explain xkcd - User contributions [en]

2646: Minkowski Space

2022-07-16T12:34:43Z

172.68.132.108: /* Explanation */ copyedit

{{comic
| number = 2646
| date = July 15, 2022
| title = Minkowski Space
| image = minkowski_space.png
| titletext = My liege, we were able to follow the ship into Minkowski space, but now they've jumped to Hilbert space and they could honestly be anywhere.
}}

==Explanation==
{{incomplete|Created by A RELATIVISTIC QUANTUM STATE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

A spaceship is being pursued by an enemy ship. Much like in [[2577: Sea Chase]], it attempts to escape by changing the nature of the space. In this case, it goes into {{w|Minkowski space}}, a mathematical formulation of three dimensional space combined with the dimension of time to form a {{w|manifold}} originally intended to help describe {{w|electromagnetism}} in terms of {{w|special relativity}}, and which is also used in {{w|general relativity}}.

Minkowski space is no different than ordinary spatiotemporal physical reality, so the idea of traveling from regular space into Minkowski space is meaningless, providing the humor of the comic's absurdist joke. The visual depiction of the spaceships skewed diagonally is based on the graphical {{w|Minkowski diagram}} representation of objects in Minkowski space, where the {{w|world line}} of matter is bounded inside its diagonal {{w|light cone}}.

The mention of distance depending on the observer's frame of reference refers to distances changing when measured in different {{w|inertial frame of reference|inertial frames of reference}}, a concept called the {{w|relativity of simultaneity}}. Here are [https://www.youtube.com/watch?v=asW78vToNLQ some videos] intended [https://www.youtube.com/watch?v=Xrqj88zQZJg to explain] that concept. The skewing depicted changes the distance between the spaceships in such a way that the tip of the pursuer comes closer to the pursued spaceship, but their centers move further apart. So the question of whether they have come closer is indeterminate for the reader of the comic.

The title text is a message told by someone in the pursuing spaceship to their leader (whom they call "my liege.") They tell their superior that following the spaceship to Minkowski space was not a problem, but now they cannot find them after they jumped to Hilbert space, as they could now be anywhere. As in the Sea Chase comic, there was also more than one type of space to jump to here.

Whereas trying to hide in Minkowski space failed, it turned out that hiding in {{w|Hilbert space}} is much easier. This is because Hilbert spaces can have an infinite number of dimensions, and thus are much more complicated than four-dimensional Minkowski space. However, Hilbert space is used to describe mathematical objects such as functions of various parameters and complexity, not physical spatiotemporal reality, so it is very unusual for a physical object to be represented in Hilbert space. The reference to Hilbert space could also relate to the {{w|uncertainty principle}}, as quantum states can be represented as vectors in a Hilbert space.

==Transcript==
:[A spaceship is being pursued by another spaceship. Both ships have a black part in the front representing a window. They are the same size but different designs. The pursued spaceship to the right has two engines below and a big engine behind. The pursuing spaceship to the left has a V-shaped rear end, and what seems like two weapons on either side pointing forward. At least two persons inside the pursued spaceship are talking to each other, and their text comes out from two starburst on top and bottom of the spaceship.]
:Voice 1: The enemy ship is right behind us!
:Voice 2: Prepare to jump to Minkowski space on my mark.

:[Same setting, with star burst above only. The sound coming from the pursued spaceship is written inside a burst of small lines below the spaceship. It is not possible to say how many different persons are inside the pursued spaceship, but voice 2, must be the same in panel 1 and 2. But not necessarily the same as in the first two panels in the final panel.]
:Voice 2: Three... two... one... ''mark!''
:Click

:[Both spaceship are tilted upwards and becomes distorted so they become longer and thinner.]

:[The tilting increases and the distortion is now so pronounced that the spaceships are almost unrecognizable, almost just lines with structure. The distance between the tip of the pursuing spaceship and the pursued becomes shorter in the last two panels, but the distance between their center parts becomes larger.]
:Voice 3: Are they still getting closer?
:Voice 4: I can't tell.
:Voice 5: I think it depends on your frame of reference.

{{comic discussion}}

[[Category:Space]]
[[Category:Math]]
[[Category:Physics]]

2645: The Best Camera

2022-07-13T17:07:09Z

172.68.132.108:

{{comic
| number = 2645
| date = July 13, 2022
| title = The Best Camera
| image = the_best_camera.png
| titletext = The best camera is the one at L2.
}}

==Explanation==
{{incomplete|Created by an AMATEUR PHOTOGRAPHER - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

The first pictures taken by the James Webb Space Telescope were recently released. The title text references Lagrange Point 2, the location of the aforementioned telescope and one of the 5 regions in space where something can be stationary relative to the earth and sun. L2, specifically, is the umbra of the shadow cast by the earth and sun, which makes it a good place for telescopes to avoid the sun’s glare.

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

{{comic discussion}}

Talk:2631: Exercise Progression

2022-06-11T21:43:56Z

172.68.132.108: Post question

The bot appeared to have not created the page, so I created it- apologies for any mishaps that I might've caused as a result. [[User:Char Latte49|Wielder of the Staple Gun]] ([[User talk:Char Latte49|talk]]) 02:42, 11 June 2022 (UTC)

I replaced the comic image, which was the 2x size image, with the correct size image from XKCD. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 03:07, 11 June 2022 (UTC)

;"[https://www.explainxkcd.com/wiki/index.php?title=2631:_Exercise_Progression&oldid=286674 CRAPDALIZER]"?
Witw is a crapdalizer? [[Special:Contributions/172.70.126.221|172.70.126.221]] 03:42, 11 June 2022 (UTC)
:I would guess WotSG couldn't think of what to put there and made up a silly nonsense word. It's also an anagram of "lizard caper"... Anyway, I've changed it to something a bit more relevant. (Not sure if I should have deleted the "Please change this comment" part as well.)[[Special:Contributions/172.70.174.159|172.70.174.159]] 05:02, 11 June 2022 (UTC)
::Sounds like more of the crapper syndrome we have had. It is confusing with such a comment here, when the word is removed from the explanation, so I have [https://www.explainxkcd.com/wiki/index.php?title=2631:_Exercise_Progression&oldid=286674 linked to a version] of the explanation with the word in place in the incomplete reason. Also please do not add sections in the talk page... --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 08:23, 11 June 2022 (UTC)
:It was by an anonomous user, I tried to remove it but they reverted and it wasn't major enough to warrant an edit war [[User:Char Latte49|Wielder of the Staple Gun]] ([[User talk:Char Latte49|talk]]) 17:33, 11 June 2022 (UTC)
Surprised that there was STILL no Explanation or Transcript at 2am EST, so since I fully understand this one (I feel like I wrote this comic, LOL!) I gave it a shot. '''I''' feel like they're complete and thorough, but last time my writing was completely replaced, LOL! [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 06:17, 11 June 2022 (UTC)

I was a nerd, but discovered exercise around 2012 and became very active. After the social media political stuff around 2013-2016, my curve shifted from the normal one to Randall's, incredibly hard to do things other than what's supported by the patterns. I don't think Randall's curve is natural, I think he was hit by the influence stuff too. [[Special:Contributions/172.70.110.121|172.70.110.121]] 11:05, 11 June 2022 (UTC)
:My solution has been that I didn't increase the difficulty. I found a level I was comfortable with and don't whine about it. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 12:55, 11 June 2022 (UTC)

I never heard of this "up to six months" rule of thumb. Can someone add a citation or remove it? --[[Special:Contributions/172.68.132.108|172.68.132.108]] 21:43, 11 June 2022 (UTC)

2626: d65536

2022-05-31T02:02:54Z

172.68.132.108: Added description of title text, long time reader first time editor. Sorry If I made any mistakes.

{{comic
| number = 2626
| date = May 30, 2022
| title = d65536
| image = d65536.png
| titletext = They're robust against quantum attacks because it's hard to make a quantum system that large.
}}

==Explanation==
{{incomplete|Created by a HEXAKISMYRIAPENTAKISCHILIAPENTAHECTATRIACONTAKAIHEXAHEDRON DICER, NEEDS MORE - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
In binary computing, 16 bit numbers range from 0 to 65535 (or 1 to 65536). Generating large numbers randomly is a recurring problem in cryptography.

In board games and other tabletop games, dice are referred to as d[number] according to their number of sides. A traditional six-sided die would be a d6. Dice larger than a d20 are rare specialty dice, and are often nicknamed "golf balls" to emphasize how unwieldy they are.

Here, Cueball has somehow constructed a d65536 for generating random 16 bit numbers. It has solved the problem of being secure from a cryptography standpoint, but presents a new set of challenges from its sheer size, dwarfing an average human. While large in itself, a die that big could still be emulated by rolling multiple dice (e.g. 8 4-sided dice or 16 coin flips) and converting the result into binary before getting the desired number.

The closest regular shape similar to the depicted in the comic could be a {{w|Goldberg polyhedron}}. However no such polyhedron exists with exactly 65536 hexagonal faces. The closest Goldberg Polyhedron has a mixture of 65520 hexagons and 12 pentagons, totaling 65532 sides.

The title text references how many cryptographic systems (especially RSA and other factoring-is-hard based systems) are hypothetically vulnerable to quantum attacks if we could build quantum computers large and coherent enough to actually compute on more than a few qubits. The title text is essentially punning on the idea of a "large" quantum system. "Large" in the quantum computing sense would be on the order of 64 qubits each of which would be an atom or two at most. This would still be microscopic and will never be as large as the giant die the comic is centered on.

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

[Drawing of a large die with many sides, about ten meters in diameter; Cueball is standing next to it as a size reference. A small portion of the die's surface is zoomed in, showing hexagonal faces with five-digit numbers.]

[Text below the drawing:]
The hardest part of securely generating random 16-bit numbers is rolling the d65536.

{{comic discussion}}

[[Category:Cryptography]]

2614: 2

2022-05-03T08:41:27Z

172.68.132.108: reverting vandalism

{{comic
| number = 2012
| date = Doug Walker, 2012
| title = Nostalgic Critique
| image = Doug Walker in 2012.jpg
| titletext = Hello, I'm the Nostalgia Critic, I remember it so you don't have to.
}}
https://channelawesome.com/category/videos/channelawesome/dougwalker/nostalgia-critic/
https://wiki.soyjak.party/index.php?title=Fingerboys

==Explanation==
{{incomplete|Created by 2 squared - Please change this comment when editing this page. The titletext needs to be worked in there, but I think I got everything else in some sort of order, pending general improvements. Do NOT delete this tag too soon.}}

'''The Nostalgia Critic''' is an American review comedy web series created, directed by and starring web comedian Douglas "Doug" Walker. The series initially launched on YouTube on July 3, 2007, before moving to Walker's own site, That Guy with the Glasses, then to Channel Awesome. The show follows Walker as the title character, a bitter and sarcastic critic who mostly reviews films and television shows from his childhood and recent past, usually with comically exaggerated rage. The show often alternates the Critic's angry rants and humor with analysis of the episode's subject. Some of the films he reviewed (such as Exorcist II: The Heretic, The Garbage Pail Kids Movie, and Batman & Robin) are generally considered as the worst films ever made.

Walker briefly retired the series on August 14, 2012, to work on other projects, even writing the character out of existence in the Channel Awesome film To Boldly Flee. On January 22, 2013, Walker announced the show's return in a narrative video called "The Review Must Go On". The show subsequently returned with a more narrative and sketch-driven sixth season, beginning on February 5, 2013, with a review of The Odd Life of Timothy Green. Most episodes still retain the original clip using format.

'''Fingerboys''' are a species of monstrous soyjak that draw inspiration from modern horror games such as slenderman and other games popular with streamers. They have been sighted in Capitol Reef National Park.

They are very dangerous to the average Soyjak, but sometimes juvenile fingerboys are taken out of the nests for food. The hunting of their babies has led to an increase in fingerboy attacks. The only Soyjak that has been capable of defeating an adult fingerboy in unarmed combat is Swolesome Soyjak.

There is evidence that Fingerboys may have a weakness to Sproke. It is also possible that prolonged exposure to Sproke can cause harmful mutations in Fingerboys.

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

Melvin, Melvin, brother of the Joker! Melvin, Melvin, brother of the Joker! Melvin, Melvin, brother of the Joker! I’m cool! Hello! Hi, I am Melvin, the brother of the Joker! I'm sure a lot of you haven't heard of me...but, I am the brother of, yes the infamous Joker, y'know, 'why so serious' y’know, all that stuff...uh, actually I too have been working on my own catchphrase, um...Sploopity Sploosh! May not be as catchy, but uh I-I think it works. So, yeah! Alright uhh first of all I'd like to welcome all the newcomers to my blog, hello! Uh, hopefully we're going to talk a lot about evil! Lots of nasty evil evil! ...did I repeat myself- I guess it doesn't matter, umm, y'know cause evil does repeat itself, it's all about getting that massive....I dont know where I'm going with that. Anyway, okay, so uhh today's secret subject- or not secret it’s not- I mean this is all secret don’t tell anybody but, y’know today’s uh - big I should say, big subject is...Rayguns! Now, the th…. The thing about rayguns is that they are very very expensive as I found out! So- Mmmeeeelllvviiiiinnnn! ...So what you’re gonna wanna do, if you wanna get a raygun- Mmmmeellllvviiiiiinnnn!!!!! There-there’s uh, all sorts of rayguns that you can get! There’s um- Mmmmellllvvvviiiinnn what are you doing?! There’s uh- laser! Uh, there’s uh solar, There’s uh- Mmmeellllviiiiinnnn I want some hot chocolate. There’s uh, ones that fire bullets I guess that would just be a gun! There’s uh- Mmmelllllviiinnnnnn! Meeeellllllvviiiinnn!!! Little busy right now! Uh, there’s the ones that um, shoot raisins I haven’t seen that as much, uh, but they do exist I saw it on eBay! (Meeellvvviiiinnnnn!! Meeeelllllvvvviiiiin! Mmmeeeellllllvvviiiiiin! MelvIIIiiiiIIIIiiiIIIIiiiiIIIIiiiIIIIiiiiiIIIiiiinnn!) WHAT?! I’m thirsty, make me some hot chocolate! No, I’m busy! Busy doing what! I’m busy- that’s my um, uhh secretary, she is uh...very, very evil indeed! Mmmeellvviiin why haven’t you taken out the garbage yet! MOOOMM, PLEEEEASSEE DON’T ANNOY ME!!! Well then keep it down, Melvin! NO, I HAVE TO DO THIS MOM I- Keep it down, I’m trying to watch Glumbomerry Smetlock! I will try to keep it down, mother. Okay? Whaaat? I didn’t hear you. I SAID I WILL TRY TO KEEP IT DOWN- OWWWW YOU’RE HURTING MY EAARS MELVIN, YOU’RE HURTING MY EEAARS! So anyway! Such a failure! MOM!!! Why can’t you stop, I want my hot chocolate! I WILL NOT STOP, I NEED TO DO THIS MOM, I HAVE PEOPLE WATCHING! Oh wait, I had some hot chocolate the whole time! Where was I…? Isn’t that funny, Melvin? Oh, uh, r-r-r-rayguns! Yes, rayguns! Um, now, I have someone who is actually working on a raygun as we speak! ...And no it is not my mother…. I should probably address that! Uh, I do in fact live with my mother, I’m not ashamed to say that, uhh I just take a little longer to get going...uh, as opposed to other people. Uh, I see no shame in it...even though she constantly does. So, uh, basically what I would li- MEELLVIIN IT’S TOO HOT! [cut] Okay! I just slipped her about 50 vicodin so I think we’re good! Ahem, now one of the thi- MMEELLVIIN WHY IS THE ROOM SPINNING! My god, she’s like an ox! [cut] Okay, I just uh slipped a whole packet of nyquil into her milk, she’s gonna take a little nap now. Uh, so yeah, rayguns! Uh, I see a lot of villains using them, but um...let’s be honest, people. You don’t need them! Uh, what is it that a laser gun can do that a normal gun...can’t do! ...Destroy cities, sure, but if you get a gun that’s big enough...it could do that! I-I don’t know where you’d buy the bullets but I’m sure they’re out there! I’m sure they are out there - massive, massive bullets.... Okay maybe a raygun would be a very very good thing to get, I don’t know, uh...but, uh, I do not have the money for some, uh I’ve been debating whether or not how to uh, I’ve been uh, uh, thinking-thinking how to get uh, some-some-some bullets, uh, not bullets- god my mind I just can’t…. [Sighs] I’m sorry I just uh...I’ve just been under a lot of stress, you know, I uh...I still...haven’t gotten a job...y’know, uh…. What am I talking about, evil is my job! Yes, cause I am Melvin! The brother of the Joker! I-I- MEELLVIIIINNNN, MMELLVIIIIINNNNNN, MMMMMELLLLLVIIIIINNNNN!!!!! (She woke up, my god, how did she wake up? ) I’ll be in a minute, mom! So um, yeah, uh rayguns I don’t see the necessity of them! Such a failure! MOM!!! …So, uh, I do not see the necessity, uh, but I will somehow get one, I actually, I have a friend who was um, actually building me one, he uh- he works at circuit city I think I will just give him a call, right now! It’s ringing. Hey, B how you doin’! Melvin. The-th...Melvin Pothorn...the brother of the Joker? Yeah, yeah, that’s right haha I didn’t think you’d forget me! So, um, yeah how’s our uh, how’s our um, raygun doin’ there? Uh-huh. Oh what’d uh...I see. Well, does it still shoot lasers like we thought? Oh...Well, how large is it? 2 in- so that’s like, th-that could fit in my pocket. That’s not really a gun, that’s more of a toy. We-well what does it fire? It fires cashews. Well tha-that’s not gonna be very threatening to the...hero, is it? No it is not. I don’t care if the hero is allergic to nuts, it’s not gonna work! Okay, okay, calm down, calm down...I’m not talking to you I’m talking to me! N-no no I didn’t, I didn’t mean to yell at you, no-no I- no.... Do you really want me to sing it now, I...alright…. There’s a place, All over the world, Tonight. We will see each other, All throughout the night, Out of sight. Okay, so I can’t remember the words, alright? I-I-I don’t care! I-I y’know what? Y’know what? I don’t care, I don’t care, uh, I am evil and I’m going to destroy you, with or without your cashew gun. Goodbye! No- goodb-...yeah I’ll see you Tuesday. [Sigh] Kids! [cut] So yeah, um, I’m realizing this wasn’t a very good beginning, uh- uh blog, if you would, um, but uh my guess is that the next ones are gonna be better cause, uh, gonna do a lot more robbing, a lot more uh, uh stealing of things, and maybe, just maybe, I might pants somebody. Huh? Maybe a uh, certain somebody with pointed ears and wears, uh, all black? That’s right! The Human Ant, I’m gonna get him! Yeah…. Okay, Human Ant he’s not as big as someone like Batman or Superman but he is still a very impressive superhero! I mean, I-I don’t think it matters that he lives right next door to me, I think that’s still very very impressive- I know a superhero that can obliterate - no not obliterate that’s what I do - that can save people from me, uh, obliterating the world! Yes, yes, that is very impressive, I’m sure that’s a lot better than half the people you know! So, uh, just to reiterate: uh rayguns waste of time, uh, the human ant is my narch- arch, nemesis- god I can’t talk today, uhh, I think that’s it! Uh, this will be the first of many evilness that will be coming, so uh, again, this is Melvin, uh, brother of the Joker, signing off, and I- MMEELLLVIIIINNNNNN!!! MOM!!!!!! [cut] Come kiss me goodnight! Yeah, I’m comin’ mom! I’m comin’! Melvin, Melvin, brother of the Joker! Melvin, Melvin, brother of the Joker! Melvin, Melvin, brother of the Joker! I’m cool!

{{comic discussion}}
[[Category:Doug Walker]]
[[Category:Nostalgia Critic]]
[[Category:Channel Awesome]]
[[Category:Soyjaks]]
[[Category:Fingerboys]]
[[Category:Religion]]