理查德·费曼Richard Feynman

理查德·费曼的父母是Melville费曼和Lucille Phillips。Melville出生于白俄罗斯明斯克的一个犹太家庭，五岁时随父母移民到美国。他是一位商人，尝试过许多不同类型的生意，但不太成功。很明显，他的才能不在商业上，而在科学上，这是他着迷的学科，但他从未有机会以此谋生。Lucille Phillips出生在美国的一个犹太家庭。Lucille的父亲从波兰移民而来，她的母亲也来自波兰移民家庭。她接受过小学教师培训，但在1917年与Melville结婚，尚未从事职业。

结婚后，露西尔和梅尔维尔费曼搬进了曼哈顿的一套公寓，第二年，他们的第一个孩子费曼出生了。梅尔维尔希望他的第一个孩子是儿子，他也希望他成为一名科学家，所以当他得到想要的儿子时欣喜若狂，他在费曼的整个童年时期尽一切努力使他对科学产生兴趣。6写道：-

梅尔维尔给家庭的礼物是知识和严肃。幽默和讲故事来自露西尔。

当费曼五岁时，悲剧降临到这个家庭，因为露西尔和梅尔维尔有了第二个儿子，他在四周大时去世了。这意味着一种悲伤笼罩着家庭，这一定极大地影响了年幼的费曼。此后，他一直是一个独生子，直到他九岁时他的妹妹琼出生。在这些年里，家庭搬了几次家，但当费曼十岁时，他们定居在远洛克威。

费曼，或者他的朋友们叫他里蒂，从《大英百科全书》学到了大量科学知识，并在学校遇到初等数学之前自学了它。他还在家里的房间里设立了一个实验室，在那里进行电学实验。特别是，他用灯泡连接电路，发明了防盗警报器，并拆开收音机修理损坏的电路。当他进入远洛克威高中时，他的兴趣几乎完全是数学和科学。此时他对艺术类科目几乎没有兴趣[4]：-

我总担心自己像个娘娘腔；我不想显得太柔弱。在我看来，真正的男人从不关注诗歌之类的东西。

在学校里，费曼以一种极不寻常的方式接触数学。基本上，他喜欢娱乐数学，并从中获得了极大的乐趣。他在自己的时间里学习了很多数学，包括三角学、微分和积分以及复数，远早于他在正规教育中遇到这些主题。意识到数学符号的重要性后，他为sin、cos、tan、$f (x)$等发明了自己的符号，他认为这比标准符号好得多。然而，当一个朋友请他解释一段数学时，他突然意识到符号不可能是个人事务，因为人们需要它来交流。他非常喜欢数学竞赛，在学校里是个真正的明星。在Far Rockaway高中的最后一年，他赢得了纽约大学数学锦标赛。

离开学校后，他申请了几所大学去那里学习。人们会以为他申请的每所大学都会热情地为他提供名额，但事情并没有那么容易。尽管他在数学和科学方面的成绩很突出，但他在其他科目上的表现要差得多。还有一个“问题”是他是犹太人，这在当时的美国确实是个问题，因为大学对录取的犹太人数量有配额。他参加了哥伦比亚大学的入学考试，他们拒绝了他。他从未真正原谅他们收取了他15美元然后拒绝了他。然而，他被麻省理工学院录取了。

他于1935年进入麻省理工学院，经过四年的学习，于1939年获得学士学位。他去那里学习数学，但是，尽管他发现课程很容易，他却越来越担心当时课程所特有的抽象性和缺乏应用。他在第一年学习时读了亚瑟·爱丁顿的Mathematical Theory of Relativity，觉得这就是他想从数学中得到的东西。他的数学讲师向他提出了这样一种观点：人们为数学本身而研究数学，所以费曼换了课程，学习电气工程。很快他又换了，这次转向了物理。有趣的是，如果费曼选修了弗雷德·霍伊尔大约同时期在剑桥所修的数学课程，他会发现那正是他想要的。

费曼在MIT学习的物理课程不是标准的。他在第二年选修了为研究生开设的理论物理导论。当时没有关于量子力学的课程，而这是费曼非常渴望学习的主题，因此，1936年春天，他与本科同学T A Welton一起开始阅读现有的文本。1936年夏天，他们回到各自家中，两人交换了一系列非凡的信件，试图发展一种时空版本，其中（引自其中一封信——见[6]）：-

……电现象是空间度规的结果，就像引力现象一样。

到1937年，费曼正在阅读保罗·狄拉克的The principles of quantum mechanics，并看到他那极具独创性的思想如何融入保罗·狄拉克的方法。事实上，保罗·狄拉克成为费曼一生中最尊敬的科学家。

我们在上面提到费曼回家度假。事实上，他每年夏天都申请贝尔电话实验室的暑期工作，但尽管有最高的推荐，却总是被拒绝。虽然永远无法证明，但除了他是犹太人之外，似乎没有其他原因会导致他被拒绝。

当他在麻省理工学院度过的四年出色本科生涯接近尾声时，他开始考虑攻读博士学位。由于他在麻省理工学院过得非常愉快，并且也认为它是领先的学府，他去找物理系主任弗瑞兹·约翰斯莱特，请求留下来攻读博士学位课程。斯莱特告诉他，为了他自己好，他必须离开，并建议他去普林斯顿。

尽管普林斯顿的Harry Smyth收到了Slater的个人推荐，但费曼能否被录取仍不明朗。他的物理和数学成绩是所有人中最好的，但另一方面，他在历史、文学和美术方面几乎垫底。还有一点对他不利——那就是他是犹太人。Smyth写道：-

费曼是犹太人？我们没有明确的规定反对犹太人，但由于安置他们很困难，我们必须使我们系中犹太人的比例保持得相当小。

在Slater进一步来信后，费曼被普林斯顿录取了。他在普林斯顿的博士工作由John Wheeler指导，在发现安娜·约翰逊·佩尔·惠勒给他的第一个问题相当棘手后，他回到了在MIT时思考过的一些想法。他在普林斯顿做的第一次研讨会的听众包括阿尔伯特·爱因斯坦、沃尔夫冈·泡利和冯·诺伊曼。沃尔夫冈·泡利在结束时说[4]：-

我认为这个理论不可能正确……

回想起来，费曼认为沃尔夫冈·泡利一定立刻看出了困难，因为在费曼花了很长时间研究它之后，他也认为它不令人满意。然而，他随后继续使用最小作用量原理发展了一种新的量子力学方法。他用一个基于映射到时空中的粒子相互作用的模型取代了詹姆斯·克拉克·麦克斯韦的电磁波模型。Gleick写道[6]：-

这是费曼接近其能力巅峰的时期。在二十三岁时……地球上没有哪位物理学家能比得上他对理论科学原生材料的充沛掌控力。这不仅仅是在数学上的才能（尽管已经清楚……从惠勒-费曼合作中产生的数学机器超出了惠勒自身的能力）。费曼似乎对方程背后的实质拥有一种令人畏惧的轻松，就像同年龄的阿尔伯特·爱因斯坦，就像苏联物理学家列夫·朗道——但很少有人能如此。

他于1942年在普林斯顿获得博士学位，但在此之前美国已加入第二次世界大战。

费曼在普林斯顿大学（1941-42）参与原子弹项目，随后在洛斯阿拉莫斯（1943-45）工作。当他在研究的最后一年被接洽参与该项目时，他的第一反应是非常明确的拒绝，因为他当时正进入学位论文工作的最后阶段[4]：-

……我回到我的学位论文——大约三分钟。然后我开始在地板上来回踱步，思考这件事。德国人有希特勒，开发原子弹的可能性显而易见，而他们可能先于我们开发出来的可能性非常令人恐惧。

费曼在普林斯顿开始参与曼哈顿计划，发展一种如何将铀235与铀238分离的理论，而他的学位论文导师惠勒前往芝加哥，与恩里科·费米一起研究第一座核反应堆。在惠勒缺席期间，尤金·维格纳建议费曼撰写他的学位论文，在惠勒和尤金·维格纳审查了这项工作后，他于1942年6月获得博士学位。

费曼此时有一个困难的个人问题。他多年的女友阿琳·格林鲍姆被诊断出患有肺结核，他的家人反对他们结婚。在他被授予博士学位后不久，费曼与阿琳结婚，没有家人出席。结婚后不久，费曼前往新建的洛斯阿拉莫斯基地从事原子弹项目工作。他非凡的能力很快使他被任命为理论部主任。阿琳于1945年在炸弹首次试验前去世。费曼后来又结了两次婚，并与第三任妻子育有两个孩子。

第二次世界大战后，1945年秋，费曼被任命为康奈尔大学理论物理学教授。起初他专注于教学，将研究搁置一旁。洛斯阿拉莫斯工作的压力，加上目睹妻子健康恶化的个人压力，已经造成了损害。他写道[4]：-

如果你在教一个班，你可以思考那些你非常熟悉的基础内容。这些东西有点有趣且令人愉快。重新思考它们没有任何坏处。有没有更好的方式来呈现它们？基础内容容易思考；如果你想不出新的想法，也没有坏处；你之前对它的思考对课堂来说已经足够好了。如果你确实想到了新东西，你会相当高兴自己有了一种新的看待它的方式。

他收到了其他大学的职位邀请，但觉得自己作为一个非研究者，根本无法考虑这些职位。突然，从事研究的渴望再次袭来，他回到了二战前正在研究的电动力学量子理论。

1950年，费曼接受了加州理工学院理论物理学教授的职位。由于在收到聘书之前他已经计划了休假，因此他得以安排在新职位的最初十个月在巴西度过。他在加州理工学院度过了余下的职业生涯，并于1959年被任命为该校的费曼 Chace Tolman理论物理学讲席教授。

费曼的主要贡献是在量子力学方面，这是在他博士论文工作的基础上发展起来的。他引入了图表（现在称为费曼图），这些图表是描述相互作用粒子系统行为所需数学表达式的图形类比。他于1965年与朱利安·施温格和朝永共同获得了诺贝尔奖：-

……因在量子电动力学方面的基础性工作，以及对基本粒子物理学的深远影响。

关于粒子自旋和‘部分子’理论的其他工作，导致了当前的夸克理论，这些工作对于推动粒子物理学的理解具有基础性意义。

1979年初，费曼的健康状况恶化，他接受了胃癌手术。手术非常成功，医生们相信他不会复发。康复后，他享受作为著名公众人物的瞩目，当《4》一书意外成为畅销书时，这一角色更加突出。他最后一项主要任务是作为调查1986年1月28日星期二挑战者号航天飞机爆炸原因委员会的成员。这次调查的科学与政治交织的迷人故事，在费曼自己的话中记载于5。这对费曼来说是一段非常艰难的时期，因为在整个调查过程中，他的健康状况不断恶化。1987年底，他的腹部再次发现癌症。他去世后，钱德勒于1988年2月17日在17中写道：-

费曼在与腹部癌症抗争八年后，于加州大学洛杉矶分校医疗中心去世。他是一位受欢迎且精力充沛的讲师，尽管生病，仍继续在加州理工学院任教，直到两周前。

费曼的著作中有许多杰出的作品是从讲课课程发展而来的。例如Quantum Electrodynamics（1961）和The Theory of Fundamental Processes（1961）、The Feynman Lectures on Physics（1963-65）（3卷）、The Character of Physical Law（1965）和QED: The Strange Theory of Light and Matter（1985）。

在[6]中，Gleick描述了费曼的科学方法：-

他的许多见证者都观察到他的思想飞翔的绝对自由，然而当费曼谈论自己的方法时，不是自由而是约束……对费曼来说，科学想象力的本质是一条强大且几乎令人痛苦的规则。科学家所创造的东西必须与现实相符。它必须与已知的东西相符。他说，科学创造力是穿着紧身衣的想象力……和声进行的规则为莫扎特制造了一个像十四行诗为莎士比亚制造的那样不可动摇的笼子。同样不可动摇，也同样解放——因为后来的批评家在结构与自由、严谨与创造性的对位中发现了创造者的天才。

费曼因其工作获得了许多荣誉。他当选为美国物理学会、美国科学促进会、National Academy of Science和伦敦皇家学会的成员。他获得的奖项包括阿尔伯特·爱因斯坦奖（1954）和劳伦斯奖（1962）。

至于费曼的性格，[17]中这样描述：-

他以其永不满足的好奇心、温和的机智、聪明的头脑和爱玩的气质而广为人知。

⟦N1⟧在6中将他描述为：-

……在计算方面聪明得令人费解，对文献却奇怪地无知，充满激情。

Richard Feynman's parents were Melville Feynman and Lucille Phillips. Melville was born into a Jewish family in Minsk, Belarus, and emigrated with his parents to the United States when he was five years old. He was a business man who tried, not too successfully, many different types of business. It is clear that his talents were not in business but rather in science which was the subject that fascinated him but he never had the opportunity to make a career from it. Lucille Phillips was born in the United States into a Jewish family. Lucille's father had emigrated from Poland and her mother also came from a family of Polish immigrants. She trained as a primary school teacher but married Melville in 1917 before taking up a profession.

After their marriage Lucille and Melville Feynman moved into a Manhattan apartment and, in the following year, their first child Richard was born. Melville wanted his first child to be a son and he also wanted him to become a scientist so, overjoyed when he got the son he wanted, he did all he could to interest Richard in science throughout his childhood. Gleick writes [6]:-

Melville's gift to the family was knowledge and seriousness. Humour and storytelling came from Lucille.

Tragedy struck the family when Richard was five years old for Lucille and Melville had a second son who died when four weeks old. It meant that a sadness fell over the household which must have greatly affected the young Richard. After this, he remained an only child until his sister Joan was born when he was nine years old. The family moved several times during these years but when Richard was ten they settled in Far Rockaway.

Richard, or Ritty as his friends called him, learnt a great deal of science from Encyclopaedia Britannica and taught himself elementary mathematics before he encountered it at school. He also set up a laboratory in his room at home where he experimented with electricity. In particular he wired circuits with light bulbs, he invented a burglar alarm, and he took radios apart to repair damaged circuits. When he entered Far Rockaway High School his interests were almost entirely mathematics and science. He found little liking for arts type subjects at this time [4]:-

I always worried about being a sissy; I didn't want to be too delicate. To me, no real man ever paid any attention to poetry and such things.

At school Feynman approached mathematics in a highly unconventional way. Basically he enjoyed recreational mathematics from which he derived a large amount of pleasure. He studied a lot of mathematics in his own time including trigonometry, differential and integral calculus, and complex numbers long before he met these topics in his formal education. Realising the importance of mathematical notation, he invented his own notation for sin, cos, tan, $f (x)$ etc. which he thought was much better than the standard notation. However, when a friend asked him to explain a piece of mathematics, he suddenly realised that notation could not be a personal matter since one needed it to communicate. He really enjoyed mathematics competitions and was a real star in his school. In his final year at Far Rockaway High School he won the New York University Math Championship.

After leaving school he applied to several universities to study there. One would have expected every university to which he applied would enthusiastically offer him a place but it was not that easy. Although his grades in mathematics and science were outstanding, he had performed much less well in other subjects. There was also the "problem" that he was a Jew, which really was a problem in the United States at this time with universities having quotas on the number of Jews they admitted. He sat an entrance examination for Columbia University and they turned him down. He never quite forgave them for charging him 15 dollars and then rejecting him. He was accepted, however, by the Massachusetts Institute of Technology.

He entered MIT in 1935 and, after four years study, obtained his B.Sc. in 1939. He went there to study mathematics but, although he found the courses easy, he became increasingly worried by the abstraction and lack of applications which characterised the course at this time. He read Eddington's Mathematical Theory of Relativity while in his first year of studies and felt that this was what he wanted from mathematics. His mathematics lecturers presented him with the view that one did mathematics for its own sake so Feynman changed courses, taking electrical engineering. Very quickly he changed again, this time moving into physics. It is interesting to think that had Feynman taken the mathematics course at Cambridge which Hoyle took around the same time, he would have found it exactly what he wanted.

The physics course that Feynman took at MIT was not the standard one. He took Introduction to Theoretical Physics, a class intended for graduate students, in his second year. There was no course on quantum mechanics, a topic that Feynman was very keen to study, so together with a fellow undergraduate, T A Welton, he began to read the available texts in the spring of 1936. Returning to their respective homes in the summer of 1936 the two exchanged a series of remarkable letters as they tried to develop a version of space-time where (quoted from one of the letters - see [6]):-

... electrical phenomena [are] a result of the metric of a space in the same way that gravitational phenomena are.

By 1937 Feynman was reading Dirac's The principles of quantum mechanics and seeing how his highly original ideas fitted into Dirac's approach. In fact Dirac became the scientist who Feynman most respected throughout his life.

We mentioned above that Feynman went home for his vacations. In fact he applied for summer jobs at the Bell Telephone Laboratories every summer but was always refused a position there despite the highest recommendations. Although it can never be proved, there seems no other reason that he would be turned down other than that he was Jewish.

As he approached the end of his remarkable four undergraduate years at MIT he began to think about studying for his doctorate. Since he had been so happy at MIT and also believing it to be the leading institution, he approached the head of physics, John Slater, requesting that he stay on to take a Ph.D. course. Slater told him that for his own good he had to move and he suggested Princeton.

Despite the personal recommendation that Harry Smyth at Princeton received from Slater, it was not obvious that Feynman would be accepted. He had the best grades in physics and mathematics that anyone had seen, but on the other hand he was close to the bottom in history, literature and fine arts. He had one other thing going against him - namely that he was Jewish. Smyth wrote:-

Is Feynman Jewish? We have no definite rule against Jews but have to keep their proportion in our department reasonably small because of the difficulty of placing them.

After further letters from Slater, Feynman was accepted by Princeton. His doctoral work at Princeton was supervised by John Wheeler, and after finding the first problem that Wheeler gave him rather intractable, he went back to ideas he had thought about while at MIT. The first seminar that he gave at Princeton was to an audience which included Einstein, Pauli and von Neumann. Pauli said at the end [4]:-

I do not think this theory can be right ...

In retrospect, Feynman thought that Pauli must have seen difficulties at once, for after Feynman had spent a long time working on it, he too thought that it was not satisfactory. However, he then went on to develop a new approach to quantum mechanics using the principle of least action. He replaced the wave model of electromagnetics of Maxwell with a model based on particle interactions mapped into space-time. Gleick writes [6]:-

This was Richard Feynman nearing the crest of his powers. At twenty-three ... there was no physicist on earth who could match his exuberant command over the native materials of theoretical science. It was not just a facility at mathematics (though it had become clear ... that the mathematical machinery emerging from the Wheeler-Feynman collaboration was beyond Wheeler's own ability). Feynman seemed to possess a frightening ease with the substance behind the equations, like Einstein at the same age, like the Soviet physicist Lev Landau - but few others.

He received his doctorate from Princeton in 1942 but before this time the United States had entered World War II.

Feynman worked on the atomic bomb project at Princeton University (1941-42) and then at Los Alamos (1943-45). When he was approached during his final year of research to take part in the project his first reaction had been a very definite no since he was entering the final stages of work for his thesis at the time [4]:-

... I went back to my thesis - for about three minutes. Then I began to pace the floor and think about the thing. The Germans had Hitler and the possibility of developing an atomic bomb was obvious, and the possibility that they would develop it before we did was very much of a fright.

Feynman began work on the Manhattan project at Princeton developing a theory of how to separate Uranium 235 from Uranium 238, while his thesis supervisor Wheeler went to Chicago to work with Fermi on the first nuclear reactor. Wigner, in Wheeler's absence, advised Feynman to write up his thesis and after Wheeler and Wigner examined the work he received his doctorate in June 1942.

Feynman had a difficult personal problem at this time. His girlfriend of many years, Arlene Greenbaum, had been diagnosed as having tuberculosis and his family opposed their marriage. Shortly after he was awarded his doctorate Feynman married Arlene with no family members present. Shortly after his marriage Feynman went to the newly constructed Los Alamos site to work on the atomic bomb project. His remarkable abilities soon led to him being appointed as head of the theoretical division. Arlene died in 1945 just before the first test of the bomb. Feynman would marry twice more and have two children with his third wife.

After World War II, in the autumn of 1945, Feynman was appointed as a professor of theoretical physics at Cornell University. At first he devoted himself to teaching and put his research aside. The pressure of the work at Los Alamos, together with the personal stress of watching his wife's health decline, had taken its toll. He wrote [4]:-

If you're teaching a class, you can think about the elementary things that you know very well. These things are kind of fun and delightful. It doesn't do any harm to think them over again. Is there a better way to present them? The elementary things are easy to think about; if you can't think of a new thought, no harm done; what you thought about it before is good enough for the class. If you do think of something new, you're rather pleased that you have a new way of looking at it.

He received offers of posts at other universities but felt that as a non-researcher he could not even consider them. Suddenly the desire to undertake research hit him again and he returned to the quantum theory of electrodynamics that he was working on before World War II.

In 1950 Feynman accepted a position as professor of theoretical physics at the California Institute of Technology. Since he had already planned a sabbatical leave before receiving the offer, he was able to arrange to spend the first ten months of his new appointment in Brazil. He remained at Cal tech for the rest of his career, being appointed Richard Chace Tolman Professor of Theoretical Physics there in 1959.

Feynman's main contribution was to quantum mechanics, following on from the work of his doctoral thesis. He introduced diagrams (now called Feynman diagrams) that are graphic analogues of the mathematical expressions needed to describe the behaviour of systems of interacting particles. He was awarded the Nobel Prize in 1965, jointly with Schwinger and Tomonoga:-

... for fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles.

Other work on particle spin and the theory of 'partons' which led to the current theory of quarks were fundamental in pushing forward an understanding of particle physics.

In early 1979 Feyman's health had deteriorated and he had surgery for stomach cancer. This was very successful and his doctors believed that he would not suffer a recurrence. After his recovery he enjoyed the limelight as a famous public figure, a role which was enhanced when the book [4] became a surprise best seller. His final major task was as a member of a committee set up to investigate the cause of the explosion on the space shuttle Challenger on Tuesday 28 January 1986. The fascinating story of the science and politics of this investigation is told in Feyman's own words in [5]. It was a very difficult time for Feyman since throughout the investigation his health was deteriorating. Near the end of 1987 cancer was found again in his abdomen. After his death, Chandler wrote on 17 February 1988 in [17]:-

Feynman, who died at the University of California at Los Angeles Medical Center after an eight-year battle with abdominal cancer, was a popular and energetic lecturer who, despite his illness, continued to teach at the California Institute of Technology until two weeks ago.

Feynman's books include many outstanding ones which evolved out of lecture courses. For example Quantum Electrodynamics (1961) and The Theory of Fundamental Processes (1961), The Feynman Lectures on Physics (1963-65) (3 volumes), The Character of Physical Law (1965) and QED: The Strange Theory of Light and Matter (1985).

In [6] Gleick described Feynman's approach to science:-

So many of his witnesses observed the utter freedom of his flights of thought, yet when Feynman talked about his own methods not freedom but constraint ... For Feynman the essence of scientific imagination was a powerful and almost painful rule. What scientists create must match reality. It must match what is already known. Scientific creativity, he said, is imagination in a straitjacket ... The rules of harmonic progression made for Mozart a cage as unyielding as the sonnet did for Shakespeare. As unyielding and as liberating - for later critics found the creator's genius in the counterpoint of structure and freedom, rigour and inventiveness.

Feynman received many honours for his work. He was elected to the American Physical Society, the American Association for the Advancement of Science, the National Academy of Science, and the Royal Society of London. Among the awards he received were the Albert Einstein Award (1954) and the Lawrence Award (1962).

As to Feynman's character, he was described in [17] as follows:-

He was widely known for his insatiable curiosity, gentle wit, brilliant mind and playful temperament.

Gleick [6] describes him as:-

... mystifyingly brilliant at calculating, strangely ignorant of the literature, passionate.