A Japanese mental health counselor recited pi to 100,000 decimal places from memory on Wednesday, setting what he claims to be a new world record.
Akira Haraguchi, 60, needed more than 16 hours to recite the number to 100,000 decimal places, breaking his personal best of 83,431 digits set in 1995, his office said Wednesday. He made the attempt at a public hall in Kisarazu, just east of Tokyo.
Pi is a physical constant defined as the ratio of a circle's circumference to its diameter.
It is usually written out to a maximum of three decimal places, as 3.141, in math textbooks. But the number, which has fascinated scientists for centuries, has no theoretical limit to the number of decimal places it can be written to. It is a constant that appears in the proofs of many equations defining the universe.
"What I am aiming at is not just memorizing figures, I am thrilled by seeking a story in pi," Haraguchi said.
The Guinness Book of Records currently lists Hiroyuki Goto, also from Japan, as the official record holder for reciting pi from memory. He recited the ratio out to 42,195 decimal places in 1995.
Guinness never entered Haraguchi's 1995 feat in its record book.
Kate White, a spokeswoman for the London-based Guinness World Records, said Haraguchi would have to make a record claim on their Web site and supply evidence, including video footage and witness statements to be included in the book.
"We would review if the evidence supports the claim. If he's done it to 100,000, he would be looking at the next world record," White said.
If he can supply evidence of his 1995 claim, that would be listed as well, White said. If he never applied in 1995, they couldn't include him in the book, White said.
Haraguchi, a psychiatric counselor and business consultant in nearby Mobara city, took a break of about 5 minutes every one to two hours, going to the rest room and eating rice balls during the attempt, said Naoki Fujii, spokesman of Haraguchi's office.
Fujii said all of Haraguchi's activities during the attempt, including his bathroom breaks, were videotaped for evidence that will later be sent for verification by the Guinness Book of Records.
Two local education officials joined 29 conference hall staff who worked in rotation to monitor Haraguchi.
Haraguchi, who began reciting pi at 9 a.m. Tuesday (0000 GMT Tuesday), reached his previous record of 83,431 digits Tuesday night, finishing exactly at 100,000 digits at 1:28 a.m. Wednesday (1628 GMT Tuesday), Fujii said.
In 2002, University of Tokyo mathematicians, aided by a supercomputer, set the world record for figuring out pi to 1.24 trillion decimal places.