__NOTOC__ (born 1946, Miyagi Prefecture), a retired

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

ese engineer, is known for memorizing and reciting digits of pi.

Memorization of pi

He holds the current unofficial

world record A world record is usually the best global and most important performance that is ever recorded and officially verified in a specific skill, sport, or other kind of activity. The book ''Guinness World Records'' and other world records organization ...

(100,000 digits) in 16 hours, starting at 9a.m. (16:28 GMT) on October 3, 2006. He equaled his previous record of 83,500 digits by nightfall and then continued until stopping with digit number 100,000 at 1:28 a.m. on October 4, 2006. The event was filmed in a public hall in

Kisarazu is a city located in Chiba Prefecture, Japan. , the city had an estimated population of 136,023 in 63,431 households and a population density of 980 persons per km2. The total area of the city is . Geography Kisarazu is located in the midwest ...

, east of

Tokyo Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...

, where he had five-minute breaks every two hours to eat

onigiri , also known as , , or rice ball, is a Japanese food made from white rice formed into triangular or cylindrical shapes and often wrapped in ''nori''. Traditionally, an onigiri is filled with pickled ume (''umeboshi''), salted salmon, katsuobu ...

to keep up his energy levels. Even his trips to the toilet were filmed to prove that the exercise was legitimate. His previous world record of 83,431 was performed from July 1, 2005, to July 2, 2005. On

Pi Day Pi Day is an annual celebration of the mathematical constant (pi). Pi Day is observed on March 14 (3/14 in the ''month/day'' format) since 3, 1, and 4 are the first three significant figures of . It was founded in 1988 by Larry Shaw, an e ...

, 2015, he claimed to be able to recite 111,701 digits. Despite Haraguchi's efforts and detailed documentation, the

Guinness World Records ''Guinness World Records'', known from its inception in 1955 until 1999 as ''The Guinness Book of Records'' and in previous United States editions as ''The Guinness Book of World Records'', is a reference book published annually, listing world ...

have not yet accepted any of his records set. Haraguchi views the memorization of pi as "the religion of the universe", and as an expression of his lifelong quest for eternal truth.

Haraguchi's mnemonic system

Haraguchi uses a system he developed, which assigns

kana The term may refer to a number of syllabaries used to write Japanese phonological units, morae. Such syllabaries include (1) the original kana, or , which were Chinese characters (kanji) used phonetically to transcribe Japanese, the most pr ...

symbols to numbers, allowing for the memorization of pi as a collection of stories. The same system was developed by

Lewis Carroll Charles Lutwidge Dodgson (; 27 January 1832 – 14 January 1898), better known by his pen name Lewis Carroll, was an English author, poet and mathematician. His most notable works are ''Alice's Adventures in Wonderland'' (1865) and its sequel ...

to assign letters from the alphabet to numbers, and creating stories to memorize numbers. This system preceded the system above which Haraguchi developed. ;Example :0 => can be substituted by ''o, ra, ri, ru, re, ro, wo, on'' or ''oh''; :1 => can be substituted by ''a, i, u, e, hi, bi, pi, an, ah, hy, hyan, bya'' or ''byan''; The same is done for each number from 2 through 9. His stories are what he used to memorize pi.

References

External links

BBC News, Asia-Pacific

Pi World Ranking List

{{DEFAULTSORT:Haraguchi, Akira Pi-related people Japanese engineers People from Miyagi Prefecture Living people 1946 births Hitachi