explain xkcd - User contributions [en]

Talk:2732: Bursa of Fabricius

2023-02-01T20:34:16Z

LunarNapolean: make a comment

One of the reasons for the success of humans is that the tools of humans do not depend on the structure and strength of the human body. Using fire as an example, a single person with a fire stick can burn down an entire forest in a matter of hours. Fire is not limited by the person who started it. The same goes for any other tool we make. ~ [[user:megan|Megan]] <sup>she</sup>/<sub>her</sub> [[user talk:megan|talk]] [[special:contribs/megan|contribs]] 18:35, 1 February 2023 (UTC)

Here's the wiki for Bursa of Frabricius: https://en.wikipedia.org/wiki/Bursa_of_Fabricius

And the wiki for Hieronymus Fabricius: https://en.wikipedia.org/wiki/Hieronymus_Fabricius [[User:Mr. I|Mr. I]] ([[User talk:Mr. I|talk]]) 18:51, 1 February 2023 (UTC)

So ''that's'' why I can't find the Gräfenberg spot! [[User:LunarNapolean|LunarNapolean]] ([[User talk:LunarNapolean|talk]]) 20:34, 1 February 2023 (UTC)

2504: Fissile Raspberry Isotopes

2021-08-19T16:41:48Z

LunarNapolean: Add relation to 2216 "percent milkfat"

{{comic
| number = 2504
| date = August 18, 2021
| title = Fissile Raspberry Isotopes
| image = fissile_raspberry_isotopes.png
| imagesize =
| titletext = Grandma's shelf-stable blackberry pie meson recipe was a huge seller until her farm was shut down by a joint FDA/NRC investigation.
}}

==Explanation==
{{incomplete|Created by a NUCLEAR FARM INVESTIGATOR. Do NOT delete this tag too soon.}}
[[Ponytail]] is admiring her {{w|raspberry}} fields telling [[Cueball]] she expects a good harvest... That is if they do not get too many fissile raspberry isotopes! To which Cueball has to ask ''Too many '''whats?'''''

The comic is thus a joking analogy to {{w|nuclear chain reactions}}, in which the {{w|nuclear fission|fission}} (splitting in two) of one {{w|atomic nucleus}} releases {{w|neutrons}}, which then strike other nuclei and cause them in turn to fission, releasing more neutrons. This chain reaction releases a great deal of energy and is what makes possible both {{w|nuclear power}} and {{w|nuclear bombs}}.

A {{w|fissile isotope}}, such as {{w|uranium-235}}, is one that is sufficiently large and unstable to undergo such a chain reaction, as opposed to the more common and stable {{w|uranium-238}}. Ponytail fear that her raspberries have too many unstable isotopes so that her fields risk undergoing a similar fission-driven chain reaction. This chain reaction is depicted in the second panel, and she explains that if this happens the entire crop may be gone in seconds. It sounds like this is only dangerous for her economy, i.e. all the berries is destroyed, but not the entire field. So not an explosion that destroys her field or any living thing nearby, but the berries would be unsalable.

Of course, in real life raspberries don't do that.{{Citation needed}} As an {{w|aggregate fruit}}, raspberries resemble common depictions of atomic nuclei, with each ovary corresponding to a nucleon (proton or neutron), which is probably why they are the subject of the comic. Perhaps these raspberries are byproducts of the experiments depicted in [[1949: Fruit Collider]].

This comic is also a pun on "pi mesons" or {{w|pions}}, subatomic particles that transmit the {{w|strong nuclear force}}, and the similarity in name to a {{w|pie}}, the food type, as in a {{w|raspberry pie}}. The transmission of the strong nuclear force happens most importantly in the atomic nucleus and is responsible for keeping the nucleus intact, ''i.e.'', preventing it from undergoing fission despite the strong repulsive {{w|electromagnetic force}} present from all the positively-charged {{w|protons}}.

Ponytail claims that her berries are protected (bound) by fresh raspberry pie mesons. Cueball states he hopes they hold, but Ponytail is confident as these pies are made from her grandma's recipe, ''i.e.'', it is actually a fresh pie made from the berries. The faith in the pie recipe being able to impede the danger references the convention of "Just like Grandma used to make", nostalgia for an infallible cookery ancestor, in this case a hallowed family recipe that acts to {{w|Neutron moderator|mitigate}} any budding {{w|Aggregate fruit|'berry'}} chain-reaction.

The title text mentions that the grandma's recipe was a huge seller, but that then the farm was shut down by a joint FDA/NRC investigation. This refers to the {{w|Food and Drug Administration}} (FDA) and the {{w|Nuclear Regulatory Commission}} (NRC). The FDA is responsible for the regulation and inspection of food in the U.S., and the NRC for the regulation and inspection of nuclear facilities and materials. A hypothetical "blackberry pie meson" might well run afoul of both, being both nuclear and therefore subject to NRC regulations and permitting requirements, and unhealthy to eat and thus violating FDA rules. The FDA took a similarly incongruous interest in physics in the title text of [[2216: Percent Milkfat]].

It is mentioned that the pies were {{w|Shelf-stable food|shelf stable}}, which means it can last a long time without being in a refrigerator. This may be because of its innate radioactivity keeping it free from germs. This may also explain why they were shut down by both the above-mentioned agencies.

==Transcript==
:[Ponytail and Cueball are standing in a field, looking at rows of crops disappearing in the distance over rolling hills.]
:Ponytail: I reckon it'll be a good harvest.
:Ponytail: So long as we don't get too many fissile raspberry isotopes.
:Cueball: Too many ''whats''?

:[In a half height panel is show a picture of a raspberry with an arrow to a situation where it is splitting in to two equal parts. From the split there also comes two small ovaries flying out as shown with arrows. Below these two situations is a smaller sketch of how one of these two ovaries will eventually hit another raspberry, which will send out three ovaries when splitting, two of those hitting other berries, that each send out two ovaries. The lower of these are not depicted hitting any, but the upper split hits two again, which each send out two, in an ongoing chain reaction. The depiction stops there. Above this panel is the what Ponytail tells Cueball:]
:Ponytail (narrating): If a raspberry breaks in half, it releases fragments which can cause more splits. Within seconds you've lost the whole crop.

:[Ponytail and Cueball is standing in an empty panel talking.]
:Ponytail: Luckily the berries are bound by fresh raspberry pie mesons.
:Cueball: I hope they hold.
:Ponytail: It's my grandma's recipe. They'll hold.

{{comic discussion}}

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Food]]
[[Category:Nuclear weapons]]

2344: 26-Second Pulse

2020-08-11T16:05:27Z

LunarNapolean: reference hygrometer

{{comic
| number = 2344
| date = August 10, 2020
| title = 26-Second Pulse
| image = 26_second_pulse.png
| titletext = There are some papers arguing that there's a volcanic component, but I personally think they're just feeling guilty and trying to cover the trail.
}}

==Explanation==

In this comic strip, [[Science Girl]] is teaching a class on geology, and explaining some of the non-earthquake signals that seismometers detect. She describes [https://phys.org/news/2011-01-seismometer-noise-south-atlantic-storms.html a mysterious signal that repeats with a 26-second period].
Scientists have exploited this signal to [https://www.researchgate.net/publication/320126150_Assessing_the_short-term_clock_drift_of_early_broadband_stations_with_burst_events_of_the_26_s_persistent_and_localized_microseism correct for clock drift] in historic seismic records.

[[Science Girl]] initially provides a plausible explanation (some kind of natural wave pattern on the coastline of the {{w|Gulf of Guinea}}).
However, she quickly takes a turn for the dramatic when she claims that it might be a giant, murdered by seismologists, whose heart still beats. This is a reference to Edgar Allan Poe's short story ''{{w|The Tell-Tale Heart}}'', in which the main character murders his landlord and hides him beneath the floorboards, and then hears (or believes he hears) his victim's heart continuing to beat; the noise eventually drives the man to confess his guilt to visiting police officers. (The narrator of ''The Tell-Tale Heart'' never uses that phrase in the story; he calls it a ''hideous'' heart.) "The Tell-Tale Heart" was previously referenced in [[740: The Tell-Tale Beat]].

Normal human hearts beat much more rapidly than once every 26 seconds, but [https://www.answers.com/Q/What_animal_has_slowest_heart_rate large animals and hibernating animals] may have much slower heart rates (which would include a giant at the bottom of the ocean).

The title text gives an alternate explanation for the seismic activity: [https://academic.oup.com/gji/article/194/1/362/2006108 volcanic activity], but Science Girl continues to believe in the giant story. In the last panel she references the common science meme that further research is needed, which has been mentioned several times in previous strips, including [[2268: Further Research is Needed]].

A seismometer is a device for measuring vibrations in the earth's crust, and one is likely in the collection of Cueball from [[2060: Hygrometer]].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Science Girl is standing in the front of a whiteboard with a pointer. Ponytail, Hairy, and Megan are sitting at desks.]
:Science Girl: When everything is still, seismometers pick up faint tremors we call seismic noise.
:Science Girl: Most of it is from ocean waves, cars, etc. But there's also a mysterious 26-second pulse.

:[Close up on Science Girl, pointing to a map of the world. Africa is in view, and a star is drawn within the country of Ghana.]
:Science Girl: We've triangulated the source to somewhere in the Gulf of Guinea.
:Science Girl: It comes and goes with the seasons, but it's been there since at least the 1980s. It's so regular we use it to sync up seismometers.

:[Science Girl is shown in profile, with the board behind her.]
:Off-panel voice: What causes it?
:Science Girl: Not sure. The most popular theory is that storm-driven waves set up some kind of resonance with the coast.

:[Science Girl has leaned her stick on the board's tray. She has raised her clenched fists.]
:Science Girl: Another theory is that long ago, seismologists murdered a giant and buried the body at sea.
:Science Girl: Now we are haunted by the beating of its telltale heart!
:Science Girl: Could be either.
:Science Girl: Further research is needed.

{{comic discussion}}
[[Category:Comics featuring Science Girl]]
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Megan]]
[[Category:Geology]]
[[Category:Fiction]]

2344: 26-Second Pulse

2020-08-11T01:00:03Z

LunarNapolean: a -> an

{{comic
| number = 2344
| date = August 11, 2020
| title = 26-Second Pulse
| image = 26_second_pulse.png
| titletext = There are some papers arguing that there's a volcanic component, but I personally think they're just feeling guilty and trying to cover the trail.
}}

==Explanation==
{{incomplete|Created by an OUT-OF-SYNC SEISMOMETER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

{{comic discussion}}

2344: 26-Second Pulse

2020-08-11T00:59:32Z

LunarNapolean: Add "created by"

{{comic
| number = 2344
| date = August 11, 2020
| title = 26-Second Pulse
| image = 26_second_pulse.png
| titletext = There are some papers arguing that there's a volcanic component, but I personally think they're just feeling guilty and trying to cover the trail.
}}

==Explanation==
{{incomplete|Created by a OUT-OF-SYNC SEISMOMETER. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

{{comic discussion}}

Talk:2343: Mathematical Symbol Fight

2020-08-07T20:18:11Z

LunarNapolean:

Can I get aleph-null aleph-shaped throwing stars? [[User:LunarNapolean|LunarNapolean]] ([[User talk:LunarNapolean|talk]]) 20:18, 7 August 2020 (UTC)

1123: The Universal Label

2019-12-06T01:31:10Z

LunarNapolean: Add Category:Thyme

{{comic
| number = 1123
| date = October 19, 2012
| title = The Universal Label
| image = the universal label.png
| titletext = Works for any grocery or non-grocery. Even thyme is just H and time.
}}

==Explanation==
All matter in the universe (heavier than {{w|Isotopes_of_lithium#Lithium-7|lithium-7}}) was created through {{w|nuclear fusion}} of {{w|hydrogen}} atoms inside {{w|stars}} over the 13.8 billion years that have gone by since the {{w|Big Bang}}. A detailed explanation (for the lay person) of this process is available in this article about [http://www.irregularwebcomic.net/3280.html Making Atoms].

From this article (and from the wiki article on Big Bang) it is clear that our universe began not only with hydrogen. Although the majority of atoms produced by the Big Bang were hydrogen, lots of {{w|helium}} and traces of {{w|lithium}} were also produced. Actually {{w|Big_Bang#Abundance_of_primordial_elements|about 25% of the mass}} in the universe comes from helium created shortly after the Big Bang. In stars, however, helium is also created directly from hydrogen atoms. So it would have been enough to just start out with hydrogen in the early universe. Given enough time, all the other elements would have been created inside these originally hydrogen-only stars. To make elements heavier than helium some of the elements created by hydrogen, will have to fuse subsequentially. And in order to make elements heavier than iron, a {{w|supernova}} explosion is needed. But in either case it is still products of hydrogen that fuse together.

In many countries, food products must have their ingredients displayed somewhere on their packaging. Because all the ingredients in any food are either hydrogen or heavier atoms created through stellar nuclear fusion from hydrogen over time, the ingredients of any items can technically be described fully as only being made from hydrogen and time. Thus this label would be the universal label. A pun on two of the meanings of the word [http://en.wiktionary.org/wiki/universal universal]. Any food is of course ''universal'' as in a part of the universe. But the label can also be a ''universal'' label as in a common label for all food or any other product in the universe, as well as the universe itself for that {{w|matter}}.

The title text first makes it clear that this works both for any {{w|grocery}} as well as any non-grocery, which as described above simply means anything else. It then goes on to making a pun on the words {{w|thyme}} (a herb) and {{w|time}}, as the two words are {{w|homophones}}. "H" is the chemical symbol for hydrogen thus completing the pun by noticing that the word "thyme" can be made by adding the letter "h" to "tyme" which would be a homophone even closer to the word time.

[[Randall]] previously made a joke on the fact that thyme and time are homophones in [[282: Organic Fuel]].

==Transcript==
:'''Ingredients:'''
:Hydrogen, Time

{{comic discussion}}
[[Category:Physics]]
[[Category:Language]]
[[Category:Thyme]]

282: Organic Fuel

2019-12-06T01:30:38Z

LunarNapolean: Add Category:Thyme

{{comic
| number = 282
| date = June 27, 2007
| title = Organic Fuel
| image = organic_fuel.png
| titletext = I have nothing to apologize for.
}}
==Explanation==
[[Cueball]] is fascinated about engines that can burn organic matter. But in fact, {{w|biofuel}} is a big industry today. It is criticized now and then, because it can affect food prices and is believed to exacerbate world hunger.

Next comes a reference to the famous quote, "Mussolini made the trains run on time," an oft-quoted piece of [http://www.snopes.com/history/govern/trains.asp propaganda] from Italy under Fascist dictator {{w|Benito Mussolini}}. The pun is made on the fact that {{w|Thyme|thyme}} (an herb, or as in this comic, a spice) and {{w|time}} (the universal phenomenon, as in the original quote) are {{w|homophones}}. But the organic matter thyme could technically be used as fuel.

The title text may be interpreted in one of two ways. It may be attributed to the pun-maker, in which case he makes no apology for his corny joke, or it may be attributed to Cueball, in which case he makes no apology for the termination of friendship, since the pun was too terrible.

[[Randall]] later made another joke on the fact that thyme and time are homophones: [[1123: The Universal Label]].

==Transcript==
:[Cueball at a computer and a friend standing nearby.]
:Cueball: Wow – Engines can burn vegetable oil.
:Friend: Well, sure. You can burn most any organic matter. Corns, leaves, spices...
:Cueball: Spices? Really?
:Friend: Sure – Mussolini made the trains run on thyme.
:Cueball: ...
:Cueball: We are no longer friends.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Thyme]]
[[Category:Puns]]

2231: The Time Before and After Land

2019-12-06T01:28:29Z

LunarNapolean: Add Category:Thyme

{{comic
| number = 2231
| date = November 20, 2019
| title = the Time Before And After Land
| image = the_time_before_and_after_land.png
| titletext = According to Google, "the time for Beeland" is apparently whenever you're looking for delicious honey in Spillimacheen, British Columbia or a hexagonal chalet in the Savinja valley in Slovenia.
}}

==Explanation==
This comic indulges in some wordplay on the title of the 1988 animated movie ''{{w|The Land Before Time (franchise)|The Land Before Time}}'', which takes place millions of years ago in the time of dinosaurs.

The comic shows a timeline of the history of the universe from the {{w|Big Bang}} to the present day, with ''The Land Before Time'' placed at the point in the timeline where the movie is set, as well as other seemingly arbitrary events such as the formation of rocky planets and the evolution of ground-nesting bees. The joke is that Randall has contrived several periods of universal history that sound like funny permutations of "The Land Before Time" due to certain words being {{w|homophone}}s, such as "time" and "thyme", or homonyms, such as the noun "land" (ground) and the verb "land" (to alight). He also split the word "before" into "bee" and "for".

The title text is for the phrase "the time for Beeland" and lists 2 places (that Randall found on Google) with the name "Beeland": [http://beeland.ca/ a market in Spillimacheen, British Columbia] or [http://www.apartmajimozirje.si/en/beeland/ a chalet in Slovenia].

Bees are a [[:Category:Bees|recurring topic]] on xkcd.

===Explanation of time ranges on the chart===

{| class="wikitable"
! Range !! From !! To !! Explanation
|-
|width=15%|'''The time before land'''
|width=10%|Big Bang
|width=10%|Rocky planets form
|width=65%|The {{w|Big Bang}} is a scientific theory that attempts to describe the very earliest conditions in our universe, but is also used informally as a synonym for the beginning of the universe. The early universe contained only simple elements such as hydrogen, but over time, star formation led to the creation of new, heavier elements, which eventually gave rise to planets with a rocky surface, which we call "land". It would have taken billions of years for the first such land-bearing planet to appear in the universe, so this time period could be considered "the time before land".
|-
|'''The time before bees'''
|Big Bang
|Ground-nesting bees evolve
|This time range also includes the formation of the Earth, a necessary precondition for bees to evolve. Any time before the evolution of bees could be considered "The time before bees". While the chart does not account for the possibility that non-ground-nesting bees may have existed prior to ground-nesting ones, evidence strongly suggests that the common ancestor to all bees nested in the ground rather than forming hives.
|-
|'''The land before thyme'''
|Rocky planets form
|''Thymus'' genus diverges
|''Thymus'' is the genus of plant that is called "{{w|thyme}}" in English, and it is pronounced exactly the same way as "time". By "diverges", it is meant that this is the point in time at which the ''Thymus'' genus of plants split off from their ancestral line - ie. when thyme first evolved. This time range is after land first appears in the universe, but before {{w|thyme}} evolved - therefore, any land that existed within this time range can be considered "the land before thyme". When said, this sounds exactly the same as "''The Land Before Time''".
|-
|'''Time for land bees!'''
|Ground-nesting bees evolve
|Now
|When conditions change to allow an event to occur, people sometimes say "time for (event)!". In this case, the event is the emergence of ground-nesting bees, which could be considered "land bees".
|-
|'''Bees land on thyme'''
|''Thymus'' genus diverges
|Now
|Bees are flying insects, and therefore must land in order to rest before taking off again. Now that thyme has evolved, bees are able to land on thyme plants. This is a play on two different meanings of the word "land"; as a noun, it means solid ground, but here, it is a verb which means to alight or stop flying.
|}

==Transcript==
:[Caption at top of panel:]
:(Timeline not to scale)

:[A timeline is shown with two endpoints and five other points. The points are labeled:]
:Big Bang
:Rocky planets form
:Earth forms
:Ground-nesting bees evolve
:''The Land Before Time''
:''Thymus'' genus diverges
:Now

:[Below the timeline are five overlapping time periods in three rows. The text is between two thick black bars. The time periods all start and end at two different points.]

:[Big Bang to Rocky Planets Form:]
:The Time Before Land

:[Big Bang to Ground-Nesting Bees Evolve:]
:The Time Before bees

:[Rocky Planets Form to ''Thymus'' Genus Diverges:]
:The Land Before Thyme

:[Ground-Nesting Bees evolve to Now:]
:Time for Land Bees!

:[Thymus Genus Diverges to Now:]
:Bees Land on Thyme

{{comic discussion}}

[[Category:Timelines]]
[[Category:Fiction]]
[[Category:Bees]]
[[Category:Thyme]]
[[Category:Puns]]