Группы новостей: sci.math, sci.logic
Автор: Archimedes Plutonium <a_pluton...@iw.net>
Дата: Sun, 03 Apr 2005 13:14:35 -0500
Местное время: Вс. 3 апр 2005 21:14
Тема: Hardy & Wright fail to give a valid proof of Euclid's Infinitude of Primes
#11 --- quoting A MATHEMATICIAN'S APOLOGY, Godfrey H. Hardy, 1940,
pages 92-94 --- I can hardly do better than go back to the Greeks. I will state and prove two of the famous theorems of Greek mathematics. They are 'simple' theorems, simple both in idea and in execution, but there is no doubt at all about their being theorems of the highest class. Each is as fresh and significant as when it was discovered-- two thousand years have not written a wrinkle on either of them. Finally, both the statements and the proof can be mastered in an hour by any intelligent reader, however slender his mathematical equipment. 1. The first is Euclid's (Elements IX 20. The real origin of many theorems in the Elements is obscure, but there seems to be no particular reason for supposing that this one is not Euclid's own) proof of the existence of an infinity of prime numbers. The prime numbers or primes are the numbers (A) 2,3,5,7,11,13,17,19,23,29,... which cannot be resolved into smaller factors. (There are technical reasons for not counting 1 as a prime.) Thus 37 and 317 are prime. The primes are the material out of which all numbers are built up by multiplication: thus 666 = 2x3x3x37. Every number which is not prime itself is divisible by at least one prime (usually, of course, by several). We have to prove that there are infinitely many primes, i.e. that the series (A) never comes to an end. Let us suppose that it does, and that 2,3,5,..., P is the complete series (so that P is the largest prime); and let us, on this hypothesis, consider the number Q defined by the formula Q = (2x3x5x..xP) + 1. It is plain that Q is not divisible by any of 2,3,5,...,P; for it leaves the remainder 1 when divided by any one of these numbers. But, if not itself prime, it is divisible by some prime, and therefore there is a prime (which may be Q itself) greater than any of them. This contradicts our hypothesis, that there is no prime greater than P; and therefore this hypothesis is false. The proof is by reductio ad absurdum, and reductio ad absurdum, which Euclid loved so much, is one of a mathematician's finest weapons. It is a far finer gambit than any chess gambit: a chess player may offer the sacrifice of a pawn or even a piece, but a mathematician offers the game. --- end quoting A MATHEMATICIAN'S APOLOGY, Godfrey H. Hardy, 1940, pages 92-94 --- Hardy made two mistakes. First, he felt that Euclid did a indirect #12 --- quoting AN INTRODUCTION TO THE THEORY OF NUMBERS, Hardy & The Series of Primes Then q is not divisible by any of the numbers 2,3,5,...,p. It is Hardy and Wright fail to give a valid proof because once they formed Archimedes Plutonium Чтобы отправлять сообщения, сначала необходимо Войти.
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