp;quot;. The sketch implies that she has a huge gravitational pull because she is very fat, and has sex with an entire football team by demonstrating a football team falling into her very deep gravity well. A &amp;quot;Yo Mama&amp;quot; joke also appears in comic [[89: Gravitational Mass]].&lt;br /&gt;
&lt;br /&gt;
* Earth's Moon: The cut out shows the significant difference in strength between the {{w|gravity well}} of the Earth and the Moon. Cueball comments that the {{w|Apollo Lunar Module|Apollo Lunar Module}} was very small and the {{w|Saturn V}} rocket was very large because escaping the Earth's gravity well takes much more energy than escaping the Moon's. The cut out also shows objects like the {{w|International_Space_Station|International Space Station}}, the {{w|Space shuttle|space shuttle}}, {{w|GPS satellite|GPS satellites}} and {{w|Geostationary orbit|geo-stationary satellites}} at their respective positions within Earth's gravity well. The depth of Earth's gravity well is listed correctly at 6 379&amp;amp;nbsp;km (note the difference from the non-cutout number). The depth of the Moon's gravity well is listed at 288&amp;amp;nbsp;km.&lt;br /&gt;
&lt;br /&gt;
=== How to calculate gravity wells ===&lt;br /&gt;
The text near the bottom of Jupiter's gravity well explains that the depth of the well is mass-of-planet over radius-of-planet with Newton's constant and 9.81&amp;amp;nbsp;m/s² as constants, where 9.81&amp;amp;nbsp;m/s² is the acceleration of a free falling body at Earth's gravity.&lt;br /&gt;
&lt;br /&gt;
The calculation for a gravity well is:&lt;br /&gt;
:depth = (G * Planet-mass ) / (9.81 m/s&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; * Planet-radius)&lt;br /&gt;
::where G is {{w|Isaac Newton|Newton}}'s {{w|gravitational constant}}, and&lt;br /&gt;
::9.81 m/s&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; is the {{w|acceleration}} rate of a {{w|Gravity of Earth|free falling body on earth}} at sea level (g).&lt;br /&gt;
&lt;br /&gt;
====Title text====&lt;br /&gt;
The title text indicates that the planets motion can affect the amount of energy for escape velocity. It is possible to change speed by using the planets orbital speed and gravity. This is known as a performing a slingshot or a {{w|gravity assist}}, and is done to gain speed or to brake when needed. The use of rocket engines are more effective when used at a high speed slingshot maneuver, which is known as the {{w|Oberth effect}}, where most energy is going into moving the rocket as opposed to moving the exhaust — conserving the maximum useful energy.   On earth the same principle is used when launching rockets. Rockets are always launched in an eastward direction to make maximum use of the rotational energy of the earth. Launching rockets in a westward direction would require significant additional energy. Because of this most artificial satellites are flying east around the globe.&lt;br /&gt;
&lt;br /&gt;
The size of the gravity-well as described in this comic is not accounting for these factors. Therefore, leaving the solar system (or any of the gravity wells of the planets) could require less energy than described by the graph, assuming that the launch and slingshots are properly designed and executed.&lt;br /&gt;
&lt;br /&gt;
==== Escape Velocities ====&lt;br /&gt;
The following table was adapted from the table in {{w|Escape velocity#List of escape velocities|Escape velocity}}, using ''h'' = ''V_e''^2 / 2''g'':&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot; border=&amp;quot;1&amp;quot;&lt;br /&gt;
| Location || with respect to || Ve (km/s) || Well depth (km) ||&lt;br /&gt;
| Location || with respect to || Ve (km/s) || Solar well (Mm) || Total depth (Mm)  &lt;br /&gt;
|-&lt;br /&gt;
| on the Sun, || the Sun's gravity: || 617.5 || 19,435,000 || || || || || || 19,435 &lt;br /&gt;
|-&lt;br /&gt;
| on Mercury, || Mercury's gravity: ||  4.3 || 942 ||&lt;br /&gt;
| at Mercury, || the Sun's gravity: || 67.7 || 233.6 || 235 &lt;br /&gt;
|-&lt;br /&gt;
| on Venus,  || Venus' gravity:     || 10.3 || 5,407 ||&lt;br /&gt;
| at Venus,  || the Sun's gravity:  || 49.5 || 124.9 || 130 &lt;br /&gt;
|-&lt;br /&gt;
| on Earth, || the Earth's gravity: || 11.2 || 6,393 ||&lt;br /&gt;
| at the Earth/Moon, || the Sun's gravity: || 42.1 || 90.3 || 97 &lt;br /&gt;
|-&lt;br /&gt;
| on the Moon, || the Moon's gravity: || 2.4 || 294 || &lt;br /&gt;
| at the Moon, || the Earth's gravity: || 1.4 ||  || 91 &lt;br /&gt;
|-&lt;br /&gt;
| on Mars, || Mars' gravity: || 5 || 1,274 ||&lt;br /&gt;
| at Mars, || the Sun's gravity: || 34.1 || 59.3 || 61 &lt;br /&gt;
|-&lt;br /&gt;
| on Jupiter, || Jupiter's gravity: || 59.5 || 180,400 ||&lt;br /&gt;
| at Jupiter, || the Sun's gravity: || 18.5 || 17.4 || 198 &lt;br /&gt;
|-&lt;br /&gt;
| on Ganymede, || Ganymede's gravity: || 2.7 || 372 || || || || ||  &lt;br /&gt;
|-&lt;br /&gt;
| on Saturn, || Saturn's gravity: || 35.6 || 64,600 ||&lt;br /&gt;
| at Saturn, || the Sun's gravity: || 13.6 || 9.43 || 74 &lt;br /&gt;
|-&lt;br /&gt;
| on Uranus, || Uranus' gravity: || 21.2 || 22,907 ||&lt;br /&gt;
| at Uranus, || the Sun's gravity: || 9.6 || 4.7 || 28 &lt;br /&gt;
|-&lt;br /&gt;
| on Neptune, || Neptune's gravity: || 23.6 || 28,400 || &lt;br /&gt;
| at Neptune, || the Sun's gravity: || 7.7 || 3.02 || 31 &lt;br /&gt;
|-&lt;br /&gt;
| on Pluto, || Pluto's gravity: || 1.2 || 73 || || || || || &lt;br /&gt;
|-&lt;br /&gt;
|at Solar System &amp;lt;br/&amp;gt;galactic radius, || the Milky Way's gravity: || 525 || 14,000 &lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:'''Main Text'''&lt;br /&gt;
:Gravity Wells scaled to Earth surface gravity&lt;br /&gt;
:This chart shows the &amp;quot;depth&amp;quot; of various solar system gravity wells.&lt;br /&gt;
:Each well is scaled such that rising out of a physical well of that depth — in constant Earth &amp;lt;u&amp;gt;surface&amp;lt;/u&amp;gt; gravity — would take the same energy as escaping from that planet's gravity in reality.&lt;br /&gt;
:Each planet is shown cut in half at the bottom of its well, with the depth of the well measured down to the planet's ''flat'' surface.&lt;br /&gt;
:The planet sizes are to the same scale as the wells. Interplanetary distances are not to scale.&lt;br /&gt;
:Depth = (G × PlanetMass) / (g × PlanetRadius)&lt;br /&gt;
:G = Newton's constant&lt;br /&gt;
:g = 9.81 m/s&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:'''Planetary Descriptions'''&lt;br /&gt;
:To Sun, very very far down&lt;br /&gt;
:Mercury&lt;br /&gt;
:Venus&lt;br /&gt;
:Earth - 6379 km [originally 5,478 km]&lt;br /&gt;
:Moon - 288 km&lt;br /&gt;
:Mars - 1,286 km&lt;br /&gt;
:Ganymede&lt;br /&gt;
:Io&lt;br /&gt;
:Jupiter&lt;br /&gt;
::[A drawing of a &amp;quot;very deep&amp;quot; gravity well, &amp;quot;Your mom&amp;quot; at the bottom, several member of &amp;quot;local football team&amp;quot; falling down towards her.]&lt;br /&gt;
::Jupiter is not much larger than Saturn, but much more massive. At its size, adding more mass just makes it denser due to the extra squeezing of gravity.&lt;br /&gt;
::If you dropped a few dozen more Jupiters into it, the pressure would ignite fusion and make it a star.&lt;br /&gt;
:Europa&lt;br /&gt;
:Titan&lt;br /&gt;
::Two alarms: Weeoooeeoooeeooo&lt;br /&gt;
:Saturn&lt;br /&gt;
::Rings&lt;br /&gt;
:Uranus&lt;br /&gt;
:Neptune&lt;br /&gt;
::Megan: An even more glorious dawn awaits!&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:'''Mars Inset'''&lt;br /&gt;
:[Mars gravity well, with one of the Mars rovers on its surface, with its moons Deimos and Phobos as smaller gravity wells.]&lt;br /&gt;
&lt;br /&gt;
:[Figure of a man (to scale) in Deimos's gravity well.]&lt;br /&gt;
:You could escape Deimos with a bike and a ramp.&lt;br /&gt;
&lt;br /&gt;
:[Figure of a man (to scale) in Phobos's gravity well.]&lt;br /&gt;
:A thrown baseball could escape Phobos.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:'''Earth Inset'''&lt;br /&gt;
:[Zoomed-in view of Earth/moon gravity well, featuring the relative locations of the atmosphere, Low Earth Orbit, the International Space Station, the Space Shuttle, GPS satellites, and satellites in geosynchronous orbit.]&lt;br /&gt;
:Cueball: This is why it took a huge rocket to get to the moon but only a small one to get back.&lt;br /&gt;
&lt;br /&gt;
:It takes the same amount of energy to launch something on an escape trajectory away from Earth as it would to launch it 6,000 km upward under constant 9.81 m/s&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; Earth gravity.&lt;br /&gt;
&lt;br /&gt;
:Hence, Earth's well is 6,000 km deep.&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
*A print version of this comic is available in the [https://store.xkcd.com/products/gravity-wells-poster xkcd store].&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Comics with color]]&lt;br /&gt;
[[Category:Large drawings]]&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:American football]]&lt;br /&gt;
[[Category:Baseball]]&lt;br /&gt;
[[Category:Your Mom]]&lt;br /&gt;
[[Category:Space]]&lt;br /&gt;
[[Category:Mars rovers]]&lt;br /&gt;
[[Category:Comics with xkcd store products]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=482:_Height&amp;diff=204726</id>
		<title>482: Height</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=482:_Height&amp;diff=204726"/>
				<updated>2021-01-15T18:29:29Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: +cat&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 482&lt;br /&gt;
| date      = September 29, 2008&lt;br /&gt;
| title     = Height&lt;br /&gt;
| before    = [[#Explanation|↓ Skip to explanation ↓]]&lt;br /&gt;
| image     = height.png&lt;br /&gt;
| titletext = Interestingly, on a true vertical log plot, I think the Eiffel Tower's sides would really be straight lines.&lt;br /&gt;
}}&lt;br /&gt;
{{TOC}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
''Height'' uses a {{w|logarithmic scale}} to depict the contents of the {{w|universe}} at progressively smaller distances from Earth (less high above the Earth), starting at the highest possible &amp;quot;point&amp;quot;, the edge of the {{w|observable universe}}, going all the way down to the grass beneath our feet. The comic is a direct companion piece to [[485: Depth]], also released on a Monday the week after this one. ''Depth'' similarly uses the logarithmic scale to depict the Earth at progressively greater magnification (going &amp;quot;deeper&amp;quot; down), from Earth's surface (the grass) to the interior of a single proton.&lt;br /&gt;
&lt;br /&gt;
At the very top the top (edge) of the observable universe is described as being 46 billion {{w|light years}} above the Earth. The universe is &amp;quot;only&amp;quot; about {{w|Age of the universe|13.8 billion years old}}, so the {{w|cosmic background radiation}} that reaches the Earth today, has also only traveled 13.8 billion light years. However, during that time {{w|Metric expansion of space|the universe has expanded}}, so the galaxies that formed from that spot where this background radiation was emitted 13.8 billion years ago, would now be 46 billion light years away. This has lead to many {{w|Observable_universe#Misconceptions_on_its_size|misconceptions regarding the size}} the most typical being that the radius of the observable universe is &amp;quot;only&amp;quot; 13.8 billion light years. See this video, ''[https://www.youtube.com/watch?v=QXfhGxZFcVE How Do You Measure the Size of the Universe?]'' for a great explanation of the 46 billion light years.&lt;br /&gt;
&lt;br /&gt;
To the right of the text, [[Black Hat]] stands atop the comic, having just dropped a cat off the edge head first; he is clearly going to test if the cat will land on its feet, being a jerk per his usual character. It will take some time though, before the cat reaches Earth... &lt;br /&gt;
&lt;br /&gt;
As one scrolls down, the depicted distances become less compressed, until arriving at the surface of Earth, all the while approaching a 1:1 scale with real-life distances. As shown in [[1162: Log Scale]], if [[Randall]] didn't do this, the comic would be much, MUCH longer.&lt;br /&gt;
&lt;br /&gt;
In this comic, most objects that are grounded on Earth are scaled logarithmically on the vertical axes and linearly on the horizontal axes (some are scaled linearly on both axes). Displaying objects in this manner noticeably distorts their shape; the Great Pyramid, for instance, looks not like a pyramid but like a bullet. &lt;br /&gt;
&lt;br /&gt;
Outside of the Earth's atmosphere, the objects are placed at their actual distances from Earth on the log scale, but their shapes are not subjected to the logarithmic scaling of Earth objects, instead appearing as they would be seen (otherwise, round objects like the sun would appear more egg shaped, with the flatter side facing upward). However, objects are still much larger or much smaller than they would be in real life, in order to allow them to be properly seen.&lt;br /&gt;
&lt;br /&gt;
In the title text, Randall muses on how the inwardly-curved sides of the {{w|Eiffel Tower}} might actually become perfectly straightened when subjected to this logarithmic distortion, although it is shown to bulge in the comic proper, meaning Randall probably doesn't fully believe his own musings. The actual shape of the Tower approximates an {{w|Exponential function|exponential curve}}, which would indeed give a straight line on a log scale, although it was actually designed by {{w|Gustave Eiffel}} to minimize wind resistance rather than to be mathematically exact (the design is so perfect that the amount the Tower sways in the wind is less than the amount it is distorted due to thermal expansion of the sunlit side).&lt;br /&gt;
&lt;br /&gt;
===Objects===&lt;br /&gt;
All objects are sorted from bottom to top by their maximum distance from earth for objects in a solar orbit, and their current distance for others.&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Distance&lt;br /&gt;
! Object&lt;br /&gt;
! Description&lt;br /&gt;
|-&lt;br /&gt;
| 435&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;24&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| Black Hat and cat&lt;br /&gt;
| Black Hat dropping a cat off the top of the comic, presumably to determine whether it will land on its feet.&lt;br /&gt;
|-&lt;br /&gt;
| 435&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;24&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | Top of {{w|observable universe}}&lt;br /&gt;
|-&lt;br /&gt;
| 11.3&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;24&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Hubble Deep Field}} objects&lt;br /&gt;
| Objects of extremely distant galaxies found in a long-exposure photograph by of the Hubble telescope, 12 billion light-years away. The right most object is probably intended to be a pulsar, schematically shown from the side.&lt;br /&gt;
|-&lt;br /&gt;
| 9.46&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;24&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | One billion light years&lt;br /&gt;
|-&lt;br /&gt;
| 3.1&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;24&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Quasar}}&lt;br /&gt;
| A supermassive black hole at the center of some young, distant galaxies, the energy released by stuff as it falls into them makes them the brightest known objects, the black hole eventually gets too big so the huge amounts of energy can't escape, but while they're active, they outshine entire clusters of galaxies.&lt;br /&gt;
|-&lt;br /&gt;
| 2.36&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;24&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Great Attractor}}&lt;br /&gt;
| An unusual concentration of intergalactic mass. (It could also just be [[502: Dark Flow|Your Mom]]).&lt;br /&gt;
|-&lt;br /&gt;
| 425&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;21&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Antennae Galaxies}} (colliding)&lt;br /&gt;
| A pair of colliding galaxies.&lt;br /&gt;
|-&lt;br /&gt;
| 23.6&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;21&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Andromeda Galaxy}}&lt;br /&gt;
| A sibling to our Milky Way. It is the nearest spiral galaxy to ours.&lt;br /&gt;
|-&lt;br /&gt;
| 23.6&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;21&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| Holy crap lots of space&lt;br /&gt;
| There is a lot of {{w|Void (astronomy)|nearly empty space between galaxies}}.&lt;br /&gt;
|-&lt;br /&gt;
| 9.46&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;21&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | One million light years&lt;br /&gt;
|-&lt;br /&gt;
| 2.38&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;21&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| [http://knowyourmeme.com/memes/cat-on-a-keyboard-in-space Cat on a keyboard in space]&lt;br /&gt;
| An internet meme featuring a picture of a cat sitting on a musical keyboard, superimposed on an image of space.&lt;br /&gt;
|-&lt;br /&gt;
| 1.56&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;21&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Magellanic Clouds}}&lt;br /&gt;
| These clouds are a pair of nearby dwarf galaxies.&lt;br /&gt;
|-&lt;br /&gt;
| 263&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| Edge of Galaxy&lt;br /&gt;
| The edge of the {{w|Milky Way}} galaxy, the galaxy in which we reside.&lt;br /&gt;
|-&lt;br /&gt;
| 245&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Galactic Center}}&lt;br /&gt;
| The center of the Milky Way galaxy.&lt;br /&gt;
|-&lt;br /&gt;
| 61.5&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Crab Nebula}}&lt;br /&gt;
| Nebula are supernova remnants.&lt;br /&gt;
|-&lt;br /&gt;
| 14.2&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Horsehead Nebula}}&lt;br /&gt;
| A dark nebula that is part of the Orion Constellation.&lt;br /&gt;
|-&lt;br /&gt;
| 12.7&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Orion Nebula}}&lt;br /&gt;
| A nebula that is part of the Orion Constellation, just south of Orion's Belt.&lt;br /&gt;
|-&lt;br /&gt;
| 8.14&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Rigel}}&lt;br /&gt;
| The brightest star in the Orion Constellation it is actually a triple star system known alternatively as Beta Orionis.&lt;br /&gt;
|-&lt;br /&gt;
| 6.08&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Betelgeuse}}&lt;br /&gt;
| The star Betelgeuse is displayed along with the location of {{w|Ford_Prefect (character)|Ford Prefect}} on his home planet which orbits Betelgeuse. Ford Prefect is a fictional character from the science fiction parody {{w|The Hitchhiker's Guide to the Galaxy}}.&lt;br /&gt;
|-&lt;br /&gt;
| 4.20&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Pleiades}}&lt;br /&gt;
| The Pleiades also have a derogatory remark (for those who do not know how to recognize them), as per [[66: Abusive Astronomy]]. This is probably because they are Randall's favorite astronomical entity as is stated at the very bottom of the [http://www.xkcd.com/about/ about] page on xkcd.&lt;br /&gt;
|-&lt;br /&gt;
| 2.90&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;18&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| The [http://en.memory-alpha.org/wiki/Romulan_Neutral_Zone Romulan Neutral Zone]&lt;br /&gt;
| This marks the edge of the {{w|Star Trek}} Federation.&lt;br /&gt;
|-&lt;br /&gt;
| 931&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; |  The first radio broadcast was in January 1910. Since radio waves travel at the speed of light, and this was published in September 2008 this the radio waves traveled about 98.5 light years. See {{w|Contact (1997 film)}} for a depiction of this. This is also referenced in [[1212: Interstellar Memes]].&lt;br /&gt;
|-&lt;br /&gt;
| 350&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Arcturus}}&lt;br /&gt;
| An orange giant star that is part of the Boötes constellation.&lt;br /&gt;
|-&lt;br /&gt;
| 320&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Pollux}}&lt;br /&gt;
| One of the most distinct stars in the Gemini Constellation it is large Orange Giant with an apparent visual magnitude of 1.1&lt;br /&gt;
|-&lt;br /&gt;
| 242&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| The edge of {{w|Federation Sector 0-0-1}}&lt;br /&gt;
| The sector of space assigned to Earth in {{w|Star Trek}}.&lt;br /&gt;
|-&lt;br /&gt;
| 224&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Iraq and weapons of mass destruction|&amp;quot;missing WMDs&amp;quot;}}&lt;br /&gt;
| A reference to the alleged weapons of mass destruction that were used as a pretense to mobilize the world population against Iraq, and start the Iraq war.&lt;br /&gt;
|-&lt;br /&gt;
| 81.3&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Sirius}}&lt;br /&gt;
|Also known as Alpha Canis Majoris or the Dog Star, it is actually a binary system of Stars consisting of a main sequence white star and a small white dwarf.&lt;br /&gt;
|-&lt;br /&gt;
| 56.6&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Barnard's Star}}&lt;br /&gt;
| Barnard's star is a very small red dwarf that is of great interest to astronomers as an achievement in the SIM ({{w|Space Interferometry Mission}}) to find a celestial object out of solar system that is as small as 3 earth masses&lt;br /&gt;
|-&lt;br /&gt;
| 41.3&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Alpha Centauri}}&lt;br /&gt;
| Alpha Centauri is the closest star system to our planet.&lt;br /&gt;
|-&lt;br /&gt;
| 30.9&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | One {{w|parsec}} (= 3.26 light-years).&lt;br /&gt;
|-&lt;br /&gt;
| 9.46&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | One {{w|light-year}}.&lt;br /&gt;
|-&lt;br /&gt;
| 15.0&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;15&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Oort cloud}}&lt;br /&gt;
| A halo of ice balls surrounding our solar system, but missing the {{w|Kuiper belt}} between Neptune and the Oort cloud. The Oort cloud is only theorized to exist, with no confirmed direct observations, so Randall has written a question mark (?) next to this region of the graph.&lt;br /&gt;
|-&lt;br /&gt;
| 350&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Bupkis}}&lt;br /&gt;
| Yiddish for &amp;quot;nothing&amp;quot;. Only a handful of objects are known to orbit between the Kuiper Belt and the Oort Cloud.&lt;br /&gt;
|-&lt;br /&gt;
| 55.0&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| A comet which will destroy earth in late 2063 &lt;br /&gt;
| To coincide with the latest biblically based prophesy for the [http://www.askelm.com/prophecy/p971105.htm end of the world].&lt;br /&gt;
|-&lt;br /&gt;
| 19.5&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Voyager 1}}&lt;br /&gt;
| An early space probe. Distance correct as of 20th Nov 2014, click [http://voyager.jpl.nasa.gov/where/ here] to see NASA's live distance counter.&lt;br /&gt;
|-&lt;br /&gt;
| 16.7&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Pioneer 10}}&lt;br /&gt;
| Listed distance is an estimate based on {{w|Pioneer_10#Current_status|this information}}.&lt;br /&gt;
|-&lt;br /&gt;
| 17.7&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Pioneer 11}}&lt;br /&gt;
| By the similarity in appearance to Pioneer 10 this unlabeled probe must be Pioneer 11. Listed distance is an estimate based on {{w|Pioneer_11#Current_status|this information}}.&lt;br /&gt;
|-&lt;br /&gt;
| 14.5&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Eris (dwarf planet)|Eris}}&lt;br /&gt;
| One of a pair of {{w|Trans-Neptunian object}}s now classified as {{w|dwarf planet}}s. The &amp;quot;All hail Discordia!&amp;quot; after Eris is a reference to {{w|Discordianism}}, a somewhat tongue-in-cheek religion based around the goddess Eris. The distance is the maximum distance from earth.&lt;br /&gt;
|-&lt;br /&gt;
| 7.50&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Pluto}}&lt;br /&gt;
| One of a pair of {{w|Trans-Neptunian object}}s now classified as {{w|dwarf planet}}s. Pluto was originally classified as the 9th planet of the Solar system. Many people were appalled when it was suddenly degraded to dwarf planet. Obviously Randall does not think much of these people thus the comment: ''Not a planet. Neener neener''. The distance is the maximum distance of Pluto from Earth.&lt;br /&gt;
|-&lt;br /&gt;
| 4.70&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Neptune}} &lt;br /&gt;
| Neptune is displayed here with its moons. Neptune is the eighth and final planet in our solar system.&lt;br /&gt;
|-&lt;br /&gt;
| 3.20&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Uranus}} &lt;br /&gt;
| Uranus is dispayed here with its moons. Uranus is the seventh planet in our solar system.&lt;br /&gt;
|-&lt;br /&gt;
| 1.67&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Saturn}} &lt;br /&gt;
| Saturn is displayed along with its moons. One of Saturn's moons, most likely {{w|Enceladus}}, is labeled as a potential location to find life. Enceladus was known in 2008 to have a possible subsurface ocean and active geysers, and a paper co-authored by well-known planetary scientist Caroline Porco in Astrobiology during that year (when the comic was published) spelt out the case for searching for life there (McKay et al. 2008 &amp;quot;The Possible Origin and Persistence of Life on Enceladus and Detection of Biomarkers in the Plume&amp;quot;, Astrobiology 8(5):909-919). In 2015, the {{w|Cassini probe}} sampled material thought to be from Enceladus' geysers, and scientists have found evidence that it's subsurface ocean closely resembles a particular kind of deep sea hydrothermal environment on Earth known to harbor life.&lt;br /&gt;
&lt;br /&gt;
A more distant possibility is that Randall is referencing Saturn's largest (and much more well known moons) {{w|Titan (moon)|Titan}}, the only known moon to have an atmosphere and lakes. It was long predicted that there may be bodies of liquid on the surface filled with liquid methane and ethane (Titan is too cold for liquid water and life as we know it, but ethane and methane remain a liquid at those temperatures). There is some speculation that exotic forms of life based on extremely cold exotic chemistries may form in such conditions, with liquid hydrocarbons playing the role of the solvent (the role water plays in terrestrial life).&lt;br /&gt;
|-&lt;br /&gt;
| 928&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;m&lt;br /&gt;
 | {{w|Jupiter}} &lt;br /&gt;
| Jupiter is displayed along with its moons. One of Jupiter's moons, {{w|Europa (moon)|Europa}}, is labeled as a potential location to find life.  Europa may be covered by a deep ocean of water found under a layer of ice many kilometers thick. Some hypothesize that life could have formed in such oceans.&lt;br /&gt;
|-&lt;br /&gt;
| 222&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| Asteroids&lt;br /&gt;
| The {{w|Asteroid|Asteroid belt}} contains a spaceship from {{w|Asteroids (video game)}}&lt;br /&gt;
|-&lt;br /&gt;
| 133&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Mars}}&lt;br /&gt;
| Note the path, reflecting the fact that their distances from Earth vary as the planets move in their orbits with a maximum distance of 401 million km and a minimum of 54.6 million km.&lt;br /&gt;
|-&lt;br /&gt;
| 114&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Venus}}&lt;br /&gt;
| Note the path, reflecting the fact that their distances from Earth vary as the planets move in their orbits with a maximum distance of 261 million km and a minimum of 37.7 million km.&lt;br /&gt;
|-&lt;br /&gt;
| 138&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Mercury}}&lt;br /&gt;
| Mercury is the innermost planet in our solar system. The distance shown is the maximum distance from Earth.&lt;br /&gt;
|-&lt;br /&gt;
| 149&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Sun}}&lt;br /&gt;
| The Sun is the star at the center of our solar system, around which the Earth and the other planets orbits.{{Citation needed}}&lt;br /&gt;
|-&lt;br /&gt;
| 16.3&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Discovery One}}&lt;br /&gt;
| The Discovery One from {{w|2001: A Space Odyssey}}, referring to the quote &amp;quot;open the pod bay door, HAL.&amp;quot; Also may be a reference to [[375: Pod Bay Doors]].&lt;br /&gt;
|-&lt;br /&gt;
| 9.43&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| Planet Express&lt;br /&gt;
| The spaceplane is most likely the Planet Express from {{w|Futurama}}, where Fry once discussed &amp;quot;a big heaping bowl of salt.&amp;quot; &lt;br /&gt;
|-&lt;br /&gt;
| 400&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| Human Altitude Record &lt;br /&gt;
| Achieved by the team of {{w|Apollo 13}} approximately 100&amp;amp;nbsp;km higher than the remaining Apollo missions.&lt;br /&gt;
|-&lt;br /&gt;
| 384&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Moon}} &lt;br /&gt;
| The Moon is the Earth's only natural satellite.&lt;br /&gt;
|-&lt;br /&gt;
| 90.4&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Snoop Dogg}}&lt;br /&gt;
| A tongue-in-cheek reference to a rapper notorious for smoking marijuana, shown as having the second-highest altitude record. Someone who is taking drugs is said to be getting high.&lt;br /&gt;
|-&lt;br /&gt;
| 60.5&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Space elevator}}&lt;br /&gt;
| A proposed method of transporting cargo or people into orbit, consisting of a large mass beyond geosynchronous orbit, a station at the geosynchronous point, a cable connecting it to the Earth, and a climber that can scale the cable. Space elevators are also seen in [[697: Tensile vs. Shear Strength]] and [[536: Space Elevators]].&lt;br /&gt;
|-&lt;br /&gt;
| 42.1&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | {{w|Geosynchronous orbit|Geosynchronous Orbit}}&lt;br /&gt;
|-&lt;br /&gt;
| 20.2&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|GPS (satellite)|GPS Satellites}}&lt;br /&gt;
| GPS satellites are used for global positioning.&lt;br /&gt;
|-&lt;br /&gt;
| 3.94&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Lunar Lander}} &lt;br /&gt;
| The quote is a reference to {{w|Contact (1997 film)}} where the main character Ellie Arroway after witnessing a celestial light show up close says &amp;quot;Poetry! They should've sent a poet.&amp;quot;.&lt;br /&gt;
|-&lt;br /&gt;
| 800&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Space debris|Space Junk}}&lt;br /&gt;
| There is a large quantity of defunct objects in orbit around the earth. Amongst other things, this includes old satellites, rocket stages and fragments from collisions or disintegration. Space junk is also referenced in [[1242: Scary Names]] under the title {{w|Kessler syndrome}}&lt;br /&gt;
|-&lt;br /&gt;
| 422.5&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|International Space Station}}&lt;br /&gt;
| The ISS (International Space Station) is a multinational effort to put a research vessel in space. It is currently the largest artificial object in Earth's orbit, as well as the location of the longest continuous human presence in space.&lt;br /&gt;
|-&lt;br /&gt;
| 100&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | The {{w|Edge of space|official edge of space}} as defined by the {{w|Kármán line}}&lt;br /&gt;
|-&lt;br /&gt;
| 76.0&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Meteors}}&lt;br /&gt;
| Meteors are chunks of rock (usually asteroids) that burn up in the atmosphere, producing the bright light associated with them. If they are large enough to hit the ground, they become meteorites, which is why Munroe labeled them only in the upper atmosphere.&lt;br /&gt;
|-&lt;br /&gt;
| 25.0&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|High-altitude balloon|High-altitude balloons}}&lt;br /&gt;
|  Unmanned balloons, typically filled with helium or hydrogen. The current altitude record was set in 2002 by a balloon named BU60-1 which reached 53,000m.&lt;br /&gt;
|-&lt;br /&gt;
| 16.1&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | 1/10 ATM = 0.1 {{w|Atmospheric pressure|atmosphere of pressure}}&lt;br /&gt;
|-&lt;br /&gt;
| 12.0&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Airliner|Airliners}}&lt;br /&gt;
| This is a typical cruising altitude of jet aircraft, equating to roughly 40,000 feet. (Aircraft altitude tends to be specified in feet rather than metres (yay!?)) &lt;br /&gt;
|-&lt;br /&gt;
| 8.84&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Mount Everest}} &lt;br /&gt;
| The Earths highest mountain, located in the {{w|Himalayas|Himalayan mountain range}} in South Asia.&lt;br /&gt;
|-&lt;br /&gt;
| 8.00&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Cory Doctorow}} &lt;br /&gt;
| Cory Doctorow is a [[:Category:Comics featuring Cory Doctorow|recurring theme]] in xkcd. He was first seen in a balloon in [[239: Blagofaire]].&lt;br /&gt;
|-&lt;br /&gt;
| 6.34&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Space Shuttle Columbia disaster}} &lt;br /&gt;
| The {{w|Space Shuttle Columbia}} and its seven crew were lost when it disintegrated at [http://books.google.co.uk/books?id=6v16AgAAQBAJ&amp;amp;lpg=PA7&amp;amp;ots=LDKQ3nsNHs&amp;amp;dq=shuttle%20columbia%20altitude&amp;amp;pg=PA7#v=onepage&amp;amp;q=shuttle%20columbia%20altitude&amp;amp;f=false approximately 63,400m] in 2003. This number is inconsistent with the height of the graph by a factor of 10 probably a mistype by Randall.&lt;br /&gt;
|-&lt;br /&gt;
| 6.00&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Helicopter}} &lt;br /&gt;
| Though the record for helicopter altitude (without payload) is 12,442m, normal flying is usually performed much lower. In the US, 6000m is into {{w|Class A airspace}}, which is restricted and requires flight under {{w|Instrument Flight Rules}}.&lt;br /&gt;
|-&lt;br /&gt;
| 6.00&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Cloud}} &lt;br /&gt;
| Though not actually labeled there are a couple of clouds shown. While different cloud types vary in height, 6000m is roughly in the middle of the height range for [http://weatherfaqs.org.uk/node/21 clouds in temperate regions].&lt;br /&gt;
|-&lt;br /&gt;
| 5.49&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | 1/2 ATM = 0.5 {{w|Atmospheric pressure|atmosphere of pressure}}&lt;br /&gt;
|-&lt;br /&gt;
| 1.78&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| [[Cueball]] &lt;br /&gt;
| Apparently still using Python as shown in comic [[353: Python]].&lt;br /&gt;
|-&lt;br /&gt;
| 800&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | 800 meters&lt;br /&gt;
|-&lt;br /&gt;
| 800&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Burj Khalifa|Burj Dubai}}  &lt;br /&gt;
| Now known as the Burj Khalifa, is the tallest building in the world. This was also a main feature in [[1110: Click and Drag]].&lt;br /&gt;
|-&lt;br /&gt;
| 500&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | 500 meters&lt;br /&gt;
|-&lt;br /&gt;
| 400&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | 400 meters&lt;br /&gt;
|-&lt;br /&gt;
| 325&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Eiffel Tower}} &lt;br /&gt;
| A famous landmark in Paris, France.&lt;br /&gt;
|-&lt;br /&gt;
| 300&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | 300 meters&lt;br /&gt;
|-&lt;br /&gt;
| 200&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | 200 meters&lt;br /&gt;
|-&lt;br /&gt;
| 150&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| Kite &lt;br /&gt;
| Kite string is commonly sold in large spools; a nice thick spool will probably hold 150 meters. Kites are a [[:Category:Kites|recurring theme]] in xkcd, see for instance [[235: Kite]].&lt;br /&gt;
|-&lt;br /&gt;
| 140&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Great Pyramid of Giza}} &lt;br /&gt;
| One of the Seven Wonders of the Ancient World. It is located in Egypt.&lt;br /&gt;
|-&lt;br /&gt;
| 120&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Pop fly}} &lt;br /&gt;
| In {{w|Baseball}} a 'Pop Fly' is when the batter mis-hits the baseball, which then follows a tall arc deep into the infield where it's easy picking for the other team to catch on its way down. The highest recorded pop fly, not including those that landed in foul territory, was 172 meters.&lt;br /&gt;
|-&lt;br /&gt;
| 115&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Redwood Tree|Redwood trees}} &lt;br /&gt;
| The tallest trees in the world. At 115.61&amp;amp;nbsp;m (379.3&amp;amp;nbsp;ft) {{w|Hyperion (tree)|Hyperion}}, a Coast Redwood, holds the record for the tallest tree in the world.&lt;br /&gt;
|-&lt;br /&gt;
| 100&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; align=&amp;quot;center&amp;quot; style=&amp;quot;background: #ffdead;&amp;quot; | 100 meters&lt;br /&gt;
|-&lt;br /&gt;
| 20.0&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Oak}} &lt;br /&gt;
| While oaks may grow to be in excess of 40m in height, heights of around 20m are more typical. The person in the tree saying, &amp;quot;Hey, squirrels!&amp;quot; is a reference to [[167: Nihilism]].&lt;br /&gt;
|-&lt;br /&gt;
| 16.4&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| Tallest stilts &lt;br /&gt;
| The tallest {{w|stilts}} recorded by the Guinness Book of World Records (as of November 2006) were 16.4 meters, or nearly 54 feet. See also [http://www.explainxkcd.com/wiki/images/8/89/1608_1038x1095y_Hamsterball_and_stilts_room.png these tall stilts] from [[1608: Hoverboard]].&lt;br /&gt;
|-&lt;br /&gt;
| 13.0&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Brachiosaurus|Brachiosaur}}&lt;br /&gt;
| A large genus of dinosaur.&lt;br /&gt;
|-&lt;br /&gt;
| 8.00&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Giraffe}} &lt;br /&gt;
| The tallest living terrestrial animal, with fully grown adults reaching in excess of 5 m. While labeled 8m in the comic, the [http://www.big-animals.com/the-giraffe-the-worlds-tallest-animal/ record] for height is reported at 5.8m. Has been used by Randall for measuring heights, most prominently in the [[what if?]] ''{{what if|44|High Throw}}''.&lt;br /&gt;
|-&lt;br /&gt;
| 1.70&amp;amp;nbsp;×10&amp;lt;sup&amp;gt;0&amp;lt;/sup&amp;gt;m&lt;br /&gt;
| {{w|Human height|Folks}}&lt;br /&gt;
| Determining an average height of the world population is fraught with complications, but as a ballpark figure 1.7m is fairly accurate.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:'''Top of observable universe'''&lt;br /&gt;
:[Black Hat is standing on top, throwing a black kitty down.]&lt;br /&gt;
:Black Cat: Mrowl!&lt;br /&gt;
:[Map of the universe from observable universe to Earth. Each area of item is labeled. Labels left to right, up to down:]&lt;br /&gt;
:(46 billion light years up)&lt;br /&gt;
::Hubble Deep Field Objects&lt;br /&gt;
:-One billion light years-&lt;br /&gt;
::Great Attractor&lt;br /&gt;
::Antennae Galaxies (colliding)&lt;br /&gt;
::Andromeda&lt;br /&gt;
::Holy crap lots of space&lt;br /&gt;
:-One million light years-&lt;br /&gt;
::Magellanic Clouds&lt;br /&gt;
::Edge of galaxy&lt;br /&gt;
::Galactic center&lt;br /&gt;
::Crab Nebula&lt;br /&gt;
::Orion Nebula&lt;br /&gt;
::Horsehead Nebula&lt;br /&gt;
::Romulan neutral zone&lt;br /&gt;
::The Pleiades, duh!&lt;br /&gt;
::Rigel&lt;br /&gt;
::Betelgeuse&lt;br /&gt;
::Ford Prefect&lt;br /&gt;
:[Three arrows are pointing up above three lines with the following label:]&lt;br /&gt;
:-Expanding shell of radio transmissions-&lt;br /&gt;
::[Above a dotted line:]&lt;br /&gt;
::Edge of federation sector 0-0-1&lt;br /&gt;
::Pollux&lt;br /&gt;
::Arcturus&lt;br /&gt;
::Missing WMDs&lt;br /&gt;
::Sirius&lt;br /&gt;
::Barnard's Star&lt;br /&gt;
::Alpha Centauri&lt;br /&gt;
:-One parsec-&lt;br /&gt;
:-One light year-&lt;br /&gt;
::Oort Cloud (?)&lt;br /&gt;
::Bupkis&lt;br /&gt;
::Comet which will destroy Earth in late 2063&lt;br /&gt;
::Pioneer 10&lt;br /&gt;
::Voyager I&lt;br /&gt;
::Eris (All hail Discordia!)&lt;br /&gt;
::Pluto (Not a planet. Neener neener.)&lt;br /&gt;
::Neptune&lt;br /&gt;
::Uranus&lt;br /&gt;
::Saturn&lt;br /&gt;
::[Two arrows point to two moons, one next to each of the planets above and below.]&lt;br /&gt;
::&amp;lt;-- Life --&amp;gt;&lt;br /&gt;
::Jupiter&lt;br /&gt;
::Asteroids&lt;br /&gt;
::Mars&lt;br /&gt;
::Venus&lt;br /&gt;
::Sun&lt;br /&gt;
::Mercury&lt;br /&gt;
::Spaceship Planet Express: Hey, a heaping bowl of salt!&lt;br /&gt;
::Spaceship Discovery One: Open the fridge door, Hal.&lt;br /&gt;
::Moon&lt;br /&gt;
::Human altitude record (Apollo 13)&lt;br /&gt;
::2nd place: Snoop Dogg&lt;br /&gt;
::Space elevator - One of these days, promise!&lt;br /&gt;
::Geosynchronous Orbit&lt;br /&gt;
::GPS satellites&lt;br /&gt;
::Lunar lander: In retrospect, they &amp;lt;u&amp;gt;shouldn't&amp;lt;/u&amp;gt; have sent a poet. I have no idea how to land.&lt;br /&gt;
::International Space Station&lt;br /&gt;
::Space junk&lt;br /&gt;
:-Official edge of space (100 km)-&lt;br /&gt;
::Meteors&lt;br /&gt;
:-1/10 ATM-&lt;br /&gt;
::High altitude balloons&lt;br /&gt;
::Airliners&lt;br /&gt;
::Shuttle Columbia lost&lt;br /&gt;
:-1/2 ATM-&lt;br /&gt;
::Cory Doctrow&lt;br /&gt;
::Everest&lt;br /&gt;
::Helicopters (6000 m)&lt;br /&gt;
::Cueball: Woo Python!&lt;br /&gt;
::[A vertical scale is drawn along the right side of the picture, starting at 1 km and getting progressivly smaller and smaller.]&lt;br /&gt;
:1 km&lt;br /&gt;
:-800 m-&lt;br /&gt;
::Burj Dubai (~800 m)&lt;br /&gt;
:500&lt;br /&gt;
:400&lt;br /&gt;
::Eiffel Tower (325 m)&lt;br /&gt;
:200&lt;br /&gt;
::Kites&lt;br /&gt;
::Great Pyramid (140 m)&lt;br /&gt;
::Pop fly&lt;br /&gt;
::Redwood (115 m)&lt;br /&gt;
:100m&lt;br /&gt;
::Oak (20 m)&lt;br /&gt;
::A person in the oak: Hey squirrels!&lt;br /&gt;
::Tallest stilts&lt;br /&gt;
::Brachiosaur (13 m)&lt;br /&gt;
::Giraffe (8 m)&lt;br /&gt;
::[Megan and Cueball holding the kite are labeled:] &lt;br /&gt;
::Folks&lt;br /&gt;
:'''The observable universe, from top to bottom'''&lt;br /&gt;
::~On a log scale~&lt;br /&gt;
::Sizes are not to scale, but heights above the Earth's surface are accurate on a log scale. (That is, each step up is double the height.)&lt;br /&gt;
&lt;br /&gt;
==Trivia==&lt;br /&gt;
*A print version of this comic is available in the [https://store.xkcd.com/products/height-poster xkcd store].&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Large drawings]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Comics with inverted brightness]] &lt;br /&gt;
[[Category:Comics featuring Black Hat]]&lt;br /&gt;
[[Category:Comics featuring Cory Doctorow]]&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Space probes]]&lt;br /&gt;
[[Category:Astronomy]]&lt;br /&gt;
[[Category:Space]]&lt;br /&gt;
[[Category:Elevators]] &amp;lt;!--Space Elevator--&amp;gt;&lt;br /&gt;
[[Category:Baseball]]&lt;br /&gt;
[[Category:Animals]]&lt;br /&gt;
[[Category:Dinosaurs]]&lt;br /&gt;
[[Category:Giraffes]]&lt;br /&gt;
[[Category:Squirrels]]  &amp;lt;!--Hi Squirrels in oak tree--&amp;gt;&lt;br /&gt;
[[Category:Programming]] &amp;lt;!--Python--&amp;gt;&lt;br /&gt;
[[Category:Kites]]&lt;br /&gt;
[[Category:Star Trek]]&lt;br /&gt;
[[Category:Comics with xkcd store products]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204725</id>
		<title>2412: 1/100,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2412:_1/100,000th_Scale_World&amp;diff=204725"/>
				<updated>2021-01-15T18:27:54Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: +cat&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2412&lt;br /&gt;
| date      = January 15, 2021&lt;br /&gt;
| title     = 1/100,000th Scale World&lt;br /&gt;
| image     = 1_100000th_scale_world.png&lt;br /&gt;
| titletext = The floor should be slightly curved, but we haven't figured out artificial gravity yet, so for now we just added a trace intoxicating gas to the air that messes with your inner ear and gives you a sense that the ground is tilting away from you.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a TOXIC AURORA. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
This comic is a sequel to the previous comic. There is a 1/100,000th scale world in this comic.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2411:_1/10,000th_Scale_World&amp;diff=204724</id>
		<title>2411: 1/10,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2411:_1/10,000th_Scale_World&amp;diff=204724"/>
				<updated>2021-01-15T18:27:31Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: +cat&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2411&lt;br /&gt;
| date      = January 13, 2021&lt;br /&gt;
| title     = 1/10,000th Scale World&lt;br /&gt;
| image     = 1_10000th_scale_world.png&lt;br /&gt;
| titletext = OCEAN PLAY AREA RULES: No running, no horseplay, no megatsunamis, and no trying to pry the wreck of the Titanic off the bottom.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by a 1/10,000TH SCALE WEATHER BALLOON. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}&lt;br /&gt;
&lt;br /&gt;
Models of large-scale objects (cars, airplanes, etc.) are typically produced at a given scale, given as a ratio between the original object (the first number) and the model (the second number). The same applies to maps and globes. What Randall has here, though, is neither a map nor a model but a seemingly complete copy of Earth, at a 1:10,000 scale. Various features and warnings are labeled.&lt;br /&gt;
&lt;br /&gt;
{{w|Miniature parks}}, also known as model villages, are tourist attractions around the world of a scale between 1:9 and 1:72.  For example, the finale of the movie ''{{w|Hot Fuzz}}'' features a battle amongst a miniature of the streets and buildings seen so far in the film.  Normally a miniature park would feature a representation of one geographical location rather than a geologically/technologically accurate depiction of our current planet. Whether or not Randall is aware of it, the reputed [http://www.mapascotland.org/ largest outdoor relief map in the world] is set out at a horizontal scale of 1:10,000.&lt;br /&gt;
&lt;br /&gt;
Real-world phenomena are reproduced at scale, for humorous effect. A real 1/10,000th scale &amp;quot;Earth&amp;quot; would have a diameter of less than a mile, and a surface area of around 2 square miles, the approximate dimensions of a medium-sized asteroid. On such an object, constrained by known physics, there would be no air, standing water, weather, or large magma bodies, and any sort of rough-housing would irrecoverably catapult the visitor into space.&lt;br /&gt;
&lt;br /&gt;
Normally in a miniature model most warnings try to prevent the visitors from accidentally doing something cataclysmic to the model. Likewise, the &amp;quot;ocean play area rules&amp;quot; in the title text tell visitors not to create any {{w|megatsunami}}s, which could conceivably be induced by a cannonball dive. But as digging seems to be discouraged mainly where it causes volcanoes to break out the visitors seem to be given a far greater freedom than usual.&lt;br /&gt;
&lt;br /&gt;
Visitors are also instructed not to try to pry the model of the {{w|wreck of the Titanic}} off the ocean floor.  In our world, the wreck is at a depth of 12,500 feet, which would be 1 foot and 3 inches in Randall's model world.  The Titanic was over 882 feet long, but the ship split in half as she sank, and now lies in two pieces about a third of a mile apart.  Randall's model would have two pieces about a half-inch in size separated by about two inches.  If the models are rusted and sunk in mud just like the real wreck is, trying to pry them loose would certainly damage them, but all of Randall's other rules seem to be about preventing harm to guests, not preventing damage to the model, so maybe he just doesn't want guests bending over and exerting themselves in water where they could slip, submerge their faces, and be at risk of drowning.&lt;br /&gt;
&lt;br /&gt;
Earlier comics illustrating relative scale include [[482: Height]], [[681: Gravity Wells]], [[1276: Angular Size]], [[1389: Surface Area]], and [[1515: Basketball Earth]].&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
!Rule&lt;br /&gt;
!Reason&lt;br /&gt;
!Notes&lt;br /&gt;
|-&lt;br /&gt;
| Watch out for airliners cruising near shoulder level&lt;br /&gt;
| Unintentional catastrophic damage to air traffic. The damage likely wouldn't be reciprocal: actual airplane speed is very similar to the speed at which a bullet is fired [https://pinchito.es/2019/high-speeds], but 1/10,000 of that is quite slow.&lt;br /&gt;
| At this scale, the lowest airliner cruising altitude would be 3 ft or 0.9 m [https://time.com/5309905/how-high-do-planes-fly/#:~:text=Commercial%20aircraft%20typically%20fly%20between,that%20can%20present%20safety%20issues.], shoulder height for a 5-year-old [https://www.disabled-world.com/calculators-charts/height-weight-teens.php]. Scaling the height of the highest plane to ever fly [https://www.usatoday.com/story/travel/columnist/cox/2017/05/28/altitude/102185856/] puts it at 9 ft, which would put it just over the head of the tallest person who ever lived [https://www.guinnessworldrecords.com/records/hall-of-fame/robert-wadlow-tallest-man-ever]&lt;br /&gt;
|-&lt;br /&gt;
| Trip hazard: Appalachian Mountains&lt;br /&gt;
| At half a foot tall, the Appalachians could trip visitors who are not being careful.&lt;br /&gt;
| 6684 ft ≈ 0.67 ft in model world&lt;br /&gt;
|-&lt;br /&gt;
| Do not stand or climb on Mt. Everest&lt;br /&gt;
| One may destroy the model.&lt;br /&gt;
|Also, Everest appears to be rather pointy. Also still a bit steep, so visitors may fall down and hurt themselves.&lt;br /&gt;
|-&lt;br /&gt;
| Caution: Hydro-thermal vents underfoot&lt;br /&gt;
|Hydrothermal vents are extremely hot, which could cause burns to the feet of the viewers&lt;br /&gt;
|Underwater volcanoes and stuff&lt;br /&gt;
|-&lt;br /&gt;
| Children must be supervised while in the ocean, especially near trenches&lt;br /&gt;
|They might drown.&lt;br /&gt;
|The Challenger Deep is 36,200 feet below the surface; this equates to 3.62 feet in the model world, a depth which small children could conceivably drown in.&lt;br /&gt;
|-&lt;br /&gt;
| Danger: positive lightning! Do not touch cloud tops&lt;br /&gt;
| The cumulonimbus cloud is an electrocution hazard, as Megan is learning the hard way&lt;br /&gt;
| Getting too close to the positive cloud tops risks causing lightning to arc into you down to the negative ground.&lt;br /&gt;
|-&lt;br /&gt;
| Avoid hypoxia by regularly sitting to bring your lungs below the death zone&lt;br /&gt;
| The scale world even has a scale atmosphere, and visitors are cautioned to regularly sit down so they can breathe below the {{w|death zone}}, which is approximately two and a half feet above the surface.&lt;br /&gt;
| The death zone is approximately 8,000 meters above the ground, equating to 0.8 meters or 2.62 feet in the model world. There is also a what if on the subject [https://what-if.xkcd.com/64/].&lt;br /&gt;
|-&lt;br /&gt;
| Do &amp;lt;i&amp;gt;not&amp;lt;/i&amp;gt; dig near Yellowstone&lt;br /&gt;
| Digging up the {{w|Yellowstone Caldera}} could potentially reactivate the {{w|supervolcano}} there.&lt;br /&gt;
|&lt;br /&gt;
|-&lt;br /&gt;
| Please do not smack weather balloons&lt;br /&gt;
| Smacking balloons around can be a fun activity, mostly done by children, but it would be very unfriendly if done to weather balloons.&lt;br /&gt;
| Weather balloons can reach 20 ft in diameter before bursting, corresponding to a 0.6 mm small object at this scale.&lt;br /&gt;
|-&lt;br /&gt;
| Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&lt;br /&gt;
| The {{w|CN Tower}}, the {{w|Space Needle}} and the {{w|Burj Khalifa}} are much taller than they are wide, thus, &amp;quot;pointy&amp;quot;. The Burj Khalifa, the tallest of the three, would stand at 3.2 inches (8.3 cm) at this scale, making it possible to impale one's foot on it when walking&lt;br /&gt;
| [[File:Empire State Building (aerial view).jpg|right|100px|thumb|Pointy.]] This seems to be exclusively for the visitors' benefit, rather than that of the cities.&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
[At the top of the image, inside the panel, a large title is floating in the air.]&lt;br /&gt;
RULES&lt;br /&gt;
&lt;br /&gt;
For visitors to my 1/10,000th scale world&lt;br /&gt;
&lt;br /&gt;
1 meter = 10 km   1 ft = 10,000 ft ~ 2 miles&lt;br /&gt;
&lt;br /&gt;
[Each of the following rules is written near a character or point of interest on the map.]&lt;br /&gt;
&lt;br /&gt;
[Two small dots with thin lines coming out of them horizontally are in the air near [[Cueball]].]&lt;br /&gt;
Watch out for airliners cruising near shoulder level&lt;br /&gt;
&lt;br /&gt;
[Small mountains are seen near the left edge of the screen, by Cueball's feet.]&lt;br /&gt;
Trip hazard: Appalachian Mountains&lt;br /&gt;
&lt;br /&gt;
[Someone is climbing on mountains reaching approximately Cueball's waist.]&lt;br /&gt;
Do not stand or climb on Mt. Everest&lt;br /&gt;
&lt;br /&gt;
[Under the water, a small bump in the ground expells bubbles.]&lt;br /&gt;
Caution: Hydro-thermal vents underfoot&lt;br /&gt;
&lt;br /&gt;
[[[Science Girl]] stands shoulder-deep in the ocean, peering down into the trench below.]&lt;br /&gt;
Children must be supervised while in the ocean, especially near trenches&lt;br /&gt;
&lt;br /&gt;
[[[Megan]]'s hand is extended, and lightning from the cloud is jumping to her hand.]&lt;br /&gt;
Danger: positive lightning! Do not touch cloud tops&lt;br /&gt;
&lt;br /&gt;
[Ponytail sits near some mountains, with a dotted line in the air stretching across her forehead.]&lt;br /&gt;
Avoid hypoxia by regularly sitting to bring your lungs below the death zone&lt;br /&gt;
&lt;br /&gt;
[A blob-shaped thing with wiggly grey texture lines drawn all over is underground.]&lt;br /&gt;
Do &amp;lt;i&amp;gt;not&amp;lt;/i&amp;gt; dig near Yellowstone&lt;br /&gt;
&lt;br /&gt;
[A second Cueball is jumping in the air, a hand reached back, in position to smack a weather balloon.]&lt;br /&gt;
Please do not smack weather balloons&lt;br /&gt;
&lt;br /&gt;
[Some very tiny vertical lines extend from the ground.]&lt;br /&gt;
Be careful not to step on cities with especially pointy towers, like Toronto, Seattle, and Dubai&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Geography]]&lt;br /&gt;
[[Category:Geology]]&lt;br /&gt;
[[Category:Illustrations of scale]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Comics featuring Ponytail]]&lt;br /&gt;
[[Category:Comics featuring Science Girl]]&lt;br /&gt;
[[Category:Comics featuring Hairy]]&lt;br /&gt;
[[Category:Multiple Cueballs]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Category:Illustrations_of_scale&amp;diff=204723</id>
		<title>Category:Illustrations of scale</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Category:Illustrations_of_scale&amp;diff=204723"/>
				<updated>2021-01-15T18:26:02Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: create&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;An occasional recurring theme in xkcd: illustrations of scale.&lt;br /&gt;
&lt;br /&gt;
[[Category:Comics by topic]]&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:2411:_1/10,000th_Scale_World&amp;diff=204668</id>
		<title>Talk:2411: 1/10,000th Scale World</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:2411:_1/10,000th_Scale_World&amp;diff=204668"/>
				<updated>2021-01-14T17:06:38Z</updated>
		
		<summary type="html">&lt;p&gt;Pi one: c&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;&amp;lt;!--Please sign your posts with ~~~~ and don't delete this text. New comments should be added at the bottom.--&amp;gt;&lt;br /&gt;
This sounds like a cool theme for a game jam. [[User:Bwisey|Bwisey]] ([[User talk:Bwisey|talk]]) 07:30, 14 January 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
The comment about airplanes being close to the speed of a bullet in the explanation wouldn't be relevant due to the scale, so they wouldn't be fast compared to the scale of the people here, and with some rough calculations, I think it would take multiple seconds to pass through the thickness of a human body, so if the people were normal properties and the plane moving at its speed being proportional to its scale (thus making its speed seem normal from the perspective of someone shrunk down and on the plane looking at the rate at which it travels compared to its own length or looking at the model surroundings rather than the giant person), it shouldn't cause significant injury.  Granted, as such speeds it wouldn't be able to fly, but the same sort of concerns apply to a lot else here, like the thundercloud and the rate the atmosphere gets thinner at altitude.--[[Special:Contributions/162.158.74.207|162.158.74.207]] 07:54, 14 January 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Also, airplane speed very similar to the speed at which a bullet is fired&amp;quot; - That is true for real world aircraft; it is not at all given for the 1/10000th scale world. (It depends on if time is scaled or just spatial dimensions) [[Special:Contributions/162.158.134.84|162.158.134.84]] 09:59, 14 January 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
The rant about private vs public research seems a tad coat-racky. [[User:Yngvadottir|Yngvadottir]] ([[User talk:Yngvadottir|talk]]) 12:08, 14 January 2021 (UTC)&lt;br /&gt;
: I agree, so I removed it. There's no indication that Randall meant anything more by it than the usually fun activity of playing with balloons would be harmful if done to weather balloons. [[User:Bischoff|Bischoff]] ([[User talk:Bischoff|talk]]) 13:45, 14 January 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
Do disasters in the model have consequences in the real Earth, like in the first row of xkcd #1515? Not being allowed to create megatsunamis or trigger the Yellowstone Supervolcano would support this, but being allowed to step on cities that do not have especially pointy towers would oppose it.[[Special:Contributions/162.158.186.220|162.158.186.220]] 14:07, 14 January 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
This, ladies, gents, and variations thereupon, is the ''xkcd'' I know and love. [[User:Lightcaller|Lightcaller]] ([[User talk:Lightcaller|talk]]) 14:34, 14 January 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
I would really like this on a poster. [[Special:Contributions/172.68.57.33|172.68.57.33]] 16:12, 14 January 2021 (UTC)&lt;br /&gt;
&lt;br /&gt;
Wouldn't an airplane be to the people about twice the speed of a garden snail? [[User:Sarah the Pie(yes, the food)|Sarah the Pie(yes, the food)]] ([[User talk:Sarah the Pie(yes, the food)|talk]])&lt;br /&gt;
&lt;br /&gt;
: I thought comparisons of scale were an oft-revisited theme for xkcd, so was disappointed not to find a category for them; though I tried to list some of them, I didn't find nearly as many of them as I thought there ought to be.  Only just noticed the reference in discussion here to 1515, which kind of supports my suspicion that there are lots I didn't find. --[[User:Pi one|Pi one]] ([[User talk:Pi one|talk]]) 17:06, 14 January 2021 (UTC)&lt;/div&gt;</summary>
		<author><name>Pi one</name></author>	</entry>

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