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The Feynman point is a sequence of six 9s that begins at the 762nd decimal place of the decimal representation of . 〔.〕It is named after physicist Richard Feynman, who once stated during a lecture he would like to memorize the digits of until that point, so he could recite them and quip "nine nine nine nine nine nine and so on", suggesting, in a tongue-in-cheek manner, that is rational.〔.〕 ==Related statistics== is conjectured to be, but not known to be, a normal number. For a randomly chosen normal number, the probability of a specific sequence of six digits occurring this early in the decimal representation is usually only about 0.08%〔 (or more precisely, about 0.0762%). However, if the sequence can overlap itself (such as 123123 or 999999) then the probability is less. The probability of six 9s in a row this early is about 10% less, or 0.0686%. But the probability of a repetition of ''any'' digit six times starting in the first 762 digits is ten times greater, or 0.686%. One could ask the question, though, "Why talk about a repetition of ''six'' digits?" We could have had a repetition of a digit three times in the first three digits, or four times starting in the first ten digits, or five times in the first 100 digits, and so on. Each of these has about a 1% chance. So if we look at repeats up to length 12, there is about a 10% chance of finding something as surprising as Feynman's point. From this point of view, the fact that we really do find a repeat of several digits at Feynman's point is not really very surprising. The next sequence of six consecutive identical digits is again composed of 9s, starting at position 193,034.〔 The next distinct sequence of six consecutive identical digits starts with the digit 8 at position 222,299, and the digit 0 repeats six consecutive times starting at position 1,699,927. A string of nine 6s (666666666) occurs at position 45,681,781〔(Pi Search )〕 and a string of 9 9s occurs at position 590,331,982 and the next one at 640,787,382.〔(calculated with editpad lite 7 )〕 The Feynman point is also the first occurrence of four and five consecutive identical digits. The next appearance of four consecutive identical digits is of the digit 7 at position 1,589.〔 The positions of the first occurrences of 9, alone and in strings of 2, 3, 4, 5, 6, 7, 8, and 9 consecutive 9s, are 5; 44; 762; 762; 762; 762; 1,722,776; 36,356,642; and 564,665,206; respectively .〔 The number , or 2, has a string of 7 consecutive 9s starting from digit 761, a point used by Michael Hartl in his Tau Manifesto to further imply that tau is a "better" constant than pi.〔http://tauday.com/tau-digits〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Feynman point」の詳細全文を読む スポンサード リンク
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