explain xkcd - User contributions [en]

Talk:1654: Universal Install Script

2016-03-11T16:02:39Z

108.162.217.17: /* Errors */

A few comments:

* curl | sh is still a common way to install things like package managers. Until you have Homebrew, or pip (for older versions of Python that didn't bootstrap it), etc., you can't use a package manager to install it, so they usually give you a one-liner to download and run a shell script that installs the package manager. Of course this isn't an issue for linux distros (which, unlike OS X, come with a built-in package manager).
* Mac users probably only interact with Steam through its GUI, but on linux, running steamcmd is more common. And this command will install a game that's in your library but not downloaded yet.
* I don't know why _only_ apt gets a sudo, but for brew, and for typical installations of Python on a Mac, you don't want or need sudo; they encourage you to leave the relevant directory writable by your normal user account.
* This script only handles the popular package managers on OS X and current popular linux distros. No port for FreeBSD, no Choco for Windows, etc. In fact, if you try it on Windows, you should get an error message telling you that you've ruined the joke by trying to extend it.

--[[Special:Contributions/162.158.255.82|162.158.255.82]] 10:44, 11 March 2016 (UTC)

Also, docker is a deployment tool for deploying isolated, complete applications. For example, instead of just installing the Python scripts to run your web server behind nginx, you'd deploy nginx, Python, the modules you need for each, the appropriate configurations, a variety of tools the server depends on, and your scripts all as one big hunk of stuff. The docker website probably explains it better. :) --[[Special:Contributions/162.158.255.82|162.158.255.82]] 10:50, 11 March 2016 (UTC)

== Errors ==

He forgot the .git on the end of the git clone command.

--[[Special:Contributions/173.245.54.53|173.245.54.53]] 11:16, 11 March 2016 (UTC)

: Actually, the command works fine anyway. I don't know whether it's git or GitHub which works around this. [[Special:Contributions/141.101.75.161|141.101.75.161]] 11:46, 11 March 2016 (UTC)

Also, the TLD in the curl. And, the install script would probably be at /install.sh, and use sh not bash.

Sh is generally preferred in scripting anyway since it comes on all *nix systems by default. Bash is on a very large number of systems, but not all.

Apt-get should have the -y flag.

If installing a program, npm should be given the -g flag to install globally instead of just in this directory.

Most programs print errors (as would arise if a package did not exist) to the console even if they are run with an & to indicate it should not be attached to the session. In this case, it should be &>/dev/null.

The program as a whole ignores previous programs and continues anyway. If it was found in one package manager, it would be a a very bad idea to write over it with another package manager's copy. This is part of the point of the comic, as is noted in the title text, but it's still an error.
--[[Special:Contributions/173.245.54.53|173.245.54.53]] 11:38, 11 March 2016 (UTC)

He forgot cpanm. :) [[Special:Contributions/108.162.217.17|108.162.217.17]] 16:02, 11 March 2016 (UTC)

== Question ==

That whooshing sound you heard was the Linux-y stuff going way over my head, but could part of the joke be that he's trying to install money? With all the $1's in the script? [[Special:Contributions/173.245.54.53|173.245.54.53]] 15:47, 11 March 2016 (UTC)
:No, all those $ are just part of the scripting language -- the $1's get replaced with the name of the program you're trying to install. There are so many $ simply because he's included so many install commands, each one of which needs the name of the program.[[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 16:00, 11 March 2016 (UTC)

Talk:398: Tap That Ass

2015-11-19T16:22:35Z

108.162.217.17:

no, "tap" in the first frame means "pick," as in, "today the mayor tapped Mike Smith to be interim head of the planning department." No idea where you got the borrowing money bit from. [[User:MR|MR]] ([[User talk:MR|talk]]) 22:27, 5 March 2013 (UTC)MR
:Agreed. Someone who is better at life than us should correct it.--[[User:JSekula71|JSekula71]] ([[User talk:JSekula71|talk]]) 20:29, 27 April 2013 (UTC)
::Also agreed. I've changed it, but it could be better :-) [[User:Markhurd|Mark Hurd]] ([[User talk:Markhurd|talk]]) 02:35, 28 April 2013 (UTC)
:::Changed the explanation about the first panel and mentioned the title text at the end, but it really could be better:D [[Special:Contributions/141.101.97.215|141.101.97.215]] 05:21, 23 April 2014 (UTC)
It should be known that "xkcd: Volume 0" includes a continuation of this comic in which Cueball has sex with the tree and eventually a child. [[Special:Contributions/108.162.217.17|108.162.217.17]] 16:22, 19 November 2015 (UTC)

what if?

2015-11-17T10:52:53Z

108.162.217.17: Clarifying a Word Choice

what if?

2015-10-18T17:13:34Z

108.162.217.17:

:''Not to be confused with [[17: What If]].''
[[File:whatifbanner.jpg]]

'''''[http://what-if.xkcd.com/ what if?]''''' is a blog hosted on the [[xkcd]].com domain and written by [[Randall Munroe]] with entries posted [http://www.phrases.org.uk/meanings/once-in-a-blue-moon.html every month]. On the blog, Randall uses his degree in physics and strong scientific background to discuss hypothetical physics questions apparently submitted by readers.
Since 2014 , there's also a book of the blog.

Unlike other sites which answer readers' questions, ''what if?'' typically takes the question beyond the original scope likely intended by the reader and takes it to some extreme for humorous effect. For example, in [http://what-if.xkcd.com/1/ the first article], he discusses what would happen if a baseball were pitched at 90% of the speed of light. After effectively describing what would occur as a nuclear explosion, leveling the stadium and the surrounding mile radius, he concludes with the note ''"A careful reading of official Major League Baseball Rule 6.08(b) suggests that in this situation, the batter would be considered 'hit by pitch', and would be eligible to advance to first base."''

The questions Randall tackles range from realistic possibilities (e.g. the probability of achieving a [http://what-if.xkcd.com/2/ perfect SAT score by guessing]) to completely fictional questions (e.g. [http://what-if.xkcd.com/3/ How much Force power] can {{w|Yoda}} output?). In his explanations, Randall, often uses diagrams in an ''xkcd'' style. Regardless of the context, Randall tends to take the questions extremely literally and responds seriously to them, even if they are whimsical (such as the Yoda question). This is clear from his response to the question of what would happen if everybody on Earth stood together and [http://what-if.xkcd.com/8/ jumped at the same time]. After acknowledging that the question has been answered elsewhere, he recaps the result, but then focuses more intently on the unasked resulting issue of the aftermath of everyone on Earth being magically transported to one location as they all try to return home.

This site is not under [http://creativecommons.org/licenses/by-nc/2.5/ Creative Commons Attribution-NonCommercial 2.5 License] like [[xkcd]] is.

Randal took a hiatus from updates from May 2015 to July 14th 2015 with a note stating "What If updates are temporarily on hold, and will resume on July 14th, 2015 at 7:49:59 AM EDT." This was the date and time that the New Horizons probe achieved its closest approach to Pluto. The article for July 14th was about the New Horizons probe.

==The book==
{{Incomplete|Maybe give the most (popular) articles their own link. That would be nice. A full list of all articles can be viewed [https://what-if.xkcd.com/archive/ here]}}
Randall announced his ''what if?'' book on 12 March 2014 in [http://blog.xkcd.com/2014/03/12/what-if-i-wrote-a-book/ the blag]. It was published on September 2, 2014, and the UK edition of the book was published on September 4, 2014.
[[Image:What_If?.jpeg|frame|The general cover of the book]]
It is just like 'xkcd:volume 0' a compilation of some questions from the website, but half of them are new.

In the UK edition of the book, Randall included a preface about his thoughts on the units used in the UK. (The Metric System)
====Summary====
'''The summary on the back of the book reads:'''

''Randall Munroe left NASA in 2005 to start up his hugely popular site XKCD 'a web comic of romance, sarcasm, math and language' which offers a witty take on the world of science and geeks. It now has 600,000 to a million page hits daily. Every now and then, Munroe would get emails asking him to arbitrate a science debate. 'My friend and I were arguing about what would happen if a bullet got struck by lightning, and we agreed that you should resolve it . . . ' He liked these questions so much that he started up What If.

*If your cells suddenly lost the power to divide, how long would you survive?
*How dangerous is it, really, to be in a swimming pool in a thunderstorm?
*If we hooked turbines to people exercising in gyms, how much power could we produce?
*What if everyone only had one soulmate?
*When (if ever) did the sun go down on the British empire?
*How fast can you hit a speed bump while driving and live?
*What would happen if the moon went away?

''In pursuit of answers, Munroe runs computer simulations, pores over stacks of declassified military research memos, solves differential equations, and consults with nuclear reactor operators. His responses are masterpieces of clarity and hilarity, studded with memorable cartoons and infographics. They often predict the complete annihilation of humankind, or at least a really big explosion. Far more than a book for geeks, WHAT IF: Serious Scientific Answers to Absurd Hypothetical Questions explains the laws of science in operation in a way that every intelligent reader will enjoy and feel much the smarter for having read.''

'''The summary on the back of the UK edition of the book reads:'''

''Hey! Thanks for looking at my book. If you're thinking about buying it, here are some things you might want to know:''

Humans can't digest the cellulose in paper, but if we could, eating this book would give you about 2,300 calories (including the cover).

This book can't stop most bullets; if you want to use it for armour, you may want a lot more than one copy.

If you have a good arm, you could probably throw this book about 45 feet. With practice, it's possible to throw a book every 800 milliseconds, which means that if human attackers are sprinting towards you, you'll have three or four chances to hit them before they reach you. If, on the other hand, you're being attacked by a coyote, it's higher top speed means you'll have only one chance to hit it. Aim carefully.

''HIDDEN FEATURE: The inside of this book has words and pictures, plus a special UK foreword.'' It answers many important questions, including whether you could jump from a plane with a helium tank and inflate balloons fast enough to slow your fall and survive (yes) and whether you could hide from a supersonic windstorm in Finland (yes, but it won't help).

==Articles==
*[http://www.what-if.xkcd.com/1/ Relativistic baseball]
*[http://www.what-if.xkcd.com/2/ SAT guessing]
*[http://www.what-if.xkcd.com/3/ Yoda]
*[http://www.what-if.xkcd.com/4/ A mole of moles]
*[http://www.what-if.xkcd.com/5/ Robot apocalypse]
*[http://www.what-if.xkcd.com/6/ Glass half empty]
*[http://www.what-if.xkcd.com/7/ Everybody out]
*[http://www.what-if.xkcd.com/8 Everybody jump]
*[http://www.what-if.xkcd.com/9 Soul mates]
*[http://www.what-if.xkcd.com/10 Cassini]
*[http://www.what-if.xkcd.com/11 Droppings]
*[http://www.what-if.xkcd.com/12 Rain drop]
*[http://www.what-if.xkcd.com/13 Laser pointer]
*[http://www.what-if.xkcd.com/14 Short answer section]
*[http://www.what-if.xkcd.com/15 Mariana trench explosion]
*[http://www.what-if.xkcd.com/16 Today's topic: Lightning]
*[http://www.what-if.xkcd.com/17 Green cows]
*[http://www.what-if.xkcd.com/18 BB gun]
*[http://www.what-if.xkcd.com/19 Tie vote]
*[http://www.what-if.xkcd.com/20 Diamond]
*[http://www.what-if.xkcd.com/21 Machine gun jetpack]
*[http://www.what-if.xkcd.com/22 Cost of pennies]
*[http://www.what-if.xkcd.com/23 Short answer section II]
*[http://www.what-if.xkcd.com/24 Model rockets]
*[http://www.what-if.xkcd.com/25 Three wise men]
*[http://www.what-if.xkcd.com/26 Leap seconds]
*[http://www.what-if.xkcd.com/27 Death rate]
*[http://www.what-if.xkcd.com/28 Steak drop]
*[http://www.what-if.xkcd.com/29 Spent fuel pool]
*[http://www.what-if.xkcd.com/30 Interplanetary Cessna]
*[http://www.what-if.xkcd.com/31 FedEx bandwidth]
*[http://www.what-if.xkcd.com/32 Hubble]
*[http://www.what-if.xkcd.com/33 Ships]
*[http://www.what-if.xkcd.com/34 Twitter]
*[http://www.what-if.xkcd.com/35 Hairdryer]
*[http://www.what-if.xkcd.com/36 Cornstarch]
*[http://www.what-if.xkcd.com/37 Supersonic stereo]
*[http://www.what-if.xkcd.com/38 Voyager]
*[http://www.what-if.xkcd.com/39 Hockey puck]
*[http://www.what-if.xkcd.com/40 Pressure cooker]
*[http://www.what-if.xkcd.com/41 Go west]
*[http://www.what-if.xkcd.com/42 Longest sunset]
*[http://www.what-if.xkcd.com/43 Train loop]
*[http://www.what-if.xkcd.com/44 High throw]
*[http://www.what-if.xkcd.com/45 ISS music video]
*[http://www.what-if.xkcd.com/46 Bowling ball]
*[http://www.what-if.xkcd.com/47 Alien astronomers]
*[http://www.what-if.xkcd.com/48 Sunset on the British Empire]
*[http://www.what-if.xkcd.com/49 Sunless Earth]
*[http://www.what-if.xkcd.com/50 Extreme boating]
*[http://www.what-if.xkcd.com/51 Free fall]
*[http://www.what-if.xkcd.com/52 Bouncy balls]
*[http://www.what-if.xkcd.com/53 Drain the oceans]
*[http://www.what-if.xkcd.com/54 Drain the oceans: Part II]
*[http://www.what-if.xkcd.com/55 Random sneeze call]
*[http://www.what-if.xkcd.com/56 Restraining an airplane]
*[http://www.what-if.xkcd.com/57 Dropping a mountain]
*[http://www.what-if.xkcd.com/58 Orbital speed]
*[http://www.what-if.xkcd.com/59 Updating a printed Wikipedia]
*[http://www.what-if.xkcd.com/60 Signs of life]
*[http://www.what-if.xkcd.com/61 Speed bump]
*[http://www.what-if.xkcd.com/62 Falling with helium]
*[http://www.what-if.xkcd.com/63 Google datacenters on punchcards]
*[http://www.what-if.xkcd.com/64 Rising steadily]
*[http://www.what-if.xkcd.com/65 Twitter timeline height]
*[http://www.what-if.xkcd.com/66 500MPH]
*[http://www.what-if.xkcd.com/67 Expanding earth]
*[http://www.what-if.xkcd.com/68 Little planet]
*[http://www.what-if.xkcd.com/69 Facebook of the dead]
*[http://www.what-if.xkcd.com/70 The constant groundskeeper]
*[http://www.what-if.xkcd.com/71 Stirring tea]
*[http://www.what-if.xkcd.com/72 Loneliest human]
*[http://www.what-if.xkcd.com/73 Lethal neutrinos]
*[http://www.what-if.xkcd.com/74 Soda planet]
*[http://www.what-if.xkcd.com/75 Phone keypad]
*[http://www.what-if.xkcd.com/76 Reading every book]
*[http://www.what-if.xkcd.com/77 Growth rate]
*[http://www.what-if.xkcd.com/78 T-rex calories]
*[http://www.what-if.xkcd.com/79 Lake tea]
*[http://www.what-if.xkcd.com/80 Pile of viruses]
*[http://www.what-if.xkcd.com/81 Catch!]
*[http://www.what-if.xkcd.com/82 Hitting a comet]
*[http://www.what-if.xkcd.com/83 Star sand]
*[http://www.what-if.xkcd.com/84 Paint the Earth]
*[http://www.what-if.xkcd.com/85 Rocket golf]
*[http://www.what-if.xkcd.com/86 Far-travelling objects]
*[http://www.what-if.xkcd.com/87 Enforced by radar]
*[http://www.what-if.xkcd.com/88 Soda sequestration]
*[http://www.what-if.xkcd.com/89 Tungsten countertop]
*[http://www.what-if.xkcd.com/90 Great tree, great axe]
*[http://www.what-if.xkcd.com/91 Faucet power]
*[http://www.what-if.xkcd.com/92 One-second day]
*[http://www.what-if.xkcd.com/93 Windshield raindrops]
*[http://www.what-if.xkcd.com/94 Billion-story building]
*[http://www.what-if.xkcd.com/95 Pyramid energy]
*[http://www.what-if.xkcd.com/96 $2 undecillion lawsuit]
*[http://www.what-if.xkcd.com/97 Burning pollen]
*[http://www.what-if.xkcd.com/98 Blood alcohol]
*[http://www.what-if.xkcd.com/99 Starlings]
*[http://www.what-if.xkcd.com/100 WWII films]
*[http://www.what-if.xkcd.com/101 Plastic dinosaurs]
*[http://www.what-if.xkcd.com/102 Keyboard power]
*[http://www.what-if.xkcd.com/103 Vanishing water]
*[http://www.what-if.xkcd.com/104 Global snow]
*[http://www.what-if.xkcd.com/105 Cannibalism]
*[http://www.what-if.xkcd.com/106 Ink molecules]
*[http://www.what-if.xkcd.com/107 Letter to mom]
*[http://www.what-if.xkcd.com/108 Expensive shoebox]
*[http://www.what-if.xkcd.com/109 Into the blue]
*[http://www.what-if.xkcd.com/110 Walking New York]
*[http://www.what-if.xkcd.com/111 All the money]
*[http://www.what-if.xkcd.com/112 Balloon car]
*[http://www.what-if.xkcd.com/113 Visit every state]
*[http://www.what-if.xkcd.com/114 Antimatter]
*[http://www.what-if.xkcd.com/115 Into the Sun]
*[http://www.what-if.xkcd.com/116 No-rules NASCAR]
*[http://www.what-if.xkcd.com/117 Distant death]
*[http://www.what-if.xkcd.com/118 Physical salary]
*[http://www.what-if.xkcd.com/119 Laser umbrella]
*[http://www.what-if.xkcd.com/120 Alternate universe what ifs]
*[http://www.what-if.xkcd.com/121 Frozen rivers]
*[http://www.what-if.xkcd.com/122 Lava lamp]
*[http://www.what-if.xkcd.com/123 Fairy demographics]
*[http://www.what-if.xkcd.com/124 Lunar swimming]
*[http://www.what-if.xkcd.com/125 Bowling ball]
*[http://www.what-if.xkcd.com/126 Stairs]
*[http://www.what-if.xkcd.com/127 Tug of war]
*[http://www.what-if.xkcd.com/128 Zippo phone]
*[http://www.what-if.xkcd.com/129 Black hole moon]
*[http://www.what-if.xkcd.com/130 Snow removal]
*[http://www.what-if.xkcd.com/131 Microwaves]
*[http://www.what-if.xkcd.com/132 Hotter than average]
*[http://www.what-if.xkcd.com/133 Flagpole]
*[http://www.what-if.xkcd.com/134 Space burial]
*[http://www.what-if.xkcd.com/135 Digging downward]
*[http://www.what-if.xkcd.com/136 Spiders vs. the Sun]
*[http://www.what-if.xkcd.com/137 New Horizons]
*[http://www.what-if.xkcd.com/138 Jupiter Submarine]

[[Category:Meta]]

816: Applied Math

2015-09-14T03:11:32Z

108.162.217.17: /* Explanation */

{{comic
| number = 816
| date = November 8, 2010
| title = Applied Math
| image = applied_math.png
| titletext = Dear Reader: Enclosed is a check for ninety-eight cents. Using your work, I have proven that this equals the amount you requested.
}}

==Explanation==
{{w|Donald Knuth}} is a {{w|computer scientist}} who has written several computer science textbooks and he offers {{w|Knuth reward check|monetary rewards}} for anyone finding errors in his publications. The first error found in each book is worth US$2.56. Other suggestions are worth less than $2.56, but a check is still sent out if Dr. Knuth finds them to be reasonable.

[[Megan]] uses a proof to invalidate logic itself. According to the logic symbols [[File:contradiction.png]] at the bottom of the proof, she has proved that "the proposition (statement) is true and the proposition is false," i.e. "something is both true and false." (Specifically, ∴ means "therefore", ''P'' represents that a proposition is true, ∧ stands for "and", and an overbar negates a proposition (so ''P'' represents that a proposition is false)). If someone were to prove this, it would indeed derail the very foundation of logic and result in the {{w|principle of explosion}}, which is referenced in [[704: Principle of Explosion|a previous comic]].

Since most of the content of computer science textbooks is fundamentally based on logic, Megan's proof obviously spells doom for Dr. Knuth's, as each instance of logic can now be considered an error. After Megan's friend confirms the validity of her proof, Megan writes a letter to Dr. Knuth to collect her money for the 1,317,408 errors in {{w|The Art of Computer Programming}} at $2.56 each. According to the amount Megan demands as a reward, she apparently considers this textbook to have an average of more than 400 instances of logic per page (if she has the latest edition of each volume).

The title text is the reply from Dr. Knuth, in which he uses Megan's logic-disproving proof against her by claiming — with no logical explanation — that the amount of money she is in fact due as a reward is only 98 cents. He does this presumably to a) get out of paying her over three million dollars, b) demonstrate his contempt for or disbelief in her proof, and/or c) to show her, rather passive-aggressively, that she herself is not exempt from any ill effects resulting from her ridiculous proof. If logic is proved to be false, then all mathematics are proved false and 3,372,564.48 = 0.98.

The title of the comic, "Applied Math," is a play on {{w|Applied mathematics}}, "mathematical methods that are typically used in science, engineering, business, and industry," as opposed to {{w|pure math}}, which focuses exclusively on abstract concepts. Instead of using math to calculate something like the speed of a falling object, Megan uses it for an ostensibly more frivolous reason: to gain a huge reward via a proof of dubious validity.

==Transcript==
:[Ponytail is standing at a whiteboard considering a logical proof. The proof assumes ''P'' and deduces ''P'' ∧ ''P''.]
:Ponytail: Wow. I can't find fault with your proof.

:[Ponytail is still looking at the white board, the frame expands to show Megan walking away, rubbing her hands together in an evil manner.]
:Ponytail: You've show the inconsistency — and thus the invalidity — of basic logic itself.
:Megan: Excellent. On to step two...

:[Megan sits down at a desk and begins to write.]
:Dear Dr. Knuth,

:[She continues to write.]
:I am writing to collect from you the $3,372,564.48 I am owed for discovering 1,317,408 errors in ''The Art of Computer Programming...''

{{comic discussion}}
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Donald Knuth]]
[[Category:Logic]]