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		<title>explain xkcd - User contributions [en]</title>
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		<updated>2026-06-25T12:32:39Z</updated>
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	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:2750:_Flatten_the_Planets&amp;diff=308736</id>
		<title>Talk:2750: Flatten the Planets</title>
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				<updated>2023-03-16T17:13:15Z</updated>
		
		<summary type="html">&lt;p&gt;172.70.206.187: &lt;/p&gt;
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&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 have to wonder, would you slide down to the sun, or be flung outwards? [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 19:39, 15 March 2023 (UTC)&lt;br /&gt;
: The discs are centered on the orbit of the parent planet, and presumably rotating at the same frequency as the parent planet's orbit.  That means the inner edge of each disc is going slower than you'd need to orbit the Sun at that distance, and the outer edge faster.  If you moved inward from the original planet's orbit, the Sun's gravity would pull you in, but when you crossed the boundary to the next disc, you'd get flung back outward.[[Special:Contributions/162.158.62.61|162.158.62.61]] 19:58, 15 March 2023 (UTC)&lt;br /&gt;
::No Each planet fills out the space within their orbit into the next planet. Easy to see as the outer edge of Neptune's orbit is the same as with the planet flattened. There is a distance from Mercury to the Sun indicated. Maybe because it would melt if it got any closer? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 20:03, 15 March 2023 (UTC)&lt;br /&gt;
:::First, they're rings not discs, but I'm skeptical of the math. And it looks to me like the ring's edges are halfway between the orbits, with Neptune extended outwards the same distance as halfway to Uranus's orbit. [[Special:Contributions/172.69.22.4|172.69.22.4]] 20:08, 15 March 2023 (UTC)&lt;br /&gt;
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{{cot|My mistake, Randall's math is correct, sorry.}}&lt;br /&gt;
&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot; style=&amp;quot;text-align: right;&amp;quot;&lt;br /&gt;
|-&lt;br /&gt;
! Planet !! Volume (10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt; km&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;) !! Orbital radius (10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt; km) || halfway to prior || halfway to next || Annulus area (10&amp;lt;sup&amp;gt;&amp;lt;s&amp;gt;9&amp;lt;/s&amp;gt; ''12'' OOPS!&amp;lt;/sup&amp;gt; km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;) || Thickness (&amp;lt;s&amp;gt;cm&amp;lt;/s&amp;gt; ''10s of microns'')&lt;br /&gt;
|-&lt;br /&gt;
| Mercury || 61 || 58 || 29 (to 0) || 83 || 19,000 || 321&lt;br /&gt;
|-&lt;br /&gt;
| Venus || 928 || 108 || 83 || 129 || 30,637 || 3,029&lt;br /&gt;
|-&lt;br /&gt;
| Earth || 1,083 || 150 || 129 || 189 || 59,942 || 1,802&lt;br /&gt;
|-&lt;br /&gt;
| Mars || 163 || 228 || 189 || 504 || 685,794 || 24&lt;br /&gt;
|-&lt;br /&gt;
| Jupiter || 1,4310,00 || 779 || 504 || 1,107 || 3,051,847 || 46,890&lt;br /&gt;
|-&lt;br /&gt;
| Saturn || 827,130 || 1,434 || 1,107 || 2,154 || 10,726,236 || 7,711&lt;br /&gt;
|-&lt;br /&gt;
| Uranus || 68,340 || 2,873 || 2,154 || 3,684 || 28,061,145 || 244&lt;br /&gt;
|-&lt;br /&gt;
| Neptune || 62,540 || 4,495 || 3,684 || 5,304 (symmetry) || 45,743,348 || 137&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
:::: The volumes in this table are at 2 different scales. Only the Mercury to Mars volumes are at 10&amp;lt;sup&amp;gt;10&amp;lt;/sup&amp;gt; km&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;. Jupiter to Neptune are at 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt; km&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt; [[User:Sandor|Sandor]] ([[User talk:Sandor|talk]]) 21:01, 15 March 2023 (UTC)&lt;br /&gt;
::::: Thanks, fixed; I had the scale wrong for the radii too. [[Special:Contributions/172.71.158.231|172.71.158.231]] 21:16, 15 March 2023 (UTC)&lt;br /&gt;
:::Someone please double-check this, I think Randall is off by a factor of 1000. [[Special:Contributions/172.71.154.229|172.71.154.229]] 21:37, 15 March 2023 (UTC)&lt;br /&gt;
:::: I did my own spreadsheet, and my figures agree with Randall's (roughly). I think your thinkness figures are mostly out by 1000, and a few of your volume figures also have the wrong scale (Mercury is smaller than Mars, and the giants are too big by a factor of 10).  [[User:Sandor|Sandor]] ([[User talk:Sandor|talk]]) 22:07, 15 March 2023 (UTC)&lt;br /&gt;
::::: 61 * 10^9 km^3 is  [https://www.google.com/search?q=61+*+10%5E9+km%5E3+in+cm%5E3 6.1 × 10^25 cm^3], 19000 * 10^9 km^2 is [https://www.google.com/search?q=19000+*+10%5E9+km%5E2+in+cm%5E2 1.9 × 10^23 cm^2], and (6.1 × 10^25 cm^3) / (1.9 × 10^23 cm^2) is [https://www.google.com/search?q=%286.1+%C3%97+10%5E25+cm%5E3%29+%2F+%281.9+%C3%97+10%5E23+cm%5E2%29 3.2 meters]. I'm afraid I'm correct. [[Special:Contributions/172.69.22.145|172.69.22.145]] 22:31, 15 March 2023 (UTC)&lt;br /&gt;
::::: According to {{w|List_of_Solar_System_objects_by_size#Objects_with_radius_over_400_km}} yes I had Mars wrong (corrected) but the others are roughly correct. I stand by my claim that Randall is in error. [[Special:Contributions/172.71.154.86|172.71.154.86]] 22:39, 15 March 2023 (UTC)&lt;br /&gt;
:::::: Mercury's orbital radius is about 58 * 10&amp;lt;sup&amp;gt;6&amp;lt;/sup&amp;gt; km, not 58 * 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt; km, which makes the annulus' area 19000 10&amp;lt;sup&amp;gt;12&amp;lt;/sup&amp;gt; km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;. [[User:Sandor|Sandor]] ([[User talk:Sandor|talk]]) 23:20, 15 March 2023 (UTC)&lt;br /&gt;
::::::: I fixed that label, hold on... [[Special:Contributions/172.71.154.86|172.71.154.86]] 23:30, 15 March 2023 (UTC)&lt;br /&gt;
::::::: You're right. Thanks. Sorry. Reverted on main. [[Special:Contributions/172.71.154.215|172.71.154.215]] 23:39, 15 March 2023 (UTC)&lt;br /&gt;
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|} &amp;lt;!-- {{cob}} --&amp;gt;&lt;br /&gt;
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This makes about as much sense as other Flat Earth theories. [[Special:Contributions/172.70.200.137|172.70.200.137]] 20:00, 15 March 2023 (UTC)&lt;br /&gt;
:But this would actually be a flat Earth. Albeit with a rather larger surface area ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 20:03, 15 March 2023 (UTC)&lt;br /&gt;
:And..the Earth-ring is not a disc and it's also in the same plane as the sun. Meaning If you were to stand on the surface of this ring earth , there would be a perpetual sunrise / sunset... And similar for everything else in the plane of the ecliptic. [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 12:36, 16 March 2023 (UTC)&lt;br /&gt;
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But what does the plot of surface gravity vs distance from the Sun look like? Gravity of an infinite plane and all that?--[[User:Brossa|Brossa]] ([[User talk:Brossa|talk]]) 00:01, 16 March 2023 (UTC)&lt;br /&gt;
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The explanation currently says that it would require &amp;quot;several solar system's worth&amp;quot; of matter, but isn't there enough matter in the actual solar system? --[[User:Purah126|Purah126]] ([[User talk:Purah126|talk]]) 00:49, 16 March 2023 (UTC)&lt;br /&gt;
:That was said in reference to the Alderson Disk, which requires 1000km or so of thickness. Clearly more than the proposal here that gives a minute thickness (relatively) from the ''actual'' planetary mass in the solar system. Even if you reduced its extent (smaller outer, bigger hole for the Sun) it wouldn't thicken up enough. The prior (non-xkcd) version would require a mass of material rivaling, if not exceeding, that of the Sun itself. [[Special:Contributions/172.70.162.222|172.70.162.222]] 02:07, 16 March 2023 (UTC)&lt;br /&gt;
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One of the reasons NASA rejected this could've been the use of inches.  [[Special:Contributions/172.71.102.13|172.71.102.13]] 02:26, 16 March 2023 (UTC)&lt;br /&gt;
: Except for Mars. I can only imagine that use of the metric system for the Mars ring is a reference to the [https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure Mars Climate Orbiter] fiasco, which certainly would not endear Randall, or his proposal, to a NASA granting agency program officer. [[Special:Contributions/172.70.214.150|172.70.214.150]] 02:45, 16 March 2023 (UTC)&lt;br /&gt;
:: I assume the use of microns there is simply because 5/512 is a really awkward fraction. [[Special:Contributions/172.71.223.25|172.71.223.25]] 05:48, 16 March 2023 (UTC)&lt;br /&gt;
::: Awkward? Its vulgar! [[Special:Contributions/172.70.162.56|172.70.162.56]] 08:05, 16 March 2023 (UTC)&lt;br /&gt;
:: Oh right, the Mars Climate Orbiter reference makes sense! I was wondering why Randall would mix imperial and metric units like that. No sane physicist would do that, especially not Randall. [[Special:Contributions/172.71.250.88|172.71.250.88]] 12:52, 16 March 2023 (UTC)&lt;br /&gt;
::: And Randall rubs more salt into the wound by using &amp;quot;micron&amp;quot;, when the formal/correct SI unit name is &amp;quot;micrometer&amp;quot;.[[Special:Contributions/172.70.206.187|172.70.206.187]] 17:13, 16 March 2023 (UTC)&lt;br /&gt;
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If the planets of the solar system were to become disks centered on the respective planet's current orbit, how do we deal with the different orbital eccentricities? For example, per That Other Wiki, Venus has an orbital eccentricity of 0.006772, Earth has 0.0167086, and Mars has 0.0934. Not to mention Neptune's 0.008678 and Pluto's 0.2488; Pluto's orbit actually crosses Neptune's. Surely that would cause issues with the disks? [[Special:Contributions/172.71.98.5|172.71.98.5]] 08:33, 16 March 2023 (UTC)&lt;br /&gt;
:Pluto isn't involved, so at least that difficulty doesn't have to be dealt with. Maybe Pluto and other dwarf planets could be used to supplement the asteroid ball bearings.[[Special:Contributions/172.71.242.63|172.71.242.63]] 10:55, 16 March 2023 (UTC)&lt;br /&gt;
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It appears that there is enough material in the asteroid belt to do this, since a ring of asteroid ball bearings with a 1 trillion kilometer diameter where each ball bearing was a cube 1 meter by 1 meter (clearly more than enough!) would be less than 10 trillion cubic meters. Since the total mass of the asteroid belt is 10^21 kg, and the average density is around 2 g/cm^3, = 2000 kg/m^3, then the amount of matter required is 2,000*10 trillion = 2 quadrillion which is much less than 10^21. (Not sure if this is actually correct) --[[User:Purah126|Purah126]] ([[User talk:Purah126|talk]]) 12:17, 16 March 2023 (UTC)&lt;br /&gt;
:Ahh yes, the classic cubic-bearing. Just what we need in this planetary ring system we've created. Since Randall elects to eschew spheres for the planets, let's go all in and refuse them for the bearings as well. Bravo. ;-) [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 12:40-12:47, 16 March 2023 (UTC) &amp;lt;!-- re'signed' to reflect how it now has separation from the previously following continuation --&amp;gt;&lt;br /&gt;
::''I just want to say that this line of logic ''really'' tickled my funnybone. Well done! ...I've got no other valid contribution at this time, just that.'' [[Special:Contributions/172.70.90.101|172.70.90.101]] 13:11, 16 March 2023 (UTC) &lt;br /&gt;
::That was to further overestimate the material needed, since a cube is more mass than a sphere. --[[User:Purah126|Purah126]] ([[User talk:Purah126|talk]]) 15:09, 16 March 2023 (UTC)&lt;br /&gt;
Did anyone notice that this came out just after pi-day? [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 12:40, 16 March 2023 (UTC)&lt;br /&gt;
: That's really crusty of Randall. It does explain the rolling pin. He probably also knows, and chooses (for cause) not to disclose, that pronunciation of the Greek letter as &amp;quot;pie&amp;quot; [https://www.dude-n-dude.com/2023/03/14/amoebas-lorica-14-march-icymi/ doesn't conform to modern language usage]. [[Special:Contributions/162.158.90.232|162.158.90.232]] 17:01, 16 March 2023 (UTC)&lt;br /&gt;
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== Death's End ==&lt;br /&gt;
&lt;br /&gt;
I don't know if there's a non spoilery-way to mention that there are similar ideas explored in the novel ''Death's End'' by Liu Cixin. [[User:Nedlum|Nedlum]] ([[User talk:Nedlum|talk]]) 13:22, 16 March 2023 (UTC)&lt;br /&gt;
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What would even happen here? Would the rings collapse into planets again? Where will the atmospheres go? Are the rings a uniform material like rock or many small pebbles? What happens at the borders? Would i be squished or will all life still be intact? If i a squished, do i have to put up with my worst enemy next to me? Will it be like the flat skins from //All Tomorrows//? Will i die? I expect to see this in «What If 2» coming out 13th october. [[Special:Contributions/172.68.134.38|172.68.134.38]] 14:31, 16 March 2023 (UTC)&lt;/div&gt;</summary>
		<author><name>172.70.206.187</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=2745:_Obituary_Editor&amp;diff=307242</id>
		<title>2745: Obituary Editor</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=2745:_Obituary_Editor&amp;diff=307242"/>
				<updated>2023-03-05T04:53:02Z</updated>
		
		<summary type="html">&lt;p&gt;172.70.206.187: /* Explanation */ statement that people won't care isn't consistent with statement that there will be no more death -&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 2745&lt;br /&gt;
| date      = March 3, 2023&lt;br /&gt;
| title     = Obituary Editor&lt;br /&gt;
| image     = obituary_editor_2x.png&lt;br /&gt;
| imagesize = 383x232px&lt;br /&gt;
| noexpand  = true&lt;br /&gt;
| titletext = As the editor has reportedly defeated Death in a series of games of skill, no further obituaries are expected.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
{{incomplete|Created by an AUTO-POST SYSTEM - Please change this comment when editing this page. Do NOT delete this tag too soon.}}&lt;br /&gt;
An {{w|obituary}} is a usually short paragraph in a newspaper describing a local person who has recently passed away. They usually offer a few words of praise and a list of a few relatives, as well as a scheduled time for memorial services to be held some time after the obituary is published.&lt;br /&gt;
&lt;br /&gt;
Apparently, the editor of this newspaper's obituary has just died. However, instead of somebody writing their obituary after the fact, as is conventionally done, the editor has seemingly taken matters into their own hands and written their own obituary. They (somewhat vainly) describe themselves as cool, attractive, and universally beloved, a dubious claim at best. The following sentence reveals that the editor had pre-arranged the scheduled release of this obituary, after their death, probably {{w|Dead man's switch|entirely automatically}}. Obituaries are often pre-written for famous people, ahead of their actual need arising, as this (not-so-famous) person has done for themself. Though this is generally to avoid needing to rush the writing of every biography, including carefully ensuring it is accurately written and sufficiently complete, leaving only minor circumstantial updates and detailing to be inserted and checked as and when events lead up to its actual publication.&lt;br /&gt;
&lt;br /&gt;
Rather than the names of some close family (usually parents, a spouse, and children), the editor is allegedly survived by 8 billion people, or the current population of the entirety of Earth, who further are all heartbroken by the loss. All public spaces will now be reserved for a memorial service of the editor every single day (or, at least, the editor hopes they will be). Given that the entire population of earth is unlikely to care about one editor at a local newspaper,{{citation needed}} they are most likely exaggerating the effect which their death will have. &lt;br /&gt;
&lt;br /&gt;
The title text references a common trope in culture, in which a person who has just died decides to challenge Death, or the {{w|Grim Reaper}}, to a game of skill ({{tvtropes|ChessWithDeath|usually chess}}). Apparently, it is (possibly prematurely) claimed by the editor that they have challenged death to a series of games of skill (probably most or all variations of the trope, including chess), and defeated Death in all of them. Rather than gaining themselves a &amp;quot;second chance at life,&amp;quot; however, as is usually the reward promised by Death for the dead person's victory, the editor's victory over Death has been so absolute that Death itself has been nullified for all of humanity. Hence no more obituaries will ever be required, as every human currently alive (and presumably future ones) will now live forever. Of course, if this did actually occur, then the entire population of earth would not be unlikely to care about the editor, because even if the editor's work at the newspaper wasn't significant to them, the editor's role in preventing their deaths would be.  Randall has referenced this trope in [[393: Ultimate Game]], as a tribute to Gary Gygax, the inventor of ''Dungeons and Dragons''.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
{{incomplete transcript|Do NOT delete this tag too soon.}}&lt;br /&gt;
:[Text on the top-left corner of a gray newspaper page:]&lt;br /&gt;
&lt;br /&gt;
:Obituaries&lt;br /&gt;
:&amp;lt;hr width=&amp;quot;50&amp;quot; style=&amp;quot;background-color:black&amp;quot; align=&amp;quot;left&amp;quot;&amp;gt;&lt;br /&gt;
:The cool, attractive, universally beloved&lt;br /&gt;
:editor of the obituary section has died,&lt;br /&gt;
:hopefully of natural causes after a long&lt;br /&gt;
:life.  They take with them the password to the&lt;br /&gt;
:heretofore unrevealed auto-post system.&lt;br /&gt;
&lt;br /&gt;
:They are survived by 8 billion heartbroken&lt;br /&gt;
:people.  Memorial services will be held&lt;br /&gt;
:daily in all public spaces from now on.&lt;br /&gt;
:&amp;lt;hr width=&amp;quot;50&amp;quot; style=&amp;quot;background-color:black&amp;quot; align=&amp;quot;left&amp;quot;&amp;gt;&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;/div&gt;</summary>
		<author><name>172.70.206.187</name></author>	</entry>

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