The Craziest Thing You’ll Ever Learn About Pi
By Daniel Miessler on March 15th, 2008: Tagged as Mathematics | Science
First off, happy pi day.
According to a physicist at the Exploratorium in San Francisco, the number Pi has been calculated out to over one trillion digits. But that’s not the interesting part.
As it turns out, it’s totally overkill to get that precise with it. Dividing 22 by 7 gives an estimate that works for most everyday needs, such as carpentry and construction (it’s roughly 99% accurate). And calculating pi out to only 39 places gives truly astronomical precision.
Using pi calculated out to only 39 decimal places would allow one to compute the circumference of the entire universe to the accuracy of less than the diameter of a hydrogen atom.
Holy crap. So, yeah…I guess 39 places will be “good enough” then…
Oh, and just for a bit of trivia, Albert Einstein’s birthday is today, and he was a big fan of pi. But that’s not it. His birthday, like pi day, also falls on March 14th — otherwise known as 3.14. Einstein’s birthday on 3.14. Coincidence? I don’t think so. We all know God doesn’t play dice.:
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[ Thanks to NPR's Science Friday for the excellent show today! ]
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It’s my birthday too! Coincidence? :)
Happy pi day!
Comment by Robby Colvin — 3/15/2008 @ 5:04 am
:) Happy Birthday, Robby.
Comment by Daniel Miessler — 3/15/2008 @ 5:48 am
I don’t get how this is interesting? ‘The interesting part is that they wasted their time’ - they already knew it was pointless so why did they do? And as for the coincidence thing… ever consider that 3.14 might be WHY the 14th March is pi day, and not some uncanny weird coincidence?
Comment by Jimmy — 3/15/2008 @ 9:23 am
39 is that important? Wow. I know the first 100. I want to know at least the first 1000, just as mental exercise.
By the way, I thought I’d make it clear that Einstein wasn’t really religious. He was Jewish in heritage but not in belief. Albert Einstein used the word ‘religion’ frequently in his writings to describe his feelings towards scientific work and the cosmos, but he really didn’t mean what is traditionally thought of as ‘religion.’ In fact, Albert Einstein had a lot of sharp criticisms for the beliefs, history, and authorities behind traditional theistic religions. Einstein didn’t just reject belief in traditional gods, he rejected the entire traditional religious structures built around theism and supernatural belief.
Just thought I’d point that out.
Comment by Robert Jones — 3/15/2008 @ 10:30 am
Thanks for the fun post!
Comment by Hamilton — 3/15/2008 @ 1:10 pm
Screw you Robert Jones, you think you’re so smart. Boner
Comment by Barnaby Jones — 3/15/2008 @ 2:27 pm
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Pingback by Metaholic » The Craziest Thing You&8217;ll Ever Learn About Pi — 3/15/2008 @ 3:20 pm
Robert, I tend to agree with Barnaby Jones. Your post completely misses the point of the original article and focuses on the off-hand, humorous closing sentence. Most people would think it was a clever way to wrap things up. You apparently felt it was the author’s main point. Your poorly disguised attacks on religion are not appreciated. Quit exercising your brain memorizing digits of pi, and start exercising your tolerance of other people’s religious beliefs.
Just thought I’d point that out.
Comment by Brian Jones — 3/15/2008 @ 5:30 pm
And to the author, thank you for an interesting article. I would be interested to see the source for your diameter of the universe comment. Facts like that are fascinating, but I hate finding out they’re not true after I’ve quoted them.
I am certainly no mathematician, but I believe there are reasons other than accuracy of cirumference computations for calculating pi. In some circles, I believe it has become a kind of “king of the hill” competition. Others are looking for a (don’t tell Robert this part) “message from God”. I’m sure more than one college student has taken up the banner as part of a software algorithm exercise.
For me, I know pi out to my zip code. At a certain point, my zip code is included in the digits of pi, and I use that as a goal. In a pinch, though, I always revert back to the 22/7 approximation. It is good for quick calculations that don’t require hydrogen atom diameter accuracy.
Comment by Brian Jones — 3/15/2008 @ 5:53 pm
@Brian Jones
The source of the quote is that physicist whose email I linked to, who is also the webmaster, at the Planetarium.
Comment by Daniel Miessler — 3/15/2008 @ 6:05 pm
I’ve updated the final coincidence bit to point out that the interesting bit was Einstein’s birthday being 3.14, not pi day being 3.14. I would have thought that it was obvious that pi day was placed on that day on purpose, but people still thought it necessary to point it out.
Anyway, it should be more clear now.
Comment by Daniel Miessler — 3/15/2008 @ 6:11 pm
OK.
Could you prove mathematically the circumference of the entire universe?
I’d like to see that and please do not forget to include the expansion rate of the Universe in the mathematical proof as it is known today.
If you use 45 digits then what would be the accuracy compared to?
Please enlighten us.
Thank you
Comment by peter kopp — 3/15/2008 @ 11:02 pm
Peter, I used pi to calculate the circumference of your mom, and it was wrong, but I still did her.
Comment by AndyMC — 3/16/2008 @ 3:21 am
The universe is not round in any sense of the word, so “the circumference of the universe” is meaningless.
Comment by anon — 3/16/2008 @ 4:07 am
So, AndyMC
You are a necrophiliac then. Tsk,Tsk,Tsk.
HEY GUYS, there is a NECROPHILIAC in this site. Beware.
HE HE HE HE HE HE HE HE HE HE HE ….. ad nauseam
Comment by peter kopp — 3/17/2008 @ 7:40 pm
“Oh, and just for a bit of trivia, Albert Einstein’s birthday is today, and he was a big fan of pi. But that’s not it. His birthday, like pi day, also falls on March 14th — otherwise known as 3.14. “
What? How is that two different facts?
Comment by CorpseFish — 3/18/2008 @ 5:17 pm
to peter and n° 14, surely “the circumference of the univers is meaningles”, but take it as “a circle with the diameter of the width of the universe”. This number is of the order of 10^26 meters, to calculate the circumference you just multiply that number by pi. and that’s the circumference…with a precision of 10^-12 meters.
Comment by faaabio — 3/22/2008 @ 5:06 pm
I love when people leave comments that they think make themselves sound smart but that really just let us all know how oblivious they actually are (cough… peter). If you don’t understand a concept, don’t attack the author, ask someone who isn’t full of themselves to explain it to you. Uh.. did you all know that this there um universe is expansing?
Comment by picked apart — 3/28/2008 @ 3:17 am
Size of the universe. Assume that the universe has been expanding for its entire existence (15 billion years) with a speed around the speed of light. That is the universe has a radius of 15 billion light years. A light year is roughly 10^16 meters, giving a universe with a radius of 15*10^25 meters.
An atom has a diameter of 100pm or 10010^-12. That gives us a radius of the universe at 1.510^36 atom diameters. To allow for an error in the guestimate of the rate of expansion, the age of the universe and some minor roundings I would agree that pi with 39 decimal places should suffice under all normal circumstances.
I tend to agree with Brian that calculating pi with lots and lots of decimal places is more a quest than useful.
Comment by Henrik Bagger — 3/28/2008 @ 5:25 pm
I subscribe to Robert Jones’s point. You should read Albert Einstein book “The world as I see it” and you will find there how “religious” Einstein was. PS: My birthday is on 14.03 too and the coincidence is even greater: my birth year is 1987 while Einstein birth year is 1879. That doesn’t mean a thing for me, so we should talk about Einstein whitout supertisions connected to his name.
Comment by Radoo — 4/8/2008 @ 5:39 pm
How do we know god don’t play dice?
Comment by Mgccl — 4/14/2008 @ 8:04 pm
I have a hard time remembering long strings of numbers, so I just memorized the last ten digits of pi. I could explain how I’ve done this, but there isn’t enough room in this comment to do so.
Comment by Mark — 5/5/2008 @ 7:26 am
Although the argument of the precision when using pi to calculate precision in circles and spheres is accurate, that is not the only use for additional digits. The best use is to confirm the reliability of computers to high order terms of calculations, when the computer is being used for multi variable calculations the more terms the better. a serious case of this actually being a problem was the Pentium FDIV bug. Check it out on Wikipedia. Currently they use different methods of calculating pi to make sure that the produced string is identical to the accepted value. Oh and my birthday is June 26th, its a palindrome when written in either base 10 or base 5… or in base 625. At least I got that.
Comment by paul — 5/5/2008 @ 8:21 am
Great, thx alot
Comment by Dikey Geçiş Sınavı — 5/25/2008 @ 4:24 pm
What are the chances a mathematician would be intrigued with pi? ;) It is pretty cool, though, to be a mathematician who is born on 3.14. However, it seems likely that many mathematicians hold such honor (100/36525 chances), I’m not really sure that it’s an amazing coincidence, but it’s pretty cool.
As to the theological debate, I can hardly see that mentioning Einstein’s religious beliefs to be an act of intolerance toward believers. If you feel that way, Brian Jones, perhaps you should reevaluate your level of tolerance toward atheists. You can have your religion, but don’t think for a second that it has been verified by anyone the same way that pi has. Also, the “humorous” remark was understood to be only that, but you can’t deny the irony of concluding an article about math with a statement about myth.
Pi rocks.
Comment by B-Dog — 5/30/2008 @ 3:07 am
God doesn’t only play dice, he’s also cheating.
Comment by psyko — 6/2/2008 @ 9:25 pm
Great post.. Thank you
Comment by transpalet — 9/17/2008 @ 11:28 am
soo soo muck
Comment by ankastre — 9/17/2008 @ 11:29 am
perfect post. great
Comment by forex — 9/17/2008 @ 11:33 am
its actualyl dd/mm/yyyy, the american date system is illogical and incorrect hence theres no conincidence here he was born on the 14/3
Comment by paul — 10/28/2008 @ 9:14 pm
god doesn’t play dice, but Einstein doesn’t believe in god fool
Comment by J — 10/29/2008 @ 7:13 am
J, I’m an atheist and I know he was too. It was a joke.
Comment by Daniel Miessler — 10/29/2008 @ 2:05 pm
You’re all pricks.
Comment by Chris — 10/29/2008 @ 4:59 pm
Gods don’t exist.
Comment by Jeff — 11/4/2008 @ 11:29 pm
Robert Jones is right,Einstein didn’t believe in god. He was religious but not the way everyone else is, he never believed in a higher being you dumb fucks! Don’t only read a fucking book, but try to understand what you are reading you retarded assfucks.
Comment by aL — 11/5/2008 @ 12:01 am
OBAMA WINS!
Comment by Paul — 11/6/2008 @ 7:59 pm
My understanding of the reason for calculating pi out to such absurd lengths is to determine whether or not it ever repeats itself. (like 1/3 does) So far, no dice … but who knows what the next trillion digits may show?
Comment by Bill in Detroit — 11/7/2008 @ 5:40 am
it seems the usa is the only country (i know of) that uses the illogical date system; month-day-year
the rest of the world, including einstein’s country of birth uses the easier to understand system; day-month-year, so einstein’s abbreviated birthdate is 14.3
however mathemeticians have proposed a more logical dating system going from long to progressivly shorter units of time; year-month-day-hour-minute-second…etc
Comment by murky — 11/9/2008 @ 3:03 am
Remind me to shoot you for that doesn’t play dice comment.
Seriously, no.
Comment by asdf — 11/9/2008 @ 6:09 pm
Of course God plays dice.
Bitch still owes me $10.
Comment by Pastafaria — 11/10/2008 @ 2:38 am
[...] Apparently, dividing 22 by 7 is enough. [...]
Pingback by Pi Accuracy at tumble*jalada — 11/10/2008 @ 9:27 am
All are wrong on the Interwebs…..
The purpose of hyper accurate calc’s of the numeric value of Pi is to investigate/check whether Pi is truly a ‘transcendental’ number.
Comment by arthur doohan — 11/10/2008 @ 10:42 am
One of my favorite interview questions is: Can you tell me what number π is, in as many digits as you recall? Over the ~50 interviews I have asked it, there seems to be a distinct correlation between this answer and how well they do overall during the interview. 3.14159 appears to be the magic answer here. Someone who only knows 3.14 doesn’t have a good enough memory for this job, and someone who knows more digits (especially 12+) tends to do poorly in problem-solving scenario questions. Interesting quirk, nonetheless.
BTW, you can use the HTML entity for pi with a large font size instead of a graphic. Just use & pi;
Comment by Thomas Stromberg — 11/10/2008 @ 2:36 pm
Oh darn. So learning it to 300dp’s wasn’t sensible?
Comment by AshMashMash — 11/13/2008 @ 9:29 pm
2^2^sin(.135)+1 = 3.1402525241635
more accurate than pi or 22/7
Comment by Scotty — 11/18/2008 @ 11:47 am