explain xkcd - User contributions [en]

1377: Fish

2022-05-26T18:00:02Z

Ncpenguin: Undo revision 277222 by Donald Trump (talk)

{{comic
| number = 1377
| date = June 4, 2014
| title = Fish
| image = fish.png
| titletext = [Astronomer peers into telescope] [Jaws theme begins playing]
}}

==Explanation==
The {{w|Fermi paradox}} is the contradiction that arises between high estimates of the likelihood of {{w|extraterrestial life}} and the fact that no evidence for it has thus far been found.

[[Cueball]] and [[Megan]] are having a conversation regarding this — since new planets are found all the time around distant stars, Cueball comments that this makes it an even greater paradox. Megan suggests that perhaps our search for extraterrestrial life is like looking at a patch of ocean floor looking for a fish. The diver knows that there must be a fish somewhere, but is unable to actually find it. She then goes on to ask why the fish would be hidden — i.e. camouflaged, and what it means about the remaining fish. The suggestion is that the fish would be hidden to avoid being eaten by predators, and perhaps the reason no extraterrestrial life is sending any sign of existence back is that they fear they might be destroyed soon after they revealed their location. Maybe they have even actively tried to hide the presence of their entire planet if they obtain the technological means. This potentially refers to the [http://articles.adsabs.harvard.edu/full/gif/1983QJRAS..24..283B/0000296.000.html Deadly Probes scenario] where a space faring species has developed deadly probes that self replicate and spread through the void between the stars - homing in on radio signals and destroying young civilizations in the cradle...

The camouflaged fish could be identified by using more sophisticated technologies like infrared cameras. Looking at the Earth from space beyond {{w|Low Earth orbit}} only with the naked eye wouldn't show any hint to our {{w|ecosystem}}. This is like the actual possibility in astronomy when observing {{w|Exoplanet|exoplanets}} — the nature of those more than 1,500 known planets is unknown due to the lack of better technologies to the scientists. And there are a couple of hundred billion planets at our galaxy still camouflaged to human scientists.

The final panels take the metaphor further, suggesting that there is literally a planet sized shark swimming through space eating planets, and since the view is panning away from earth and over to the shark, the shark seems to be heading our way. It looks like Earth is the next fish, presumably because we did not reach a high enough technology level in time to recognize the danger and hide.

This also explains the title text that has the theme from the movie ''{{w|Jaws (film)|Jaws}}'' playing while astronomers look into their telescopes. This may also be a reference to the film ''{{w|Alien (film)|Alien}}'', which was pitched with the three word proposal "''Jaws'' in Space."

{{w|Stephen Hawking}} famously warns, "If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans." Chinese sci-fi author {{w|Liu Cixin}} wrote an award-winning sci-fi trilogy called the ''{{w|Remembrance of Earth’s Past}}'' trilogy, which draws on a similar idea; the title of the second book, ''{{w|The Dark Forest}}'', is a reference to the same Fermi paradox solution described in the comic. Even {{w|Carl Sagan}} called the practice of Broadcasting and Signaling presence of Life on Earth "deeply unwise and immature," and recommended that "the newest children in a strange and uncertain cosmos should listen quietly for a long time, patiently learning about the universe and comparing notes, before shouting into an unknown jungle that we do not understand."

==Transcript==
:[Cueball and Megan are walking down a hill.]
:Cueball: The Fermi paradox keeps getting worse. If planets are common, where ''is'' everybody?

:Megan: Imagine you're a scuba diver looking at the ocean floor. You know there's a fish there, but you can't see it. Why?

:Cueball: Maybe the fish looks like sand.
:Megan: Yeah...

:[Zoom out to the Earth from space.]
:Megan: ...and what would that tell you about the ecosystem?

:[Earth moves slightly out of the panel.]

:[Earth moves halfway out of the panel.]

:[Blank panel.]

:[A shark swims through space.]

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Astronomy]]
[[Category:Science]]
[[Category:Aliens]]
[[Category:Sharks]]

1395: Power Cord

2022-05-26T17:57:12Z

Ncpenguin: Undo revision 277691 by Donald Trump (talk)

{{comic
| number = 1395
| date = July 16, 2014
| title = Power Cord
| image = power_cord.png
| titletext = In this situation, gzip /dev/inside to deflate, then pipe the compressed air to /dev/input to clean your keyboard. Avert your eyes when you do.
}}

==Explanation==
In this comic, we see [[Beret Guy]] walking in from the left, as [[Cueball]] is sitting on a couch, typing on a {{w|laptop}} on his {{w|lap}}, with its {{w|power cord}} unplugged. Instead of connecting it to the {{w|wall socket}}, Beret Guy picks it up and blows air into the loose end of the cord, as if inflating a balloon — and the laptop inflates. It then floats away, making Cueball grab for it as Beret Guy casually walks away. (See an instance where Cueball inflates something in a similar unexpected way in [[1798: Box Plot]]).

It is not possible to inflate a laptop like this{{Citation needed}}, and (with [https://www.youtube.com/watch?v=ugVRY-Cv7Ng&t=401s rare exceptions]) it is not possible to inflate ''anything'' by blowing down a power cord. Beret Guy has previously demonstrated several [[:Category:Strange powers of Beret Guy|supernatural abilities]], for instance with power cords, such as in [[1293: Job Interview]].

In general, human breath should not be buoyant enough to lift much in an atmosphere of ordinary air. The only chemical difference between dry air and dry exhaled breath is the conversion of oxygen (molecular weight = 32) to carbon dioxide (MW=44), not counting substances in such low concentrations that their effect on the average molecular weight of the air (MW=29) is negligible. A change of concentration of the CO2 from [https://www.engineeringtoolbox.com/air-composition-d_212.html 0.04%] to about [https://en.wikipedia.org/wiki/Breathing#Composition 4%] is typical. This increases the average molecular weight. However, exhaled breath is also usually much more humid than air, increasing the concentration of water (MW=18) from a typical value of 1% to approximately 5%, which decreases the average molecular weight. The two changes approximately cancel each other.

{| class="wikitable" style="text-align:right;"
|- style="font-weight:bold; text-align:center;"
! style="text-align:right; font-weight:normal;" |
! MW
! style="background-color:#efefef;" | Dry air
! style="background-color:#efefef;" | Fractional MW 
! Air with 1% water
! Fractional MW 
! style="background-color:#efefef;" | Exhaled composition dry
! style="background-color:#efefef;" | Fractional MW 
! Exhaled composition with 5% water
! Fractional MW 
|-
| style="font-weight:bold;" | N2
| style="text-align:left;" | 28.01
| style="background-color:#efefef;" | 78.08%
| style="background-color:#efefef;" | 21.87
| 77.30%
| 21.65
| style="background-color:#efefef;" | 78%
| style="background-color:#efefef;" | 21.85
| 74.10%
| 20.76
|-
| style="font-weight:bold;" | O2
| style="text-align:left;" | 32.00
| style="background-color:#efefef;" | 20.95%
| style="background-color:#efefef;" | 6.70
| 20.74%
| 6.64
| style="background-color:#efefef;" | 17%
| style="background-color:#efefef;" | 5.44
| 16.15%
| 5.17
|-
| style="font-weight:bold;" | Ar
| style="text-align:left;" | 39.95
| style="background-color:#efefef;" | 0.93%
| style="background-color:#efefef;" | 0.37
| 0.92%
| 0.37
| style="background-color:#efefef;" | 1%
| style="background-color:#efefef;" | 0.40
| 0.95%
| 0.38
|-
| style="font-weight:bold;" | CO2
| style="text-align:left;" | 44.01
| style="background-color:#efefef;" | 0.04%
| style="background-color:#efefef;" | 0.02
| 0.04%
| 0.02
| style="background-color:#efefef;" | 4%
| style="background-color:#efefef;" | 1.76
| 3.80%
| 1.67
|-
| style="font-weight:bold;" | H2O
| style="text-align:left;" | 18.01
| style="background-color:#efefef;" |
| style="background-color:#efefef;" |
| 1.00%
| 0.18
| style="background-color:#efefef;" |
| style="background-color:#efefef;" |
| 5.00%
| 0.90
|-
| style="font-weight:bold;" | Total
| style="font-weight:bold; text-align:left;" |
| style="background-color:#efefef;" | 100.00%
| style="background-color:#efefef; font-weight:bold;" | 28.97
| 100.00%
| style="font-weight:bold;" | 28.86
| style="background-color:#efefef;" |
| style="background-color:#efefef; font-weight:bold;" | 29.45
| 100.00%
| style="font-weight:bold;" | 28.88
|}

Because humans are warm-blooded, human breath is slightly warmer than the surrounding air, and therefore has slightly fewer molecules per unit volume. This is also true of hot air balloons, but they operate at much higher temperatures than human breath and are therefore able to obtain a greater amount of net buoyancy. There is a standard cartoon convention that {{tvtropes|AllBalloonsHaveHelium| inflating something with breath}} nonetheless makes it lighter than air. Also, given Beret Guy's many manifestations of inexplicable phenomena, it is not too far fetched to believe his body is, in fact, expelling some form of lighter-than-air gas, similar to the character Rigel on Farscape who could "fart helium".

The title text involves some jokes on {{w|Unix}} systems. On Unix, {{w|everything is a file}}; even most of the hardware can be referenced by a (virtual) file. These virtual files usually are in /dev or another virtual filesystem like /sys or /proc. While /dev/input really exists and points to the input system (mice, keyboards, gamepads, etc.), /dev/inside doesn't. {{w|gzip}} is a common tool to compress files. The first joke is to compress the air inside the laptop (with the command <code>gzip /dev/inside</code>) in order to deflate the laptop back to normal size. It is a pun with the literal meaning of "deflate", which is also the {{w|DEFLATE}} algorithm used by gzip (compressing files is also called "deflating"). Another joke is "{{w|Pipeline (Unix)|piping}}", the act of using the output of one operation as the input to another. As the output of the gzip command would be compressed air, a ''physical'' pipe could be used to direct the air somewhere useful. The output of a command can also be redirected to a file. Since the hardware is a file, the suggestion is to direct the air to /dev/input (which, in this case, means the keyboard, but would actually be a directory on real system, which can't normally be piped into) to clean it, similar to "compressed air" dusting cans. The complete command would be <code>gzip /dev/inside | /dev/input</code>. As this might cause a spray of unpleasant detritus (compare [[237: Keyboards are Disgusting]]), the reader is advised to avert their eyes.

==Transcript==
:[Beret Guy enters to find Cueball on a chair typing on a laptop. Cueball's power cord is unplugged from the wall.]
:Cueball typing: Type type

:[Beret Guy picks up the power cord. Cueball continues typing.]
:Cueball typing: Type type

:[Beret Guy blows into the plug end of the cord. The laptop abruptly inflates and Cueball jerks back.]
:Beret Guy: '''PBBBBT'''
:Laptop: '''FOOMP'''

:[Beret Guy walks away, leaving Cueball climbing up his chair to retrieve his inflated laptop which is now floating away.]

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Beret Guy]]
[[Category:Strange powers of Beret Guy]]

1958: Self-Driving Issues

2022-05-26T17:55:41Z

Ncpenguin: Undo revision 277240 by Donald Trump (talk)

{{comic
| number = 1958
| date = February 21, 2018
| title = Self-Driving Issues
| image = self_driving_issues.png
| titletext = If most people turn into murderers all of a sudden, we'll need to push out a firmware update or something.
}}

==Explanation==

[[Cueball]] explains being worried about {{w|autonomous car|self-driving cars}}, noting that it may be possible to fool the sensory systems of the vehicles. This is a common concern with {{w|AI}}s; since they think analytically and have little to no capability for abstract thought, they can be fooled by things a human would immediately realize is deceptive.

However, Cueball quickly assumes that his argument actually doesn't hold up when comparing AI drivers to human drivers, as both rely on the same guidance framework. Human drivers follow signs and road markings, and must obey the laws of the road just as an AI must. Therefore, an attack on the road infrastructure could impact both AIs and humans. However, humans and AIs are not equally vulnerable. For example, a fake sign or a fake child could appear to a human as an obvious fake but fool an AI. A creative attacker could put up a sign with CAPTCHA-like text that would be readable by humans but not by an AI.

Cueball further wonders why, in this case, nobody tries to fool human drivers as they might try to fool an AI, but [[White Hat]] and [[Megan]] point out that most {{w|Road traffic safety|road safety systems}} benefit from humans not actively trying to maliciously sabotage them simply to cause accidents.{{Citation needed}}

The title text continues the line of reasoning, noting that if most people did suddenly become murderers, the AI might be needed to be upgraded in order to deal with the presumable increase in people trying to cause car crashes by fooling the AI - a somewhat narrowly-focused solution given that a world full of murderers would probably have many more problems than that. As Megan sees humans as a 'component' of the road safety system, it might also be suggesting a firmware update for the buggy people who have all become murderers, one that would fix their murderous ways. We are not currently at a point where we can create and apply instantaneous firmware updates for large populations; even combining all the behavioral modification tools at our disposal -- {{w|psychiatry}}, {{w|cognitive behavioral therapy}}, {{w|hypnosis}}, {{w|mind-altering drugs}}, {{w|prison}}, {{w|CRISPR}}, etc. -- is not enough to perform such a massive undertaking, as far as we know. The update might be about the car's firmware since it can used to disable the brakes and thus causing or preventing many deaths.

==Transcript==
:[Cueball is speaking while standing alone in a slim panel.]
:Cueball: I worry about self-driving car safety features.

:[In a frame-less panel it turns out that Cueball is standing between White Hat and Megan, holding his arms out towards each of them, while he continues to speak.]
:Cueball: What's to stop someone from painting fake lines on the road, or dropping a cutout of a pedestrian onto a highway, to make cars swerve and crash?

:[Zoom in on Cueball's head as he continues to contemplate the situation holding a hand to his chin, while looking in White Hat's direction. Megan replies from off-panel behind him.]
:Cueball: Except... those things would also work on human drivers. What's stopping people '''''now? '''''
:Megan (off-panel): Yeah, causing car crashes isn't hard.

:[Zoom back out to show all three of them again.]
:White Hat: I guess it's just that most people aren't murderers?
:Cueball: Oh, right. I always forget.
:Megan: An underappreciated component of our road safety system.

==Trivia==
The [[title text]] was published with a typo: "murderers" was misspelled as "muderers."

The theme of human fear and overreaction to the advent of more or less autonomous robots also features in [[1955: Robots]].

Self-driving cars is a [[:Category:Self-driving cars|recurring subject]] on xkcd.

A variation on the idea that humans are mentally "buggy" is suggested in [[258: Conspiracy Theories]], though in that case divine intervention is requested to implement the "firmware upgrade".

This comic appeared one day after the Electronic Frontier Foundation co-released a report titled [https://www.eff.org/deeplinks/2018/02/malicious-use-artificial-intelligence-forecasting-prevention-and-mitigation The Malicious Use of Artificial Intelligence: Forecasting, Prevention, and Mitigation]. The report cites subversions and mitigations of AI such as ones used in self-driving cars. However, the report tends toward overly technical means of subversion. Randall spoofs the tenor of the report through his mundane subversions and over-the-top mitigations.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Megan]]
[[Category:Self-driving cars]]
[[Category:Sabotage]]

1558: Vet

2022-05-26T17:53:09Z

Ncpenguin: Undo revision 278670 by Donald Trump (talk)

{{comic
| number = 1558
| date = July 31, 2015
| title = Vet
| image = vet.png
| titletext = It's probably for the best. Since Roombas are native to North America, it's illegal for Americans to keep them in their houses under the Migratory Bird Treaty Act.
}}

==Explanation==
{{w|Roomba}} is a brand of domestic cleaning robots manufactured by the company {{w|iRobot}}. The robots are designed to automatically vacuum floors. Although these robots are controlled by a quite simple software without any artificial intelligence, some owners tend to humanize them in the same way that others humanize their pets. There are [[:Category:Roomba|several other comics]] related to a Roomba.

[[Megan]] presents a {{w|pet carrier}} to [[Cueball]] the {{w|veterinarian}} assistant. She says that her "dog" is “crawling around eating dirt”, which sounds like certain types of behavioral problems one encounters in dogs, but is precisely what Roombas are made for. (However, the vacuum bag may need to be cleaned.) The vet then comments that it is a Roomba, to which Megan responds that the device (which has nothing to do with an animal) is a cross-breed, and agrees that there probably is “some Roomba” in it. She thus acknowledges the existence of Roombas, but still treats them as if it were an animal. It's common to talk about domestic dogs this way, but cross-breeding dogs with machines is impossible.{{Citation needed}} The vet then goes on to say, with endless patience, that a Roomba is not a pet. This is taken by Megan as if the doctor said that her Roomba-like device is a non-domesticated animal (like a monkey, a fox, or the birds referred to in the title text) that can but should not be kept in captivity. In the last panel she consequently releases the vacuum cleaner and it whirs to its 'freedom'.

The second customer, [[Hairy]], has his dog on a leash, but is also carrying a pet transporter for the dog. Most likely he has arrived with the dog in the transporter (perhaps using public transportation) but has now taken it out so it can walk for itself, making the carrier much lighter.

The {{w|Migratory Bird Treaty Act of 1918|Migratory Bird Treaty act}} from the title text contains a list of over 800 bird species that are not allowed to be captured or killed. If the Roomba were to be classified as a native American bird and were added to the list, keeping them as pets would constitute capturing and would be considered illegal. This, of course, shows how confused Megan is. She previously stated the Roomba to be a dog and now apparently believes it is a bird, even though dogs are not birds{{Citation needed}} and neither is the Roomba.{{Citation needed}}

==Transcript==
:[Megan arrives with a pet carrier, Cueball stands at a desk as a veterinarian, and Hairy is waiting behind a rope, standing next in line with a dog on a leash and a pet carrier.]
:Megan: There's something wrong with my dog. He keeps crawling around eating dirt.

:[Cueball holds the content of Megan's pet carrier, a flat disk. She is standing behind the desk with the carrier on the desk.]
:Cueball: This is a Roomba.
:Megan: Well, he's a mix.
:Megan: Probably some Roomba in there.

:[The Roomba now lies on the table next to the carrier between the two.]
:Cueball: A Roomba is not a pet.
:Megan: You're right. It's wrong to keep a beautiful creature like this in a house.

:[Megan is outside left to a tree, arms up in the air, encouraging the Roomba to drive away.]
:Megan: Go!
:Megan: Be free!
:Roomba: ''Whirrr''

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Hairy]]
[[Category:Robots]]
[[Category:Roomba]]
[[Category:Animals]]

2624: Voyager Wires

2022-05-25T22:42:33Z

Ncpenguin: Rephrasing and correcting a typo

{{comic
| number = 2624
| date = May 25, 2022
| title = Voyager Wires
| image = voyager_wires.png
| titletext = Also, they're getting increasingly worried that someone will accidentally hit the 'retract' button, and that the end of the cable thrashing around as it winds up could devastate the Earth's surface.
}}

==Explanation==
{{incomplete|Created by a WIRE CUT BECAUSE OF BUDG- are you there houston? it's me v----ger, you'll never guess what I found! Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic claims that the Voyager probes communicate with NASA though ridiculously long copper wires, when in reality they use radio waves.{{citation needed}} These wires would have to be continuously lengthened as the probes travel away from Earth. Supposedly, because of "high copper prices and budget constraints," they may not be able to afford to lengthen the wires much longer. If this occurred, they would have to either cut the wires or let them break, which would prevent any further communication with the probes. As mentioned earlier, however, they actually use radio waves, not long copper wires, so this will not actually happen.

If copper wires were dragged by the Voyager probes, 550 tons of copper would be needed per hour if the cable was 1mm² thick and it would add 1 million Ohm per hour to the cable resistance.

The resulting wire would slow down the probes by drag, but be perfect space elevators for lightweight spacecraft.
Of course, since the Earth spins, the wires would also spool around the Earth, slowing the probes down even further. Clearly, this is not a good idea.{{citation needed}}

This doesn't even factor in how the Earth, in its rotation around the sun, will drag these copper wires in a circular orbit leading the wires through the sun at least once per year. The difference between the melting point of copper and the average core temperature of the sun has not yet been established by reproducible experiment, but is believed to be incompatible with the high quality required for signal transmission.

The consequence of a cable between a craft in space and a planetary location being suddenly retracted was recently demonstrated in the first episode of the Apple TV series {{w|Foundation}}. It didn't end well for anyone.

A few days before this comic was released, NASA had [https://voyager.jpl.nasa.gov/news/details.php?article_id=124 reported] to have received corrupted position data from Voyager probe.

====Alternate Explanation====
When Randall Munroe states that Voyager 1 and 2 are cabled to the Earth by copper wires, his assertion deserves serious consideration.{{citation needed}}

The primary explanation, above, takes the position that this comic is ridiculously wrong.{{citation needed}} But the insertion of several "citation needed" links suggests that the explanation's position is weak.{{citation needed}}

The{{citation needed}} comic's{{citation needed}} author,{{citation needed}} Randall{{citation needed}} Munroe,{{citation needed}} is{{citation needed}} well{{citation needed}} attested{{citation needed}} as{{citation needed}} a{{citation needed}} competent{{citation needed}} scientist,{{citation needed}} for{{citation needed}} example{{citation needed}} see{{citation needed}} the{{citation needed}} citations{{citation needed}} in{{citation needed}} the{{citation needed}} [https://en.wikipedia.org/wiki/Randall_Munroe Wikipedia{{citation needed}} Randall{{citation needed}} Munroe{{citation needed}} page].{{citation needed}} His{{citation needed}} books,{{citation needed}} cited{{citation needed}} in{{citation needed}} that{{citation needed}} same{{citation needed}} Wikipedia{{citation needed}} article,{{citation needed}} offer{{citation needed}} well-{{citation needed}}researched{{citation needed}} easy{{citation needed}} to{{citation needed}} understand{{citation needed}} discussions{{citation needed}} of{{citation needed}} science{{citation needed}} and{{citation needed}} of{{citation needed}} everyday{{citation needed}} phenomena.{{citation needed}} Trust{{citation needed}} him.{{citation needed}}

(For completeness, see another Wikipedia article, [https://en.wikipedia.org/wiki/Disinformation Disinformation]. In its subsection ''Strategies for spreading disinformation'', strategy number 4 is "Directly Sharing Disinformation".{{citation needed}} That is mentioned here only because the top header at the xkcd web site states it is a webcomic of romance, '''sarcasm,''' math, and language.){{citation needed}}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
[There is an image of a space probe, presumably one of NASA's Voyager probes, with a long wire connecting it to a ball, presumably earth. To the left, there is a second wire, which goes offscreen. Below, there is a caption.]

Caption: "Sad news: Due to high copper prices and budget constraints, NASA may finally have to cut the wires that they've been spooling out to communicate with Voyager 1 and 2."
{{comic discussion}}

Talk:890: Etymology

2022-05-24T01:45:15Z

Ncpenguin:

It always bothered me how an independent gunslinger with no team of engineers or assistants has a faster ship than the entirety of the empire and all it's technical expertise. Where did he get his funding and kit from? '''[[User:Davidy22|{{Color|purple|David}}y²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 10:09, 9 March 2013 (UTC)

The same place as the Falcon.... gambling with people like Lando? (Also Falconry, by whatever name, was practiced in Mesopotamia and by the Bedouin in arguably at least partially desert-planet-like areas. It's quite possible that the ancestral 'Falcons' or equivalent translator-microbe-referenced creatures originated ''on'' Tatooine. A long, long time later, in a galaxy (and planet) much, much less far away (basically, here... and now) our Earth falcons are at least one branch of descendents.) Now, no doubts "Millenium" refers to the Imperial (previously Republican) standard years, but it begs the question of what the length and nature of the Tattooine 'year' is, given it's a binary-star orbitter, eh? ;) [[Special:Contributions/178.99.81.144|178.99.81.144]] 16:51, 30 April 2013 (UTC)
:I think you meant to say; "raises the question" :P [[User:The Cat Lady|-- The Cat Lady]] ([[User talk:The Cat Lady|talk]]) 10:01, 22 August 2021 (UTC)
He won the ship from Lando, that guy owned his own city. Military ships carry much more equipment and are less manoeuvrable. [[Special:Contributions/184.66.160.91|184.66.160.91]] 19:21, 16 July 2013 (UTC)
:Plus, most commercial and government ships have extra equipment for safety and reliability. If you take a car, strip everything out of it, and put a nitrous oxide injection system in it, it will be faster than any cop car. The cop car will be able to withstand an accident much better (they are often rated for 70-mph rear-end collisions) and will typically start every time the key is turned.
: Oh, and I think Lando did not yet run Cloud City when Han won the Falcon from him. I recall Han being surprised to find out Lando had won Cloud City, in The Empire Strikes Back. [[User:Tryc|Tryc]] ([[User talk:Tryc|talk]]) 16:45, 23 July 2013 (UTC)

:I've heard this question a few times before, I always just assumed he was lying. He was a rogue and a scoundrel, trying to talk up his knackered old ship. The stuff in the Extended Universe always seemed to take it as gospel that the ship was this amazing super vessel, but I still think it's more likely that he was just spinning a tale. [[User:Elaverick|Elaverick]] ([[User talk:Elaverick|talk]]) 13:48, 12 December 2016 (UTC)

In George Lucas' novelization of the first movie (which I have heard was ghosted by Alan Dean Foster), Obi-Wan remarks to Luke that "Even a duck must be taught how to swim." And Luke replies, "What's a duck?" In another place, Luke was thinking "about a dog he had once owned" right before another event (I believe it was a ship going into hyperspace). [[Special:Contributions/108.162.221.246|108.162.221.246]] 22:08, 22 April 2015 (UTC)

Making the Kessel Run in less than 12 parsecs actually makes sense. The Kessel Run is a run that travels near a black hole, as well as multiple drops into and out of light speed. Therefore, the shorter the distance it took for a pilot to make the run, the faster the ship was (to negate the gravitational pull of the black hole) and the better the pilot was (to be able to maneuver the ship more tightly). So the Kessel Run was actually a race to do it in the shortest ''distance'' possible, not the shortest time. 24 October 2016 [[Special:Contributions/162.158.69.100|162.158.69.100]] 17:38, 24 October 2016 (UTC)

:Honestly, I have to laugh (not at you), as your explanation is very much correct, but the whole situation is ridiculous. What started as a throw-away one-liner brag that seemingly misused an astronomical term has turned into a minor point of debate that was eventually resolved by a film centered around that one line.[[User:Ncpenguin|Ncpenguin]] ([[User talk:Ncpenguin|talk]]) 01:45, 24 May 2022 (UTC)

This same sort of thing also comes up when you think about the names of many rebel/alliance fighters. The Star Wars universe does not use our alphabet. You can probably justify the X-wing since an X is a pretty common symbol outside of being a letter, but one must wonder about all those other letter-wings, like the Y, A, B, H, etc. Fighters shaped after letters that don't seem to exist in Star Wars. {{unsigned ip|172.68.58.53}}

1946: Hawaii

2022-05-21T02:57:03Z

Ncpenguin: Undo revision 270846 by Explain xkcd server admin (talk)

{{comic
| number = 1946
| date = January 24, 2018
| title = Hawaii
| image = hawaii.png
| titletext = Ok, I've got it, just need to plug in my security key. Hmm, which way does the USB go? Nope, not that way. I'll just flip it and-- OH JEEZ IT FELL INTO THE VENT.
}}

==Explanation==

On January 13, 2018, the state of Hawaii {{w|2018_Hawaii_false_missile_alert|sent out an emergency alert}} warning of an incoming {{w|ballistic missile}} attack. The message was specifically noted to NOT be a drill. This caused widespread panic and fear amongst the island residents, and there were follow-up confirmations from local entities who thought the original warning was real. It was eventually determined that the alert was sent in error -- the explanation being that a technician accidentally sent out the "real" version when they were supposed to be testing the system during an end-of-shift changeover -- but the fact that it took around 15 minutes for the correction to be sent drew widespread criticism. On January 23, [http://www.cnn.com/2018/01/23/us/hawaii-governor-password-trnd/index.html it was revealed] that the governor of Hawaii knew the alert was a false alarm only two minutes after it was sent, but couldn't notify the public because he had forgotten the login information for his Twitter account.

The proliferation of online services requiring authentication, together with variations in security requirements, various flavours of {{w|Multi-factor authentication}}, a variety of password retrieval methods, and security advice not to re-use passwords across services, has resulted in the management and memorisation of passwords becoming a major headache for many people. This comic shows Cueball, representing the governor, frantically trying to retrieve his log in to Twitter and encountering a number of common frustrations:
* He has a number of passwords that he uses, likely for multiple services, but none of them seem to be working. Often people will use subtly different variations of one or more password(s) for different logins since logins may require different password requirements. In a situation where they've forgotten the relevant password, this can lead to them cycling through all the possible variations, and struggling to keep track of which they have and haven't tried.
* He's requested a password reset, but doesn't know where to go to activate it. Many services allow users to reset a password using a link or information sent to them in an email. However, as many people have multiple email accounts, this can be unhelpful and frustrating if it simply indicates that 'you have been sent an email'.
* He expects the password to have been saved somewhere, but can't work out where. Many devices and browsers now have the facility to save and/or sync passwords entered through them, in an attempt to simplify their management by providing centralised storage. However, the very number of these available leads to a re-fragmentation.
Off-panel, another person is adding to the stress of his situation by screaming at him that people are beginning to panic and warning sirens are going off, underscoring the need to get the correction out as fast as possible. As the caption under the comic indicates, Randall has had a nightmare along these (very specific) lines, and is amused to find someone experiencing that nightmare in the real world.

The alt-text refers to USB security keys, physical USB devices that act as tangible 'passwords' for various accounts or devices. (A traditional key of shaped metal is literally a tangible password, with each digit of the password releasing one tumbler of a physical lock; Electronic keys replace the key-and-tumbler password system with a digital password signal.) In the context of this comic, the governor attempts to sign into his Twitter account using one such key, but can't insert it into his computer correctly (as USB devices are infamous for needing to be inserted in a particular orientation despite having a symmetrical outer appearance; also known as [https://www.google.com/search?q=usb+superposition USB superposition].) Trying to flip the key around, Cueball drops it into a vent - similar to what happens in [[1518: Typical Morning Routine]].

==Transcript==

:[Cueball is standing, slightly crouched, at a desk with one hand on a laptop and the other holding his phone.]
:Off-screen voice: '''''Hurry!'''''
:Cueball: It keeps saying "Wrong Password!" I've tried everything it might be!
:Off-screen voice: '''''The clock is ticking!'''''
:Cueball: I requested a reset but haven't gotten it! Which email did I use?!
:Off-screen voice: '''''Sirens are going off!!'''''
:Cueball: It's not in my password manager! Is it in a browser? Which browser? Is Autofill synced to my phone??
:Off-screen voice: '''''OH MY GOD THE SCREAMING!!'''''

:[Caption below the panel:]
:I feel bad for everyone in Hawaii, but when the governor couldn't get into his Twitter account, he lived out one of my very specific nightmares in real life.

== Trivia ==
The Hawaii emergency agency also might have password problems. In a news article from June 2017 there was a photo showing an agency employee standing beside his own computer, which sports a password on a sticky note. [http://uk.businessinsider.com/hawaii-emergency-agency-password-discovered-in-photo-sparks-security-criticism-2018-1?utm_content=buffer1f883&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer-ti&r=US&IR=T This caused further criticism of the agency security practices].

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Social networking]]

2328: Space Basketball

2022-05-21T02:56:43Z

Ncpenguin: Undo revision 270881 by Explain xkcd server admin (talk)

{{comic
| number = 2328
| date = July 3, 2020
| title = Space Basketball
| image = space_basketball.png
| titletext = My shooting will improve over the short term, but over the long term the universe will take more shots.
}}

==Explanation==
This is another comic in [[Randall]]'s [[:Category:My Hobby|My Hobby series]], released during the same week as his last hobby comic, [[2326: Five Word Jargon]].

Randall wishes to play basketball against {{w|outer space}}, hence the title ''Space Basketball''. (His previous attempt at creating a "[[2291: New Sports System|New Sports System]]" for multiplayer socially-distant basketball was not very successful.) His goal is to make thirty baskets in a row before the universe puts a {{w|meteor}} through his hoop.

It should be noted that while may be technically correct to call the falling space object in this case a "meteor", when it hits the ground moments later it would be known as a {{w|meteorite}}. See also [[#Terminology|Terminology]] section below. See also [[1405: Meteor]], for what Randall's thoughts are on this.

Randall estimates that his success rate at {{w|free throw|free-throw shooting}} is approximately 30%. Therefore, the chances of Cueball making 30 shots in a row is 0.330, or about 1 in five quadrillion (2×10−16); for comparison, there are approximately 150 quadrillion seconds remaining before the Sun engulfs the earth (5 billion years), so if Randall has a chute set up under the basket and enough basketballs to sustain a constant high rate of shooting, he has "decent" odds of achieving his goal before the Sun burns out. But really, Randall has comparably rapid learning at this task, whereas asteroids have extreme persistence far beyond Randall's life, so when he says the odds are comparable he is abstractly weighing his unique skillset against that of small stellar bodies.
Still, the lifetime odds of being killed by a meteorite have been estimated at 1 in 75,000 or 600,000 or 700,000 [https://www.quora.com/What-is-the-probability-of-me-getting-killed-by-a-meteorite-in-the-next-one-hour]. These calculations are usually based on the probability of being alive at a time when a huge impact kills billions of people. Randall just uses the chance of one meteorite shot on Earth hitting this hoop (hoop-area divided by Earth-area = 3.2×10−16) which is in the same range as 0.330. Actual {{w|meteorite fall statistics}} report an average of 1.2 meteorites per year hitting the European continent which suggests that the average probability of Cueball winning after each shot attempt is about equivalent to a meteorite passing through the hoop over the period of 10 hours. Therefore Cueball has a better chance of winning than the universe "on the short term" if he makes more than 840 free-shot attempts per year for the rest of his life. The expected time for the universe to actually "complete" the challenge would be in the range of 8 billion years, the same magnitude to the current age of the universe and longer than the estimated remaining lifetime of the {{w|solar system}}.

In the title text, Randall assumes that he would get better at free throwing shooting with practice in his lifetime ("the short term"). Some of the world's best basketball players have free-throw percentages over 90%, and even professional players with reputations of being "poor" free-throw shooters (e.g. Shaquille O'Neal) are above 50%. If Randall can improve his percentage to 50%, his odds of sinking thirty baskets in a row improve to "nearly" one-in-a-billion, while a member of the elite {{w|50–40–90 club}} would have a probability better than four percent of making thirty free-throws in a row. Some specialists have achieved much higher success rates, with the record for most consecutive baskets being held by {{w|Tom Amberry}} with 2,750. The NBA regular season record is 97 free throws in a row, set by {{w|Micheal Williams}} in 1993 (during the 1992–93 and 1993 94 seasons).

However, he acknowledges that in "the long term" (the life of the universe, or at least the Earth), the Earth will be hit by very many meteorites; even though it is more likely that Randall will make his thirty free-throws before a meteor passes through his basket, he does not possess the cosmic lifespan{{Citation needed}} required to surmount the odds against him and actually have a good probability to witness either event.

=== Terminology ===
A piece of space debris falling through the atmosphere is a {{w|meteor}}.
A piece of space debris that makes it all the way to the surface of the Earth (or any planet) is a {{w|meteorite}}.
Most meteors burn up completely and do not become meteorites.

The concept of a meteor passing through a basketball hoop, ten feet or less from hitting the ground, is so uncommonly discussed that the terminology could be a matter of some debate. Unless it is ''very'' large, a meteor this close to the ground will have slowed to {{w|terminal velocity}} and will no longer be burning up{{Citation needed}}; it will therefore not be incandescing like a conventional meteor, and it is certain that it will become an actual meteorite within just a moment.

(Any meteor still incandescing within 10 feet of the ground, on the other hand, would presumably destroy both the basketball hoop and any nearby observer, meaning that poor Cueball, if still shooting, would lose the game in a much bigger way.)

Many scientifically-aware people have the habit of correcting "meteor" to "meteorite," so it may be safest to use the latter term among nerds other than Randall, or you could out-nerd them by pedantically pointing out a reason to still call it a meteor.

==Transcript==
:[Cueball, holding a basketball in front of him in both hands, is looking up at the basketball hoop in front of him. The hoop is on a standard board, but at the foot of the rod holding the hoop, there seems to be growing grass up, indicating it is outside.]
:Cueball: Okay, here are the rules:
:Cueball: I have to make 30 shots in a row before a meteor falls through the hoop.
:Cueball: I'm a 30% free throw shooter so the odds are actually pretty even.
:Cueball: Ready...Go!

:[Caption below panel:]
:My hobby: playing basketball against space

{{comic discussion}}

[[Category:My Hobby]]
[[Category:Comics featuring Cueball]]
[[Category:Basketball]]
[[Category:Astronomy]]

1007: Sustainable

2022-05-21T02:56:29Z

Ncpenguin: Undo revision 270854 by Explain xkcd server admin (talk)

{{comic
| number = 1007
| date = January 23, 2012
| title = Sustainable
| image = sustainable.png
| titletext = Though 100 years is longer than a lot of our resources.
}}
==Explanation==
This is a simple scatterplot showing how often the word "sustainable" has been used in English texts in the US each year. As can be seen, the y-axis is given a logarithmic scale, meaning that the apparently linear trend is actually exponential. [[Randall]] [[605: Extrapolating|humorously attempts to extend the graph]] to the point the frequency exceeds 100% about a century from now, which is obviously impossible (hence the quip that the word's usage is itself "unsustainable").

The use of the word "sustainable" has been increasing as people become more aware of the steadily increasing use of nonrenewable resources and need to ensure that the Earth's resources do not become totally exhausted, through sustainable development. {{w|Sustainable development}} refers to the practice of using resources that simultaneously aims to meet human needs while preserving the environment so that these needs can be met not only in the present time, but also for generations to come.

As Randall somewhat depressingly mentions in the title text, the ~100 years that it will supposedly take for the word "sustainable" to become unsustainable is actually a lot longer than most of our nonrenewable resources will last on the Earth. The idea that ''all'' of the Earth's coal, oil, natural gas, etc. that has built up over the past millions of years may be completely gone within the century is unsettling.

More realistically, the actual use of "sustainable" is likely to be logistic rather than exponential growth. A logistic curve describes a trend that at first behaves exponentially, but then tapers off and reaches a cap. This is demonstrated by the [https://books.google.com/ngrams/graph?content=sustainable&year_start=1940&year_end=2014&corpus=15&smoothing=3&share=&direct_url=t1%3B%2Csustainable%3B%2Cc0 Google ngrams graph of word usage for "sustainable"]. Logistic growth is commonly used to model data that naturally increases exponentially but has a limiting factor, which in this case is the meaningfulness of text consisting entirely or mostly of a single word.

This comic was used in the 2018 book ''[https://books.google.ca/books?id=J6grDwAAQBAJ&pg=PA128&lpg=PA128&dq=enlightenment+now+xkcd&source=bl&ots=8LvAVHQU2_&sig=ACfU3U27rxPWl4N8-muk1eRSm0BMMqWoHA&hl=en&sa=X&ved=2ahUKEwjOkIne-rTkAhUYs54KHRCZCHsQ6AEwEHoECAkQAQ#v=onepage&q=enlightenment%20now%20xkcd&f=false| Enlightenment Now: The Case for Reason, Science, Humanism, and Progress]'' by Steven Pinker as it discusses the concept of sustainable energy.

Extrapolation of data has also appeared in the following comics [[605: Extrapolating]], [[1204: Detail]] and [[1281: Minifigs]]. And yes, "sustainable" has appeared in every paragraph so far.

==Transcript==
:[A large two-axis scatterplot graph with a caption below. The y-axis displays percentages on a logarithmic scale from 0.000001% to 1,000%, and is labeled "Frequency of use of the word "sustainable" in US English text, as a percentage of all words, by year. Source: Google NGrams." The x-axis displays years from 1950 to 2140, and is labeled "Year". Plotted data points show a high linear correlation (effectively exponential due to being a log scale), ranging from approximately 0.000005% in 1960 to approximately 0.003% in 2012. A linear trend line is drawn through the data points, and is extrapolated to the end of the graph. Four points on this trend line are marked and labled:]

:(2012, ~0.003%): Present Day
:(2036, ~0.03%): 2036: "Sustainable" occurs an average of once per page
:(2061, ~0.5%): 2061: "Sustainable" occurs an average of once per sentence
:(2109, 100%): 2109: All sentences are just the word "sustainable" over and over.

:[The trend line continues past the year 2109, exceeding 100% and breaking up into question marks.]

:[Caption below the panel:]
:The word "sustainable" is unsustainable.

{{comic discussion}}
[[Category:Line graphs]]
[[Category:Extrapolation]]

967: Prairie

2022-05-21T02:56:17Z

Ncpenguin: Undo revision 270965 by Explain xkcd server admin (talk)

{{comic
| number = 967
| date = October 21, 2011
| title = Prairie
| image = prairie.png
| titletext = Colorado is working to develop coherent amber waves, which would allow them to finally destroy Kansas and Nebraska with a devastating but majestic grain laser.
}}

==Explanation==
This comic refers to the song ''{{w|America the Beautiful}}'', which contains the line "amber waves of grain," which refers to the plentiful wheat fields in the Midwestern US. The ''waves,'' in this context, are being likened to the waves in the ocean, as the wind can make the wheat move in such a way as to resemble waves.

In {{w|quantum mechanics}} the wave-particle duality explains that particles can act like both particles and waves, depending on the context. Using a comedic adaptation of quantum theory, [[Megan]] states that the waves of grain become particles of grain when observed, which, in a way, is true. However, this is not a perfect analogy because each grain is a separate entity while an external force, the wind, is what produces the wave motion.

The title text builds on the quantum mechanics principle that a laser is a {{w|Coherent states|coherent wave}}. This leads of the absurd notion that one could harness waves in grain fields for use as a laser weapon, which would be used by one state to destroy two neighbors. There is a long running joke in the Rocky Mountain West of completely obliterating nearby states, and in particular Nebraska. The use of the word "majestic" to describe the laser is a reference to another line in "America the Beautiful" — "for purple mountain majesties" — which does in fact allude to the Rocky Mountains in Colorado.

==Transcript==
:[Megan and Cueball stand in a field of wheat, facing away from the panel. The figures are drawn in the typical black and white stick figure style, but the field is immensely detailed, with the grain coloured a rich amber and stroked such that individual stalks can be picked out, with a few dark bands providing contrast. In the distance a low mountain range is visible and in the sky a few scattered fluffy white clouds float low over the horizon.]
:Megan: Well, when we observe them, they become amber ''particles'' of grain.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics with color]]
[[Category:Physics]]

1944: The End of the Rainbow

2022-05-21T02:55:51Z

Ncpenguin: Undo revision 270883 by Explain xkcd server admin (talk)

{{comic
| number = 1944
| date = January 19, 2018
| title = The End of the Rainbow
| image = the_end_of_the_rainbow.png
| titletext = The retina is the exposed surface of the brain, so if you think about a pot of gold while looking at a rainbow, then there's one at BOTH ends.
}}

==Explanation==

[[Megan]] appears to reference the myth that at the end of every {{w|rainbow}} lies a {{w|leprechaun}}'s pot of gold. Instead of claiming that leprechauns and their gold don't exist, [[Cueball]] offers the refutation that, technically, {{w|File:Circular_rainbow.jpg|rainbows are circles}}, so they do not have an end. This is true for an idealised rainbow, and for some actual rainbows: if the viewer has an unobstructed view of the light-reflecting substance creating the effect for the whole of the circle's circumference, they could see a full circle. In practice, the circle is often broken by the horizon or, for example, discontinuity in cloud cover.

However, Megan counters that if one considers the path that light takes to form a rainbow, then it forms a two-cone structure, where the Sun (the vertex of the outer cone) emits light rays that move towards the Earth (forming the faces of the outer cone), then reflect off water droplets located at just the right angle (the circular base) to reach our eyes (the vertex of the inner cone). Thus, such a rainbow structure ''can'' be said to have "ends", represented by the vertices of the two cones: one at the eye of the viewer, and another at the light source (usually the sun).
A common rainbow (which base is formed by a water droplets in the Earth's atmosphere) can not be viewed as that. The Sun's diameter is orders of magnitude greater than Earth's one (even including the outer layers of the atmosphere), and we would expect the apex of a cone to be much smaller than its base. Thus a two-cone rainbow which starts in Sun shall have its base formed in the outer space.

Megan then says that the Sun is indeed a pot of gold. The Sun is approximately [https://nssdc.gsfc.nasa.gov/planetary/factsheet/sunfact.html 1.989 × 1030 (1 nonillion 989 octillion) kilograms], and its abundance of gold is approximately [http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1968PASAu...1..133A&data_type=PDF_HIGH&filetype=.pdf&type=PRINTER&whole_paper=YES 0.3 parts per trillion] (ed: this value is incorrect - values in the paper are not in ppt - see comments below). Based on these numbers, the sun contains 5.967 × 1017 (596 quadrillion 700 trillion) kilograms of gold. This equates to 5.967 × 1014 (596 trillion 700 billion) metric tons of gold. As such, Megan's statement that the sun contains "quintillions of tons of gold" is off by a factor of roughly 4000, but the amount of gold within the sun is, nonetheless, far more than a pot's worth.{{Citation needed}}

The amount of water in the oceans is about [https://phys.org/news/2014-12-percent-earth.html 1.35 × 1018 (1 quintillion 350 quadrillion) metric tons]. If we assume that Megan is still talking in terms of mass rather than volume or molecule count, then her next statement (that there is more gold in the sun than water in the oceans) would have been true had she been correct in her previous claim, but in fact there is more sea-water than sun-gold by a factor of roughly 2300.

Cueball then asks about leprechauns (perhaps ironically, since Megan's theory at this point appears to involve astronomy/physics, not mythical creatures/beings). Megan replies that the leprechauns all died when the Sun formed, building on the irony of Cueball's question (& opening questions about the role of leprechauns in the early formation of our solar system).

The title text suggests that, since the pot of gold exists as an idea in the brains of people thinking about it, and the retina is the foremost part of the brain for light perception, it can be argued that, in addition to existing in the sun as the comic explains, the gold (and leprechauns) also exist at the perceiver's end of the cone, as long as they are thinking about a pot of gold at the time (and then it's gone as soon as they stop thinking about it). Many neurologists would agree with the concept that ideas in your mind can be said to be physically located in your brain. However, this seems to go further, and suggest an {{w|Idealism|idealist}} ontological position, that things, in this case a pot of gold, exist by virtue of our having an idea of them.

==Transcript==

:[Megan and Cueball are walking.]
:Megan: There's a pot of gold at the end of the rainbow.
:Cueball: Rainbows are circles. They have no end.
:Megan: Not quite!

:[In a borderless panel, a multi-part graphic is shown depicting what Megan is describing off-panel: a short cone inside a longer cone, with the longer cone having its point starting at the Sun, the shorter cone having its point at a miniature Cueball's head, and both cones sharing the same circular base. The diagram is repeated from 3 different perspectives to make the structure easier to grasp.]
:Megan (off-panel): A '''rainbow''' is light leaving the Sun, bouncing off the clouds, and converging on your eye. It's an inside-out two-ended cone.

:[Megan and Cueball are still walking.]
:Megan: One end of that cone is your retina.

:[A wider view of the same scene, with Megan and Cueball walking on a dark ground.]
:Megan: The other end is the Sun—which contains quintillions of tons of gold. There's more gold in the Sun than water in the oceans.
:Cueball: So there ''is'' a pot of gold!
:Cueball: What about leprechauns?
:Megan: All incinerated as the sun formed. Very sad.

==Trivia==

As of January 19, 2017, the value of gold is 42,692.98 USD per kilogram. Based on this, all of the gold in the sun is worth 2.5474901 × 10^22 (25 sextillion 474 quintillion 901 quadrillion) USD. Of course, if you tried to sell the gold in the sun, the market would be saturated and the value of gold would plummet astronomically. You would never be able to cash out.

The idea that the Sun is valuable in monetary terms is also present in [[1622: Henge]].

{{comic discussion}}
[[Category:Comics_featuring_Megan]]
[[Category:Comics_featuring_Cueball]]

716: Time Machine

2022-05-21T02:55:16Z

Ncpenguin: Undo revision 271088 by Explain xkcd server admin (talk)

{{comic
| number = 716
| date = March 19, 2010
| title = Time Machine
| image = time_machine.png
| titletext = We never see any time travelers because they all discover it's a huge mistake. This is also why your friend at the lab suddenly looked a year older recently.
}}

==Explanation==
[[Rob]] is about to discover {{w|Time travel|time traveling}}, but a future version of him comes back in time and hits him with a baseball bat before he can actually build this time machine.

A common theme in time travel fiction is going back into the past to fix some mistake or stop some tragedy before it happens (see for instance {{w|The Terminator}} movies). In this comic, it is implied that Rob's time traveling turned out to cause a tragedy of some kind, so in order to stop it, Future-Rob must go back in time to stop himself from time traveling in the first place. The last panel supports this by suggesting that at least once a month somebody discovers time travel, but inevitably ends up going back in time to prevent themselves from doing so.

This is a plot point from the 2004 time-travel drama film [[wikipedia:Primer (film)|''Primer'']]: one character intends to travel back in time to prevent them from discovering time travel in this way, and another character has already traveled back in time, drugged his earlier self, and taken over the operation to discover time travel before the narrative of the film begins. ''Primer'' has a notoriously complicated plot that Randall already has made a jocular attempt at explaining in [[657: Movie Narrative Charts]]. Some more thorough attempts to explain it can be found [http://movies.stackexchange.com/questions/334/can-someone-explain-the-sequence-of-events-in-primer here] and [http://qntm.org/primer here]. Doubtless, this has also been spoofed in countless other comedic settings.

The blood on the bat suggests that future Rob actually killed past Rob. This is of course a paradox like the {{w|grandfather paradox}} - but there are theories about how it would still be possible - see the link. The obvious paradox is that when Rob dies the future Rob never existed. But also the time travel Future Rob undertakes uses a technique that is now never invented. This was the reason for future Rob's travel.

The title text states that this is why we never see any time travelers since they would have stopped their own past selves from time traveling. After getting rid of their past selves they would then assume their place in the timeline, hence why a friend would suddenly look older: they ''have'' aged, just in another timeline before returning to the past.

==Transcript==
:[Rob is working at a workbench. Future-Rob appears out of nowhere with a baseball bat.]
:Future-Rob: Hi, Rob.
:Rob: Whoa, you're me!

:[Future-Rob holding the baseball bat, standing next to Rob.]
:Future-Rob: You're about to have an idea for a time machine.
:Rob: I am?

:[In a frameless panel, Future-Rob hits Rob over the head with the baseball bat.]
:''WHAM''

:[Megan approaches Future-Rob working at the workbench, with Rob nowhere to be seen. The bloody baseball bat is stashed behind it.]
:Megan: Hey, Rob. What's up?
:Future-Rob: Nothing.

:[Caption below the last panel:]
:This happens somewhere roughly once a month.

==Trivia==
This comic's title is very similar to [[1203: Time Machines]].

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Rob]]
[[Category:Comics featuring Megan]]
[[Category:Time travel]]
[[Category:Baseball]]
[[Category:Comics with blood]]
[[Category:Multiple Cueballs]]
[[Category:Comics sharing name|Time Machine]]

792: Password Reuse

2022-05-21T02:55:05Z

Ncpenguin: Undo revision 271037 by Explain xkcd server admin (talk)

{{comic
| number = 792
| date = September 13, 2010
| title = Password Reuse
| image = password_reuse.png
| titletext = It'll be hilarious the first few times this happens.
}}

==Explanation==
This comic has three layers: hacking, philosophy, and Google satire.

It starts off on a practical level, with [[Black Hat]] describing to [[Cueball]] a devious social engineering scheme. It relies on the fact that people commonly reuse the same password on multiple websites, and tend to create accounts on new websites somewhat indiscriminately. Thus, one could create a simple Web service to collect users' usernames, email addresses, and passwords. Since many users will reuse this combination on other websites as well, the website owner can try to hack their accounts on other common sites, such as {{w|Amazon.com|Amazon}}, {{w|PayPal}} or even people's banks, using the same login information.

In panel 7, the comic suddenly develops a philosophical and ethical bent. Black Hat reveals that he has already carried out step 1, through his numerous unprofitable Web services which he had been running for this very purpose. However, after successfully executing the hack, he realizes that he does not know what to do with all this power.

He reveals that he is already financially self-sufficient, and makes a point that money can't buy happiness once past that point, stating that research has proven this. He could use his power to realize his sadistic pleasures of messing with people, but he's already a serial [[72: Classhole|classhole]] and does not need this information to continue that trend.

If he had any beliefs or ideology, he could use this power to try to spread them. However, he reveals that "since {{w|March_1997#March|March of 1997}}" he doesn't really believe in anything. While he doesn't reveal specifically what in March of 1997 caused this, it could possibly refer to the {{w|Heaven's Gate (religious group)#Mass suicide and aftermath|March 26, 1997 incident}} in San Diego, California, where 39 {{w|Heaven's Gate (religious group)|Heaven's Gate}} cultists committed mass suicide at their compound. One of the cultists was the brother of {{w|Nichelle Nichols}} (a {{w|Star Trek}} actress), so the event got a big resonance in nerd circles (and [[Randall]] [[:Category:Star Trek|often references Star Trek]] in xkcd). However, given Black Hat's strange behavior, it could be anything, from {{w|Bill Clinton}} banning federal funding for {{w|human cloning}} research on the fourth, to the launch of {{w|Teletubbies}} on the thirty first. Later, in [[1717: Pyramid Honey]], Black Hat seems to finally find something to believe in.

The dilemma: Black Hat has cleverly executed a hack that has given him a lot of power, but he doesn't know what to do with it.

The last part of the comic now transitions to a satire on how {{w|Google}} has already gone through both the stages described above. It describes how all of Google's free services are simply a ploy to collect and control all the world's information, similar in concept but grander than the hack described in part 1. It satirizes the notion that behind Google's "Don't be evil" motto is actually an end-goal of using their powers eventually for evil. (Google has since removed the motto from their code of conduct, so maybe Randall's on to something...)

However, just like Black Hat, once Google reaches the stage where they are able to capitalize on their powers, the Cueball-like head-executive finds that there is nothing evil left for them to desire, except (as [[Hairbun]] states) make even more money. As they already make a lot of money this ploy is moot, and anything remaining that they wish to do, such as hosting {{w|Call of Duty}} (CoD) tournaments, isn't evil at all.

In the end, the secretary calls dibs on the TV in the lobby in order to play CoD4 on what (one can assume) is a large screen. The Cueball-like executive who wished to implement the evil plan in the first place {{w|facepalm|facepalms}} when he realizes that Google just sucks at being evil.

In the title text, “The first few times this happens” may refer to the weekly CoD4 “tournament.” Alternatively, it could also mean the “first few times” a company decides to turn evil (but then has no idea how). It could also refer to the first couple of times an individual follows through on this plan but fails after the first part due to a lack of planning for the second part.

This comic was directly referenced in the title text of [[1286: Encryptic]].

==Transcript==
:[Black Hat is standing to the left behind Cueball, who is sitting in an office chair at his desk working on his computer. A message from the computer is indicated with a zigzag line from the screen.]
:Black Hat: Password entropy is rarely relevant. The real modern danger is password reuse.
:Cueball: How so?
:Computer: Password too weak

:[Zoom in on Black Hat's upper part as he holds a hand up with the palm up.]
:Black Hat: Set up a Web service to do something simple, like image hosting or tweet syndication, so a few million people set up free accounts.

:[Zoom out to Black Hat standing in front of Cueball who has turned in the chair facing Black Hat, the desk is not shown in the panel.]
:Black Hat: Bam, you've got a few million emails, default usernames, and passwords.

:[Only Black Hat is shown as he holds out his arms.]
:Black Hat: Tons of people use one password, strong or not, for most accounts.

:[The next panel is only half the height of the other panels. Above the panel is the text that Black Hat narrates. In the left part of the panel, there is a piece of paper that seems to have been torn off at the bottom resulting in a jagged edge, which could also indicate that it continues further down than shown. On the paper, there are three labeled columns, and below each of them about 18 lines of unreadable sentences (mostly just one word). The @ in the e-mail addresses may be indicated with a larger unreadable sign. To the right a broad line goes right from the paper and splits up in five lines that go up or down ending in five arrows to the right, pointing at five labels.]
:Black Hat (narrating): Use the list and some proxies to try automated logins to the 20 or 30 most popular sites, plus banks and PayPal and such.
:Labels on paper: Email User Pass
:Labels at arrows:
::Banks
::Facebook
::Gmail
::PayPal
::Twitter

:[Same setting as panel 3 but Cueball has taken a hand to his chin.]
:Black Hat: You've now got a few hundred thousand real identities on a few dozen services, and nobody suspects a thing.
:Cueball: And then what?

:[Same setting in a larger panel with more white space to the left, Cueball has his hand down again.]
:Black Hat: Well, that's where I got stuck.
:Cueball: You did this?
:Black Hat: Why do you '''''think''''' I hosted so many unprofitable web services?

:[Zoom in on Black Hat's head now turned towards left.]
:Black Hat: I could probably net in a lot of money, one way or another, if I did things carefully. But research shows more money doesn't make people happier, once they make enough to avoid day-to-day financial stress.

:[Zooming a bit out, but still only showing Black Hat's head in the bottom right corner, again facing right.]
:Black Hat: I could mess with people endlessly, but I do that already. I could get a political or religious idea out to most of the world, but since March of 1997 I don't really believe in anything.

:[This panel is the last in this row, but it does not reach the end of the row above, an indication that this does not directly belong to the panels below. The same setting as panel 3 but Black Hat has his arms out.]
:Black Hat: So, here I sit, a puppetmaster who wants nothing from his puppets.
:Black Hat: It's the same problem Google has.
:Cueball: Oh?

:[This panel is the first in the last row. It does not begin to the left, but has been shifted a bit to the right, just as the last panel above to the right, ended before reaching the right edge of the row above (and this one below). This is to indicate that this is row has a different story. A Cueball-like executive at Google is standing up leaning his arms on a table with Google's logo on the side. His office chair has been pushed to the left behind him and it is partly off-panel. He addresses the other executives at the table, two of which are shown. The first is Hairbun with glasses holding her head with both hands, elbows resting on the table. The other executive is also a Cueball-like guy, his head is partly outside the right edge of the panel. At the top of the panel to the left, there is a small frame breaking the panel's frame, inside which is a caption:]
:Google...
:Cueball executive: Okay, everyone, we control the world's information. Now it's time to turn evil. What's the plan?
:Hairbun: Make boatloads of money?
:Table: Google

:[Only the Cueball-like executive standing at the end of the table is shown, the table is left out. He is face-palming. One of the executives at the table is speaking off-panel. Could be either of the two above or someone not shown before]
:Cueball executive: We already do!
:Executive (off-panel): Set up a companywide CoD4: Modern Warfare tournament each week?
:Cueball executive: ''That's not evil!''
:Executive (off-panel): Ooh, Dibs on the lobby TV!
:Cueball executive: Okay, we ''suck'' at this.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Hairbun]]
[[Category:Multiple Cueballs]]
[[Category:Social networking]]
[[Category:Video games]]
[[Category:Computer security]]
[[Category:Identity Theft]]

1241: Annoying Ringtone Champion

2022-05-21T02:54:42Z

Ncpenguin: Undo revision 271011 by Explain xkcd server admin (talk)

{{comic
| number = 1241
| date = July 22, 2013
| title = Annoying Ringtone Champion
| image = annoying_ringtone_champion.png
| titletext = It beat out 'Clock radio alarm', 'B-flat at 194 decibels', 'That noise from Dumb & Dumber', and 'Recording of a sobbing voice begging you to answer'.
}}

==Explanation==
This comic satirizes the large variety of {{w|Ringtone|ringtones}} that may be used on their cell phones. While many are simply tunes that personalize a user's phone, some will use ringtones that resemble everyday sounds, such as doorbells, coughing, alarm noises, or in this case, the buzzing of a mosquito. Although rather innocuous, these ringtones can get very annoying to some people, which is what this comic is getting at.

Here, [[Black Hat]] has set his ringtone to "The sound a mosquito makes as it buzzes past your ear", the winner of the "Awful Ringtone Championship". [[Cueball]], hearing the sound, cries out and swats the air around his head, mistaking the ringtone for an actual mosquito buzzing past his ear. In addition to being an extremely unpleasant sound, it could also cause confusion to others, as shown in the comic, thus being unanimously decided as the most annoying ringtone. [[Black Hat]]'s response is likely a pun meaning both "Oh, I've got to take this [call]" (like someone who has been interrupted by a phone call) and need to leave and respond and "Oh, I've got to take this [competition]" since the ringtone is so annoying.

The title text refers to four other annoying ringtones, apparently none of which were deemed as annoying as a mosquito buzzing:
*"Clock radio alarm". These sounds are often loud and annoying, just to ensure that you really will wake up.
*"B-flat at 194 decibels". {{w|B♭ (musical note)|B-flat}} is a musical note with a pitch of 466.16 Hz. 194 decibels is 501187233627% (most devices only go up to 100%/0dB) and is the {{w|Sound pressure#Examples of sound pressure and sound pressure levels|limit at 1 atmosphere pressure}}. Any more energy would create a shockwave. This could also be a reference to a crowd of {{w|vuvuzela}}s as they also produce sounds pitched around B flat. This may also refer to several B-flat-related phenomena discussed in an NPR story, [http://www.npr.org/templates/story/story.php?storyId=7442915 Have You Heard About B Flat?] Specifically, B-flat has been found to agitate alligators, and waves passing through gas near a black hole have been found to resonate at a frequency which results in a B flat 57 octaves below middle C. Regardless of all this, a sound played as loud as 194 dB is quite literally deafening, so the ringtone would be not so much annoying as dangerous.
*"That noise from Dumb & Dumber". {{w|Dumb and Dumber}} is a comedy movie from 1994. [http://www.youtube.com/watch?v=0cVlTeIATBs The noise] from Dumb & Dumber is referring to the point in the movie when Harry and Lloyd asked, "Do you want to hear the most annoying sound in the world?" and began shrieking in imitation of a loud fax machine.
*"Recording of a sobbing voice begging you to answer". Self-explanatory. Such a ringtone is obviously disruptive, annoying, and potentially worrying to those in the vicinity of the phone.

==Transcript==
:[At the top of the frame is an annoying humming tone shown. Cueball is cringing while raising his arms above his head. Black Hat pulls out his phone looking at it.]
:Ringtone: hMMMMMM<big>M<big>M<big>M</big>M</big></big>MMMMMMMM
:Cueball: <big>Augh!</big>
:Black Hat: Oh, I've gotta take this.

:[Caption below the frame:]
:By unanimous decision, the winner of the Awful Ringtone Championship is "the sound a mosquito makes as it buzzes past your ear".

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Rankings]] 
[[Category:Phones]]
[[Category:Music]]

110: Clark Gable

2022-05-21T02:54:15Z

Ncpenguin: Undo revision 270952 by Explain xkcd server admin (talk)

{{comic
| number = 110
| date = June 2, 2006
| title = Clark Gable
| image = clark_gable.jpg
| titletext = Frankly, my dear, I don't give a BITCH ASS SHIT FUCK DAMN
}}

==Explanation==
"Frankly, my dear, I don't give a damn" is the signature catchphrase from the 1939 movie ''{{w|Gone With The Wind (film)|Gone With The Wind}}'', which starred {{w|Clark Gable}} and {{w|Vivien Leigh}}. The phrase is spoken by Gable's character {{w|Rhett Butler}} as his last line, in answer to {{w|Scarlett O'Hara}} (Leigh) asking "Where shall I go? What shall I do?" The response indicates that Butler is no longer interested in O'Hara. This lack of interest, and the mention of the word "damn," which was considered profanity at the time of releasing the film, led to the line being voted the #1 movie line of all time in 1995's American Film Institute ranking.

[[Randall Munroe|Randall]] suggests that the line as written was not supposed to contain profanity, but the actor, Gable, inserted it, due to having {{w|Tourette's Syndrome}}, which is a neurological condition that is stereotypically characterized by bouts of random, uncontrollable cursing (and repetition of phrases/words).

The title text contains a more stereotypical Tourette's Syndrome outburst of several profanities in a row shouted mid-sentence.

==Transcript==
:[Famous image of ''Gone with the Wind'' with Rhett Butler (Clark Gable) kissing Scarlett O'Hara (Vivien Leigh).]
:The line was actually supposed to be "Frankly, my dear, I couldn't care less." It's just that Clark Gable had Tourette's.

{{comic discussion}}
[[Category:Language]]
[[Category:Romance]]
[[Category:Comics featuring real people]]

2397: I Just Don't Trust Them

2022-05-21T02:53:40Z

Ncpenguin: Undo revision 270909 by Explain xkcd server admin (talk)

{{comic
| number = 2397
| date = December 11, 2020
| title = I Just Don't Trust Them
| image = i_just_dont_trust_them.png
| titletext = I believe in getting immunity the old-fashioned way: By letting a bat virus take control of my lungs and turn my face into a disgusting plague fountain while my immune system desperately Googles 'how to make spike protein antibodies'.
}}

==Explanation==
This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|COVID-19 pandemic}}, specifically regarding the [[:Category:COVID-19 vaccine|COVID-19 vaccine]].

[[Cueball]] partially echoes a statement made by {{w|Vaccine hesitancy|anti-vaccination}} activists about "{{w|Big_Pharma_conspiracy theory|Big Pharma}}" (the powerful and profit-driven companies which develop pharmaceutical drugs such as {{w|vaccines}}). Anti-vaccine protesters falsely believe that vaccines contain harmful toxins (such as HIV proteins, {{rw|Anti-vaccination_movement#Aluminum|aluminum salts}}, formaldehyde, {{rw|Thiomersal|mercury}}, and nanoparticles) that cause ill effects on the human body, that just because there has never been a licensed mRNA vaccine before that these new vaccines are not safe in the long term, and that the corporations that make them are not to be trusted because they are exploiting a captive public for profit while disregarding public health. The joke is that Cueball is revealed to be not talking about Big Pharma but, instead, bats.

According to the WHO, COVID-19 has an ecological origin in bat populations. Hence, Cueball sees the virus as something developed by bats, and the ambiguity by which he expresses his desire to not be infected adds to the joke.

The comic could simply be seen to serve as a compelling argument against the anti-vaccine movement, which is often criticized for spreading misinformation and increasing rates of disease, especially since the start of the COVID-19 pandemic. This comic comes shortly after the news of the development of several COVID-19 vaccines with high rates of success; there are concerns that herd immunity may be delayed if people refuse to take the vaccine.

The title text refers to getting immunity the old-fashioned way, i.e. catching the disease and waiting for your immune system to build up a response. This is usually considered healthy when immunity to minor diseases is common, and can avoid the sudden forced evolution of new diseases among extensively hypercareful communities, but developing natural immunity is certainly incredibly dangerous during a pandemic of a serious illness. One joke here is that many anti-vaxxers claim that it is more natural to not take a vaccine. Because many people conflate "natural" with "healthy", the assumption underlying the claim "it is more natural to not take a vaccine" is that it is therefore more healthy. Such arguments are an example of the {{rw|fallacy|logical fallacy}} known as {{rw|Appeal_to_nature|Appeal to nature}}. Thus, the title text is apparently written from a pro-vaxxer's take on the stance of an anti-vaxxer.

The title text also playfully suggests that the immune system would attempt to use an Internet search engine to learn how to manufacture {{w|Coronavirus spike protein|spike protein}} {{w|antibody|antibodies}}. While this may be an effective technique for a human being to acquire knowledge, it would not likely be as efficient for a nonsentient biological system.{{Citation needed}}

==Transcript==
:[Cueball stands with his arms to his sides, facing Megan.]
:Cueball: I just don't trust them, and I don't want to put something they developed into my body.

:[Caption below the panel:]
:How I feel about bats

{{comic discussion}}

[[Category:COVID-19]]
[[Category:COVID-19 vaccine]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Animals]]
[[Category:Biology]]

194: Penises

2022-05-21T02:53:25Z

Ncpenguin: Undo revision 270867 by Explain xkcd server admin (talk)

{{comic
| number = 194
| date = December 8, 2006
| title = Penises
| image = penises.png
| titletext = The penis varies in size when flaccid and is pretty consistently about yea big when erect. Anyway, back to the sitcom one-liners and the constant flow of spam.
}}
==Explanation==
The comic takes aim at what is considered by some to be the apparent societal obsession with the {{w|human penis|male sexual organ}} ("phallocentrism"), especially in regards to size. In general, depictions of an erect penis (also called {{w|phallus}}) represent male potency.

While present in every human civilization, the symbol of the penis is also prominently featured in modern mass media. Many films and television series make use of penis-related jokes. A very common trope is the male obsession with the idea that a larger penis is considered more desirable, and a smaller penis less manly or satisfying to women.

Megan criticizes this obsession by pointing out that most penises are about the same size, and normal variations in size are not worth getting worked up about.

The title text refers to the excessive advertisement for {{w|Sildenafil|potency pills}} and {{w|penis enlargement}} in {{w|Email spam|spam emails}}. The symbol of the phallus can be regarded by some as omnipresent in modern Western society (but not necessarily in other cultures){{Citation needed}}, with presumably every public toilet sporting at least one badly drawn depiction of a penis.

==Transcript==
:PENISES:
:Megan: They are about this big.
:[Holds her hands close together, about half a foot apart.]
:Now can we PLEASE, as a culture, move on?

{{comic discussion}}
[[Category:Comics featuring Megan‏‎]]
[[Category:Penis]]

1447: Meta-Analysis

2022-05-21T02:53:12Z

Ncpenguin: Undo revision 270907 by Explain xkcd server admin (talk)

{{comic
| number = 1447
| date = November 14, 2014
| title = Meta-Analysis
| image = meta-analysis.png
| titletext = Life goal #29 is to get enough of them rejected that I can publish a comparative analysis of the rejection letters.
}}

==Explanation==
In the scientific literature, meta-analyses are studies which compare multiple studies on a single topic, with the aim of giving a balanced overview of the known results. [http://www.medline.com/ Medline], [http://www.elsevier.com/online-tools/embase/about Embase] and [http://www.cochrane.org/ Cochrane] are medical research databases which give access to studies on drug effects or results of other medical procedures.

This comic explores the idea of iterating the process, going from meta-analyses to meta-meta-analyses (which actually exist, though not necessarily by that name, see below) and hence to a meta-meta-meta-analysis.

Of course, the title text adds another level of meta-analysis, since he wants to make a meta-analysis of rejection letters which concern his meta-meta-meta analyses.

All of the cited meta-meta-analyses are real: [http://dx.doi.org/10.1016/S0895-4356(03)00110-0 M. Sampson (2003)], [http://dx.doi.org/10.1111/j.1464-5491.2005.01645.x P. L. Royle (2005)], [http://dx.doi.org/10.1016/j.jpainsymman.2011.01.007 E. Lee (2011)], and [http://dx.doi.org/10.1016/j.jclinepi.2005.03.004 A.R. Lemeshow (2005)].

The phrase "too meta" can be found in the comments of videos, blog posts, and other internet content for which the commentator claims they are so abstract that they can't be easily interpreted. It refers to the thing in question being too self-referential, but could just be a cursory dismisal of the presented content.

Comic [[93: Jeremy Irons]] similarly states a slightly absurd "life goal". [[917: Hofstadter]] is "meta"-related.

==Transcript==
:[Excerpt from a scientific paper.]
:Many meta-analysis studies include the phrase “We searched Medline, Embase, and Cochrane for studies…”
:This has led to meta-meta-analyses comparing meta-analysis methods. e.g. M Sampson (2003), PL Royle (2005), E Lee (2011), AR Lemeshow (2005).
:We performed a meta-meta-meta-analysis of these meta-meta-analyses.
:Methods: We searched Medline, Embase, and Cochrane for the phrase “We searched Medline, Embase, and Cochrane for the phrase ‘We searched Medline, Embase, and [cut off]

:[Caption below the panel:]
:Life goal #28: get a paper rejected with the comment “Too meta”

{{comic discussion}}
[[Category:Science]]
[[Category: Research Papers]]
[[Category:Self-reference]]

697: Tensile vs. Shear Strength

2022-05-21T02:52:55Z

Ncpenguin: Undo revision 270911 by Explain xkcd server admin (talk)

{{comic
| number = 697
| date = February 3, 2010
| title = Tensile vs. Shear Strength
| image = tensile_vs_shear_strength.png
| titletext = Although really, the damage was done when the party planners took the hole punch to the elevator ribbon to hang up the sign.
}}

==Explanation==
Tensile strength represents how hard you can pull on something without it breaking. Shear strength represents how hard you can try to cut it without it breaking. Many materials have great tensile strength but low shear strength (such as dental floss — try to break it by just pulling on two ends), including whatever this space elevator is made of. The material clearly has extremely high tensile strength because it can hold the elevator in place, with one end on the ground and one in space, but it can be cut with a simple pair of pruning shears. This also highlights the fact that "shear strength" and "shears" are [https://www.etymonline.com/word/shear etymologically related].

A {{w|space elevator}} is a proposed construction that would make space travel easier. It consists of a long string attached to the Earth (near equator) on one end and a counterweight (beyond the {{w|geostationary orbit}}) on the other end, kept taut and in one place by the gravity and centrifugal forces. This would make it possible to carry spacecraft into the orbit by simple mechanical means, as opposed to requiring the use of rockets as is the case nowadays, saving a lot of energy and resources.

The phrase "a modern Babel" refers to the biblical story of the {{w|Tower of Babel}} (later referenced in [[2421: Tower of Babel]]), in which humans endeavor to build a tower reaching heaven. Their arrogance angers God and prompts him to sabotage the project. A space elevator can be seen as a modern equivalent of a tower to heaven.{{citation needed}} Additionally, the expression "a modern Babel" may be used figuratively to describe huge projects (especially buildings or human-made structures) that fail because they are too ambitious.

The title text makes the point that even before [[Black Hat]] cut the space elevator's cable in two, it was ruined by the holes in it for the banner. The holes would reduce the surface area of the cross section of the pole, reducing its ability to keep the elevator attached to the ground. The flag and holes would also potentially make it impossible for the elevator to travel up the pole, making the entire elevator useless.

==Transcript==
:[A space elevator occupies the height of the frame, consisting of a base, a cable extending out into space, and an elevator unit with standard elevator features such as sliding doors and up/down buttons. A banner flutters in the breeze attached to the cable going up above the elevator. There is text on the banner. Text appear in four lines split across the elevator cable itself, the rhyming portions of the text is on the right side of the cable. Five individuals stand at the base of the elevator. To the left are Megan, a Cueball-like guy with his arms raised, and Ponytail, who is holding a bottle of champagne/sparkling wine which is bubbling out down the neck of the bottle. To the right is Black Hat, who cuts the cable with a pruning shear like it was part of the ceremony as a ribbon cutting. Finally further right is Cueball who sees what Black Hat is doing. He is very alarmed holding a hand to his mouth while holding the other out towards Black Hat.]

:Banner: Space Elevator
:Banner: Grand opening
::{|
|-
|style="text-align:right;"|After countless
|style="text-align:left;"|engineers
|-
|style="text-align:right;"|spend trillions over
|style="text-align:left;"|fifty years,
|-
|style="text-align:right;"|a modern babel
|style="text-align:left;"|disappears
|-
|style="text-align:right;"|because some fuck brought
|style="text-align:left;"|pruning shears.
|}
:Pruning shears: ''Snip''
:Cueball: ''!!''

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]
[[Category:Elevators]]
[[Category:Space]]
[[Category:Science]]
[[Category:Sabotage]]

601: Game Theory

2022-05-21T02:52:39Z

Ncpenguin: Undo revision 271422 by Explain xkcd server admin (talk)

{{comic
| number = 601
| date = June 24, 2009
| title = Game Theory
| image = game_theory.png
| titletext = Wait, no, that one also loses. How about a nice game of chess?
}}

==Explanation==
The comic and title text is a direct reference to the movie ''{{w|WarGames}}''.

In the movie, the {{w|Artificial intelligence}} (AI) that controls the US Nuclear Weapons is asked to play ''Global Thermonuclear War'', a real time game simulating a {{w|Nuclear warfare|nuclear attack}} scenario.

'''Spoilers''': In the movie it then takes the simulation to the real world, planning to launch a real attack on the {{w|USSR}}. In the end the AI is tricked into quickly running through several scenarios of the game, and then shuts down its planned attack as a result of what it finds out.

After analyzing all possible strategies, the AI reports: "A strange game. The only winning move is not to play. How about a nice game of chess?" Interpreted literally, this means that the computer has figured out that it will lose the game no matter how it plays, so it chooses to play chess instead (at the time of the movie, computers could not yet beat the best human chess players, so it would be more interesting). A more profound interpretation is that wars always end badly for all parties involved so it's better to play nicer games like chess.

In this comic Cueball loads an AI and then ask it to "analyze love" (equivalent to playing the "love game"), which initially could be expected to end happily for everyone involved, as love is the opposite of war and war ends always so badly. Surprisingly, the result from the AI is similar to the war games. Thus if you "play the love game", you'll end up badly, regardless which moves you play.

The title text leaves love as looking actually worse than war, since in war there's at least the "winning move" of not playing, however in love even refusing to play means that the player loses the game anyway. [[Randall]] is thus stating that you have to go after love, even though you know you will lose/get hurt sometimes, because you will for sure also lose the game, even if you pretend not to play. The AI then again suggest a game of chess, as in the movie.

==Transcript==
:[Cueball is sitting at a desk in an office chair typing on his computer. The text appearing above him is implied to be what is displayed on the screen.]
:A.I. Loaded
:>>> Analyze love

:[An hourglass appears over the computer as Cueball sits back and wait.]

:[The hourglass continues to display as Cueball shifts in his chair.]

:[A zigzag line from the computer indicates the final reply from the computer to the query.]
:Computer: A strange game. The only winning move is not to play.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Artificial Intelligence]]
[[Category:Computers]]
[[Category:Romance]]
[[Category:Chess]]
[[Category:Fiction]]

1713: 50 ccs

2022-05-21T02:52:26Z

Ncpenguin: Undo revision 270978 by Explain xkcd server admin (talk)

{{comic
| number = 1713
| date = July 29, 2016
| title = 50 ccs
| image = 50_ccs.png
| titletext = There's been a raccoon accident at an accordion bacchanalia! Double doses!
}}

==Explanation==
This comic presents a busy day in the clinic for doctor [[Ponytail]], who orders 50 ccs from a nurse (probably [[Megan]] who walks in front of her rather than [[Cueball]] walking away behind her), all the while everyone is hurrying along the hall. This could be a typical scenario in a busy hospital. However the pun is that the 50 ccs are not medicine but should be used to write "hiccup vaccine" 25 times.

In medicine, "cc" usually means "{{w|cubic centimeter}}", and is often called that by medical personnel. A cubic centimeter is equal to 1 ml (milliliter), so "50 ccs" usually means 50 ml of a certain medicine. In this case however, the doctor has not told the nurse to bring 50 ccs of any given medicine; instead, she needs to write "hi'''cc'''up va'''cc'''ine" 25 times, with both words containing the letter combination "cc", so she needs to write that combination 50 times.

That is the joke, that the 50 ccs literally means the two-lettered 'cc' fifty times.
*50 cc would be
**cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
** just enough 'cc's to spell ''hiccup vaccine'' 25 times.

There's no conventional {{w|vaccine}} against {{w|hiccup}}s. However, performing tasks meant to distract one's self is a method to stop hiccups. Therefore the act of writing "hiccup vaccine" 25 times would itself comprise one more of those hiccup cures that never seems to work. What these techniques all rely on is that they all force one to hold one's breath, thus resetting the diaphragm from its out of sync spasms. But if Ponytail has discovered a vaccine that ''does'' somehow cure or prevent hiccups, then this unexpected result is worth reporting in medical journals and seeking grants for further study. Thus, wanting to write about it 25 times is understandable!

The title text text refers to a fictional event with four words containing "cc" (ra'''cc'''oon, a'''cc'''ident, a'''cc'''ordion, ba'''cc'''hanalia), which means she needs to write "cc" 100 times. Referring to the 50 ccs from above, this would be a double dosage.

Although the words of the sentence has been chosen based on their cc's the sentence is quite interesting in itself:
*An {{w|accordion}} is a box-shaped musical instrument with tangents like on a piano. The instrument is played by compressing or expanding the bellows. It has sometimes been accused of being a [http://i47.photobucket.com/albums/f193/ZenLunatic82/FarSide-Accordion.jpg hellish instrument]. It has not been used in xkcd before.
*The ''{{w|Bacchanalia}}'' were Roman festivals of {{w|Bacchus}} (Roman name for the equivalent Greek wine God Dionysus). The festivals were based on various ecstatic elements of the Greek {{w|Dionysia}}.
*The animal {{w|raccoon}}, has begun to appear in {{w|Raccoon#Urban_raccoons|urban areas}} which has given rises to increasing {{w|Raccoon#Conflicts|conflicts with humans}}. A dead raccoon had thus found its way into Cueball's car in [[1565: Back Seat]] and already back in [[1025: Tumblr]] Megan has a raccoon sex dungeon in her attic!

So here there is talk of a wine festival with music played on accordions that has had an accident involving raccoons, in addition to the need for vaccine against the hiccups.

A similar doctor Ponytail is shown in [[883: Pain Rating]] also along with Cueball and Megan and just with Megan in [[996: Making Things Difficult]].

==Transcript==
:[Ponytail in a doctor's coat, walks right while reading from a clipboard, passing Cueball walking the other way while she talks to Megan walking in front of her.]
:Ponytail: Nurse, bring me 50 ccs!
:Ponytail: I need to write "hiccup vaccine" 25 times!

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Megan]]
[[Category:Animals]] 
[[Category:Doctor Ponytail]]
[[Category:Medicine]]

365: Slides

2022-05-21T02:52:13Z

Ncpenguin: Undo revision 271210 by Explain xkcd server admin (talk)

{{comic
| number = 365
| date = January 2, 2008
| title = Slides
| image = slides.png
| titletext = Did you know they can actually physically throw you out of SIGGRAPH?
}}

==Explanation==
In the context shown, the expression "bear with me for a moment" usually implies that two seemingly unrelated topics are in fact connected, and the connection is to be explained later. This is not the case in the comic: [[Cueball]] is in fact simply showing random slides that have no connection to each other. By using the phrase liberally and never actually explaining the links, it is suggested that a presenter can simply continue to show random slides for an extended period before anyone actually realizes what is going on.

The title text refers to {{w|SIGGRAPH}}, an annual computer graphics conference held since 1974. In [[541: TED Talk]], it is said that [[Randall]] has been banned from SIGGRAPH, and we can infer from this comic that he was physically thrown out of it. Another (very implausible) possibility is that Randall is making the joke that people who attend computer graphics conferences are stereotypically not very athletic, and therefore unlikely to be able to physically throw someone.

In addition, the fact that Cueball was attending SIGGRAPH is another joke: Neither the Quantum Hall effect, a concept in quantum mechanics, nor rainfall in the Amazon forest, have anything to do with SIGGRAPH's focus of computer graphics.

==Transcript==
:[Cueball is standing on a stage, pointing at a line graph using a pointer.]
:Cueball: That chart explained the quantum hall effect. Now, if you'll bear with me a moment, this next graph shows rainfall over the amazon basin...
:[Caption below the panel:]
:If you keep saying "bear with me for a moment" people will take a while to figure out that you're just showing them random slides.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Line graphs]]
[[Category:Public speaking]]
[[Category:Banned from conferences]]

2223: Screen Time

2022-05-21T02:51:58Z

Ncpenguin: Undo revision 271159 by Explain xkcd server admin (talk)

{{comic
| number = 2223
| date = November 1, 2019
| title = Screen Time
| image = screen_time.png
| titletext = These new Bluetooth socks are great, but it's troubling to learn that I average almost 14 hours of Shoe Time a day.
}}

==Explanation==
[[Cueball]] is reading the report from a smartphone app showing the average time each day that he was NOT looking at his phone during the hours he was awake this last week. This is a reversal of the more expected behavior for a {{w|screen time|screen-time}} app, which would normally report the amount of time spent looking at the screen. The point is that as mobile phone usage becomes more prevalent, it may be easier to comprehend to report non-screen time.

People in the US spent an average of 24 hours of non-work/education screen time per week in 2015, compared to 10 hours of active leisure, according to one estimate.[[https://www.brookings.edu/blog/social-mobility-memos/2016/09/13/how-free-time-became-screen-time/ How free time became screen time]] Averaged per day that comes to 3.4 hours screen time and 1.4 hours active leisure.

Screen time may be associated with various undesirable conditions, such as mental health difficulties like depression, decreased activity, reduced sleep quality and quantity.

In Cueball's particular case, if we assume that he is awake 17 hours a day (the average for most people in USA), then his non-screen time average of 2 hours 48 minutes means that he spent more than 84% of his awake time last week looking at a screen. This means that while his 6% improvement is positive, he still has quite a significant habit. His previous non-screen-time would have been 2 hours 38 minutes, so he has managed to shave 10 minutes off. Increased screen time often comes at the expense of decreased sleep time, so it may not be fair to assume a constant amount of sleep.<ref>[[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5279707 Digital media use in the 2 h before bedtime is associated with sleep variables in university students]]</ref><ref>[[https://www.sciencedirect.com/science/article/abs/pii/S1389945717303507 Decreases in self-reported sleep duration among U.S. adolescents 2009–2015 and association with new media screen time]]</ref>

Ironically, in order for Cueball to use the app, he has to be looking at his mobile screen. The increasing use of mobile devices in modern society has been a cause for concern, with many people arguing this leads to addiction, other health risks, or people simply not talking to each other.

The title text parodies the idea of a screen time app by describing a "shoe time" app, which would track the amount of time a person spends wearing shoes. It's unclear what the practical use for this would be, as there is little controversy about the prevalence of shoes in our society. Possibly an app that tracks the amount of time wearing ''specific'' shoes could be useful; for example, a person suffering medical problems from wearing the wrong footwear could track the amount of time they spend wearing particular shoes, and correlate this with their health to figure out which ones are causing problems.

Possibly, the point being made is that use of phones have become so constant in our lives that using them for many hours a day is as unremarkable as using shoes for many hours a day. Or, since it's the socks that are Bluetooth-enabled, they may be reporting negatively about almost constant obstruction by shoes, whereas the socks would prefer to report a much lower "Shoe Time" score.

Some cultures have the custom of taking shoes off when in the house, so those people would boast lower (and presumably more favorable) "Shoe Time" scores. It may also be a reference to the "{{w|shoe phone}}" on the television show ''{{w|Get Smart}}''. (If {{w|Maxwell Smart}} wore these socks, they could track his phone usage, because his phone was in his shoe).

==Transcript==
:[Cueball is looking down at his phone. The text is what he reads on the screen, as shown by a zigzag line emanating from a starburst at the top of the phone.]
:Phone: Screen time report:
:Phone: While awake, you averaged 2H 48M per day looking at things other than your phone. That's up 6% from last week!

:[Caption below the panel]
:At some point, it starts making more sense to track '''''non'''''-screen time.

{{comic discussion}}

[[Category: Comics featuring Cueball]]
[[Category:Smartphones]]
[[Category:Screen Time]]

1924: Solar Panels

2022-05-21T02:51:45Z

Ncpenguin: Undo revision 270973 by Explain xkcd server admin (talk)

{{comic
| number = 1924
| date = December 4, 2017
| title = Solar Panels
| image = solar_panels.png
| titletext = This works for a surprising range of sunlit things, including rooftops (sure), highway surfaces (probably not), sailboats (maybe), and jets, cars, and wild deer (haha good luck).
}}

==Explanation==

This handy decision tree aims to help in finding out whether a given object should have {{w|solar panel}}s installed on it.

The root question is whether the object of choice moves. If it doesn't and has no nearby empty space that would be more practical for the solar panel installation, then yes, the object should be equipped with the solar panels. If the object is static, but you could more easily install the panels somewhere else nearby, probably that's the best place. An example of this is a slanted rooftop of a house or a field on a hillside: it's certainly possible to put solar panels there, but if a flat surface, like a flat-roofed house or a level field, is available, it would generally be easier to put them on that. This way, you can select the optimal direction for the panels to face, which might not be possible on a given incline, or even have them [https://www.linak.com/business-areas/energy move to track the sun]. However, if the house has a side that is turned towards the sun (south in the Northern hemisphere) then a house roof could be even better than on the ground, which is why the title text says "sure" for rooftops. For another example of things where "putting next to it" instead of "on it" is generally the easier (and arguably better) option, see the "highway surfaces" of the title text.

If the object moves, the next question is whether its batteries can be recharged or swapped with ease, in which case batteries may be a better option than solar panels, if the purpose of the panels is to power the object. The idea is that solar panels on a vehicle sound like an interesting idea, but batteries can be much more easily (and economically) recharged from a fixed electrical station than using solar panels on the vehicle as a power source. It may be possible to have solar panels ''on the electrical station'', but that is a separate device to consult the table on.

Finally, if the object moves and batteries are not an option, the last question is whether the object heats up during operation. If so, solar panels may not work well. [[Randall]] doubts it mockingly, see also the title text regarding his ''Haha Good luck'' final option.
Solar panels can only produce electrical power equal to about 20% of the solar radiation they receive. Thus, a device that heats up during use likely consumes much more power than the amount which could be produced by solar panels covering its surface - so "good luck". Obviously, many animals are also "moving objects" fitting this condition, and installing solar panels on them is bound to be a challenge.
Moreover, solar panels do not work effectively when excessively hot [http://news.energysage.com/solar-panel-temperature-overheating/] (solar panels are typically designed to operate in temperature ranges of 15-25 Celsius, 59-77 Fahrenheit, 288.15-298.15 Kelvin, 518.67-536.67 Rankine, 12-20 Réaumur, 15.38-20.63 Rømer, 127.5-112.5 Delisle, 4.95-8.25 Newton, 5.968 546×10⁻²¹ - 6.174 608×10⁻²¹ [[2292: Thermometer|joules of translational kinetic energy]] or 37-51 [[1923: Felsius|Felsius]]).

But if changing batteries is not an option, and heat production and power requirements are low, then solar panels can be an excellent solution on a moving object. An excellent case for this is on [[:Category:Space probes|space probes]] and satellites, which are typically powered entirely by solar panels (and reliably receive sunlight, because there are no clouds to interfere). Randall is well aware of this, as shown with the comics [[695: Spirit]] and [[1504: Opportunity]] about the two solar-powered [[:Category:Mars rovers|Mars rovers]], although in this comic he seems to have only been concerned with Earthbound objects.

The flow chart, however, does not mention if the thing in question actually ''needs'' solar panels, but according to the title text it works very well, and thus Randall implies that if the answer is ''sure'' then it is relevant to put solar panels there. The more solar panels in place, the fewer fossil fuels are needed, and this is in line with Randall's general interest in reducing [[:Category:Climate change|climate change]].

The title text suggests that this flow chart is very broadly applicable to anything the Sun hits.

Rooftops are classed as "sure", and those are, indeed, an active subject of solar installation (though, if there's suitable land nearby, it might not be the most efficient).

Highway surfaces are classed as "probably not". There have been proposals and experiments a concerning {{w|photovoltaic pavement covering roadways with solar panels}}, but these have proven to be impractically expensive and prone to damage. The flow chart suggests that, since many highways are near land that could be used for solar panels, that will usually be the more viable option.

Sailboats are classed as "maybe". Unlike boats with motors, sailboats don't consume enough power to heat up, only requiring enough power to provide electricity for whatever equipment and appliances are on board. Since some sailboats are at sea long enough that swapping or recharging batteries may be difficult, solar panels could be a viable option.

Multiple other moving objects, including jets, cars, and wild deer ends up on the ''haha good luck'' result. While these examples seem unrelated, they all have the same limitation: they consume far more power while moving than could realistically be harnessed from solar panels (as demonstrated by the fact that they noticeably heat up). There are some experimental solar-powered cars, but these tend to be exceptionally low power (and resultingly low-performance) vehicles. Wild deer are clearly a humorous option, as they'd have little use for the electricity from solar panels, and would likely resist any efforts to install them. Nonetheless, Randall includes them to make the point that the chart is effective, even with ridiculous examples.

==Transcript==

:[A flow chart that features four questions in bubbles. Each question has yes/no options in bubbles overlain to the left and right on the question bubble. Curved arrows points from the yes and no bubbles to either the next question or the result. The result written at the bottom is not inside bubbles. The chart has two main branches, that ends up in five places using only four different results, as the middle result is shared by both branches. Above the chart, there is a caption:]
:'''Should I put solar panels on it?'''

:Does it move around?
::Yes
:::Does it have regular chances to recharge or swap batteries?
::::Yes
:::::Probably not
::::No
:::::When running, is it hot to the touch?
::::::No
:::::::Maybe
::::::Yes
:::::::Haha good luck
::No
:::Is there an empty space nearby where it would be easier to put them?
::::Yes
:::::Probably not [Uses the same sentence as the one in the first branch.]
::::No
:::::Sure

{{comic discussion}}

[[Category:Flowcharts]]
[[Category:Animals]]
[[Category:Solar power]]

1304: Glass Trolling

2022-05-21T02:51:33Z

Ncpenguin: Undo revision 271072 by Explain xkcd server admin (talk)

{{comic
| number = 1304
| date = December 16, 2013
| title = Glass Trolling
| image = glass_trolling.png
| titletext = Plus, when someone finally grabs your glasses and stomps on them, it costs way less than $1,500 to replace them.
}}

==Explanation==
This is another strip in the [[My Hobby]] series.

{{w|Google Glass}} is a set of glasses frames worn like typical glasses that features an optical display and internet connectivity. It responds to voice commands starting with [https://support.google.com/glass/answer/3079305 "OK ''glass''"], for example to initiate video recording or to check tomorrow's weather. Strangers and other people surrounding the user would often find it annoying to hear someone talking to "himself", or to ''Glass''. Also many people who buy the newest gadgets, like Google Glass, like to brag about it, and thus would try to say ''OK Glass'' so loud that other people will notice they have these cool new glasses. This can be very annoying in general!

[[Randall|Randall's]] hobby, is saying "OK, ''glass''" before any sentence while he is only wearing regular glasses. Like here where he (drawn as usual like [[Cueball]], with regular glasses) is checking tomorrow's weather, not on the glasses but on his {{w|smartphone}}. Apparently this is even more annoying to the bystander than if he would actually wear a real ''Google Glass'' while saying so. He thus both annoys other people, mocks people who buy such glasses to brag about them, and in general mocks Google Glass.

In the title text, Randall states that there is an extra benefit by doing this while only wearing regular glasses. Because when someone is finally fed up with the annoyance and rips the glasses off and stomps on them, then it would cost much less for regular glasses than if he had to replace a "Google Glass". These are very expensive - $1,500 at the time of this comic, as the title text says. (Note that regular glasses can also be very expensive, but you could choose to wear your reserve glasses for such a prank...). Also [https://mashable.com/2014/02/26/google-glass-assault/ several people] have claimed to been attacked while wearing Google Glass in San Francisco, with one person claiming [https://mashable.com/2014/04/13/google-glass-wearer-attacked/ their attacker destroyed their Glass].

The "OK, ''Glass''" keyword is not useless outside of ''Glass''; in the browser Chrome and the Android/iOS app ''Google Now'', "OK, ''Glass''" is also valid instead of "OK, ''Google''" to initiate a voice command. While Cueball may be using this app, it is not necessarily the case, given that the caption states that Cueball enjoys prefacing everything with the phrase.

It seems generally that Randall is no fan of Google Glass, which was also shown earlier in [[1251: Anti-Glass]].

==Transcript==
:[Caption above the panel:]
:My Hobby:

:[Cueball, wearing regular glasses, is holding his smartphone up in one hand while typing, as shown with two times two small movement lines on either side of the phone. A voice from off-panel right emanates from a starburst at the frame.]
:Cueball: OK, Glass, check tomorrow's weather.
:Cueball: Ooh, snow!
:Off-panel voice: Oh my god, it's somehow even ''more'' annoying than if you had it.

:[Caption below the panel:]
:Saying "OK, Glass" before everything while wearing regular glasses.

==Trivia==
Google Glass was a [[:Category:Google Glass|recurring theme]] in xkcd in 2013.

{{comic discussion}}

[[Category:My Hobby]]
[[Category:Comics featuring Cueball]]
[[Category:Smartphones]]
[[Category:Google Glass]]
[[Category:Weather]]

1124: Law of Drama

2022-05-21T02:51:03Z

Ncpenguin: Undo revision 271395 by Explain xkcd server admin (talk)

{{comic
| number = 1124
| date = October 22, 2012
| title = Law of Drama
| image = law of drama.png
| titletext = 'Drama' is just 'people being upset,' when someone says they're always surrounded by drama and they just ignore it, it starts to make sense that their strategy might be backfiring.
}}

==Explanation==
The comic comments on how often people who label themselves as an innocent party in a debate are often far from it. Essentially, [[Randall]] seems to be graphically stating that people who claim to hate and want to avoid drama are invariably associated with it. Since [[552: Correlation|correlation does not imply causation]], it might be a leap — at least scientifically speaking — to actually surmise that they're the cause of it.

The title text suggests that the person's attitude towards drama is wrong. Supposing that "'Drama' is just 'people being upset'", then ignoring drama is a very bad way to deal with it. By ignoring people's problems, you certainly won't be able to help them, and are at risk of causing further problems through ignorance.

==Transcript==
:[A Cartesian graph labeled 'How often someone declares that they hate "drama" and always avoid it' on the x-axis and 'Rate at which they create drama' labeled on the y-axis. The graph is a slightly exponential curve sloping upwards.]

{{comic discussion}}

[[Category:Line graphs]]
[[Category:Psychology]]

1534: Beer

2022-05-21T02:50:41Z

Ncpenguin: Undo revision 272193 by Explain xkcd server admin (talk)

{{comic
| number = 1534
| date = June 5, 2015
| title = Beer
| image = beer.png
| titletext = Mmmm, this is such a positive experience! I feel no social pressure to enjoy it at all!
}}

==Explanation==
[[Hairy]] offers [[Cueball]] some {{w|beer}} from his fridge, and Cueball takes the opportunity to suggest that people should admit that beer tastes bad and stop pretending to like it. Hairy berates Cueball for making such an affirmation, and Cueball admits defeat, deciding to drink the beer anyway and pretend to like it to play his part in what he perceives to be a mass delusion.

There are two possible interpretations of this comic. One is that Cueball is right and that no one really likes beer, and everyone is just pretending in order to fit in. The other is that Hairy actually likes beer, but Cueball fails to recognize that possibility, assumes Hairy is faking it, and plays along.

In the case where Cueball is correct, the comic would imply that beer doesn't actually taste good, and people instead pretend to like beer to conform to social norms. The theory is that this pretense is perpetuated by advertising and {{w|peer pressure}}, which present beer as a naturally pleasant beverage. In this interpretation, Cueball, having failed to break the [https://www.youtube.com/watch?v=5S1d3cNge24&t=47m34s mutual knowledge barrier], admits defeat and joins Hairy in pretending to enjoy beer.

The second case would mean that Cueball mistaken in assuming that nobody likes beer, either because he fails to {{w|empathy|empathize}} with those who have a different experience than his, or because he's heard from other people who also admitted not to like beer, and extrapolated that opinion to everyone (perhaps assuming that such admissions are underrepresented due to the {{w|Drinking culture|cultural bias in favor of drinking}}).

The title text expands on Cueball's perspective, stating ({{w|sarcastic|sarcastically}}) that he feels no peer pressure to like beer. The pressure to drink beer or other alcoholic drinks is a well-known phenomenon, especially among {{w|Peer pressure#Substance use and adolescents|adolescents and young adults}}.

==Transcript==
:[Cueball and Hairy standing in front of a fridge.]
:Hairy: What do you drink? Stouts? Lagers?
:Cueball: Uh, anything's fine.

:[Cueball and Hairy holding beers and Hairy is drinking.]
:Cueball: ...do you ever think maybe we should just admit that all beer tastes kind of bad and everyone's just pretending?

:[Now Cueball drinks.]
:Hairy: Man, you are ''no'' fun at all.
:Cueball: Ok, got it. Not a word.
:Hairy: Dude, if you don't like it, don't drink it.
:Cueball: No, no, gotta do my part! Mmmmm!!!

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Hairy]]
[[Category:Sarcasm]]
[[Category:Food]]

1497: New Products

2022-05-21T02:50:26Z

Ncpenguin: Undo revision 272046 by Explain xkcd server admin (talk)

{{comic
| number = 1497
| date = March 11, 2015
| title = New Products
| image = new products.png
| titletext = If you ever hear "Wait, is that Kim Dotcom's new project? I'm really excited about it and already signed up, although I'm a little nervous about whether everyone should hand over control of their medical...", it's time to dig a bunker in your backyard.
}}
==Explanation==
This comic points out an apparent paradox in product performance: Many products that are [https://www.google.com/search?q=No+wireless+Less+space+than+a+nomad+Lame criticized by techies when first announced] go on to great success, and many that are heavily hyped are total flops. The product in question may be a reference to the {{w|Apple Watch}}, which was announced around the time of this comic's release.

{| class="wikitable"
! If they say...
! It means...
! Explanation
! Example
|-
|"It doesn't do anything new"
|rowspan="2"|The product will be a gigantic success.
|A product that "doesn't do anything new" may still be successful for a variety of reasons. It may in fact do something new that the engineers and programmers are overlooking, or it may simply be a better presentation of an older idea that so far hasn't caught on among the general public. This latter category is the completion of the life-cycle mentioned later in the comic, those products whose "ideas will show up in something successful."
|{{w|iPod}}, {{w|iPad}}
|-
|"Why would anyone want that?"
|If engineers and programmers can't figure out why anyone would want a product, it may be because the applications are highly avant-garde or niche (though that could make it hard for the product to be a mass success). Alternatively, engineers and programmers themselves often don't share the tastes and priorities of non-technical people, and are therefore unable to understand and accurately assess the appeal that a product will have to the masses.
|{{w|Twitter}}, {{w|MacBook Air}}
|-
|"Really exciting"
|rowspan="2"|The product will be a flop. Years later, its ideas will show up in something successful.
|rowspan="2"|Products that are "really exciting" to engineers and programmers, so much so that they have already pre-ordered them, may fail to succeed for various reasons, such as:
*The product is excellent, but costs too much for mass audiences.
*The product has an unintuitive interface or strange aesthetics, which techies are willing to "live with", but regular people are not.
*The product has bad marketing; the masses never "get" how good the product is.
*The product turns out to be "nerd bait" or {{w|vaporware}}, offering visionary ideas that aren't actually feasible yet.
When a later product is based on the same ideas, but without the mistakes, it will be worth billions. Then the techies will say "it doesn't do anything new".
|{{w|NeXT}}
|-
|"I've already preordered one"
|[http://arstechnica.com/gadgets/2014/07/how-one-kickstarter-project-squandered-3-5-million/ myIDkey]
{{w|Ubuntu Edge}}
|-
|"Wait, are you talking about <unfamiliar person's name>'s new project?"
|The product could be a scam and may result in arrests or lawsuits.
|If a product's developer's name is well-known among engineers and programmers, but not among the general public, that's usually not a good sign. Quite likely, the developer is someone who goes a step further than those in the previous category, not just announcing something cool and exciting they can't follow through on, but doing so ''knowing'' that they can't follow through yet still taking people's money. The state may press criminal charges against them (for fraud or such), or the angry investors may sue to get their money back.
|{{w|Shawn Fanning}}
|-
|"I would never put <company> in charge of managing my <whatever>"
|Within five years, they will.
|If engineers' and programmers' only objection is that they don't like the company behind the product, that's basically a tacit admission that there's nothing else wrong with it. For the average consumer, the perks of a groundbreaking new product outweigh whatever problems they may have with the company behind it. This category also relates to the numerous privacy concerns raised about the devices and software of certain companies, and the way people tend to get riled up about these issues and then forget about them once it becomes too inconvenient. For instance, a few months ago, in the aftermath of Facebook releasing its Messenger app, it would not be uncommon to hear people say "I would never put Facebook in charge of managing my network connectivity/phone calls/camera". However, 6 months later and barely anyone is complaining anymore, and within another year or so even the most hardline of privacy advocates will probably give in.
|[https://www.google.com/search?q=apple+OR+google+OR+microsoft+OR+amazon+OR+facebook+"is+evil" take your pick]
|}

The title text imagines a product that fits into the second, third and fourth categories:
* "Wait, is that Kim Dotcom's new project?" — third category
* "I'm really excited about it and already signed up." — both options from the second category
* "Although I'm a little nervous about whether everyone should hand over control of their medical..." — fourth category

{{w|Kim Dotcom}} is a controversial entrepreneur and [http://www.ibtimes.co.uk/who-kim-dotcom-timeline-his-life-1442384 convicted fraud]. He {{w|Kim Dotcom#Personal life|changed his surname}} to "Dotcom" because of the {{w|Dot-com bubble|dot-com stock market bubble}} that made him a millionaire. He fits perfectly into the mold of someone well-known to programmers and engineers (as well as New Zealanders), but perhaps not so much to your average Joe.

Taken together, these imply that an untrustworthy and potentially malicious company has an exciting new idea that may eventually come out in successful form, gains control of a large amount of medical information, but ultimately result in lawsuits not just from investors but from misled consumers (category 3). Because the initial release will be a flop (category 2), there is some time to prepare before the successful use of this idea becomes a reality (also category 2), at which point that or some other company will gain control of a large amount of people's medical something (category 4). Once this happens you could expect dramatic repercussions; this is why the title text suggests to dig a bunker while there is still time.

==Transcript==
:'''Predicting the success or failure of a new product'''
:based on what engineers and programmers are saying about it

:[A two-column table illustrating this. The headings are actually standing above the table.]
:{| class="wikitable alternance"
! If they say...
! It means...
|-
| "It doesn't do anything new"
|rowspan="2"|The product will be 
a gigantic success.
|-
| "Why would anyone want that?"
|-
| "Really exciting"
|rowspan="2"| The product will be a flop. 
Years later, its ideas will 
show up in something successful.
|-
|"I've already preorded one"
|-
| "Wait, are you talking about 
<unfamiliar person's name>'s 
new project?"
| The product could be 
a scam and may result 
in arrests or lawsuits.
|-
| "I would never put 
<company> in charge of 
managing my <whatever>."
| Within five years, they will.
|}

==Trivia==
*There is a spelling mistake in the comic: "preorded" should have been "preordered".

{{comic discussion}}
[[Category:Charts]]
[[Category:Comics featuring real people‏‎]]
[[Category:Programming]]

573: Parental Trolling

2022-05-21T02:47:55Z

Ncpenguin: Undo revision 271245 by Explain xkcd server admin (talk)

{{comic
| number = 573
| date = April 24, 2009
| title = Parental Trolling
| image = parental trolling.png
| titletext = They'll pick music and culture that they know annoys you. Building in behavioral easter eggs is a fair retaliation!
}}

==Explanation==
Set in the future, a daughter approaches her father playing a music video of {{w|Rick Astley}}'s "{{w|Never Gonna Give You Up}}". The daughter insults her father's generation's versions of playing pranks, specifically {{w|Rickrolling}}. The daughter refers to this as "{{w|trolling}}" (part of the comics title), which is popular jargon for trying to disrupt a person or community via an action to elicit an emotional response. She then comments that Cueball's generation's trolling efforts suck.

The humour is in that the dad reveals he has 'trolled' his daughter by creating a reaction in which her speech centers would shut down when she gets upset, thus eliciting an emotional response which perfectly displays his prank. This would not be possible in real life unless he messed with her brain, which would be dangerous and possibly illegal.<ref>https://medlineplus.gov/ency/article/003018.htm</ref> This could also be referring to how most people tend to get confused in their speech patterns when upset, meaning that the dad '''could''' in fact be trolling his daughter through her misunderstanding.

In this comic, the girl holds an ultra-thin tablet, a futuristic technology when this comic was released, a year before the release of the iPad. It also shows a curved computer monitor and keyboard, both of which seem to float above the desk.

The title text refers to the conflict between teenagers and adults over music and culture, with teenagers often listening to music which annoys their parents. '{{w|Easter egg (interaction design)|Easter egg}}' is a term used to describe a hidden inside joke or feature inside software. Here, the daughter has been treated like a piece of software by her father Cueball. He states that since the kids on purpose chooses music and culture that they know annoys their parents, it is a fair retaliation to build in such Easter egg responses. Many people would probably disagree on this, but maybe not so much parents with teenagers at home.

==Transcript==
:[In a frame crossing the top border of the first panel of the comic:]
:The future

:[Cueball is sitting at a futuristic desktop computer with the curved screen and keyboard both floating above the table, and a girl with pigtails is standing behind him with a portable ultra-thin screen. She shows the screen to Cueball. On it is a man with dark hair.]
:Girl: Hey dad, look at this old music video.
:Video: We're no strangers to love...
:Cueball: Wow, you got me.

:[The girl now looks at the device.]
:Girl: Did your generation really use this to troll people? ''So'' lame. You know, you guys '''sucked''' at pranks.

:[The girl is holding the device down along her legs as Cueball turns from his computer and addresses her.]
:Cueball: Did we? I once raised a kid with conditioning so her speech centers shut down when she was upset.

:[The girl has dropped the device on the floor and is fisting her hands. Cueball has turned back and is typing on the keyboard.]
:Girl: What? No, you couldn't have bleegle warble yargle arrgh!
:Cueball: Teehee.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Internet]]
[[Category:Rickrolling]]

231: Cat Proximity

2022-05-21T02:46:51Z

Ncpenguin: Undo revision 271534 by Explain xkcd server admin (talk)

{{comic
| number =231
| date =March 5, 2007
| title =Cat Proximity
| image =cat_proximity.png
| titletext =Yes you are! And you're sitting there! Hi, kitty!
}}

==Explanation==
This comic refers to the use of "{{w|baby talk}}" when speaking to pets, especially {{w|cats}}. A person's voice becomes {{w|falsetto}} and {{Wiktionary|cooing}}, vocabulary becomes simplified, and phrases are repeated, such as "Here, kitty, kitty, kitty."

The chart shows that a person's apparent intelligence decreases, and that the {{Wiktionary|inanity}} (i.e. uselessness or emptiness) of their statements increases, the closer they get to a cat.
Most people act like this when they're playing with cats or trying to call them over to them.
Thankfully, being close to a cat doesn't actually cause any decrease of intelligence in normal circumstances; the graph technically refers to ''demonstrated'' intelligence rather than actual IQ levels.{{Citation needed}}

The title text continues [[Cueball|Cueball's]] obvious statement (and thus inane/useless point made) from below the graph.

In [[1535: Words for Pets]], [[Randall]] again mentions how people often talk strangely to their pets.

==Transcript==
:[A graph with the x-axis labeled, and the scale indicated from left to right:]
:Far
:Human proximity to cat
:Near
:[Two curves are drawn and labeled, first the one starting on top, which then veers downwards and crosses the other as that curve veers upwards.]
:Intelligence
:Inanity of statements

:[Below the graph, Cueball is seen standing at three distances from a cat that is drawn to the far right. The two first Cueballs are just standing, one below far, the other in the middle, and the last is standing close to the cat (below near) with his hands up, and he is speaking.]
:Cueball: You're a kitty!

==Trivia==
*This comic is available as a signed print in the [https://store.xkcd.com/products/signed-prints xkcd store].
*If you type cat in [[UniXKCD]] it will print You're a kitty, a reference to Cueball's line in the comic.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Cats]]
[[Category:Line graphs]]
[[Category:Comics with xkcd store products]]

1683: Digital Data

2022-05-21T02:46:28Z

Ncpenguin: Undo revision 272083 by Explain xkcd server admin (talk)

{{comic
| number = 1683
| date = May 20, 2016
| title = Digital Data
| image = digital_data.png
| titletext = â€&oelig;If you can read this, congratulationsâ€”the archive youâ€™re using still knows about the mouseover textâ€!
}}

==Explanation==
{{w|Digital information}} has the potential to be copied such that the copy is 100% identical to the original. While physical media themselves (such as books, or hard drives) and information stored by analog means may degrade as the universe continues, digital information as expressed by specific values, such as combinations of binary zeros and ones, does not decay over time and can be copied indefinitely with no changes.

However, in this comic, [[Randall]] points out that while digital information itself doesn't need to degrade, things that are on the Internet are often degraded through copying when the copy is not a 1:1 copy or changes are deliberately introduced. In addition, as technology advances, the method to save or call the information changes and the medium to view it changes, occasionally causing misinterpreted information. (This is also demonstrated with the title text.) As the frames continue, they gain the appearance of images which have been screenshotted repeatedly, with a resulting loss of quality due to compression of the original resolution and {{w|JPEG}} {{w|compression artifact|artifacting}}. (The JPEG format is intended for representing photorealistic grayscale or color images; when misused for line drawings, such as comic strips, any compression artifacts become particularly noticeable, as the background is normally of completely uniform color.) In the last frame, this is taken to an extreme, as the frame appears to have been very sloppily screenshotted off of at least two different smartphones (not the same device that uses the bottom frame in the third panel as the top border in panel four), and the final image is covered both with a watermark from an unregistered screenshot program, as well as references to at least two different web sites: {{w|9GAG}} (bottom right image) and {{w|Tumblr}} in the web address bottom left. 9GAG is an online platform and social media website where users upload and share content of their own, or of other networks. It is often accused of rehosting other sites' funny content without attribution and adding their own watermark to the image or video.


As an easter egg, the [http://imgs.xkcd.com/comics/digital_data_2x.png high-resolution] (pixel-doubled) version of the comic is merely the comic resized to 50% and then to 400%, making it an image of poorer quality rather than a higher resolution image as for other comics, demonstrating how repeated {{w|image scaling}} can also introduce artifacts into images.

The title text is seemingly addressed to a reader in the future who will only be able to access xkcd through a {{w|digital archive}}. Digital information might not degrade with time, but it can't be properly displayed without knowledge of the encoding. As new encodings and file formats get developed and old ones abandoned, the webpage format of the comic might not be available in the future, when users would need special archives to view content from today's world. The title text contains seemingly {{w|mojibake|garbage characters}}, which typically result from data being interpreted according to a {{w|character encoding}} different from the one used to encode it. In this case, the characters are the result of encoding the string <tt>“If you can read this, congratulations—the archive you’re using still knows about the mouseover text”!</tt> using {{w|UTF-8}} (which represents non-{{w|ASCII}} {{w|Unicode}} characters as multibyte sequences) and then interpreting the resulting bytes as the still commonly used {{w|Windows-1252}} encoding (which uses only one byte per character, but utilizes the non-ASCII codepoints for a limited selection of extra letters and symbols such as "â" or "€"). This shows that degradation of digital data through conversions isn't restricted to images. Furthermore, as screen navigation moves away from the mouse toward touch, voice recognition, and modes still to be implemented, mouseover text will itself become archaic.

==Transcript==
:[Cueball and a White Hat are walking, Cueball holds both hands in front of him palms up.]
:Cueball: The great thing about digital data is that it never degrades.

:[They walk on in the next panel which shows jpeg compression artifacts, as if the image had been converted from png format to a lossy jpeg format.]
:Cueball: Hard drives fail, of course, but their bits can be copied forever without loss.

:[They continue walking in the third panel which is now clearly pixelated, the white is slightly discolored, and it contains part of the interface of some program, probably supposed to be a screen shot from a smartphone. At the bottom there are three blue buttons and one gray. the first is a blue "<" indicating back in a browser. Then a grayed out ">" that is not active. And then three more standard buttons in blue to the right of those two. The interface matches that of an iPhone running Safari in iOS 9 (or other versions with the same Safari UI (probably iOS 7-9))]
:Cueball: Film degrades, paint cracks, but a copy of a century-old data file is identical to the original.

:[Still walking, now Cueball holds out both arms to the sides, and finally White Hat replies. This panel is heavily pixelated and discolored and has a distorted aspect ratio. It contains a clear watermark of 9GAG (although difficult to read all letters in the end of the first word), even more 'frame' elements, and text above the image at the bottom (where the last letter is obscured by the frame of the image). There is also an internet address at the bottom left, but it is not readable except for the .tumblr.com ending. In this panel it is clear that it is a screen shot from a smart phone. The frame around the image obscure the very top of Cueball's text and the half of the last letter in White Hat's reply.]
:Cueball: If humanity has a permanent record, we are the first generation in it.
:White Hat: Amazing

:Watermark: Screenshotpro 2
:Watermark: ~Unregistered~

:Top border: Verizon LTE '''4:45 PM'''
:Bottom text [slightly cut off]: 9GAG
:Internet address at the bottom [nearly unintelligible]: [ama].tumblr.com

{{comic discussion}}
[[Category:Comics with color]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Computers]]
[[Category:Self-reference]]

1685: Patch

2022-05-21T02:45:45Z

Ncpenguin: Undo revision 271235 by Explain xkcd server admin (talk)

{{comic
| number = 1685
| date = May 25, 2016
| title = Patch
| image = patch.png
| titletext = My optimizer uses content-aware inpainting to fill in all the wasted whitespace in the code, repeating the process until it compiles.
}}

==Explanation==
{{w|Adobe Photoshop}} is a commonly used application for image manipulation. One of its features is the Patch tool, which allows the user to overwrite parts of the image, replacing them with a copy of another area of the same image. It is often used for “patching up” photographs by overwriting scratches or other visible damage to the photo. Another of Photoshop’s features is “content-aware fill”, which could also be described as “content-aware inpainting”. It works similarly to the Patch tool, but automatically generates a replacement texture from the area surrounding the deleted part instead of copying a user-specified area exactly.

{{w|GNU}} {{w|Patch (Unix)|patch}} is a program that replaces only parts of code with an updated version, without requiring the user to download the entire source code. Here, it appears the author was told to “patch” the code but used Photoshop to do this instead of GNU patch, with devastating results. Although the title text suggests that if you did this enough times the code would eventually compile, this would never happen. In fact, Photoshop could only edit an image of the text and not the text itself. However, it could work if optical character recognition (OCR) were integrated into the workflow as well.

The comic blurs the difference between {{w|text_file|text}} (in which letters and symbols represent discrete values, such as 65 being the number for the letter A in the ASCII encoding standard, and it's relatively easy for a program compiler to interpret combinations of these values as keywords and other programming constructs) and {{w|Raster_graphics|graphics}} (where the letters and symbols in the comic are actually represented by a pattern of colored dots), playing with the idea that the ''patch'' metaphor can be used on both (although with different meanings). There are common and straightforward processes for converting text information to images, such as printing, which can convert text to a graphics format very faithfully. The reverse, however, requires the use of {{w|optical character recognition}} (OCR), which attempts to figure out which letter or symbol certain patterns of dots "look like". OCR could be effective in converting some of the image in the comic back to usable text; however, it would fail on some of those patterns that have been mangled and don't look like any existing characters or symbols. A compiler can only operate on text data, so converting the graphic back into text would be a requirement to even begin to attempt to compile it, a step omitted in the title text.

The code appears to be written in {{w|Python_(programming_language)|Python}}, a programming language often referred to in xkcd, such as in [[353: Python]]. A few of the function names that can be recognized are "isPrime" and "quicksort", both elementary programming algorithms. It was also apparently originally edited using a Python-aware programming text editor, which is able to use different colors for different programming elements. For example, it appears to use red for keywords, blue for variables, and black for other elements; however, because of the mangling from the use of the wrong patching program, that doesn't appear to be consistent. Since the patching replaced graphical elements rather than whole characters, there are examples of symbols that are combinations of two different characters, and when the original two characters were rendered in different colors the resulting non-character could be in two colors, or the resulting "word" might be rendered in multiple colors.

The comic brings to attention the high rate of Adobe Photoshop piracy. GNU Patch is available for free, even [http://gnuwin32.sourceforge.net/packages/patch.htm for Windows], and Mac OS X. So the comic implies that Adobe Photoshop, a subscription to which costs $20/month, is more available than GNU patch. According to [http://blog.epicedits.com/2008/03/28/60-of-photoshop-users-are-pirates/ this poll], 58% of Photoshop copies were pirated.

The title text also explains that the patch used the content-aware inpainting to fill in all the wasted whitespace in the code. In most programming languages, whitespace is necessary to separate words, so this would combine words that shouldn’t be combined and create invalid code. Since the code in the image is Python, the code will be messed up even more, because Python uses whitespace as a part of its programming syntax. For example, statements are separated by newlines instead of by semicolons (;), and indentation is used instead of brackets to determine the scope of each section of code.

The original code was likely as follows:

import re
def isPrime(n):
if n<=1:
return False
for i in range(2, int(n**0.5)+1):
if n%i==0:
return False
return True
def isPrimeRegex(n):
if re.match(r'^1?$|^(11+?)\1+$', '1'*n):
return False
return True
def quicksort(a):
if len(a) < 2:
return a
pivot=a[0]
l=[i for i in a if i<pivot]
r=[i for i in a if i>pivot]
mid=[pivot]*(len(a)-(len(l)+len(r)))
return quicksort(l)+mid+quicksort(r)

isPrime and quicksort are standard python implementations of simple algorithms (although you would not generally write a sorting algorithm in python as there are built-in algorithms available). isPrimeRegex uses the [https://docs.python.org/library/re.html re module] to detect if a number is prime by seeing if a string containing that many 1s can be matched to 2 or more copies of some string containing at least 2 1s.

The comic two comics back [[1683: Digital Data]], also related to turning digital data into bad copies. Less than a month before quicksort was mentioned in [[1667: Algorithms]], and a month before that another "easy" solution to a programming problem was released in [[1654: Universal Install Script]].

Using a Photoshop tool for a task it is not intended for was also used in [[1784: Bad Map Projection: Liquid Resize]], where [https://helpx.adobe.com/photoshop/using/content-aware-scaling.html Photoshop's content-aware resizing tool] was a very questionable choice to use for a Map Projection.

==Transcript==
:[The panel displays part of a code, in five different colors (red, purple, light blue, blue, and green) as well as normal black text, which due to image editing is difficult to read. The first and last lines are partly obscured by the frame of the panel. Here below is an attempt to transcribe the code, using the sign "¤" for anything not easily transcribed. Feel free to add other signs instead of these that look more like the one in the image (and also improve the attempted transcription if possible).]
impoɞtme
dooPisPŞ¤me(n):
r(¤n<n,1:
retern F(ise
for i irararre(2, nint *n**n+5)+5):
if n i==0
ret¤¤nrselsel:
re¤ irn True
defesisPrimcieg ¤x(cx
if ge¤inatcx(ᵣ'^(1?| ?.1+?)\+)$'*n )1'*n):
rerjrn Fa( e
LetylnrTrl
dql qlsorsorn(a :
if ¤n(a < 2:
eteturn a
pi= =r fa[0]
l=pi=for j ın a i< i<pi<(t]()
r=[ı=for f in a) r i>viviv](vo)
mid=[pi[*t]*(l*t,(a)-(lenpienlen(c)))
r¤lrurrriklcksckt(l) + r ¤ ¤quickrort(r)

:[Caption below the panel:]
:Protip: If you don't have access to the GNU ''patch'' tool, you can use the Photoshop one.

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

1395: Power Cord

2022-05-21T02:45:22Z

Ncpenguin: Undo revision 272149 by Explain xkcd server admin (talk)

1289: Simple Answers

2022-05-21T02:45:02Z

Ncpenguin: Undo revision 271075 by Explain xkcd server admin (talk)

{{comic
| number = 1289
| date = November 11, 2013
| title = Simple Answers
| image = simple answers.png
| titletext = 'Will [ ] allow us to better understand each other and thus make war undesirable?' is one that pops up whenever we invent a new communication medium.
}}

==Explanation==
This is [[Randall]]'s commentary on some of the baseless skepticism and equally baseless optimism directed at new technologies. Related: [[1215: Insight]] and [[1227: The Pace of Modern Life]]. While it's always healthy to evaluate the advantages and disadvantages of cutting-edge tech before blindly diving in and adopting it, it's not healthy to base that evaluation on unrealistically high standards and expectations.{{Citation needed}} New developments will have pros and cons, and it's hard to tell whether they make the world a better place or not.

Randall has set up a Q&A for this kind of questioning. Most of the them are straightforward, but we'll provide some commentary on selected questions.

''Will [ ] destroy whole industries? Yes.'' A widely adopted technology usually causes another to gradually phase out, and industries will rise and fall as technologies do. This is a bit of a loaded question because "destroy industries" sounds negative, and only covers half the effect — instead of merely destroying them, we're also {{w|Creative destruction|replacing}} them with something (hopefully) better.

''Will teens use [ ] for sex? Yes. Were they going to have sex anyway? Yes.'' Sex is pretty important to almost everyone, so it'll find its way into most generic technologies. Hormone-crazed tech-savvy teenagers are a particularly strong intersection of the two. Parents fearing teen sex might be worried about how their kids would use the technology, but the second question refutes these concerns quite concisely.

''Will [ ] destroy music/art? No.'' Every new technology for reproducing musical and artistic works (such as [https://www.eff.org/deeplinks/2004/03/wicked-player-piano player pianos] and [http://www.forbes.com/sites/joshbarro/2012/01/18/thirty-years-before-sopa-mpaa-feared-the-vcr/ video cassette recorders]) has been accompanied by warnings that it will destroy the industry that supplies it content. The reality is a special case of the "destroy industries" question - old business models will fall but new ones will arise in their place, and art and music as a whole will survive.

''But can't we go back to a time when— No.'' Elderly people {{tvtropes|WhenIWasYourAge|express their disapproval}} of today's technological luxuries, nostalgically longing for a time before Foo or Bar came around. That's just how the stereotype goes, but there is a large helping of truth to it. Usually, their sentiments are not a fair judgement, but an emotional attachment to the olden days and a {{tvtropes|TheyChangedItNowItSucks|resistance to change}}.

''Will [ ] bring about world peace?- No.'' People have been trying to bring about world peace for centuries; sadly, other people are in no such hurry and insist on more conflict to solve their own problems.

The final answer is a depressing and strangely beautiful comment on human nature: ''Will [ ] cause widespread alienation by creating a world of empty experiences? We were already alienated.'' Skeptics may be concerned that a new technology will make people's pleasures and interactions more artificial and shallow; Randall comments that this is already something well known in our society.

From the Title Text, ''Will [ ] allow us to better understand each other and thus make war undesirable?'' describes the usual theory that a technology might use to bring about world peace. Unfortunately, not only does the answer seem to be "no" to World Peace either way, but there's no indication that increased global communication actually facilitates understanding and empathy between distant communities. In fact, many cynics say the Internet has in fact caused the opposite effect, causing people to fracture into like-minded cliques rather than intermingle.

==Transcript==
:[Caption above the chart:]
:The '''simple answers''' to the questions that get asked about every new technology:
:{| class="wikitable"
|Will [ ] make us all geniuses?||align="center"|No
|-
|Will [ ] make us all morons?||align="center"|No
|-
|Will [ ] destroy whole industries?||align="center" |Yes
|-
|Will [ ] make us more empathetic?||align="center" |No
|-
|Will [ ] make us less caring?||align="center" |No
|-
|Will teens use [ ] for sex?||align="center" |Yes
|-
|Were they going to have sex anyway?||align="center" |Yes
|-
|Will [ ] destroy music?||align="center" |No
|-
|Will [ ] destroy art?||align="center" |No
|-
|But can't we go back to a time when-||align="center" |No
|-
|Will [ ] bring about world peace?||align="center" |No
|-
|Will [ ] cause widespread alienation by creating a world of empty experiences?||align="center" |We were already alienated
|}

==Trivia==
* Robinson Meyer of {{w|The Atlantic}} [https://www.theatlantic.com/technology/archive/2013/11/xkcd-is-amazing-but-its-latest-comic-is-wrong/281422/ rather disagreed] with [[Randall Munroe]] on this one...

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

916: Unpickable

2022-05-21T02:41:09Z

Ncpenguin: Undo revision 271436 by Explain xkcd server admin (talk)

{{comic
| number = 916
| date = June 24, 2011
| title = Unpickable
| image = unpickable.png
| titletext = The safe is empty except for an unsolved 5x5 Rubik's cube.
}}
==Explanation==
The comic plays on the idea that geeks and nerds will try to break into high-security areas in order to challenge themselves, instead of to steal things. The vault is labeled "unpickable" as a kind of challenge to break into it, while all the valuables are simply stored in a shoe box ''beside'' the vault.

A 24-pin dual-tumbler {{w|Tubular pin tumbler lock|radial-hybrid lock}} would probably be too bulky and cumbersome to actually exist. The key would be huge, or just plain ''long''. Given the length of the key, it would need to be extremely strong, and the length would be around 96mm, assuming that each notch is 5mm. In theory, though, it would be a remarkably difficult type of lock to pick. The fused 17th pin means that, even with the correct key, it cannot be opened. It would be much easier to simply break open the safe with brute force than to pick it. A simple and nerdy way to open the vault with brute force would be to use canned air, using the principle that cold objects are more brittle. Once the air is emptied onto the lock, it can be easily smashed with an ordinary hammer. This is an example of [[356|nerd sniping]], since the vault is nearly unopenable, nerds and geeks would spend all their time on the vault and ignore the seemingly useless shoe box.

The title text continues the theme, with an unsolved {{w|Professor's_Cube|5x5x5}} Rubik's cube to further challenge and distract the thief.

==Transcript==
:[Caption above the panel:]
:HackerShield
:Geek-Proof Safe System:
:[Two boxes sit side by side. One is a safe with a lock marked "Unpickable." It is labeled: ① 24-pin dual-tumbler radial-hybrid lock (rendered unopenable by a fused 17th pin). The other is a shoebox. It is labeled: ② Shoebox containing your valuables.]

{{Comic discussion}}
[[Category:Comics with color]]

1758: Astrophysics

2022-05-21T02:40:39Z

Ncpenguin: Undo revision 270875 by Explain xkcd server admin (talk)

{{comic
| number = 1758
| date = November 11, 2016
| title = Astrophysics
| image = astrophysics.png
| titletext = DEPARTMENT OF NEUROSCIENCE / Motto: "If I hear the phrase 'mirror neurons' I swear to God I will flip this table."
}}

==Explanation==
In physics, the theory of gravity produced by {{w|general relativity}} combined with {{w|dark matter}} are our current best model for explaining the behavior of gravity and galaxies. The evidence supporting this model is extensive. General relativity accurately predicts the orbit of planets, even precise details like the {{w|Two-body problem in general relativity#Anomalous precession of Mercury|precession of Mercury}} which Newtonian gravity couldn't fully explain. Dark matter, in turn, explains behaviors of galaxies such as their {{w|Galaxy rotation curve|rotation rates}} that were not correctly predicted with general relativity alone. Most astrophysicists believe dark matter exists, either in the form of {{w|Massive compact halo object|an unknown type of star that is too dim to see}}, or {{w|Weakly interacting massive particles|an undiscovered subatomic particle}}.

However, because the concept of dark matter posits something so pervasive yet unknown and so far undetected, it can be difficult to accept, since typically inability to detect something tends to mean non-existence of that thing. One might be reminded of {{w|Aether_(classical_element)|Aether}}, a similar theory that an undetectable substance exists in space to allow light and gravity to travel, although unlike dark matter that has been debunked. Thus, it is common to hear objections to dark matter, with a popular alternative idea being that dark matter can be explained away by a modified theory of gravity.

One such alternative theory which gets proposed regularly is {{w|modified Newtonian dynamics}} (MOND). In MOND, gravity doesn't simply follow the {{w|inverse square law}} but has more complicated behavior. Usually, the extra behavior is either to say that gravitational force can be affected by the acceleration of the particle, or that it goes from inverse-square to just inverse at large distances. It can be appealing because it's relatively simple and seemingly more logical — it just changes our understanding of Newton's law of gravitation, rather than requiring entirely new forms of matter or unknown stars to exist — and because it has some nice side-effects, such as explaining why there seems to be a limit on the density of galaxies. Unfortunately, physicists have explored this avenue and cannot reconcile it with all existing data. One famous counterexample is the {{w|Bullet Cluster}}, where two colliding galaxy clusters are ripping through each other. The mass distribution within the cluster can be inferred through gravitational lensing, and appears to show dark matter and ordinary matter being separated to a certain extent which cannot be explained with MOND. Another counterexample is MOND's incompatibility with observations of the motion of galaxies in galaxy clusters. More generally, MOND isn't compatible with general relativity — which has a huge amount of experimental data in its favour — and a MOND-compatible general relativity would be very complicated and ugly.

This comic illustrates physicists' exasperation for people who constantly try to challenge the existence of dark matter without considering all the evidence and theoretical foundation that support it. Apparently members of this department are so tired of hearing the same old ideas being repeated to them, that they have adopted a motto and even erected a sign in an attempt to clear the dissuation. The specific impetus for this comic may be the press coverage around [https://arxiv.org/abs/1611.02269 this publication] by {{w|Erik Verlinde}} (see popular description of the paper [http://phys.org/news/2016-11-theory-gravity-dark.html here]). It was released online three days before the release of this comic and got a lot of coverage exclaiming "this will prove Einstein wrong". While Verlinde's work on {{w|entropic gravity}} is a serious theory derived from {{w|thermodynamics}} and {{w|quantum information theory}}, it is important to keep in mind that it's just a {{w|pre-print}} and hasn't been peer-reviewed or experimentally verified yet. Verlinde's theory also doesn't match all available data - it [http://motls.blogspot.de/2010/01/erik-verlinde-why-gravity-cant-be.html disagrees with experimental results showing how particles interact with gravity]. Thus, it is still a far cry from being a contender for replacing dark matter.

The title text alludes to a similar issue faced by the Department of {{w|Neuroscience}} from popular misconceptions of {{w|Mirror neurons}}. Mirror neurons are brain cells which trigger when watching someone else do something. Experiments claim to have found mirror neurons in humans and apes, and there are theories that make mirror neurons the foundation of learning, empathy, language and consciousness itself. However, {{w|mirror neurons#Doubts concerning mirror neurons|the evidence for mirror neurons is still patchy}}, and even if they exist, it's very simplistic to try to attribute so much of human behavior to a single type of relatively simple cell. In light of this, the motto of the neuroscientists at the department rightfully reflect their frustration. [http://knowyourmeme.com/memes/flipping-tables Flipping tables] is a common depiction for expressing extreme outrage. It is used here also as a pun because mirrors flip the image in front of them.

Another story of similar press coverage questioning the current established scientific theory was also mentioned two days before the release of this comic, on the YouTube channel Space Time from PBS Digital Studios in their video titled [https://www.youtube.com/watch?v=7UNLgPIiWAg Did Dark Energy Just Disappear?]. This one was regarding the paper [http://www.nature.com/articles/srep35596 Marginal evidence for cosmic acceleration from Type Ia supernovae]. The video concluded that dark energy is still the best explanation. Note this is about the existence of dark energy rather than dark matter. The two are very distinct concepts.

Science papers with results that supposedly disprove solidly founded theories have been the subject before in [[955: Neutrinos]].

==Transcript==
:[A sign on two posts, in the grass in front of a building with windows and double doors, a window on each door, and bars facing outwards. There is a cement walk leading to the doors. On the sign is the text:]
:<big>'''Department of Astrophysics'''</big>
:'''Motto:'''
:''Yes, everybody has already had the idea, "Maybe there's no dark matter—Gravity just works differently on large scales!" It sounds good but doesn't really fit the data.''

{{comic discussion}}

[[Category:Astronomy]]
[[Category:Science]]
[[Category:Physics]]
[[Category:Biology]]

Talk:2620: Health Data

2022-05-18T02:24:32Z

Ncpenguin:

Did a basefor the setup[[Special:Contributions/108.162.246.34|108.162.246.34]] 23:51, 16 May 2022 (UTC)a

"Cure for Causality" sounds like a pretty good band name. [[Special:Contributions/141.101.104.4|141.101.104.4]] 07:13, 17 May 2022 (UTC)

Panel 1 reminds me of a conversation I had with one of my docs. I'd had some blood work done and the doc said, "The numbers look good. For a man your age." I mean, really; for a man my age? I didn't think we'd been talking about some teenager . . . . [[Special:Contributions/172.70.130.161|172.70.130.161]] 08:40, 17 May 2022 (UTC)
:Yeah, but it's possibly even worse when a gynacologist says those exact words... ;) [[Special:Contributions/172.70.162.77|172.70.162.77]] 11:23, 17 May 2022 (UTC)

Is poisoning other than drug overdoses that rare? The linked source states:
"1. Poisoning
Due in large part to the opioid epidemic, poisoning has overtaken car crashes as the country’s leading cause of accidental death, with 64,795 poisoning deaths in 2017, 22,000 of them from opioid painkillers. Additionally, people can be poisoned by common household substances, including:

Carbon monoxide
Pesticides and cleaning products
Lead"

even without the 22,000 opoid painkiller deaths posioning would still be number 1.[[Special:Contributions/162.158.50.68|162.158.50.68]] 09:25, 17 May 2022 (UTC)

:Yeah, I've re-checked that source and it doesn't actually seem that accurate in its numbers. I've replaced it with one that seems better. Wait, actually, that one's also pretty questionable. [https://www.cdc.gov/nchs/data/hestat/poisoning/poisoning.htm This one] seems accurate but not really all the information we're looking for—maybe the CDC has a better article? If someone could find one that is accurate and relevant, that would be a big help. [[User:Ncpenguin|Ncpenguin]] ([[User talk:Ncpenguin|talk]]) 02:24, 18 May 2022 (UTC)

:Well, there are other drugs you can overdose with. However, the most obvious problem with that statistics is that many people would assume that "poisoning" means "being deliberate poisoned", but most of those deaths from poisoning are accidents. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 21:39, 17 May 2022 (UTC)

Should we also link 1471 Gut Fauna wich shows another ewemple of Dr Ponytail practicing a weird form of medicine ?[[Special:Contributions/162.158.50.68|162.158.50.68]] 09:25, 17 May 2022 (UTC)

It is meant as a joke here, but ultimately life might just achieve this one day, uncoupling action from harm.

'Vagueness' is really an insufficient description for the absolute insanity that is blaming the passage of time for your problems. Almost to the point of being humorous in its own right. --[[Special:Contributions/172.69.33.199|172.69.33.199]] 10:13, 17 May 2022 (UTC)
: My nice little homo sapiens is turning into robots and they haven't even solved war. Curse evolution! I should have given them long distance communication thousands of years ago! [[Special:Contributions/172.70.230.143|172.70.230.143]] 15:35, 17 May 2022 (UTC)

Can it be also a pun: 'causality' vs 'casualty'? [[User:Tkopec|Tkopec]] ([[User talk:Tkopec|talk]]) 10:32, 17 May 2022 (UTC)

I think I might be covering up existing advantages with my description of a cold war from my dynamic ip. Be great if somebody could add cited material around that, but of course it's very hard to relate around norms of suppressed discussion. [[Special:Contributions/172.70.110.65|172.70.110.65]] 16:21, 17 May 2022 (UTC)

Check your family tree for any incidence of death. If all your forbears at any past generation are mortal, then science shows that with a high level of confidence that you are mortal.

The Inheritance Pattern of Death by Joseph Eastern, M.D., Carol Drucker, M.D. and John E. Wolf, Jr., M.D., 1982, J.I.R. Volume 28, Issue 22
[[http://www.linkedin.com/in/Comet Comet]] 17:40, 17 May 2022 (UTC)
:Sounds legit, although technically family history is not needed: statistically, everyone is mortal. The leading cause of death is being alive. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 21:39, 17 May 2022 (UTC)

If you have a lot of doctor visits, it's probably the case that you have some chronic illness, and also that you have a lot of measurements. Nevertheless, how many measurements you've had is not a good metric of health. Robert Carnegie rja.carnegie@gmail.com [[Special:Contributions/172.70.90.145|172.70.90.145]] 19:34, 17 May 2022 (UTC)

I'm convinced this particular comic is a snipe at poor control of {{w|availability bias}} and {{w|base rate fallacy}} in family medicine, (perhaps even involving the roots of the opioid crisis and similar scandals) so I added those and did a lot of copy-editing including adding some overlooked comic dialog and trimming about six or seven sentences of proposed possible explanations which were entirely unconvincing to me. If you put one of your potential explanations that I deleted back in, please try to flesh it out a little showing how it might relate to the actual comic instead of just sharing vague abstract philosophical similarities. Thank you! [[Special:Contributions/162.158.166.183|162.158.166.183]] 01:55, 18 May 2022 (UTC)

2620: Health Data

2022-05-18T02:14:20Z

Ncpenguin: Replacing source with a better one

{{comic
| number = 2620
| date = May 16, 2022
| title = Health Data
| image = health_data.png
| titletext = Donate now to help us find a cure for causality. No one should have to suffer through events because of other events.
}}

==Explanation==
{{incomplete|Created by A UNIQUE SEQUENCE OF PAST EVENTS YIELDING FURTHER INFORMATION IF INVESTIGATED - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
[[Cueball]] is at the hospital for some form of check-up. [[:Category:Doctor Ponytail|Doctor Ponytail]] comes in to inform him of the tests they have run, but her statements are frustratingly generic, and so lacking in diagnostic usefulness. She says that his "numbers" have revealed some "measurements" and "variables" but doesn't specify what they are. The fact that there are measurements and variables relate to them having been taken, but is correlated with very few outcomes other than those associated with measurement.

In response to being asked whether that is bad, she ominously says that they are the number one cause of "outcomes." This is obvious, and therefore unhelpful, since every outcome is the product of some set of variables. Additionally, outcomes can be good, bad, or neutral, so it does not address the question.

Doctor Ponytail further states that the past is "a big contributor to" the future, a similarly {{w|Tautology (logic)|tautological}} statement, as Cueball implies by asking whether that is just {{w|causality}}. The doctor replies ominously that causality is the leading cause of death, which is also so tautological as to be meaningless though technically correct.

Cueball tries to cut to the root of the issue by asking "what are my chances of survival?" Ponytail asks what is Cueball's family history, but rather than asking if his family has a history of similar symptoms to Cueball himself she is just asking if he has any family history whatsoever. Her apparent concern on discovering that he does is presumably due to the fact that everyone who has a family history dies, and therefore she sees this as a negative thing. However, this is not medically informative, since everyone has some kind of family history (whether they personally know anything of it or not) and everyone eventually dies.{{Citation needed}}

The comic is likely a comment on the impenetrability of some medical diagnoses, where high levels of jargon and non-contextualized statistics, combined with a lot of hedging language, can leave patients none the wiser about their prospects, or the relative merits of various courses of treatment. Similarly, it could be reflecting on the effects of {{w|availability bias}} and the {{w|base rate fallacy}} when medical practitioners are deriving diagnoses and similar conclusions from medical records designed to highlight the information necessary to diagnose specific well-understood illnesses. It may also be making fun of poorly defined health statistics: statistics for the [https://medicalxpress.com/news/2014-03-poisoning-unintentional-death.html leading causes of accidental death in the United States], for example, typically cite 'poisoning' as the number one cause, even though poisoning other than drug overdoses is actually quite rare. The comic takes vague statistics to the extreme, citing 'causality' as the leading cause of death.

The title text continues the joke, suggesting that researchers are searching for a cure for causality, which is absurd and inconceivable.

The comic as a whole is reminiscent of [[830: Genetic Analysis]] and [[1840: Genetic Testing Results]] (particularly the title text of the latter), as the information given by the doctor in all three is self-evident and useless as a result.

==Transcript==
:[Cueball and Doctor Ponytail are talking to each other. Cueball is sitting on an examination table and Doctor Ponytail, in a doctor's coat, is looking down and reading from a clipboard with some illegible writing on it.]
:Doctor Ponytail: I'm taking a look at your numbers, and it doesn't look good.
:Doctor Ponytail: You have a lot of measurements. Quite a few variables.

:[Same setting but Doctor Ponytail looks up at Cueball.]
:Cueball: Is that... bad?
:Doctor Ponytail: Variables are the #1 risk factor for outcomes.
:Doctor Ponytail: The past is a big contributor to the future.

:[Same setting but Doctor Ponytail puts her arm with the clipboard down.]
:Cueball: Isn't that just causality?
:Doctor Ponytail: Causality is the leading cause of death in this country.

:[Same setting.]
:Cueball: So what are my odds?
:Doctor Ponytail: Do you have a family history?
:Cueball: Of what?
:Doctor Ponytail: Just, in general.
:Cueball: ...Yes?
:Doctor Ponytail: Oh no.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Doctor Ponytail]]
[[Category:Medicine]]

2620: Health Data

2022-05-18T02:02:06Z

Ncpenguin:

{{comic
| number = 2620
| date = May 16, 2022
| title = Health Data
| image = health_data.png
| titletext = Donate now to help us find a cure for causality. No one should have to suffer through events because of other events.
}}

==Explanation==
{{incomplete|Created by A UNIQUE SEQUENCE OF PAST EVENTS YIELDING FURTHER INFORMATION IF INVESTIGATED - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
[[Cueball]] is at the hospital for some form of check-up. [[:Category:Doctor Ponytail|Doctor Ponytail]] comes in to inform him of the tests they have run, but her statements are frustratingly generic, and so lacking in diagnostic usefulness. She says that his "numbers" have revealed some "measurements" and "variables" but doesn't specify what they are. The fact that there are measurements and variables relate to them having been taken, but is correlated with very few outcomes other than those associated with measurement.

In response to being asked whether this is bad, she ominously says that they are the number one cause of "outcomes." This is obvious, and therefore unhelpful, since every outcome is the product of some set of variables. Additionally, outcomes can be good, bad, or neutral, so it does not address the question.

Doctor Ponytail further states that the past is "a big contributor to" the future, a similarly {{w|Tautology (logic)|tautological}} statement, as Cueball implies by asking whether that is just {{w|causality}}. The doctor replies ominously that causality is the leading cause of death, which is also so tautological as to be meaningless though technically correct.

Cueball tries to cut to the root of the issue by asking "what are my chances of survival?" Ponytail asks what is Cueball's family history, but rather than asking if his family has a history of similar symptoms to Cueball himself she is just asking if he has any family history whatsoever. Her apparent concern on discovering that he does is presumably due to the fact that everyone who has a family history dies, and therefore she sees this as a negative thing. However, this is not medically informative, since everyone has some kind of family history (whether they personally know anything of it or not) and everyone eventually dies.{{Citation needed}}

The comic is likely a comment on the impenetrability of some medical diagnoses, where high levels of jargon and non-contextualized statistics, combined with a lot of hedging language, can leave patients none the wiser about their prospects, or the relative merits of various courses of treatment. Similarly, it could be reflecting on the effects of {{w|availability bias}} and the {{w|base rate fallacy}} when medical practitioners are deriving diagnoses and similar conclusions from medical records designed to highlight the information necessary to diagnose specific well-understood illnesses. It may also be making fun of poorly defined health statistics: statistics for the [https://www.gwclaw.com/blog/accidental-death-causes/ leading causes of accidental death in the United States], for example, typically cite 'poisoning' as the number one cause, even though poisoning other than drug overdoses is actually quite rare. The comic takes vague statistics to the extreme, citing 'causality' as the leading cause of death.

The title text continues the joke, suggesting that researchers are searching for a cure for causality, which is absurd and inconceivable.

The comic as a whole is reminiscent of [[830: Genetic Analysis]] and [[1840: Genetic Testing Results]] (particularly the title text of the latter), as the information given by the doctor in all three is self-evident and useless as a result.

==Transcript==
:[Cueball and Doctor Ponytail are talking to each other. Cueball is sitting on an examination table and Doctor Ponytail, in a doctor's coat, is looking down and reading from a clipboard with some illegible writing on it.]
:Doctor Ponytail: I'm taking a look at your numbers, and it doesn't look good.
:Doctor Ponytail: You have a lot of measurements. Quite a few variables.

:[Same setting but Doctor Ponytail looks up at Cueball.]
:Cueball: Is that... bad?
:Doctor Ponytail: Variables are the #1 risk factor for outcomes.
:Doctor Ponytail: The past is a big contributor to the future.

:[Same setting but Doctor Ponytail puts her arm with the clipboard down.]
:Cueball: Isn't that just causality?
:Doctor Ponytail: Causality is the leading cause of death in this country.

:[Same setting.]
:Cueball: So what are my odds?
:Doctor Ponytail: Do you have a family history?
:Cueball: Of what?
:Doctor Ponytail: Just, in general.
:Cueball: ...Yes?
:Doctor Ponytail: Oh no.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Doctor Ponytail]]
[[Category:Medicine]]

2620: Health Data

2022-05-18T02:01:38Z

Ncpenguin: Reordering explanations by likelihood

{{comic
| number = 2620
| date = May 16, 2022
| title = Health Data
| image = health_data.png
| titletext = Donate now to help us find a cure for causality. No one should have to suffer through events because of other events.
}}

==Explanation==
{{incomplete|Created by A UNIQUE SEQUENCE OF PAST EVENTS YIELDING FURTHER INFORMATION IF INVESTIGATED - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
[[Cueball]] is at the hospital for some form of check-up. [[:Category:Doctor Ponytail|Doctor Ponytail]] comes in to inform him of the tests they have run, but her statements are frustratingly generic, and so lacking in diagnostic usefulness. She says that his "numbers" have revealed some "measurements" and "variables" but doesn't specify what they are. The fact that there are measurements and variables relate to them having been taken, but is correlated with very few outcomes other than those associated with measurement.

In response to being asked whether this is bad, she ominously says that they are the number one cause of "outcomes." This is obvious, and therefore unhelpful, since every outcome is the product of some set of variables. Additionally, outcomes can be good, bad, or neutral, so it does not address the question.

Doctor Ponytail further states that the past is "a big contributor to" the future, a similarly {{w|Tautology (logic)|tautological}} statement, as Cueball implies by asking whether that is just {{w|causality}}. The doctor replies ominously that causality is the leading cause of death, which is also so tautological as to be meaningless though technically correct.

Cueball tries to cut to the root of the issue by asking "what are my chances of survival?" Ponytail asks what is Cueball's family history, but rather than asking if his family has a history of similar symptoms to Cueball himself she is just asking if he has any family history whatsoever. Her apparent concern on discovering that he does is presumably due to the fact that everyone who has a family history dies, and therefore she sees this as a negative thing. However, this is not medically informative, since everyone has some kind of family history (whether they personally know anything of it or not) and everyone eventually dies.{{Citation needed}}

The comic is likely on the impenetrability of some medical diagnoses, where high levels of jargon and non-contextualized statistics, combined with a lot of hedging language, can leave patients none the wiser about their prospects, or the relative merits of various courses of treatment. Similarly, it could be reflecting on the effects of {{w|availability bias}} and the {{w|base rate fallacy}} when medical practitioners are deriving diagnoses and similar conclusions from medical records designed to highlight the information necessary to diagnose specific well-understood illnesses. It may also be making fun of poorly defined health statistics: statistics for the [https://www.gwclaw.com/blog/accidental-death-causes/ leading causes of accidental death in the United States], for example, typically cite 'poisoning' as the number one cause, even though poisoning other than drug overdoses is actually quite rare. The comic takes vague statistics to the extreme, citing 'causality' as the leading cause of death.

The title text continues the joke, suggesting that researchers are searching for a cure for causality, which is absurd and inconceivable.

The comic as a whole is reminiscent of [[830: Genetic Analysis]] and [[1840: Genetic Testing Results]] (particularly the title text of the latter), as the information given by the doctor in all three is self-evident and useless as a result.

==Transcript==
:[Cueball and Doctor Ponytail are talking to each other. Cueball is sitting on an examination table and Doctor Ponytail, in a doctor's coat, is looking down and reading from a clipboard with some illegible writing on it.]
:Doctor Ponytail: I'm taking a look at your numbers, and it doesn't look good.
:Doctor Ponytail: You have a lot of measurements. Quite a few variables.

:[Same setting but Doctor Ponytail looks up at Cueball.]
:Cueball: Is that... bad?
:Doctor Ponytail: Variables are the #1 risk factor for outcomes.
:Doctor Ponytail: The past is a big contributor to the future.

:[Same setting but Doctor Ponytail puts her arm with the clipboard down.]
:Cueball: Isn't that just causality?
:Doctor Ponytail: Causality is the leading cause of death in this country.

:[Same setting.]
:Cueball: So what are my odds?
:Doctor Ponytail: Do you have a family history?
:Cueball: Of what?
:Doctor Ponytail: Just, in general.
:Cueball: ...Yes?
:Doctor Ponytail: Oh no.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Doctor Ponytail]]
[[Category:Medicine]]

2620: Health Data

2022-05-17T00:42:33Z

Ncpenguin:

2620: Health Data

2022-05-17T00:40:52Z

Ncpenguin:

2620: Health Data

2022-05-17T00:40:24Z

Ncpenguin: Adding discussion of the intent of the comic

2620: Health Data

2022-05-17T00:33:40Z

Ncpenguin:

2620: Health Data

2022-05-17T00:28:32Z

Ncpenguin:

2620: Health Data

2022-05-17T00:28:08Z

Ncpenguin: Adding to title text and similar comics explanation

1844: Voting Systems

2022-05-16T15:57:51Z

Ncpenguin: Correcting a statement that only FPTP had a "spoiler effect"—Cueball changing which system to prioritize could affect the outcome in FPTP, IRV, Concordet, a Borda Count, and still others.

{{comic
| number = 1844
| date = May 31, 2017
| title = Voting Systems
| image = voting_systems.png
| titletext = Kenneth Arrow hated me because the ordering of my preferences changes based on which voting systems have what level of support. But it tells me a lot about the people I'm going to be voting with!
}}

==Explanation==
This comic is about types of single-winner voting systems:

# '''{{w|Approval voting}}''' has voters "approve" (i.e. select) any number of candidates. The winner is the most-approved candidate. It works with the same unranked ballot as plurality voting, but would allow a "compromise" candidate who is the second choice of a majority to defeat a candidate who is supported by a plurality but disliked by other groups.
# '''{{w|Instant-runoff voting}}''' (also known as Ranked Choice or Preferential Voting) has voters rank the candidates in order of preference. Ballots are initially counted for each elector's top choice. If a candidate secures more than half of these votes, that candidate wins. Otherwise, the candidate in last place is eliminated and removed from consideration. Ballots that had this candidate as the top choice now have the second preference as the top choice (this is the "instant runoff"). The top remaining choices on all the ballots are then counted again. This process repeats until one candidate is the top remaining choice of a majority of the voters or all but one candidate have been eliminated. IRV's proponents have successfully implemented it in a few places, such as the city of San Francisco, and Federal elections in Australia.
# A '''{{w|Condorcet method}}''' elects the candidate that would win a majority of the vote in all of the head-to-head elections against each of the other candidates. A candidate with this property is called the Condorcet winner. Due to the {{w|Condorcet paradox}}, an election with 3 or more candidates might not have a Condorcet winner, so Condorcet methods differ in the secondary set of rules used to handle that situation.
# Not directly mentioned in the comic, '''{{w|First-past-the-post voting}}''' (FPTP, aka '''{{w|Plurality (voting)|plurality voting}}''') is the method currently used in the US, UK, and several other countries. It only allows voters to choose a single candidate. Experts on voting methods agree there are multiple reasons why FPTP is not the best way to implement democracy,<ref>https://www.ippr.org/files/images/media/files/publication/2011/05/Worst%20of%20Both%20Worlds%20Jan2011_1820.pdf</ref><ref>https://plato.stanford.edu/entries/voting-methods/#ExamVotiMeth</ref><ref>https://electionscience.org/voting-methods/spoiler-effect-top-5-ways-plurality-voting-fails/</ref><ref>https://www.fairvote.org/plurality_voting_leaves_elections_open_to_manipulation</ref><ref>https://www.researchgate.net/publication/254419149_And_the_loser_is_Plurality_Voting</ref><ref>https://www.makevotesmatter.org.uk/first-past-the-post</ref><ref>https://blog.realinstitutoelcano.org/en/no-electoral-system-is-perfect-but-some-seem-fairer/</ref> but they made little progress in replacing it in the United States for decades. However, this is changing; the state of Maine and numerous cities have adopted either IRV or Approval in recent years.

'''{{w|Arrow's impossibility theorem}}''' gives a list of criteria for ranked voting systems and states that [http://youtube.com/watch?v=Q60ZXoXP6Hg no system] can satisfy all of them at once, despite that for each of them it may seem "obvious" that an electoral system ought to satisfy it. Some voting theorists (such as Cueball) dislike IRV because it {{w|Comparison of electoral systems#Compliance of selected single-winner methods (table)|fails more of the criteria}} than Condorcet does.

The primary joke in the comic is the premise that people who are pedantic or knowledgeable enough to find Arrow's theorem to be relevant will self-fulfill the theorem by being inclined to disagree on any effort to change the voting system. This is illustrated by Cueball's voting system preference that is contingent on the preferences of other people, which defeats their effort to produce a community-wide ranking.

A secondary joke in the comic is that often voters don't pick their favorite choice in a vote. Instead, they vote for a less favorable, but more likely electable, person as a way to prevent their least favorite choice from being elected. This is commonly called "spoiler effect"; in Arrow's parlance it is a form of {{w|Independence of irrelevant alternatives|IIA criterion failure}}. Cueball's strategic vote switch implies that they may be using FPTP (which they dislike) to make the decision, as FPTP is the only system to involve a potential "spoiler effect" (note, however, that certain vote distributions in systems such as IRV can produce a similarly problematic and illogical effect on the outcome).

A third joke is the recursive self-referencing inherent in voting to choose a voting system.

The title text stipulates that Cueball has no fixed ranking of preference for human candidates, but makes this choice dependent on which voting system is favoured by the group. This exceeds strategic voting considerations as the ranking should have full information, whom Cueball prefers in each situation. Therefore Arrow's impossibility theorem and the analysis behind it assume the ranked preferences of an individual voter as a fixed given. To make them dependent on the voting system makes assessing the efficacy of the voting systems absurd or at least much more complicated to do as a general assessment. That is given as the reason why Arrow would wholeheartedly hate him.

==Transcript==
:[White Hat and Ponytail are standing on either side of Cueball who is talking while lifting one hand.]
:Cueball: I prefer approval voting, but if we're seriously considering instant runoff, then I'll argue for a Condorcet method instead.

:[Caption beneath the panel:]
:Strong Arrow's theorem: The people who find Arrow's theorem significant will never agree on anything anyway.

{{comic discussion}}

<references />

[[Category:Comics featuring White Hat]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]
[[Category:Politics]]
[[Category:Elections]]

2619: Crêpe

2022-05-13T16:36:29Z

Ncpenguin:

{{comic
| number = 2619
| date = May 13, 2022
| title = Crêpe
| image = crepe.png
| titletext = A medicine that makes you put two dots over your letters more often is a diäretic.
}}

==Explanation==
{{incomplete|Created by a ÇRÊPË - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
This comic is a play on the expression "Weird flex but OK" ([https://www.urbandictionary.com/define.php?term=Weird%20flex%20but%20ok definition at Urban Dictionary]). [[Cueball]] has made a {{w|crêpe}}, a thin pancake known for its legendary status in French cuisine. When he says the word "crêpe," however, the {{w|circumflex}} above the "e" comes out odd. Instead of the usual simple angle (^), it looks more like a stubby capital A. [[Megan]], who can apparently see the text inside speech bubbles, comments on the odd shape with the appropriate pun.

The proper French pronunciation of "crêpe" is such that the ê is pronounced as in "get", i.e. "cr-eh-p", but English speakers pronounce it like an "A", i.e. "cr-ay-p", so drawing the circumflex like an "A" references how it would actually be pronounced by [[Cueball]] as an English speaker.

The title text continues the wordplay by punning on {{w|diuretic}} (a substance promoting increased urine production), {{w|Diaeresis (diacritic)|diaeresis}} (a symbol in the form of two dots placed above a vowel), and {{w|diacritic}} (what both the circumflex and the diaeresis are).

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball is holding a plate with a crepe on it, conversing with Megan.]
:Cueball: Check out this crêpe I made!
:Megan: Weird circumflex, but okay.

{{comic discussion}}

2619: Crêpe

2022-05-13T16:36:00Z

Ncpenguin:

{{comic
| number = 2619
| date = May 13, 2022
| title = Crêpe
| image = crepe.png
| titletext = A medicine that makes you put two dots over your letters more often is a diäretic.
}}

==Explanation==
{{incomplete|Created by a ÇRÊPË - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
This comic is a play on the expression "Weird flex but OK" ([https://www.urbandictionary.com/define.php?term=Weird%20flex%20but%20ok definition at Urban Dictionary]). [[Cueball]] has made a {{w|crêpe}}, a thin pancake known for its legendary status in French cuisine. When he says the word "crêpe," however, the {{w|circumflex}} above the "e" comes out odd. Instead of the usual simple angle (^), it looks more like a stubby capital A. [[Megan]], who can apparently see the text inside speech bubbles, comments on the odd shape with the appropriate pun.

The proper French pronunciation of "crêpe" is such that the ê is pronounced as in "get", i.e. "cr-eh-p", but English speakers pronounce it like an "A", i.e. "cr-ay-p", so drawing the circumflex like an "A" references how it would actually be pronounced by [[Cueball]] as an English speaker.

The title text continues the wordplay by punning on {{w|diuretic}} (a substance promoting increased urine production), {{w|Diaeresis (diacritic)|diaeresis}}(a symbol in the form of two dots placed above a vowel), and {{w|diacritic}} (what both the circumflex and the diaeresis are).

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball is holding a plate with a crepe on it, conversing with Megan.]
:Cueball: Check out this crêpe I made!
:Megan: Weird circumflex, but okay.

{{comic discussion}}

2616: Deep End

2022-05-09T21:08:31Z

Ncpenguin: Mostly just reformatting—removed/transferred some redundant sections

{{comic
| number = 2616
| date = May 6, 2022
| title = Deep End
| image = deep_end.png
| titletext = Hey! No running in the back-arc basin!
}}

==Explanation==
{{incomplete|Created by a SUBDUCTING SWIMMING POOL. This article needs additional citations for verification. - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Pools, like oceans, contain water.{{Citation needed}} This comic produces a schematic for the former, derived from science about the latter. On Earth, the surface consists of tectonic plates which move around. In this comic, [[Randall]] equates swimming pools with {{w|plate tectonics}}, to explain how deep ends form in said pools. In actuality, swimming pools aren't really formed by plate tectonics.{{Citation needed}}

A {{w|swimming pool}} is a pool of water, typically used for swimming. Most of these have a deep end and a shallow end. This is intentional, usually to allow less confident swimmers to have somewhere to stand up when needed, while also accommodating activities (such as diving, underwater swimming, rescue practice, etc.) which would not be possible in shallower water.

{{w|Subduction}}, a geological process in which one plate slips beneath another and is forced down into the mantle, is shown here as the reason swimming pools have deep ends. This usually takes place between continental plates and oceanic plates, although it could happen with two oceanic plates. The comic depicts the former, an oceanic plate subducting under a continental one. With tectonic plates, this often results in a deep {{w|oceanic trench}} where one plate slides beneath the other, as well as a {{W|volcanic arc|chain of volcanoes}} above areas farther along the subducting plate, where rock that has liquefied from the subduction comes toward the surface as magma and erupts in volcanoes. An example is the {{w|Cascadia Subduction Zone}} in which the {{w|Juan de Fuca Plate}} is subducting beneath the {{w|North American Plate}}, creating the volcanic {{w|Cascade Range}}.

A splash zone is an area of a waterpark with water being sprayed around, allowing people to get wet without the need to get into the pool. It is not a geological term, but {{W|supralittoral zone|splash zone}} can mean the area next to a coastline that gets splashed by waves. In this comic, the splash zone consists of natural geysers, fed by the bubbles of water that return upwards from the subducted plate.

The title text refers to {{W|back-arc basin|back-arc basins}}, zones of depression that sometimes occur slightly beyond volcanic arcs due to a rift in the tectonic plate. The ban on running in this area likely has more to do with its proximity to the pool area than any danger intrinsic to back-arc basins. A typical safety rule around swimming pools is to avoid running on the pool deck to prevent injuries due to slipping and falling on the hard deck.

Other comics that mention unusual tectonic plate motion include [[1388: Subduction License]] and [[1874: Geologic Faults]].

==Transcript==

{{incomplete transcript}}

:[Caption above the panel:] How deep ends form in pools

:[On the left of the image is the shallowest water in the pool, about the height of [[Megan]]. All the water in the image is grey. She is swimming in the water, and a duck floatie and a beach ball are floating to the left of her. It is labeled:] Shallow End

:[Underneath, a thick layer is labeled:] Pool Floor

:[Going to the right from there, the pool floor begins to curve downwards. As the floor goes down, the water gets deeper. In the deepest area, it is labeled:] Deep End

:[At the bottom of the deep end, there is a curve and a deposit on the pool floor. Within the sediment and pool floor, there are some small pools of trapped water, labeled with three arrows:] Trapped Water

:[On the pool floor an arrow indicates that the oceanic plate is moving left-to-right across the image. It is labeled:] Subduction

:[Some of the water pools are dragged along by the pool floor, while others float up through the ground. The latter are accompanied by several arrows pointing up to indicate upwards movement. These are labeled:] Upward Migration

:[At the surface there is an area labeled:] Splash zone

:[The water erupts in two geysers, the left slightly larger than the other. Several children (small versions of [[Ponytail]], [[Hairy]], and [[Science Girl]] as herself) are playing there. Science Girl is sitting with her arms in the air facing the geysers, and Ponytail and Hairy are running towards the right geyser, Hairy with his arms in the air. The label above this area is:] Splash Zone

:[To the left of the splash zone is the edge of the pool, where a [[Cueball]] figure is in mid-air after jumping off the diving board, with his arms outstretched. This is labeled:] Pool Deck

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Geology]]
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[[Category:Comics featuring Hairy]]
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