题目：量子电动力学时空观的发展 - 理查德·费曼（Richard P. Feynman）

我们习惯于在科学期刊上发表文章时，尽可能地完成工作，掩盖所有的痕迹，不担心死胡同，或者描述你最先是如何产生错误想法的，等等。 所以没有任何地方可以以有尊严的方式发表你为了完成这项工作而实际做了什么，尽管最近，人们对这类事情有些兴趣。 由于获奖是个人的事情，如果我个人谈论我与量子电动力学的关系，而不是以精致和完成的方式讨论主题本身，我认为在这种特殊情况下我可以被原谅。 而且物理学奖有三个人，要是都说量子电动力学本身，估计会觉得无聊。 所以，我今天想告诉你的是事件的来龙去脉，实际上是想法的来龙去脉，发生了，我最终从另一端得出一个未解决的问题，最终获奖。

我意识到一篇真正的科学论文会更有价值，但这样的论文我可以在正规期刊上发表。 因此，我将以这次诺贝尔演讲为契机，做一些价值较低但我在其他地方做不到的事情。 我以另一种方式请求您的宽恕。 我将包括一些轶事的细节，这些轶事既没有科学价值，也没有理解思想发展的价值。 包括它们只是为了使讲座更有趣。

我研究这个问题大约八年，直到 1947 年最终发表。事情的开始是在麻省理工学院，当时我还是一名本科生，阅读已知的物理知识，慢慢了解人们担心的所有这些事情，关于并最终意识到当时的根本问题是电学和磁学的量子理论并不完全令人满意。 这是我从海特勒和狄拉克的书中收集到的。这些书中的言论给我带来了启发；不是通过仔细证明和演示和计算所有内容的部分，因为我不能很好地理解那些。年轻的我能理解的是关于这没有任何意义的评论，我仍然记得狄拉克书中的最后一句话，“似乎这里需要一些本质上新的物理思想。 ” 所以，我把这当作挑战和灵感。 我也有个人的感觉，既然他们没有得到我想解决的问题的满意答案，我就不必太关注他们做了什么。

然而，我从文献中了解到有两件事是量子电动力学理论困难的根源：第一个是电子与自身相互作用的无穷能量，此困难甚至在经典理论中也存在；另一个困难来自与场中无穷多的自由度有关的无穷。 正如我当时所理解的那样（几乎是我所记得的那样）这只是困难，如果你量化场的谐波振荡器（比如在一个盒子中）每个振荡器的基态能量为（½）并且有随着频率 w 的增加，盒子中的模式数量为无穷，因此盒子中的能量为无穷。 我现在意识到那不是对中心问题的完全正确的陈述； 它可以简单地通过改变测量能量的零来消除。无论如何，我相信困难是由于电子作用于自身和场的无穷自由度的结合而产生的。

。。。

二，原文

The Development of the Space-Time View of Quantum Electrodynamics

We have a habit in writing articles published in scientific journals to make the work as finished as possible, to cover all the tracks, to not worry about the blind alleys or to describe how you had the wrong idea first, and so on. So there isn’t any place to publish, in a dignified manner, what you actually did in order to get to do the work, although, there has been in these days, some interest in this kind of thing. Since winning the prize is a personal thing, I thought I could be excused in this particular situation, if I were to talk personally about my relationship to quantum electrodynamics, rather than to discuss the subject itself in a refined and finished fashion. Furthermore, since there are three people who have won the prize in physics, if they are all going to be talking about quantum electrodynamics itself, one might become bored with the subject. So, what I would like to tell you about today are the sequence of events, really the sequence of ideas, which occurred, and by which I finally came out the other end with an unsolved problem for which I ultimately received a prize.

I realize that a truly scientific paper would be of greater value, but such a paper I could publish in regular journals. So, I shall use this Nobel Lecture as an opportunity to do something of less value, but which I cannot do elsewhere. I ask your indulgence in another manner. I shall include details of anecdotes which are of no value either scientifically, nor for understanding the development of ideas. They are included only to make the lecture more entertaining.

I worked on this problem about eight years until the final publication in 1947. The beginning of the thing was at the Massachusetts Institute of Technology, when I was an undergraduate student reading about the known physics, learning slowly about all these things that people were worrying about, and realizing ultimately that the fundamental problem of the day was that the quantum theory of electricity and magnetism was not completely satisfactory. This I gathered from books like those of Heitler and Dirac. I was inspired by the remarks in these books; not by the parts in which everything was proved and demonstrated carefully and calculated, because I couldn’t understand those very well. At the young age what I could understand were the remarks about the fact that this doesn’t make any sense, and the last sentence of the book of Dirac I can still remember, “It seems that some essentially new physical ideas are here needed.” So, I had this as a challenge and an inspiration. I also had a personal feeling, that since they didn’t get a satisfactory answer to the problem I wanted to solve, I don’t have to pay a lot of attention to what they did do.

I did gather from my readings, however, that two things were the source of the difficulties with the quantum electrodynamical theories. The first was an infinite energy of interaction of the electron with itself. And this difficulty existed even in the classical theory. The other difficulty came from some infinites which had to do with the infinite numbers of degrees of freedom in the field. As I understood it at the time (as nearly as I can remember) this was simply the difficulty that if you quantized the harmonic oscillators of the field (say in a box) each oscillator has a ground state energy of (½)and there is an infinite number of modes in a box of every increasing frequency w, and therefore there is an infinite energy in the box. I now realize that that wasn’t a completely correct statement of the central problem; it can be removed simply by changing the zero from which energy is measured. At any rate, I believed that the difficulty arose somehow from a combination of the electron acting on itself and the infinite number of degrees of freedom of the field.

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参考文献：

https://www.nobelprize.org/prizes/physics/1965/feynman/lecture/