explain xkcd - User contributions [en]

1445: Efficiency

2014-11-10T06:28:48Z

ParadoX: /* Explanation */ There are plenty of studies that suggest little improvement over QWERTY, but I don't support either configuration, just being technically correct.

{{comic
| number = 1445
| date = November 10, 2014
| title = Efficiency
| image = efficiency.png
| titletext = I need an extension for my research project because I spent all month trying to figure out whether learning Dvorak would help me type it faster.
}}

==Explanation==
{{incomplete|First draft.}}
This comic refers to the fact that there are often multiple ways in which to deal with a problem or task, with one of the methods being more efficient, though sometimes only slightly. Many people try to avoid unnecessary work by finding the easier of the methods, but this can prove to be more difficult than even just choosing the harder task, even to the point of requiring more time than the original tasks as illustrated in the comic. Randall cites this as the reason for his inefficiency.

The title text refers to the {{w|Dvorak_Simplified_Keyboard|Dvorak}} keyboard layout, an alternative to the almost universally accepted {{w|QWERTY}} layout, which is known to supposedly improve typing efficiency.

A similar comic that addressed wasted time due to bad time management was [[1319: Automation]].

==Transcript==
:[A graph titled Time Cost]
:Strategy A
:[Short line beside A]
:Strategy B
:[Slightly longer line beside B]
:Analyzing whether strategy A or B is more efficient
:[A much longer line next to this, about 10 times the length of B]
:The reason I am so inefficient
{{comic discussion}}

Talk:825: Guest Week: Jeffrey Rowland (Overcompensating)

2014-04-04T01:00:04Z

ParadoX:

The Turkey Voluntary Extinction Movement has to be a riff on the Voluntary Human Extinction Movement (www.vhemt.com [I'm not sure what the "t" is doing there] ). Alas, their primary purpose seems to be selling TShirts (their site concludes with the FAQ Question: How do I order stickers, T-shirts, and stuff?)[[User:Traveller|Traveller]] ([[User talk:Traveller|talk]]) 23:06, 23 October 2013 (UTC)
The Globe shrinks noticeably between the first and last panels. --[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 01:00, 4 April 2014 (UTC)

Talk:837: Coupon Code

2014-04-04T00:59:00Z

ParadoX: /* Price of the product */

If you see in the first frame, the Subtotal is a one-digit number, possibly $3.19. Yet the tax is way higher, and the subtotal is higher still. Thoughts?
--Kuilin Li, kuilin@gmail.com, didn't bother registering.
[[Special:Contributions/67.175.58.94|67.175.58.94]] 03:00, 9 January 2013 (UTC)

: The word next to the (potential) 3.19 isn't 'subtotal', though. The first letter might be a K or R, no idea on the second, the third is probably an E, K or R again, a 'one foot' letter like I or T, a C (I think), another 'one foot', a round bottom like a C or O, then possibly an H. I'm sure it's a real word, knowing how much detail he puts in the simplest things, am pretty sure it's not 'subtotal', but no idea otherwise what it actually is. --[[User:StarChaser Tyger|StarChaser Tyger]] ([[User talk:StarChaser Tyger|talk]]) 03:59, 30 January 2013 (UTC)

:: My guess is that it says "AMERICIUM". —Tanner Swett [[Special:Contributions/107.5.152.253|107.5.152.253]] 22:29, 22 March 2013 (UTC)

::: Hmm, looks like you could be right. Also, {{w|americium}} is a radioactive element commonly used (in tiny amounts) in {{w|smoke detector}}s. It's probably the only {{w|transuranic element}} you can find in your house. --[[User:Aaron of Mpls|Aaron of Mpls]] ([[User talk:Aaron of Mpls|talk]]) 03:46, 29 August 2013 (UTC)

I don't really get the joke: is it about the idea that stealing something from the house of a dying woman is a rather common thing to have on one's conscience? and Cueball tries to leverage on that everywhere he can? Or would it be that Cueball really ''knows'' who is on the other side and what he can pressure them on? - [[User:Cos|Cos]] ([[User talk:Cos|talk]]) 14:28, 7 February 2013 (UTC)
:The joke is that coupon codes are normally bland, corporate, impersonal, and small (you don't save that much money generally). Also, they're now sometimes shared on sites like RetailMeNot. This is just the opposite. It's a highly profitable way of exploiting a personal secret the buyer knows about the seller. [[User:Mattflaschen|Mattflaschen]] ([[User talk:Mattflaschen|talk]]) 03:48, 9 February 2013 (UTC)
:: Highly effective way? Only if the buyer was reading the discount code input manually! [[Special:Contributions/220.224.246.97|220.224.246.97]] 12:53, 21 February 2013 (UTC)
:::It's the romantic image that there is more behind the interface than mere, cold technology. But atleast a sentinent being, if not humans. I don't think there's an actual joke that is supposed to make you laugh here though. --[[Special:Contributions/91.46.105.142|91.46.105.142]] 22:11, 3 July 2013 (UTC)

It is way to specific to be a "shot in the dark", the extortionist clearly has inside knowledge. [[Special:Contributions/108.162.246.117|108.162.246.117]] 01:01, 18 January 2014 (UTC)

== Price of the product ==

I think the price is 3.14, as it is the closest number that matches with the image & perfectly divides into 65.94 (80.02-14.08). --[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 00:58, 4 April 2014 (UTC)

Talk:837: Coupon Code

2014-04-04T00:58:19Z

ParadoX: /* Price of the product */

If you see in the first frame, the Subtotal is a one-digit number, possibly $3.19. Yet the tax is way higher, and the subtotal is higher still. Thoughts?
--Kuilin Li, kuilin@gmail.com, didn't bother registering.
[[Special:Contributions/67.175.58.94|67.175.58.94]] 03:00, 9 January 2013 (UTC)

: The word next to the (potential) 3.19 isn't 'subtotal', though. The first letter might be a K or R, no idea on the second, the third is probably an E, K or R again, a 'one foot' letter like I or T, a C (I think), another 'one foot', a round bottom like a C or O, then possibly an H. I'm sure it's a real word, knowing how much detail he puts in the simplest things, am pretty sure it's not 'subtotal', but no idea otherwise what it actually is. --[[User:StarChaser Tyger|StarChaser Tyger]] ([[User talk:StarChaser Tyger|talk]]) 03:59, 30 January 2013 (UTC)

:: My guess is that it says "AMERICIUM". —Tanner Swett [[Special:Contributions/107.5.152.253|107.5.152.253]] 22:29, 22 March 2013 (UTC)

::: Hmm, looks like you could be right. Also, {{w|americium}} is a radioactive element commonly used (in tiny amounts) in {{w|smoke detector}}s. It's probably the only {{w|transuranic element}} you can find in your house. --[[User:Aaron of Mpls|Aaron of Mpls]] ([[User talk:Aaron of Mpls|talk]]) 03:46, 29 August 2013 (UTC)

I don't really get the joke: is it about the idea that stealing something from the house of a dying woman is a rather common thing to have on one's conscience? and Cueball tries to leverage on that everywhere he can? Or would it be that Cueball really ''knows'' who is on the other side and what he can pressure them on? - [[User:Cos|Cos]] ([[User talk:Cos|talk]]) 14:28, 7 February 2013 (UTC)
:The joke is that coupon codes are normally bland, corporate, impersonal, and small (you don't save that much money generally). Also, they're now sometimes shared on sites like RetailMeNot. This is just the opposite. It's a highly profitable way of exploiting a personal secret the buyer knows about the seller. [[User:Mattflaschen|Mattflaschen]] ([[User talk:Mattflaschen|talk]]) 03:48, 9 February 2013 (UTC)
:: Highly effective way? Only if the buyer was reading the discount code input manually! [[Special:Contributions/220.224.246.97|220.224.246.97]] 12:53, 21 February 2013 (UTC)
:::It's the romantic image that there is more behind the interface than mere, cold technology. But atleast a sentinent being, if not humans. I don't think there's an actual joke that is supposed to make you laugh here though. --[[Special:Contributions/91.46.105.142|91.46.105.142]] 22:11, 3 July 2013 (UTC)

It is way to specific to be a "shot in the dark", the extortionist clearly has inside knowledge. [[Special:Contributions/108.162.246.117|108.162.246.117]] 01:01, 18 January 2014 (UTC)

== Price of the product ==

I think the price is 3.14, as it is the closest number that matches with the image perfectly divides into 65.94 (80.02-14.08). --[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 00:58, 4 April 2014 (UTC)

Talk:837: Coupon Code

2014-04-04T00:57:35Z

ParadoX: /* Price of the product */ new section

Talk:1292: Pi vs. Tau

2014-01-04T10:57:11Z

ParadoX: Yes!

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)

----

(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)

Talk:903: Extended Mind

2013-12-13T09:03:55Z

ParadoX: No-one ever knew about this?

Title text is true - unless you happen to stumble upon any one of: {{w|Fact}}, {{w|Proof (truth)}}, {{w|Evidence}}, or {{w|Truth}}. Then you'll be stranded in an eternal loop.
:What do you mean? {{w|Fact}} works fine, you get there in 7 steps. Proof gets you there in 6 - you go to {{w|Necessity and Sufficiency}} not {{w|Evidence}}. Same for {{w|Evidence}}. {{w|Truth}} leads you to {{w|Fact}}. So all of your examples actually work.
--[[User:T0IVI|T0IVI]] ([[User talk:T0IVI|talk]]) 09:27, 28 December 2012 (UTC)

Yeah, I hit a loop on the page Community. Went right from National community to Community again. {{unsigned|69.91.105.111}}

These infinite loops seem to be 'fixed', I went through fact and other stuff right to philosophy.{{unsigned|141.35.48.11}}

Another loop is "England". It goes right to "Countries of the United Kingdom" which returns immediately to England.

Finally we all end up in {{w|Reality}}. [[Special:Contributions/85.178.28.173|85.178.28.173]] 21:16, 29 May 2013 (UTC)

I do have to say that the best loop that doesn't feed to Philosophy is {{w|Sand Fence}} and {{w|Snow Fence}}. The first sentence of each article is identical except for switching the instances of sand and snow. --[[Special:Contributions/68.97.21.122|68.97.21.122]] 05:17, 6 July 2013 (UTC)

Randall is either mistaken or intentionally misinformative (or rather, politically correct) in his IQ estimates. What's a car hyperbole aside, the cluelessness, sentence length, and spelling of the outage-messages remind of a person in their low 90s-high 80s, if not lower, and Randall is clearly more than 120, (conservative) average for physics majors as it might be. [[Special:Contributions/178.42.101.38|178.42.101.38]] 20:08, 13 July 2013 (UTC)

==What can we learn?==
I've learned that memorizing facts is so yesteryear. Over next few years facts will be even easier to find, understand, use, reference and forget. When in school we should concentrate not on memorizing facts we can look up later, but rather new methods to think outside the box full of facts others placed inside it. (Thank you Mr. XKCD) - [[User:E-inspired|E-inspired]] ([[User talk:E-inspired|talk]]) 13:42, 28 February 2013 (UTC)
: That is true, but the overhead for looking something up versus remembering it is usually great enough that memorizing some things (multiplication tables come to mind) can increase the speed we can arrive at conclusions, or can give us other options (correlation between spark plug gapping and engine performance) that might not have come to mind otherwise. Outside of that, even though we forget much of it, having a vague sense of things (dates, locations/countries, etc) allow us to start out knowing at least something (order of things that occurred, Egypt being in Africa, Pythagorean theorem). This is just my opinion, and I may be biased, since I like facts. [[User:Tryc|Tryc]] ([[User talk:Tryc|talk]]) 13:19, 25 July 2013 (UTC)

You can't teach everyone to think outside the box, that would spoil my advantage over the common man. [[Special:Contributions/184.66.160.91|184.66.160.91]] 03:03, 26 August 2013 (UTC)

Wikiloop: (noun) A loop that results in wikipedia articles from clicking the first link not in brackets or italics over and over again.
Here is the most commonly encountered wikiloop. (Reality is also the first link in Philosophy) --[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 09:03, 13 December 2013 (UTC)
Reality
Existence
World
Human
Primate
Mammal
Clade
Tree of life (biology)
Metaphor
Figure of speech
Word
Linguistics
Science
Knowledge
Fact
Reality
...

Talk:675: Revolutionary

2013-12-10T09:24:06Z

ParadoX: No-one ever though of this comment? NO-ONE?!?!?!

Looks like this guy doesn't know about Lorentz contraction and time dilation. That or he's so confident about his idea that he hasn't bothered to look further into the subject. --[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 09:24, 10 December 2013 (UTC)

explain xkcd:Community portal/Miscellaneous

2013-09-27T05:16:33Z

ParadoX: /* Adblock */

<noinclude>{{Community portal}}</noinclude>

== The Community Portal's design ==

{{tl|Community portal}} looks too Wikipedia-ish (because that's where I got it). Someone who can design things should probably fix that. It isn't protected for the time being, though it probably will be in the future (high-visibility template). --''[[User:Philosopher|Philosopher]]'' [[User talk:Philosopher|Let us reason together.]] 00:54, 4 August 2012 (EDT)

== Common mistake ==

This affects all pages that ever say "alt text" in reference to the TITLE text on xkcd images. "Alt text" is incorrect; Alt text refers to the text that is shown as an alternative when images are not displayed. Title text is what xkcd uses and is shown as a tool tip-like bubble when images are hovered over.

I would correct this myself but I saw no way to edit the main page. --[[User:Jillysky|Jillysky]] ([[User talk:Jillysky|talk]]) 14:21, 6 August 2012‎ (UTC)

:You actually don't need to edit the main page to fix it, as what's there is just a mirror (transclusion) of the actual content from the comic page, at [[Curiosity]], which is open for editing by anyone. Then again, the "alt-text" in that case is generated by a template, {{tl|comic}}, so that's where we should fix this. The template's code, however, is currently a terrible mess (sorry!), so I went ahead and took care of it. Thanks for catching that! --[[User:Waldir|Waldir]] ([[User talk:Waldir|talk]]) 16:24, 6 August 2012 (UTC)

:Ah? So it's wrong, for instance, on http://m.xkcd.com? because of that I took it for granted that we could call it the alt-text... - [[User:Cos|Cos]] ([[User talk:Cos|talk]]) 17:38, 6 August 2012 (UTC)

:: Yes. If you look at the page's html source, you'll see:
<nowiki><img
id="comic"
src="http://imgs.xkcd.com/comics/curiosity.png"
title="As of this writing the NASA/JPL websites are still overloaded. Trying CURIOSITY-REAR-CAM_[256px_x_256px].torrent.SwEsUb.DVDRip.XviD-aXXo.jpg instead."
alt="Curiosity"></nowiki>
::(line breaks added for clarity) --[[User:Waldir|Waldir]] ([[User talk:Waldir|talk]]) 23:54, 6 August 2012 (UTC)

:::That was my error in the template. I knew "image text" that has been commonly used by Jeff was not techically correct, but I didn't actually go back and confirm it was alt text before I included that tag in the template. That's to Waldir (I believe?) for correcting the template. [[User:TheHYPO|TheHYPO]] ([[User talk:TheHYPO|talk]]) 14:14, 7 August 2012 (UTC)

== When the "official" transcript is wrong? ==
I did [[903: Extended Mind]]. Interestingly, the transcript on xkcd.com is missing the bottom line "When Wikipedia has a server outage, my apparent IQ drops by 30 points." I assume we want a complete transcript, rather than whatever xkcd.com says it is...? [[User:Stevage|Stevage]] ([[User talk:Stevage|talk]]) 04:10, 17 November 2012 (UTC)

:We're focusing on the actual transcript of the comic, not the xkcd.com transcript. The official transcript is usually right, but even Randall makes mistakes sometimes. [[User:Davidy22|Davidy22]][[User talk:Davidy22|<tt>(talk)</tt>]] 04:24, 17 November 2012 (UTC)

== Milestone: half the comics explained!! ==

Hi all! I'm pleased to announce that we have just broke the 50% mark for xkcd explanations! The page that balanced the count (568 explained, 568 to go, at the time) was [[877: Beauty]], created 01:31 UTC, 21 November 2012 by [[User:Davidy22]]. Congratulations!! :D --[[User:Waldir|Waldir]] ([[User talk:Waldir|talk]]) 03:10, 21 November 2012 (UTC)

:The caterer's been called! The punch will be arriving soon! Go [[User:Davidy22|Davidy22]]! [[User:Lcarsos|lcarsos]]_a ([[User talk:Lcarsos|talk]]) 06:53, 21 November 2012 (UTC)

::[[File:freedom.png]] Punch is served! [[User:Davidy22|Davidy22]][[User talk:Davidy22|<tt>(talk)</tt>]] 07:11, 21 November 2012 (UTC)

But the Main page says 407 explanations, 731 to go! What's up with that? --[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 21:00, 23 November 2012 (UTC)

== Reverse? ==

Why in the Archive why are all the thing up until "Heatmap" in Reverse? Can someone please answer? [[User:Tmack3|Tmack3]] ([[User talk:Tmack3|talk]]) 08:28, 20 February 2013 (UTC)
:Archive? Can you provide a link or screenshot? '''[[User:Davidy22|Davidy22]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 04:43, 19 February 2013 (UTC)

http://xkcd.com/archive/ [[User:Tmack3|Tmack3]] ([[User talk:Tmack3|talk]]) 08:28, 20 February 2013 (UTC)

::Ah, that's because the comic right after that, rtl, has a right-to-left character in it that flips all the proceeding text. '''[[User:Davidy22|Davidy22]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 00:13, 20 February 2013 (UTC)

Ah, ok, i see that now. When I 1st saw that RTL I just thought that it was random letters, thankyou for explaining it for me. [[User:Tmack3|Tmack3]] ([[User talk:Tmack3|talk]]) 08:28, 20 February 2013 (UTC)

It also depends on what browser you are on because on Google Chrome it was normal. [[User:Tmack3|Tmack3]] ([[User talk:Tmack3|talk]]) 09:08, 20 February 2013 (UTC)

== Do you think this question was asked by one of the xkcd people? ==

http://answers.yahoo.com/question/index?qid=20090301060752AAtYugc [[User:Tmack3|Tmack3]] ([[User talk:Tmack3|talk]]) 08:38, 20 February 2013 (UTC)

== Matthew Reilly ==

I would just like to tell everyone that I asked Matthew Reilly (the author) if he is ever scared that a velociraptor is going to attack him, and he said NO! He clearly needs to start worrying about them! [[User:Tmack3|Tmack3]] ([[User talk:Tmack3|talk]]) 10:45, 22 February 2013 (UTC)

== What can we learn section ==
First of all I love your work. I believe deeper understanding of each XKCD can make a world a better place and I thank you sincerely for starting this webpage. I wanted to ask what you think about "What can we learn?" section I've been adding to some of the pages. Thank you - [[User:E-inspired|E-inspired]] ([[User talk:E-inspired|talk]]) 13:27, 28 February 2013 (UTC)

:This site is actually the work of multiple editors working slowly and steadily to fill in explanations for all the old comics. Some of the xkcd comics are incredibly deep - comic [[956]] is such a poignant comic that digs into the DRM issue on so many levels. Your reflections on many of the comics are very much warranted and you're helping us create talk pages with high-quality opening posts, which is great for future discussion on this wiki. It'd be nice if you could refrain from putting headers in talk pages, technical limitations of the wiki make long explanation pages choke when headings are in the discussion page. Other than that, keep up the good work! '''[[User:Davidy22|Davidy²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 13:42, 28 February 2013 (UTC)

::I've put in my 2 cents to comic [[956]], and thank you for teaching me how to comment and link to other comics - [[User:E-inspired|E-inspired]] ([[User talk:E-inspired|talk]]) 13:58, 28 February 2013 (UTC)

::: FYI, you can always make pseudo-headings using a horizontal rule and a bold "header", but honestly I think a simple standard opening sentence would suffice. --[[User:Waldir|Waldir]] ([[User talk:Waldir|talk]]) 12:14, 2 March 2013 (UTC)

:Oh, and the guy who draws xkcd is called {{w|Randall Munroe}}. So many glowing things to be said about him. '''[[User:Davidy22|Davidy²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 13:44, 28 February 2013 (UTC)

::Yes, I can't thank him enough for simplifying complex issues to funny stories, I think it's exactly what our generation needs - [[User:E-inspired|E-inspired]] ([[User talk:E-inspired|talk]]) 13:58, 28 February 2013 (UTC)

:I'm in favor of a Mr. Rogers style of 'what lesson can be learned' on the talk page, but make sure your comments don't come across as sanctimonious and holier-than-thou as that can be really off-putting. [[User:Lcarsos|lcarsos]]_a ([[User talk:Lcarsos|talk]]) 19:06, 28 February 2013 (UTC)

:: You are absolutely correct, I have not thought of that, please trust me I did not do it on purpose. Thank you Mr. Lcarsos - [[User:E-inspired|E-inspired]] ([[User talk:E-inspired|talk]]) 19:55, 28 February 2013 (UTC)

Thank you David, and I apologize that I've not made it clear that by your work, I do mean your collective work (the wiki is only as good as all the people behind it). I was trying to put the headers to allow others to find the section easier in case they start looking for it, perhaps I could make a suggestion to make it a standalone section so that others would be encouraged to contribute their own understanding of lessons they have noticed from each comic. I know the lessons I've seen, but I would love to learn from others as much as I hope they can learn from me and Mr. XKCD, thank you. - [[User:E-inspired|E-inspired]] ([[User talk:E-inspired|talk]]) 13:48, 28 February 2013 (UTC)

== DING DONG THE WITCH IS DEAD ==

Hello fellow editors. Do you remember the last time we were hit by a surge of automated spam? Neither do I. ConfirmEdit has really done a number on the volume of spam that we're eating - one spam account has been created since we finished configuring confirmEdit, and zero anon edits have been spam. Zero. Can you say happiness? Can you say party? '''[[User:Davidy22|Davidy²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 14:41, 1 March 2013 (UTC)

:Hehe, I'm glad! Thanks for being so relentless on the spam-fighting all this time! Maybe we should make up a new reason to make Jeff remove the /wiki/ in the URL? ;) –[[User:St.nerol|St.nerol]] ([[User talk:St.nerol|talk]]) 18:11, 1 March 2013 (UTC)

:: Awesome news! Finally the patrolling feature will be usable: [{{fullurl:Special:RecentChanges|hideanons=1&hidepatrolled=1&from=20121204025000&days=365&limit=1000}} Unpatrolled changes by registered users] / [{{fullurl:Special:RecentChanges|hideliu=1&hidepatrolled=1&from=20121204025000&days=365&limit=1000}} Unpatrolled changes by anonymous users] :) --[[User:Waldir|Waldir]] ([[User talk:Waldir|talk]]) 12:27, 2 March 2013 (UTC)

== 1000th comic explanation!! ==

Hi all! It apparently went unnoticed that '''we have recently surpassed the mark of 1000 comic explanations!''' Some calculations based on [[:Category:Comics]] and [[Special:NewPages]] led me to the conclusion that the 1000th explanation was [[681: Gravity Wells]], created by [[User:AlexRNL]] just yesterday! Yay! This calls for a celebration, no? Congrats to [[Special:ContributionScores|everyone]] who made this happen! I'll edit [[Mediawiki:Sitenotice]] with a congratulatory message. Way to go, guys! --[[User:Waldir|Waldir]] ([[User talk:Waldir|talk]]) 16:04, 10 April 2013 (UTC)
:ps - I also took the opportunity to flesh out our [[explain xkcd|about/history page]]. Please take a look and fix/add any details I might have missed. --[[User:Waldir|Waldir]] ([[User talk:Waldir|talk]]) 16:06, 10 April 2013 (UTC)

== Style guide ==
Is there a style guide for this wiki? --[[User:PeterMortensen|PeterMortensen]] ([[User talk:PeterMortensen|talk]]) 20:14, 10 August 2013 (UTC)
:Oh, sorry, I did forget to answer here. A guide on this is not easy, many individual comics do need special layouts because they have content never can match to a style guide. But I will give a try [[Help:Style Guide]].--[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:18, 15 August 2013 (UTC)

== Adblock ==

I've whitelisted the site in adblock, but the ads are still blocked.
Anyone know what' going on here and how I can fix it?--[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 04:34, 27 September 2013 (UTC)
:Huh. I was wondering why our impression counts weren't rising. I thought it was just because this site had high turnover. I've changed the webpage that the word whitelisting links too, try the instructions there instead. Project wonderful is our ad provider, and they've been pretty good to us so far. Also, thanks for helping to support the site! '''[[User:Davidy22|{{Color|#707|David}}y²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 04:40, 27 September 2013 (UTC)
Great! I don't really mid ads as long as they aren't intrusive. Works now, Hope everyone else does it as well.--[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 05:16, 27 September 2013 (UTC)

explain xkcd:Community portal/Miscellaneous

2013-09-27T05:15:53Z

ParadoX: /* Adblock */

explain xkcd:Community portal/Miscellaneous

2013-09-27T04:34:20Z

ParadoX: /* Adblock */ new section

User:ParadoX

2013-06-26T09:02:17Z

ParadoX: Created page with "I enjoy temporal and scientific philosophy, provided it's not too complicated"

I enjoy temporal and scientific philosophy, provided it's not too complicated

Talk:545: Neutrality Schmeutrality

2013-06-26T09:01:13Z

ParadoX: Letter Count

What if instead of word count, it was determined by letter count. so insert a word with multiple spellings like "colour/color" and people will repeatedly edit and re-edit the word over and over until the servers crashed ? --[[User:ParadoX|ParadoX]] ([[User talk:ParadoX|talk]]) 09:01, 26 June 2013 (UTC)ParadoX

Talk:545: Neutrality Schmeutrality

2013-06-26T09:00:52Z

ParadoX: Letter Count