explain xkcd - User contributions [en]

2319: Large Number Formats

2020-06-13T10:31:41Z

162.158.202.160: /* Explanation */

{{comic
| number = 2319
| date = June 12, 2020
| title = Large Number Formats
| image = large number formats-2.png
| titletext = 10^13.4024: A person who has come back to numbers after a journey deep into some random theoretical field
}}

==Explanation==
{{incomplete|Created by ABRAHAM LINCOLN. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
This comic shows how different people express large numbers. This number in question is approximately the distance from the planet Earth to the planet Jupiter as of June 2020, in {{w|inch|inches}} (1 inch = 2.54 cm).

{| class="wikitable"
|-
! Number
! Type of person
! Notes
|-
| 25,259,974,097,204
| Normal Person
| This is the full number, written out in the normal fashion, with commas to indicate powers of 1000. Note that this convention is only considered normal in the Anglo-Saxon world; conventions for writing large numbers in full vary considerably across cultures. For example, in countries where the comma is used as a {{w|decimal separator}} (including Europe outside the UK), one would write the number as 25.259.974.097.204 (or 25'259'974'097'204 in Switzerland). Under the {{w|Indian numbering system}}, this number would be written as 25,25,997,40,97,204.
|-
| 25 Trillion
| Normal Person
| This is the number, rounded to trillions in the normal fashion.
|-
| 25 Billion
| Old British Person
| In current English usage, across the anglophonic world with some hold-outs, an n-illion means 10^(3n+3) as per the {{w|short scale}} system popularised by American influence in international trade, so a trillion means 10^12, as above. However, older British English use had an n-illion meaning 10^(6n) (i.e. the simpler calculation of ''million^n''), so a billion meant 10^12. The change stems from a 1974 commitment by Harold Wilson, the Prime Minister of the UK at the time, to change from the {{w|long scale}} (previously often described as the British system) to the short one for all official purposes.

Though not instantly widely adopted for common usage, the mid-'70s could therefore be considered the key turning point between when an older or younger British person learns (as the change filters through the system at various stages of education) what their "Billion"s and "Trillion"s are supposed to represent.

(The 1971 transition to decimalised currency may also date a person's experiences, but was a more comprehensive and immediate change for everyone who handled any money at all, in the UK, and thus was a more definite point of change apart from the extended survival of the "12 times table" being taught by rote in primary education, rather than ending at the 10s.)

As well as 'traditionalist' British use, the Long Scale is widely used in the non-anglophone world, in local language versions, though while the British system tended to infill n-and-a-half powers of the million with the term "thousand n-illion", the suffix "-illi''ard''", or equivalent, is often used for the thousands multiple directly atop the respective "-illion" point.
|-
|2.526x1013
|Scientist
|This number is formatted in {{w|scientific notation}}, using the exponent 1013.
|-
| 2.525997x1013
| Scientist trying to avoid rounding up
| Using as many decimal places as necessary until hitting a digit (0-4) that results in rounding down, even if it goes against the common scientific practice of reporting the correct amount of "significant figures". A previous version of the comic had a typo (the number was ''2.5997x1013''), but Randall updated the comic.
|-
| 2.526e13 or
2.526*10^13
| Software developer
| Computer code cannot typically use the superscripts or other types of rich text formatting, so the exponent is indicated with the {{w|caret}}. "e13" is {{w|Scientific notation#E notation|(scientific) E notation}} for the expression "10 raised to the power of 13".
|-
| 25,259,973,541,888
| Software developer who forgot about floats
| This is the number after being converted to the limited precision of a {{w|32-bit floating point|32-bit float}}.
|-
| 1013
| Astronomer
| For extremely large distances, astronomers typically only care about orders of magnitude, i.e. 1013, not 1012 or 1014. Randall often jokes about the lack of precision needed by astronomers, such as in that one xkcd (#[[2205]]) where the astronomer-cosmologist is equally willing to make pi equal to one, or ten. The original number is rounded to the nearest power of ten.
|-
| {∅,{∅},{∅,{∅}},{∅,{∅},{...
| Set theorist
| In {{w|Zermelo–Fraenkel set theory}}, the natural numbers are defined recursively by letting 0 = ∅ (the {{w|empty set}}), and ''n'' + 1 = ''n'' ∪ {''n''}. So, every natural number ''n'' is the set of all natural numbers less than ''n'', and since 0 is defined as the empty set, all numbers are nested sets of empty sets.
|-
| 1,262,998,704,860 score and four
| Abraham Lincoln
| In the {{W|Gettysburg Address}}, Lincoln speaks the number "87" as "four score and seven" ("score" meaning "20"). Here, the original number is rewritten in "score" (multiples of 20) plus a remainder (four).
|-
| 10^13.4024 ''(title text)''
| A person who has come back to numbers after a journey deep into some random theoretical field
| In some fields of mathematics, especially those dealing with very {{w|large numbers}}, numbers are sometimes represented by raising ten (or some other convenient base) to an oddly precise power, to facilitate comparison of their magnitudes without filling up pages upon pages of digits. An example of this is {{w|Skewes's number}}, which is formally calculated to be ''e''''e''''e''79, but is more commonly approximated as 10101034. 13.4024 is the {{w|common logarithm}} of 25,259,974,097,204 (log10 25,259,974,097,204 = 13.4024329009); thus, this "format" is still mathematically correct to use, but is not commonly used.
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[A panel only with text. At the top there is four lines of explanatory text. Below that there are 5 rows of number formats. There are 2 columns in each row. Each numerical format is in red, with black text explaining the format below it.]

:<big>What the way you write large</big>
:<big>numbers says about you</big>
:(Using the approximate current distance
:to Jupiter in inches as an example)

:[First row:]
:25,259,974,097,204
:Normal person
:25 trillion
:Normal person

:[Second row:]
:25 billion
:Old British person
:2.526x1013
:Scientist

:[Third row:]
:2.525997x1013
:Scientist trying to avoid rounding up
:2.526e13 or 2.526*10^13
:Software developer

:[Fourth row:]
:25,259,973,541,888
:Software developer who forgot about floats
:1013
:Astronomer

:[Fifth row:]
:{∅,{∅},{∅,{∅}},{∅,{∅},{...
:Set theorist
:1,262,998,704,860 score and four
:Abraham Lincoln

{{comic discussion}}
[[Category:Comics with color]]
[[Category: Programming]]
[[Category: Math]]
[[Category: Astronomy]]
[[Category: Science]]
[[Category:Comics featuring politicians]]

Talk:385: How it Works

2019-05-17T12:27:36Z

162.158.202.160:

Person who has questionable proficiency (at math in this case) makes gender-specific judgments society taught him to make. To be part of the whole you have to confirm to the stereotypes and labels placed upon you. You'll be forever alone otherwise. Sad story. I makes me cry, however, every time I recall that people who are good at math stereotyped as crazy mad evil egomaniacs who are forever alone. This is a catch 22 that's impossible to break. The title of the comics is "How it Works". And this is how it works.

I will admit, after I finished Calc 1, I came across this yet again via the random button, and kind of rolled my eyes. Then I read the title text, and this became one of my favorite comics. --[[Special:Contributions/140.198.42.64|140.198.42.64]] 00:19, 20 March 2013 (UTC)

:The same thing happened to me. This is definitely one comic where a little bit of knowledge about the subject really makes the joke. --[[Special:Contributions/108.162.215.125|108.162.215.125]] 06:59, 31 May 2016 (UTC)

This type of generalization also has a special name called "Stereotype threat". Research shows that women/girls who are good at math (identify as good at math) will do worse on hard math questions when they think (consciously or unconsciously) that her own personal failings will reflect on the negative stereotype. (Real example: a group of professors asked SAT testing body to ask for demographic questions (gender/race) after the test instead of before.) [[Special:Contributions/108.162.254.107|108.162.254.107]] 04:15, 18 June 2014 (UTC)

I don't really think that pi + C is different from just C. Pi is a constant anyway! {{unsigned ip|173.245.48.96}}

In popular culture: it appeared twice in the grade 10 english module in the philippines,and without the correct citation. p.s. what should i do? [[Special:Contributions/108.162.215.10|108.162.215.10]] 08:33, 16 July 2015 (UTC)
:xkcd is released under a Creative Commons license that allows any redistribution but requests a citation if you are making money from it. I think it's fine unless they're ripping Randall off. [[User:Jacky720|That's right, Jacky720 just signed this]] ([[User talk:Jacky720|talk]] | [[Special:Contributions/Jacky720|contribs]]) 23:53, 5 May 2018 (UTC)
::''reads license'' okay, no commercial redistribution, and give appropriate credit. Ask them nicely to add a citation? Idk. [[User:Jacky720|That's right, Jacky720 just signed this]] ([[User talk:Jacky720|talk]] | [[Special:Contributions/Jacky720|contribs]]) 23:57, 5 May 2018 (UTC)

Maybe include the phrase confirmation bias?[[Special:Contributions/108.162.218.53|108.162.218.53]] 20:27, 21 February 2016 (UTC)

Megan wasn't finished with the equation yet. That's why her hand is still up at the board. She can still produce a correct - even if strange - equation. {{unsigned ip|162.158.90.189}}
:So is the hand of the second cueball.

One thing I noticed is if you just take the letters of "Pi" and "c", it makes "Pic". "Pic" is a way to shorten the word "Picture"![[Special:Contributions/108.162.245.115|108.162.245.115]] 18:30, 27 September 2016 (UTC)

Talk:385: How it Works

2019-05-17T12:26:43Z

162.158.202.160:

Person who has questionable proficiency (at math in this case) makes gender-specific judgments society taught him to make. To be part of the whole you have to confirm to the stereotypes and labels placed upon you. You'll be forever alone otherwise. Sad story. I makes me cry, however, every time I recall that people who are good at math stereotyped as crazy mad evil egomaniacs who are forever alone. This is a catch 22 that's impossible to break. The title of the comics is "How it Works". And this is how it works.

I will admit, after I finished Calc 1, I came across this yet again via the random button, and kind of rolled my eyes. Then I read the title text, and this became one of my favorite comics. --[[Special:Contributions/140.198.42.64|140.198.42.64]] 00:19, 20 March 2013 (UTC)

:The same thing happened to me. This is definitely one comic where a little bit of knowledge about the subject really makes the joke. --[[Special:Contributions/108.162.215.125|108.162.215.125]] 06:59, 31 May 2016 (UTC)

This type of generalization also has a special name called "Stereotype threat". Research shows that women/girls who are good at math (identify as good at math) will do worse on hard math questions when they think (consciously or unconsciously) that her own personal failings will reflect on the negative stereotype. (Real example: a group of professors asked SAT testing body to ask for demographic questions (gender/race) after the test instead of before.) [[Special:Contributions/108.162.254.107|108.162.254.107]] 04:15, 18 June 2014 (UTC)

I don't really think that pi + C is different from just C. Pi is a constant anyway! {{unsigned ip|173.245.48.96}}

In popular culture: it appeared twice in the grade 10 english module in the philippines,and without the correct citation. p.s. what should i do? [[Special:Contributions/108.162.215.10|108.162.215.10]] 08:33, 16 July 2015 (UTC)
:xkcd is released under a Creative Commons license that allows any redistribution but requests a citation if you are making money from it. I think it's fine unless they're ripping Randall off. [[User:Jacky720|That's right, Jacky720 just signed this]] ([[User talk:Jacky720|talk]] | [[Special:Contributions/Jacky720|contribs]]) 23:53, 5 May 2018 (UTC)
::''reads license'' okay, no commercial redistribution, and give appropriate credit. Ask them nicely to add a citation? Idk. [[User:Jacky720|That's right, Jacky720 just signed this]] ([[User talk:Jacky720|talk]] | [[Special:Contributions/Jacky720|contribs]]) 23:57, 5 May 2018 (UTC)

Maybe include the phrase confirmation bias?[[Special:Contributions/108.162.218.53|108.162.218.53]] 20:27, 21 February 2016 (UTC)

Megan wasn't finished with the equation yet. That's why her hand is still up at the board. She can still produce a correct - even if strange - equation. {{unsigned ip|162.158.90.189}}

> So is the hand of the second cueball.

One thing I noticed is if you just take the letters of "Pi" and "c", it makes "Pic". "Pic" is a way to shorten the word "Picture"![[Special:Contributions/108.162.245.115|108.162.245.115]] 18:30, 27 September 2016 (UTC)

Talk:385: How it Works

2019-05-17T12:26:04Z

162.158.202.160:

Person who has questionable proficiency (at math in this case) makes gender-specific judgments society taught him to make. To be part of the whole you have to confirm to the stereotypes and labels placed upon you. You'll be forever alone otherwise. Sad story. I makes me cry, however, every time I recall that people who are good at math stereotyped as crazy mad evil egomaniacs who are forever alone. This is a catch 22 that's impossible to break. The title of the comics is "How it Works". And this is how it works.

I will admit, after I finished Calc 1, I came across this yet again via the random button, and kind of rolled my eyes. Then I read the title text, and this became one of my favorite comics. --[[Special:Contributions/140.198.42.64|140.198.42.64]] 00:19, 20 March 2013 (UTC)

:The same thing happened to me. This is definitely one comic where a little bit of knowledge about the subject really makes the joke. --[[Special:Contributions/108.162.215.125|108.162.215.125]] 06:59, 31 May 2016 (UTC)

This type of generalization also has a special name called "Stereotype threat". Research shows that women/girls who are good at math (identify as good at math) will do worse on hard math questions when they think (consciously or unconsciously) that her own personal failings will reflect on the negative stereotype. (Real example: a group of professors asked SAT testing body to ask for demographic questions (gender/race) after the test instead of before.) [[Special:Contributions/108.162.254.107|108.162.254.107]] 04:15, 18 June 2014 (UTC)

I don't really think that pi + C is different from just C. Pi is a constant anyway! {{unsigned ip|173.245.48.96}}

In popular culture: it appeared twice in the grade 10 english module in the philippines,and without the correct citation. p.s. what should i do? [[Special:Contributions/108.162.215.10|108.162.215.10]] 08:33, 16 July 2015 (UTC)
:xkcd is released under a Creative Commons license that allows any redistribution but requests a citation if you are making money from it. I think it's fine unless they're ripping Randall off. [[User:Jacky720|That's right, Jacky720 just signed this]] ([[User talk:Jacky720|talk]] | [[Special:Contributions/Jacky720|contribs]]) 23:53, 5 May 2018 (UTC)
::''reads license'' okay, no commercial redistribution, and give appropriate credit. Ask them nicely to add a citation? Idk. [[User:Jacky720|That's right, Jacky720 just signed this]] ([[User talk:Jacky720|talk]] | [[Special:Contributions/Jacky720|contribs]]) 23:57, 5 May 2018 (UTC)

Maybe include the phrase confirmation bias?[[Special:Contributions/108.162.218.53|108.162.218.53]] 20:27, 21 February 2016 (UTC)

Megan wasn't finished with the equation yet. That's why her hand is still up at the board. She can still produce a correct - even if strange - equation. {{unsigned ip|162.158.90.189}}
>So is the hand of the second cueball.

One thing I noticed is if you just take the letters of "Pi" and "c", it makes "Pic". "Pic" is a way to shorten the word "Picture"![[Special:Contributions/108.162.245.115|108.162.245.115]] 18:30, 27 September 2016 (UTC)

Talk:1920: Emoji Sports

2017-11-24T08:53:26Z

162.158.202.160: edible candle

It seems like in addition to the destructive sports thing, he's also playing on the emojis made from other emojis in multi character Unicode, but as it's 3 in the morning and I can't even remember what things are called I'm not gonna even try to edit right now. [[Special:Contributions/162.158.62.33|162.158.62.33]] 07:50, 24 November 2017 (UTC)

Hey! An early published comic! 3AM Me And Randall time Thursday night right now. Fun since I only read on Monday and Thursday nights. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 08:14, 24 November 2017 (UTC)

Actually candle eating isn't so far out there: https://www.youtube.com/watch?v=jXg3l_Lnmdo

Talk:1063: Kill Hitler

2017-11-09T21:50:46Z

162.158.202.160: You are all assuming that the time machine actually works. Why? ~~~~

Actually, I think the joke here is that Black Hat actually did end Hitler's atrocities, but that history is not actually changeable. Hitler's "suicide" was actually Black Hat killing him. This is then layers with the impossibility of changing history. This would imply that anyone that wants to stop Hitler before he rose to power will be circumvented.

[[User:UnaSalusVictis|UnaSalusVictis]] ([[User talk:UnaSalusVictis|talk]]) 01:26, 25 November 2012 (UTC)UnaSalusVictis

:According to all reasonable time travel theories, this makes sense. You cannot go into the past to change things, because the future that exists is a future where you were in the past - you just didn't know it yet because it was in your future. This also applies to the future. Your knowledge of the future cannot possibly change it because your foreknowledge exists in this future. If your foreknowledge made that future not happen, then there would be no need to change it. But the future and the past account for the fact that you were there to change things, even before you ever knew you would be. Ergo, any attempt to ''change'' the past will merely result in ''causing'' the past to result exactly as it did before. The catch-22 of time travel stories. You can have a fatal flaw, or a fatally uncompelling story. But, all that said, this is a cartoon and not necessarily reliant on reasonable time travel theory.[[Special:Contributions/76.29.225.28|76.29.225.28]] 07:07, 23 June 2013 (UTC)

:That's exactly my opinion on this topic! Look at this video (Mercedes vs Hitler in the past): [[https://www.youtube.com/watch?v=ytVdBLMmRno]] ~~Muessigb
::But say you could predict what the future would look like if you did nothing (or did not yet have that knowledge). Then by obtaining that knowledge you could then do something you would not have done otherwise and thus change the potential future. With a powerful enough simulator, you might get a good idea of what would happen if no one knew about it, and then decide if something should be changed based on this information. This is what happens in the book {{w|Lightning (novel)|Lightning}}. I do not believe this can be done, but as the future has not happened yet, I do not see the same problems as with traveling back in time. Of course having a good guess of the future is not the same as traveling to it... If you did that, then changing it after you had been there would be troublesome. See for instance {{w|Back to the Future 2}} and the book mentioned above. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:44, 6 January 2016 (UTC)

True, killing Hitler before he rose to power and committed all his atrocities would cause a Grandfather paradox... Cueball invented the time machine and send Black Hat back because he wanted Hitler dead, but if Hitler died before that, there would be no reason to invent the time machine and send Black Hat back which ergo cause the initial trip to kill Hitler not possible and ergo Hitler couldn't die before he rises to power and committed his atrocities. [[Special:Contributions/175.137.100.81|175.137.100.81]] 01:40, 5 December 2012 (UTC)
:Just for the record, it was Black Hat who invented this time machine! --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:51, 6 January 2016 (UTC)

Maybe in the original timeline, Hitler's atrocities extended beyond 1945. When Black Hat went back in time and assassinated Hitler in 1945, a new time-line was created. When Black Hat returned to the current date, he returned to a different timeline than the one he left. In this timeline (ours), Hitler died in 1945, and because this timeline is based on that fact, Cueball thinks that Black Hat has not changed anything, when in fact, Black Hat's actions created the new timeline. -- mwburden [[Special:Contributions/70.91.188.49|70.91.188.49]] 15:00, 7 December 2012 (UTC)
:Except that Hitler would have already been killed in 1945 by Black Hat, only it would have been thought beforehand to be Hitler killing himself as, until the time machine is invented, you wouldn't think that people from the future would be coming from the future to assassinate the opponent. People would assume that Hitler killed himself as that is more plausible than an assassin killing him and then vanishing without a trace. {{unsigned|Mulan15262}}
::Also Cueball would not know that anything had happened if anything had been changed, as his an everyone else life would have changed, and most people born say a few years after the start of the way, would probably not have been born, because everyone else would have done something different if World War II had never happened, and many more people would have lived back then, to make the chance that your parents meet and fall in love much less. And even if they still did, they might have had their children at a different time in their lives! And just a few seconds can matter in which cell will enter the egg...--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:51, 6 January 2016 (UTC)

:The only flaw in that logic is that there's really no way Hitler would have survived the Russian invasion. He was in a bunker, killing himself, because his whole nation and army were crushed. He would have been put on trial and no doubt executed, if not shot by the first soldier who saw him. -HavokTheorem [[Special:Contributions/121.73.107.90|121.73.107.90]] 04:30, 9 October 2013 (UTC)
::Thank you for this answer. My faith in explainxkcd contributors was declining rapidly until I reached your comment. [[Special:Contributions/108.162.219.58|108.162.219.58]] 20:20, 30 January 2014 (UTC)
::Actually you only think that because Black Hat prevented [http://vignette4.wikia.nocookie.net/wolfenstein/images/d/d7/Hitler2forms.gif/revision/latest?cb=20090918003616 Mecha Hitler]. [[Special:Contributions/162.158.255.80|162.158.255.80]] 17:54, 16 December 2015 (UTC)

Was the explanation always as bad as it appears now?? It's awful. [[Special:Contributions/108.162.219.58|108.162.219.58]] 01:34, 1 February 2014 (UTC)

First off, in a previous time line he could have escaped to a Moon Base to rebuild his army and destroy the world and Cueball just does not remember that history, just the one where Hitler dies in the bunker. Second, there are many forms of logical time travel. You could jump to a different Now 70 years ago and kill Hitler (assuming he exists) and then come back. Your timeline would not have changed, but the other Now would have a future without Hitler. The good or bad that is achieved is the same, but you get no benefit other then the joy of killing Hitler. And you really should seek professional help for that.--[[Special:Contributions/108.162.219.18|108.162.219.18]] 18:52, 20 May 2014 (UTC)
:In many stories where this idea is used, you actually go to this alternative time yourself, so when you return the world you return to would be the one where Hitler died. Maybe you were never born in this world, but as you are from another dimension where you did get born, then you can exist in this world instead. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 12:51, 6 January 2016 (UTC)

Did Randall at least partly choose Hitler because of the old rumour that he wasn't actually dead (Because hearing the news of his death may have seemed incredulous, and because his body was removed by the Soviets, who never openly revealed information to the West). Sorry about the wordiness of this comment, I hope you'll be able to comprehend it. {{unsigned ip|108.162.250.223}}

:I recommend this short story on time travel: [http://www.abyssapexzine.com/wikihistory/ Wikihistory]. My favourite quote: "everybody kills Hitler on their first trip". Brilliant, short and nerdy.
:--[[User:Lou Crazy|Lou Crazy]] ([[User talk:Lou Crazy|talk]]) 16:37, 28 September 2015 (UTC)

You are all assuming that the time machine actually works. Why? [[Special:Contributions/162.158.202.160|162.158.202.160]] 21:50, 9 November 2017 (UTC)

1061: EST

2017-11-09T21:44:30Z

162.158.202.160: /* Other features */ spelling or meaning, whichever

{{comic
| number = 1061
| date = May 28, 2012
| title = EST
| image = est.png
| titletext = The month names are the same, except that the fourth month only has the name 'April' in even-numbered years, and is otherwise unnamed.
}}

==Explanation==
This comic pokes fun of attempts to "fix" the calendar by making it simpler or more rational, which inevitably result in a system just as complicated. This is an example of the paradox in complexity theory that if you attempt to simplify a system of problems by creating a new system of evaluation for the problems you often have instead made the problem more complex than it was originally.

[[Randall]] advertises his idea for a "Universal Calendar for a Universal Planet". He combines {{w|calendar#Calendars in use|calendar}} definitions with {{w|Time zone|time zone}} definitions. The abbreviation '''EST''' in this comic stands for ''Earth Standard Time'' (hence the title), but it is in itself a joke on the American {{w|Eastern Time Zone|Eastern Standard Time}}. In the rest of the explanation EST refers to the comic's Earth Standard Time!

===Length of year===
Because there are approximately 365.2422 days in a {{w|solar year}}, various calendars use different means to keep the calendar year in sync with the solar year and the seasons. The Julian Calendar, for example, has leap days every four years, giving it an average year length of 365.25 days. The most widely used system is the {{w|Gregorian Calendar|Gregorian Calendar}}, which also has leap days every four years, but skips leap days in years divisible by 100 unless the year is also divisible by 400, the latter additions come from Earth's {{w|axial precession}}. This gives it an average year length of 365.2425 days, which is very close to the length of a solar year (see detailed explanation in this video: ''[https://www.youtube.com/watch?v=82p-DYgGFjI Earth's motion around the Sun, not as simple as I thought]''.

{{w|Calendar reform|Other calendars}} have been proposed, such not counting leap days and special "festival days" as a day of the week, in order to make every date fall on the same day of the week every year.

*At "24 hours 4 minutes", EST days are longer, though there are only 360 of them in the year. The extra 4 minutes over the course of 360 days adds up to one standard day, so Randall's EST calendar would at this point have a year that is 361 standard days long. The 24 hours plus 4 minutes length may be a reference to {{w|sidereal day}}, whose duration is 24 hours ''minus'' 4 minutes.

*Running the clock backwards for 4 hours after every full moon gives 8 additional hours at each full moon, twelve or thirteen times in a year. Because a thirteenth full moon will occur once every 2.7 solar years on average, this modification adds 4.1228 standard days to an EST year, bringing it to 365.1228 days.

*The doubling of the non-prime numbers of the first non-reversed hour after each solstice and equinox is a final, very complicated way to bring Randall's EST year in extremely close sync with the solar year. There are 17 prime numbers between 0 and 59 and 43 non-primes. There are 2 equinoxes and 2 solstices each year, so a total of 4x43 = 172 minutes will occur twice. This brings the average length of Randall's EST year to 365.2422 standard days, equal to the solar year to four decimal places.

===Claimed benefits===
Many of the claimed benefits for the calendar are highly dubious:
*While it is fairly ''simple'' to describe, EST is far from simple to understand or put in practice. Clocks in particular would have to regularly undertake very complicated processes like running backwards or duplicating non-prime minutes.
*EST does appear to be fairly ''clearly defined''.
*EST fails completely to be ''unambiguous''. Following each full moon, four hours occur three times, twice forward and once backward. Several minutes are also duplicated, making times during those periods ambiguous.
*The only way EST is ''free of historical baggage'' is that it breaks free of any sensible bits of historical baggage; it keeps such things as the 30-day month and 12-month year, but adopts a different (and variable) length of day that would make it wildly out of sync with the Earth's day-night cycle.
*EST is ''compatible with old units'', as far as seconds, minutes, and hours are concerned, though not for days, months, or years.
*EST is indeed very ''precisely synced with the solar cycle''. The joke is that this has nothing to do with the day/night cycle or the Earth's yearly orbital cycle; the {{w|solar cycle}} is a period of magnetic fluctuation within the sun, lasting 11 Earth years.
*EST is ''free of leap years'', though some EST years are 8 hours longer than others on account of having an extra full moon.
*A calendar ''amenable to date math'' makes it easy to find the length of time between two dates and times by having standardized periods of time. The complex variability of the length of EST years, days, and hours mean it is only ''intermittently'' amenable to date math, which is to say not at all.

===Other features===
The features of the calendar get increasingly bizarre as the description proceeds:

*The {{w|Epoch (reference date)|Epoch}} for EST is set by reference to the {{w|Julian calendar}}, which was superseded by the {{w|Gregorian calendar}}. The Julian calendar is currently 13 days behind the Gregorian calendar.

*The different zone for the United Kingdom is a reference to 1 yard being equal to 0.9144 meters, a pun on using {{w|imperial units}} instead of the {{w|metric system}}. This has been the joke before in [[526: Converting to Metric]] and is also mentioned in [[1643: Degrees]].

*Randall does not like {{w|Daylight saving time}} (DST) very much, as has been made clear in [[:Category:Daylight saving time|several comics]] both before and after this one. See Narnian time below.

*Narnian time is a reference to the fictitious world of {{w|Narnia (world)|Narnia}} in {{w|CS Lewis|CS Lewis'}} book {{w|The Lion, The Witch and The Wardrobe}} and its sequels. In Narnia, time passes much more quickly than in the real world. You could be in Narnia for several days and only a few minutes would have passed in the real world. However, synchronizing this effect would be impossible because it is not a consistent rate; it fluctuates wildly based on the whims of drama and magic. This and the DST mentioned above should be seen as a pair. Because when a country goes into DST time may not pass, which is basically what happens (more or less) when a child enters into Narnia. Whereas in EST Narnian time is synchronized to normal time, which DST is but for the one hour difference in the real calender. Using the weird Narnian time was used as the plot in the bottom left drawing in [[821: Five-Minute Comics: Part 3]].

*The Gregorian calendar does not include the year "0"; after "1" BC the next year is "1" AD. Randall's invention fixes this according to correct Mathematics, only to reintroduce the problem immediately by arbitrarily omitting the year 1958. The year 1958 is significant because January 1, 1958 is the epoch (time zero) in {{w|International Atomic Time}} (TAI), which is part of the basis for {{w|Coordinated Universal Time}} (UTC). (The main difference is that TAI doesn't add leap seconds.)

*The title text's concept of only naming the fourth month ''April'' in the even numbered years, and then leave it unnamed the other years, may be a reference to the ancient (Pre-Babylonian Exile) [http://www.jewfaq.org/calendar.htm Jewish Calendar], which did not name the months, rather assigning them numbers from 1 to 12 (or 13 in leap years, where an extra month was added instead of an extra day). The names used by Jews today are the names of the Babylonian months, derived from various Babylonian deities or events in Jewish history or on the calendar.

==Transcript==
:[Caption and text above the main panel:]
:xkcd presents
:<big>Earth Standard Time</big>
:(EST)
:A universal calendar for a universal planet
:EST is...
:Simple • Clearly defined • Unambiguous
:Free of historical baggage • Compatible with old units
:Precisely synced with the solar cycle • Free of leap years
:Intermittently amenable to date math

:[A list of the details concerning EST:]
:Units
:{|
|-
| style="text-align:right;" | Second:
| 1 S.I. second
|-
| style="text-align:right;" | Minute:
| 60 seconds
|-
| style="text-align:right;" | Hour:
| 60 minutes
|-
| style="text-align:right;" | Day:
| 1444 minutes (24 hours 4 minutes)
|-
| style="text-align:right;" | Month:
| 30 Days
|-
| style="text-align:right;" | Year:
| 12 months
|}

:Rules
:For 4 hours after every full moon, run clocks backward.
:The non-prime-numbered minutes of the first full non-reversed hour after a solstice or equinox happen twice.

:{|
|-
| style="text-align:right;" | Epoch
|    
| Time Zones
|-
| style="text-align:right;" | 00:00:00 EST
|
| The two EST time zones are
|-
| style="text-align:right;" | January 1, 1970 = 00:00:00 GMT
|
|   ''EST'' and ''EST (United Kingdom)''
|-
| style="text-align:right;" | January 1, 1970 (Julian calendar)
|
| These are the same except that the UK second is 0.9144 standard seconds
|}

:{|
|-
| style="text-align:right;" | Daylight saving:
| Countries may enter DST, but no time may pass there.
|-
| style="text-align:right;" | Narnian Time:
| Synchronized✔
|-
| style="text-align:right;" | Year Zero:
| EST ''does'' have a year 0. (However, there is no 1958.)
|}

{{comic discussion}}

[[Category:Time]]
[[Category:Daylight saving time]]
[[Category:Astronomy]]

Talk:1845: State Word Map

2017-06-02T14:17:39Z

162.158.202.160:

New Hampshire and Maine are merged together? Significance? [[User:JohnHawkinson|JohnHawkinson]] ([[User talk:JohnHawkinson|talk]]) 04:19, 2 June 2017 (UTC)
: That's weird, because there're definitely 50 words. Am I overlooking something... [[User:PvOberstein|PvOberstein]] ([[User talk:PvOberstein|talk]]) 04:22, 2 June 2017 (UTC)
:: Well, there are two words assigned to the merged state. It's just that the political boundary line is missing. [[User:JohnHawkinson|JohnHawkinson]] ([[User talk:JohnHawkinson|talk]]) 04:26, 2 June 2017 (UTC)
::: Oh, duh. [[User:PvOberstein|PvOberstein]] ([[User talk:PvOberstein|talk]]) 04:54, 2 June 2017 (UTC)
::::Added trivia about Randall's error. Wonder if he will spot it and correct it later?--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 13:10, 2 June 2017 (UTC)

"The comic continues to make fun of Florida in the title text by saying that Florida searches for sex porn instead of porn, when porn is already about sex." [https://www.reddit.com/r/EarthPorn/ But is it really, though?] [[Special:Contributions/108.162.212.59|108.162.212.59]] 05:40, 2 June 2017 (UTC)

The misspelling map reference is clear, but the first thing I thought of was all the conclusions in the recently published book [https://www.amazon.com/dp/B01AFXZ2F4/ref=cm_sw_r_cp_awdb_qqqmzbRKZY0X0 Everybody Lies] about people's real opinions and desires drawn from Google data. [[Special:Contributions/108.162.246.107|108.162.246.107]] 06:27, 2 June 2017 (UTC)

The word "porn" has become slightly more generic than that in informal speech. See eg. Scenery Porn on TVTropes. So, searching for "sex porn" is probably mostly redundant, but not necessarily completely so. --[[Special:Contributions/162.158.92.148|162.158.92.148]] 13:16, 2 June 2017 (UTC)

As a non-native speaker and also someone who failed statistics: how is distinctive e.g. with the syphilis thing different from most? should this be explained more? [[Special:Contributions/162.158.202.160|162.158.202.160]]

Talk:1820: Security Advice

2017-04-05T20:14:38Z

162.158.202.160:

Secret questions are not 2-factor authentication (2FA). They are just a really shitty password, something that you know. --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 14:33, 5 April 2017 (UTC)

Secret questions are more like 0-factor authentication, since they typically ask for public data. Shirluban [[Special:Contributions/141.101.88.106|141.101.88.106]] 14:39, 5 April 2017 (UTC)

Even when it isn't public it is often very unsecure - like: "your password has to have upper and lower case letters, numbers" and other requirements - if you forget it just enter the brand of your first car, there are about 20 likely answers (make it 40 if you need to additionally see wether or not it has been capitalized) [[Special:Contributions/162.158.92.46|162.158.92.46]] 15:18, 5 April 2017 (UTC)

Use prime numbers in your password: this would only limit the number of possible passwords for a hacker to check.

Use special characters like & and % : this advice is thoroughly handled in https://xkcd.com/936/ Changing characters into a special one does adds just very little to the search space.
However, a video from Computerphile suggests ''inserting'' a random character somewhere in the password which might actually be rather helpful

[[Special:Contributions/162.158.111.211|162.158.111.211]] 14:53, 5 April 2017 (UTC)

Maybe you really should use a secure font [https://technet.microsoft.com/library/security/MS15-078 Font related bug] [[Special:Contributions/162.158.79.161|162.158.79.161]] 15:13, 5 April 2017 (UTC)

Should the blue check mark tip be noted as only being useful on Twitter? Usually, the advice doesn't apply to emails, which are significantly more likely to ask for your less-secret account details, but also significantly less likely to have a blue check mark. [[Special:Contributions/162.158.2.10|162.158.2.10]] 15:15, 5 April 2017 (UTC)

"If a border guard asks to examine your laptop, you have a legal right to challenge them to a chess game for your soul.", do any of you know exactly what is the original advice here? This is probably different in different countries, but if I recall correctly you can't prevent them from seizing your device, but you are not required to provide them your passwords (but they may give you a hard time or deny your entry if you are not a citizen). Anyone can confirm this? [[Special:Contributions/108.162.216.22|108.162.216.22]] 15:16, 5 April 2017 (UTC)

The rice trick doesn't even work for wet phones. http://www.gazelle.com/thehorn/wp-content/uploads/2014/05/Water-Damage-Prevention-and-Recovery.pdf [[Special:Contributions/162.158.111.211|162.158.111.211]] 15:33, 5 April 2017 (UTC)

:Yeah - beat me to it! The rice trick doesn't work...not for phones or anything else for that matter. So this is double bad advice. [[Special:Contributions/162.158.69.39|162.158.69.39]] 16:06, 5 April 2017 (UTC)

Border guard - I'd like to see a bit more explanation, please, on how Ingmar Berman's film shows a man playing chess with Death, and possibly the infamous subversion of this trope in Bill And Ted's Bogus Journey. As it is, the explanation is only the ''bare bones''. --[[Special:Contributions/172.68.34.52|172.68.34.52]] 17:35, 5 April 2017 (UTC)

Checking the padlock icon in your browser is not enough to make sure you're really connected to the site you think. You have to check the domain too, to make sure you're not on a typosquatter domain (e.g. explianxkcd.com instead of explainxkcd.com). For really important thing like banking, you should check for an Extended Validation Certificate (Firefox shows the name of the organization running the website beside the padlock to indicate an EV-Certificate). This means, that the CA checked if the website operator really is who he pretends to be (and take a hefty sum of money for the process). Yeah, i know, security isn't easy. Using the brain still can't be replaced. --[[Special:Contributions/162.158.202.160|162.158.202.160]] 20:14, 5 April 2017 (UTC)