Japanese man gains world record for pi calculation

A Japanese businessman using a home-built computer has taken calculations of the mathematical concept of "pi" to the trillions of digits and won a world record for his labours.                                           

Shigeru Kondo, a systems engineer in his 50s at a food company in the central Japanese prefecture of Nagano, in August calculated pi -- the ratio of a circle's circumference to its diameter -- to five trillion digits, almost doubling the accuracy of the previous world record. 

Last week, the calculation was recognised by Guinness World Records with a certificate mailed to Kondo, who said he began the calculations simply as a hobby. 

"I really want to praise my computer, which calculated continuously for three months without complaint," Kondo told the Chunichi Shimbun daily.  

He shared the honour with a US computer science student, Alexander Yee, who programmed the application software and liaised with Kondo by e-mail.         

Using parts from local warehouses and online stores, Kondo assembled a desktop computer that featured two high-end Intel processers and 20 external hard-drives.

After 90 days of non-stop processing, Kondo obtained a string of five trillion numbers that defined pi. He verified the result with different methods, which alone took 64 hours.                          

The previous record, set by a French software consultant in January 2010, was around 2.7 trillion digits.                             

Calculating a more accurate pi, which is believed to go on forever, has been a challenge for scholars for thousands of years, ever since the parameter was used in ancient Egypt.

Kondo is now trying to calculate pi to 10 trillion digits.  

"If everything goes well, I should reach that point in July. I'm really looking forward to that," he said.