explain xkcd - User contributions [en]

Talk:2172: Lunar Cycles

2022-12-18T02:44:47Z

EnderPlays:

Is it just me or is the square-circle moon cycle a reference to Minecraft? [[User:EnderPlays|EnderPlays: Joined 29 April 2021]] ([[User talk:EnderPlays|talk]]) 02:44, 18 December 2022 (UTC)

Is it possible that the size of the Earth and the moon are supposed to be comparisons of how big the Earth looks from the moon vs. how big the moon looks from the Earth? {{unsigned ip|172.69.170.88}}
:Why would that have a cycle different from the distance cycle?[[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:20, 5 July 2019 (UTC)

Where is the total eclipse of the heart?
Actually, why do we not have a total eclipse of the hart - when all deer are hidden?

A very quick and dirty (probably flawed, until I can plug things into a suitable visualiser to check and/or improve my initial idea) attempt to describe the nature of the square/circle oscilations of the Moon might well be smething like ''|r.cos(θ)−r.sin(θ)|.|sin(t/λ)| + |r.cos(θ)+r.sin(θ)|.|sin(t/λ)| + |r.√(2/π)|.|cos(t/λ)|=k'' ...only then you'd also want to make k a quantity also multiplied by the relative Earth/Moon size cycle. Either way, YMoonMV. [[Special:Contributions/141.101.98.88|141.101.98.88]] 00:41, 6 July 2019 (UTC)
:Isn't the square/circle a reference to rounded corner rectangles. If you increase the corner radius of a square, enough, you get a circle. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 05:37, 6 July 2019 (UTC)

Does anyone know of a real chart similar to the format of the last panel? That might be a cool thing to link to.
[[Special:Contributions/162.158.75.166|162.158.75.166]] 16:38, 6 July 2019 (UTC)

Did anyone else expect to see "Total Eclipse of the Heart" right after "Total Eclipse of the Sea"? No? Ah, my coat, thank you.[[User:Daemonik|Daemonik]] ([[User talk:Daemonik|talk]]) 09:17, 8 July 2019 (UTC)

I refer the honourable gentleman to the answer I gave earlier [[Special:Contributions/162.158.154.67|162.158.154.67]] 20:10, 8 July 2019 (UTC)

I remember there being a blue blood supermoon or some crazy thing like that once a year or so back. Mostly because I dreamed that it was also a falling moon and woke up very worried. --[[Special:Contributions/162.158.58.169|162.158.58.169]] 00:18, 12 July 2019 (UTC)

== Astrology ==
I think this is primarily an astrology joke. Astrologers often use astronomical cycles (both real and made up) to "predict" future events or explain historic events. By having enough cycles, they can usually come up with results like "skinny jeans are always popular whenever the happy moon is in Pices and wet Mars is in the same Chinese zodiac as Mercury".

There's also possibly an allusion to Fourier transforms. {{unsigned ip|162.158.92.160|03:14, July 6, 2019‎}}

You know, I kind of expected a joke about periods [[Special:Contributions/172.69.160.146|172.69.160.146]] 01:49, 10 July 2019 (UTC)

I think this is unlikely - the jokes all hinge on cycles of the moon, and don't reference any dates or other celestial bodies in the way astrology does.
[[Special:Contributions/162.158.154.37|162.158.154.37]] 12:33, 8 July 2019 (UTC)

==Phase x distance and supermoons==
I've been absolutely nerd-sniped by the "Phase x distance" in the bottom diagram. As far as I can figure out, if you multiply phase and distance, you should end up with a new cycle with a period of (29.5 x 27.5) = 811.25 days, which is about 2 years. A supermoon is when a full moon occurs when the Moon is closest to the Earth, so this phase x distance figure is effectively a supermoon detector - that's why supermoons occur at the peaks in Randall's diagram.

But when I looked into supermoons a bit - specifically [https://en.wikipedia.org/wiki/Supermoon#/media/File:Moon_distance_with_full_&_new.png this diagram from Wikipedia] - other sources shows supermoons occurring on a ''yearly'' cycle - we supposedly get them every year. How can that be the case, if the two lunar cycles only synchronize every 2 years? It seems to me like there has to be at least one out of every two years where we get no supermoons at all - ie. the full moon is always coinciding with the moon being furthest away.

I feel like I must have made a mistake or wrong assumption, but I can't figure out what it is. [[User:Hawthorn|Hawthorn]] ([[User talk:Hawthorn|talk]]) 17:15, 6 July 2019 (UTC)
:I figured it out; it turns out that I was simply wrong about how to calculate the length of a combined cycle. This [https://www.desmos.com/calculator/vaj4vapdul graph] shows that the two cycles would coincide every 400 days or so. Still can't figure out what "phase x distance" is meant to represent, though. [[User:Hawthorn|Hawthorn]] ([[User talk:Hawthorn|talk]]) 17:54, 6 July 2019 (UTC)

== Earth/Moon changing size ==
While I do know that the Earth and Moon can technically change size due to accretion of interstellar material, the amount is so negligible that I don't even think it's worth mentioning. I suspect the Earth changes size more from thermal expansion and contraction than from accretion. [[User:Hawthorn|Hawthorn]] ([[User talk:Hawthorn|talk]]) 13:03, 9 July 2019 (UTC)

==Harvest Moon==
The harvest moon does have some astronomical significance: the time of moon-rise from day to day changes less around the harvest moon than at any other time of the year. [https://en.wikipedia.org/wiki/Full_moon#Harvest_moon Wikipedia] and its [http://calgary.rasc.ca/sunset_moonrise.htm source] say that this allowed harvest work to continue into the night during the days after the full moon without a significant period of darkness between sunset and moon-rise. [[Special:Contributions/172.68.189.85|172.68.189.85]] 05:59, 10 July 2019 (UTC)

2700: Account Problems

2022-11-18T23:45:01Z

EnderPlays: Added transcript.

{{comic
| number = 2700
| date = November 18, 2022
| title = Account Problems
| image = account_problems_2x.png
| imagesize = 538x272px
| noexpand = true
| titletext = My password is just every Unicode codepoint concatenated into a single UTF-8 string.
}}

==Explanation==
{{incomplete|Created by a ZERO WIDTH SPACE- Please change this comment when editing this page. Do NOT delete this tag too soon.}}
[[Cueball]] walks toward [[Ponytail]] carrying his laptop. Ponytail is sitting at her desk, and turns to face him. Having attempted to fix Cueball's computer problems before, she replies with dread.

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

:[Cueball walks up to Ponytail.]
:Cueball: Can you help me with my account?
:Ponytail: Oh no.
:Cueball: No, no, I promise it's a normal problem this time.
:Ponytail: Okay, fine, what is it?
:Cueball: I included a null string character as part of my password, and-
:Ponytail: How?!
:Cueball: They said to use special characters!

{{comic discussion}}

Main Page/sandbox

2022-11-17T01:45:33Z

EnderPlays:

If you get to this sandbox page, say hi! —[[User:EnderPlays|EnderPlays]] October 11, 2022
:Hi —[[User:While False|While False]] ([[User:While False/explain xkcd museum|'''museum''']] | [[User talk:While False|talk]] | [[special:Contributions/While_False|contributions]] | [[special:Log/While_False|logs]] | [[Special:UserRights/While_False|rights]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi
:Hi! [[User:Netherin5|“That Guy from the Netherlands”]] ([[User talk:Netherin5|talk]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi! {{User:PoolloverNathan/Signature}} {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:hi! [[User:JLZ0kTC5|JLZ0kTC5]] ([[User talk:JLZ0kTC5|talk]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi! [[Special:Contributions/172.69.68.22|172.69.68.22]] {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)Bumpf
:Hi again? Random is [[Special:Random|weird]]. {{User:PoolloverNathan/Signature}} 14:24, 14 November 2022 (UTC)
:Yea, random brought me back here too lol. {{User:EnderPlays}} 01:43, 17 November 2022 (UTC)
Hi [[Special:Contributions/172.70.230.159|172.70.230.159]] {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)

Main Page/sandbox

2022-11-17T01:43:06Z

EnderPlays:

If you get to this sandbox page, say hi! —[[User:EnderPlays|EnderPlays]] October 11, 2022
:Hi —[[User:While False|While False]] ([[User:While False/explain xkcd museum|'''museum''']] | [[User talk:While False|talk]] | [[special:Contributions/While_False|contributions]] | [[special:Log/While_False|logs]] | [[Special:UserRights/While_False|rights]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi
:Hi! [[User:Netherin5|“That Guy from the Netherlands”]] ([[User talk:Netherin5|talk]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi! {{User:PoolloverNathan/Signature}} {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:hi! [[User:JLZ0kTC5|JLZ0kTC5]] ([[User talk:JLZ0kTC5|talk]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi! [[Special:Contributions/172.69.68.22|172.69.68.22]] {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)Bumpf
:Hi again? Random is [[Special:Random|weird]]. {{User:PoolloverNathan/Signature}} 14:24, 14 November 2022 (UTC)
:Yea, random brought me back here too lol. 01:43, 17 November 2022 (UTC)
Hi [[Special:Contributions/172.70.230.159|172.70.230.159]] {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)

Main Page/sandbox

2022-11-09T20:51:34Z

EnderPlays: change date to correct

If you get to this sandbox page, say hi! —[[User:EnderPlays|EnderPlays]] October 11, 2022
:Hi —[[User:While False|While False]] ([[User:While False/explain xkcd museum|'''museum''']] | [[User talk:While False|talk]] | [[special:Contributions/While_False|contributions]] | [[special:Log/While_False|logs]] | [[Special:UserRights/While_False|rights]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi
:Hi! [[User:Netherin5|“That Guy from the Netherlands”]] ([[User talk:Netherin5|talk]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi! {{User:PoolloverNathan/Signature}} {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:hi! [[User:JLZ0kTC5|JLZ0kTC5]] ([[User talk:JLZ0kTC5|talk]]) {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)
:Hi! [[Special:Contributions/172.69.68.22|172.69.68.22]] {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)Bumpf
Hi [[Special:Contributions/172.70.230.159|172.70.230.159]] {{CURRENTTIME}}, {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}} (UTC)

Main Page/sandbox

2022-10-19T18:17:08Z

EnderPlays: Fixed comment formatting v2

Main Page/sandbox

2022-10-19T18:15:45Z

EnderPlays: Fixed comment formatting

Main Page/sandbox

2022-10-18T13:11:32Z

EnderPlays: Added a comment.

EnderPlays: If you get to this sandbox page, say hi!

2681: Archimedes Principle

2022-10-05T22:54:53Z

EnderPlays: Added the transcript.

{{comic
| number = 2681
| date = October 5, 2022
| title = Archimedes Principle
| image = archimedes_principle_2x.png
| imagesize = 312x379px
| noexpand = true
| titletext = "I've always wanted to run naked through town, but I don't want to get in trouble with the king or be remembered by history as a weirdo. I wonder how I could ... EUREKA!"
}}

==Explanation==
{{incomplete|Created for a heist - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Megan is seen picking up a crown from a bucket filled with water, while Archimedes is writing at a desk.]
:Megan: Uh, Archimedes, why is there a bucket of water with a gold crown hidden in the bottom?
:Archimedes: It's mostly silver. Replica of the King's crown. He's coming here later, and I have a plan.

:[Caption beneath the panel:]
:Archimedes invents the heist.

{{comic discussion}}

1658: Estimating Time

2022-05-26T17:52:33Z

EnderPlays: This page was vandalized on may 26 12:53 2022, so i replaced the text with this.

This page is being rebuilt after vandalizing happened here.

2114: Launch Conditions

2022-05-26T17:52:08Z

EnderPlays: This page was vandalized on may 26 12:54 2022, so i replaced the text with this.

This page is being rebuilt after vandalizing happened here.

New York Times: Good Question

2022-05-26T17:49:23Z

EnderPlays: This page was vandalized on may 26 13:04 2022, so i replaced the text with this.

This page is being rebuilt after vandalizing happened here.

1551: Pluto

2022-05-26T17:48:51Z

EnderPlays: This page was vandalized on may 26 13:04 2022, so i replaced the text with this.

This page is being rebuilt after vandalizing happened here.

2423: Project Orion

2021-04-29T23:40:02Z

EnderPlays: I add the phrase "which also uses nuclear energy" to the title text.

{{comic
| number = 2423
| date = February 10, 2021
| title = Project Orion
| image = project_orion.png
| titletext = If you tune out again, when you tune back in you'll be hearing about dusty plasma fission fragment rockets.
}}

==Explanation==

{{incomplete|Created by a FADED PHYSICIST. More on the title text. Do NOT delete this tag too soon.}}

[[White Hat]] and [[Cueball]] are having a conversation. In the first panel, Cueball is telling White Hat about his gardening experiences. White Hat tunes out for the middle two panels, and when he starts paying attention again, Cueball is discussing {{w|Project Orion (nuclear propulsion)|Project Orion}}.

Project Orion was an ambitious idea, funded briefly by the US government in the 1960s, to launch enormous spaceships into orbit by detonating a series of nuclear bombs below them. The force from the explosions would be absorbed by a pusher plate on the bottom of the rocket, which is the detail Cueball is sharing when White Hat tunes back in. In {{w|Ad Astra (film)|''Ad Astra''}}, Roy McBride uses a similar mechanism to get from Neptune back to Earth. It was considered feasible for construction, but abandoned because of the 1963 {{w|Partial Test Ban Treaty}} as well as out of concerns for both cost and the idea of spaceships literally armed with atomic bombs. People probably daydream about this project because it seems like it could provide for rapid and massive entry into space, but it was halted due to the intense danger. We may have sufficient technology to somehow make this safe with extensive additional engineering, but the risk is still so large it has not been pursued.

The fact that physicists' conversations tend to converge towards Project Orion is similar to how Randall's conversations tend to converge towards carcinization in [[2418: Metacarcinization]]. Cueball turned into a crab (i.e., he carcinized) when Megan first told him about carcinization in [[2314: Carcinization]]; hopefully physicists don't do something analogous when discussing Project Orion.

The title text transitions to another cool nuclear rocket technology, [http://www.projectrho.com/public_html/rocket/enginelist2.php#fissionfragment dusty plasma fission fragment rockets], which also uses nuclear energy, and would fit well in the [[2326: Five Word Jargon]] collection.

Project Orion has been mentioned before, in [[786: Exoplanets]], where Beret Guy sums it up as "nuke-riding city ships", and on [https://what-if.xkcd.com/7/ what if?].

==Transcript==
:[Cueball is raising his arm, holding the hand tilted down with palm up towards White Hat. Above them is the words Cueball says (without a speech line showing this). The first three lines are in normal font, but then successive lines fade to lighter and lighter gray and finally in the fourth line, just above their heads, the text is almost white. The overall effect is that Cueball's words gradually become background noise to White Hat.]
:Cueball: Our garden grew really well last year, so we think we might put a second raised bed along the garage, if we can find a...

:[Only White Hat is shown, without text, as he stares away from where Cueball must be off the edge of the panel.]

:[Only White Hat again, who now seems to look straight out of the panel.]

:[Back to the original setting. Cueball has lifted both hands up in front of him. He once again has the attention of White Hat. The text above begins with a line half hidden under the top of the panel, almost white font, and then the text fades back to black font over the next three lines, with the next, and last, line in his first paragraph all in black. And then a small gap and connecting line between this and the last two lines of text in his second paragraph. This time there is also with a speech line down to Cueball. The text from "..." to the first comma is difficult to read as only bottom half is shown, and in very faded font.]
:Cueball: ...thanks to X ray ablation, the pusher plate would absorb the nuclear blast, recoil, and then return to position for the next bomb.
:Cueball: Such a wild idea! Probably good that it was abandoned.

:[Caption below the panel:]
:If you temporarily tune out while a physicist is talking, when you tune back in they'll be talking about Project Orion.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Physics]]
[[Category:Space]]
[[Category:Convergence]]

588: Pep Rally

2021-04-29T13:53:45Z

EnderPlays: I removed the comma from "Why are we doing this, rally".

{{comic
| number =588
| date =May 25, 2009
| title =Pep Rally
| image =pep_rally.png
| titletext =You know, pep rallies weirded me out in high school, and they've only gotten creepier in retrospect.
}}

==Explanation==
{{incomplete|The title text isn't explained properly.}}
Any American who went to high school remembers the convocations they had during {{w|High school football|football}} or basketball season, in which class would be interrupted and everyone was crowded into the gymnasium for a {{w|pep rally}}. Cheerleaders would cheer, they'd play the school fight song, the {{w|Cheerleading|cheerleaders}} might do a routine, and the team would be introduced.

This is used to inspire {{w|school spirit}} and get people excited about attending the games so that they'd come to the games and spend money on tickets and concessions. A common boast at pep rallies is "Our school is the best!"

"Wait, why?" says one of the students, quite logically. Why is ''their'' school the best? The student population is simply made up of students living in the general ZIP code of the school's location. There's no intrinsic reason why ''any'' school is any better than the rest of them in any way that really matters in real life. And even having the #1 basketball or football team in the state doesn't mean the students in that school are any "better" than anyone else.

This comic subverts the usual expectation of unanimous agreement with the cheerleader's sentiment, and reminds you that people who go to other schools or root for other teams aren't "bad people". In fact, they are capable of being quite kind as is demonstrated by the North High football team who helped rebuild someone's deck, the principal who donated his kidney, and the welcoming invitation from one of the student's friends to his school's events. [[Randall]] would no doubt argue that this is the same of people who follow a different religion than you, are of a different ethnicity, or have a different political party affiliation.

The title text says that Randall was weirded out by pep rallies growing up, as many introverted people do because of the noise and excitement. Now that he's older, he finds them even ''more'' creepy, probably in retrospect of all the weird stuff in the pep rallies.

==Transcript==
:[Ponytail stands in front of crowded bleachers (with only Cueballs in it), waving pompoms high in the air.]
:Ponytail: Lakeview High is the best!
:Crowd: Yeah!
:Voice #1: Wait, why?

:[Zoom on Ponytail, now with her hands and pompoms down.]
:Ponytail: What?
:Voice #1 (off-screen): A guy on the North High football team helped me rebuild my deck.
:Voice #1 (off-screen): It seems ungrateful to presume we're better.

:[Same picture with Ponytail now just listening.]
:Voice #1 (off-screen): I mean, school districts are just based on zip codes.
:Voice #2 (off-screen): Their principal donated a kidney to my dad.

:[Ponytail looks down, holding up her pompoms.]
:Voice #1 (off-screen): I'm texting with my friend there now. He says it's okay, and we're invited to their events if we want.
:Voice #1 (off-screen): But he sounded kind of hurt.
:Voice #2 (off-screen): Why are we doing this rally, again?

{{comic discussion}}

[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]
[[Category:Sport]]