Obsessed mathematicians spend a year calculating the ten trillionth digit of Pi

Hal Emmerich

From here.

It is considered by many to be the most important number in the world.

Essential to finding the circumference of a circle, Pi, valued at 3.14159265, is engrained in the minds of every school child.

But one pair of scientists have taken their obsession a step further and calculated the ten trillionth digit, doubling the record set two years ago by a super computer.
Many mathematicians try to round it down to 3.14 but Japanese IT expert Shigeru Kondo and U.S. student Alexander Yee have spent just over a year ballooning it in size.
Using a home PC that sent Kondo's house temperature shooting up to 40 degrees, they also lost half a year as their computer failed to cope with the calculations.

'We could dry the laundry immediately, but we had to pay 30,000 yen ($390) a month for electricity,' Mr Kondo's wife, Yukiko, said.

Hardware: The powerful PC used for the calculations ran so hot it sent the house temperature shooting up to 40 degrees

It was Yee who wrote the complex programme to calculate the huge number while Kondo built the super-PC, adding at least ten hard drives to make sure it could cope.
Within weeks of starting on October 16 last year the system had failed and they had to start again and then the Kondo's Japanese home was hit by the giant earthquake that shook his country, but luckily it was not damaged nor hit with a power cut.


Result: After the ten trillion digits were carefully checked it was confirmed that the final number was 5

Then further hardware failures and other problems slowed the project before it completed its task on August 26.
After that they checked the ten trillion digits were correct, and confirmed that the final number was 5.

'Over the course of the computation, there were multiple hard drive failures. Each of which required us to roll the computation back to a previous checkpoint. The result was approximately 180 days of lost time,' he said.

What was the Point??

AnamGlas

Hal Emmerich wrote: »

From here.



What was the Point??

Ten-trillionth is a milestone, they set their goal and achieved it, fair play to them.

ray giraffe

Hal Emmerich wrote: »

What was the Point??

From the horse's mouth

Because it's Pi... and because we can!

PaulieBoy

Hal Emmerich wrote: »

From here.



What was the Point??

As an awesome challenge. In addition, lots of work was done in maths that at the time seemed pointless but eventually became useful.
Beats the hell out of watching TV, I always respect people who do, over people who talk !!

Eliot Rosewater

That's pretty cool! The digits of pi are interesting. In the first 2 million digits the frequency of each individual digit 1,...,9 is about the same; less than 1% deviation if I remember correctly. Ditto for e.

Storing the 10 trillion digits would require 10,000 GB of space ... I assume they're not going to release them so!

professore

What was the Point??

That dot thingy after the "3".

professore

I wonder why they didn't use cloud computing for it - stick a few Amazon EC2 instances together and off you go. Or even distributed computing: http://distributedcomputing.info/projects.html

brianwalshcork

Avoiding cost by using local storage - doesn't sound like they were even using a raid config.
If i had to guess why the didnt use a distrbuted approach, id say that they were either avoiding complexity or wanted all the credit themselves.

locum-motion

It's a lifetime ambition of mine,
a new value of Pi to assign.
I would set it at three,
for it's simpler, you see,
than three-point-one-four-one-five-nine

Capt'n Midnight

355/113 is close enough :cool:

tfker

c

doc_17

Why? Because it's there

Capt'n Midnight

One year ? - How about 20 !
http://en.wikipedia.org/wiki/Approximations_of_%CF%80

The English amateur mathematician William Shanks, a man of independent means, spent over 20 years calculating pi to 707 decimal places. This was accomplished in 1873,

although only the first 527 were correct. LOL

His routine was as follows: He would calculate new digits all morning; and then he would spend all afternoon checking his morning's work. This was the longest expansion of pi until the advent of the electronic digital computer three-quarters of a century later.

Capt'n Midnight

http://xkcd.com/10/