【按】犹豫半天还是决定在今晚看一下奥斯卡, 2006年的电影实在乏善可陈，但有一个看点让我有些兴趣---不知Al Gore这个傻冒能否拿个”小人头“回家。倘若一个政坛的失败者意外成为电影圈里的赢家，甚至可能拿下诺贝尔和平奖，那么这个Cinderella Story本身就可拍成电影，呵呵。在奥斯卡大戏开演之前，兄弟又重新开始阅读停顿在第192页的徐一鸿大作"Fearful Symmetry"。这回终于读到了最感兴趣的内容---Zee教授是如何在1972年与”渐近自由“这个可能是QFT最后一个大果子擦肩而过。读后觉得非常有意思，特在此分享几个段落。

在引文开始之前，谈一下对"freedom"这个概念的看法。Zee教授是这样解释的：

" ... a theory with zero coupling strength is said to be 'free' --- the particles in it would be free to move about independently of the other particles. A theory whose coupling strength moves towards zero as the theory is examined at ever higher energies is now called an 'asymptotically free' theory."

因此freedom和independence总是手拉手的两个概念，它们是密切相关的。这让我想起了Elton John的经典歌曲"The One" 中的那句"Like freedom feels when wild horses run"---

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http://www.ics.uci.edu/~jmadden/lyrics/the_one.html

This song has one of the most exquisitely worded expressions of the sensation associated with "that moment of dawning comprehension" that I have ever encountered. A sense of rightness, appropriateness --- a recognition and appreciation that it really is that simple. . . and of the reason for the simplicity.

There is no greater joy than to have such an epiphany when the revelation is of love and love returned.
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"Fearful Symmetry" by A. Zee, Chapter 12, "The Revenge of Art"

The Search for Freedom

...

And thus I embarked on a journey of the mind, looking at each theory in turn, in search of asymptotic freedom. It was quite a treasure hunt, made all the more exciting since I did not know beforehand whether there was any treasure to be found.

Unfortunately, none of the theories I looked at were asymptotically free. For example, the electromagnetic coupling increases as the relevant energy of the electromagnetic process increases. (It will turn out later that this fact is of crucial importance for a unified understanding of the universe.) I was rather disappointed.

In the fall of 1972, I joined the faculty of the Rockefeller University in New York. It was an exciting time for me personally: I was newly married, and my wife and I were released from Princeton into the big city, with all its attractions. It was also an extraordinary time in particle physics. ... One hardly knew whether to work on the strong or the electromagnetic and weak interactions, or, in my case, to sample the New York nightlife.

【点评】徐教授很有幽默感。Princeton虽然很像乡镇, 但却是安心研究学问的优良环境. 纽约这个大都市既有吸引力(attractions)，也有很多分心之事(distractions)。如果当年徐教授马上选择了Princeton给的教职Offer，那么”擦肩而过“也许就成了”正中下怀“。

I decided to do a little of each. Here I will tell the reader only of my search for freedom. Up to that point in my search, I had examined all the theories I had learned about in graduate school. But I had not examined this Yang-Mills theory, which everyone was talking about in connection with the electromagnetic and weak interactions, so I decided to do that next.

【点评】科学研究中的运气实在太重要了，尤其是在竞争激烈的领域。徐教授因为对Yang-Mills场不够熟悉，而需要时间去学习后才能开始用perturbation theory开始计算，可惜他在纽约而没有相关的合作者。此时他若还在哈佛的Sidney Coleman手下没有毕业，或者留在Princeton物理系任教而与David Gross合作，进入Yang-Mills场的计算就会很快。

In the winter of 1972-1973, I heard, as by thunder, the electrifying news that freedom was found. David Gross and his graduate student, Frank Wilczek, at Princeton University, and, independently, David Politzer, a graduate student of Sidney Coleman's at Harvard University, found that Yang-Mills theory is asymptotically free. The news was stunning --- we may finally have a handle on the strong interaction!

【点评】徐教授在回忆时很有风度，实在难得。我在为他扼腕叹息之余想起了杜牧名诗《赤壁》的后两句：

折戟沉沙铁未销，
自将磨洗认前朝。
东风不与周郎便，
铜雀春深锁二乔。

而赤壁战败的曹操在史学家心目中也当得起”虽败犹荣“这四个字，徐教授也就不必过于惋惜了，自是人生长恨水长东，呵呵。