explain xkcd - User contributions [en]

2293: RIP John Conway

2024-07-24T14:03:22Z

108.162.221.62: /* Table of generations */

{{comic
| number = 2293
| date = April 13, 2020
| title = RIP John Conway
| image = rip_john_conway.gif
| titletext = 1937-2020
}}

==Explanation==
{{w|John Horton Conway|John Conway}}, an English mathematician, passed away of [[:Category:COVID-19|COVID-19]] on April 11, 2020. ([http://conwaylife.com/wiki/Conway Alternative link]) Two days later, [[Randall]] created this [[:Category:Tribute|memorial comic]]. It is the 6th memorial comic, but it is the first released in almost 5 years, since [[1560: Bubblegum]].

One of Conway's most famous creations was the {{w|cellular automaton}} known as {{w|Conway's Game of Life}}. A cellular automaton is a machine composed of cells, each of which can be in a different state. Every generation, each cell in the automaton may transition to a new state depending on a set of rules. (Conway's work in mathematics was vast and various, but he is perhaps best known in the field for discovering the {{w|surreal numbers}}, which inspired [[Donald Knuth]] to write a novel which may have been referenced back in [[505: A Bunch of Rocks]].)

Conway's Game of Life was first popularized to the general public in the form of a game, Life Genesis, bundled into some distributions of Windows 3.1, an operating system from the early-90s that Randall most likely used in his preteen years.

Conway's Game of Life is a 2-state automaton (i.e., every cell can be "alive" or "dead") that is implemented on a two-dimensional grid of cells using the {{w|Moore neighborhood}} - this means that each cell can only be influenced by the eight cells directly surrounding it, both orthogonally and diagonally. The transition rules that Conway used are as follows:

* If an "alive" cell has no live neighbors, or only one live neighbor, it becomes "dead". (This simulates death by isolation).
* If an "alive" cell has four or more live neighbors, it becomes "dead". (This simulates death by overcrowding).
* If a "dead" cell has exactly three live neighbors, it becomes "alive". (This simulates birth).

Despite the simplicity of these three rules, Conway showed that patterns of amazing complexity can nonetheless develop out of simple cell arrangements. Some patterns do not evolve at all ("still lifes"), some enter a cyclic, repeating state ("oscillators"), and some reproduce their own pattern displaced by an offset, resulting in patterns that can move across the grid under their own power ("gliders" and "spaceships"). This last category is of particular interest, as it allows the Game of Life to transmit information from one location to another, allowing for rich, dynamic behavior and even for the creation of computational machines within the automaton itself.

This comic begins with the shape of a stick figure as the starting cell configuration of the Game of Life. The black cells are "alive" and the white cells are "dead". This configuration then evolves via Conway's rules, disintegrating into nothingness except for a five-cell pattern known as a "glider", which ascends up and to the right. This visually suggests an eternal "soul" breaking away as the corporeal body disintegrates. The glider is perhaps the most iconic pattern of the Game of Life, and is often used symbolically to represent the phenomenon of emergence.

Here the topology of the grid on which the cells evolve is not known, the cellular automaton can be run on many topologies, for example you can choose to make cells reappear from the opposite side once they reach an edge (similarly to the behaviour of the well known Pacman). Here once the glider reaches the top right, we know for sure that the actual grid is bigger (since the glider leaves the frame while continuing its pattern), and we are only seeing part of the full grid.

The initial state presented in the comic does actually evolve in that manner, as can be verified by entering the pattern into a cellular automaton simulator such as [http://golly.sourceforge.net/ Golly] or web services such as [https://bitstorm.org/gameoflife/ this one] or [http://catagolue.hatsya.com/object/xkcd_48jsj8gzwe9e/b3s23 that one]. It seems that no one else have created this pattern before. At least, despite discussion in the comments, no one has found anything to show that this is not Randall's own discovery of this pattern.

The title text simply states Conway's birth and death year: 1937-2020.

Conway's Game of Life was previously mentioned in [[696: Strip Games]]. Cellular automata was also referenced in [[505: A Bunch of Rocks]].

This comic is the 18th comic in a row (not counting the [[2288: Collector's Edition|April Fools' comic]]) in a [[:Category:COVID-19|series of comics]] related to the {{w|COVID-19 pandemic}}. Although this comic is, of course, mainly a tribute to John Conway, the fact that he died of COVID-19 in the middle of this long series of coronavirus-related comics by Randall is relevant.

==Table of generations==
{| class="wikitable"
!Generation
!Notes
|-
|[[File:Generation 0.jpg|thumb]]||Starting state (or "zeroth generation").
|-
|[[File:Generation 1.jpg|thumb]]||First generation. Note that this image is not aligned with the previous one: the position of all cells has shifted downward by one cell. All further generations are aligned the same as this one.
|-
|[[File:Generation 2.jpg|thumb]]||Second generation.
|-
|[[File:Generation 3.jpg|thumb]]||Third generation.
|-
|[[File:Generation 4.jpg|thumb]]||Fourth generation.
|-
|[[File:Generation 5.jpg|thumb]]||Fifth generation.
|-
|[[File:Generation 6.jpg|thumb]]||Sixth generation. The first appearance of the {{w|Glider (Conway's Life)|glider}}, a well-known formation in Conway's Game of Life.
|-
|[[File:Generation 7.jpg|thumb]]||Seventh generation.
|-
|[[File:Generation 8.jpg|thumb]]||Eighth generation.
|-
|[[File:Generation 9.jpg|thumb]]||Ninth generation.
|-
|[[File:Generation 10.jpg|thumb]]||Tenth generation. The remains of the chaos down below will take two more generations to disappear completely.
|}

==Transcript==
:[A pixelated image of a stick figure using 21 pixels, could be a pixel Cueball, which waves with one hand up while holding the other hand down. The head consist of 7 pixels, the top row of three having two pixels beneath the two outer pixels, thus having two empty pixels beneath the central pixel. The neck and torso is a typical cross made from six pixels. The two legs are two pixels each shifted left and right of the cross. The arm to the left that waves is two pixels one down and the next back up to the level of the cross central beam. The arm to the right has the first pixel similarly but the second pixel continues one further step down. After less than one second it turns out that the image is animated, with the pixels changing according to the rules of Conway's Game of Life. The figure splits into three groups, two of which dissipates in a similar way at the bottom of the panel. The other becomes a 'glider' and moves off to the top-right corner of the image and out of the frame. The animation then repeats.]

==Trivia==

* "XKCD RIP John Conway" has been cited on [http://conwaylife.com/wiki/Pure_glider_generator LifeWiki]
* "XKCD RIP John Conway" is now available on [http://catagolue.hatsya.com/object/xkcd_48jsj8gzwe9e/b3s23 Catagolue] 

==Issues with some clients==

Some clients of the site crashed on this xkcd, most notably the Samsung Smart TV client.

{{comic discussion}}

[[Category:Comics with animation]]
[[Category:Comics featuring real people]]
[[Category:Tribute]]
[[Category:COVID-19]]
[[Category:Dynamic comics]]

Talk:1603: Flashlights

2015-11-14T06:03:24Z

108.162.221.62:

Is that it? I swear there must be more to the joke than this explanation implies. It just describes what's going on in the comic. [[User:Enchantedsleeper|Enchantedsleeper]] ([[User talk:Enchantedsleeper|talk]]) 10:29, 13 November 2015 (UTC)

-- Sometimes a cigar is just a cigar. [[User:Pete|Pete]] ([[User talk:Pete|talk]]) 11:19, 13 November 2015 (UTC)

---- but sometimes there is no spoon [[Special:Contributions/108.162.221.62|108.162.221.62]] 06:03, 14 November 2015 (UTC)

"A typo", uh? Sure, sure, of course it was only a typo, Randall ;) [[Special:Contributions/108.162.221.57|108.162.221.57]] 10:38, 13 November 2015 (UTC)
:I also think the type was that he searched on flashlight instead and found the flashlight enthusiast page from that ;-) --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 14:58, 13 November 2015 (UTC)

I think it's unfair to assume lack of detail in the explanation, the fact that research was obviously done on the meaning of fleshlight an it's association to the comic, is more than I would have original got from the comic by itself. However if you perceive additional meaning please share, the thing I love about 'This' website is for the ability for others to add their interpretations. --[[User:Igwarrender|Igwarrender]] ([[User talk:Igwarrender|talk]]) 10:52, 13 November 2015 (UTC)

Quote:
<blockquote>When Cueball refers to classic Flashlights(torches) as dim and finnicky, this gives reason to assume that the flashlight he is holding is going to be ridiculously overengineered.</blockquote>
I disagree. In the generation of Randall (and me), the flashlights most of us had as kids really did suck and were dim and finnicky. That's not an exaggeration which, as is implied in the explanation, is used to prepare the joke. It's more of an explanation on why he is interested in modern flashlights in the first place. --[[Special:Contributions/162.158.91.225|162.158.91.225]] 10:58, 13 November 2015 (UTC)
: AND they almost always had at least half flat batteries. [[Special:Contributions/198.41.239.32|198.41.239.32]] 11:41, 13 November 2015 (UTC)

It's funny how "the explanation" has a need to point out that there were no prior knowledge about fleshlights. (according to Wikipedia) [[Special:Contributions/162.158.180.197|162.158.180.197]] 12:44, 13 November 2015 (UTC)

I never leave for work without my trusty '''Lumapower EDC-LM31''' with its '''Cree XML(U2) LED''' and its '''3.7 volt size 14500 Lithium Ion cell.''' But I'm not a flashlight geek! Besides, 420 lumens is no where near enough power to set trees on fire. (Personally, I think this comic is an example of Rule 34. Randall was originally thinking about Fleshlights, typo'd into flashlights, and discovered a sort of geeky torch porn sort of thing out there. Also, the flashlight I describe is real, but has nothing on the stuff you'll see in Candlepower Forums.) [[User:Co149|Co149]] ([[User talk:Co149|talk]]) 12:52, 13 November 2015 (UTC)
:The 100,000 lumen lamps (X-LED MRK72 or is that MKR72?) have to be water-cooled! That's plenty hot enough for me.[[Special:Contributions/162.158.34.147|162.158.34.147]] 14:07, 13 November 2015 (UTC)
::There are videos of flashlights that set things on fire, without lensens etc. One of them is [https://www.youtube.com/watch?v=DhdKnMlJ4H4 this] video of an ''Magic Scorpion'' flashlight, a halogen variant. But I've also seen video's of (custom-built) LED flashlight that set things to smolder. [[Special:Contributions/141.101.104.111|141.101.104.111]] 14:56, 13 November 2015 (UTC)
: It's not lumen that sets things on fire, it's lux. All you need is a good focus. --[[Special:Contributions/198.41.235.101|198.41.235.101]] 17:11, 13 November 2015 (UTC)
: Also note [https://www.youtube.com/watch?v=NkkU0UO3sek this] flashlight, which is just a bunch of ultra-bright LEDs crammed into a case that resembles an oversized flashlight and on full power drains its battery in about 15 minutes...and lights up a city street like it's day. --NXTangl [[Special:Contributions/108.162.216.42|108.162.216.42]] 21:33, 13 November 2015 (UTC)

It feels to me that "their highest-end models are ALSO capable of setting trees on fire." is some advertisement where the tree is a metaphore for one's organ. as such it is clear that "They're impossible to use without severe burns". which makes it really twisted that "some [people] swear it's worth it" {{unsigned ip|108.162.228.167}}

I think the burning trees joke comes from this [[http://www.wickedlasers.com/torch "...even fry and egg"]] thing. --[[User:Arturojain|Arturo Jain]] ([[User talk:Arturojain|talk]]) 14:26, 13 November 2015 (UTC)

Should the explanation contain something about the prevalence of internet forums dedicated to enthusiasts of various activities or hobbies? [[User:Smperron|Smperron]] ([[User talk:Smperron|talk]]) 17:33, 13 November 2015 (UTC)

Currently no (albeit indirect) link to https://what-if.xkcd.com/13/ or others like 119? Ok, so only going to be an incidental link, but... [[Special:Contributions/141.101.106.161|141.101.106.161]] 17:37, 13 November 2015 (UTC)

it is missimg reference to another comic where randall makes a joke about flashlight and fleshlight. The comic had a star wars setting with death vader and luke skywalker. https://xkcd.com/1397/ --anonymous [[Special:Contributions/162.158.153.41|162.158.153.41]] 15:08, 13 November 2015 (UTC)

"Let's" appears to be missing an apostrophe. [[Special:Contributions/173.245.54.21|173.245.54.21]] 20:23, 13 November 2015 (UTC)

Now, see, this is why we Brits call them 'torches'. Less risky with finger trouble. (Hint - don't google 'finger trouble') [[User:Jdluk|Jdluk]] ([[User talk:Jdluk|talk]]) 21:52, 13 November 2015 (UTC)

could it be referencing http://www.wickedlasers.com/torch ?

[[Special:Contributions/173.245.54.38|173.245.54.38]] 17:54, 13 November 2015 (UTC)an internet flashlight enthusiast

Why are there personal opinions like "maybe they're trying to trick you!" in the main body? Weird. [[Special:Contributions/162.158.142.140|162.158.142.140]] 02:26, 14 November 2015 (UTC)

"Of course, a flashlight that cannot safely be pointed at things is fairly useless for the traditional purpose of a flashlight". Really now? A flashlight that set targets on fire is pretty useful - you only need to flash something once, and it'll stay illuminated without having to keep the flashlight on![[Special:Contributions/108.162.242.134|108.162.242.134]] 05:26, 14 November 2015 (UTC){{unsigned ip|192.0.189.206|12:34, 5 June 2012 (UTC)}}

1603: Flashlights

2015-11-14T06:01:20Z

108.162.221.62: /* Explanation */ I have my reasons

{{comic
| number = 1603
| date = November 13, 2015
| title = Flashlights
| image = flashlights.png
| titletext = Due to a typo, I initially found a forum for serious Fleshlight enthusiasts, and it turns out their highest-end models are ALSO capable of setting trees on fire. They're impossible to use without severe burns, but some of them swear it's worth it.
}}

==Explanation==
In this comic, [[Cueball]] has acquired or built a new high powered flashlight, which he wants to demonstrate to [[Megan]]. When Cueball refers to classic {{w|flashlights}} (battery torches) as dim and finnicky, this gives reason to assume that the flashlight he is holding is going to be ridiculously overengineered.

Indeed, when he switches it on outside the house, the intense light beam completely drowns out the scene. Only the reflected light from the forest lights up the part of Cueball and Megan's faces that are turned towards it.

Cueball comments that the flashlight lights up the entire forest, but Megan observes that it is the trees that are on fire, indicating that Cueball's flashlight is so overpowered that the energy of its beam is sufficient to cause the organic matter of trees to combust.

Of course, a flashlight that cannot safely be pointed at things is fairly useless for the traditional purpose of a flashlight, which would be to find things in the dark by directing light over them. This mundane and practical reasoning does not seem to matter to Cueball of course, who appears only interested in the intensity and brightness the device is capable of achieving.

Cueball might allude to a number of technical improvements, notably xenon-based incandescent bulbs, multiple-LED assemblies, Lithium batteries (usually used for photography flashes) or rechargeable batteries. A number of companies market "tactical" flashlights that are supposedly powerful enough to incapacitate an opponent, using terms such as "scorching" to advertise their products.

The title text refers to {{w|Fleshlight}} a brand of male masturbation toys modeled after various female or male orifices. Cueball (or [[Randall]]) claims that he only arrived on a forum for Fleshlight enthusiasts due to a typo. Apart from the "e" vs. "a" in Fleshlight, they are also fashioned to look like oversized flashlights. On that forum here he found out that the highest-end models of their product lines was also capable of setting trees on fire. This would probably happen due to violent vibrations inside the orifice, or excessively powerful internal heating. If you use one of these you should expect to obtain severe burns in a very unpleasant area.{{Citation needed}} But some of the enthusiasts swear that it is still worth it, in the same manner that Cueball only cares about the intensity of the flashlight, regardless of the consequences. Maybe they are just trying to trick you into doing something stupid! Or maybe they're just into that kind of thing.

==Transcript==
:[Four panels are laid out horizontally.]

:[Panel 1: Cueball carries a flashlight walking towards Megan who is sitting on a couch]
:Cueball: Remember how flashlights sucked when we were kids? Always dim and finnicky?
:Megan: I guess?

:[Panel 2: Cueball and Megan walking to the left]
:Cueball: Well, I discovered there are now internet flashlight enthusiasts.
:Cueball: And the technology has... improved.
:Megan: OK, Let's see.

:[Panel 3: It is dark outside where Cueball turns on the flashlight. The beam is very bright and very visible even seen from the side. Backscattered light reflects off Cueball and Megan's faces, turning them into bright white beings in the dark. The facade of the house and the stairs are also visible in the same manner, with deep dark shadows where anything is in the shadow. Megan averts her face from the light holds up a hand to cover her eyes. When the flashlight turns on it even makes a sound, written in white above the beam:]
:Flashlight: '''''FWOOSH'''''

:[Panel 4: Cueball and Megan look at what the beam falls on (outside the frame). Megan has taken her hand down. Both their faces are only lit up like a crescent moon. Cueball is holding the flashlight with both hands as if it is pushing back on him. The text is written in white on the dark sky above them.]
:Cueball: See how it lights up the whole forest?
:Megan: ... The trees are on fire.
:Cueball: Real bright, though.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics with inverted brightness]]
[[Category:Sex]]

1054: The bacon

2015-10-22T03:48:21Z

108.162.221.62: /* Explanation */

{{comic
| number = 1054
| date = May 11, 2012
| title = The Bacon
| image = thebacon.png
| titletext = Normally pronounced 'THEH-buh-kon', I assume.
}}

==Explanation==
This comic plays off the American {{w|colloquialism}} "bring home the bacon", which generally means to work hard and bring money home to your family to put food on the table.

[[White Hat]] seems to actually be saying "{{w|thebacon}}", and is thus calm because his wife gives him drugs. {{w|Vicodin}} is a very common painkiller, that can become a drug of abuse.

According to {{w|thebacon|Wikipedia}}, [[Randall]] seems to be mistaken in (gasp{{Citation needed}}) ''three'' places:
*The proper name is ''dihydrocodein<u>on</u>e'' enol acetate.
*It is a {{w|semisynthetic|''<u>semi</u>synthetic''}} {{w|opioid}}.
*The pronunciation is /ˈθiːbəkɒn/ (''thee''-buh-kon).

==Transcript==
:White Hat: I'm out of work, but I'm not stressed about it because my wife is a pharmacist and she brings home thebacon.
:Caption: Only later did I learn that "thebacon" is the common name for Dihydrocodeine Enol Acetate, a synthetic opioid similar to Vicodin.

{{comic discussion}}
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Language]]

1032: Networking

2014-06-06T03:31:58Z

108.162.221.62: /* Explanation */ We haven't quite proven that such things are not common behaviour. A citation is in order if we can prove such a thing.

{{comic
| number = 1032
| date = March 21, 2012
| title = Networking
| image = networking.png
| titletext = Our company is agile and lean with a focus on the long tail. Ok, our company is actually a polecat I found in my backyard.
}}

==Explanation==
Obviously, [[Beret Guy]]'s [[business plan]] worked.

Networking, in business, is the act of expanding your group of contacts in order to help your career down the line. Here, in this comic, [[Beret Guy]] meets Chief Technology Officer (CTO, an executive level position overseeing development of new technologies) Connr Clark (perhaps a typo for "Connor" or perhaps a reference to common "Web 2.0" names like the businesses {{w|Flickr}}, {{w|Tumblr}}, etc.) and Beret Guy is as strange as he usually is. This time he has a business card, which usually contains contact information, but only says "This is my business card". He calls his briefcase, or suitcase, a "handlebox", which is full of a quarter of a million dollars in cash. Then Beret Guy proceeds to eat Connr's business card. All of these things are not common behavior (citation needed).

"Networking" is often an over-hyped, empty affair. There are zillions of networking meetings of every description going on every day everywhere, and mostly people trade cards and continue to not make money. So that's the joke – Beret Guy does the networking schtick, badly, and yet is somehow making huge amounts of money at it.

The comic is also likely a joke on the idea that many people are excited about becoming a "business professional" who carries a briefcase, hands out business cards, and makes tons of money, without having an adequate plan for how to make those things happen, or possibly even knowing what their actual job would be. Beret Guy never says what he does, simply introducing himself as a "business professional," and explains his piles of cash with "I am a business grown-up who makes business profits!" In this world —and in people's dreams— when you "grow up" and start a business, money magically appears. Obviously, that's not how it works.

The title text is a pun on three common business buzzwords: agile, lean and long-tail. An agile business is one that can change course quickly based on customer demands and the business environment. A lean business is an efficient one that can provide results for customers without any wasted time, energy or money. Long-tail describes the retailing strategy of selling a large number of unique items with relatively small quantities sold of each – usually in addition to selling fewer popular items in large quantities. The best example I can think of for long-tail is Netflix, because they have (almost) every movie imaginable, including rare ones that only a few people would be interested in. Well, they ''pretend'' to; in reality, your movie may be marked Saved for years until they actually manage to get a copy, if they ever do.

And of course, the pun here is one animal that is agile and lean with a long tail is a {{w|polecat}}.

Furthermore, although "agile" and "lean" do mean a quick, nimble, and efficient business, they also refer to specific practices, as in {{w|Agile Software Development}}, {{w|Lean Manufacturing}} and {{w|Lean Six Sigma}}. Many people think these terms have devolved to overused jargon. While Agile is supposed to be a highly structured method to get programmers to produce more working code quickly, when someone from the marketing department says "''Agile''" it often means "''We don't know what we're supposed to be producing, so we'll just chuck some stuff together, and keep those bits that the customer says he likes. We'll then do it all over again until we've got something that he'll pay for.''" "''Lean''" is supposed to mean that a business keeps its costs as low as possible, employing one person to do marketing and PR, not really having a Human Resources department, etc. But, in practice it often becomes "''Keep as little stock as possible so that we don't have a lot of money tied up in it, and don't need a big warehouse; make stuff just before it is supposed to ship so that we don't have to store it either; make frequent prayers and virgin sacrifices to whatever gods we can find to ensure that nothing slips up anywhere along the line that our lawyers can't get us out of.''"

==Transcript==
:[A man approaches Beret Guy at a party and they extend arms to shake hands. Beret Guy is holding a metal briefcase. There is a waitress in the background, carrying a tray with a wine glass on it.]
:Man: I'm Connr Clark, CTO at Eusocial Media Ventures.
:Beret Guy: I'm a business professional! Earlier I photocopied a burrito!

:[The man hands Beret Guy a business card. Beret Guy takes it and hands the man another business card. Beret Guy has put his suitcase on the floor.]
:Man: You should check us out! Here's my card.
:Beret Guy: Here's mine! Networking!

:[The man takes a closer look at the card, and Beret Guy holds up his case.]
:Man: ...this just says "This is my business card!"
:Beret Guy: Do you like it? I have more in my handlebox.

:[Beret Guy puts his case on a table and opens it to reveal it is full of cash. The man looks on in shock.]
:Man: Uh, that's ok, I think I'll—
:Beret Guy: Here, have ten of them!
:Man: —holy shit that thing is full of ''cash!''

:[The man raises his arms in excitement. Beret Guy turns to face him and chews on the man's business card.]
:Man: Where did you ''get'' that?
:Beret Guy: I am a business grown-up who makes business profits!
:Man: That's like a quarter of a million dollars!
:Beret Guy: Yay! Business is fun! Do you have more of your cards? They're ''delicious!''

{{comic discussion}}
[[Category:Comics featuring Beret Guy]]
[[Category:Comics with color]]

Talk:674: Natural Parenting

2014-06-05T21:18:09Z

108.162.221.62:

The song "Doing What Comes Naturally" from Irving Berlin's ''Annie Get Your Gun'' also explores this meaning: "Grandpa Bill is on the hill / with someone he just married. / There he is at ninety-three / doing what comes naturally." [[Special:Contributions/108.162.216.38|108.162.216.38]] 19:41, 22 January 2014 (UTC)

The title text includes the phrase "the mother of all sampling biases". This is a riff on the phrase "the mother of all battles", which was originally used by Saddam Hussein, the late president of Iraq, to refer to the first Gulf War (1990-1991, when Iraq invaded Kuwait and was later beaten back to its borders by a coalition of forces from other countries). Since then, the phrase "the mother of all X" for various X has become something of a meme. Here, it's more ironic than usual, because (a) parenting can sometimes be viewed as something of a battle and (b) as the explanation already suggests, the comic is literally about being a parent.[[Special:Contributions/173.245.54.61|173.245.54.61]] 04:26, 5 June 2014 (UTC)

"The Mother of all sampling biases" also refers to the fact that he's talking about his mother, and his mother's mother, and his mother's mother's mother, all the way back to Eve.[[Special:Contributions/108.162.221.62|108.162.221.62]] 21:17, 5 June 2014 (UTC)

Talk:674: Natural Parenting

2014-06-05T21:17:39Z

108.162.221.62:

The song "Doing What Comes Naturally" from Irving Berlin's ''Annie Get Your Gun'' also explores this meaning: "Grandpa Bill is on the hill / with someone he just married. / There he is at ninety-three / doing what comes naturally." [[Special:Contributions/108.162.216.38|108.162.216.38]] 19:41, 22 January 2014 (UTC)

The title text includes the phrase "the mother of all sampling biases". This is a riff on the phrase "the mother of all battles", which was originally used by Saddam Hussein, the late president of Iraq, to refer to the first Gulf War (1990-1991, when Iraq invaded Kuwait and was later beaten back to its borders by a coalition of forces from other countries). Since then, the phrase "the mother of all X" for various X has become something of a meme. Here, it's more ironic than usual, because (a) parenting can sometimes be viewed as something of a battle and (b) as the explanation already suggests, the comic is literally about being a parent.[[Special:Contributions/173.245.54.61|173.245.54.61]] 04:26, 5 June 2014 (UTC)
"The Mother of all sampling biases" also refers to the fact that he's talking about his mother, and his mother's mother, and his mother's mother's mother, all the way back to Eve.[[Special:Contributions/108.162.221.62|108.162.221.62]] 21:17, 5 June 2014 (UTC)

1286: Encryptic

2014-05-28T00:15:24Z

108.162.221.62: /* Passwords */ Sugarland is not a city! I live in Sugar Land. It's the most mildly infuriating thing I've ever known

{{comic
| number = 1286
| date = November 4, 2013
| title = Encryptic
| image = encryptic.png
| titletext = It was bound to happen eventually. This data theft will enable almost limitless [xkcd.com/792]-style password reuse attacks in the coming weeks. There's only one group that comes out of this looking smart: Everyone who pirated Photoshop.
}}

==Explanation==
Web sites and other computers that authenticate users via passwords need to be able to know if the user typed in the right password. But storing the password itself on the computer has been known to be unnecessarily risky since the publication of [http://www.neurosecurity.com/articles/security/passwd.pdf Password Security: A Case History] in 1978. In that paper, Robert Morris and Ken Thompson demonstrated the practice of using a slow, cryptographically-secure one-way {{w|hash function}}, so that even if the password file is stolen, it will be very hard to figure out what the passwords are, so long as the passwords themselves are suitably complex. They also pioneered the use of {{w|Salt (cryptography)|a "salt"}} which makes each password hash completely different even if two users use the same password. See [http://security.blogoverflow.com/2011/07/a-tour-of-password-questions-and-answers/ A tour of password questions and answers] for background on salts and suitably slow hash functions.

Adobe, however, ignored these well-known principles, and instead stored over a hundred million passwords in a reversibly encrypted way, using a terrible choice of encryption methods which exposes a great deal of information about the passwords, and does not involve a salt. This password database was recently obtained by someone and released on the Internet.

In particular, Adobe used {{w|Triple DES}}, an older encryption algorithm which can still be relatively secure when properly used but they used it improperly. It works on 64-bit (8 character) blocks. Assuming that the passwords are stored in plain ASCII, this means that a sequence of 8 characters in a password which starts on a character position which is a multiple of eight is always encrypted to the same result. Therefore two passwords starting with "12345678" would start with the same block after being encrypted. Furthermore, this means that you can actually get a very good idea of the length of the password since anything with only one block is a password with length between 1 and 8 characters, and having two blocks implies it has between 9 and 16 characters, etc.

Adobe also stored hints users created for their passwords. That means that an attacker knows not only if the same 8 characters are used for multiple passwords but also has some hints for guessing them. That means that common password portions should be easy to recover and that any user may be "compromised" by someone else using a part of the same password and providing a good hint. As an example, a password having three hints "Big Apple", "Twin Towers" and "If you can make it there" is probably "New York" (or a simple variation on that). The weakness here is that no decryption and therefore no hard cracking has to take place, you just group the passwords by their encrypted blocks and try to solve them like a crossword puzzle. These weaknesses have already been used to presumably identify a password used by {{w|Edward Snowden}}, as discussed at [http://7habitsofhighlyeffectivehackers.blogspot.com/2013/11/can-someone-be-targeted-using-adobe.html 7 Habits of Highly Effective Hackers: Can someone be targeted using the Adobe breach?].

The examples are not taken from the actual leaked file, since that [http://arstechnica.com/security/2013/11/how-an-epic-blunder-by-adobe-could-strengthen-hand-of-password-crackers/ uses a different format], and the examples are evidently cleverly crafted to make a nice crossword-like puzzle, which can be solved as shown in the Passwords section below.

As mentioned on http://filosottile.github.io/analyzing-the-adobe-leaked-passwords/ the data in the comic isn't real and contains a hidden message.
If the "user password" hashes are Base64 encoded, they read:
<pre>ThiswasnotagooduseofyourtimeButthenagainitwasprobablynotagooduseofmytimeeith
erAndyethereweareXOXOXOLetsLiveHereInThisTinySecretEncodedTextWorldForever==</pre>

E.g., with the initial unique hash blocks: <tt>python -c "print '4e18acc1ab27a2d6a0a2876eb1ea1fca'.decode('hex_codec').encode('base64')"</tt>

The last letter "r" is not fully encoded in the data shown, but any letter from "g" to "v" produces the same binary data.

The title text makes a reference to a previous comic: [[792|Black Hat's trouble with what to do with stolen passwords]]. It also states that users of pirated Photoshop are the winners here. This is because in order to make Photoshop pirate-able, it was modified (cracked) by removing the requirement for registration so their passwords were not sent to Adobe and therefore are not present in the leaked file.

The title itself is a reference to [http://en.wikipedia.org/wiki/Cryptic_crossword cryptic crosswords]

==Passwords==
Note that characters in the passwords could be upper or lower case, and they may involve common substitutions like "0" (number zero) for "O" (letter O); therefore, the clues cannot guarantee that the answer shown here is precisely correct. Nevertheless, we have plenty of information for a brute force attack.

{|class="wikitable"
! Input
! Hint
! Password
! Explanation
|-
|<tt>4e18acc1ab27a2d6</tt>
|weather vane sword
|<tt>[http://redwall.wikia.com/wiki/Matthias matthias]</tt>
|In ''{{w|Redwall}}'', several characters are associated with a sword hung from a weather vane, but only Matthias shares the name of an apostle (6 lines down).
|-
|<tt>4e18acc1ab27a2d6</tt>
|
|<tt>matthias</tt>
|Although no hint was used, we know this password too, since it matches the previous one.
|-
|<tt>4e18acc1ab27a2d6 a0a2876eb1ea1fca</tt>
|name1
|<tt>matthias1</tt>
|Even without knowing the user's name, we already know how this starts, so the clue gives us a pretty good idea how it finishes (and another block useful 2 lines down)
|-
|<tt>8babb6299e06eb6d</tt>
|duh
|<tt>password</tt>
|Unfortunately, this is all too common, and the user practically told us that it's an easy one.
|-
|<tt>8babb6299e06eb6d a0a2876eb1ea1fca</tt>
|
|<tt>password1</tt>
|Although no hint was used, we know this by combining the previous two.
|-
|<tt>8babb6299e06eb6d 85e9da81a8a78adc</tt>
|57
|<tt>password57</tt>
|Since we know how this begins, this is a good guess.
|-
|<tt>4e18acc1ab27a2d6</tt>
|favorite of {{w|Apostle (Christian)|12 apostles}}
|<tt>{{w|Saint Matthias|matthias}}</tt>
|The hint suggests only 12 possibilities. Variant spellings, variant lists, and a replacement for Judas add to that number. But we already know which one by combining with the clue 6 lines up. (Surprise: it's the replacement!)
|-
|<tt>1ab29ae86da6e5ca 7a2d6a0a2876eb1e</tt>
|with your own hand you have done all this
|<tt>Judith1510</tt>
|This is a quotation from [http://www.biblestudytools.com/nrsa/judith/15-10.html Judith 15:10] in the Bible.
|-
|<tt>a1f9b2b6299e7a2b eadec1e6ab797397</tt>
|sexy earlobes
|<tt>{{w|Charlie Sheen|Charlie Sheen}}</tt>
|This refers to an episode of ''{{w|Two and a Half Men}}''. Other answers are possible, but only this one fits the next line.
|-
|<tt>a1f9b2b6299e7a2b 617ab0277727ad85</tt>
|best TOS episode
|<tt>{{w|Charlie X|Charlie X}}</tt>
|"{{w|Star Trek: The Original Series|TOS}}" refers to the original series of ''{{w|Star Trek}}''. Although this had dozens of episodes, only one fits the previous line as well as the next line.
|-
|<tt>39738b7adb0b8af7 617ab0277727ad85</tt>
|Sugarland
|<tt>HoustonTX</tt>
|{{w|Sugar Land, Texas|Sugar Land}} is a suburb of {{w|Houston}}, {{w|Texas}}. This fits with the previous line. {{w|Sugarland}} is a band, but it does not fit well with the previous hint, and would not lead to our first guess.
|-
|<tt>1ab29ae86da6e5ca</tt>
|name + jersey#
|<tt>Judith15</tt>
|Even if we knew this user's name, we wouldn't know their jersey number. But the clue 4 lines up already gave us the answer.
|-
|<tt>877ab7889d3862b1</tt>
|alpha
|<tt>abc</tt>
|This password is also far too common, but this clue still isn't enough to narrow it down. Combine with the clue 4 lines below, however, and it's quite easy.
|-
|<tt>877ab7889d3862b1</tt>
|
|<tt>abc</tt>
|No hint, but the same as the surrounding passwords.
|-
|<tt>877ab7889d3862b1</tt>
|
|<tt>abc</tt>
|No hint, but the same as the surrounding passwords.
|-
|<tt>877ab7889d3862b1</tt>
|obvious
|<tt>abc</tt>
|Same as the surrounding passwords.
|-
|<tt>877ab7889d3862b1</tt>
|Michael Jackson
|<tt>abc</tt>
|{{w|Michael Jackson}} did many songs, but only one was {{w|ABC (song)|alphabetical}} (4 lines up).
|-
|<tt>38a7c9279cadeb44 9dca1d79d4dec6d5</tt>
|
|<tt>asdfghjkl</tt>
|No hint, but the same as the one below.
|-
|<tt>38a7c9279cadeb44 9dca1d79d4dec6d5</tt>
|he did the mash, he did the
|<tt>asdfghjkl</tt>
|Probably a "keyboard mash" (e.g. asdfghjkl), a common password. The hint is a reference to the song "{{w|Monster Mash}}" ("He did the mash/He did the monster mash").
|-
|<tt>38a7c9279cadeb44</tt>
|purloined
|<tt>asdfghjk</tt>
|A reference to the {{w|Edgar Allan Poe}} story "{{w|The Purloined Letter}}", this represents all the keys of the home row, or the keyboard mash password, but with one missing("purloined") letter.
|-
|<tt>a8ae5745a2b7af7a 9dca1d79d4dec6d5</tt>
|fav water-3 {{w|List_of_Pokémon|Pokemon}}
|<tt>[http://bulbapedia.bulbagarden.net/wiki/Tentacool_(Pok%C3%A9mon) Tentacool]</tt>
|This is the only [http://bulbapedia.bulbagarden.net/wiki/Water_3_%28Egg_Group%29 water-3] Pokémon with a 9 letter name ending in "l", so it must be this to fit with the password 'asdfghjkl'
|-
|}

==Transcript==
:Hackers recently leaked '''''153 million''''' Adobe user emails, encrypted passwords, and password hints.
:Adobe encrypted the passwords improperly, misusing block-mode 3DES. The result is something wonderful:

<pre>
User password Hint
------------- ----

4e18acc1ab27a2d6 weather vane sword
4e18acc1ab27a2d6
4e18acc1ab27a2d6 a0a2876eb1ea1fca name1
8babb6299e06eb6d duh
8babb6299e06eb6d a0a2876eb1ea1fca
8babb6299e06eb6d 85e9da81a8a78adc 57
4e18acc1ab27a2d6 favorite of 12 apostles
1ab29ae86da6e5ca 7a2d6a0a2876eb1e with your own hand you
have done all this
a1f9b2b6299e7a2b eadec1e6ab797397 sexy earlobes
a1f9b2b6299e7a2b 617ab0277727ad85 best tos episode
39738b7adb0b8af7 617ab0277727ad85 sugarland
1ab29ae86da6e5ca name + jersey#
877ab7889d3862b1 alpha
877ab7889d3862b1
877ab7889d3862b1
877ab7889d3862b1 obvious
877ab7889d3862b1 Michael Jackson
38a7c9279cadeb44 9dca1d79d4dec6d5
38a7c9279cadeb44 9dca1d79d4dec6d5 he did the mash, he did the
38a7c9279cadeb44 purloined
a8ae5745a2b7af7a 9dca1d79d4dec6d5 fav water-3 pokemon
</pre>

:The greatest crossword puzzle in the history of the world

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Pokémon]]
[[Category:Cryptography]]