who held the record for most memorized digits the longest
Akira Haraguchi He holds the current unofficial world record (100,000 digits) in 16 hours, starting at 9 a.m (16:28 GMT) on October 3, 2006 and having recited up to 83,431 digits by nightfall, stopping with digit number 100,000 at 1:28Â a.m. on October 4, 2006. The event was filmed in a public hall in Kisarazu, east of Tokyo, where he had five-minute breaks every two hours to eat onigiri to keep up his energy levels. Even his trips to the toilet were filmed to prove that the exercise was legitimate. Haraguchi's previous world record (83,431), was performed from July 1, 2005 to July 2, 2005. On Pi Day, 2015, he claimed to be able to recite 111,701 digits.[1]
Mechanical calculator Surviving notes from Wilhelm Schickard in 1623 reveal that he designed and had built the earliest of the modern attempts at mechanizing calculation. His machine was composed of two sets of technologies: first an abacus made of Napier's bones, to simplify multiplications and divisions first described six years earlier in 1617, and for the mechanical part, it had a dialed pedometer to perform additions and subtractions. A study of the surviving notes shows a machine that would have jammed after a few entries on the same dial,[1] and that it could be damaged if a carry had to be propagated over a few digits (like adding 1 to 999).[2] Schickard abandoned his project in 1624 and never mentioned it again until his death eleven years later in 1635.