explain xkcd - User contributions [en]

936: Password Strength

2016-05-25T20:45:01Z

Bpothier: /* External links */ added CMU & Microsoft links

{{comic
| number = 936
| date = August 10, 2011
| title = Password Strength
| image = password strength.png
| titletext = To anyone who understands information theory and security and is in an infuriating argument with someone who does not (possibly involving mixed case), I sincerely apologize.
}}

==Explanation==
This comic is saying that the password in the top frames "Tr0ub4dor&3" is easier for password cracking software to guess because it has less entropy than "correcthorsebatterystaple" and also more difficult for a human to remember, leading to insecure practices like writing the password down on a post-it attached to the monitor.

In simple cases the {{w|Entropy (information theory)|entropy}} of a password is calculated as ''a^b'' where ''a'' is the number of allowed symbols and ''b'' is its length. A dictionary word (however long) has an entropy of around 65000, i.e. 16 bits. A truly random string of length 11 (not like "Tr0ub4dor&3", but more like "J4I/tyJ&Acy") has 94^11 = 72.1 bits. However the comic shows that "Tr0ub4dor&3" has only 28 bits of entropy. Another way of selecting a password is to have 2048 "symbols" (common words) and select only 4 of those symbols. 2048^4 = 44 bits, much better than 28.

It is absolutely true that people make passwords hard to remember because they think they are "safer", and it is certainly true that length, all other things being equal, tends to make for very strong passwords and this can confirmed by using [http://rumkin.com/tools/password/passchk.php rumkin.com's password strength checker]. Even if the individual characters are all limited to [a-z], the exponent implied in "we added another lowercase character, so multiply by 26 again" tends to dominate the results.

In addition to being easier to remember, long strings of lowercase characters are also easier to type on smartphones and {{w|Virtual keyboard|soft keyboards}}.

xkcd's password generation scheme requires the user to have a list of 2048 common words (log2(2048) = 11). For any attack we must assume that the attacker knows our password generation algorithm, but not the exact password. In this case the attacker knows the 2048 words, and knows that we selected 4 words, but not which words. The number of combinations of 4 words from this list of words is (211)4 = 244 bits. For comparison, the [http://world.std.com/~reinhold/dicewarefaq.html#calculatingentropy entropy offered by Diceware's 7776 word list is 13 bits per word]. If the attacker doesn't know the algorithm used, and only knows that lowercase letters are selected, the "common words" password would take even longer to crack than depicted. 25 ''random'' lowercase characters would have [http://www.wolframalpha.com/input/?i=log2%2826^25%29 117 bits of entropy], vs 44 bits for the common words list.

;Example
Below there is a detailed example which shows how different rules of complexity work to generate a password with supposed 44 bits of entropy. The examples of expected passwords were generated in random.org.(*)

If ''n'' is the number of symbols and ''L'' is the length of the password, then ''L'' = 44 / log2(n).

{|class="wikitable"
!Symbols
!Number of symbols
!Minimum length
!colspan="2"|Examples of expected passwords
!Example of an actual password
!Actual bits of entropy
!Comment
|-
|a||26||9.3||mdniclapwz||jxtvesveiv||troubadorx||16+4.7 = 20.7||Extra letter to meet length requirement; log2(26) = 4.7
|-
|rowspan="2"|a 9
|rowspan="2"|36
|rowspan="2"|8.5
|rowspan="2"|qih7cbrmd
|rowspan="2"|ewpltiayq
|tr0ub4d0r||16+3=19||3 = common substitutions in the comic
|-
|troubador1||16+3.3=19.3||log2(10) = 3.3
|-
|a A||52||7.7||jAwwBYne||NeTvgcrq||Troubador||16+1=17||1 = caps? in the comic
|-
|a &||58||7.5||j.h?nv),||c/~/fg\:||troubador&||16+4=20||4 = punctuation in the comic
|-
|a A 9||62||7.3||cDe8CgAf||RONygLMi||Tr0ub4d0r||16+1+3=20||1 = caps?; 3 = common substitutions
|-
|a 9 &||68||7.2||_@~"#^.2||un$l|!f]||tr0ub4d0r&||16+3+4=23||3 = common substitutions; 4 = punctuation
|-
|a A 9 &||94||6.7||Re-:aRo||^$rV{3?||Tr0ub4d0r&||16+1+3+4=24||1 = caps?; 3 = common substitutions; 4 = punctuation
|-
|rowspan="2"|common words
|rowspan="2"|2048
|rowspan="2"|4
|rowspan="2"|reasonableretailsometimespossibly
|rowspan="2"|constantyieldspecifypriority||reasonableretailsometimespossibly||11×4=44||Go to random.org and select 4 random integers between 1 and 2048; then go to your list of common words
|-
|correcthorsebatterystaple
|0
|Because of this comic, this password has no entropy
|}

:a = lowercase letters
:A = uppercase letters
:9 = digits
:& = the 32 special characters in an American keyboard; Randall assumes only the 16 most common characters are used in practice (4 bits)

:(*) The use of random.org explains why <code>jAwwBYne</code> has two consecutive w's, why <code>Re-:aRo</code> has two R's, why <code>_@~"#^.2</code> has no letters, why <code>ewpltiayq</code> has no numbers, why "constant yield" is part of a password, etc. A human would have attempted at passwords that looked random.

==People who don't understand information theory and security==

The title text likely refers to the fact that this comic could cause people who understand information theory and agree with the message of the comic to get into an infuriating argument with people who do not — and disagree with the comic.

If you're confused, don't worry; you're in good company; even security "experts" don't understand the comic:

* Bruce Schneier thinks that dictionary attacks make this method "obsolete", despite the comic ''assuming'' perfect knowledge of the user's dictionary from the get-go. He advocates his own low-entropy "first letters of common plain English phrases" method instead: [https://www.schneier.com/blog/archives/2014/03/choosing_secure_1.html#!s!xkcd Schneier original article] and rebuttals: [http://robinmessage.com/2014/03/why-bruce-schneier-is-wrong-about-passwords/ 1] [http://security.stackexchange.com/a/62881/10616 2] [http://www.reddit.com/r/technology/comments/1yxgqo/bruce_schneier_on_choosing_a_secure_password/cfp2z9k 3] [http://www.reddit.com/r/YouShouldKnow/comments/232uch/ysk_how_to_properly_choose_a_secure_password_the/cgte7lp 4] [http://www.reddit.com/r/YouShouldKnow/comments/232uch/ysk_how_to_properly_choose_a_secure_password_the/cgszp62 5] [http://www.reddit.com/r/YouShouldKnow/comments/232uch/ysk_how_to_properly_choose_a_secure_password_the/cgt6ohq 6]
* Steve Gibson basically gets it, but calculates entropy incorrectly in order to promote his own method and upper-bound password-checking tool: [https://www.grc.com/sn/sn-313.htm#!s!math%20is%20wrong Steve Gibson Security Now transcript] and [https://subrabbit.wordpress.com/2011/08/26/how-much-entropy-in-that-password/ rebuttal]
* Computer security consultant Mark Burnett ''almost'' understands the comic, but then advocates adding numerals and other crud to make passphrases less memorable, missing the point: [https://web.archive.org/web/20150319220514/https://xato.net/passwords/analyzing-the-xkcd-comic/ Analyzing the XKCD Passphrase Comic]
* Ken Grady incorrectly thinks that user-selected sentences like "I have really bright children" have the same entropy as randomly-selected words: [http://blog.hellersearch.com/Blog/bid/141527/Is-Your-Password-Policy-Stupid Is Your Password Policy Stupid?]
* Diogo Mónica doesn't understand that the words have to be truly random, not user-selected, like "let me in facebook": [https://diogomonica.com/posts/password-security-why-the-horse-battery-staple-is-not-correct/ Password Security: Why the horse battery staple is not correct]

Sigh.

==Transcript==
:The comic illustrates the relative strength of passwords assuming basic knowledge of the system used to generate them.
:A set of boxes is used to indicate how many bits of entropy a section of the password provides.
:The comic is laid out with 6 panels arranged in a 3x2 grid.
:On each row, the first panel explains the breakdown of a password, the second panel shows how long it would take for a computer to guess, and the third panel provides an example scene showing someone trying to remember the password.

:[The password "Tr0ub4dor&3" is shown in the center of the panel. A line from each annotation indicates the word section the comment applies to.]

:Uncommon (non-gibberish) base word
:[Highlighting the base word - 16 bits of entropy.]
:Caps?
:[Highlighting the first letter - 1 bit of entropy.]
:Common Substitutions
:[Highlighting the letters 'a' (substituted by '4') and both 'o's (the first of which is substituted by '0') - 3 bits of entropy.]
:Punctuation
:[Highlighting the symbol appended to the word - 4 bits of entropy.]
:Numeral
:[Highlighting the number appended to the word - 3 bits of entropy.]
:Order unknown
:[Highlighting the appended characters - 1 bit of entropy.]
:(You can add a few more bits to account for the fact that this is only one of a few common formats.)

:~28 bits of entropy
:228 = 3 days at 1000 guesses sec
:(Plausible attack on a weak remote web service. Yes, cracking a stolen hash is faster, but it's not what the average user should worry about.)
:Difficulty to guess: Easy.

:[Cueball stands scratching his head trying to remember the password.]
:Cueball: Was it trombone? No, Troubador. And one of the O's was a zero?
:Cueball: And there was some symbol...
:Difficulty to remember: Hard.

:[The passphrase "correct horse battery staple" is shown in the center of the panel.]
:Four random common words {Each word has 11 bits of entropy.}

:~44 bits of entropy
:244 = 550 years at 1000 guesses sec
:Difficulty to guess: Hard.

:[Cueball is thinking, in his thought bubble a horse is standing to one side talking to an off-screen observer. An arrow points to a staple attached to the side of a battery.]
:Horse: That's a battery staple.
:Observer: Correct!
:Difficulty to remember: You've already memorized it

:Through 20 years of effort, we've successfully trained everyone to use passwords that are hard for humans to remember, but easy for computers to guess.

==External links==
*Some info was used from the highest voted answer given to the question of "how accurate is this XKCD comic" at StackExchange [http://security.stackexchange.com/questions/6095/xkcd-936-short-complex-password-or-long-dictionary-passphrase].
*Similarly, a question of "how right this comic is" was made at AskMetaFilter [http://ask.metafilter.com/193052/Oh-Randall-you-do-confound-me-so] and [[Randall]] responded [http://ask.metafilter.com/193052/Oh-Randall-you-do-confound-me-so#2779020 there].
*Also the Wikipedia article on '{{w|Passphrase}}' is useful.
*In case you missed it in the explanation, GRC's Steve Gibson has a fantastic page [https://www.grc.com/haystack.htm] about this (and may have prompted this comic, as his podcast [http://www.grc.com/sn/sn-303.htm] about this was posted the month before this comic).
* This comic inspired [http://blog.acolyer.org/2015/10/29/how-to-memorize-a-random-60-bit-string/ How to memorize a random 60-bit string] scientific paper (link is to the article about paper, wth paper itself linked)
* [https://github.com/dropbox/zxcvbn zxcvbn password strength estimator] thanks this comic for the inspiration in acknowledgements.
* CMU paper: [http://cups.cs.cmu.edu/soups/2012/proceedings/a7_Shay.pdf Correct horse battery staple: Exploring the usability of system-assigned passphrases]
* [http://research.microsoft.com/pubs/265143/Microsoft_Password_Guidance.pdf Microsoft Password Guidance] (page 8)

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

1468: Worrying

2015-02-27T03:01:53Z

Bpothier: /* Table */ - typo

{{comic
| number = 1468
| date = January 2, 2015
| title = Worrying
| image = worrying.png
| titletext = If the breaking news is about an event at a hospital or a lab, move it all the way over to the right.
}}

==Explanation==
This chart is a visual representation of how worried people should be by various events in real life compared to the same events in movies, based on the the likelihood of the event causing serious harm. In effect it's poking fun at various cliches and the emphasis on dramatic flair, regardless of realism. The chart's Y-axis indicates how worrying an event is in real life (from "not very worried" to "very worried"), while its X-axis shows how worrying the event is in movies. Nine events are shown in the chart, all of them cliches in the medium of film:

*'''Spilling a drink on your shirt''': In both real life and in movies, this just causes a stain and maybe a little embarrassment.
*'''Nosebleed''': Nosebleeds are common in real life and almost never are serious...almost. [http://tvtropes.org/pmwiki/pmwiki.php/Main/DeadlyNosebleed Nosebleeds in movies] are almost always a sign that something ''is'' seriously wrong - the common, mundane nosebleeds never come up. In ''Firefly'', the blue hand men use a device that causes a nosebleed followed by massive haemorrhaging and death. Even "mundane" nosebleeds brought on by fisticuffs are a sign that either someone has just lost, [http://tvtropes.org/pmwiki/pmwiki.php/Main/HeroicSecondWind or someone is about to have an adrenaline rush]. This does not always apply to boxing movies where the hero can easily have a massive nosebleed and still win the fight.
*'''Breaking news''': People in real life commonly don't pay much attention to the news at all, so many breaking stories go unnoticed until much later. Most breaking news stories are also about non-threatening events (eg. presidential addresses) or events that are far removed from the viewer. However, in movies, seeing the news station switch to a "breaking news" broadcast is usually a means to introduce a significant plot element that the characters find worrying, and large numbers of people are often shown watching and being emotionally affected by the news while it's breaking. XKCD has referenced [[1387|news reports as foreshadowing before]].
*'''Parking ticket''': Tickets in movies are almost always ignored, but in real life they are moderately worrying because they cost money and can tarnish your driving record.
*'''Persistent cough''': In real life, coughing fits can be a sign of serious illness, but usually aren't. If you have a persistent cough, you should check with a doctor. In movies, just like with nosebleeds, a person with a [http://tvtropes.org/pmwiki/pmwiki.php/Main/IncurableCoughOfDeath persistent cough] is almost always extremely ill or infectious.
*'''"We need to talk."''': This phrase is a common, stereotypical lead-in to a serious conversation, usually about a couple's relationship status, that often causes a high level of worry in the recipient. According to this chart, this phrase is equally worrisome both in movies and in real life.
*'''Getting knocked out by a punch''': In movies, a character who is [http://tvtropes.org/pmwiki/pmwiki.php/Main/TapOnTheHead knocked out by a punch] always wakes up sometime later with no lasting effects, making it less cause for concern than a spilt drink. In real life, however, a person knocked out by a punch can suffer serious brain injuries or even die from the punch itself, or can sustain further injuries from their head hitting the ground.
*'''Chest wounds''': The chart mentions wounds on both your right and left sides. In real life, a chest wound to either side is extremely worrying. But in movies, getting wounded on the right side of the chest will rarely deal lasting damage to the hero or primary villain, to show how badass they are. Wounds on the ''left'' side of the chest signify swift death. This can be explained by the common misconception that the heart is on the left side of the chest - it is actually in the centre, with a slight tendency to the left. However, even left-side chest wounds are apparently still less worrisome than nosebleeds. It must also be noted that the term "chest wound" is more broad than what the author of the comic appears to mean. More narrow terms of "thoracic gunshot wound", "gunshot chest wound", "thoracic ballistic trauma" or "penetrating chest wound" (the latter is slightly broader and includes the damage inflicted by blades and other impaled objects) would be more appropriate, because just a "chest wound" includes such insignificant events as minor skin cuts in the chest area.

The title text expands on the aforementioned breaking news reports. While already overly worrying whenever they occur in movies compared to real life, should the movie's news report cover an event at a hospital (usually an outbreak of some major disease) or a laboratory (a monster escaping, a toxic gas released, an explosion, etc.), these events are universally much more worrisome than any other type of news story since they are guaranteed to be important for the protagonists in short order.

==Table==
The comic shows an X-Y plot of events, showing how worried you should be ''in real life'' on the vertical axis and ''in movies'' on the horizontal axis. The axis goes from "not very worried" to "very worried".

Below is a table listing the coordinate for each event according to how worrying it is. The coordinates have been found by measuring each dot to the two axises and then assuming that the extremes are at 100%.
*Note that this gives two possible ways to interpret the Y-axis "In real life" coordinate.
**Either chest wound is at 100% - this is the first Y-axis coordinate given below under "In real life".
**But alternatively it could be the most worrisome event over all that should be set to 100% including also the most worrisome event on the X-axis for "In movies". In this case the nosebleed event sets the 100% bar higher, thus lowering the percentage for the "In real life" events. Either way could be argued, and thus this other coordinate is given as In Real Life vs. Nose Bleed ('''IRL vs. NB''').
*For the "In movies" coordinate nosebleed is at 100%. However since nosebleed is located past the end of the x-axis arrow it could be argued that it is this event that is off the chart in the movies. But this table will assume this as the 100% mark either over all or at least for the X-axis for "In Movies".

{| class="wikitable sortable"
! In real life !! IRL vs. NB !! In movies !! Event
|-
| 100% || 73% || 30% || Chest wound on your right side
|-
| 100% || 73% || 80% || Chest wound on your left side
|-
| 81% || 59% || 9% || Getting knocked out by a punch
|-
| 75% || 55% || 62% || "We need to talk."
|-
| 51% || 37% || 90% || Persistent cough
|-
| 28% || 20% || 8% || Parking ticket
|-
| 24% || 18% || 74% || Breaking news
|-
| 12% || 8% || 11% || Spilling a drink on your shirt
|-
| 11% || 8% || 100% || Nosebleed
|}

==Transcript==
:'''How worried should you be when various things happen to you:'''
:[A chart with a scatter plot on which 9 dots are labeled. Each axis have a title and a scale. Reading from the top to the bottom and then left to right along the axis are:]
:Very worried
:'''...In Real Life'''
:Not very worried

:Not very worried
:'''...In Movies'''
:Very worried

:[The labels in the chart from the top:]
:[This first entry is standing in the middle of a square bracket that points to the two next entires both of which are at the same level:]
:Chest wound
:...on your right side
:...on your left side
:Getting knocked out by a punch
:"We need to talk."
:Persistent cough
:Parking ticket
:Breaking news
:Spilling a drink on your shirt
:Nosebleed

{{comic discussion}}
[[Category:Charts]]

1427: iOS Keyboard

2014-11-10T19:29:16Z

Bpothier: /* Explanation */ I forgot http in link.. :(

{{comic
| number = 1427
| date = September 29, 2014
| title = iOS Keyboard
| image = ios_keyboard.png
| titletext = More actual results: 'Hello. My name is Inigo Montoya. You [are the best. The best thing ever]', 'Revenge is a dish best served [by a group of people in my room]', and 'They may take our lives, but they'll never take our [money].'
}}

==Explanation==
It looks like [[Randall]] has been playing with his Apple device after installing the recently released {{w|iOS 8}} update. The comic is referencing the autocomplete function on the iOS virtual keyboard (aka [[1031:_s/keyboard/leopard/|leopard]]). A comparable feature is also available on other operating systems, like Android. When the phrase, for example, "Revenge is a dish best served" is typed, the keyboard will suggest “by” followed by “a” then “group” and so on.

The following movies are referenced:

{| class="wikitable"
! Movie
! Character & Situation
! Full Quote
|-
|[http://www.imdb.com/character/ch0026631/quotes Sherlock Holmes]
|Sherlock Holmes explaining his deductions to his assistant, Watson
|"Elementary, my dear Watson." (paraphrased in several movies, never actually used {{w|Sherlock_Holmes#.22Elementary.2C_my_dear_Watson.22|in the books}})
|-
|[http://www.imdb.com/title/tt0086250/quotes Scarface (1983)]
|Scarface is holding an M16, defending his house from Sosa's gunmen, shouting to attackers.
|"You wanna fuck with me? Okay. You wanna play rough? Okay. Say hello to my little friend!"
|-
|[http://www.imdb.com/title/tt0032138/quotes The Wizard of Oz (1939)]
|Dorothy with her dog, Toto, in munchkin land.
|"Toto, I've a feeling we're not in Kansas anymore."
|-
|[http://www.imdb.com/character/ch0000007/quotes James Bond]
|Bond introducing himself, while holding trademark martini.
|"Bond, James Bond." (nothing follows).
|-
|[http://www.imdb.com/title/tt0379786/quotes Serenity (2005)]
|Wash, at the controls of Serenity.
|"I am a leaf on the wind - watch how I soar."
|-
|[http://www.imdb.com/title/tt0089218/quotes The Goonies (1985)]
|Mikey standing at the pool in the wishing well, encouraging his troop of misfits to continue on their journey.
|"Goonies never say die!"
|-
|[http://www.imdb.com/title/tt0120737/quotes The Lord of The Rings: The Fellowship of the Ring (2001)]
|Aragorn, Legolas & Gimli pledge allegiance to protect the ring bearer on their mission to destroy the ring.
|Aragorn: "If by my life or death I can protect you, I will. You have my sword." Legolas: "And you have my bow." Gimli: "And *my* axe."
|-
|[http://www.imdb.com/title/tt0093779/quotes The Princess Bride (1987)]
|Inigo Montoya facing the six fingered man, the man he swore a vendetta against for killing his dad.
|"Hello. My name is Inigo Montoya. You killed my father. Prepare to die."
|-
|[http://www.imdb.com/title/tt0084726/ Star Trek: The Wrath of Khan (1982)]
|Khan paraphrasing Shakespeare to justify his vengeance.
|{{w|Revenge#Proverbs|"Revenge is a dish best served cold"}} (e.g. [http://www.imdb.com/title/tt0084726/quotes Star Trek: The Wrath of Khan (1982)]: Khan: "...do you know the Klingon proverb that tells us revenge is a dish that is best served cold?")
|-
|[http://www.imdb.com/title/tt0112573/quotes Braveheart (1995)]
|Wallace rallying his Scottish army before a seemingly hopeless battle against the British.
|"They may take our lives, but they'll never take... OUR FREEDOM!"
|}

An older comic [[1068: Swiftkey]] is also about keyboard predictions, but without any preceding text (by the Swiftkey keyboard application instead of the iOS 8 keyboard).

==Transcript==
:[Headline]
:'''Movie quotes'''
:[Top picture shows a line typed on an iPhone]
:Elementary, my dear
:[Then the next line shows the words suggested by the virtual keyboard]
:Friend | Lord | Friends
:[Below are the visible part of keyboard. In the second line only the top of the letters can be seen]
:QWERTYUIOP
:ASDFGHJKL
:[Below is a new sub heading above six pictures arranged in two rows]
:According to iOS 8 keyboard predictions
:[For each of the six pictures a part of the text is black, and the other part is light grey. Below the black text is written in bold letters.]
:[Picture 1: Cueball stands with a machinegun]
:Cueball: '''Say hello to my little''' sister and my mom and my dad and my friends
:[Picture 2: A girl stands next to her dog with a basket]
:Girl: '''Toto, I've a feeling we're not''' going to the gym today
:[Picture 3: Bond talks to Megan]
:James Bond: '''Bond, James Bond''' yields
:[Picture 4: A pilot operates his plane and talks to Cueball behind him]
:Pilot: '''I'm a leaf on the wind. Watch''' me play the piano
:[Picture 5: A guy with dark hair stands behind a jagged edge]
:Goonie: '''Goonies never say''' anything
:[Picture 6: A dwarf with long beard and helmet stands with an axe]
:Off panel left: '''You have my sword.'''
:Off panel right: '''And my bow.'''
:Dwarf: '''And my''' dad

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

1427: iOS Keyboard

2014-11-10T18:58:22Z

Bpothier: /* Explanation */ typo and re-wikifying some links

{{comic
| number = 1427
| date = September 29, 2014
| title = iOS Keyboard
| image = ios_keyboard.png
| titletext = More actual results: 'Hello. My name is Inigo Montoya. You [are the best. The best thing ever]', 'Revenge is a dish best served [by a group of people in my room]', and 'They may take our lives, but they'll never take our [money].'
}}

==Explanation==
It looks like [[Randall]] has been playing with his Apple device after installing the recently released {{w|iOS 8}} update. The comic is referencing the autocomplete function on the iOS virtual keyboard (aka [[1031:_s/keyboard/leopard/|leopard]]). A comparable feature is also available on other operating systems, like Android. When the phrase, for example, "Revenge is a dish best served" is typed, the keyboard will suggest “by” followed by “a” then “group” and so on.

The following movies are referenced:

{| class="wikitable"
! Movie
! Character & Situation
! Full Quote
|-
|[http://www.imdb.com/character/ch0026631/quotes Sherlock Holmes]
|Sherlock Holmes explaining his deductions to his assistant, Watson
|"Elementary, my dear Watson." (paraphrased in several movies, never actually used {{w|Sherlock_Holmes#.22Elementary.2C_my_dear_Watson.22|in the books}})
|-
|[http://www.imdb.com/title/tt0086250/quotes Scarface (1983)]
|Scarface is holding an M16, defending his house from Sosa's gunmen, shouting to attackers.
|"You wanna fuck with me? Okay. You wanna play rough? Okay. Say hello to my little friend!"
|-
|[http://www.imdb.com/title/tt0032138/quotes The Wizard of Oz (1939)]
|Dorothy with her dog, Toto, in munchkin land.
|"Toto, I've a feeling we're not in Kansas anymore."
|-
|[http://www.imdb.com/character/ch0000007/quotes James Bond]
|Bond introducing himself, while holding trademark martini.
|"Bond, James Bond." (nothing follows).
|-
|[http://www.imdb.com/title/tt0379786/quotes Serenity (2005)]
|Wash, at the controls of Serenity.
|"I am a leaf on the wind - watch how I soar."
|-
|[http://www.imdb.com/title/tt0089218/quotes The Goonies (1985)]
|Mikey standing at the pool in the wishing well, encouraging his troop of misfits to continue on their journey.
|"Goonies never say die!"
|-
|[http://www.imdb.com/title/tt0120737/quotes The Lord of The Rings: The Fellowship of the Ring (2001)]
|Aragorn, Legolas & Gimli pledge allegiance to protect the ring bearer on their mission to destroy the ring.
|Aragorn: "If by my life or death I can protect you, I will. You have my sword." Legolas: "And you have my bow." Gimli: "And *my* axe."
|-
|[http://www.imdb.com/title/tt0093779/quotes The Princess Bride (1987)]
|Inigo Montoya facing the six fingered man, the man he swore a vendetta against for killing his dad.
|"Hello. My name is Inigo Montoya. You killed my father. Prepare to die."
|-
|[www.imdb.com/title/tt0084726/ Star Trek: The Wrath of Khan (1982)]
|Khan paraphrasing Shakespeare to justify his vengeance.
|{{w|Revenge#Proverbs|"Revenge is a dish best served cold"}} (e.g. [http://www.imdb.com/title/tt0084726/quotes Star Trek: The Wrath of Khan (1982)]: Khan: "...do you know the Klingon proverb that tells us revenge is a dish that is best served cold?")
|-
|[http://www.imdb.com/title/tt0112573/quotes Braveheart (1995)]
|Wallace rallying his Scottish army before a seemingly hopeless battle against the British.
|"They may take our lives, but they'll never take... OUR FREEDOM!"
|}

An older comic [[1068: Swiftkey]] is also about keyboard predictions, but without any preceding text (by the Swiftkey keyboard application instead of the iOS 8 keyboard).

==Transcript==
:[Headline]
:'''Movie quotes'''
:[Top picture shows a line typed on an iPhone]
:Elementary, my dear
:[Then the next line shows the words suggested by the virtual keyboard]
:Friend | Lord | Friends
:[Below are the visible part of keyboard. In the second line only the top of the letters can be seen]
:QWERTYUIOP
:ASDFGHJKL
:[Below is a new sub heading above six pictures arranged in two rows]
:According to iOS 8 keyboard predictions
:[For each of the six pictures a part of the text is black, and the other part is light grey. Below the black text is written in bold letters.]
:[Picture 1: Cueball stands with a machinegun]
:Cueball: '''Say hello to my little''' sister and my mom and my dad and my friends
:[Picture 2: A girl stands next to her dog with a basket]
:Girl: '''Toto, I've a feeling we're not''' going to the gym today
:[Picture 3: Bond talks to Megan]
:James Bond: '''Bond, James Bond''' yields
:[Picture 4: A pilot operates his plane and talks to Cueball behind him]
:Pilot: '''I'm a leaf on the wind. Watch''' me play the piano
:[Picture 5: A guy with dark hair stands behind a jagged edge]
:Goonie: '''Goonies never say''' anything
:[Picture 6: A dwarf with long beard and helmet stands with an axe]
:Off panel left: '''You have my sword.'''
:Off panel right: '''And my bow.'''
:Dwarf: '''And my''' dad

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

1413: Suddenly Popular

2014-10-29T00:28:09Z

Bpothier: /* List of the phrases */ fixed Idaho placement in sentence

{{comic
| number = 1413
| date = August 27, 2014
| title = Suddenly Popular
| image = suddenly_popular.png
| titletext = Are Your Teens Practicing Amplexus? Learn These Six Telltale Signs!
}}

==Explanation==

Many phrases that used to be of mainly academic interest become popular when an important event or global trend is described with such phrases in the media. [[Randall]] presents a timeline of past examples, and predicts phrases that may be popularised in the near future. The past events are a mix of buzz words and words learned through disasters, crime and terrorism. The future events seem to be all related to natural disasters or other kinds of serious issues, except ''{{w|Amplexus}}'' — which is the joke of the title text — showing that no matter how many disasters there are, people are generally more concerned about their teenagers' sex lives.

The title text is also an example of a {{w|clickbait}} headline. Many organizations will post a link on social media to their content with a sensationalized headline in order to draw readers in. In this case, the headline is geared towards parents who are worried about their children being sexually active in this new ''Amplexus'' way. Such headlines are the internet's analog to television news' {{w|Promo (media)|promos}} ("A new trend among teens is sweeping the nation, but is it dangerous? Details at 11:00.").

{{w|Global catastrophic risks|Global catastrophic risk}} is a theme throughout this comic. Randall predicts a large asteroid impact/near miss and a volcanic eruption, followed by an {{w|impact winter}} or {{w|volcanic winter}}. An insect borne, global pandemic without a cure also strikes, and then the {{w|technological singularity}} occurs.

This comic has similar features to [[887: Future Timeline]].

==List of the phrases==
Below the phrases are listed with the closest year from the time-line noted behind the phrase. Note that this year does not necessarily match with the in-real-life relevant year. This may be found in the explanation of the phrase below. [https://books.google.com/ngrams/graph?content=world+wide+web%2Cdna+evidence%2Cmilitia+movement%2Csupermax%2Cbutterfly+ballot%2Cal-qaeda%2Cwi-fi%2Ctsunami%2Cviral%2Cradicalize%2Cmetadata&case_insensitive=on&year_start=1900&year_end=2008&corpus=15&smoothing=0&share=&direct_url=t4%3B%2Cworld%20wide%20web%3B%2Cc0%3B%2Cs0%3B%3BWorld%20Wide%20Web%3B%2Cc0%3B%3Bworld%20wide%20web%3B%2Cc0%3B%3BWORLD%20WIDE%20WEB%3B%2Cc0%3B.t4%3B%2Cdna%20evidence%3B%2Cc0%3B%2Cs0%3B%3BDNA%20evidence%3B%2Cc0%3B%3BDNA%20Evidence%3B%2Cc0%3B.t4%3B%2Cmilitia%20movement%3B%2Cc0%3B%2Cs0%3B%3Bmilitia%20movement%3B%2Cc0%3B%3BMilitia%20Movement%3B%2Cc0%3B%3BMilitia%20movement%3B%2Cc0%3B.t4%3B%2Csupermax%3B%2Cc0%3B%2Cs0%3B%3Bsupermax%3B%2Cc0%3B%3BSupermax%3B%2Cc0%3B%3BSUPERMAX%3B%2Cc0%3B%3BSuperMax%3B%2Cc0%3B.t4%3B%2Cbutterfly%20ballot%3B%2Cc0%3B%2Cs0%3B%3Bbutterfly%20ballot%3B%2Cc0%3B%3BButterfly%20Ballot%3B%2Cc0%3B%3BButterfly%20ballot%3B%2Cc0%3B.t4%3B%2Cal%20-%20qaeda%3B%2Cc0%3B%2Cs0%3B%3Bal%20-%20Qaeda%3B%2Cc0%3B%3BAl%20-%20Qaeda%3B%2Cc0%3B.t4%3B%2Cwi%20-%20fi%3B%2Cc0%3B%2Cs0%3B%3BWi%20-%20Fi%3B%2Cc0%3B%3Bwi%20-%20fi%3B%2Cc0%3B.t4%3B%2Ctsunami%3B%2Cc0%3B%2Cs0%3B%3Btsunami%3B%2Cc0%3B%3BTsunami%3B%2Cc0%3B%3BTSUNAMI%3B%2Cc0%3B.t4%3B%2Cviral%3B%2Cc0%3B%2Cs0%3B%3Bviral%3B%2Cc0%3B%3BViral%3B%2Cc0%3B%3BVIRAL%3B%2Cc0%3B.t4%3B%2Cradicalize%3B%2Cc0%3B%2Cs0%3B%3Bradicalize%3B%2Cc0%3B%3BRadicalize%3B%2Cc0%3B.t4%3B%2Cmetadata%3B%2Cc0%3B%2Cs0%3B%3Bmetadata%3B%2Cc0%3B%3BMetadata%3B%2Cc0 Google Books Ngram Viewer] can show the relative frequency of those words in function of the year.

; {{w|World Wide Web}} – 1994
: Though first proposed in 1989, and the first test being completed in 1990, it took until around 1994 for the {{w|World Wide Web|world wide web}} to start becoming well known.

; {{w|DNA profiling|DNA Evidence}} – 1995
: Prominent coverage of the {{w|O. J. Simpson murder trial}} in 1994 brought widespread discussion of {{w|DNA profiling|DNA Evidence}}, making it famous and showing its limitations.

; {{w|Militia Movement}} – 1996
: After the standoffs at {{w|Ruby Ridge}}, Idaho in 1992 and the {{w|Branch Davidians}} compound in Waco, Texas between U.S. Government Agencies and militias in 1993, people started becoming more aware of their presence, culminating with the 1995 {{w|Oklahoma City Bombing}} on the second anniversary of the fire at the Branch Davidians compound.

; {{w|Supermax prison|Supermax}} – 1997
: Super-Maximum security prisons. Possibly referring to the 1997 film {{w|Con Air}}, starring Nicolas Cage, John Cusack, and John Malkovich, in which prisoners being transferred to a new Supermax prison seize control of their transport plane. Also possibly referring to {{w|Timothy McVeigh}} and {{w|Terry Nichols}}, perpetrators of the aforementioned Oklahoma City bombing, who were incarcerated at {{w|ADX Florence}}, the former from the time of his arrest to 1999, and the latter from the time of his conviction to the present day.

[[File:Butterfly Voters View.jpg|thumb|A butterfly ballot]]
; {{w|butterfly ballot|Butterfly Ballot}} – 2000
: In the {{w|United States presidential election in Florida, 2000|United States presidential election in 2000, Florida}} had a major recount dispute that took center stage in the election. Thus, the outcome of the 2000 United States presidential election was not known for more than a month after balloting, because of the extended process of counting and then recounting of Florida presidential ballots. The {{w|butterfly ballot}} was the type of ballot design {{w|United States presidential election in Florida, 2000#Palm Beach County's butterfly ballots|used in Palm Beach County, Florida}}, and was a central issue in the election controversy. Evidence suggests that many voters who intended to vote for Gore or Bush actually marked their ballots for Pat Buchanan or spoiled their ballots, because of a confusing layout of the ballot.

; {{w|Al-Qaeda}} – 2002
: The {{w|September 11th terrorist attacks}} brought the al-Qaeda terrorist organisation into the spotlight almost overnight.

; {{w|Wi-Fi}} – 2003
: Wi-Fi, though developed in the 1990s, first became popular in the early 2000s.

; {{w|Tsunami}} – 2006
: There were a number of tsunamis around this time period, in particular the {{w|Boxing Day Tsunami}} which caused 230,000 deaths, and the {{w|2006 Pangandaran earthquake and tsunami}}. These were some of the first tsunamis to be widely captured on camera, bringing these previously obscure seismic events into the public eye.

; {{w|Viral}} – 2009
: In this context, the word viral is used to describe anything which spreads rapidly and widely on the internet. In particular an online video clip is said to have 'Gone Viral' or become a {{w|Viral video}} if it racks up a high number of views over a short time. This phenomenon has become especially prevalent due to users sharing content on {{w|Social media}}.

; {{w|Radicalization|Radicalize}} – 2011
: Due to the ongoing {{w|Syrian Civil War}}, and the relative ease with which one can travel from Europe to Syria by way of Turkey, there is growing concern about the risk of young Muslims in Europe (and, to a lesser extent, the United States) becoming {{w|radicalization|radicalized}} by indoctrination from fundamentalists either in their communities or on the Internet.

; {{w|Metadata}} – 2013
: Following the highly publicised 2013 leaks by {{w|Edward Snowden}} of information regarding the {{w|NSA}}'s indiscriminate surveillance of global communication metadata, awareness of the privacy value of such data became widespread, where once it was mostly familiar to IT professionals.

''From this point on, phrases were in the future at the time of publication.''

; {{w|Lahar}} – 2016
: A lahar is a mudslide caused by the eruption of a volcano that was covered with snow or ice. Randall is speculating on a future natural disaster being caused by such an incident. {{w|Bárðarbunga}} volcano covered with the {{w|Vatnajökull}} glacier on Iceland increased activity just a few days before publishing of this comic and may erupt in the near future.

; {{w|Insect-borne disease|Insect-Borne}} – 2019
: Some {{w|Category:Insect-borne diseases|diseases are insect-borne}}, meaning specific species of insects are the main vector in spreading to humans. {{w|Malaria}} is an example of an {{w|insect-borne disease}}. Randall predicts some deadly insect-borne disease will emerge around this time.

; {{w|Earth-crosser|Earth-Crossing}} – 2021
: Earth-crossers are asteroids that cross the orbit of Earth. Most of them remain harmless because their orbit doesn't actually intersect the earth's orbit in 3 dimensions, or for the foreseeable future, they will cross when Earth is not there. For this phrase to become popular, an Earth-crosser might have to reach the heretofore-unreached "threatening" level, rating a 5 or more on the {{w|Torino Scale}}, due to a significant chance of a large impact. As of 2014, there are no threats of that level known in the early 2020s. If the next two phrases are connected to this one, Randall is predicting a significant asteroid impact.

; {{w|Thermohaline circulation|Thermohaline}} – 2022
: Thermohaline circulation is the largest group of interconnected ocean currents, which stabilize global climate by equalizing the temperature and salinity of oceans around the world. If this phrase becomes popular, it implies the thermohaline circulation would have slowed or changed significantly. This might be caused by asteroid impact or by polar ice melting. The latter scenario was apocalyptically dramatized in the movie {{w|The Day After Tomorrow}}.

; {{w|Snow blindness|Snow-Blindness}} – 2024
: Snow blindness is an eye condition caused by excessive UV light reflected from snow and ice. This can lead to corneal damage and blindness (temporary, if treated properly). This phrase becoming popular might suggest a long {{w|impact winter}} (from the asteroid) or severe {{w|ozone depletion}} in cold regions of the world.

; {{w|Amplexus}} – 2025
: A form of non-penetrative reproduction carried out by some animals, for example frogs, involving grasping the partner with front legs. This may be connected to the other posts (some change in human society) or it may simply be a joke at how new sexual language/fads appear and hit mainstream media from time to time (for example a number of acts gained fame from Sex and the City). This also ties in with the title text, which imagines a sensationalist headline suggesting teenagers may be doing this.

; {{w|Aquaplaning|Controlled Hydroplaning}} – 2028
: Hydroplaning occurs when a vehicle tire comes in contact with a puddle in such a way that the water builds up between the tire and the road surface. The film of water, having a much lower coefficient of friction than the road surface, causes the tire to lose traction. Typically, in this scenario, the driver isn't planning to hydroplane and loses control of the vehicle. In theory, controlled hydroplaning would be achieved when the driver plans for it ahead of time. This could be necessary if, in this hypothetical future, most of the roads are flooded since the impact winter (after only four years) ends and thus a great thaw causes all roads to become wet all the time.

; {{w|Paradoxical reaction|Paradoxical Reaction}} – 2031
: "paradoxical reaction" is a medical term for when the outcome of a medical treatment, typically the taking of a drug, is the opposite of that expected. For example if taking a pain relieving medication made the pain worse. For this term to suddenly become well known, a large scale or particularly notable case must have taken place (such as the insect-borne disease of 2019). Or, this and the following (and maybe the last as well) phrases may refer to the events from {{w|The Evitable Conflict}} by Isaac Asimov (and its very loose but much more popular film adaptation {{w|I,_Robot_(film)|I, Robot}}) where robots, instructed with the {{w|Three Laws of Robotics}}, take over the world to prevent humans hurting each other. The paradoxical reaction is that these laws were specifically designed to, among other things, prevent robots from taking over the world in the first place.

; {{w|Desertion|Drone Desertion}} – 2033
: Desertion is the abandonment of a post or duty, usually military in nature. With the increasing use of autonomous drones by the military this hints at an event where drones 'decide' to desert, possibly due to unspecified advances in {{w|Artificial Intelligence}} and {{w|Robot Rights}}. Or maybe they just start following the {{w|Three Laws of Robotics}}.

; {{w|Human hair growth|Rapid Hair Growth}} – 2034
: Maybe some humans have developed a very rapid hair growth (presumably on the entire body) caused by the cold years of the impact winter.

; {{w|Oath#Divine oath|I Swear Allegiance To The God-Empress In Life And In Death}} – 2038
: This is a {{w|Oath#Divine oath|divine oath}}. A possible explanation is that after the impact and the desertion of the drones predicted for 2033, a strong fraction has made their leader divine, and everyone now has to swear allegiance to this new God-Empress using this phrase - which would certainly make it a very "popular" phrase. The phrase [http://tvtropes.org/pmwiki/pmwiki.php/Main/GodEmperor God-Emperor] was popularized in the science-fiction work ''Dune'' in 1965 and has been repeatedly referenced since, notably in the tabletop game Warhammer 40,000 and the computer game Starcraft (and their related media).

==Transcript==
:Obscure words and phrases everyone suddenly becomes very familiar with.
:[A time line to the left is marked of by several phrases to the right around the time they became familiar to the public:]
::<-- World Wide Web
::<-- DNA Evidence
:1995
::<-- Militia Movement
::<-- Supermax
:2000
::<-- Butterfly Ballot
::<-- Al-Qaeda
::<-- Wi-Fi
:2005
::<-- Tsunami
::<-- Viral
:2010
::<-- Radicalize
::<-- Metadata
:2015
::<-- Lahar
::<-- Insect-Borne
:2020
::<-- Earth-Crossing
::<-- Thermohaline
::<-- Snow-Blindness
:2025
::<-- Amplexus
::<-- Controlled Hydroplaning
:2030
::<-- Paradoxical Reaction
::<-- Drone Desertion
::<-- Rapid Hair Growth
:2035
::<-- I Swear Allegiance To The God-Empress In Life And In Death
:2040

{{comic discussion}}
[[Category:Charts]]

1412: Teenage Mutant Ninja Turtles

2014-10-29T00:14:41Z

Bpothier: /* Explanation */ Added Jimmy Fallon 80s medley reference

{{comic
| number = 1412
| date = August 25, 2014
| title = Teenage Mutant Ninja Turtles
| image = teenage_mutant_ninja_turtles.png
| titletext = My upcoming album, 'Linked List', has covers of 'The Purple People Eater', the Ninja Turtles theme, 'Itsy Bitsy Teenie Weenie Yellow Polka Dot Bikini', and the Power Rangers theme, with every song played to the tune of the next.
}}

== Explanation ==
{{incomplete| Are there other references to earlier comics in the article titles than the one mentioned in the wiki links section?}}
This comic is a reference to the recently released {{w|Teenage Mutant Ninja Turtles (2014 film)|Teenage Mutant Ninja Turtles movie}}. It is a list of Wikipedia article titles that are in the the same syllable-stress pattern as the first line of the [https://www.youtube.com/watch?v=rS-qFdw-v_o theme song] of the {{w|Teenage Mutant Ninja Turtles (1987 TV series)|1987 cartoon series}}.

The list is compiled in alphabetical order from top to bottom, without respect to the left or right column. Some of the items on this list (e.g. ''{{w|Ace Ventura: Pet Detective}}'') are drawn as headlines in the same style as the logo from that series. These articles are not in alphabetical order with the surrounding small face text, but these headlines are in alphabetical order with the other headlines from top to bottom, without respect to the left or right column. Some of these phrases are not actually the titles of Wikipedia articles, but rather the full names given in articles' lead sentences. For instance, the article on {{w|Woody Guthrie|Woodrow Wilson "Woody" Guthrie}} appears under the title Woody Guthrie.

The syllable-stress pattern of this line is long-short-long-short-long-short-long-short, known in poetry as {{w|trochaic tetrameter}}. Randall has previously authored comics dealing with {{w|trochees}}, namely [[856: Trochee Fixation]] and [[1383: Magic Words]].

A similar idea was performed by {{w|Jimmy Fallon}} in 2001 at a [https://www.youtube.com/results?search_query=jimmy+fallon+80s+medley concert for New York city] where he demonstrated singing "any 80's song" over the tune of {{w|MC Hammer}}'s song "{{w|U Can't Touch This}}".

The title text suggests an album of songs (''{{w|The Purple People Eater}}'', the aforementioned ''Ninja Turtles'' theme, ''{{w|Itsy Bitsy Teenie Weenie Yellow Polka Dot Bikini}}'' and the ''{{w|Mighty Morphin' Power Rangers}}'' theme), the title or primary refrain of which have a large number of verses in {{w|trochee|trochaic}} {{w|meter (poetry)|meter}}. Randall suggests that these refrains are so interchangeable that the lyrics of each could be sung to the melody of the song following it in the tracklist. Randall would title the album ''{{w|Linked List}}'' as each song would melodically reference the next song. The refrains of the songs, respectively are:
*"One-eyed, one-horned flying purple people eater"
*"Teenage Mutant Ninja Turtles"
*"Itsy Bitsy Teenie Weenie Yellow Polka Dot Bikini"
*"Go go Power Rangers"

== The Wikipedia links ==

There are 6 headlines and 9 other article links in each block next to a headline for a total of 60 wiki links:

{| class="wikitable"
|-
|
{{w|Ace Ventura: Pet Detective}}
|
#{{w|Biggest Loser: Second Chances}}
#{{w|Cayman Island blue iguana}}
#{{w|Central Texas pocket gopher}}
#{{w|Church of Jesus Christ Creator}}
#{{w|Climate change and meat production}}
#{{w|Crouching Tiger, Hidden Dragon}}
#{{w|Daylight saving time in China}}
#{{w|Denver Airport People Mover}}
#{{w|Easter Island spiny lobster}}
|-
|
#{{w|Edgar Allan Poe Museum}}
#{{w|Engine failure after take-off}}
#{{w|English as a second language}}
#{{w|Former Arctic Monkeys members}}
#{{w|Fowler's Modern English Usage}}
#{{w|Georgia Game and Fish Department}}
#{{w|Golden-mantled howler monkey}}
#{{w|Greater Cleveland Film Commission}}
#{{w|Hairy flower chafer beetle}}
|
{{w|Asian Human Rights Commission}}
|-
|
{{w|San Diego City Council}}
|
#{{w|Harland David "Colonel" Sanders}}
#{{w|Human Tissue Resource Network}}
#{{w|Klondike-class destroyer tender|Klondike class destroyer tender}}
#{{w|Legal code of North Dakota}}
#{{w|Lesser knapweed flower weevil}}
#{{w|Lockheed Martin Atlas rocket}}
#{{w|Maple syrup urine syndrome}}
#{{w|Mighty Morphin Power Rangers|Mighty Morphin' Power Rangers}}
#{{w|Nablus mask-like facial syndrome}}
|-
|
#{{w|Neo Geo Pocket Color}}
#{{w|New Year's Eve with Carson Daly}}
#{{w|Newton's second law of motion}}
#{{w|North Korean Workers Party}}
#{{w|Orange County Business Council}}
#{{w|Over/under cable coiling}}
#{{w|Peter Peter Pumpkin Eater}}
#{{w|Places named for Adolf Hitler}}
#{{w|Proton-proton chain reaction}}
|
{{w|Single payer health insurance}}
|-
|
{{w|Spotted giant flying squirrel}}
|
#{{w|Puerto Rican lizard-cuckoo}}
#{{w|Quantum vacuum plasma thruster|Quantuum vacuum plasma thruster}}<ref>See also [[1404: Quantum Vacuum Virtual Plasma]].</ref>
#{{w|Rocky Mountain spotted fever}}
#{{w|Royal Flying Doctor Service}}
#{{w|Russian Women's Fascist Movement}}
#{{w|Semi-active laser guidance}}
#{{w|Seven Brides for Seven Brothers}}
#{{w|Sherlock Holmes: A Game of Shadows}}
#{{w|Six Degrees of Kevin Bacon}}
|-
|
#{{w|Trailing suction hopper dredger}}
#{{w|Vector graphics markup language}}
#{{w|Viti Levu giant pigeon}}
#{{w|Voting rights in Puerto Rico}}
#{{w|William Henry, Duke of Gloucester}}<ref>Gloucester is pronounced /ˈglɒstər/ (gloster).</ref>
#{{w|Windows Vista startup process}}
#{{w|Woodrow Wilson "Woody" Guthrie}}
#{{w|Yaba monkey tumor virus}}
#{{w|Zack and Miri Make a Porno}}
|
{{w|Women science fiction authors}}
|}

=== Notes ===

<references/>

== Trivia ==
* Randall mistyped the word "album" as "alubm" in the original title text but it was fixed later.
* He did not correct the word Quantum, which is mistyped Quantuum in the comic.

== Transcript ==
:{| class="wikitable"
!colspan="2"|
:'''WIKIPEDIA ARTICLE TITLES'''
:With the right syllable stress pattern
:to be sung to the tune of the original
:''Teenage Mutant Ninja Turtles'' theme song
:
|- style="vertical-align:top;"
| style="text-align:right;" |
:'''''Ace Ventura: Pet Detective'''''
| style="text-align:left;" |
:''Biggest Loser: Second Chances''
:Cayman Island blue iguana
:Central Texas pocket gopher
:Church of Jesus Christ Creator
:Climate change and meat production
:''Crouching Tiger, Hidden Dragon''
:Daylight saving time in China
:Denver Airport People Mover
:Easter Island spiny lobster
|- style="vertical-align:top;"
| style="text-align:right;" |
:Edgar Allan Poe Museum
:Engine failure after take-off
:English as a second language
:Former ''Arctic Monkeys'' members
:''Fowler's Modern English Usage''
:Georgia Game and Fish Department
:Golden-mantled howler monkey
:Greater Cleveland Film Commission
:Hairy flower chafer beetle
| style="text-align:left;" |
:'''Asian Human Rights Commission'''
|- style="vertical-align:top;"
| style="text-align:right;" |
:'''San Diego City Council'''
| style="text-align:left;" |
:Harland David "Colonel" Sanders
:Human Tissue Resource Network
:''Klondike''-class destroyer tender
:Legal code of North Dakota
:Lesser knapweed flower weevil
:Lockheed Martin Atlas rocket
:Maple syrup urine syndrome
:''Mighty Morphin' Power Rangers''
:Nablus mask-like facial syndrome
|- style="vertical-align:top;"
| style="text-align:right;" |
:Neo Geo Pocket Color
:''New Year's Eve with Carson Daly''
:Newton's second law of motion
:North Korean Workers Party
:Orange County Business Council
:Over/under cable coiling
:Peter Peter Pumpkin Eater
:Places named for Adolf Hitler
:Proton-proton chain reaction
| style="text-align:left;" |
:'''Single payer health insurance'''
|- style="vertical-align:top;"
| style="text-align:right;" |
:'''Spotted giant flying squirrel'''
| style="text-align:right;" |
:Puerto Rican lizard-cuckoo
:Quantuum vacuum plasma thruster
:Rocky Mountain spotted fever
:Royal Flying Doctor Service
:Russian Women's Fascist Movement
:Semi-active laser guidance
:''Seven Brides for Seven Brothers''
:''Sherlock Holmes: A Game of Shadows''
:Six Degrees of Kevin Bacon
|- style="vertical-align:top;"
| style="text-align:left;" |
:Trailing suction hopper dredger
:Vector graphics markup language
:Viti Levu giant pigeon
:Voting rights in Puerto Rico
:William Henry, Duke of Gloucester
:Windows Vista startup process
:Woodrow Wilson "Woody" Guthrie
:Yaba monkey tumor virus
:''Zack and Miri Make a Porno''
| style="text-align:right;" |
:'''Women science fiction authors'''
|}

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Wikipedia]]
[[Category:Language]]
[[Category:Songs]]

Talk:1401: New

2014-10-28T22:34:20Z

Bpothier:

Why are there three ''n'''s in ''headcannnon'' in the title text?
[[User:Keavon|Keavon]] ([[User talk:Keavon|talk]])

:Or as n increases the effort to convince others that the existence/correctness of headca(n)+on decreases? [[Special:Contributions/108.162.216.26|108.162.216.26]] 20:31, 30 July 2014 (UTC)arcturius

:I think it's as simple as 1 n in canon (what the pun is based on), 2 n's in cannon (in the comic), and just to keep the pattern going, 3 n's in cannnon (in the title text).--[[Special:Contributions/173.245.54.175|173.245.54.175]] 05:35, 30 July 2014 (UTC)

That reminds me on Neil Stephensons - The Diamond Age: or A Young Lady's Illustrated Primer... Very nerdy! {{unsigned ip|108.162.254.21}}

Another very common usage of headcanon is when you REMOVE something from your headcanon - that is, pretend that it never happened, despite it being canon. Often it's case of not-really-good sequels. Or later edits: see {{w|Han shot first}}. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 10:35, 30 July 2014 (UTC)
:I thought that headcanon was everything fans imagined, not just what contradicts canon. --[[Special:Contributions/141.101.105.204|141.101.105.204]] 16:32, 30 July 2014 (UTC)

Anyone note that the computer is completely undamaged (from the cannonfire at least, no telling about when it strikes the floor), despite the desk being demolished? [[User:Zowayix|Zowayix]] ([[User talk:Zowayix|talk]]) 13:14, 30 July 2014 (UTC)

Worth mentioning the alternate term "fanon", at all? (Currently third but unlinking item {{w|Fanon|Wikipedia link}}, or the more dangerous (in the [[214|Comic 214]] sense) [http://tvtropes.org/pmwiki/pmwiki.php/Main/Fanon TVTropes link]... ) [[Special:Contributions/141.101.99.7|141.101.99.7]] 13:22, 30 July 2014 (UTC)

:I'd say no, fanon is headcanon that is accepted in huge parts of the fandom. --[[Special:Contributions/141.101.105.204|141.101.105.204]] 16:32, 30 July 2014 (UTC)

New headcanon: Black Hat Guy always has a headcannon under his hat, and in this comic he is simply showing Cueball that he got a new one. [[Special:Contributions/108.162.216.73|108.162.216.73]] 14:12, 30 July 2014 (UTC)Matthew
:Not true. In other comics where he hasn't had his hat, he did not have a cannon on his head. [[Special:Contributions/108.162.237.161|108.162.237.161]] 15:40, 30 July 2014 (UTC)

Canon (in Greek: Kanon, Arabic: Qanon, Hebrew: Kaneh) means reed, or straight. Thus trustworthy. [http://en.wikipedia.org/wiki/Canon_law#Etymology] [[User:Seebert|Seebert]] ([[User talk:Seebert|talk]]) 14:38, 30 July 2014 (UTC)

Black Hat is shown to have short dark hair. That's new xkcd canon. As far as I know, he'd always been shown wearing a hat completely covering his hair until now. --[[User:Dangerkeith3000|Dangerkeith3000]] ([[User talk:Dangerkeith3000|talk]]) 15:33, 30 July 2014 (UTC)
: Not new. http://xkcd.com/377/ [[Special:Contributions/108.162.237.161|108.162.237.161]] 15:40, 30 July 2014 (UTC)
:I always assumed black hat and white hat(perhaps all the cast) were aspects of Cueball,s psyc, a jungian zoo. {{unsigned ip|173.245.54.167}}

Ra-Ra-Rasputin {{unsigned ip|108.162.237.170}}

"The title text is a pun on the homophones *canon* and *cannon*" ... uh, the whole entire COMIC is a pun on the homophones *canon* and *cannon*. [[Special:Contributions/173.245.56.149|173.245.56.149]] 18:16, 30 July 2014 (UTC)

Kudos to the author(s) of the example using Quark. One of the best-written explanations on this wiki. [[User:Jameslucas|jameslucas]] ([[User talk:Jameslucas|" "]] / [[Special:Contributions/Jameslucas|+]]) 22:42, 30 July 2014 (UTC)

''"Fans might wonder why, on a station that has "replicators" (devices that can create any food or drink out of energy on demand), anyone would patronize a bar"'' - perhaps because they might want to, you know, socialise with other people? Call me old-fashioned... --[[Special:Contributions/141.101.99.37|141.101.99.37]] 14:23, 31 July 2014 (UTC)

Anyone know if this weeks what if is different depending on region? I only ask because it mentions my small town and I am skeptical based on past comics. [[1037: Umwelt]][[Special:Contributions/173.245.56.208|173.245.56.208]] 06:25, 1 August 2014 (UTC)

Well, it doesn't mention anyplace close to me :-)
[[Special:Contributions/141.101.98.214|141.101.98.214]] 09:04, 4 August 2014 (UTC)

No one has explained why the comic is titled "New". Because Black hat says "NEW HEADCANNON:" rather than "I HAVE A NEW HEADCANNON:", I think he is speaking not English, but some programming language. Black Hat created the headcannon by saying "new Headcannon:", which is a command to instantiate an object of type Headcannon. This is similar to previous strips http://xkcd.com/353/ and http://xkcd.com/413/, which attributed supernatural creative powers to Python's "import" statement. But "new Headcannon:" isn't Python. I don't know language it is. {{unsigned ip|108.162.237.178}}

Could the "headcannnon" refer to an idea that "blows your mind"? The trajectory of the "literal" cannon ball ends where Cueball's head was, so it went from head to head, not head to desk... --[[User:Bpothier|B. P.]] ([[User talk:Bpothier|talk]]) 22:34, 28 October 2014 (UTC)

1286: Encryptic

2013-11-14T17:32:30Z

Bpothier: /* Passwords */ - added some links

{{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|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 reversably 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>
|This has only 12 possibilities to begin with (plus variant spellings, variant lists, and one replacement), but actually we know already 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|Sugarland}} is a suburb of {{w|Houston}}, {{w|Texas}}. This fits with the previous line.
|-
|<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
|
|-
|<tt>38a7c9279cadeb44</tt>
|purloined
|<tt>asdfghjk</tt>
|A reference to the Edgar Allen 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 water-3 Pokemon 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]]

1286: Encryptic

2013-11-14T17:16:49Z

Bpothier: /* Explanation */ - removed extraneous ')' from python line

{{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|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 reversably 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>{{w|Saint_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 12 apostles
|<tt>matthias</tt>
|This has only 12 possibilities to begin with (plus variant spellings, variant lists, and one replacement), but actually we know already 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|Sugarland}} is a suburb of {{w|Houston}}, {{w|Texas}}. This fits with the previous line.
|-
|<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
|
|-
|<tt>38a7c9279cadeb44</tt>
|purloined
|<tt>asdfghjk</tt>
|A reference to the Edgar Allen Poe story "{{w|The Purloined Letter}}", this represents all the keys of the home row, or the keyboard mash password, but with one missing letter.
|-
|<tt>a8ae5745a2b7af7a 9dca1d79d4dec6d5</tt>
|fav water-3 {{w|List_of_Pokémon|Pokemon}}
|<tt>Tentacool</tt>
|This is the only water-3 Pokemon 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]]

Talk:1278: Giraffes

2013-10-17T23:21:44Z

Bpothier:

Woohoo! I made an explain xkcd article. This one wasn't that confusing, nor did it require much extra information. I am still a little new to the formatting, so please let me know what I need to improve.

The hardest parts were the date format and the transcript format. I also am unsure of how formal my explanation has to be. All of the other explanations sound so formal, and it is weird to be contributing to a community with such high standards.

Perhaps a link should be provided to say this is an allusion to Jurassic park? Perhaps? Crossing of frogs with dinosaur DNA?

Any feedback would be appreciated. (This is soo cool!)

[[User:Zyxuvius|Zyxuvius]] ([[User talk:Zyxuvius|talk]]) 04:59, 16 October 2013 (UTC)

:I'd think that'd be a giraffopod, wouldn't it? *(~.^)
:Perhaps the recurring theme of giraffes could be mentioned (not as much in the comic as in the what-if).
:[[User:Kupiakos|Kupiakos]] ([[User talk:Kupiakos|talk]]) 07:23, 16 October 2013 (UTC)

:Not sure "utopical" is a good word choice. Maybe "exotic" would be better? --[[User:Bpothier|B. P.]] ([[User talk:Bpothier|talk]]) 23:21, 17 October 2013 (UTC)

Where does the joke about Pi come in? I don't think it's in there. I think the "joke" is just that giraffes would look amazing with dinosaur tails. --[[User:Grimertop90|Grimertop90]] ([[User talk:Grimertop90|talk]]) 15:17, 16 October 2013 (UTC)

1278: Giraffes

2013-10-17T23:19:50Z

Bpothier: /* Explanation */ added monad wiki link

{{comic
| number = 1278
| date = October 16, 2013
| title = Giraffes
| image = giraffes.png
| titletext = If you fund my Kickstarter...
}}

==Explanation==
{{w|Genetic engineering}} is the scientific approach towards altering and modifying the {{w|genome}} of organisms. In the process, DNA material is extracted from a source organism and then inserted into the genome of a host organism. It is thus possible to create {{w|Hybrid (biology)|hybrids}} between species that would not crossbreed naturally. The technique is also applied in order to expedite the sometimes lengthy process of {{w|selective breeding}}.

The comic suggests the creation of genetically modified {{w|Giraffe|giraffes}}. Following the [[:Category:Dinosaurs|recurring theme]] in the comics that dinosaurs and dinosaur-like traits make life more interesting, [[Randall]] expresses his desire to see genetic engineers insert DNA from extinct {{w|Sauropoda|sauropods}} into the giraffe's genome, resulting in giraffes with very large and thick tails.

The idea of extracting and reproducing DNA material of dinosaurs appears most prominently in the 1993 motion picture ''{{w|Jurassic Park (film)|Jurassic Park}}''. The concept is regarded by scientists as rather implausible because DNA disintegrates soon after the death of the organism and would not be preserved in fossils.

Furthermore, the science of genetic engineering is not yet able to accomplish major alterations in complex genomes. While mice and other small vertebrates have successfully been modified for research purposes, the daily use of genetic engineering is limited to plants and {{w|Unicellular_organism|monads}}. The difficulty also increases when the species crossed are only distantly related to each other. The idea of adding dinosaur tails to giraffes can therefore be considered as fairly utopical.

In general, genetic engineering is a highly controversial topic with regards to the responsibility of science. While some praise the scientific progress and welcome the possibilities it brings, others fear that genetic science might enable man to alter the ways of nature and to presume the role of an almighty creator. The creation of hybrid animals (so called ''{{w|Chimera (genetics)|Chimeras}}'') is often regarded as the ultimate {{w|hubris}} and the climax of moral decay. Some countries have therefore installed strong legal restrictions for the modification of genetic material extracted from humans and animals.

The title text refers to {{w|Kickstarter}}, a funding platform for creative projects. Any person who wants to start a creative project, but lacks the resources to do so, can create a Kickstarter campaign where donors can contribute donations. Usually, the owner of the Kickstarter promises exclusive benefits to donors of certain tiers. For example, the title text could well be finished to say ''If you fund my Kickstarter with a donation of $20 or more, I will give you exclusive access to my weekly blog on the development stages of the giraffosaurus. If you donate $100 or more, you can receive a life-sized cardboard cut-out of the giraffosaurus. Donations of $10,000 or more will earn your name in a raffle for ownership of the first three giraffosaurus.''

While dinosaurs are a recurring trope since the beginning of xkcd, giraffes have been featured in some of the more recent [http://what-if.xkcd.com what-if] articles as a measurement of height.

Interestingly enough, there seems to have been a species of sauropod dinosaur that bore a certain likeness to the modern giraffe and has therefore been christened ''{{w|Giraffatitan}}''.

==Transcript==
:My Hobby:
:[Silhouette of a giraffe with a sauropod's tail.]
:Convincing genetic engineers that giraffes would look better if they had sauropod tails

{{comic discussion}}
[[Category:My Hobby]]
[[Category:Dinosaurs]]
[[Category:Biology]]

1276: Angular Size

2013-10-17T22:58:44Z

Bpothier: Clarified the "celestial sphere" title text explanation (I hope)

{{comic
| number = 1276
| date = October 11, 2013
| title = Angular Size
| image = angular size.png
| titletext = If the celestial sphere were mapped to the Earth's surface, astronomy would get a LOT easier; you'd just need a magnifying glass.
}}

==Explanation==
{{incomplete}}
This comic is a comparison of the {{w|angular diameter|angular diameters}} (or apparent diameter) of various celestial objects at the surface of the earth relative to a vertex at the center of the Earth as diagrammed in the opening panel. The objects' scales are compared to actual objects on earth. Each size given is for the object at its closest approach to earth.

London's {{w|M25 motorway}} is around 60 km (35 miles) across, a {{w|soccer field}} is about 100 meters long, a {{w|Table tennis table|ping pong table}} is 274 centimeters long, a {{w|laptop}} is about 35 centimeters across, the {{w|tilde}} symbol on a keyboard is about 5 millimeters long, and a cell of ''{{w|Escherichia coli|E. coli}}'' is about 2 microns long.

A simple {{w|Intercept theorem|formula}} can be used to find the size on earth of a celestial object when the size of and distance to the object is known. This is done by taking the radius of the earth, multiplying by the diameter of the object, and dividing by the distance to the object from the center of the earth.

The space objects referenced in the panels are:

* The {{w|Sun}} and the {{w|Moon}}, and also the open cluster {{w|Messier 25}}, have approximately the same size (around 0.5 degrees of arc) when seen from the Earth.

* {{w|Mercury (planet)|Mercury}}, {{w|Venus}}, {{w|Mars}}, {{w|Jupiter}}, {{w|Saturn}}, {{w|Uranus}}, and {{w|Neptune}} are the other planets of the {{w|Solar System}}.

* {{w|Io (moon)|Io}}, {{w|Europa (moon)|Europa}}, {{w|Ganymede (moon)|Ganymede}}, and {{w|Callisto (moon)|Callisto}} are the main moons of Jupiter; {{w|Titan (moon)|Titan}} is the largest moon of Saturn; and {{w|Triton (moon)|Triton}} is the largest moon of Neptune. {{w|Ceres (dwarf planet)|Ceres}} and {{w|Pluto}} are {{w|dwarf planet}}s.

* {{w|Phobos (moon)|Phobos}} and {{w|Deimos (moon)|Deimos}} are the moons of Mars. {{w|Eris (dwarf planet)|Eris}} is another dwarf planet. {{w|R Doradus}} and {{w|Betelgeuse}} are giant stars, respectively around 180 and 640 light-years away. R Doradus is the star with the largest apparent diameter (other than the sun, of course).

* {{w|4942 Munroe}} is an asteroid [http://blog.xkcd.com/2013/09/30/asteroid-4942-munroe/ named] after xkcd author [[Randall]] Munroe. {{w|Proxima Centauri}}, {{W|Alpha Centauri|Alpha Centauri AB}}, {{w|Barnard's star}} and {{w|Sirius}} are nearby stars (all within 10 light-years from the Sun).

* {{w|HD 189733 b}}, {{w|Gliese 581 b}}, {{w|Gliese 667 Cc}}, {{w|82 G. Eridani#Planetary_system|HD 20794 c}}, {{w|Tau Ceti#Planets|Tau Ceti c}}, and {{w|KOI-1686.01}} are {{w|extrasolar planet}}s; the parenthetical names are references to the comic [[1253: Exoplanet Names]]. However, some of the planets' parenthetical names do not match the table in the previous comic. For example, HD 20794 c is called "Legoland" rather than "Moonchild" in [[1253: Exoplanet Names]]. The {{w|black hole}} at the center of our Galaxy is {{w|Sagittarius A*}}, a massive object containing a mass more than 4 million times of our Sun.

* {{w|Voyager 1}} and {{w|Voyager 2|2}} are space probes launched in 1977, and currently around 125 and 100 {{w|astronomical unit}}s away, respectively.

The title text states that astronomy would be much easier if the celestial sphere were mapped to the earth - like a giant {{w|globe}}. Due to the distance of the stars you would need a powerful microscope to see the very tiny areas representing distant stars instead of a powerful telescope to see huge distances.

Approximate values for the mappings to the Earth sphere (based on mean Earth radius at 6,371.0 km):
{| class="wikitable sortable"
|-
! Panel
! Object
! Distance
! Diameter
! Size at Earth sphere
|-
| rowspan="4"| Panel 1
|| Sun
|| 149,600,000 km
|| 1,392,684 km
|| 59.3 km
|-
|| Moon Semi-major axis
|| 384,399 km
|| 3,476.28 km
|| 57.6 km
|-
|| Moon Perigee
|| 363,295 km
|| 3,476.28 km
|| 60.9 km
|-
|| Messier 25
|| 2,100 light-years 19.867 × 10^15 km
|| 19 light-years 179.753 × 10^12 km
|| 57.6 km
|-
| rowspan="7"| Panel 2
|| Mercury closest approach
|| 92 million km
|| 4,879.4 km
|| 0.34 km
|-
|| Venus closest approach
|| 41 million km
|| 12.103.6 km
|| 1.9 km
|-
|| Mars closest approach
|| 56 million km
|| 6,792.4 km
|| 0.77 km
|-
|| Jupiter
|| 778,547,200 km
|| 139,822 km
|| 1.14 km
|-
|| Saturn
|| 1,433,449,370 km
|| 120,536 km
|| 0.54 km
|-
|| Uranus
|| 2,876,679,082 km
|| 51,118 km
|| 0.11 km
|-
|| Neptune
|| 4,503,443,661 km
|| 49,528 km
|| 0.07 km
|-
| rowspan="8"| Panel 3
|| Io
|| 778,547,200 km
|| 3,643 km
|| 29.8 m
|-
|| Europa
|| 778,547,200 km
|| 3,122 km
|| 25.5 m
|-
|| Ganymede
|| 778,547,200 km
|| 5,262 km
|| 43.1 m
|-
|| Callisto
|| 778,547,200 km
|| 4,821 km
|| 39.5 m
|-
|| Titan
|| 1,433,449,370 km
|| 5,150 km
|| 22.9
|-
|| Triton
|| 4,503,443,661 km
|| 2,705.2 km
|| 3.8 m
|-
|| Ceres Perihelion
|| 380,995,855 km
|| 974.6 km
|| 16.3 m
|-
|| Pluto Perihelion
|| 4,437,000,000 km
|| 2,306 km
|| 3.3 m
|-
| rowspan="6"| Panel 4
|| Phobos
|| 56 million km
|| 26.8 × 22.4 × 18.4 km
|| 3.05 m
|-
|| Deimos
|| 56 million km
|| 15 × 12.2 × 10.4 km
|| 1.71 m
|-
|| Eris Perihelion
|| 5.723 × 10^9 km
|| 2326 km
|| 2.59 m
|-
|| Eris Aphelion
|| 14.602 × 10^9 km
|| 2326 km
|| 1.01 m
|-
|| Betelguse
|| 643 ± 146 light-years max. 7.464 × 10^15 km
|| 950–1,200 solar radii max. 1.671 × 10^9 km
|| 1.43 m
|-
|| R Doradus
|| 178 ± 10 light-years max. 1.778 × 10^15 km
|| 370 ± 50 solar radii max. 0.515 × 10^9 km
|| 1.85 m
|-
| rowspan="6"| Panel 5
|| 4942 Munroe
|| 2.2 AU (1.2 AU closest to earth, 179.4 × 10^6 km)
|| 9-10 km
|| 35.5 cm
|-
|| Proxima Centauri
|| 4.243 light-years 40.142 × 10^12 km
|| 0.141 solar radii 0.196 × 10^6 km
|| 3.11 cm
|-
|| Barnard's Star
|| 5.980 light-years 56.574 × 10^12 km
|| 0.196 solar radii 0.272 × 10^6 km
|| 3.06 cm
|-
|| Alpha Centauri B
|| 4.366 light-years 41.305 × 10^12 km
|| 0.865 solar radii 1.204 × 10^6 km
|| 18.6 cm
|-
|| Sirius
|| 8.6 light-years 81.362 × 10^12 km
|| 1.711 solar radii 2.382 × 10^6 km
|| 18.7 cm
|-
|| Alpha Centauri A
|| 4.366 light-years 41.305 × 10^12 km
|| 1.227 solar radii 1.708 × 10^6 km
|| 26.3 cm
|-
| rowspan="9"| Panel 6
|| HD 189733 b
|| 63 light-years 596.024 × 10^12 km
|| 1.138 Jupiter radii 159,117 km
|| 1.7 mm
|-
|| Gliese 581 g
|| 20.3 light-years 192.052 × 10^12 km
|| 1.3 to 2.0 Earth radii max. 25.484 km
|| 0.85 µm
|-
|| Gliese 581 (Parent star)
|| 20.3 light-years 192.052 × 10^12 km
|| 0.29 solar radii 403,878 km
|| 1.34 cm
|-
|| Black Hole at the center of our Galaxy
|| 25,900 light-years 245.032 × 10^15 km
|| Mass 4.31 × 10^6: 12.684 × 10^6 km
|| 0.33 mm
|-
|| Gliese 667 Cc
|| 22.7 light-years 214.757 × 10^12 km
|| 2.0 Earth radii 25.484 km
|| 0.76 µm
|-
|| Gliese 667 (Parent star)
|| 22.7 light-years 214.757 × 10^12 km
|| 0.42 solar radii 584,927 km
|| 1.74 cm
|-
|| HD 20794 c (Parent star)
|| 20 light-years 189.214 × 10^12 km
|| 0.92 solar radii 1,281,269 km
|| 4.31 cm
|-
|| Tau Ceti C (Parent star)
|| 11.905 light-years 112.629 × 10^12 km
|| 0.793 solar radii 1,104,398 km
|| 6.25 cm
|-
|| Koi-1686.01 (Parent star)
|| 1033.8 light-years 9.780 × 10^15 km
|| 0.52 solar radii 724,195 km
|| 0.47 mm
|-
| Panel 7
|| Voyager probes
|| (Voyager 1 at 126.10 AU) 1.886×10^10 km
|| 20 meters (with antennas)
|| 6.76 µm
|}

==Transcript==
{{incomplete transcript}}

{{comic discussion}}
[[Category:Math]]
[[Category:Astronomy]]

1270: Functional

2013-10-02T00:37:48Z

Bpothier: /* Explanation */ - added some clarifications on paradigms and expanded programming examples, hopefully making things less confusing...

{{comic
| number = 1270
| date = September 26, 2013
| title = Functional
| image = functional.png
| titletext = Functional programming combines the flexibility and power of abstract mathematics with the intuitive clarity of abstract mathematics.
}}

==Explanation==
{{incomplete|1270: Functional}}


[[White Hat]] questions [[Cueball]]'s faith in {{w|functional programming}}. [[Cueball]] responds saying, "Tail recursion is its own reward."

Functional programming is a famous paradigm(or style) in modern programming that favors functions that can be evaluated like mathematical function, i.e. the value returned only depends on the input given. Also, unlike {{w|Procedural programming|procedures}}, they always return a value, like {{w|Sine|sine(x)}} returns 1 when x is 90°. Furthermore, the function even can call itself, starting a loop. This is called {{w|Recursion (computer science)|recursion}}, each call does allocate its own memory (for example by using, but not limited to, a {{w|Call stack|stack}}), and works independently to the other calls.

The main difference between functional programming and {{w|imperative programming}}(or {{w|Procedural programming}}) is that in imperative programming, the functions have a {{w|control flow}} and may have local variables. In order to {{w|Iteration|iterate}}, they usually use {{w|Loop (programming)|loops}}. This means that an "imperative function" may return a different result, given the same input due to changes in some local or global variable, whereas a "functional function" will ALWAYS return the same result for a given input.

For example, the {{w|factorial}} function (e.g. "factorial(5) = 5 x 4 x 3 x 2 x 1") can be coded imperatively as:

factorial(n):
prod = 1
while n > 0:
prod = prod * n
n = n - 1
end
return prod

An imperative, recursive (but not tail-recursive) implementation can look like this:

factorial(n)
{
if n > 0
{
return n * factorial(n-1)
}
return 1
}

In this situation, the recursion stops when the argument (n) is not greater than zero. Without the conditional definition, it would be an infinite loop. The {{w|Tail recursion}} is a special case of recursion whose very '''last''' operation is to invoke the function itself or return a definite value.

This (functional) example is tail recursive inside the helper function:


factorial(n) = factorial_helper(n, 1)

factorial_helper(n, prod) =
if n > 0 then
factorial_helper(n - 1, prod * n)
else
prod

e.g.
factorial(5) = factorial_helper(5, 1)
factorial_helper(5,1) = factorial_helper(5-1, 1*5)
factorial_helper(4,5) = factorial_helper(4-1, 5*4)
factorial_helper(3,20) = factorial_helper(3-1, 20*3)
factorial_helper(2,60) = factorial_helper(2-1, 60*2)
factorial_helper(1,120) = factorial_helper(1-1, 120*1)
factorial_helper(0,120) = 120

In functional programming, tail recursion is detected by the compiler or interpreter and can be executed as efficiently as loops in imperative programming languages. This makes tail recursion an essential programming technique in functional programming.

Cueball is making a play on words where "Tail recursion is its own reward" is used both in the "it is worth doing on elegance and intellectually satisfying grounds alone" sense and in the sense that "the 'tail call' of a function is its final step, and is the final step (and hence the result/reward) for all levels of a tail-recursive function".

The title text says that to {{w|Abstract mathematics|abstract mathematicians}} functional programming is both powerful and flexible, as well as intuitive and clear since it comes very close to the way mathematicians usually describe functions. The humorous contrast is that, to non-mathematicians, functional programming can be exactly the opposite (thus being non-intuitive and unclear as abstract mathematics appears to them). And it is also a reference to a common saying about the imperative programming language, 'C': "C combines the flexibility and power of {{w|assembly language}} with the user-friendliness of assembly language".

==Transcript==
:[White Hat stands behind Cueball, who is sitting at a computer]
:White Hat: Why do you like functional programming so much? What does it actually ''get'' you?
:Cueball: Tail recursion is its own reward.

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

Talk:1266: Halting Problem

2013-09-20T23:52:59Z

Bpothier: /* Missing the obvious? */ new section

I wrote an explanation for the body of the comics, but I believe there are aspects of the title I'm still missing, so I left the incomplete tag in place. [[User:Shachar|Shachar]] ([[User talk:Shachar|talk]]) 07:52, 18 September 2013 (UTC)

Isn't google already running applications designed to continue running even if some of nodes they run on have a fatal hardware failure? Also, even if the claim would be true in "practical" sense, it would not solve the problem, because as you said, the stopping would be because of reasons external to the actual program. In other words, program running on turing machine will never stop by hardware failure, because turing machine BY DEFINITION doesn't have any. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 08:57, 18 September 2013 (UTC)
:Remembered this is wiki and added it to the actual explanation :-) -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:10, 18 September 2013 (UTC)
:Several systems are running with redundant nodes. They will not run forever. They are in for example extremely unlikely to outlive the sun. [[Special:Contributions/85.19.71.131|85.19.71.131]] 11:29, 18 September 2013 (UTC)
::System with ability to replace nodes can be deployed on nodes physically as distant as needed. Application which is currently starting on a multi-node system on earth can be later expanded to system with nodes in different star system. Although unless the nodes have FTL connection it would have inpractically large lag ... -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:39, 20 September 2013 (UTC)

"For all practical purposes, this is the correct solution"
:No, it's not. A very practical purpose would be "have my OS kill processes that won't stop". Other one would be "reject installing apps that contain algorithms that don't halt". If the OS assumes "every app will eventually halt" it would kill every process and reject every app. [[User:Osias|Osias]] ([[User talk:Osias|talk]]) 12:15, 18 September 2013 (UTC)
::Changing the paragraph to say "a physical perspective" instead of "all practical purposes" was a good solution. [[User:Osias|Osias]] ([[User talk:Osias|talk]]) 14:16, 18 September 2013 (UTC)
::It would, in fact, kill/reject none since it would find no nonhalters.[[Special:Contributions/178.0.89.106|178.0.89.106]] 20:51, 18 September 2013 (UTC)

Google "halting problem" and do a little reeding so you are in the same mindset as Randall. This is a famous computer science problem. You aren't talking about the same thing in comments above. ''— [[User:Tbc|tbc]] ([[User talk:Tbc|talk]]) 12:30, 18 September 2013 (UTC)''

What is the joke here? What does "big picture" mean? [[Special:Contributions/62.209.198.2|62.209.198.2]] 16:33, 18 September 2013 (UTC)
:I believe it's related to the quote " In the long run we are all dead." by John Maynard Keynes. [[User:Osias|Osias]] ([[User talk:Osias|talk]]) 18:46, 18 September 2013 (UTC)

Same kind of humor as in http://www.explainxkcd.com/wiki/index.php?title=221 [[Special:Contributions/176.67.13.14|176.67.13.14]] 18:47, 18 September 2013 (UTC)

A program with its given input can be seen, as a whole, as a specific program. Therefore the halting function need not take two inputs and is equivalent to a function that takes the two described inputs. Therefore I feel the comment about the number of inputs in the explanation can be removed. {{unsigned ip|66.69.243.27}}
:Yeah, the halting problem on the empty word/input is known to be equivalent to the general halting problem. I think that's the form used in this comic. {{unsigned ip|85.218.82.16}}

Might there be a reference here to Isaac Asimov's famous story "The Last Question"? (The titular question was: 'Can entropy be reversed?' Throughout the lifetime of the universe, the computer only said: 'THERE IS INSUFFICIENT DATA FOR A MEANINGFUL ANSWER.') [[Special:Contributions/174.239.229.68|174.239.229.68]] 04:18, 20 September 2013 (UTC)

== Missing the obvious? ==

Maybe it is just me, but I interpreted this to be the "DoesItHalt" function actually *running* "program", then when "program" completes (halts) it returns true. This would be the "big picture" solution and does not actually deal with the "details". --[[User:Bpothier|B. P.]] ([[User talk:Bpothier|talk]]) 23:52, 20 September 2013 (UTC)

1258: First

2013-08-30T22:17:07Z

Bpothier: /* Transcript */

{{comic
| number = 1258
| date = August 30, 2013
| title = First
| image = first.png
| titletext = Fortunately, exactly zero other annoying internet behaviors have developed during this time.
}}

==Explanation==

Cueball is commenting on the [http://knowyourmeme.com/memes/first urge] some people have to be the first to make a comment on any given posting (be it a blog post or a youtube video or some other commentable content), and to obnoxiously point out that they have made the first comment. This often manifests as the poster simply posting the word "First" without contributing any actual content to the discussion. Cueball appears glad that the practice seems to be slowly dying out. However, someone (Offscreen) is worried he will jinx it, only encouraging more people to do so.

The title text ironically states that no new annoying internet behaviours have emerged since the "first post" trend began which would continue to annoy users: a fact which is clearly wrong to anyone who spends a length of time on the internet[[http://en.wikipedia.org/wiki/Wikipedia:Citation_needed citation needed]].

==Transcript==

:[Cueball is typing at a computer.]
:[Cueball is sitting at a computer.]
:Cueball: After a couple of unbearable decades, the "First Post" thing seems to be dying a quiet death.
:Offscreen: Shh. You'll jinx it.

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

1181: PGP

2013-03-05T23:54:06Z

Bpothier: added timecode reference, typos

{{comic
| number = 1181
| date = March 4, 2013
| title = PGP
| image = pgp.png
| titletext = If you want to be extra safe, check that there's a big block of jumbled characters at the bottom.
}}

==Explanation==
{{w|Pretty Good Privacy|PGP}} (Pretty Good Privacy) is a program which can be used to encrypt and/or sign data, including messages sent as emails. Encrypting means encoding data in a way that requires a known key to decrypt and read; signing means that there is a code included in the data which can be used to verify both that the data is unaltered and to verify the true sender.

In the case of the email in this comic, it has only been signed; not encrypted (hence, the top of the first line of text can be seen and is legible in normal English). This is more common than encryption, as reading an encrypted message would require the recipient to already be a PGP user. In fact, the use of PGP even to sign email messages is so rare that most people have probably never seen a signed message. Because a signed email is so rare, and because it is already legible and unencrypted, [[Randall]] is making the observation that few users actually bother to use the signature to verify the authenticity of the sender using the PGP signature, and make the assumption that the fact that there IS a signature is good enough evidence that the message is authentic. He may also be implying that because PGP signatures are so rare and probably ignored by most recipients, he would not expect anyone to even bother creating a false PGP signature; therefore the mere existence of a PGP header will indicate authenticity. The title text extends the joke by suggesting you confirm there's a bunch of random characters in the footer (this is the actual key that PGP generates which can be used to verify the authenticity of the email. Again, Randall is saying that the existence of the block is itself evidence of authenticity.

A similar false assumption of security was pointed out in the movie {{w|Strange Brew}}, where while viewing security camera footage in a courtroom one character states: "It even has a time code on it and those are very difficult to fake." The simple appearance of a {{w|Timecode}} on a video leads some people to assume that the video must be genuine and untampered with.

==Transcript==
:How to use PGP to verify that an email is authentic:
:Look for this text at the top
:[In mail header, light grey.] Reply
:-----BEGIN PGP SIGNED MESSAGE-----
:[in mail message, light grey]
:HASH: SHA256
:Hey,
:First of all, thanks for taking care of

:[After mail message]
:If it's there, the email is probably fine

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Computers]]

1181: PGP

2013-03-04T22:24:59Z

Bpothier: Added context about web sites and fixed typo

{{comic
| number = 1181
| date = March 4, 2013
| title = PGP
| image = pgp.png
| titletext = If you want to be extra safe, check that there's a big block of jumbled characters at the bottom.
}}

==Explanation==
{{w|Pretty Good Privacy|PGP}} (or {{w|GNU_Privacy_Guard|GnuPG}} for the free, open source version) is a program which can be used to encrypt and sign data, including messages sent as emails. It is often used in combination with email software extensions, such as [http://www.enigmail.net/home/index.php Enigmail] (for Thunderbird). Encrypting the message would prevent anybody from reading it if they didn't have the key to decrypt. Signing the message would mean that the message can be verified as unaltered, if the reader was to check the message against the signature. People who use such a program typically only use the feature to sign the message, since encrypting it (which would give you the privacy) requires that the recipient already be a PGP user. Hence the irony here is that nobody actually verifies the "signature" either, but feel secure that the message appears to be signed.

PGP or {{w|Pretty Good Privacy}}, uses {{w|Public-key cryptography}}, which is defined in [https://tools.ietf.org/html/rfc4880 RFC4880]. The blob which makes the signature is a binary (clear sign) signature which is encoded into ASCII using {{w|ASCII armor}}.

The use of signing software for email is so rare that most people have never seen a signed message. The joke here lies within the approach of ignoring actual privacy guarantees PGP provides, therefore giving a false sense of security.

A similar thing happens on some web pages that simply state "This page is secure" or include the padlock icon in the body of the page, and then ask for your credit card information, while not actually using SSL (and showing that little padlock or an "https"). (Read an old blog/rant [http://www.troyhunt.com/2011/07/padlock-icon-must-die.html about the padlock icon and security]).

This irresponsible approach to security is unfortunately quite common with users and even more so for computer security related topics. When confronted with something strange (like the blob at the bottom) most people simply believe it: If it says it's secure it really has to be - even if it actually isn't.

BTW: You can annoy pretty much any security geek out there with such ignoring behaviour.

==Transcript==
:How to use PGP to verify that an email is authentic:
:Look for this text at the top
:[In mail header, light grey.] Reply
:-----BEGIN PGP SIGNED MESSAGE-----
:[in mail message, light grey]
:HASH: SHA256
:Hey,
:First of all, thanks for taking care of

:[After mail message]
:If it's there, the email is probably fine

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Computers]]

389: Keeping Time

2013-01-07T23:24:32Z

Bpothier: added Category:Music using HotCat

{{comic
| number = 389
| date = February 27, 2008
| title = Keeping Time
| image = keeping_time.png
| imagesize =
| titletext = You can identify them ahead-of-time -- they lead with their left foot when the music starts.
}}

==Explanation==
[http://imgs.xkcd.com/blag/xkcd_389.mp3 Listen to the music]

A member of a marching band, after spending seasons marching in time to their music for their shows, end up naturally walking with the rhythm of any music they hear around them, like at a shopping mall. Pausing the music for a split second would throw off the rhythm, causing them to fall. The line of music in the comic is a piano reduction of beguiling of "Never Gonna Give You Up" by Rick Astley, a reference to "Rickrolling", which is when a link to video is set up to appear as one thing but in reality, when clicked, plays "Never Gonna Give You Up". The alt text refers to the fact that almost all marching bands start marching with the left foot, so marching band members start to naturally starting with the left foot.

==Transcript==
My Hobby:
:Pausing in-store music for a split second and watching the ex-marching band kids stumble.
:[On a balcony overlooking a supermarket, a man presses a button on a pedestal. The in-store music, the first four bars of "Never Gonna Give You Up" by Rick Astley, pauses briefly after the third bar, and one of the store's patrons falls on her face.]
<<FWOMP>>

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:My Hobby]]
[[Category:Music]]

643: Ohm

2013-01-04T22:58:27Z

Bpothier: Added mathiness

{{comic
| number = 643
| date = September 30, 2009
| title = Ohm
| image = ohm.png
| titletext = More generally, with great power comes great dEnergy/dt
}}

==Explanation==
This comic is a play on the concepts of power as the human capacity to take action, and power as a strictly defined physical quantity, namely the amount of energy which flows from one locus to another in a unit of time. In calculus, this is expressed as dE/dt, hence the title text declaration that with great power comes great dEnergy/dt—though strictly speaking, great power EQUALS (is identical with) great dEnergy/dt.

The uncle's advice references the comic-book superhero {{w|Spiderman}}. In various versions of Spiderman's origin story, a teenage Peter Parker is brought up by his Aunt May and Uncle Ben. Uncle Ben cautions Peter that "with great power comes great responsibility". Through an incident involving a spider and some cutting-edge technology, Peter Parker acquires spider-like powers—great strength and the ability to adhere to walls and ceilings. Parker fails to use his new powers to stop a mugging; it turns out that the victim is none other than Uncle Ben, who dies from injuries sustained. This failure to save his uncle haunts Parker and drives him to use his new powers for heroic purposes. Visually, this comic looks like the dying Uncle Ben counselling his nephew to use his power responsibly.

Physical energy can exist in many different forms. In electrical physics, current flowing through a resistor generates heat. The basic units are defined such that the power (in {{w|Watt}}s) converted into heat is given by the square of the electrical current flowing (in {{w|Amperes}}) multiplied by the resistance of the component (in {{w|Ohm}}s). The unit, Ohm, is named for physicist {{w|Georg Ohm}} who determined experimentally that a given resistor would pass double the current when the electrical pressure ({{w|voltage}}) was also doubled.

This relationship is summarized by {{w|Ohm's law}}:
:Current = Voltage / Resistance (I=V/R)
:Voltage = Current x Resistance (V=IxR)
:Resistance = Voltage / Current (R=V/I)

{{w|Electric power}} is defined as:
:Power = Current x Voltage (P=IxV - {{w|Joule's laws|Joule's first law}})
:or by replacing "Voltage" with "(Current x Resistance)" (from Ohm's law):
:Power = Current x (Current x Resistance) = Current^2 x Resistance

==Transcript==
:[Ohm is holding his uncle by the shoulders.]
:Uncle: Remember: With great power comes great current squared times resistance.
:Narrator: Ohm never forgot his dying uncle's advice.

{{comic discussion}}
[[Category:Physics]]
[[Category:Math]]

191: Lojban

2013-01-04T00:18:42Z

Bpothier: added translated image link

{{comic
| number = 191
| date = December 1, 2006
| title = Lojban
| image = lojban.png
| titletext = zo'o ta jitfa .i .e'o xu do pendo mi
}}

==Explanation==
{{w|Lojban}} is an invented language specifically designed to have no ambiguous constructs at all. The authors mainly wanted to see if such a thing was possible, but it has a number of fans who believe the lack of ambiguities is a substantial benefit, making the language easier to use with fewer misunderstandings. However, anyone actually willing to learn a new language for this is someone [[Black Hat]] would rather avoid.

Clicking on the original comic brings you to [[:File:lojban translated.png|a Lojban translation of the comic]].

The title-text is also written in Lojban. It translates roughly as: "That was a joke. Really. Wanna be friends with me?"

==Transcript==
:Cueball: If you learned to speak Lojban, your communication would be completely unambiguous and logical.
:Black Hat: Yeah, but it would all be with the kind of people who learn Lojban.

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

File:lojban translated.png

2013-01-04T00:16:25Z

Bpothier: Comic 191 translated into lojban

== Summary ==
Comic 191 translated into lojban
== Licensing ==
{{XKCD file}}

191

2013-01-04T00:12:14Z

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#REDIRECT [[191: Lojban]]

Lojban

2013-01-04T00:11:59Z

Bpothier: Redirected page to 191: Lojban

#REDIRECT [[191: Lojban]]

246

2013-01-04T00:10:32Z

Bpothier: Redirected page to 246: Labyrinth Puzzle

#REDIRECT [[246: Labyrinth Puzzle]]

Labyrinth Puzzle

2013-01-04T00:09:15Z

Bpothier: Redirected page to 246: Labyrinth Puzzle

#REDIRECT [[246: Labyrinth Puzzle]]

246: Labyrinth Puzzle

2013-01-04T00:08:49Z

Bpothier: typos

{{comic
| number = 246
| date = April 9, 2007
| title = Labyrinth Puzzle
| image = labyrinth puzzle.png
| titletext = And the whole setup is just a trap to capture escaping logicians. None of the doors actually lead out
}}

==Explanation==
This comic alludes to a famous {{w|Knights and Knaves}}-type logic puzzle, in which there are ''two'' doors and ''two'' guards. One guard always lies, and the other always tells the truth. One of the doors leads to freedom, and you can only ask one guard one question. The solution to this riddle involves a very tricky question indeed, and one would in the xkcd-version risk a stabbing from the third guard. If you want to give the original puzzle a try for yourself, don't read the spoiling next paragraph.

Solution: Ask one guard (it doesn't matter which one) which door the other guard would say leads out. The door indicated doesn't lead out.

==Transcript==
:Black Hat: And here we have the labyrinth guards. One always lies, one always tells the truth, and one stabs people who ask tricky questions.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Logic]]

246: Labyrinth Puzzle

2013-01-04T00:06:10Z

Bpothier: Bpothier moved page 246: Labryinth Puzzle to 246: Labyrinth Puzzle: typo

{{comic
| number = 246
| date = April 9, 2007
| title = Labryinth Puzzle
| image = labyrinth puzzle.png
| titletext = And the whole setup is just a trap to capture escaping logicians. None of the doors actually lead out
}}

==Explanation==
This comic alludes to a famous {{w|Knights and Knaves}}-type logic puzzle, in which there are ''two'' doors and ''two'' guards. One guard always lies, and the other always tells the truth. One of the doors leads to freedom, and you can only ask one guard one question. The solution to this riddle involves a very tricky question indeed, and one would in the xkcd-version risk a stabbing from the third guard. If you want to give the original puzzle a try for yourself, don't read the spoiling next paragraph.

Solution: Ask one guard (it doesn't matter which one) which door the other guard would say leads out. The door indicated doesn't lead out.

==Transcript==
:Black Hat: And here we have the labrinth guards. One always lies, one always tells the truth, and one stabs people who ask tricky questions.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Logic]]

246

2013-01-04T00:04:59Z

Bpothier: Bpothier moved page 246 to 246: Labryinth Puzzle

#REDIRECT [[246: Labryinth Puzzle]]

246: Labyrinth Puzzle

2013-01-04T00:04:58Z

Bpothier: Bpothier moved page 246 to 246: Labryinth Puzzle

253

2013-01-04T00:03:23Z

Bpothier: Redirected page to 253: Highway Engineer Pranks

#REDIRECT [[253: Highway Engineer Pranks]]

Highway Engineer Pranks

2013-01-04T00:03:08Z

Bpothier: Redirected page to 253: Highway Engineer Pranks

#REDIRECT [[253: Highway Engineer Pranks]]

534: Genetic Algorithms

2013-01-04T00:02:26Z

Bpothier: added Category:Comics with color using HotCat

{{comic
| number = 534
| date = January 23, 2009
| title = Genetic Algorithms
| image = genetic_algorithms.png
| titletext = Just make sure you don't have it maximize instead of minimize.
}}

==Explanation==
Cueball is seen here defining a program (possibly in python). The title is a reference to the type of program Cueball is writing, a Genetic Algorithm.

In the computer science field of artificial intelligence, a genetic algorithm is a search heuristic that mimics the process of natural evolution. This heuristic is routinely used to generate useful solutions to optimization and search problems. Genetic algorithms belong to the larger class of evolutionary algorithms, which generate solutions to optimization problems using techniques inspired by natural evolution, such as inheritance, mutation, selection, and crossover.

The line indicated by an arrow is a reference to the Terminator series, in which the main antagonist is an artificial intelligence known as Skynet.

The line about water crossing is a possible reference to the old computer game Oregon Trail, in which crossing water was hazardous.

==Transcript==
:[Code displayed, presumably from an IDE]
:def getSolutionCosts(navigationCode):
::fuelStopCost = 15
::extraComputationCost = 8
:[There is a giant arrow pointing to the next line]
::thisAlgorithmBecomingSkynetCost = 999999999
::waterCrossingCost = 45
:Narration: Genetic algorithms tip: *Always* include this in your fitness function.

{{comic discussion}}
[[Category:Programming]]
[[Category:Comics with color]]

463

2013-01-04T00:01:51Z

Bpothier: Redirected page to 463: Voting Machines

#REDIRECT [[463: Voting Machines]]

Voting Machines

2013-01-04T00:01:28Z

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#REDIRECT [[463: Voting Machines]]

477

2013-01-03T23:59:25Z

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Typewriter

2013-01-03T23:59:05Z

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501

2013-01-03T23:56:47Z

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Faust 2.0

2013-01-03T23:56:28Z

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529

2013-01-03T23:56:03Z

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Sledding Discussion

2013-01-03T23:55:46Z

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534

2013-01-03T23:50:28Z

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Genetic Algorithms

2013-01-03T23:49:57Z

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598

2013-01-03T23:49:00Z

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Porn

2013-01-03T23:48:45Z

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658

2013-01-03T23:43:03Z

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Orbitals

2013-01-03T23:42:45Z

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679

2013-01-03T23:40:42Z

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Christmas Plans

2013-01-03T23:40:20Z

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750

2013-01-03T23:28:32Z

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Book Burning

2013-01-03T23:28:18Z

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