explain xkcd - User contributions [en]

Talk:1292: Pi vs. Tau

2024-09-26T23:43:39Z

141.101.99.27: Undo revision 351442 by 172.70.86.227 (talk) CG's guilty conscience...

It should be known that in the tabletop miniatures game Warhammer 40k, the Tau are a race of technologically advanced humanoids, although I would be surprised if this has any meaning in relation to the comic.

[[Special:Contributions/162.158.74.247|162.158.74.247]] 18:44, 14 December 2020 (UTC)

Pau is somewhat less conveniently, but more accurately, approximated as (401-sqrt(2)*phi)/200.

I started an explanation. Hopefully others will help improve it, as I don't think it's quite adequate. [[Special:Contributions/199.27.130.174|199.27.130.174]] 05:32, 18 November 2013 (UTC)

The comic currently shows the symbol π (pi) in all three cases, but it should have the symbol τ (tau) in the rightmost case. I'm sure there is a compromise symbol "pau" too. Maybe with a deformed left leg? [[Special:Contributions/141.101.97.4|141.101.97.4]] 07:07, 18 November 2013 (UTC)

WolframAlpha gives
<pre>
4.5545743763144164456766617143366171162404440766665105335330776311513504520604364524762740226212061363100001776216741750712622557020442741544760057441760026766230424023460366047331305225241275347777145543054127636365666430221066167347236617261603127725745513663702031155234027041040155322217227723576660045156156303357534162372112340027743775672417274565277274565735325624457113522164166560115654407251403563246444122664066521461311773474046032763760765740133706761276420415672577471077133607673035331070364705651055376634161405567176532346433567731715723623721267302576735154761375545411215522177775706407470673020025353246535120744232706060324711633457720155013202527060250466252665661576165164140301645132275526153126363575631176312270212441433434206352313125326760006365710744276056412434626534152021052065172556442150110056601034116570607064550553636566432544260105637423220411372664024454234201642615033200331506013362432026775605543212342336511350621361642654426372425415023071413764173735461042064323757413414533013..._8</pre> which does indeed have four 666 sequences. [[Special:Contributions/141.101.99.254|141.101.99.254]] 08:06, 18 November 2013 (UTC)
This number contains 7777, 000 and 444 twice, though. [[Special:Contributions/141.101.93.11|141.101.93.11]] 09:08, 18 November 2013 (UTC)

Wrote the transcript, not sure if I explained the visual well enough, so I left the incomplete tag if someone else has a better idea. Should suffice for understanding however, considering the content [[Special:Contributions/108.162.248.18|108.162.248.18]] 08:55, 18 November 2013 (UTC)

----

People should be made aware that pau is a slang for dick in Portuguese. {{unsigned ip|188.114.98.34}}

(The discussion about different results was trimmed)

Wolfram gives the result with 666

http://www.wolframalpha.com/input/?i=1.5+pi+octal
<pre>
4.554574376314416445676661714336617116240444076666510533533077631151350452060436452476274022621206136310000177621674175071262255702044274154476005744176002676623042402346036604733130522524127534777714554305412763636566643022
</pre>
The Unix arbitrary precision calculator gives the result without

$ echo "scale=200; obase=8; 6*a(1)" | bc -l
<pre>
4.554574376314416443236234514475050122425471573015650314763354527003043167712611655054674757031331252340351471657646433317273112431020107644727072362457372164022043765215506554422014311615574251563446213636251744101107770257
</pre>
Any suggestions how we can check them?

"Randall says so" is probably correct, but insufficient :-) {{unsigned|Mike}}

:Please use the <nowiki><pre></nowiki> tag for this long numbers.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 09:20, 18 November 2013 (UTC)

Testing Wolfram Alpha with <pre>4.55457437631441644567666171433661711624044407666651053353307763115135045206043645247627402262120613631000177621674175071262255_8 in decimal</pre> and <pre>4.55457437631441644567666171433661711624044407666651053353307763115135045206043645247627402262120613631000_8 in decimal</pre> both indicate the approximation is only accurate to a limited degree.
<pre>
http://www.wolframalpha.com/input/?i=4.55457437631441644567666171433661711624044407666651053353307763115135045206043645247627402262120613631000177621674175071262255_8+in+decimal
</pre>
<pre>
http://www.wolframalpha.com/input/?i=4.55457437631441644567666171433661711624044407666651053353307763115135045206043645247627402262120613631000177621674175071262255_8+in+decimal
</pre>

The method I used to get the value I put in the text was; I used the following command to generate my approximation:
<pre>echo 'scale=200; obase=8; a(1) * 6' | bc -l | tr -d ' \\\n' ; echo</pre> which outputs<pre>
4.554574376314416443236234514475050122425471573015650314763354527003043167712611655054674757031331252340351471657646433317273112431020107644727072362457372164022043765215506554422014311615574251563446213636251744101107770257
</pre>
In 'bc'', a(1) is arctangent of 1 (i.e. 45 degrees, or pi/4); (pi/4 * 6) should be equal to 'pau'. I additionally checked the result using base 2 encoding, and converted each three bit binary value into an octal value. The decimal value of pi (using a(1) * 4) matches with the value of pi to at lease 1000 digits.
[[Special:Contributions/173.245.54.86|173.245.54.86]] 09:21, 18 November 2013 (UTC)

Both Maxima and the GNU Emacs calculator output as the first 1000 octal digits:
<pre>
4.5545743763144164432362345144750501224254715730156503147633545270030431677126116550546747570313312523403514716576464333172731124310201076447270723624573721640220437652155065544220143116155742515634462136362517441011077702611156024117447125224176203716336742057353303216470257662666744627534325504334506002730517102547504145216661211250027531716641276765735563341721214013553453654106045245066401141437740626707757305450703606440651111775270032710035521352101513622062164457304326450524432531652666626042202562202550566425643040556365710250031642467447605663240661743600041052212627767073277600402572027316222345356036301002572541750000114422036312122341474267232761775450071652613627306745074150251171507720277250030270442257106542456441722455345340370205646442156334125564557520336340223313312556634450170626417234376702443117031135045420165467426237454754566012204316130023063506430063362203021262434464410604275224606523356702572610031171344411766505734615256121034660773306140032365326415773227551
</pre>
This also agrees with the first 220 digits of the previous result (last two digits above are 57 vs 61 here, maybe due to rounding when converting to octal). Again, no 666 within the first 200 digits. The Wolfram result deviates from this at the 18th digit already. --[[User:Ulm|ulm]] ([[User talk:Ulm|talk]]) 10:21, 18 November 2013 (UTC)

Also e+2 does not contain the substring '666':
<pre>echo "scale=200; obase=8; e(1) + 2" | bc -l</pre>
<pre>4.55760521305053551246527734254200471723636166134705407470551551265170233101050620637674622347347044466373713722774330661414353543664033100253542141365517370755272577262541110317650765740633550205306625</pre>--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 10:43, 18 November 2013 (UTC)

: A sudden flash of realization: are we getting nerd-sniped here?--[[Special:Contributions/108.162.254.168|108.162.254.168]] 11:55, 18 November 2013 (UTC)

::Not unlikely. Have posted this as a trivia. [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 20:11, 23 November 2013 (UTC)

: The claim is clearly about e+2, making Dgbrt's comment closest to the right direction. [[Special:Contributions/173.245.54.40|173.245.54.40]] 12:03, 18 November 2013 (UTC)

When I take Wolfram alpha's octal(pi*1.5) I get the first 303 (base 10) characters as this:
<pre>
4.554574376314416445676661714336617116240444076666510533533077631151350452060436452476274022621206136310000177621674175071262255702044274154476005744176002676623042402346036604733130522524127534777714554305412763636566643022106616734723661726160312772574551366370203115523402704104015532221722772357666
</pre>
200(base 10) is 310(base 8) so in the fist '200' characters, 666 shows up 4 times (5 if you count 6666 as twice?) [[User:Xami|Xami]] ([[User talk:Xami|talk]]) 14:01, 18 November 2013 (UTC)

: The Wolfram result is what you get when you calculate pi*3/2 in decimal, round to 14 digits after the decimal point and then convert to octal. That is, 4.7123889803846910 converted to octal. Definitely, this won't give you 200 digits precision. --[[User:Ulm|ulm]] ([[User talk:Ulm|talk]]) 15:15, 18 November 2013 (UTC)
:: It lines up too perfectly to be a coincidence. It fits all the requirements: has 666 four times within 2008 digits, and although 0000, 222, 444, and 7777 appear, they only appear once as a run. You can't double count 7777 as two 777's because it is a single run. If WolframAlpha doesn't give the correct precision, it is likely that Randall made the same error. --[[User:RainbowDash|RainbowDash]] ([[User talk:RainbowDash|talk]]) 16:59, 18 November 2013 (UTC)

Being τ, tau, is already being expressed in terms of π, pi, it shows bias. (Though I think Pau would lead to some interesting spherical geometry equations. ~~Drifter {{unsigned ip|108.162.219.214}}

The bias is worse than that: From the perspective of π, the discussion is about multiples of π, so (3/2)π (that is 3π/2 = 3τ/4) is indeed the compromise between π and 2π. But from the perspective of τ, the discussion is about fractions of τ, so the compromise between τ and τ/2 is τ/(3/2) (that is 2τ/3 = 4π/3). Maybe we can call this ‘ti’ (or ‘tie’, pace 173.245.53.184 below). —[[User:TobyBartels|TobyBartels]] ([[User talk:TobyBartels|talk]]) 20:47, 18 November 2013 (UTC)

Actually, both compromises are wrong. (3/2)π is the arithmetic mean of π and τ, while τ/(3/2) is their harmonic mean. But for geometric ratios (which these are), the appropriate mean is generally the geometric mean (hence the name). You can see how even-handed this is: it's (√2)π = τ/(√2). —[[User:TobyBartels|TobyBartels]] ([[User talk:TobyBartels|talk]]) 20:50, 18 November 2013 (UTC)

---

I am in favour of just calling it ti(e). --[[Special:Contributions/173.245.53.184|173.245.53.184]] 17:52, 18 November 2013 (UTC)

---

There are real world uses to both Tau and Pi: Pi is the number that relates to what you get when you measure a circle (the distanced around divided by the distance across); and Tau is get when you draw a circle (the distance around divided by the distance from the center). It is the difference between a mic (aka "micrometer" http://en.wikipedia.org/wiki/Micrometer ) and a protractor. Tau might have some mathematical advantages in both 2D and 3D in that it has no integer attached to it to find either circumference (2D) or surface area (3D) which makes radians and solid angles simpler. However, that advantage is lost in other dimensions and for the area of a circle.

Pau, of course, has a 61% chance of going to the dribbling spheroid hall of fame. (ref: http://www.basketball-reference.com/players/g/gasolpa01.html ), to which neither Tau nor Pi can hold a candle.~~Remo ( [[Special:Contributions/199.27.128.183|199.27.128.183]] 19:19, 18 November 2013 (UTC) )

---

The differences between Wolfram and BC really bothered me since I have used both for precision calculation in the past. The long and short of the matter, having done most of the maths 'long hand', BC is correct, Wolfram is wrong, and sadly, Randall was also wrong. It seems as tho Wolfram is rounding pi*1.5 to around 15 decimals but leaving the 9 repeating before converting to Octal.

If you take the output of octal(pi * 1.5) and paste it back into the input like so:
<pre>
4.554574376314416445676661714336617116240444076666510533533077631151350452060436452476274022621206136310000177621674175071262255702044274154476005744176002676623042402346036604733130522524127534777_8
</pre>
Wolfram gives you back (converted to decimal):
<pre>
4.71238898038468999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999
</pre>
If you give that same input to BC and ask it to convert to decimal you get:
<pre>
4.712388980384689999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999992894219160392567888
</pre>
If you do the math long hand out to 55 decimal places, pi * 1.5 equals:
<pre>
4.712388980384689857693965074919254326295754099062658731462416...
</pre>
Converting that by hand into octal is a bit of a pain, but if you do, at the 18th decimal place where BC and Wolfram differ you end up with the following:
<pre>
0.000000000000000183697019872102976583909889841150158731462416... is your remainder to be converted so far
0.000000000000000055511151231257827021181583404541015625 = 8 ^ -18
</pre>
Wolfram gives the 18th decimal as 5, BC as 3. I can't see 5 going into 18 5 times, but 3 times fits nicely.
--[[User:DarkJMKnight|DarkJMKnight]] ([[User talk:DarkJMKnight|talk]]) 20:04, 18 November 2013 (UTC)

Looks like Wolfram is simply using floating-point mathematics, presumably the IEEE "double precision". Interestingly, this is not the first time floating-point maths has been a problem; in [[287]], a similar problem caused an unintended trivial solution. [[User:Sabik|Sabik]] ([[User talk:Sabik|talk]]) 04:41, 19 November 2013 (UTC)
* On second thoughts, there's no indication that he used Wolfram Alpha; as with [[287]], it simply could have been a Perl script (or Python or pretty much any programming language). [[User:Sabik|Sabik]] ([[User talk:Sabik|talk]]) 05:25, 19 November 2013 (UTC)

---

How can 200 be octal and then mean 310 decimal???
If 200 were octal, that would be 128 decimal, so we would end up writing 128 decimals.
Of course 310 octal is 200 decimal, but taking 2008 to mean 31010 is plain crazy, even if it's the only way to make it fit the "four times 666" constraint!
What am I missing here? [[Special:Contributions/173.245.53.149|173.245.53.149]] 21:27, 18 November 2013 (UTC)

This Mathematica code searches for the pattern 666 in the octal expansion of 1.5 pi:
<pre>digits = RealDigits[3*Pi/2, 8, 10000][[1]]; Select[Range[10000 - 2], Take[digits, {#, # + 2}] == {6, 6, 6} &]
{279, 326, 495, 496, 3430, 3728, 4153, 6040, 7031, 7195, 7647, 7732, 8353, 8435, 8436, 8575, 8768, 9008}</pre>
These positions start counting with the leading "4" as position 1. It does not occur in the first 200 digits, but occurs 18 times in the first 10,000 digits. Many other digit combinations occur more times in the first 10,000 digits, including "123" (23 times), "222" (21 times), and "555" (26 times). Note that "xkcd" converted to numbers (a=1, b=2, etc.) is 24, 11, 3, 4. The combination 241134 first occurs in 1.5 pi at digit number 250,745. [[User:Dcoetzee|Dcoetzee]] ([[User talk:Dcoetzee|talk]]) 06:44, 19 November 2013 (UTC)

Wow, this filled up fast. Is it time to remove the Incomplete tag yet? [[Special:Contributions/199.27.128.66|199.27.128.66]] 03:14, 19 November 2013 (UTC)

:Please do your adds at the bottom. Otherwise it looks like as the first discussion here and everybody will ignore your comment.
:My answer is: NO. We still have to figure out if Randall is wrong or just using an algorithm nobody does understand right now.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:10, 19 November 2013 (UTC)

---

Someone said there's no indication that Randall used Wolfram, and that double-precision IEEE numbers in mostly any language would cause the same error.
This is not true: IEEE double precision numbers (binary64) are stored internally in binary.
Converting them to octal would give at most 18 nonzero significant (octal) digits, and from that point on all additional digits would be zeros (remember that an octal digit is equivalent to three bits).
What Wolfram does is rounding to a decimal number, which is not round in octal.

I think the previous is an indication that Randall did indeed use Wolfram.
Added to that, he used Wolfram in several what-if's, and in one case he used it so heavily that his IP got temporarily banned from Wolfram.
This leaves little or no doubts in me that Wolfram is the source of Randall's mistake.

Also, I still would like to know why everybody is interpreting "200 digits" as "2008 digits" and pretending that's equal to "31010 digits" instead of "12810 digits".

And out of curiosity, what happened with [[287]] and floating point numbers?
The explainxkcd for 287 says nothing about floating point.

[[Special:Contributions/173.245.53.145|173.245.53.145]] 22:09, 19 November 2013 (UTC)
* With [[287]], there was only meant to be one solution, the other solution was unintended. It's mentioned in the discussion only, not in the body of the explanation, but there's a link to an interview where he indicates that it was indeed unintentional. [[User:Sabik|Sabik]] ([[User talk:Sabik|talk]]) 07:13, 20 November 2013 (UTC)

;What is the period of the wolfram answer?
What is the repeat period of the octal answer with the 666's, (the length of the repetend) i.e. the one that comes from Wolfram, that is converting 4.71238898038469 decimal to octal? And how many 666's are in the full repetend? Oooh - I like that new word - thanks to {{w|repeating decimal}}! [[User:Nealmcb|Nealmcb]] ([[User talk:Nealmcb|talk]]) 23:22, 19 November 2013 (UTC)

:Dunno, either Randall uses WolframAlpha whithout further checks, so he has to check his sources, or we all are just dumb.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 23:54, 19 November 2013 (UTC)

: The period is 4882812500. Yes, what I mean is that it repeats every 488281250010 digits. Not sure I want to count the number of 666's in there. Oh, and thanks for the answer about [[287]], I've seen it now. -- [[Special:Contributions/173.245.53.139|173.245.53.139]] 17:46, 20 November 2013 (UTC)

I hardly dare to ask now... ;)
*What is an octal expansion?
*This explanation cannot be complete before someone explains what this actually means, to someone who have never herd of octal expansion before (like me)
[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 15:33, 21 November 2013 (UTC)
:You are absolutely right, the incomplete tag is back. It seems only math geeks were working here but it should also be explained for people with less knowledge on math.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 22:02, 21 November 2013 (UTC)

:*The wikipedia page for {{w|Octal}} contains a complete explanation. I wrote a plainer one but mine is still very long, so instead of posting it here I uploaded it [http://www.jojonete.com/00/20131121_Octal/ there]. It's very crappily formatted and not thoroughly checked as I don't have time for more at the moment, but I might improve it some other day. Please note that the only reason for not posting it here is its length, and in particular it has nothing to do with copyright issues. I mean, everybody feel free to copy, rewrite, summarize, expand, correct, destroy or do whatever to that text with no attribution, just as if it had been posted here. --[[Special:Contributions/173.245.53.145|173.245.53.145]] 22:37, 21 November 2013 (UTC)

::The explain for non math people should be much more simple. Randall likes simple English, I like simple Math. Not everything is covered but more people will understand the essentials. While I like all that details many people don't. We still do need an simple Math explain here.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 23:42, 21 November 2013 (UTC)

::I know and I agree, that's why I kept my explanation out of this discussion. My summarizing skills are just not good enough. I used the time I didn't have to reformat my explanation, but that just means it's now a bit longer than it was. I hope someone else will write a much shorter and simple one, as I just seem to be unable to do so. --[[Special:Contributions/173.245.53.145|173.245.53.145]] 01:10, 22 November 2013 (UTC)

:::Thanks for a great explanation. I knew about this system but only for integers. However, still need a word on how to get pi in Octal. Until anyone does better a link could be posted for your explanation! [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 19:54, 23 November 2013 (UTC)

::::I added the conversion part to the explanation, it's in the same link. Still way too long to post here. --[[Special:Contributions/173.245.53.117|173.245.53.117]] 03:29, 29 November 2013 (UTC)

Note that pau is Catalan for peace, which is a good solution for the pi/tau dispute. --[[Special:Contributions/173.245.53.150|173.245.53.150]] 00:10, 23 November 2013 (UTC)

:Has posted this as a trivia item. [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 20:11, 23 November 2013 (UTC)

The trivia that states that e here represents Euler's Constant, and not Euler's Number, seems to be false, is it not? e+2 being ~4.71, not ~2.58. --[[Special:Contributions/108.162.237.11|108.162.237.11]] 17:39, 24 November 2013 (UTC)
:I have removed that sentence. It was simply wrong. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 19:35, 24 November 2013 (UTC)

4/3*Pau=Tau, 2/3*Pau=Pi, therefore, It can have a practical use.--[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 10:57, 4 January 2014 (UTC)

Dear DgBrt, Please leave the explain as it is. It's "way too complex" for a reason. And the Title Text does in fact need its own header (it's not the only title text to have earned it) [[Special:Contributions/199.27.128.65|199.27.128.65]] 19:03, 19 March 2014 (UTC)
:Hello 199.27.128.65, please post new comments to the bottom. I did revert your revert because you didn't solve any of the remarks by me. And the title text EXPLAIN could be done easy: Explain that comparing e and and pi is nonsense and explain the mistake done by Randall when using Wolfram Alpha. Everything else belongs to the trivia section. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 22:36, 19 March 2014 (UTC)
::OK, we need to get the admins in here before we end up in a revert war. We already explained the intentional error from Randall, which is why it's in the explanation and not the trivia section. It CAN'T go in the trivia section because we're EXPLAINING what the error is. You don't put long explanations in the trivia section, you put them in the explanation section. THAT'S why the title text is getting its own header. [[Special:Contributions/199.27.128.65|199.27.128.65]] 02:46, 20 March 2014 (UTC)
::All right, I've submitted a request for the admins to help up. No idea when they'll get here, but it should help smooth this big mess out. [[Special:Contributions/199.27.128.65|199.27.128.65]] 02:52, 20 March 2014 (UTC)
::: [[http://www.explainxkcd.com/wiki/index.php/explain_xkcd:Community_portal/Admin_requests#Potential_Edit_War.3B_we_want_to_resolve_it_before_it_starts Here's what they've said so far]]. What do you think Dgbrt? [[Special:Contributions/199.27.128.65|199.27.128.65]] 04:27, 20 March 2014 (UTC)
::::After a week I haven't been here I still can say: calm down. My reasons are still at the incomplete tag — just read it.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 22:52, 27 March 2014 (UTC)
:::::Let's run through your arguments:
:"non Math people should also be able to understand this." I'd say the other editors did a pretty good job of that; that's the ENTIRE REASON we have an explain.
:"Randalls mistake has to be emphasised" They were. Read the explaination again.
:"everything else here is still too much, it even doesn't belong to a trivia section" But should the explanation not be as complete as possible? You underestimate just how nerdy we can get here.
:I have to side with the mods. I think this explanation was done and you're holding out for an impossible edit that will never come. [[Special:Contributions/199.27.128.65|199.27.128.65]] 02:19, 31 March 2014 (UTC)
::I will work on this, but it needs some time because I don't want to remove any of the great findings here. Non math people DON'T read all that number talks. They don't know what wolfram alpha is and that this site is sometimes WRONG. That has to be clearly explained.
::Furthermore this is NOT a nerd sniping by Randall; it's a nerd sniping ON Randall. He did use the result by wolfram alpha by error, he did figure out all that wrong "666" appearances, while he otherwise is very accurate on math.
::My idea is: Extract the essentials for the title text and add a paragraph like "Math details", "Background", or however to the bottom of the explain. In effect non math people would not read this paragraph but they can understand the essentials, other people would be happy about the deeper explain.
::I don't want to delete content, I'm just looking for a better presentation to the public. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:03, 31 March 2014 (UTC)
:::The amount of research Randal does, it's far more likely he made the mistakes on purpose in order to nerd snipe, as opposed to "he just made the mistakes on accident."
:::I agree with you on the wolfram alpha part, though, and I like your idea to summarize the errors before exploring them in full detail
:::Sorry for being so antagonizing before. [[Special:Contributions/199.27.128.65|199.27.128.65]] 04:28, 1 April 2014 (UTC)
:Just a comment here, as a non-math person, I understood all of this perfectly well. [[Special:Contributions/108.162.221.72|108.162.221.72]] 16:13, 2 May 2014 (UTC)

;Tone of "Title text" section
The [http://www.explainxkcd.com/wiki/index.php?title=1292:_Pi_vs._Tau&oldid=66351 current] tone of the title text section is inconsistent with the rest of this site. Where else does this wiki say, "Math is hard! It's not worth your time trying to understand the concepts here."?

''It consists of some of advanced trigonometry and other assorted college-level concepts that will in all likelihood just bore you if you don't care about them already.'' Really? There is not even any elementary trigonometry involved here, other than the value of PI itself. And since when is advanced trig a college level course? What is involved is the concept of bases other than base 10, specifically octal, but that is also a secondary school subject, both in mathematics and computer science.

I propose the following outline of the section:
*State that the property given in the title text does not actually hold for 1.5 * PI, but that due to an early rounding error, it might look as if it holds when shown via Wolfram Alpha. Further state that it is not clear if Randall, in relying on Wolfram Alpha, made a mistake, or if he is partaking in nerd sniping.
*Show how close Pau is to e+2.
*Explain octal -- base 8 -- first for integers, then for fractions.
*Present the actual octal expansion and show that the property does not hold.
*Explain why the Wolfram Alpha answer is different.
*Present the Wolfram Alpha answer, and show how the property [almost?] holds with that value.
*Depending on how self-referential we wish to be, explain how it might have been a plausible mistake for Randall to have relied on Wolfram Alpha, but that if it was a case of nerd sniping, then it was highly successful.
*Mention the similarity to the Feynman point.
This wiki is about explanations. We shouldn't bemoan a subject as being more difficult than it is; we should explain. -- [[Special:Contributions/108.162.219.43|108.162.219.43]] 22:52, 29 April 2014 (UTC)

:We should have two different paragraphs here:
:*The standard explain, containing the essentials like shown by 108.162.219.43 just before.
:*A "Deeper into math" one, going into more depth.
:*The "Title text" header is wrong!
:My 2 cents --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 18:58, 30 April 2014 (UTC)
::I tried to fix my old "Title Text" header, what do you think? [[Special:Contributions/199.27.130.204|199.27.130.204]] 03:29, 1 May 2014 (UTC)

:::I did my first attempt on a simple explain. Please do not revert this, but I would be happy about any enhancements. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:40, 2 May 2014 (UTC)
::::That is actually way better. Sorry for not giving you a chance before. [[Special:Contributions/199.27.130.204|199.27.130.204]] 05:07, 3 May 2014 (UTC)
:::::Thanks! --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 19:33, 3 May 2014 (UTC)

;ATM cell size?

Is it possible that this is also a reference to the compromise ATM cell size? Americans wanted 32 bytes of data per cell, to support DS0 data rates, IIRC. Europeans wanted 64 bytes to support their smallest telecom data rate (I don't remember the designation) and to reduce "cell tax" inefficiency. Neither side would capitulate, so they went with 48 bytes, which is worse than either for both sides. Diplomacy in communications standards at work! One step above "I'll take my ball and go home!" [[Special:Contributions/108.162.218.41|108.162.218.41]] 21:41, 31 May 2014 (UTC)

:That was the first thing that occurred to me! But I wonder whether Randall is that deep into such trivial communications technical details. Or should we expect him to know nearly everything about nearly everything? In any case, it's a great real-world example of an idiotic compromise, which he likes to lampoon. [[Special:Contributions/172.68.143.132|172.68.143.132]] 20:32, 31 July 2018 (UTC)

Is it worth mentioning that while Tau simplifies circumference calculations from 2*pi*r to tau*r, that it complicates area calculations from pi*r^2 to tau/2*r^2? --[[Special:Contributions/141.101.104.17|141.101.104.17]] 16:46, 11 December 2014 (UTC)

The number 666 comes from the biblical explanation of alliances that are other than godly: "the number of a man," according to Wikipedia. The scripture it comes from doesn't mention the devil. Popular culture may be making it a reality the same way made up words become socially acceptable according to dictionary writers.[[User:Weatherlawyer| I used Google News BEFORE it was clickbait]] ([[User talk:Weatherlawyer|talk]]) 14:44, 10 January 2015 (UTC)

I would argue the 666 appears twice, and 6666 appears once, and that occurence of 6666 is two more occurances of 666: digits 0 through 3 and 1 through 4. He didn't say anything about them being distinct times. [[Special:Contributions/173.245.48.91|173.245.48.91]] 21:00, 9 June 2015 (UTC)

Happy Pi Day! I know a measly 118 digits. I should try harder [[User:625571b7-aa66-4f98-ac5c-92464cfb4ed8|625571b7-aa66-4f98-ac5c-92464cfb4ed8]] ([[User talk:625571b7-aa66-4f98-ac5c-92464cfb4ed8|talk]]) 14:41, 14 March 2017 (UTC)

why not use both pi and tau? [[User:Sci0927|Sci0927]] ([[User talk:Sci0927|talk]]) 17:24, 20 December 2021 (UTC)

fun fact: https://www.piday.org/pi-facts/ links to this page on Explain XKCD <noinclude>([[1292]])</noinclude> for fact 10! [[Special:Contributions/172.69.70.210|172.69.70.210]] 18:15, 16 March 2023 (UTC)Bumpf
:Interesting. But that whole list needs rewriting so that it doesn't look like a list of different (often overlapping) facts coming from different people, without reference to each other. and the second bit to item 21 is... yeah... means nothing.
:But hello to anyone who follows the link here! [[Special:Contributions/172.70.86.127|172.70.86.127]] 20:40, 16 March 2023 (UTC)

"Pau" also happens to be made up of the first letter and the last two letters in "Portmanteau". And "Pau" could be one of the shortest portmanteau words. [[User:ColorfulGalaxy|ColorfulGalaxy]] ([[User talk:ColorfulGalaxy|talk]]) 21:27, 20 July 2023 (UTC)

I haven't been here for almost a year. Today is "e day" in the United Kingdom. Pi day is three days later. In the United States, Pi day is celebrated on March 14. [[User:ColorfulGalaxy|ColorfulGalaxy]] ([[User talk:ColorfulGalaxy|talk]]) 07:11, 19 July 2024 (UTC
:What a lot of... Today, in UK, is 19/07, nothing like 2.71828, and in three days it is 22/07 which doesn't match 3.14159 at all. 3rd of January can be 3.1, 31st of April can be 3.14, neither as 'neat' as March 14th being 3.14 (the only possibly useful and true aspect in that whole post, including the edit comment/reason for making the contribution). [[Special:Contributions/172.68.186.57|172.68.186.57]] 09:40, 19 July 2024 (UTC)
:When the Americans celebrate Pi Day on March 14 and Tau Day on June 28, the Europeans celebrate the [[Linguistics Club|biannual]] Chaos Constant Day (the chaos constant is approximately equal to 14/3 or 28/6). I don't know when they celebrate Pau Day. In China, Pi Day is [[Linguistics Club|biannual]] too, as they celebrate both the European one and the American one. [[User:ConscriptGlossary|ConscriptGlossary]] ([[User talk:ConscriptGlossary|talk]]) 11:02, 21 July 2024 (UTC)
::Yes, but you, CG, seemingly haven't dealt with the issue of the 'other' CG not making sense. (By some measures, you don't make sense yourself, but at least aren't actually provably ''wrong'' in the most basic way and are basically right about the ''first'' Feigenbaum constant. The second, being ≈2.5 could also match 5/2 (as well as 2/5 by the other method!) or 10/4 dates, in either d/m or m/d understanding. Or, for non-US, 15/6, 20/8, 25/10 and 30/12. I leave it up to the interested reader to discuss further δ or α values.)
::Anyway, enough nonsense; from me as well as you (singular/plural as you might be). [[Special:Contributions/172.70.162.186|172.70.162.186]] 12:14, 21 July 2024 (UTC)
:Pau is actually close to the Chaos Constant. But 33/7 and 4.71 don't exist on the calendar. [[User:ConscriptGlossary|ConscriptGlossary]] ([[User talk:ConscriptGlossary|talk]]) (UTC)

=== Useful ways to calculate pau ===

Pau = (-1/ζ(-1)) * (1/1/3 + 1/5/7 + 1/9/11 + 1/13/15 + 1/17/19 + 1/21/23 + 1/25/27 + ...)

(provided by [[User:ColorfulGalaxy]]) [[User:ClassicalGames|ClassicalGames]] ([[User talk:ClassicalGames|talk]]) 11:57, 3 May 2023 (UTC)

Talk:Randall Munroe

2024-09-26T23:42:34Z

141.101.99.27: Undo revision 351441 by 172.70.160.183 (talk) You do realise that the guilty changes you make to others' contributions aren't ever lost or hidden, don't you?

In comic 541 (TED Talk), Randall uses a Cueball character to refer to himself. How should this be included in the Wiki? Cited: http://xkcd.com/541/ [[User:AWiseGuy|AWiseGuy]] ([[User talk:AWiseGuy|talk]]) 21:50, 1 September 2012 (UTC)

:Hrm... I would suppose it would be something along the lines of this "In comic 541, Randall uses Cueball to refer to himeself." (with all of the links and stuff). Which is pretty exactly much what you wrote. That's how I think it should be done. But where to place it? Seeing as we have very little content as is, just put it at the bottom in the "main" part, and over time it'll fall into place as more content is added, probably. That's my two [insert monetary value here]s. {{User:Grep/signature|04:10, 25 February 2014}}

Randall needs a proper introduction here. This article should be much more serious — based on the English Wiki.--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:25, 25 February 2014 (UTC)

I think Randall would find no higher compliment than to have a wiki article about him full of "citation needed" tags :D --[[User:Alcatraz ii|Alcatraz ii]] ([[User talk:Alcatraz ii|talk]]) 02:05, 11 October 2014 (UTC)
== Complete? ==

I'm not suggesting we're at that point right now, but what is the goal for this article to be deemed "complete?" as a bio of living person is rarely going to ever be "complete".

This is the xkcd wiki, so I would argue that if there was going to be a thorough and complete Randall article anywhere, it would be here... so at very least it probably ought to be more thorough than his general wikipedia page... [[User:TheHYPO|TheHYPO]] ([[User talk:TheHYPO|talk]]) 15:24, 7 July 2014 (UTC)

== Picture? ==

Just wondering where Randall's picture went... --[[Special:Contributions/173.245.54.63|173.245.54.63]] 15:33, 23 December 2015 (UTC)

== Quaker reference? ==

There is no reference for Munroe being a Quaker except a footnote in a joke comic. Additionally, engineering is an, um, /unusual/ career for a parent who is a Quaker. This is likely an attempt from Munroe to generate a case of citogenesis (https://en.wikipedia.org/wiki/Wikipedia:List_of_citogenesis_incidents, https://en.wikipedia.org/wiki/Circular_reporting, https://xkcd.com/978/) as a small-scale Wikipedia prank. [[User:Djbrasier|Djbrasier]] ([[User talk:Djbrasier|talk]]) 17:05, 9 May 2018 (UTC)
: It's true, and [https://slate.com/culture/2019/09/xkcd-randall-munroe-interview-how-to-book-wikipedia.html you got quoted in ''Slate!''] [[Special:Contributions/172.70.210.145|172.70.210.145]] 16:04, 24 July 2022 (UTC)

== Our Savior ==

At some point, someone changed the caption for the picture to say "Our Savior". Whoever you are, congratulations. You got a chuckle out of me. [[Special:Contributions/172.69.90.67|172.69.90.67]] 15:56, 22 November 2021 (UTC)

== Wondering if we should add What if? 2 as upcoming ==

The title says it all.--[[Special:Contributions/108.162.216.141|108.162.216.141]] 10:35, 7 September 2022 (UTC)
: Absolutely! How about in place of that nag trying to get us to expand [[1608: Hoverboard]]? [[Special:Contributions/172.69.34.94|172.69.34.94]] 03:58, 9 September 2022 (UTC)

== A couple of UK radio 'appearances'... ==

Might be worth a listing, on the proper page, but I leave it to someone else to work out how. Randall has featured in two (at least) BBC Radio 4 programmes ("programs", if you wish), in the last few days:
* The Infinite Monkey Cage, a general science-explainer-with-comedy show, this episode being around the theme of how to use mathematics in interesting ways. A somewhat anarchic (loosely planned) stream of thoughts in the presence of an audience.
* The Museum Of Curiosity, a comedy-interview/conversation show with a science bent. This is a more introverted casual conversation (no audience, but cross-talk) following its general template of first asking each guest a little about themselves and then asking them each to present 'something' as a talking point.
In both formats, Randall is one of a small panel of guests (and a pair of hosts, interestingly), and only directly contributes to about a third of each half-hour episode, but ends up talking about some of his work (especially about a lot of soup) in both. He's not the most talkative, in either case, but he holds his own and imparts his own wisdom sufficiently well. I haven't thoroughly searched yet to see if there were/will be more broadcasts with him in other BBC radio (or TV?) shows, while he was obviously at the forefront of the guest-bookers' thoughts; the [https://www.bbc.co.uk/search?q=Randall+Monroe obvious search] seems to be too title-orientated to extract "...with guest" mentions.

At least for the time being (and perhaps subject to some geographic browsing restrictions) the two episode links that might be useful (at least as a jumping-off point) are [https://www.bbc.co.uk/programmes/p0f1wc06 here] and [https://www.bbc.co.uk/programmes/m001jsdr here]. The former is also a published podcast, so should be freely found in that sphere of downloadables. And then there's the whole BBC Sounds platform, if you can and do access that. And the usual schedual of repeat broadcasts will happen, within the week. TIMC on Thursday (9/Mar/2023) 16:00GMT on R4, TMOC on Sunday (12/Mar) shortly after noon, ditto. (Further future readers might be lucky with somewhere like R4Extra having either series, if not precise episode, finding an archive slot at some handy but so far indeterminate point in their own near-futures.)

...anyway, FYI, for anyone who finds this useful news, or a point of historic record. [[Special:Contributions/172.71.178.64|172.71.178.64]]

It seemed that Randall had discovered Explain XKCD. [[User:ClassicalGames|ClassicalGames]] ([[User talk:ClassicalGames|talk]]) 09:36, 30 July 2023 (UTC)

:If it's true, then this may put the wiki in danger. [[User:ConscriptGlossary|ConscriptGlossary]] ([[User talk:ConscriptGlossary|talk]]) 08:31, 26 September 2024 (UTC)

::Probably not. And stop talking to yourself. [[Special:Contributions/172.70.91.94|172.70.91.94]] 13:41, 26 September 2024 (UTC)

== What If adaptation ==

What If books now have an official ongoing adaptation on Youtube, should it be added? Channel info says it's Neptune studios making it, not Randall personally, but without his approval it wouldn't have happened and it's still ''his''

https://youtube.com/channel/UC6IxnFzHofFJ5X2PycSMsww

[[Special:Contributions/162.158.102.213|162.158.102.213]] 09:05, 27 February 2024 (UTC)

== I understand why he doesn't edit here, but is he a reader? ==

Has he ever said anything about whether or how often he looks at explanations here? [[Special:Contributions/162.158.186.179|162.158.186.179]] 07:48, 26 September 2024 (UTC)
:If he had implied it, someone would surely mention it. But, if I were him, I wouldn't just from principle.
:More certainly, though, he's changed some comics based upon Xwitter feedback about (apparent) errors, yet there are certainly equal errors noted here that he hasn't done anything about, which suggests no. (Or else they fall beneath his threshold to bother with.) [[Special:Contributions/172.70.91.94|172.70.91.94]] 13:41, 26 September 2024 (UTC)

2487: Danger Mnemonic

2024-03-19T22:41:40Z

141.101.99.27: /* Explanation */ "thats a of friend of Jack" is ungrammatical. Assuming this change intended (though "that's a" seems unnecessarily clunky for a saying...)

{{comic
| number = 2487
| date = July 9, 2021
| title = Danger Mnemonic
| image = danger_mnemonic.png
| titletext = It's definitely not the time to try drinking beer before liquor.
}}

==Explanation==
The teacher [[Miss Lenhart]] warns two small kids using a danger {{w|mnemonic}}.

However, this is actually a mash-up of three different common danger mnemonics, each of which warn about different hazards.

*Red touches black, that's a friend of Jack; red touches yellow, you're a dead fellow.

This mnemonic is intended to help recognize venomous {{w|coral snake}}s, which have brightly colored stripes. Some nonvenomous {{w|king snake}} species have similar striped colors, but in different patterns. '''NOTE THAT THIS MNEMONIC IS NOT ACCURATE, ESPECIALLY OUTSIDE THE EASTERN UNITED STATES WHERE IT WAS ORIGINALLY CREATED'''; many species of coral snake have black stripes touching red stripes, and if the snake has atypical coloration, then the rhyme may still lead to misidentification even in the right region. The safest course of action is to avoid any snake with the warning colors of red, yellow/white, and black stripes. Another corruption of the same warning features in [[1604: Snakes]].

*Leaves of three, leave them be; berries white, poisonous sight. (Alternatively, "berries white, run in fright" or "hide from sight.")

This mnemonic is used to identify {{w|poison ivy}} and {{w|poison oak}} throughout much of North America. These plants both produce an oily surface resin called urushiol, which causes an allergic reaction in the majority of people. Touching either plant can result in contact dermatitis, which can be severely itchy or painful. If burned, the urushiol can be inhaled, causing lung irritation. While rarely serious, these reactions are often severely unpleasant and can last for weeks, so avoiding the plants is well advised. Both plants generally grow three leaves at the end of each branch, and grow berries that turn white when ripe. The mnemonic helps in remembering this characteristic to distinguish them from similar-looking but harmless vines. See [[443: Know Your Vines]].

*Red sky at night, sailor's delight; red sky in the morning, sailors take warning.

This {{w|Red sky at morning|mnemonic}} predicts bad/good weather conditions based on a particularly red sunrise/sunset. It is predictive at {{w|middle latitudes}} where the prevailing winds go from west to east. Regions of higher air pressure will cause a particularly red sky at sunrise/sunset, so a red sky in the evening indicates a high pressure system is coming in from the west with its calmer weather, while a red sky in the morning indicates a low pressure front coming in (usually with rain and rougher weather). In some countries (such as the United Kingdom), the saying mentions shepherds rather than sailors. Randall actually wrote a [https://www.nytimes.com/2019/08/13/science/what-makes-a-red-sky-at-night-and-at-morning.html newspaper article] explaining this phenomenon.

Combining all three sayings sounds particularly ominous. It implies that a person is involved with a situation simultaneously involving coral snakes, poison ivy, and potentially nasty weather. In such a case, Miss Lenhart advises the children to "just get out of there", implying that the situation is too dangerous to try to deal with.

The title text refers to another mnemonic: 'Beer before liquor, never been sicker; liquor before beer, you're in the clear.' Unlike the first three mnemonics, which are genuinely useful for avoiding danger, this one is [https://www.nytimes.com/2006/02/07/health/the-claim-mixing-types-of-alcohol-makes-you-sick.html largely a myth], as the order in which you drink alcohol is unlikely to impact how sick you become. However, whether the mnemonic is true or not, testing it would involve multiple drinks of alcohol, which would be ill-advised when facing a dangerous situation, particularly one as bizarre and complex as implied in this strip.

See also [[2422: Vaccine Ordering]] for the previous time ''xkcd'' referenced the latter mnemonic.

See also [[2038: Hazard Symbol]] for another combination of danger warnings.

==Transcript==
:[Miss Lenhart is holding a finger up in front of two children: a boy with spiky hair and Jill.]

: Miss Lenhart: Now, remember:
: Miss Lenhart: If red touches yellow amid leaves of three under a red sky at morning,
: Miss Lenhart: You should probably just get out of there.

{{comic discussion}}

[[Category:Comics featuring Miss Lenhart]]
[[Category:Comics featuring Jill]]
[[Category:Food]]
[[Category:Animals]]
[[Category:Weather]]
[[Category:Kids]]

2738: Omniknot

2023-02-16T12:36:32Z

141.101.99.27: /* Explanation */ In leiu of giving [Citation needed] on "knot means knot", refining and repositioning this bit to just explain the "omni-" where it might be useful. And proper wikilink. And incompetent amateurs are probably reef/granny agnostic...

{{comic
| number = 2738
| date = February 15, 2023
| title = Omniknot
| image = omniknot_2x.png
| imagesize = 358x288px
| noexpand = true
| titletext = The Gordian knot is an omniknot tied using every bend in the Ashley Book of Knots, and then for extra security the upper rope at every crossing is connected to the lower with a randomly-chosen hitch.
}}

==Explanation==
{{incomplete|Created by THE KNOTTED OMNIBOT - Please change this comment when editing this page. Do KNOT delete this tag too soon.}}

The comic jokes that if you have several potential {{w|knot}}s which could be tied in a given situation, rather than being forced to choose one, you can simply use all of them and create the comic's "Omniknot." The prefix omni- means "all", and so the "all-knot" is the knot containing all the other knots (...that one knows).

Knots in the middle, from top to bottom:
* {{w|Granny knot}}: A bad knot, usually the result of an improperly tied reef knot.
* {{w|Reef knot}}: Also known as the square knot, one of the most commonly tied by competent amateurs. But a poor and possibly dangerous choice as a load-bearing bend, as it has a tendency to {{w|Knot#Capsizing|'capsize'}} and untie itself.
* {{w|Sheet bend}}: Similar to the bowline, a popular, all around good choice, especially if one rope is thinner than the other (the loop should be on the thinner rope).
* {{w|Double sheet bend}}: A more secure version of the previous knot, especially if one rope is much thinner than the other.
* {{w|Carrick bend}}: A very good bend, especially if both ropes are similar in kind and thickness. This version, however, with the ends emerging from the same side is weaker than if the ends were diagonal from each other.

On the sides are {{w|bowline}}s and each rope is terminated by a {{w|figure-eight knot}}. (A "bend" is a knot that connects two ropes or lines. A "hitch" is a knot that connects a rope (a.k.a. line) to something like a post, loop, or shackle.)

In the title text, the {{w|Gordian Knot}} is a knot which purportedly was extraordinarily complex and nearly impossible to untie. According to legend, when Alexander the Great was faced with the knot, he simply drew his sword and cut it in half, thereby "untying" it and solving the unsolvable. The Gordian Knot is now used as a linguistic metaphor to describe a problem whose solution, rather than being to directly solve it head-on, involves working around or otherwise bypassing its apparent constraints.

{{w|The Ashley Book of Knots}} is an encyclopedia describing thousands of different knots. Though it is now dated because it was written before the widespread adoption of synthetic fiber rope, it is still considered the reference in knot tying. Using all bends from the book and as many hitches would make the final result very complex indeed. Randall proposes here that this was the true origin of the mythical Gordian Knot.

In practice, it is not recommended to use overly complex knots as they provide little in term of additional security compared to a well chosen, simpler knot. The ease of tying and untying, especially in less than ideal conditions is also an important factor to consider. If strength is more important than the ease of tying and untying, {{w|Rope splicing|splices}} should be considered instead of knots as they don't weaken the rope as much as knots.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[There are two ropes tied together with several different kinds of knots.]

:[Caption below the panel:]
:If you know several knots and can't figure out which one to use, just tie one of each.

{{comic discussion}}

2405: Flash Gatsby

2020-12-31T10:44:08Z

141.101.99.27: /* Explanation */ A variety of interesting etymologies, of widely varying likelihood of being Randall's intent. All except the first converge in the likes of https://en.wikipedia.org/wiki/Flash_Harry_(St_Trinian%27s), but I don't think that inspired this.

{{comic
| number = 2405
| date = December 31, 2020
| title = Flash Gatsby
| image = flash_gatsby.png
| titletext = Protip: At midnight your excuse for not having read The Great Gatsby can switch from "I'm worried about violating copyright" to "I think my copy requires Flash."
}}

==Explanation==
{{incomplete|Created by a green light. Please mention here why this explanation isn't complete. It's hard to enumerate why the moments that the copyright expires and flash is no longer officially supported, are not exactly the same, but randall seems to expect us to do this. Do NOT delete this tag too soon.}}

This comic unfolds over the last few seconds of 2020 and the first few seconds of 2021. [[Cueball]] is attempting to do something requiring the overlap of two eras that only abut.

''{{w|The Great Gatsby}}'' is a classic novel written by {{w|F. Scott Fitzgerald}} in 1925. Copyright law in the United States of America, where ''The Great Gatsby'' was first published, was retroactively extended several times in the 1990s and early 2000s, causing the copyright on ''The Great Gatsby'' to extend [https://www.mentalfloss.com/article/595567/why-the-great-gatsby-isnt-public-domain until the end of 2020]. In 2021, it will finally enter the public domain so that it will become legal to make a copy without violating copyright law.

{{w|Adobe Flash}}, formerly known as Shockwave Flash, is a web plugin that was commonly used by many websites in the late 1990s and 2000s. However, it was repeatedly exploited by hackers, incurring heavy costs on {{w|Adobe Inc.|Adobe}} as they tried to update Flash against these attacks after rushing features out before stabilising them. Newer technologies are now able to provide comparable features with more compatibility, more community involvement, and less risk, so support for Flash is being phased out by most web browsers. Adobe is officially discontinuing Flash at the end of 2020. Therefore, a Flash version of ''The Great Gatsby'' will become legal at the very moment that everyone should stop using it.

In line with Adobe's decision, [https://www.chromium.org/flash-roadmap#TOC-Upcoming-Changes Chrome is blocking Flash in January]. This will make [https://www.newgrounds.com/games entire internet culture histories spanning many years of making and engaging Flash experiences] unusable for most people.

In this comic, [[Cueball]] suggests that the withdrawal of Flash supports occurs a second or two after the copyright expiration rather than simultaneously with it, presumably implying that the withdrawal of Flash support takes human intervention rather than occuring automatically (e.g. via an at or cron job), whereas copyright expiration requires no action, it simply happens at a given point in time.

The title wording does multiple work with a number of possible meanings to it. It's the 'Gatsby' book via the medium of the electronic Flash format. Because of the briefest of availability (at best, a single moment), it appears and disappears again 'in a flash'. Being 'flash' is a very apt description of the millionaire Gatsby character himself (just as 'flash the cash' is being ostentatious). And, if the endeavour is not actually as legitimate as hoped, the word has also refered to felonious behaviours and forged copies.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:Off panel voice: 3... 2... 1... Happy New Year!
:Cueball: Ok, It’s up!
:Cueball: Annnnnd... support was pulled, it’s down again.

:[Caption below the panel]
:

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Fiction]]
[[Category:Internet]]
[[Category:Protip]] <!-- title text ->

Talk:149: Sandwich

2014-02-20T22:25:35Z

141.101.99.27:

Note that it is more effective to write "sudo !!" to redo the last command but with sudo added to it. {{unsigned|Agge.se}}

:Using <code>sudo !!</code> outputs the previous command with sudo into your bash (other shells as well) history, so to bash what you said was "sudo make me a sandwich" not "sudo !!". [[User:Lcarsos|lcarsos]] ([[User talk:Lcarsos|talk]]) 16:46, 29 October 2012 (UTC)

<code>sudo</code> requires '''user''' password, not admin password, but you need to be in <code>sudoers</code> file. --[[User:JakubNarebski|JakubNarebski]] ([[User talk:JakubNarebski|talk]]) 12:14, 15 December 2012 (UTC)

:How many people will know the difference? In a typical Ubuntu-family install with only one human user, root doesn't ''have'' a password, but the one user who does is a sudoer (and has to use <code>sudo</code> or <code>su</code> to act as root, rather than doing so starting at login). [[User:Promethean|Promethean]] ([[User talk:Promethean|talk]]) 06:08, 30 August 2013 (UTC)

I believe the original comic actually read "Sudo bang bang" instead of "Sudo make me a sandwich". Here's a link to what I think is a copy of the [http://stackoverflow.com/questions/15137461/what-is-sudo-bang-bang original]. I'm not sure which of the two is actually the original. {{unsigned ip|‎99.95.158.248}}
:The words "bang bang" (particularly the first B) look a bit fuzzy/pixelated compared to the rest of the text, which gives me the feeling that it was edited from this one, which is the original. [[User:Zowayix|Zowayix]] ([[User talk:Zowayix|talk]]) 23:03, 23 January 2014 (UTC)

Comment: This conversation is an easter egg in Google Now on Android tablet. Using voice search to say "make me a sandwich" will give the reply "what? make it yourself", adding "sudo" will get the response "ok". I assume the Google now implementation came later and is based on xkcd.