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雙語暢銷書《艾倫圖靈傳》第9章:退隱山林(14)

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Another change was that each line on the cathode ray tube store now held forty spots, an instruction taking up twenty of them.

雙語暢銷書《艾倫圖靈傳》第9章:退隱山林(14)
另一項改變是,現在每條陰極射線管組成的“線”可以存儲40個點,每條指令佔用20個點。

These were conveniently thought of as grouped in fives, and a sequence of five binary digits as forming a single digit in the base of 32.

每5個點被劃分成一組,存儲5個二進制位,表示一個32進制的數字。

Meanwhile Newman made an ingenious choice of problem with which to demonstrate the machine.

但在演示這臺機器時,紐曼選擇了一個很不明智的例子。

as it stood with only a tiny store but with a multiplier, it was something that had been discussed at Bletchley-finding large prime numbers.

這臺機器的存儲容量還非常小,但紐曼選擇了一個在布萊切利曾經討論過的問題——尋找大素數。

In 1644, the French mathematician Mersenne had conjectured that 217-1, 219-1, 231-1, 267-1, 2127-1, 2257-1 were all prime, and that these were the only primes of that form within the range.

在1644年,數學家推測217-1、219-1,231-1,267-1,2127-1,2257-1(圖,平方號,後面還有)都是素數,而且是這個範圍內僅有的這種形式的素數。

In the eighteenth century, Euler laboriously established that 231 - 1 = 2, 146, 319, 807 was indeed prime, but the list would not have progressed further without a fresh theory.

到了18世紀,歐拉艱難地證明了231-1=2,146,319,807確實是個素數,但如果沒有新的理論來支撐,這種方法無法走得更遠。

In 1876, the French mathematician E. Lucas proved that there was a way to decide whether 2p-1 was prime by a process of p operations of squaring and taking of remainders, He announced that 2127-1 was prime.

1876年,法國數學家E·盧卡斯提出,可以通過一系列關於p的運算來檢驗2p-1是否是素數,並證明了2127-1是素數。

In 1937, the American D.H. Lehmer attacked 2257-1 on a desk calculator and after a couple of years of work showed that Mersenne had been mistaken.

1937年,美國的D·H·萊默利用臺式計算器證明了2257-1是素數, 接下來幾年的工作表明,梅森的猜想是錯誤的。

In 1949, Lucas's number was still the largest known prime, Lucas's method was tailor-made for a computer using binary numbers.

直到1949年,盧卡斯的素數依然是人們所知的最大素數,盧卡斯的方法是專門爲二進制計算機設計的。

They had only to chop up the huge numbers being squared into 40-digit sections and to program all the carrying.

所以他們需要做的工作,只是把大數分割成40位的小塊,以便於存儲。

Newman explained the problem to Tootill and Kilburn, and in June 1949, they managed to pack a program into the four cathode ray tubes and still leave enough space for working up to P = 353.

紐曼給托蒂爾和吉爾博解釋了這個問題,並且在1949年6月,他們成功地做到,在加載了程序之後,仍有足夠的空間來處理p小於353時的所有情形。

En route they checked all that Euler and Lucas and Lehmer had done, but did not discover any more primes.

他們檢查了歐拉、盧卡斯和萊默的所有工作,但卻沒能找到更大的素數注。

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