Talk:1292: Pi vs. Tau

Explain xkcd: It's 'cause you're dumb.
Revision as of 09:21, 18 November 2013 by 173.245.54.86 (talk) (Wolfram Alpha appears to round some functions to about 16 decimal places.)
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I started an explanation. Hopefully others will help improve it, as I don't think it's quite adequate. 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? 141.101.97.4 07:07, 18 November 2013 (UTC)

WolframAlpha gives

4.5545743763144164456766617143366171162404440766665105335330776311513504520604364524762740226212061363100001776216741750712622557020442741544760057441760026766230424023460366047331305225241275347777145543054127636365666430221066167347236617261603127725745513663702031155234027041040155322217227723576660045156156303357534162372112340027743775672417274565277274565735325624457113522164166560115654407251403563246444122664066521461311773474046032763760765740133706761276420415672577471077133607673035331070364705651055376634161405567176532346433567731715723623721267302576735154761375545411215522177775706407470673020025353246535120744232706060324711633457720155013202527060250466252665661576165164140301645132275526153126363575631176312270212441433434206352313125326760006365710744276056412434626534152021052065172556442150110056601034116570607064550553636566432544260105637423220411372664024454234201642615033200331506013362432026775605543212342336511350621361642654426372425415023071413764173735461042064323757413414533013..._8
which does indeed have four 666 sequences. 141.101.99.254 08:06, 18 November 2013 (UTC)

This number contains 7777, 000 and 444 twice, though. 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 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

4.554574376314416445676661714336617116240444076666510533533077631151350452060436452476274022621206136310000177621674175071262255702044274154476005744176002676623042402346036604733130522524127534777714554305412763636566643022

The Unix arbitrary precision calculator gives the result without

$ echo "scale=200; obase=8; 6*a(1)" | bc -l

4.554574376314416443236234514475050122425471573015650314763354527003043167712611655054674757031331252340351471657646433317273112431020107644727072362457372164022043765215506554422014311615574251563446213636251744101107770257

Any suggestions how we can check them?

"Randall says so" is probably correct, but insufficient :-) -- Mike (talk) (please sign your comments with ~~~~)

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


Testing Wolfram Alpha with
4.55457437631441644567666171433661711624044407666651053353307763115135045206043645247627402262120613631000177621674175071262255_8 in decimal
and
4.55457437631441644567666171433661711624044407666651053353307763115135045206043645247627402262120613631000_8 in decimal
both indicate the approximation is only accurate to a limited degree.

http://www.wolframalpha.com/input/?i=4.55457437631441644567666171433661711624044407666651053353307763115135045206043645247627402262120613631000177621674175071262255_8+in+decimal http://www.wolframalpha.com/input/?i=4.55457437631441644567666171433661711624044407666651053353307763115135045206043645247627402262120613631000177621674175071262255_8+in+decimal


The method I used to get the value I put in the text was; I used the following command to generate my approximation:

echo 'scale=200; obase=8; a(1) * 6' | bc -l | tr -d ' \\\n' ; echo
which outputs

4.554574376314416443236234514475050122425471573015650314763354527003043167712611655054674757031331252340351471657646433317273112431020107644727072362457372164022043765215506554422014311615574251563446213636251744101107770257

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. 173.245.54.86 09:21, 18 November 2013 (UTC)