量子理论的发展——J.罗伯特•奥本海默纪念奖获奖演说

伤我心太深

已故的罗伯特•奥本海默教授曾是研究中心科学委员会的会员。在委员会工作期间，奥本海默对研究中心的组建起了重要的作用，他使得我们可以很容易地跟其他杰出的科学家一起成为委员会的一员。基于这个原因以及他在科学发展上的重要贡献，我们于1968年设立了一年一度的J.罗伯特•奥本海默纪念奖，并以此来嘉奖在数学、物理、化学、生物以及科学史与科学哲学中任一领域内做出过杰出成就的科学家。
当然，仅仅在校园内建立一份科学奖是不够的。下一步，也是很重要的一步，是让这份纪念奖获得值得尊敬的地位。这一点可以通过将其授予在某一领域中做出重要贡献的人。最好是，将它授予一名在一个专门的科学领域内还在世的最伟大的人，因此来转变这份纪念奖的预期效果，也即，让它不是以获奖者为荣，而是使获奖者以获得它为荣耀。正是出于这个目的，理论研究中心科学委员会推举P.A.M.狄拉克教授为J.罗伯特•奥本海默纪念奖的首位获奖者。

Introduction of Professor Dirac

狄拉克教授简介

I consider it a great honor to introduce to you rather briefly Professor Dirac. (I have to do this since all of us here are not physicists.) What I have to tell you is a representative opinion of Professor Dirac by the world of science.

我很荣幸能向大家简要地介绍一下狄拉克教授。（我之所以要这样做是因为在座的各位和我都不是物理学家。）我将要带给大家的是科学界对于狄拉克教授的一种代表性见解。

He was born in 1902 in Bristol, England. He graduated from Bristol University and obtained his Ph.D. from Cambridge University, decided to study theoretical physics at Cambridge and contributed tremendously to the then developing subject of quantum theory. Heisenberg matrix mechanics could hardly be regarded as laws of nature without the fundamental formulation of Dirac. The quantum theory as we know it and apply it today is as formulated by Dirac.
The 1920's were very exciting years for the world of physics. Great discoveries were being made almost overnight. A very rich and rewarding path was opened with the advent of quantum theory. One of the Meccas for the leading physicists of that time was in Gottingen. Young Paul Adrien Maurice Dirac was one of the members of this team—the most versatile one. By the age of 23 he had already written his classic papers which put the concepts of quantum theory on a sound mathematical basis. He reconciled the ideas of relativity with the ideas of quantum theory and invented the well-known relativistic wave equation predicting the existence of a magnetic moment of electron and hence a new fact, the spin. He further predicted that every elementary particle with a spin has its counterpart with the same mass but opposite electric charge, or that a particle has an antiparticle. It was a prophetic prediction. To the electron, the corresponding system is the positron, which was observed after the prediction in cosmic ray experiments by Anderson in 1932. Later, electron and positron pairs were actually produced in laboratory experiments. In the same way the proton and neutron should also have their corresponding antiparticles. In view of their mass content being nearly 2,000 times that of the electron, experimental observation had to await construction of a large accelerator to produce such particles by collisions of protons with nuclei. This was accomplished in 1955. His formulations of the statistics of fields and particles, his work on gravitational waves and also his prediction of magnetic monopoles stand as further monuments to his originality and deep understanding of natural phenomena.

狄拉克教授于1902年出生于英格兰的布里斯托。他毕业于布里斯托大学，并在剑桥获得哲学博士学位，此后决定在剑桥大学研究理论物理并对当时还在发展中的量子理论做出了巨大贡献。如果没有狄拉克的符号表示，海森堡的矩阵力学将很难被视为大自然的法则。我们现在知道并应用的量子力学是用狄拉克符号表示的。

二十世纪二十年代是物理界充满刺激的时代。重大发现似乎出现在一夜之间。随着量子理论的出现，一条丰富而有意义的道路敞开了。那个时候引导物理学家的麦加圣地之一，是哥廷根。年轻的狄拉克是这个队伍中的一员——而且是最有才的一位。23岁时他就已经写出他那将量子理论概念建立在牢固数学基础上的经典论文。他将相对论的思想与量子理论的思想相调和，构建出著名的相对论性波动方程，预言了电子磁矩的存在并引出一个新现象，即自旋。他进一步预言每一种自旋为 的基本粒子都有质量相同但电荷相异的对应粒子，或者说，就是每个这样的粒子都有一个反粒子。这是一个先知性的预言。对电子来说，与其相对应的是正电子，后者被安德森于1932年在宇宙射线实验中发现。之后，电子与正电子对也最终在实验室中被制造出来。同样地，质子和中子也应该有对应的反粒子。考虑到它们的质量几乎是电子的2000倍，实验观测必须等到有大型粒子加速器建造起来，这样才能靠它让质子束撞击原子核来制造质子和中子的反粒子。这项工作完成于1955年。狄拉克关于场与粒子的统计公式，他在引力波研究领域的工作还有他对磁单极子的预言都是他对自然现象的原创性及深刻的理解的象征。

The impact of Dirac's discoveries at the fundamental level has been far reaching, since even now our research in theoretical physics is guided by Dirac's ideas and his formulations. It is often customary, when one has a new idea, to ask if Dirac hasn't done something in this area. It turns out that in most instances the subject matter has been dealt with by Dirac in depth, with clarity and originality.

狄拉克诸多发现在基础理论已经具有深远影响，即便是现在，我们在理论物理方面的研究都是由狄拉克的思想和他的表示法引导的。当一个人有了什么新想法，习惯性的做法是，向别人问一下狄拉克在这个领域是否做过什么工作。结果是，大部分情况下，这个课题已经被狄拉克做过深刻而又优美且具有原创性的工作了。

His work, besides bringing him the Nobel Prize and countless other honors and prizes, had been instrumental in many others being awarded the Nobel Prize for the work they have done on his ideas and in the paths opened by Dirac. To cite just a few examples : Willis Lamb, Julian Schwinger, Eugene Wigner, Richard Feynman, S. Tomonaga, C. D. Anderson, E. Segre, O. Chamberlain and many others. (Some of these gentlemen have been guests of the Center.) What he achieved in his early 20's formed the basis on which the Nobel Foundation awarded him the Nobel Prize in 1933 at the age of 31.

狄拉克的工作除了给他自己带来了诺贝尔奖和其它无数荣誉和奖励外，也对其他一些诺贝尔奖获得者的工作提供了帮助，后者的工作是在狄拉克的思想和开创的道路上完成的。这里仅仅列举其中的几位：威利斯•兰姆、朱利安•施温格、尤因•魏格纳、理查德•费曼、朝永振一郎、C.D.安德森、E.塞雷格、O.张伯伦以及其他一些人。（这其中的一些人作为嘉宾出席了会场。）狄拉克在他人生最初的二十多年里取得的成就成为了诺贝尔基金会在1933年他31岁时授予他诺贝尔奖的依据。

Professor Dirac is known as a man, not only in physics but also in ordinary conversations, who does not make trivial remarks. There is a definite deep and well defined meaning in his every sentence, even though the sentences are not very frequent. He is endowed with all the great virtues of a great man; has no enmities, no dislikes for any human being.
Professor Dirac is a free man in the true sense of the word. This makes him also very courageous. It is a great honor for us to participate tonight in these modest ceremonies in awarding Professor Dirac the J. Robert Oppenheimer Memorial Prize.

狄拉克教授作为一个精炼的人而著称，不仅仅在物理上，在日常的交谈中也是，他从来不说废话。他所说的每一句话都具有确定的深度和明确的含义，即便那句话并不常见。他天生被赋予一个伟人的全部优点：没有憎恶，而被任何人所喜欢。
狄拉克教授是真正意义上的自由人。这使得他也非常勇敢。我们非常荣幸地能够参加今天晚上这个授予狄拉克教授J.罗伯特•奥本海默纪念奖的庄重典礼。

BEHRAM KURSUNOGLU

介绍人：BEHRAM KURSUNOGLU（译者注：这位也是一名著名的物理学家，是土耳其人，但是译者不清楚他名字的发音，故没有音译。）

Professor and Director Center for Theoretical Studies, University of Miami.

迈阿密理论研究中心教授及主管