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标题: TIME人物总结之Alan Turing [打印本页]

作者: tracywlz 时间: 2009-4-15 07:13:09 标题: TIME人物总结之Alan Turing

Monday, March 29, 1999
If all Alan Turing had done was answer, in the negative（否定地）, a vexing question in the arcane realm of mathematical logic, few nonspecialists today would have any reason to remember him. But the method Turing used to show that certain propositions in a closed logical system cannot be proved within that system — a corollary to the proof that made Kurt Godel famous — had enormous consequences in the world at large. For what this eccentric young Cambridge don did was to dream up an imaginary machine — a fairly simple typewriter-like contraption capable somehow of scanning, or reading, instructions encoded on a tape of theoretically infinite length. As the scanner moved from one square of the tape to the next — responding to the sequential commands and modifying its mechanical response if so ordered — the output of such a process, Turing demonstrated, could replicate logical human thought. (关于梦想)

The device（装置） in this inspired mind-experiment quickly acquired a name: the Turing machine. And so did another of Turing's insights. Since the instructions on the tape governed the behavior of the machine, by changing those instructions, one could induce the machine to perform the functions of all such machines. In other words, depending on the tape it scanned, the same machine could calculate numbers or play chess or do anything else of a comparable nature. Hence his device acquired a new and even grander name: the Universal Turing Machine.

Does this concept — a fairly rudimentary assemblage of hardware performing prodigious and multifaceted tasks according to the dictates of the instructions fed to it — sound familiar? It certainly didn't in 1937, when Turing's seminal paper, "On Computable Numbers, with an Application to the Entscheidungs problem," appeared in "Proceedings of the London Mathematical Society." Turing's thoughts were recognized by the few readers capable of understanding them as theoretically interesting, even provocative.
But no one recognized that Turing's machine provided a blueprint for what would eventually become the electronic digital computer. （不被大多数人接受）

So many ideas and technological advances converged to create the modern computer that it is foolhardy to give one person the credit for inventing it. But the fact remains that everyone who taps at a keyboard, opening a spreadsheet or a word-processing program, is working on an incarnation of a Turing machine.

Turing's 1937 paper changed the direction of his life and embroiled a shy and vulnerable man ever more directly in the affairs of the world outside, ultimately with tragic consequences.

Alan Mathison Turing was born in London in 1912, the second of his parents' two sons. His father was a member of the British civil service in India, an environment that his mother considered unsuitable for her boys. So John and Alan Turing spent their childhood in foster households in England, separated from their parents except for occasional visits back home. Alan's loneliness during this period may have inspired his lifelong interest in the operations of the human mind, how it can create a world when the world it is given proves barren or unsatisfactory. （小时候环境对成长的影响）
At 13 he enrolled at the Sherbourne School in Dorset and there showed a flair for mathematics, even if his papers were criticized for being "dirty," i.e., messy. Turing recognized his homosexuality while at Sherbourne and fell in love, albeit undeclared, with another boy at the school, who suddenly died of bovine tuberculosis. This loss shattered Turing's religious faith and led him into atheism and the conviction that all phenomena must have materialistic explanations. There was no soul in the machine nor any mind behind a brain. But how, then, did thought and consciousness arise?
After twice failing to win a fellowship at the University of Cambridge's Trinity College, a lodestar at the time for mathematicians from around the world, Turing received a fellowship from King's College, Cambridge. King's, under the guidance of such luminaries as John Maynard Keynes and E.M. Forster, provided a remarkably free and tolerant environment for Turing, who thrived there even though he was not considered quite elegant enough to be initiated into King's inner circles. When he completed his degree requirements, Turing was invited to remain at King's as a tutor. And there he might happily have stayed, pottering about with（闲逛于问题间）
problems in mathematical logic, had not his invention of the Turing machine and World War II intervened. （失败乃成功之母）
Turing, on the basis of his published work, was recruited to serve in the Government Code and Cypher School, located in a Victorian mansion called Bletchley Park in Buckinghamshire. The task of all those so assembled — mathematicians, chess champions, Egyptologists, whoever might have something to contribute about the possible permutations of（change of） formal systems — was to break the Enigma codes used by the Nazis in communications between headquarters and troops. Because of secrecy restrictions, Turing's role in this enterprise was not acknowledged until long after his death. And like the invention of the computer, the work done by the Bletchley Park crew was very much a team effort. But it is now known that Turing played a crucial role in designing a primitive, computer-like machine that could decipher at high speed Nazi codes to U-boats in the North Atlantic.
After the war, Turing returned to Cambridge, hoping to pick up the quiet academic life he had intended. But the newly created mathematics division of the British National Physical Laboratory offered him the opportunity to create an actual Turing machine, the ACE or Automatic Computing Engine, and Turing accepted. What he discovered, unfortunately, was that the emergency spirit that had short-circuited so many problems at Bletchley Park during the war had dissipated. Bureaucracy, red tape and interminable delays once again were the order of the day. Finding most of his suggestions dismissed, ignored or overruled, Turing eventually left the NPL for another stay at Cambridge and then accepted an offer from the University of Manchester where another computer was being constructed along the lines he had suggested back in 1937. (政府对科学的抑制)
Since his original paper, Turing had considerably broadened his thoughts on thinking machines. He now proposed the idea that a machine could learn from and thus modify its own instructions. In a famous 1950 article in the British philosophical journal Mind, Turing proposed what he called an "imitation test," later called the "Turing test." Imagine an interrogator in a closed room hooked up in some manner with two subjects, one human and the other a computer. If the questioner cannot determine by the responses to queries posed to them which is the human and which the computer, then the computer can be said to be "thinking" as well as the human.
Turing remains a hero to proponents of artificial intelligence（人工智能） in part because of his blithe assumption of a rosy future: "One day ladies will take their computers for walks in the park and tell each other, 'My little computer said such a funny thing this morning!'"
Unfortunately, reality caught up with Turing well before his vision would, if ever, be realized. In Manchester, he told police investigating a robbery at his house that he was having "an affair" with a man who was probably known to the burglar. Always frank about his sexual orientation, Turing this time got himself into real trouble. Homosexual relations were still a felony in Britain, and Turing was tried and convicted of "gross indecency" in 1952. He was spared prison but subjected to injections of female hormones intended to dampen his lust. "I'm growing breasts!" Turing told a friend. On June 7, 1954, he committed suicide by eating an apple laced with cyanide. He was 41. （死于社会的不理解）

作者: tracywlz 时间: 2009-4-15 07:14:58

阿兰·图灵（Alan Turing）这个名字无论是在计算机领域、数学领域、人工智能领域还是哲学、逻辑学等领域，都可谓“掷地有声”。图灵是计算机逻辑的奠基者，许多人工智能的重要方法也源自这位伟大的科学家。他在24岁时提出了图灵机理论，31岁参与了Colossus（二战时，英国破解德国通讯密码的计算机）的研制，33岁时构思了仿真系统，35岁提出自动程序设计概念，38岁设计了“图灵测试”，在后来还创造了一门新学科—非线性力学。虽然图灵去世时只有42岁，但在其短暂而离奇的生涯中的那些科技成就，已让后人享用不尽。人们仰望着这位伟大的英国科学家，把“计算机之父”、“人工智能之父”、“破译之父”等等头衔都加冕在了他身上，甚至认为，他在技术上的贡献及对未来世界的影响几乎可与牛顿、爱因斯坦等巨人比肩。
　　1912年，图灵出生在伦敦一个缺少亲情的家庭里。少年图灵的性格迥异，他内向、腼腆、胆小、软弱并患有轻度口吃，不被人接受，更不擅与人打交道。他小时候学业平平，除了一些简单的化学实验和数学题外，并无太多闪光之处。图灵的人生转机出现在他19岁进入英国剑桥皇家学院学习时，从那时起，他对数字的兴趣便一发不可收拾。在剑桥的图灵就已经是一个妇孺皆知的怪才。他的自行车链条经常在半路上掉落，要是换了别人，早就拿到车铺去修理了，而他居然在脚踏板旁装了一个小巧的机械计数器，到圈数时就停，然后歇口气换换脑子，再重新运动起来。
　　1936年，图灵在一篇名为《可计算数学》的论文中首次提出了有关计算机的理论，其中
最重要的三点为后世带来了极其深远的影响：计算机的抽象定义、“通用计算机(Universal Machine)”的设想，以及“存在任何计算机都无法解决的问题”的想法。之后，“图灵机”（Turing Machine）便诞生了。

　　当时的图灵机还只能计算有限的实数，但它的符号记录方法为以后的计算机发展奠定了基础理论，基于此，人类首次产生了符号处理的概念，并开始把研究重点转向了“可改变的编码程序”上，这就是今天软件的前身。图灵论文中的“用有限的指令和有限的存储空间可算尽一切可算之物”理论让当时所有的科学家震惊，他也因此赢得了科学界的“史密斯奖”，美国《国防软件工程杂志》也将他评为百年来影响软件发展的十位大师之一。然而，这对他来说还只是个开始。
　　1939年第二次世界大战爆发，正在为英国国家密码机构工作的图灵和其他科学家一起着手研究如何破解敌人的密码，他果然不负众望，成功破译了德国军方使用的着名通信密码系统“Enigma”（谜）。于是第一台电子图灵机被设计制造出来，做出重大贡献的图灵获得了政府颁发的OBE奖。
　　二战后，图灵被英国国家物理实验室邀请参加计算机的设计工作。1950年，图灵的一篇里程碑式的论文《机器能思考吗？》又为人类带来了一个新学科—人工智能。为了证明机器是否能够思考，他又发明了“图灵测试”（Turing Test），图灵测试在今天仍被沿用。他指出，最好的人工智能研究应该着眼于为机器编制程序，而不是制造机器。而他在论文中预测的计算机发展过程中将会出现的一些问题，至今仍未被解决。
　　尽管才华横溢的图灵在许多领域都有着不凡的成就，但因其在计算机和人工智能方面的突出贡献，人们还是喜欢称他为“人工智能之父”或“计算机之父”。同样有着“计算机之父”称号的冯·诺依曼的助手弗兰克尔在一封信中写到：“……计算机的基本概念属于图灵。按照我的看法，冯·诺依曼的基本作用是使世界认识了由图灵引入的计算机基本概念……”

　　为了纪念，图灵的事迹已被拍成影视剧，写成小说、诗歌等，以他名字命名的“图灵奖”也已成为计算机界的诺贝尔奖。牛津大学着名数学家安德鲁·哈吉斯在为图灵写的一部脍炙人口的传记《谜一样的图灵》（Alan Turing: The Enigma）中这样描述到：“图灵似乎是上天派来的一个使者，匆匆而来，匆匆而去，为人间留下了智慧，留下了深邃的思想，后人必须为之思索几十年、上百年甚至永远。”

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