explain xkcd - User contributions [en]

582: Brakes

2019-06-28T07:27:37Z

141.101.88.220: /* Trivia */ replace dead link by web.archive.org link

{{comic
| number = 582
| date = May 11, 2009
| title = Brakes
| image = brakes.png
| titletext = It was the funniest 6.5 seconds of my life, although as usual like 80% of it was just Tom and Ray's gasping, hacking laughter.
}}

==Explanation==
A car's brakes fail on a winding mountain road. As a response, the driver calls a live radio phone-in show, overlooking the fact that he is in immediate danger and has no time to gather outside advice before improvising a solution. The driver loses control of the car and plunges over a cliff.

If this ever happens to you,
*Try pumping the brakes, it may rebuild enough pressure to slow you down
*Downshift into second and then first gear, which should limit your vehicle's speed
*Use your "emergency brake", it's not just for parking (this can damage it, but it's better than dying)
*Otherwise, find a safe place to coast to a stop, if possible, or else
*Try to wreck your car in a way that won't kill you or your passengers. Aim for something that will slow you down before stopping you, like a gravel turnout or a stand of bushes.

http://www.wikihow.com/Stop-a-Car-with-No-Brakes

The title text refers to {{w|Tom and Ray Magliozzi}} who were the co-hosts of the weekly radio show {{w|Car Talk}}. It was a car advice/comedy radio show often aired on {{w|NPR}} stations. While there is some actual advice given on the radio show, it's presented as a comedy/entertainment show. Much of the show did involve the hosts "gasping and hacking" as they ask non-relevant questions of the callers and add their own commentary or relate other personal asides and stories.

Since he claims that he has 6.5 funny seconds, he must have connected with them way before going over the cliff. Because in 6.5 seconds a car would fall approximately 200 m (½*g*t^2, with g = 9.81 m/s^2, and t the time in seconds. This will give 207 m, but there will be a lot of air resistance). It is clear from the drawing that the car is still going almost straight out into the air, so it is still almost at the height where it left the road at quite a high speed (to get this far away without turning the engine down towards earth yet.) And the front of the car is just about 5 car lengths to the ground, which would make this a 10-15 m drop only (which would take less than 2 seconds to fall). But according to the comic it seems like he first connected with the show, just when the car has left the road...

==Transcript==
:Of the potential responses to my brakes' failure, I did not choose the best.
:[A cliff is visible, with a car flying off it, and trees below.]
:Voice from car: Hello, you're on Car Talk.

==Trivia==
* NPR made a shirt out of this comic; it can be seen at [https://web.archive.org/web/20161130030315/https://shop.npr.org/products/car-talk-cartoon-t-shirt shop.npr.org].

{{comic discussion}}

Talk:1999: Selection Effect

2018-05-29T13:31:55Z

141.101.88.220:

The selection effect is a bias in the results of a study because the study participants are not a random sample of the general population. For example, a study performed on college students may be biased toward better-educated people, or a study on social interaction may be affected by how many participants have the same first language as the investigators.

[[User:The Dining Logician|The Dining Logician]] ([[User talk:The Dining Logician|talk]]) 19:17, 28 May 2018 (UTC)

One more comic until we hit 2000!
Which means on July 11th, the comic number will finally match up with the date (and will certainly be the only time ever). Like an eclipse!
[[User:Some Commenter|Some Commenter]] ([[User talk:Some Commenter|talk]]) 12:23, 28 May 2018 (UTC)

:Just 49 to go until a big round-number milestone! (and just 1 until a big round number kilometerstone) --[[Special:Contributions/172.68.54.4|172.68.54.4]] 21:54, 28 May 2018 (UTC)

:Well, arguably only two more to go, as there was no comic for #404 (Found this out on accident a few minutes ago looking for something unrelated.) But that means the 1000th comic was the 999th too.[[User:Linker|Linker]] ([[User talk:Linker|talk]]) 12:47, 29 May 2018 (UTC)

I don't think escaping from MRI is that easy. There is reason why it's known to be problem for claustrophobic people. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 22:46, 28 May 2018 (UTC)
:It it not that it is hard to escape from an MRI, unless you are somehow restrained or disabled. It is just that it feels that way because your head is in a tunnel. [[Special:Contributions/141.101.88.220|141.101.88.220]] 13:31, 29 May 2018 (UTC)

1886: Typing Notifications

2017-09-07T12:51:57Z

141.101.88.220: added section and link to NYT article about "texting anxiety"

{{comic
| number = 1886
| date = September 6, 2017
| title = Typing Notifications
| image = typing_notifications.png
| titletext = Over the years I've decided I'd rather have them on than not, but I'm glad there aren't "has opened a blank note to compose a reply to you" notifications.
}}

==Explanation==
{{incomplete|Simple comic, anything missing? Please change this comment when editing this page. Do NOT delete this tag too soon.}}

[[Randall]] has sent a message on an instant messenger to someone else. The message contains simple questions about a show Randall must have undertaken and he insists on an honest answer. The reader tries several times to give a proper answer, probably changing the text, until giving up and sending a simple kind reply.

Typing notifications are a feature of some {{w|instant messaging}} systems. They let you know when the other person in a conversation is typing and preparing a reply. They may appear in different forms, like the literal text "[Contact] is typing." or often has a answer (possibly a different color) containing three animated dots. They give the sender confidence that their message has been received and is being processed.

When the final response is received it is anodyne "It was great", suggesting that the first two deleted drafts could be far more critical. The fact that you know that a message has been deleted or edited twice provokes you to imagine what the deleted drafts may have contained. The issue with typing notifications that Randall is talking about might also just be the difficulty to interpret them. The distant contact might just have been doing something else at the same time, started typing in the wrong conversation, or corrected a typo, but the typing notifications make it seem like they weren't honest.

If one partner of a conversation takes their sweet time to reply, possibly deleting their text and starting from scratch as shown in this comic, the typing notification feature can lead to anxiety, as the person waiting for a response starts to overthink the issue. Thoughts come to mind like the other person might not be honest, try to carefully word a sensitive subject or not care enough about you to quickly reply. If finally the answer arrives and consists of just a laconic "ok" or similar, these feelings become even stronger, leading to thoughts like the other person is trying to hide something. This phenomenon has become so widespread that many people have written about it in newspapers and blogs, calling it [https://www.nytimes.com/2014/08/31/fashion/texting-anxiety-caused-by-little-bubbles.html texting anxiety].

In the title text, Randall mentions opening a blank note to compose a reply, which consists of writing a reply in a separate application and pasting the fully written message before sending it. This may be done for several reasons, like knowing that the answer will be long, and wanting a more useful interface - like a bigger typing area. This may also be done when the person doesn't want their contact to know that an answer is being written, possibly because the answer is a difficult one, and will probably need several attempts and edits before sending. Another reason could be to avoid sending an incomplete or unpolished reply by accident. So while Randall thinks that typing notifications are overall a good thing, he is still glad that they don't include that side case, either because it leaves a way to bypass them, or because "has opened a blank note to compose a reply" informs the contact that the answer is not going to be a typical and nice short message.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[A sequence of eight panels representing the same conversation in an electronic chat. The header always reads:]
:What did you think of my show? Did you like it? Be honest!

:[The reply area on the first seven panels is empty, but on the 2nd, 3rd, 5th, and 7th the input is activated and showing three dots.]

:[On the last panel the reply area reads:]
:It was great!

:[Caption below the panels:]
:My least favorite aspect of typing notifications

{{comic discussion}}

[[Category:Computers]]
[[Category:Social networking]]

1416: Pixels

2015-01-14T17:50:04Z

141.101.88.220: /* du */ be more precise

{{comic
| number = 1416
| date = September 3, 2014
| title = Pixels
| image = pixels.png
| titletext = It's turtles all the way down.
}}
'''NOTE: The above is only a zoomed out version of the this interactive comic.''' For a collection of images that appear when zooming in on this comic, see [[1416: Pixels/Images]].

==Explanation==
{{incomplete|Individual panels need explanations}}
This interactive comic begins with a panel where [[Cueball]] is stacking turtles. This is a reference to the idiom "turtles all the way down," which refers to the problem of infinite recursion: if everything in the universe is "on top of" something else, so to speak, there must be a "bottom." A joking solution to the paradoxical nature of such a bottom is the proposition that {{w|Turtles_all_the_way_down|the world rests on a semi-infinite stack of turtles}}.

As can be read you should "scroll to zoom". This can be done by placing the cursor inside the panel of the comic. When scrolling up (using the mouse wheel) the picture zooms in until the pixels are visible. When you continue to scroll on each pixel then resolves into another comic picture, with black-on-white comic panels making up the white pixels and white-on-black panels making up the black pixels. Scrolling on until you can see the pixels of the comic picture you are now zooming into the process is repeated again and will be so for all subsequent sets of comic panels. Not all white and all black panels are the same; some sets involve more than two different panels, but all involve repetitive tiling.

==Themes==
*Below are all the themes relevant to cover all the images found when zooming in.
*They are sorted in the same order as in the gallery: [[1416: Pixels/Images]].
**Open the gallery in another window - zoom out and then you can see the pictures in this window as you read about them here below:

===Turtles===
Apart from the first image there are two more with a single turtle in them. In one of these the turtle thinks "I am a turtle". This is a reference to [[889: Turtles]] It may say so to the Cueball that is seen standing all alone in another picture.

===What if?===
There is a picture of the book, as it looks and big enough that all text is visible on the front cover. But there is also another version where the author's name is crossed out and replaced with Stephen King and also the word Spooky has been added above the title and below the word xkcd has been crossed and replaced with being afraid.

===Book Launch===
This comic was released on September 3rd, 2014, the day after [[Randall|Randall's]] book ''[http://whatif.xkcd.com/book/ What If]'' was launched. The book is shown and referred to in a number of frames, for example it is [[:File:pixels-upgoer.png|'''literally''' launched]] as a part of an <strike>rocket</strike> [[1133:_Up_Goer_Five|''up goer'']] built by Cueball. There is also a picture with Cueball holding his book, while being excited about the launch.

The model ''up goer'' is [[:File:pixels-assembly-1.png|made of Rocket Parts from KSP]]. KSP is the {{w|Kerbal Space Program}}, a spaceflight simulator which was also [[1350: Lorenz#Themes|part]] of the latest interactive comic [[1350: Lorenz]]. Perhaps xkcd's 'parts' refers to KSP's large community of mod developers who contribute 'parts' to the game, although it was likely intended as nothing more than the humorous supposition that one could purchase physical rocket parts from a simulator. The frames showing the book launch use URLs that include the text "upgoer" in reference to the [[Up Goer Five]] comic.

In the end the up goer leaves the Earth after one orbit and then flies through space.

===Needs More Struts===
{{w|Strut|Struts}} are structural members in engineering, and are are one of the components used in Kerbal Space Program to construct rockets. 'Needs More Struts' seems to be a meme amongst players of Kerbal Space Program, along the lines of 'When in doubt, overengineer'. Megan deems Cueball's rocket to be insufficiently structurally sound, and declares that it "[[:File:pixels-assembly-4.png|Needs More Struts]]"

===The Only Copy===
Cueball & Megan turn to each other having just launched the What-If book rocket into space (construction and launch are seen in other panels). Perhaps Megan realizes they may have misunderstood the term 'book launch' and that they may have just lost ''[[:File:pixels-upgoer-6.png|the only copy]]'' of the book.

===Space objects===
There are both the Moon, the Sun, Saturn and two images just with stars.

===Sky===
In four pictures Cueball and Megan are sitting below the stars. In the second the following conversation takes place:
:Cueball: Someone once told me the great kings of the past look down on us...
:Megan: From the stars?
:Cueball: Just in general.
The second panel is a reference to Disney's [http://lionking.wikia.com/wiki/The_Great_Kings_of_the_Past The Lion King]. Early in the film, Mufasa tells Simba that the great kings of the past look down on them from the stars. Later on, Simba recalls this to his companions, Timon and Pumba (who don't take him seriously). In the film, the kings of the past literally look down on--and watch over--the characters, which is how Megan interprets Cueball's initial statement. Cueball's reply that they just look down on us in general shows that he means the kings of the past figuratively look down on us (they view us as inferior or beneath them).

In the next image a shooting star is seen above them. The final picture looks to identical to the first?

===Mario===
A series of 8 images are called ''Mario''. The first is called ''entry'', and has a picture of a TV on a low stand. The next four has Megan in front of said TV, holding a video game controller. The cable is connected to something inside the stand. She first sits on her knees, then on her butt. In the third picture she is lying down. What follows is a picture which is an inverse of the sitting picture. The last three images seem to depict a level from one of the {{w|Super Mario Bros.}} games. It appears to be nighttime, something which never occurs in the SMB games. In the upper right one can see the iconic bricks which Mario can smash, two clouds appear stationary in the background, and a crude depiction of Mario is standing in the lower left. Over the course of the three images, a galaxy rises into the sky. It does not look like the Milky Way would from anywhere on Earth, suggesting that Mario is somewhere outside our galaxy, or that it is not the Milky Way at all. The shape also seems to be a mix of spiral and ellipse. The rise of the galaxy could be meant to show how much time Megan spends playing the game, and this might also be why Cueball wishes to [[#Shut Down the Server|throw water on the server]].

===Shut Down the Server===
Cueball tells an offscreen character that he is going to [[:File:pixels-server-1.png|shut down the server]], while carrying a bucket of water.

Usually shutting down a {{w|Server (computing)|server}} is done via the operating system or software, or (not recommended) turning it off or pulling the power plug. But in this case it appears that cueball is simply going to douse it with water, likely resulting in serious water damage to the hardware.

===Clouds===
In five pictures Megan is floating in the clouds. Only two pictures with Megan, two only with clouds and one only with birds as seen from a distance.

===Walking===
In two images Cueball and Megan are seen walking. One normal black on white close up, and one inverse seen from afar. These may be relevant to the two next ([[#Time Turners]] and [[#Stockholm Syndrome]]) where they are seen talking while walking.

===Time Turners===
The time turner is a device from the {{w|Harry Potter}} series of novels by {{w|JK Rowling}}. It allows the user to re-live a period of time over again. In the third novel Hermione is given the time-turner to allow her to take extra classes, however it is eventually used to spare Buckbeak the hippogryph from execution. This prompted many questions regarding why time-turners weren’t used on other occasions to save people's lives (among other things).

While J.K Rowling has “[http://pottermore.wikia.com/wiki/Time-Turner solved the problem to her own satisfaction]” she admits that she entered into the subject of time-travel too lightly.

[[:File:pixels-time-turner.png|This panel]] jokes that if the real life JK Rowling had a fictional time-turner which worked, she would have gone back and removed the time-turner plotline from the book, saving her all the hassle of dealing with the resulting time-travel questions. This act would result in a time-travel paradox.

===Stockholm Syndrome===
{{w|Stockholm syndrome}} is the name for a psychological phenomenon, in which hostages develop sympathy, empathy and/or positive feelings towards their captors. These feelings are usually seen as irrational, seeing as the hostage is held against their wishes, usually with the threat of physical harm or death.

[[:File:pixels-stockholm.png|This panel]] asks "How do we know anyone really ''wants'' to live in Stockholm?", questioning whether everyone who lives in the city of Stockholm is in fact held hostage there and only stays because they have developed to like life there (due to Stockholm Syndrome).

===Fire Hydrant===
[[Black Hat]] is talking to a fireman, with a fire engine on fire in the background, he asks "To be fair, what else would you expect to come out of a "[[:File:pixels-fire-hydrant.png|fire hydrant]]"?"

Black Hat appears to have managed to replace the usual water supply to the {{w|fire hydrant}} with actual fire. Thus when the hydrant is used, the result is, quite literally, fire (or oil with possibly flint and steel contraptions to cause fire). In Black Hat's logic, a hydrant which delivers water should be called a water hydrant.

===Eeee===
Megan hears a very long stretched ''EEEEEEEEEEEEE'' sound which goes over 6 images. It turns out it is a large letter '''E''' that shouts ''EEEEEEE!!!''. In total there are 64 small E emanating from the big one. There is also a picture with two big white E on black background. Those E are larger than the E that shouts.

===Evolution===
The {{w|March of Progress}} image is a famous and instantly recognisable image showing the stages of human evolution by way of a series of primate figures as if marching in a line. The panel parodies the March of Progress image, with [[:File:pixels-evolution.png|5 ducklings following an adult duck]]. In this case, rather than portraying selected individuals millions of years apart, the March shows evolution in action on a human timescale, the mother taking care of her ducklings. The comic has some resemblance to [[537: Ducklings]].

===Rope===
Four ropes cross diagonally across this black picture. Looks good when there are many of them in the same place.

===Chess and Cantor Set Fractals===
There are two chess boards on black and white background with smaller chessboards drawn upon them in a {{w|Fractal}} pattern.

[[:File:pixels-cantor.png|One panel]] contains a number of lines and dots, which are in fact a depiction of the first 5 steps of a {{w|Cantor set|Cantor Ternary Set}}, mirrored about the horizontal centreline (see {{w|File:Cantor set in seven iterations.svg|reference image}}). The Cantor ternary set is constructed by repeatedly deleting the open middle thirds of a set of line segments.

The Cantor Set is one of the canonical examples of a fractal, a shape whose individual parts resemble the whole. The use of the Cantor Set in this comic is self-referential, in that the comic, itself, is composed of parts of the same shape as the whole.

===Atom etc===
There is a picture of a Bohr Model atom with point electrons surrounding a nucleus of protons and neutrons. The atom is a {{w|Carbon}} atom which is essential for all living matter and therefore essential for evolution. There is also a picture of what is probably a vibrating cosmic string fragment (a concept in {{w|string theory}}). Despite the {{w|Werner Heisenberg|Heisenberg's}} {{w|Uncertainty Principle}}, getting down to the string does not mean that the cartoon viewer has reached the "bottom" of zooming in on pixels - zooming in on the loop will show a picture of string.

===Holism, Reductionism, Mu===
These three words refer to "A MU offering", an essay by {{w|Douglas Hofstatder}} in his book {{w|Godel, Escher, Bach}} (which was referenced by Randall in [[24: Godel, Escher, Kurt Halsey]]). It includes a similar multiple level drawing: {{w|Mu (negative)|the word MU}} is composed of copies of the words [[:File:pixels-holism.png|HOLISM]] and [[:File:pixels-reductionism.png|REDUCTIONISM]], each of which are in turn made of smaller copies of the other, which are in turn made of [http://newtonexcelbach.wordpress.com/2011/02/16/two-more-letters/ tiny copies] of the word [[:File:pixels-mu.png|MU]].

These panels can be found inside panels with Megan.

===du===
"[[:File:pixels-du.png|du]]" is a {{w|POSIX}} (think {{w|Linux}}/{{w|Mac OS X}}) command to indicate the "disk usage" of a file or directory.

~$ du -s video/
4170882256

This is a command that shows how large all the files are in this user's "video" directory - presumably where they store their personal videos. The units of the result is probably kilobytes (depending on settings)

This number is clearly large and difficult to parse, and the units are not clear (to a bystander). More appropriate units would be gigabytes rather than bytes. The du command offers an option to display units in "human readable format", which will adapt to use kilobytes, megabytes, gigabytes, terabytes, etc. as appropriate. The next command purports to request the same result in more human-readable form.

~$ du -hs video/
A lot.
~$

It seems that the computer, rather than giving a specific answer, simply says that the size of the video directory is "A lot."

The final line indicates the computer is now ready to accept a new command.

==Transcript==
:[Cueball is stacking turtles, and is about to put the fourth turtle on his pile. At the bottom right there is a small panel. Inside this is written:]
:Scroll to zoom

:[When zooming in there will be several panels with text. The transcript of these may not be possible to complete - but add the transcript of these panels here: [[1416: Pixels/Transcript|interactive transcript]]]

==Trivia==
===Gallery===
[[1416: Pixels/Images|This gallery]] contains the [http://azttm.wordpress.com/2014/09/03/xkcd-com-1416-pixels/ 79 images used in this comic]. The images are related in a [http://www.explainxkcd.com/wiki/images/3/37/1416_Pixels_layout.png directed graph].

===Images Database===
This google sheet describes all possible images, their associated codes, and what possible images can be used as sub-images for each zoom level: https://docs.google.com/spreadsheets/d/1nldKAkeVcK606CY12KI9bah9rDmK9E7CZOyinsEj2Lo/edit?usp=sharing

===Image scraping script===
This gist recursively downloads all possible images:
https://gist.github.com/Aaron1011/d3b56325881cd639506a

===Bugs===
*Doesn't seem to work properly in all browsers (e.g. Firefox and Safari on MacOSX), giving "TypeError: this.data is null" in line 173 of zoom.js: "var item = this.data.get(dims)"
*Firefox on Lubuntu 14.04 (presumably other Ubuntu/Linux distros as well) will allow zooming in, and then freeze when each pixel is about 1/3 of the pane.
*Doesn't seem to work in IE8, comic is blank, but title text works.
*Does not work on xkcd.org neither www.xkcd.org in Firefox and Chrome. Currently you should visit http://xkcd.com for this comic to work properly.
*Also, it doesn't work on HTTPS.
*Very slow and consumes a ridiculous amount of memory (>4GB) in Firefox.

{{comic discussion}}
[[Category:Interactive comics]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Black Hat]]

1426: Reduce Your Payments

2014-09-26T10:36:38Z

141.101.88.220: Citation needed

{{comic
| number = 1426
| date = September 26, 2014
| title = Reduce Your Payments
| image = reduce_your_payments.png
| titletext = I tried oxidizing them, but your bank uses some really weird paper and it wouldn't light.
}}

==Explanation==
{{incomplete|This explanation states what is obvious in the comic without explaining. A description of Sodium borohydride's effects on paper are required. }}

[[Black Hat]] walks into a room where [[Cueball]] sits in an armchair. Black Hat says to Cueball that he can reduce his mortgage bills, while holding a docket of paper, presumably Cueball's bill. Black Hat uses the same formulation many internet advertisements use: "Discover this (strange/new/amazing...) trick to (lose weight/reduce your mortgage bills/meet amazing women)" to gather clicks{{Citation needed}}. Cueball wants to know how and Black Hat responds by mentioning {{w|Sodium_borohydride|sodium borohydride (NaBH<sub>4</sub>)}}.

Sodium borohydride is a strong {{w|Reducing_agent|reducing agent}}, meaning in a chemical reaction it will "reduce" something else, by contributing (an) electron(s). It is in fact used during the [http://www.borax.com/library/articles/news-and-events/news-release/paper's-tiger manufacture of paper], in order to bleach the pulp and improve the resulting papers properties.

This comic is a typical switcharound pun. Cueball expects the value (on a bill) you have to pay reduced, while Black Hat uses the chemical meaning of reducing. Cueball, realizing this, then proceeds to say "I hate you", when he realizes the pun.

The title text implies that Black Hat has already attempted to oxidize (as the contrary of the chemical "reduce") the paper mortgage bill by burning it but the paper would not light.

Black Hat's "weird trick" actually works, yet in an unexpected manner, and does not solve the actual problem.

==Transcript==
:[Cueball sits on a sofa and Blackhat walks into the frame from behind.]
:Blackhat: I discovered this weird trick for reducing your mortgage payments!
:Cueball: What?
:Blackhat: Sodium borohydride.
:Cueball: ...I hate you.

{{comic discussion}}