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	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=1002:_Game_AIs&amp;diff=100785</id>
		<title>1002: Game AIs</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=1002:_Game_AIs&amp;diff=100785"/>
				<updated>2015-09-02T04:40:06Z</updated>
		
		<summary type="html">&lt;p&gt;199.27.133.104: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 1002&lt;br /&gt;
| date      = January 11, 2012&lt;br /&gt;
| title     = Game AIs&lt;br /&gt;
| image     = game_ais.png&lt;br /&gt;
| titletext = The top computer champion at Seven Minutes in Heaven is a Honda-built Realdoll, but to date it has been unable to outperform the human Seven Minutes in Heaven champion, Ken Jennings.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
To understand the comic, you have to understand what the games are, so let's go (but first, the years in parenthesis in the comic are the year that the game was mastered by a computer):&lt;br /&gt;
&lt;br /&gt;
===Solved===&lt;br /&gt;
&lt;br /&gt;
: These games are considered &amp;quot;solved&amp;quot;, meaning the ideal maneuver for each game state (Tic-Tac-Toe, Connect Four) or each of the limited starting positions (Checkers) has already been calculated. Computers aren't so much playing as they are recalculating the list of ideal maneuvers. The same could be said for the computer's human opponent, just at a slower pace.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Tic-tac-toe}}''' or '''Noughts and Crosses''' in most of the rest of the British Commonwealth countries is a pencil-and-paper game for two players, X and O, who take turns marking the spaces in a 3×3 grid. This game nearly always ends in a tie, regardless of whether humans or computers play it, because the amount of positions is minimal.  &lt;br /&gt;
&lt;br /&gt;
*'''{{w|Nim}}''' is a mathematical game of strategy in which two players take turns removing objects from distinct heaps. On each turn, a player must remove at least one object, and may remove any number of objects provided they all come from the same heap.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Ghost (game)|Ghost}}''' is a spoken word game in which players take turns adding letters to a growing word fragment. The loser is the first person who completes a valid word or who creates a fragment that cannot be the start of a word.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Connect Four}}''' (or '''Captain's Mistress''', '''Four Up''', '''Plot Four''', '''Find Four''', '''Fourplay''', '''Four in a Row''', '''Four in a Line''') is a two-player game in which the players first choose a color and then take turns dropping their colored discs from the top into a seven-column, six-row vertically-suspended grid.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Gomoku}}''' (or '''Gobang''', '''Five in a Row''') is an abstract strategy board game. It is traditionally played with go pieces (black and white stones) on a go board (19x19 intersections); however, because once placed, pieces are not moved or removed from the board, gomoku may also be played as a paper and pencil game. This game is known in several countries under different names.&lt;br /&gt;
:Black plays first, and players alternate in placing a stone of their color on an empty intersection. The winner is the first player to get an unbroken row of five stones horizontally, vertically, or diagonally.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Draughts|Checkers}}''' (in the United States, or '''draughts''' in the United Kingdom) is a group of strategy board games for two players which involve diagonal moves of uniform game pieces and mandatory captures by jumping over opponent pieces.&lt;br /&gt;
&lt;br /&gt;
===Computers Beat Humans===&lt;br /&gt;
&lt;br /&gt;
:The below games cannot be &amp;quot;solved&amp;quot; due to the factors of random numbers, a near-infinite{{Citation needed}} number of starting positions, or the existence of multiple &amp;quot;ideal&amp;quot; maneuvers for each position. That said, a computer's faster reaction time, higher degree of consistency in making the right decision, and reduced risk of user error make the computer objectively better than the human opponent in nearly all situations.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Scrabble}}''' is a word game in which two to four players score points by forming words from individual lettered tiles on a gameboard marked with a 15-by-15 grid.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Counter-Strike|CounterStrike}}''' most likely refers to the popular multiplayer shooter video game about terrorists and counter-terrorists. Counter-Strike is notorious for the large variety of cheating tools that have been made for it; a computer would have essentially perfect accuracy and reflexes, essentially making it the {{w|aimbot}} from hell. It is theoretically possible for a skilled player to beat an AI, but it would be ''extremely'' difficult to do so.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Beer pong}}''' (or '''Beirut''') is a drinking game in which players throw a ping pong ball across a table with the intent of landing the ball in a cup of beer on the other end.&lt;br /&gt;
:[http://hacknmod.com/hack/beer-pong-robot-precision-air-pressure/ Here's the video] of the University of Illinois robot mentioned in the comic.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Reversi}}''' (marketed by Pressman under the trade name '''Othello''') is a board game involving abstract strategy and played by two players on a board with 8 rows and 8 columns and a set of distinct pieces for each side. Pieces typically are disks with a light and a dark face, each face belonging to one player. The player's goal is to have a majority of their colored pieces showing at the end of the game, turning over as many of their opponent's pieces as possible.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Chess}}''' is a two-player board game played on a chessboard, a square-checkered board with 64 squares arranged in an eight-by-eight grid. Each player begins the game with sixteen pieces: one king, one queen, two rooks, two knights, two bishops, and eight pawns, each of these types of pieces moving differently.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Jeopardy!}}''' is an American quiz show featuring trivia in history, literature, the arts, pop culture, science, sports, geography, wordplay, and more. The show has a unique answer-and-question format in which contestants are presented with clues in the form of answers, and must phrase their responses in question form.&lt;br /&gt;
:Ken Jennings, mentioned in the title text, is a famous Jeopardy champion who was beaten by {{w|Watson (computer)|Watson}}, an IBM computer.&lt;br /&gt;
&lt;br /&gt;
===Humans Beat Computers===&lt;br /&gt;
&lt;br /&gt;
:The below games are incredibly difficult to &amp;quot;solve&amp;quot; due to the near-infinite number of possible positions. Computers built in the early 21st century would take years to calculate a single &amp;quot;ideal&amp;quot; move. Worse, the human opponent has the ability to &amp;quot;bluff&amp;quot;; that is, to make a bad move, thus baiting the computer into a trap. Complex algorithms have been devised to make moves in a reasonable timeframe, but so far they are all highly vulnerable to bluffing. As mentioned in the comic, focused research and development is working on refining these algorithms to play the games better.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|StarCraft}}''' is a military science fiction real-time strategy video game. The game revolves around three species fighting for dominance in a distant part of the Milky Way galaxy known as the Koprulu Sector: the Terrans, humans exiled from Earth skilled at adapting to any situation; the Zerg, a race of insectoid aliens in pursuit of genetic perfection, obsessed with assimilating other races; and the Protoss, a humanoid species with advanced technology and psionic abilities, attempting to preserve their civilization and strict philosophical way of living from the Zerg. While even average Starcraft players can defeat the AIs that originally shipped with the games, Starcraft has since been adopted as a standard benchmark for AI research, largely because of its excellent balance.  Thanks to that attention, computers can now challenge some expert players, and the trend does not look promising for human players.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Poker}}''' is a family of card games involving betting and individualistic play whereby the winner is determined by the ranks and combinations of their cards, some of which remain hidden until the end of the game. It is also, however, a game of deception and intimidation, the ubiquitous &amp;quot;poker face&amp;quot; being considered the most important part of the game. &lt;br /&gt;
&lt;br /&gt;
*'''{{w|Arimaa}}''' is a two-player abstract strategy board game that can be played using the same equipment as chess. Arimaa was designed to be more difficult for artificial intelligences to play than chess. Arimaa was invented by Omar Syed, an Indian American computer engineer trained in artificial intelligence. Syed was inspired by Garry Kasparov's defeat at the hands of the chess computer Deep Blue to design a new game which could be played with a standard chess set, would be difficult for computers to play well, but would have rules simple enough for his then four-year-old son Aamir to understand. On April 18, 2015, a computer won [http://arimaa.com/arimaa/challenge/|the &amp;quot;Arimaa Challenge&amp;quot;], so this comic is now out of date with respect to Arimaa; it should move above ''Starcraft'' or ''Jeopardy!''.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Go (game)|Go}}''' is an ancient board game for two players that originated in China more than 2,000 years ago. The game is noted for being rich in strategy despite its relatively simple rules. The game is played by two players who alternately place black and white stones on the vacant intersections (called &amp;quot;points&amp;quot;) of a grid of 19×19 lines (beginners often play on smaller 9×9 and 13×13 boards). The object of the game is to use one's stones to surround a larger portion of the board than the opponent.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Snakes and Ladders}}''' (or '''Chutes and Ladders''') is an ancient Indian {{w|race game}}, where the moves are decided entirely by die rolls. A number of tiles are connected by pictures of ladders and snakes (or chutes) which makes the game piece jump forward or backward, respectively. Since the game is decided by pure chance, it occupies the limbo where a computer will always be ''exactly'' as likely to win as a human (which might mean it should be located right between 'humans beat computers' and 'computers beat humans').&lt;br /&gt;
&lt;br /&gt;
===Computers cannot compete===&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Mao (card game)|Mao}}''' (or '''Mau''') is a card game of the Shedding family, in which the aim is to get rid of all of the cards in hand without breaking certain unspoken rules. The game is from a subset of the Stops family, and is similar in structure to the card game Uno.&lt;br /&gt;
:The game forbids its players from explaining the rules, and new players are often told only &amp;quot;the only rule you may be told is this one.&amp;quot; The ultimate goal of the game is to be the first player to get rid of all the cards in their hand. Computers would have a difficult time integrating into Mao either because they would know all the rules -- and thus be disqualified or simply ignored by the players -- or would need a complicated learning engine that quite simply doesn't exist.&lt;br /&gt;
&lt;br /&gt;
*'''{{w|Seven minutes in heaven|Seven Minutes in Heaven}}''' is a teenagers' party game first recorded as being played in Cincinnati in the early 1950s. Two people are selected to go into a closet or other dark enclosed space and do whatever they like for seven minutes. Sexual activities are allowed; however kissing and making out are more common.&lt;br /&gt;
:As the game is focused on human interaction, there's not a whole lot a modern computer can ''do'' in the closet. It would need some kind of robotic body in order to interact with its human partner, and emotion engines that could feel pleasure and displeasure in order to make decisions. The title text claims that {{w|Honda|Honda Motor Company}} has invented a &amp;quot;{{w|RealDoll}}&amp;quot; (sex toy shaped like a mannequin) with rudimentary Seven Minutes in Heaven capabilities, but they pale in comparison to a human's.&lt;br /&gt;
&lt;br /&gt;
And finally&lt;br /&gt;
*'''{{w|Calvin and Hobbes#Calvinball|Calvinball}}''' is a reference to the comic strip {{w|Calvin and Hobbes}} by {{w|Bill Watterson}}.&lt;br /&gt;
:Calvinball is a game played by Calvin and Hobbes as a rebellion against organized team sports; according to Hobbes, &amp;quot;No sport is less organized than Calvinball!&amp;quot; Calvinball was first introduced to the readers at the end of a 1990 storyline involving Calvin reluctantly joining recess baseball. It quickly became a staple of the comic afterwards.&lt;br /&gt;
:The only hint at the true creation of the game ironically comes from the last Calvinball strip, in which a game of football quickly devolves into a game of Calvinball. Calvin remarks that &amp;quot;sooner or later, all our games turn into Calvinball,&amp;quot; suggesting a similar scenario that directly led to the creation of the sport. Calvin and Hobbes usually play by themselves, although in one storyline Rosalyn (Calvin's baby-sitter) plays in return for Calvin doing his homework, and plays very well once she realizes that the rules are made up on the spot.&lt;br /&gt;
:The only consistent rule states that Calvinball may never be played with the same rules twice. Scoring is also arbitrary, with Hobbes at times reporting scores of &amp;quot;Q to 12&amp;quot; and &amp;quot;oogy to boogy.&amp;quot; The only recognizable sports Calvinball resembles are the ones it emulates (i.e., a cross between croquet, polo, badminton, capture the flag, and volleyball.)&lt;br /&gt;
::Long story short, the game is a manifestation of pure chaos and the human imagination, far beyond the meager capabilities of silicon and circuitry.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:Difficulty of Various Games for Computers&lt;br /&gt;
&lt;br /&gt;
:[A diagram. The left column describes various levels of skill for the most capable computers in decreasing performance against humans.  The right side lists games in each particular section, in increasing game difficulty.  There are labels denoting the hard and easy ends of the diagram.]&lt;br /&gt;
&lt;br /&gt;
:'''Easy'''&lt;br /&gt;
:{|border=&amp;quot;small&amp;quot;&lt;br /&gt;
| rowspan=&amp;quot;6&amp;quot; | Solved - Computers can play perfectly&lt;br /&gt;
| rowspan=&amp;quot;4&amp;quot; | Solved for all possible positions&lt;br /&gt;
| Tic-tac-toe&lt;br /&gt;
|-&lt;br /&gt;
| Nim&lt;br /&gt;
|-&lt;br /&gt;
| Ghost (1989)&lt;br /&gt;
|-&lt;br /&gt;
| Connect Four (1995)&lt;br /&gt;
|-&lt;br /&gt;
| rowspan=&amp;quot;2&amp;quot; | Solved for starting positions&lt;br /&gt;
| Gomoku&lt;br /&gt;
|-&lt;br /&gt;
| Checkers (2007)&lt;br /&gt;
|-&lt;br /&gt;
| rowspan=&amp;quot;6&amp;quot; colspan=&amp;quot;2&amp;quot; | Computers can beat top humans&lt;br /&gt;
| Scrabble&lt;br /&gt;
|-&lt;br /&gt;
| CounterStrike&lt;br /&gt;
|-&lt;br /&gt;
| Beer Pong (UIUC robot)&lt;br /&gt;
|-&lt;br /&gt;
| Reversi&lt;br /&gt;
|-&lt;br /&gt;
| Chess &lt;br /&gt;
* February 10, 1996 - First win by computer against top human&lt;br /&gt;
* November 21, 2005 - Last win by human against top computer&lt;br /&gt;
|-&lt;br /&gt;
| Jeopardy (but just barely)&lt;br /&gt;
|-&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; rowspan=&amp;quot;4&amp;quot; | Computers still lose to top humans&lt;br /&gt;
(but focused R&amp;amp;D could change this)&lt;br /&gt;
| StarCraft (but just barely)&lt;br /&gt;
|-&lt;br /&gt;
| Poker&lt;br /&gt;
|-&lt;br /&gt;
| Arimaa&lt;br /&gt;
|-&lt;br /&gt;
| Go&lt;br /&gt;
|-&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; rowspan=&amp;quot;1&amp;quot; | &lt;br /&gt;
| Snakes and Ladders&lt;br /&gt;
|-&lt;br /&gt;
| colspan=&amp;quot;2&amp;quot; rowspan=&amp;quot;4&amp;quot; | Computers may ''never'' outplay humans&lt;br /&gt;
|-&lt;br /&gt;
| Mao&lt;br /&gt;
|-&lt;br /&gt;
| Seven Minutes in Heaven&lt;br /&gt;
|-&lt;br /&gt;
| Calvinball&lt;br /&gt;
|-&lt;br /&gt;
|}&lt;br /&gt;
:'''Hard'''&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Charts]]&lt;br /&gt;
[[Category:Video games]]&lt;br /&gt;
[[Category:Chess]]&lt;br /&gt;
[[Category:Calvin and Hobbes]]&lt;/div&gt;</summary>
		<author><name>199.27.133.104</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=592:_Drama&amp;diff=100783</id>
		<title>592: Drama</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=592:_Drama&amp;diff=100783"/>
				<updated>2015-09-02T03:41:04Z</updated>
		
		<summary type="html">&lt;p&gt;199.27.133.104: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 592&lt;br /&gt;
| date      = June 3, 2009&lt;br /&gt;
| title     = Drama&lt;br /&gt;
| image     = drama.png&lt;br /&gt;
| titletext = This happens in geek circles every so often. The &amp;quot;Hey, this is just a system I can figure out easily!&amp;quot; is also a problem among engineers first diving into the stock market.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
[[Megan]] and two [[Cueball]] like guys discuss how irrational society's interactions about sex are. They decide to throw out all these silly societal rules to end drama forever and spread this philosophy to everyone they know, which immediately leads to a huge increase in drama as shown in the chart.&lt;br /&gt;
&lt;br /&gt;
As one of the Cueballs in the comic states, people are indeed complicated and—crucially—what seems intuitive and rational to one person might seem completely irrational to someone else; so throwing out all the rules one person thinks make no sense isn't going to mean the world suddenly makes sense for everyone else. Instead, everyone who understands the old rules, whether they like them or not, will suddenly find themselves in a completely alien world to which they have no idea how to relate.&lt;br /&gt;
&lt;br /&gt;
Furthermore, any one person's sense of what seems rational is based on {{w|Complete information|incomplete information}}. The three people are trying to change all the sex rules—like the engineers referenced in the title text who think they can &amp;quot;solve&amp;quot; the stock market—can't even begin to conceive of all the chaotic factors affecting the system they're trying to fix, so they have no way of knowing which rules are truly rational and which aren't. (See the title text in comic form in [[1570: Engineer Syllogism]].)&lt;br /&gt;
&lt;br /&gt;
Geeks often fall prey to the fallacy that human interactions can be easily simplified if only a group of sufficiently qualified geeks put their minds to it as laid out in [http://www.plausiblydeniable.com/opinion/gsf.html The Geek Social Fallacies] and [http://pervocracy.blogspot.ca/2012/02/geek-social-fallacies-of-sex.html The Geek Social Fallacies of Sex].&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:[Megan and two Cueball like guys are sitting together.]&lt;br /&gt;
:Megan: Man, sex has all these crazy social rules. They just create drama.&lt;br /&gt;
:Cueball: Let's agree to change them, and make sex simple!&lt;br /&gt;
:Friend: Okay!&lt;br /&gt;
&lt;br /&gt;
:[Cueball gets up and goes out the door.]&lt;br /&gt;
:Cueball: Hooray! We've solved the problem of drama!&lt;br /&gt;
:Cueball: I'll go tell everyone!&lt;br /&gt;
&lt;br /&gt;
:[There is a graph labeled drama. Below is an axis and below that an arrow marked with time. A vertical dotted line is labeled and indicates the rule change. Drama is low, although fluctuating, before the rule change, then sharply increases afterward and continues to increase.]&lt;br /&gt;
:Drama&lt;br /&gt;
:Time&lt;br /&gt;
:Rule change&lt;br /&gt;
&lt;br /&gt;
:[Cueball closes the door and then leans against it.]&lt;br /&gt;
:Cueball: Holy shit&lt;br /&gt;
:Cueball: Guys&lt;br /&gt;
:Cueball: People are ''complicated!''&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Multiple Cueballs]]&lt;br /&gt;
[[Category:Sex]]&lt;br /&gt;
[[Category:Charts]]&lt;/div&gt;</summary>
		<author><name>199.27.133.104</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=594:_Period&amp;diff=100101</id>
		<title>594: Period</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=594:_Period&amp;diff=100101"/>
				<updated>2015-08-24T05:26:57Z</updated>
		
		<summary type="html">&lt;p&gt;199.27.133.104: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 594&lt;br /&gt;
| date      = June 8, 2009&lt;br /&gt;
| title     = Period&lt;br /&gt;
| image     = period.png&lt;br /&gt;
| titletext = 413 nanohertz, by the way.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
A {{w|Menstruation|menstrual cycle}}, also called a period, is a process marked by (among other things) a few days of abdominal cramps occurring roughly once a month.&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Period&amp;quot; is also the term in mathematics for a measure of the rate at which something happens. It measures the length of time between occurrences. For example, a full moon happens about once every 29.5 days, so its period is 29.5 days. By taking the inverse of this, we can get a different measurement, its frequency - the number of times an event happens within a given length of time. This is usually measured in hertz (pronounced the same as &amp;quot;hurts&amp;quot;), which is the number of times something happens in a second.&lt;br /&gt;
&lt;br /&gt;
The person off screen has their period every 28 days (their period has a period of 28 days, if you will). Since we can calculate the frequency based on the period, we can, indeed, calculate their &amp;quot;uterus-hertz&amp;quot; (or their &amp;quot;uterus hurts&amp;quot;).&lt;br /&gt;
&lt;br /&gt;
Yes, this has all been a setup to a terrible pun.&lt;br /&gt;
&lt;br /&gt;
413 nanohertz is the correct frequency of an event with a period of 28 days, [http://www.google.com/search?q=1%2F28+*+1%2Fdays+in+nanohertz as shown here by Google Calculator.]&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:Voice: Ugh. Stupid uterus.&lt;br /&gt;
:Cueball: Hey, your period is every 28 days, right?&lt;br /&gt;
&lt;br /&gt;
:Voice: Yes, why?&lt;br /&gt;
:Cueball: Well, period = T = 1/f.&lt;br /&gt;
:Voice: So?&lt;br /&gt;
&lt;br /&gt;
:Cueball: Using this, we can calculate something you already know.&lt;br /&gt;
:Voice: What?&lt;br /&gt;
&lt;br /&gt;
:Cueball: Your uterus-hertz.&lt;br /&gt;
:Voice: If I could get up I'd smack you.&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Physics]]&lt;br /&gt;
[[Category:Puns]]&lt;/div&gt;</summary>
		<author><name>199.27.133.104</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=575:_Tag_Combination&amp;diff=100099</id>
		<title>575: Tag Combination</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=575:_Tag_Combination&amp;diff=100099"/>
				<updated>2015-08-24T05:21:27Z</updated>
		
		<summary type="html">&lt;p&gt;199.27.133.104: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 575&lt;br /&gt;
| date      = April 29, 2009&lt;br /&gt;
| title     = Tag Combination&lt;br /&gt;
| image     = tag combination.png&lt;br /&gt;
| titletext = I love Eileen / and want you to love her / When you're around / I'm one floor above her / If you could see / just how much I adore her / Oh, that pretty red dress / I'd do anything for her / (Too ra loo ra too ra loo rye ayy)&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
&lt;br /&gt;
Song tags are a form of file {{w|metadata}} used to categorize music. Tags will typically describe the content and genre of the song, and many music organization programs and services will allow users to find all songs that contain a particular tag; so when a user searches for &amp;quot;Country breakup music,&amp;quot; they will receive a list of {{w|Country music|country}} songs about breaking up.&lt;br /&gt;
&lt;br /&gt;
In this comic, [[Cueball]] tests [[Megan]]'s claim that she can make a song name for any set of tags by coming up with a collection of mostly unrelated words: &amp;quot;{{w|lesbian}} {{w|voyeurism}} {{w|one-hit wonder}} {{w|Mashup (music)|mash-up|}}.&amp;quot; A {{w|lesbian}} is a woman who is only sexually interested in other women. {{w|Voyeurism}} is the act of watching someone else do something sexual, generally without their knowledge. A {{w|one-hit wonder}} is a band that had &amp;quot;one big hit&amp;quot; before fading from the public eye forever. A {{w|Mashup (music)|mash-up}} is when someone takes two previously unrelated songs and makes a third song that's a mix of both of them (a recent example of which would be [http://www.youtube.com/watch?v=82LCKBdjywQ this Gangam Style/Ghostbusters theme mashup]). In response, Megan almost immediately replies with two song titles that look like they would fit the tags well.&lt;br /&gt;
&lt;br /&gt;
Megan's first title, &amp;quot;I Wish That Stacy's Mom Had Jessie's Girl&amp;quot; is a ''mash-up'' of {{w|Jessie's Girl|&amp;quot;Jessie's Girl&amp;quot;}} by {{w|Rick Springfield}}, and {{w|Stacy's Mom|&amp;quot;Stacy's Mom&amp;quot;}} by {{w|Fountains of Wayne}}, which were both ''one-hit-wonders''. The second title, &amp;quot;When You Come on Eileen I Touch Myself&amp;quot; is a ''mash-up'' of {{w|Come On Eileen|&amp;quot;Come on Eileen&amp;quot;}} by {{w|Dexy's Midnight Runners}}, and {{w|I Touch Myself|&amp;quot;I Touch Myself&amp;quot;}} by {{w|Divinyls}}. Note that &amp;quot;Come on, Eileen&amp;quot; means &amp;quot;Hurry up, Eileen&amp;quot;, and that &amp;quot;to come on someone&amp;quot; means to ejaculate on someone.&lt;br /&gt;
&lt;br /&gt;
The title text is a set of potential lyrics to Megan's second title. [[Randall]] borrowed the rhyme scheme, phrasing, and subject matter from the first eight stanzas of {{w|I Touch Myself|&amp;quot;I Touch Myself&amp;quot;}} with additional subject matter inspired by {{w|Come On Eileen|&amp;quot;Come on Eileen.&amp;quot;}} The final stanza is the chorus lead-in from the latter.&lt;br /&gt;
&lt;br /&gt;
;Tags&lt;br /&gt;
*lesbian: Here &amp;quot;had&amp;quot; means &amp;quot;had sex with&amp;quot;. The two women having sex are Stacy's mom and Jessie's Girl&lt;br /&gt;
*voyeurism: &amp;quot;When You Come on Eileen I Touch Myself&amp;quot;, i.e. the voyeur looks at someone and Eileen having sex&lt;br /&gt;
*one-hit wonder: &amp;quot;Jessie's Girl&amp;quot; and &amp;quot;Stacy's Mom&amp;quot;&lt;br /&gt;
*mash-up: Both verses are mash-ups.&lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
:Cueball: So you can come up with a song title fitting any tag combination?&lt;br /&gt;
:Megan: Try me.&lt;br /&gt;
:Cueball: Lesbian voyeurism one-hit wonder mash-up.&lt;br /&gt;
:Megan: &amp;quot;I wish that Stacey's Mom had Jessie's Girl.&amp;quot;&lt;br /&gt;
&lt;br /&gt;
:Cueball: Well, that was one, but-&lt;br /&gt;
:Megan: &amp;quot;When you Come On Eileen I touch myself.&amp;quot;&lt;br /&gt;
:Cueball: Okay, wow.&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;br /&gt;
[[Category:Comics featuring Cueball]]&lt;br /&gt;
[[Category:Comics featuring Megan]]&lt;br /&gt;
[[Category:Music]]&lt;br /&gt;
[[Category:Homosexuality]]&lt;/div&gt;</summary>
		<author><name>199.27.133.104</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=Talk:1514:_PermaCal&amp;diff=90339</id>
		<title>Talk:1514: PermaCal</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=Talk:1514:_PermaCal&amp;diff=90339"/>
				<updated>2015-04-20T16:05:34Z</updated>
		
		<summary type="html">&lt;p&gt;199.27.133.104: added discussion item for title text&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;In Megan's response, the &amp;quot;h&amp;quot; in &amp;quot;19th&amp;quot; is backwards.&lt;br /&gt;
[[Special:Contributions/108.162.214.239|108.162.214.239]] 05:47, 20 April 2015 (UTC)&lt;br /&gt;
:I'm pretty sure that's a mistake since lowercase letters normally aren't used. [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 05:49, 20 April 2015 (UTC)&lt;br /&gt;
:Looks like he forgot the line on the upper left. He used the capital 19TH for Cueball. [[Special:Contributions/173.245.48.60|173.245.48.60]] 07:24, 20 April 2015 (UTC)&lt;br /&gt;
:I think it's intentional. All the H's after a T have shortened upperleft lines. Probably for nice http://www.explainxkcd.com/wiki/index.php/kerning [[User:ToaVin|ToaVin]] ([[User talk:ToaVin|talk]]) 10:12, 20 April 2015 (UTC) &lt;br /&gt;
&lt;br /&gt;
Leap seconds have nothing to do with the length of the year: corrected. [[Special:Contributions/108.162.249.162|108.162.249.162]] 07:49, 20 April 2015 (UTC)&lt;br /&gt;
&lt;br /&gt;
&amp;quot;Leap seconds normally account for the differences in the length of our 24 hour day and the time taken for the world to rotate 360 degrees on its axis&amp;quot; - this sentence mixes two unrelated concepts. First, a day is not a rotation of 360 degrees. Because the Earth also orbit the sun, the rotation from noon one day to noon the following day is a bit more than 360 degrees (360.9856 or so) (rotation measured relative to the stars) - this is why constellations appear to move throughout the year. Second, leap seconds are required because the leap day corrections of the Gregorian calendar are good, but not perfect, at matching the difference between Earth orbits (years) and Earth rotations (days). Every so often, a small correction is required. The corrections are not regular because the causes of the drift are numerous: tidal effects, orbital eccentricity, the underlying (small) flaws in the calendar, etc. I have not made any changes in the explanation. --[[Special:Contributions/141.101.104.66|141.101.104.66]] 08:41, 20 April 2015 (UTC)&lt;br /&gt;
&lt;br /&gt;
Not unrelated concept. Just not fully understood. Rotate 360 degrees is a simple way of putting things that ignores the diffrence between solar days and sidereal days. Incorrect not because someone doesn't understand the topic being discussed but because someone hasn't studied astronomy or seriously thought about how the movement of the Earth effects the length of the day--[[Special:Contributions/108.162.237.183|108.162.237.183]] 13:00, 20 April 2015 (UTC).&lt;br /&gt;
&lt;br /&gt;
While you are true on one part, that Earth doesn't take 24 hours to rotate 360 degrees (it takes around 23 hours and 56 minutes if I recall correctly), leap seconds are used to account for differences between 24 hours and a solar day. If it was used to adjust the length of the year the time of day would drift, it would also be fairly pointless as the leap days take us out by 1/4 of a day.[[Special:Contributions/108.162.250.175|108.162.250.175]] 10:41, 20 April 2015 (UTC)&lt;br /&gt;
&lt;br /&gt;
Do we know for sure that this comic was released on a Sunday - the 19th instead of the 20th? The first entry in this page is from the 20th. Of course there are some references to the 19th, but then again it is obvious that it is on the 20th that Megan asks. Anyone who can find out if this is the correct date, or just a mistake by someone who misunderstood something based on the dates in the comic? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:19, 20 April 2015 (UTC)&lt;br /&gt;
:Yes, it was released on the 19th, at about 10 PM CST. All of the recent comics have been released a few hours early though, so if you want the date set at 20, fine. [[User:Mikemk|Mikemk]] ([[User talk:Mikemk|talk]]) 15:05, 20 April 2015 (UTC)&lt;br /&gt;
:The archive claims that it was released on the 20th.--[[User:17jiangz1|17jiangz1]] ([[User talk:17jiangz1|talk]]) 15:08, 20 April 2015 (UTC)&lt;br /&gt;
Apropos a &amp;quot;permanent calendar&amp;quot;, Isaac Asimov proposed just such a calendar. http://calendars.wikia.com/wiki/World_Season_Calendar This web page unfortunately doesn't go into details, but there were several advantages. The same calendar is used for all years, your birthday is always on the same day of the week, no need to remember &amp;quot;30 days hath Sept. ...&amp;quot;, and several other advantages I can't remember right now. --[[User:RenniePet|RenniePet]] ([[User talk:RenniePet|talk]]) 12:45, 20 April 2015 (UTC)&lt;br /&gt;
&lt;br /&gt;
There is some confusion between the different types of astronomical time:  a day in mean solar time is 24 hours, with a difference of + or - up to 1 second (compared to time on an atomic clock), in apparent solar time is 24 hours + or - up to 30 seconds, and in mean sidereal time is 23 hours, 56 minutes, 4.0916 seconds (according to Wikipedia), and there is one extra sidereal day (about 366.25) in a sidereal year. [[User:The Dining Logician|The Dining Logician]] ([[User talk:The Dining Logician|talk]]) 13:55, 20 April 2015 (UTC) &lt;br /&gt;
&lt;br /&gt;
It seems like our collective favorite word just might be &amp;quot;portmanteau&amp;quot; [[User:YourLifeisaLie|The Goyim speaks]] ([[User talk:YourLifeisaLie|talk]]) 13:42, 20 April 2015 (UTC)&lt;br /&gt;
&lt;br /&gt;
The explanation seems unclear where it addresses the title text.  I'm not sure what is meant by &amp;quot;maybe 100ms every few months,&amp;quot; but it seems to miss the point of the comic.  If a leap day is added each time the previous day ends, then at millisecond resolution, a new leap-millisecond would be added every millisecond!  Hence the resulting DDOS when pushing so many NTP notifications... [[Special:Contributions/199.27.133.104|199.27.133.104]] 16:05, 20 April 2015 (UTC)&lt;/div&gt;</summary>
		<author><name>199.27.133.104</name></author>	</entry>

	<entry>
		<id>https://www.explainxkcd.com/wiki/index.php?title=1454:_Done&amp;diff=79989</id>
		<title>1454: Done</title>
		<link rel="alternate" type="text/html" href="https://www.explainxkcd.com/wiki/index.php?title=1454:_Done&amp;diff=79989"/>
				<updated>2014-12-01T06:01:02Z</updated>
		
		<summary type="html">&lt;p&gt;199.27.133.104: Transcription error: changed ellipses at end of last line to period.&lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;{{comic&lt;br /&gt;
| number    = 1454&lt;br /&gt;
| date      = December 1, 2014&lt;br /&gt;
| title     = Done&lt;br /&gt;
| image     = done.png&lt;br /&gt;
| titletext = I'm sorry, but the author of this Facebook comment clearly believes you were.&lt;br /&gt;
}}&lt;br /&gt;
&lt;br /&gt;
==Explanation==&lt;br /&gt;
The comic pokes fun at an internet meme in which users will post comments like &amp;quot;That's it. We're done. We can shut down the internet now.&amp;quot; in response to content found humorous or clever. The comic contrasts the legitimate, intimate impact the internet can have with the simple entertainment value that some people can see as its only or primary use. &lt;br /&gt;
&lt;br /&gt;
==Transcript==&lt;br /&gt;
Girl (typing): I had started to think I was asking too much, that I needed to settle. And then I found you half a world away. &lt;br /&gt;
&lt;br /&gt;
Girl (typing): I've been saving money. Six months from now, I'll be able to fly you here and support us for a while. &lt;br /&gt;
&lt;br /&gt;
Girl (typing): It's a long wait, but we'll talk every day until then. Maybe this won't work out, but I want to try. What do you think? &lt;br /&gt;
&lt;br /&gt;
Computer: '''ERROR''': Your message could not be sent. &lt;br /&gt;
&lt;br /&gt;
''[Refresh]'' &lt;br /&gt;
&lt;br /&gt;
Computer: '''ERROR''': No connection. &lt;br /&gt;
&lt;br /&gt;
Girl: ?? &lt;br /&gt;
&lt;br /&gt;
Girl: Why can't I connect? &lt;br /&gt;
&lt;br /&gt;
Ponytail: Someone saw a ridiculous video and said &amp;quot;That's it. Shut down the internet. We're done.&amp;quot; So they did. &lt;br /&gt;
&lt;br /&gt;
Girl: ... But... I wasn't done. &lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
{{comic discussion}}&lt;/div&gt;</summary>
		<author><name>199.27.133.104</name></author>	</entry>

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