explain xkcd - User contributions [en]

880: Headache

2022-05-11T16:23:29Z

Tianshuo: This April fools' comic is not interactive

{{comic
| number = 880
| date = April 1, 2011
| title = Headache
| image = headache.png
| titletext = I'm only willing to visit placid lakes, salt flats, and painting exhibits until the world's 3D technology improves.
}}

==Explanation==
This was the second [[:Category:April fools' comics|April fools' comic]] released by [[Randall]], but in principle the first real one to be released on April 1st, which in 2011 fell on a Friday, a normal release day for xkcd. The previous fools comic was literally [[404: Not Found|Not Found]]. After this comic Randall began releasing April Fools comic every year on April 1st disregarding the weekday of that date. The next was [[1037: Umwelt]] released on Sunday April 1st 2012, the first to use another day of the week than Monday, Wednesday or Friday.

Some people suffer from headaches, eyestrain, motion sickness and other problems when watching {{w|3D film|3D movies}}, playing 3D games, watching {{w|3D television}}, playing hand-held {{w|Nintendo 3DS}}, etc.

In this comic, Cueball is using the excuse that 3D gives him a headache to get out of going outside into the real world, where ''everything'' is in {{w|Three-dimensional space|3D}}. Instead he stays inside and looks at his 2D computer monitor. In the title text, he says he will only go to flat places (i.e. places where everything he could see would be 2D-like).

This comic was released on {{w|April Fools' Day}}. The April fools joke for 2011 made every comic on the site 3D, thus forcing people like Cueball to endure 3D even at their computer screens. An exception to this is [[848: 3D]], for which the third dimension is not visible. The 3D view is still available at [http://xk3d.xkcd.com/ xk3d.xkcd.com] for all comics prior to this one.

In his [https://vimeo.com/78912850 Øredev 2013 talk] [[Randall]] mentions that a few of his friends created this 3D view and told him just 1.5 hours before the scheduled comic for that day would go live. [[Randall]] quickly drew a 3D themed comic to match.

The title text suggests that Cueball is only comfortable seeing objects with visible flat surfaces like flat movie and TV screens (which the entertainment industry would not call "3D").

==Transcript==
:[Megan has a bike, and is wearing a helmet. Cueball is at a computer.]
:Megan: Wanna go for a bike ride?
:Cueball: Nah, I hate 3D stuff. It gives me a headache.
:When you think about it, this excuse can get you out of almost anything.

==Trivia==
*When clicking the 'next' or 'latest' buttons on the xk3d site, a blue {{w|Utah teapot}} appears, in random locations and sizes, instead of proceeding. Attempting to proceed beyond via manually pointing the URL elsewhere is not supported.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:April fools' comics]]

153: Cryptography

2013-09-02T08:26:29Z

Tianshuo: /* Explanation */

{{comic
| number = 153
| date = September 6, 2006
| title = Cryptography
| image = cryptography.png
| titletext = If you got a big keyspace, let me search it.
}}

==Explanation==
This comic, as the name implies, is relevant to the study of {{w|cryptography}}. At the podium, [[Cueball]] is describing a proposed crypto system (a computer program that turns a very large number, called the "{{w|key (cryptography)|key}}", and a message into an encrypted form that can only be read by using the same key), based on the model of a {{w|Feistel cipher}}. Part of any Feistel cipher is the "round function", which determines how the key is applied to the original message; this is applied multiple times with a variety of tricks and techniques to insure the process can eventually be reversed. One common component of round functions is the {{w|S-box}}, a simple table that converts input bytes into output bytes, preferably in a way that doesn't correspond to any mathematical rules.

Here, the S-box would be implemented by doing the following (with the computer operation actually shown in the diagrams indicated in parentheses):

#Take the bitstring down (roll right by 1)
#Flip it (take its binary NOT)
#Reverse it (run the bits in the opposite order)

This would be run on each round of the cipher to further scramble the message for the next round. As the caption implies, the steps are based on a line from the {{w|Missy Elliott}} song ''{{w|Work It (Missy Elliott song)|Work It}}'': "I put my thing down, flip it and reverse it."

The {{w|Key space (cryptography)|keyspace}} for a cryptographic algorithm is the number of possible keys the algorithm can possibly accept. For example, {{w|Advanced Encryption Standard|AES-256}} has a keyspace of 2256 (roughly 1.1579209e+77) possible keys, simply because the algorithm specifies that each key is 256 bits wide. The title text is referring to "searching a keyspace", which is to say, simply trying every key until you find one that works. (For reference, a computer would require roughly the energy of a billion billion supernovas to even count to 2256, let alone actually try each one.) The precise wording "If you got a big keyspace, let me search it" is, of course, another reference to the same song: "If you got a big **** let me search ya." (The **** in the song is apparently the sound of an elephant, but it is heavily implied from context to be "penis".)

Cueball is banned from multiple conferences for similar pranks([[541: TED Talk]]) and so is the author Randall Munroe (http://pycon.blogspot.com/2009/02/randall-munroe.html).

==Transcript==
:[Cueball at a podium.]
:Cueball: My cryptosystem is like any Feistel cipher, except in the S-Boxes we simply take the bitstring down, flip it, and reverse it.
:I've been barred from speaking at any major cryptography conferences ever since it became clear that all my algorithms were just thinly disguised Missy Elliot songs.

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

153: Cryptography

2013-09-02T08:22:15Z

Tianshuo: /* Explanation */

{{comic
| number = 153
| date = September 6, 2006
| title = Cryptography
| image = cryptography.png
| titletext = If you got a big keyspace, let me search it.
}}

==Explanation==
This comic, as the name implies, is relevant to the study of {{w|cryptography}}. At the podium, [[Cueball]] is describing a proposed crypto system (a computer program that turns a very large number, called the "{{w|key (cryptography)|key}}", and a message into an encrypted form that can only be read by using the same key), based on the model of a {{w|Feistel cipher}}. Part of any Feistel cipher is the "round function", which determines how the key is applied to the original message; this is applied multiple times with a variety of tricks and techniques to insure the process can eventually be reversed. One common component of round functions is the {{w|S-box}}, a simple table that converts input bytes into output bytes, preferably in a way that doesn't correspond to any mathematical rules.

Here, the S-box would be implemented by doing the following (with the computer operation actually shown in the diagrams indicated in parentheses):

#Take the bitstring down (roll right by 1)
#Flip it (take its binary NOT)
#Reverse it (run the bits in the opposite order)

This would be run on each round of the cipher to further scramble the message for the next round. As the caption implies, the steps are based on a line from the {{w|Missy Elliott}} song ''{{w|Work It (Missy Elliott song)|Work It}}'': "I put my thing down, flip it and reverse it."

The {{w|Key space (cryptography)|keyspace}} for a cryptographic algorithm is the number of possible keys the algorithm can possibly accept. For example, {{w|Advanced Encryption Standard|AES-256}} has a keyspace of 2256 (roughly 1.1579209e+77) possible keys, simply because the algorithm specifies that each key is 256 bits wide. The title text is referring to "searching a keyspace", which is to say, simply trying every key until you find one that works. (For reference, a computer would require roughly the energy of a billion billion supernovas to even count to 2256, let alone actually try each one.) The precise wording "If you got a big keyspace, let me search it" is, of course, another reference to the same song: "If you got a big **** let me search ya." (The **** in the song is apparently the sound of an elephant, but it is heavily implied from context to be "penis".)

Cueball is banned from multiple conferences for similar pranks([541: TED Talk]) and so is the author Randall Munroe (http://pycon.blogspot.com/2009/02/randall-munroe.html).

==Transcript==
:[Cueball at a podium.]
:Cueball: My cryptosystem is like any Feistel cipher, except in the S-Boxes we simply take the bitstring down, flip it, and reverse it.
:I've been barred from speaking at any major cryptography conferences ever since it became clear that all my algorithms were just thinly disguised Missy Elliot songs.

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

153: Cryptography

2013-09-02T08:19:44Z

Tianshuo: /* Explanation */

{{comic
| number = 153
| date = September 6, 2006
| title = Cryptography
| image = cryptography.png
| titletext = If you got a big keyspace, let me search it.
}}

==Explanation==
This comic, as the name implies, is relevant to the study of {{w|cryptography}}. At the podium, [[Cueball]] is describing a proposed crypto system (a computer program that turns a very large number, called the "{{w|key (cryptography)|key}}", and a message into an encrypted form that can only be read by using the same key), based on the model of a {{w|Feistel cipher}}. Part of any Feistel cipher is the "round function", which determines how the key is applied to the original message; this is applied multiple times with a variety of tricks and techniques to insure the process can eventually be reversed. One common component of round functions is the {{w|S-box}}, a simple table that converts input bytes into output bytes, preferably in a way that doesn't correspond to any mathematical rules.

Here, the S-box would be implemented by doing the following (with the computer operation actually shown in the diagrams indicated in parentheses):

#Take the bitstring down (roll right by 1)
#Flip it (take its binary NOT)
#Reverse it (run the bits in the opposite order)

This would be run on each round of the cipher to further scramble the message for the next round. As the caption implies, the steps are based on a line from the {{w|Missy Elliott}} song ''{{w|Work It (Missy Elliott song)|Work It}}'': "I put my thing down, flip it and reverse it."

The {{w|Key space (cryptography)|keyspace}} for a cryptographic algorithm is the number of possible keys the algorithm can possibly accept. For example, {{w|Advanced Encryption Standard|AES-256}} has a keyspace of 2256 (roughly 1.1579209e+77) possible keys, simply because the algorithm specifies that each key is 256 bits wide. The title text is referring to "searching a keyspace", which is to say, simply trying every key until you find one that works. (For reference, a computer would require roughly the energy of a billion billion supernovas to even count to 2256, let alone actually try each one.) The precise wording "If you got a big keyspace, let me search it" is, of course, another reference to the same song: "If you got a big **** let me search ya." (The **** in the song is apparently the sound of an elephant, but it is heavily implied from context to be "penis".)

Cueball is banned from multiple conferences for similar pranks([541: TED Talk]) and so is the author Randall Munroe (http://www.blog.pythonlibrary.org/2009/02/11/xkcd-artist-banned-from-pycon/).

==Transcript==
:[Cueball at a podium.]
:Cueball: My cryptosystem is like any Feistel cipher, except in the S-Boxes we simply take the bitstring down, flip it, and reverse it.
:I've been barred from speaking at any major cryptography conferences ever since it became clear that all my algorithms were just thinly disguised Missy Elliot songs.

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

1257: Monster

2013-08-29T01:55:01Z

Tianshuo:

{{comic
| number = 1257
| date = August 28, 2013
| title = Monster
| image = monster.png
| titletext = It was finally destroyed with a nuclear weapon carrying the destructive energy of the Hiroshima bomb.
}}

==Explanation==
{{incomplete}}

This comic is a parody on the opening scene of the thriller movie, The Pacific Rim. In the film, huge monsters called Kaiju entered the world through an inter-dimensional portal under the Pacific ocean and attacked coastal cities. It first attacked San Francisco, killing tens of thousands of people before its death after six days. In the comic, officials and police are evidently trying to describe the extraordinary qualities of the huge monster by comparing it with everyday objects instead of numbers, which is a concurring theme on xkcd ([[1047: Approximations]], [526: Converting to Metric]) and a blog article(http://blog.xkcd.com/2013/05/15/dictionary-of-numbers/) where Randall says "I don’t like large numbers without context."

This comic pokes fun at how common it is in the media to compare things of extraordinary qualities to a certain narrow set of well-known objects. The comic features people discussing a fictional monster which - apparently - can be only described by these overused comparisons. The caption and the title text take this joke further, especially with the tautology involved.

==Transcript==

:[People discussing anxiously over a table with a map. Megan has a notepad, Cueball and Ponytail are wearing police hats.]

:Megan: It's as long as a football field. Runs as fast as a cheetah.
:Cueball: Weighs as much as a blue whale.
:Blonde girl: Can we negotiate with it?
:Ponytail: No. It has the intelligence of a two-year-old child.

:Caption: By the time the Frequently-Made Comparisons Monster was finally defeated, it had eaten enough people to fill a stadium and devastated an area the size of Rhode Island.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Language]]

Talk:1257: Monster

2013-08-29T01:04:02Z

Tianshuo:

My first contribution, woo! I'm writing the transcript now. If there's an official one, please throw mine out and let me know :) [[User:Matega|Matega]] ([[User talk:Matega|talk]]) 06:13, 28 August 2013 (UTC)

I think it's done. Is it okay to refer to person 2 as Cueball and person 4 as Ponytail? As far as I know, Cueball is identified by not wearing anything... [[User:Matega|Matega]] ([[User talk:Matega|talk]]) 06:28, 28 August 2013 (UTC)
:Official transcripts tend to be days behind us. And yeah, we usually follow that naming convention for characters. '''[[User:Davidy22|{{Color|#707|David}}y²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 06:49, 28 August 2013 (UTC)
This comic should be based on Pacific Rim(http://www.imdb.com/title/tt1663662/) and the dictionary of numbers(http://blog.xkcd.com/2013/05/15/dictionary-of-numbers/) [[User:Tianshuo|Tianshuo]] ([[User talk:Tianshuo|talk]]) 08:07, 28 August 2013 (UTC)
: I've not seen Pacific Rim so I may be missing something obvious, but why? I don't see any obvious references to either. It's certainly in someways a continuation of the dictionary of numbers, but it looks at it from the other direction as a too often used cliche. [[Special:Contributions/131.123.61.160|131.123.61.160]] 10:51, 28 August 2013 (UTC)
:: I don't know why the original edit was deleted. This is definitely the opening scene of the movie Pacific Rim. [[User:Tianshuo|Tianshuo]] ([[User talk:Tianshuo|talk]]) 01:04, 29 August 2013 (UTC)

I like to relate this to [[1047: Approximations]] and [[526: Converting to Metric]] [[User:Theo|Theo]] ([[User talk:Theo|talk]]) 12:43, 28 August 2013 (UTC)
:Your links appear to be broken [[Special:Contributions/131.123.61.160|131.123.61.160]] 12:48, 28 August 2013 (UTC)

I added the basic tautology reference, but really wanted to add more, bracketted, maybe like: "(Usually overwhelmingly large amounts of conventional explosives, meteorite explosions or other non-nuclear energy-producers are likened directly as single-Hiroshima equivalent, although nuclear (or non-nuclear) blasts that are multiple-Hiroshimas in size maybe so scaled.)" But that looks too wordy. Feel free to adapt/adopt/correct. [[Special:Contributions/31.109.251.100|31.109.251.100]] 14:07, 28 August 2013 (UTC)

:Perhaps is could be noted that the Hiroshima bomb was one of the smallest nuclear bombs ever used. Probably enough to kill most monsters less than several football fields in length, but only about seven times the strength of the Halifax explosion. [[Special:Contributions/184.66.160.91|184.66.160.91]] 14:30, 28 August 2013 (UTC)

:How is it a tautology? Do all nuclear weapons "carry the destructive energy of the Hiroshima bomb"? [[Special:Contributions/70.29.69.4|70.29.69.4]] 19:33, 28 August 2013 (UTC)

1257: Monster

2013-08-28T08:14:28Z

Tianshuo: /* Explanation */

{{comic
| number = 1257
| date = August 28, 2013
| title = Monster
| image = monster.png
| titletext = It was finally destroyed with a nuclear weapon carrying the destructive energy of the Hiroshima bomb.
}}

==Explanation==
{{incomplete}}

This comic pokes fun at how common it is in the media to compare things of extraordinary qualities to a certain narrow set of well-known objects. The comic features people discussing on the opening scene of Pacific Rim(http://www.imdb.com/title/tt1663662/), where colossal monsters called Kaiju(which means Monster in Japanese) emerged from an interdimensional portal on the floor of the Pacific Ocean and attacked cities. The caption and the title text take this joke further.

==Transcript==
{{incomplete transcript}}

:[People discussing anxiously over a table with a map. Megan has a notepad, Cueball and Ponytail are wearing police hats.]

:Megan: It's as long as a football field. Runs as fast as a cheetah.
:Cueball: Weighs as much as a blue whale.
:Blonde girl: Can we negotiate with it?
:Ponytail: No. It has the intelligence of a two-year old child.

:Caption: By the time the Frequently-Made Comparisons Monster was finally defeated, it had eaten enough people to fill a stadium and devastated an area the size of Rhode Island.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Language]]

1257: Monster

2013-08-28T08:13:59Z

Tianshuo: /* Explanation */

{{comic
| number = 1257
| date = August 28, 2013
| title = Monster
| image = monster.png
| titletext = It was finally destroyed with a nuclear weapon carrying the destructive energy of the Hiroshima bomb.
}}

==Explanation==
{{incomplete}}

This comic pokes fun at how common it is in the media to compare things of extraordinary qualities to a certain narrow set of well-known objects. The comic features people discussing on the opening scene of Pacific Rim(http://www.imdb.com/title/tt1663662/), where colossal monsters called Kaiju emerged from an interdimensional portal on the floor of the Pacific Ocean and attacked cities. The caption and the title text take this joke further.

==Transcript==
{{incomplete transcript}}

:[People discussing anxiously over a table with a map. Megan has a notepad, Cueball and Ponytail are wearing police hats.]

:Megan: It's as long as a football field. Runs as fast as a cheetah.
:Cueball: Weighs as much as a blue whale.
:Blonde girl: Can we negotiate with it?
:Ponytail: No. It has the intelligence of a two-year old child.

:Caption: By the time the Frequently-Made Comparisons Monster was finally defeated, it had eaten enough people to fill a stadium and devastated an area the size of Rhode Island.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Language]]

User:Tianshuo

2013-08-28T08:09:30Z

Tianshuo: Created page with "Hello World, I am [http://tianshuohu.diandian.com Tianshuo Hu]"

Hello World, I am [http://tianshuohu.diandian.com Tianshuo Hu]

Talk:1257: Monster

2013-08-28T08:07:50Z

Tianshuo: