再见幻想·科学类·十点五期·二零零六年十一月

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■ 访 INTERVIEW

郑大培 / Ta-Pei Cheng

　　我所热爱的是寻找自然界的高明之处（即为所谓物理美学）并尝试把事情组合起来。
这同样也是我喜欢写教科书的原因——收集不同的内容，以显示一个好的理论能把多少看
似不相干的部分组合在一起。我同样很喜欢教书。教书这件事情我做得比较好，是因为我
发现讲解明白是一件相当愉悦的事情，也因为我有能力与那些希望学习物理的青年学生心
领神会。

徐一鸿 / Tony A. Zee

　　当时我们家从香港移民巴西，我妈妈不知道我们到那边还会不会有学上，就买了很多
书带上，其中有一本物理书。在船上（当时坐船从上海到巴西要50天，不像现在的年轻人
做飞机一天就可以）我在读那本书，就对物理很感兴趣。

■ 说 POSTSCRIPT

　　这是《再见幻想》杂志蓄谋以久的科学类专访项目。我们希望做的，除了给所有向往
科学的青年人多点一盏灯，还想通过与那些生活相对更单纯的人对话，来探讨理想和生活
的意义。无论如何，学校的目的除了教授技术（科学可能永远也不能被成功“学习”），
还可以使得青年人不必过早陷入谋生困境，而这其中的后一点，是和每一个青年人息息相
关的。如果这个项目还能继续，它将被不定期地作为增刊编入《再见幻想》杂志中。整期
杂志为中文和英文，其中所有内容的中文版本被严格保证，而英文版本只在某些情况下出
现。作为《再见幻想》杂志的一贯特征，我们将尽量延续所有文本反版权的性质，以便最
大程度上保证它们被简易地传播。

　　本期杂志推出的是两位旅美华人理论物理学家的专访。访者的选择与整个项目最初倡
导者的专业兴趣有关，但另外的原因是理论物理永远是我们窥视整个科学的绝佳窗口。我
们尽量避免了过于专业的问题，以使得采访文本能够对尽量多看到它的青年人有益，但是
同样的，我们也尝试努力保持采访的科学普倾向。

　　再见幻想 | 在蜕变中湮灭出品
　　作为非专业访者的我们 | H.O.L.M + dk + 未来的你？
　　anti-© 创造共用协定 | 署名-非商业用途-保持一致 | 请在此框架内对其进行
传播

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■ 访 INTERVIEW

郑大培 / Ta-Pei Cheng

  What I enjoy most doing in theoretical physics is the pleasure of seeing h
ow beautifully the universe are put together the aesthetics of physics. This i
s also why I enjoy writing books collecting items to show how a good theory ca
n bring so many disparate parts together. As it turns out, I also enjoy teachi
ng very much. I do it reasonably well because I find explaining things well to
be a real pleasure and because I do have the ability to empathize with the st
udents who are trying to learn.

徐一鸿 / Tony A. Zee

  When my family immigrated from Hong Kong to Brazil, my mother did not know
whether we would be able to attend school there. So she bought many books, on
e of which talks about physics, to bring with us. I was reading that book on t
he ship (back to then, it took 50 days to sail from Hong Kong to Brazil, while
today's young people only spend one day on such distance), and became interes
ted in physics.

■ 说 POSTSCRIPT

  We have planned this Scientific Interview project for a long time. By this
project, we hope to give light to those young people who dream for science, a
s well as discuss the meaning of dreams and life, through conversations with p
eople living a relatively pure life. Anyway, schools are not only for teaching
skills (science might not possibly be learned successfully), but for saving y
oung people from struggling with making a living too early. The later is close
ly related to every young person. If we can continue this project, it will be
part of the magazine Goodbye Fantasy, with no planned timeframe. The overall m
agazine contains both Chinese and English contents, Chinese version warranted
but English version available only in certain circumstances. Following the con
vention of Goodbye Fantasy, we will try our best to keep all text copylefted,
so that they can be distributed as easily as possible.

  This issue contains interviews with two Chinese theoretical physicists in
the U.S. The selection of interviewees is based on the professional interest o
f the initiator of this project. However, another reason is that through theor
etical physics, we could always see the entire picture of science. For the pur
pose of comparison, we asked similar sets of questions. We avoided professiona
l questions as much as possible, to make these interviews beneficial to as man
y young people as possible. But at the same time, we also tried keep our inter
views science-oriented.

  Goodbye Fantasy | Produced by Annihilation in Decay
  We as unprofessional interviewer | H.O.L.M + dk + future you?
  anti-© Creative Commons Deed | Attribution-NonCommercial-ShareAlike


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郑大培 / Ta-Pei Cheng

　　郑大培先生是一位美籍华人粒子物理学家，他任教于坐落于圣路易斯的密苏里大学。
他是三本理论物理专业教材的（合）作者。采访者上个学期在北大修量子规范场论课程时
，曾经读过他（与卡内基-梅隆大学的李灵峄合著）的《基本粒子物理的规范理论》一书。
这次《再见幻想》杂志对他的采访，主要涉及一些与物理以及与社会有关的问题。

　　■ 你怎样看待“基本粒子标准模型”?

　　□ “标准模型”是现今粒子物理的标准理论。它描述物质基本元素夸克和轻子之间的
基本作用即强、弱和电磁相互作用。它是在量子场论特别是“规范场论”的基础上建立起
来的。换句话说，在所有可能的量子场理论中有一种极特殊的类别，它具有所谓“定域对
称性”。如果在某种确定的变换下物理定律（比如物理方程）不变，我们就说某种物理理
论具有某种对称性。比如说，“旋转对称性”的意思是物理方程在相差一个转动的不同坐
标系中写出是不变的。旋转对称性告诉我们，当你做物理实验时，面朝北或者西南是完全
无差别的。当忽略掉某个定域性质的特殊性时，我们会发现在这两个方向物理定律是完全
相同的。一种具有“定域对称性”（或称 “规范对称性”）的理论，即使在我们对每一个
时空点作出不同的变换后仍然是不变的。比如对于定域转动变换来说，我们可以让一个时
空点A绕z轴转30度，而让另外一个时空点B绕x轴转45度。换句话说，这种变换是对于特定
时空点的定域方程，这个方程对于不同点是完全不同的；而在这样奇特的复杂变换下，我
们的理论仍然可以保持不变。由于某种历史原因，这种定域对称性同样被叫做规范对称性
。对规范对称性理论的这种苛刻限制，我们并不必如此惊讶。事实上，当某种对称性被特
别指定时，夸克和轻子的荷即被指定，所有其它的一切均被确定了：特别是所有它们之间
可能的力也被完全确定了。就是通过这样的方法，物理学家得到了粒子之间相互作用的基
本理论，即所谓“标准模型”。

　　标准模型包括两个部分：一部分是温伯格、萨拉姆和格拉肖的弱相互作用和电磁相互
作用的统一理论；它引入一种被叫做“自发对称性破缺”的机制（也被叫做希格斯机制）
。另一部分是强相互作用的规范理论，我们把它叫做QCD（量子色动力学）。

　　那么我们为什么要称其为“标准模型”呢？“标准”在这里的含义是原型、范例或者
具有代表性的特征。因为在规范场论的框架下，我们仍可以考虑所有我们可以想到的对称
性群所导致的变换，而对于不同的变换，我们可以给夸克和轻子指定不同的荷。温伯格-萨
拉姆-格拉肖理论和QCD是可能描述分别作用力的最简单的变换。因而，史蒂芬·温伯格建
议把这个理论叫做标准模型——区别于所有其它同样可能的变换。规范理论中最简单的可
能性恰好（被物理实验所证明）是正确的理论。在过去的三十年中，它已经经历了上千次
物理实验的考验。因而，物质及其相互作用的基本理论仍然被“标准模型”这样一个简单
并朴素的名词所描述。

　　■ 什么是你（或者在你的眼光下的物理学家）对于“标准模型”的标准？我所说的标
准模型包括“基本粒子标准模型”、“宇宙学标准模型”或者所有我们中某些人称之为标
准模型的东西。比如说，我们大家大概都同意，现在尚不能把超弦理论称之为一种标准模
型。

　　□ 就像前面我曾经说过的，我们（物理学家）把“标准”理解为一种原型、范例或者
具有代表性的特征。换句话说，它是我们对于某种正教的一种更谦逊的说法。说这种说法
谦逊，是因为我们并不把其它相竞争的理论看作歪门邪说。但是，它确实暗示了这已经是
一种稳固的理论。当然，并没有某个“权威认证”说它确实无愧于这样的称呼。就像所有
的语言惯用法一样，它只是自然出现的。当有足够多的人认同这样一种表述时，它就作为
一种习惯用语被建立起来了。

　　比如说，在五六年以前，“宇宙学标准模型”的含义仅仅为在罗勃特森-沃尔克度规下
的膨胀宇宙模型。大爆炸的暴涨理论虽然在1980年代即被认证的讨论过，却仍然仅仅被作
为一种猜测。现今，通过对宇宙的加速膨胀（通过对遥远高红移超新星的观测）、微波背
景辐射各向异性以及星系的大尺度结构分布的研究， “宇宙学标准模型”所包含的不再仅
仅为罗勃特森-沃尔克度规下的膨胀宇宙表述，还有暴涨宇宙学所给出的大爆炸描述。在随
后的理论研究中，我们认同我们的宇宙具有平直的时空，物质/能量的组分包含暗能量（7
0%），暗物质（26%）和普通重子物质（少于4%）。我们这样说，是因为只有这样一幅图景
才能与观测数据相洽。对于在这个领域中的大多数人来说，相比于其它可能性，这幅图景
已经被提升为“标准”的。

　　你是对的，现今情况下并没有某种量子引力理论达到了这样的发展阶段。尽管超弦理
论（相比于诸如“圈量子引力理论”或者“扭结理论”一类的理论来说）相对来说是最成
熟的一个，现今我们中仍没有人敢叫它“大统一理论的标准模型”（即使某些该理论的倡
导者在心中相信这个理论是一种标准理论）。部分原因是目前尚没有使人信服的实验证据
显示超弦理论的正确性，也因为这个理论目前尚在发展中，其中的某些决定性的部分（比
如说某些潜原则）尚不被我们所知。

　　■ 作为一个物理学家，你怎样看待数学？

　　□ 自然界的语言是数学，这一点应该是一个深刻的真理。试图理解自然的过程的一个
重要部分，即为寻找其数学语言。比如说，当我们一旦意识到量子力学的恰当数学语言是
希尔伯特空间中的复矢量和算符时，所有其它的相关物理便自然显现出了：比如不确定性
关系、薛定谔方程等等。这种语言能够帮助我们更深刻地洞察自然界的内部，虽然初看起
来，我们也许觉得它颇为奇异，比如，纠缠态（EPR佯谬）也使得爱因斯坦感到困惑。

　　■ 从物理的角度，你怎样看待数学中的一些深刻定理（我的意思是诸如“哥德尔不完
全性定理”一类）？那么，你怎样看待物理真理和数学真理？

　　□ 物理真理在被多种多样的实验验证以前仅为暂时的，但是我总假设数学真理是更绝
对的，因为它仅存在于数学家建构的一个有限领域中。只要它的证明是自洽的，按照定义
他就是正确的。在这里我想先采用一个比较狭义的观点，即数学是一个人造结构的“游戏
”。我想很多数学家也许会强烈反对我这样的观点：她/他们会认为数学并不仅仅为一个人
造的游戏，而她/他们的工作确实是在“发现”数学真理。随着时间的流逝，我个人越来越
倾向于后面一种观点——当我发现宇宙的奥秘似乎是一个比物理真理大很多的集合时。是
的，我们确实可以发现一些数学真理，它们看似在物理世界一无所用。但是这些真理仍然
作为更广泛意义上的宇宙奥秘的一部分。我会继续牢记数学家所发现的那些真理。它们起
初看起来似乎完全和物理世界无关。但是一次又一次，物理学家发现这些信的数学语言，
正好能用来描述自然现象。四五十年以前我和我的同学都才意识到微积分和非欧几何于物
理相关时，那些被数学家所研究的更抽象的数学（比如说拓扑学、代数几何等等）被认为
是完全与 “真实”世界无关的——它们是完全无用途的玩具。但是在70年代和80年代初，
很多抽象数学分支被发现其实是和物理学紧密相关的。

　　■ 在你的观点下，探索物理真理时我们为什么要依赖数学？或者是否因为数学其实等
价于任何形式的逻辑？

　　□ 当然是这样！物理学的任务即为寻找描述我们的物理世界的最简单的可能描述。一
次又一次我们发现数学恰为那个可以给出简单描述的语言。不仅如此，数学由于作为一种
自然语言，允许我们仔细去研究这种表述的细节，以使我们对于这种表述的正确性树立信
心。我相信那些西方的重大发现（我指那些数学与物理描述相关的）是我们的文明在几百
年以前发生巨大跳跃的重要诱因。

　　■ 你怎样看待哲学？你认为哲学研究和物理研究能够帮助对方吗？

　　□ 哲学有很多的侧面。但是，让我们把讨论的问题仅仅局限于科学哲学特别是物理哲
学中。在这里我要说，哲学家所说的话从来不曾给我留下过深刻印象。在我涉足的领域中
，从没有一次她/他们说的话帮助我对这个领域有了更深刻的理解。有的时候，我觉得她/
他们就像科学的寄生虫一样。每当物理学家发现什么，她/他们就会说一些异想天开的话，
但是这些话从未给我们带来新的见解。本来，哲学家应该是那些抓住事物本质的人，但是
对于现代物理学来说，我觉得她/他们仅仅是在把事情搞迷糊。当然，在这里我要再次强调
我所谈的只是现代物理学所带来的哲学讨论。我的负面评论并不适用于其它哲学研究。


　　■ 从物理学家的视角，你怎样看待“自由意志”？

　　□ 对于“物理学家视角下的意识和自由意志”，我并没有什么独到的观点。有一些物
理学家，比如说魏格纳，认为物理学的新前沿即为自由意志：人们需要新的物理定律来理
解意识。这个问题通常会和量子力学的测量问题（观测者对于物理系统的影响，等等）一
起讨论。当然也有一些人认为我们已经有了解决一切生物问题的物理化学基础，这其中甚
至也包括意识。换句话说，靠着我们在神经科学上点点滴滴的进步，总有一天我们可以理
解意识，其仅仅为现今已知的物理和化学的直接后果。当然，即使我们并不需要本质上的
新物理，解开我们的大脑之迷仍然是一个重大的科学发现。

　　■ 作为一个关注现代物理的理论物理学家，在过去的若干年里，你是否还接触过牛顿
力学？从量子理论（或者其它类型的现代物理）的眼光下，你怎样看待牛顿力学？

　　□ 你的意思是否是说，如果我们知道这个世界的基本理论是量子力学，我们为何仍然
要学习牛顿力学？这将是我试图回答的。

　　首先，我们需要时常提醒自己“什么是物理学的真正目的？”我们的目的应该是寻求
对物理世界最简单的可能描述。我们要寻求的总是可以达到这个目的的最恰当的（或者说
最“正确”的）概念和数学语言。基于这样一种联系，让我们回忆一下牛顿（第二）定律
F = ma 的重要性。事实上，我们也可以把它仅仅看作一个定义式（力只是对质量乘以加
速度的一种简写）。如果它仅仅是一种定义式，为什么它如此重要呢？牛顿曾经教导我们
的是，如果你希望用更简单的方法描述这个世界，请特别注意质量乘以加速度的这个组合
。如果你这样做了，你会发现我们可以对于诸如苹果为什么从树上落下来，以及行星为什
么围绕太阳转这样一些问题获得更统一的描述。即使是现在我们知道量子力学比牛顿理学
更基本时，用量子力学描述宏观现象仍然是不恰当的。但是当我们进入原子尺度时，力的
概念便并不那么适用了，而能量（特别是拉格朗日形式和哈密顿形式）起到了更重要的形
式。此外，很多量子力学概念都是从牛顿力学中而来的：比如拉格朗日量、哈密顿量、最
小作用量原理等等。只有当我们对我们相对熟悉的宏观尺度上的抽象物理概念有了更深刻
的了解时，我们才能够有一些信心探索原子和亚原子尺度的物理，因为在这些时候，直觉
已经很少有机会帮助我们思考了。

　　■ 在你学习过量子场论这样的近现代理论物理课程之后，是否还时常回顾牛顿力学（
我发现即使对我来说，现在已经很难读一本有关牛顿力学的书了，即使我知道它远比我四
五年前学习它时所理解的要深刻的多）？你觉得，与一个不了解现代物理的人相比，你看
待牛顿力学时有什么不同的眼光？

　　□ 我认为牛顿力学和量子场论都是我们的物理知识中的一部分。但是，就像我在另一
个问题中曾经对你说的，尽管如此，原则上量子力学和量子场论都是建立在经典物理学之
下的。这并不意味着由于我们发现了量子力学就该轻视经典物理了。这就像我们说原子物
理是化学的基础，但却不能够由此停止研究化学一样。现在意识到这些联系是很重要的，
这让我们知道我们做的每一件事在我们整体的科学探索中处于怎样的位置。除此以外，我
相信我们还没有意识到量子和经典力学之间深刻联系的全部。当然，如果我们把普朗克常
数设为零便可以得到量子力学的经典极限。但是量子力学的有关测量的（比如波函数的塌
缩等等）疑惑却仍然萦绕我们。这个问题毫无疑问是与经典系统和量子系统之间的相互作
用有关的，但是它却还并未被我们所理解。

　　在某一个领域中了解更多高深的问题，当然会使得我们看这个领域更全面。我经常给
一年级的学生讲述物理学的入门课程。原则上任何一个物理学本科毕业的学生都可以做这
件事情。但是，我确实认为，我对于物理如何发生的了解，以及对该领域更宽阔的视野，
可以巧妙的给我的教学增加点什么。

　　很多科学家（很不幸其中很多都是粒子物理学家）相信她/他们所研究的是最重要的物
理分支，因为她/他们研究的是最根本的东西：她/他们发现的那些可以解释其它所有的一
切。我认为她 /他们的观点是错误的。当然，如果我们最终发现了粒子物理的大统一理论
（包括量子引力理论），那将是一个巨大的成就。但是，这一点真的能够更好的帮助我们
理解QED和原子物理吗？不能。能够更好的帮助我们理解化学和生物学吗？也不能。能够更
好的帮助我们理解意识和自由意志吗？同样不能。此外，这里还总有一种不恰当的傲慢—
—我们总认为重大思想是使得基础科学进步的原因。我质疑这一点。很多粒子物理学家在
和固体物理学家在一起的时候总感到一种优越感，她/他们觉得“归根到底，我们已经很清
楚凝聚态下面的物理是量子理学和电磁相互作用，我们要做的无非是重构一大对这样的粒
子组成的系统所造成的物理后果！”一个更理智的人会注意到，在引入新的固体物理理论
时，我们需要与引入粒子物理理论发挥一样的创造性。要知道，粒子物理中的一个非常重
要的概念即“自发对称性破缺”，它就是我们在研究超导时首先意识到的。

　　■ 你认为物理学家的思维方式和其她/他是否有什么不同（我的意思是，所谓“物理
学的思维方式”是否是一个存在的东西）？或者说物理学家和其它人只是在研究不同的东
西，却运用同样的方法？

　　□ 每一个领域都有其获得知识的特有方法。我相信存在“物理学家的思维方式”这种
东西。除了强调一些细小地方的定量计算，物理学区别于其它学科最重要的思维方式即为
在理解问题时直指它的精髓——通常还会建立能够描述这个问题最主要特征的简单模型。
虽然这种方法也可以被用于我们获得知识的其它分支，但是物理学家尤为擅长运用它。


　　■ 我们怎样判断在物理中什么是重要的而什么不重要？那么模型呢？

　　□ 物理学的一个重要部分即为，我们对理论的某些关键的物理特征和基本形态有更直
接的检测。当然，在我们判断谁是一个好的物理学家时一个标准就是好的物理学家是那种
有“特别直觉”知道哪些东西重要与否的人。重要的物理不但在我们可以直接接触的物理
情形中可以适用，而且在与这种情形相差甚远的地方仍可以作出推测。我一次又一次看到
，一个理论物理学家花费其全部精力进行一项艰苦的计算。现在我们知道，她/他的计算结
果是完全无意义的。但是一个好的物理学家可能仅仅做一些简单计算就可以勾勒出一整个
研究领域。你谈到了模型，我想以上的标准同样可以用来判断一个模型是好是坏。一个好
的模型是可以帮助我们在一个大领域中找到问题的核心和下一步的研究方向的。

　　■ 在我的定义中，“模型”就是那种我们忽略次要影响因素而保留主要因素的东西。
我们能不能/我们怎样能判断那些因素重要与否呢（我指在实验中和在模型中）？我们如何
来相信模型？

　　□ 我们必须要作出判断。大体上，重要因素就是那些在其它因素之下、并且它的效力
可以影响到大量其它物理现象的东西。哪些因素被物理界认为是重要的，这一点本身是一
个有趣的社会问题。从我的个人经历讲我认为，物理学家和其它任何人群一样，倾向于认
为某几个特定的人对于问题有更深的洞察力并且追随她/他们。如果这些领路人的看法最终
被信服，那么某种一致性就最终显现出来了。

　　■ 作为一个理论物理学家（我不知道这样的定义对你来说是否是恰当的），你怎样看
待实验和实验物理学家？

　　□ 简单地说，如果没有实验的话便没有科学。

　　■ 你是否能够帮助我解释一下我的悖论？如果理论物理学家告诉实验物理学家什么实
验是值得做的，而实验物理学家告诉理论物理学家哪个理论是对的或者错的（那些能够预
言实验的理论是我们的最爱），这意味着物理是某种强烈依赖于历史并且并不具有时间平
移不变性的东西。由此，我们还怎样能把物理叫做“真理”呢？

　　□ 一个人需要时刻提醒自己，科学是一种人类社会活动，并不是只向精英份子展示的
真理。就像所有其它的人类活动一样，科学的发展受到社会背景和历史的影响。记得即使
牛顿都曾经说过：我能看的更远是因为我站在前人的肩膀上。所谓的科学真理，如果你执
意要这样称呼它，是由一种特定的人类交往和人类创造而来的。对于我个人来说，恰为这
一点让我觉得科学是如此有趣。

　　■ 为什么你会决定学习物理？为什么你会决定做一个理论物理学家而不是一个实验物
理学家？

　　□ 我个人并没有那样“崇高的”故事：当1960年代我在读本科时，物理恰好很火——
很多好学生都被物理学所吸引。在美国，二战之后的物理学家具有极高的社会地位（她/他
们发明了原子弹！）。此外，由于苏联成功发射了人造卫星，美国政府非常恐慌——她/他
们害怕自己在科学和技术上落后于苏联。大量经费被投入物理研究。不过对于我们这些到
西方的中国学生来说，还有另外的两个原因。我们中很多人学习科学和工程学是因为这被
认为是最少依赖于一个学生的文化背景和语言能力的。另外一个原因是1957年李政道和杨
振宁获得了诺贝尔奖。对于我们这些海外中国人来说，他们是我们的英雄。我们中国人终
于有了一些值得骄傲的事情。我给你举一个例子吧：我在香港读高中时的英语老师来到教
室，眼泪汪汪地告诉我们有两个中国物理学家获得了诺贝尔奖。毫无疑问，这样的社会氛
围深深影响了我们。

　　下面我来谈一谈理论物理学家和实验物理学家的比较：这其中有很多层的原因。我是
一个在教室中成绩比较优秀的学生。就像我曾经提到过的，这理所当然地使我具备成为一
个理论物理学生的能力。而在另一方面，我知道我对付实验仪器时，并没有很好的才能。
不同于我有耐心接连几小时追逐演算过程中的一个负号，我却不愿意去固定一条实验中的
漏水管。不可否认，当时社会流行的“好学生应该去学习理论”的无形压力对我来说也是
另外一个影响。现在回顾来说，其实还有第三个原因。在1950和1960年代，整个物理学界
全部被粒子物理主导了。但是如果想做一个实验物理学家，就需要在一个大的队伍中工作
并且奔波于遥远的加速器实验室之间：这并不是我所喜欢的生活方式。

　　你大概会问另外一个问题：“你是否觉得你当时的决定是对的呢？”回顾来说：“这
对我来说是一个正确的决定。”虽然有时，我仍然会想作为一个理论物理学家，我是否对
物理学做出过贡献。对于一个实验物理学家来说，即使她/他并没有作出什么大的发现，对
于某些物理量的耐心测量仍永远是一个好的真实的贡献。但是从另一方面讲，一篇离题的
理论文章则完全是一无是处的。在我做了如此多年的理论工作之后，我对于我的处境有了
一些更清楚的认识。首先，我终于明白了为什么我热爱我所做的工作。大多数物理学家进
入这个领域是因为她/他们有热烈的好奇心，她/他们试图知道我们的世界是如何工作的。
对于这类人的一个典型，她/他可能在非常小的时候，就希望能把事情分解为简单的小部分
并研究清楚。我并不属于这样一类人。我所热爱的是寻找自然界的高明之处（即为所谓物
理美学）并尝试把事情组合起来。这同样也是我喜欢写教科书的原因——收集不同的内容
，以显示一个好的理论能把多少看似不相干的部分组合在一起。我同样很喜欢教书。教书
这件事情我做得比较好，是因为我发现讲解明白是一件相当愉悦的事情，也因为我有能力
与那些希望学习物理的青年学生心领神会。

　　我需要特别指出的一点是，实现人生价值有很多不同的价值。一个人并不一定要是“
天才”才能从事理论物理研究。

　　■ 你曾经说过你喜欢“收集不同的内容，以显示一个好的理论能把多少看似不相干的
部分组合在一起”。这是否仅仅是一种对秩序的偏好，或者这是我们的世界本应有的样子
？你怎样看待物理中的美学？

　　□ 我想这并不仅仅是一种偏好。这是我的工作和职业背后的驱动力。虽然我仅仅在物
理学中做一些间接的贡献，我很高兴我是人类认识大自然的过程中的一名小卒。这基于一
种信仰，那就是世界是可理解的。当然，并没有什么先验的原因说世界一定是有秩序的并
且可以理解的。但是过去的实验已经充分证实了这种信仰。值得注意的（我想更恰当的说
法是“令我们非常费解的”）是我们可以在草稿纸上做一些计算，而另一个人可以做一些
测量并发现实验结果理论计算充分的接近。

　　就像爱因斯坦曾经说过的那样，最不可理解的事情即为这个世界是可以理解的。所谓
物理世界可以被理解，这一点对我来说的含义是，它可以通过简单的方式被描述出来。这
样的一种描述（基于我们现有的物理理论）对我来说就是一种很美妙的事情。这即为物理
之美，也是那种让我如此振奋以至于一定要与别人分享的美学。

　　■ 除了喜欢“看我们的宇宙以如此巧妙的方式被组合起来”，你认为美学是否还在其
它地方影响你的生活？它是否在改变你的生活方式？或者它是否在改变你的人生观和世界
观？

　　□ 你是否在问我美学对我生活的其它侧面是否重要？我想是这样的。我很喜欢那些把
很多注意力放在生活美学上的文化。我要说所有伟大的文明，（基本上其实这一点本身就
作为伟大文明的定义）都有伟大的艺术成就。那么这是否改变我的世界观呢？从上面的回
答看，我想大概是吧。那么人生观呢？是的，我会相对来说更喜欢一个有艺术修养的人—
—但是希望我的判断并不受传统仅总是外观的审美影响。

　　■ 物理学对你生活的其它侧面是否重要？

　　□ 对于我个人来说，这个问题的答案为否；我实在很难找出生活中的其它事情与物理
学相似的地方。当然作为一个物理学家我们对于事情有批判性的思维方式，在我们处理生
活中的其它事情时这种思维方式便自然会被使用。但是我并不是说只有物理学家才有这样
的思维能力。我要说所有受过教育的人（我并不是指那些仅仅拿到文凭的人）都具有这样
的思维能力。

　　■ 你曾经觉得疲倦吗？你曾经觉得对你的研究很失望吗（如果曾经有过，那是因为什
么）？

　　□ 当然我曾经觉得疲倦过，我也曾经对我的工作感到很失望。这是很正常的事情。但
是，我想要强调我曾经涉及过的另一点，那就是做研究虽然很艰苦，但是它却不像一个年
轻学生所想的那么艰苦。就像我曾经指出的，当一个人全心投入的时候，问一个直接的并
且看似显然的问题是非常重要的——这就是所谓研究！

　　当你问这个问题时，我想你还尚没有“对你的幻想说再见”。我想你尚且认为科学家
都是超人，她/他们在寻求真理的时候从来不感到疲倦。不，事实的情况是科学家和所有的
普通人一样。当然的确有一些客观准则来（最终）判断一件事情是对是错。从大范围讲有
相对更好的办法来处理争论。但是物理学家是人，她/他们也会遭遇所有人都会遭遇的失败
（所以，也并不因此而轻看她/他们）。像其她/他人一样，她/他们同样会为声望和权力斗
争。当然相比来说，这个事业会相对“干净”一些。

　　■ 对于一个因为兴趣而跑去学习物理的年轻人，她/他怎样判断自己的兴趣是否能长
久呢？

　　□ 这是一个很难回答的问题，因为没有人可以预见未来。不过大体来说当一个人很小
的时候，她/他倾向于具有更多的热情并且她/他的感觉也更容易被欺骗。有一次一个年长
的物理学家对我说，“当你年轻的时候，世界好像在燃烧着：所有的东西都是有趣的并且
令人激动的。”这会激励一个人在某件事情上走的更深更远。当一个人长大一些的时候，
她/他会逐渐变成熟。不过这只是比较而言的说法。我们常说理论物理学家通常是在她/他
们年轻的时候做了她/他们最重要的工作，普遍来说，这一点是属实的。但是也有一些杰出
的物理学家到了60多岁还能做很杰出的工作，特别是如果她/他们的立足点很高的话。

　　是的，每个人必须诚实地面对自己的兴趣。这是一个一直困惑你的问题吗？这个兴趣
与你的其它兴趣相比怎样呢？我并不很担心有关未来的事情。我想我们宁可对自己说：“
无论我做什么，我都应该极力做到最好。我要保持开放的头脑，并且我很欢迎改变。”


　　■ 实验物理学家可能成为一个好的物理老师吗？

　　□ 在我曾经的回答中，我把“教学”定义得过于狭隘了（我仅仅指在教室中的教学）
。但是大多数的物理课堂是指理论物理课堂。从很表观的层面上讲，一个具有很强理论背
景的人很容易驾驭这样一个课堂。但是我个人即有一些很好的课堂教学老师，她/他们实际
上是实验物理学家。她/他们可以更有形地讲解一件事情（而不是躲在数学方程式的后面）
。但是我需要说大多数的高级课程，我指比如研究生的电动力学、量子力学和量子场论，
通常是由理论物理学家教授的。另一方面，一个实验物理学的研究生的大多数训练都是在
真实实验中完成。在那里，教授往往是手把手的。

　　说到这里，我来给你举一些历史上的例子吧。在1930到40年代的物理新纪元中，有两
位美国物理学家具有显著的地位，他们分别为奥本海默和拉比——前者是理论物理学家而
后者是实验物理学家。他们两个都是重要的物理老师。当然，费米（他为芝加哥大学建立
了很强的物理系）不但是一个重要的理论物理学家也是一个重要的实验物理学家。但是费
米的情形太特殊了，我们并不能把他作为现实的例子（在过去的50年里，再没有一个粒子
物理学家能在在理论和实验上都做得很优秀）。

　　简单的说，一个实验物理学家可以成为一个好的老师：我指在教室里（特别是上本科
生课程）以及在实验室中。

　　■ 你是否认为理论物理适合于任何一个有志向学习它的年轻人，无论她/他聪明与否
？

　　□ 这个问题的答案依赖于一个人期望她/他的物理研究水平达到怎样的程度。如果她
/他希望成为第一流的理论物理学家，她/他当然需要对这样一个抽象的学科具有特别的天
赋。但是如果你的意思是学习理论物理使得自己能够做一些物理教学工作或者一些相关的
实验研究，我认为几乎所有学生只要足够勤奋都可以胜任。需要特别注意的是，如果需要
学习诸如量子场论或者理论粒子物理这样的学科，一些物理方面的预备性课程以及数学是
必须的。我们不能过于急切地期望自己在短期内学好这样一个学科。比如说我和李教授的
那本关于规范场论的书，虽被很多人认为相当容易理解，但却仍是写给高级研究生用的。
如果一个本科生希望通过这本教材来学习场论，虽说这并没有错，她/他一定会觉得非常困
难。如果希望学习超对称或者超弦内容，这个问题会更加严重。她/他比如有一定的耐心因
为必须一步一步来，否则她/他一定会觉得很受挫折。

　　■ 你曾经对我说“即使在美国，通常我们仍然很少见到女性粒子物理学家”。你是否
曾经有过女性的物理学生？她们的学习成绩如何？你认为男性和女性学生有何不同（我指
诸如思维方式等等）？那么，你认为为什么相比男性，更少见女性学习物理（在中国以及
在西方世界）？

　　□ 我至今为止并没有一个女性的博士研究生。不过其实我也并没有很多男性的研究生
——因为我在一个小的研究机构，而棒的理论物理研究组往往是在大的大学中的。我们学
校主修物理和天文的本科生中，大约有三分之一是女性。女性学生和男性学生做得是一样
好的。我认为目前女性粒子物理学生很少，主要是由于一些社会原因造成的。很容易理解
，如果某个领域中的女性很少，一个女性会更不情愿进入这样一个领域。除了缺少可以模
仿的榜样之外，还因为我们在某个领域中学习，和那些与自己相似的人在一起是让人感到
愉快的——事实上我们学习中很重要的部分即为与自己相似的人讨论。当然原则上男性和
女性可以共同组成学习团体——然而事实上这一点真想实现还有其它一些困难。一旦有足
够多的女性粒子物理学家出现，便一定会有更多的女性进入这个领域。我相信在不久的将
来，这一点即会实现。

　　另一方面，我并不想对这个问题做一个过于简单的回答：因为社会的障碍是非常真实
存在的。对于所有需要努力才能涉及的领域来说，这一点都是真实的。我们的社会在对待
男性和女性时是相异的，并且生理上的差别也是不能回避的。不同于一个男性可以有其配
偶处理家务照顾孩子以支持他，一个女性教授则需要处理好事业和家务两者（这一点在西
方已经有些改善，我相信在中国也一样）。在一个人成长的年龄（我指大约20岁到30岁的
样子），女性在她人生的这个特殊阶段全心投入物理研究是非常困难的。所以这里有一个
绝对不能回避的障碍。当然，确实有一些人，她们找到了克服这些障碍的方法。从另一方
面讲，如果一个人的人生目标是在兼有另人满意的生活及对物理作出贡献，她/他仍然可能
筹划出一种比较平衡的生活。就像我曾经说的，做一个成功的物理学家并不意味着做一个
最顶尖的物理学家。

　　■ 怎样的科学氛围对于青年学生探索科学是最适合的（我相信如现代中国这样每一个
人都想过安逸幸福的生活，这样的氛围一定是不好的）？

　　□ 我并不能太明白你的这个问题的含义。我希望我猜对了你真正希望问的，并尝试由
此展开我的回答。广泛的讲，学习这样一门困难的科学，具有学习伙伴是最重要的。理想
的情况是存在一群具有相同兴趣的朋友，她/他们可以一起学习。在这样一个群体中，自由
交流和相互交流得以进行，没有人会害怕问“笨问题”，每个人都会受益。是否所有的“
好学生”都在这个群体中，这类问题其实是并不关键的。当然，如果你的学习伙伴比你懂
得更多，你将在和她/他的讨论中获益。但是即使她/他知道的比你少，讨论仍然是有意义
的。在给学习伙伴讲明白某个困难的主题的过程中，讲解者同样会受益菲浅。换句话说，
最好的学习方法就是教授。一个人还应该知道几乎每一个人学习科学（特别是物理学）时
都会觉得自己是愚笨的。事实上，这并非因为学习者比较笨，而是由于这些学科的特性所
决定。如果那个回答问题的人真的明白她/他所说的，答案通常是非常直接的即“显然”的
——这总是使得你（那个问问题的人）觉得自己很笨。由于科学是一种具有逻辑结构的系
统，所有正确的答案必然是“显然”的。当然，这并不应该作为阻止一个人问问题的理由
，而仅仅是科学本身的特性而已。

　　我并不知道你所说当今中国所有人都追求安逸幸福生活这句话的具体含义。从我所了
解的情况来说，事实恰好相反：每一个中国学校中的学生都过于努力了（我所忧虑的是她
/他们过于努力了而并没有给个人成长留任何时间）。坦率地讲，我并不对于每个人想追
求幸福生活而感到烦恼。这只是人之常情，它太普通了。我所担心的是，似乎学生们学习
一个学科并不因为她/他们真的渴望学习它，并不因为一种内在的好奇心，而因为学习一些
什么是她/他们的义务，只有这才能带给她/他们好的社会地位。这样的东西很少可以给她
/他们带来自我满足或者巨大成就。

　　■ 我所指“安逸幸福”的生活即为在你的回答最后所提及的，因为“好的社会地位”
显然是一种安逸幸福的生活。我从没有在西方国家学习过，但是我听说中国学生在西方大
学中成绩总是最好的，但我却从没有听说有谁（我只那些年龄只比我略大的人）在当今的
科学研究中做的最好。让我感到奇怪的，似乎老一代的物理学家中有很多中国人做得是相
当优秀的（而且似乎如果她/他们的童年时代是在中国大陆度过的，她/他们全都出现在19
49年以前）。所以我的问题是什么样的社会分为对于一个青年学生探索科学是恰当的，因
为毫无以为中国传统文化并不是答案的全部。

　　□ 首先，我不确定是否老一辈比现今体制下的中国大陆学生获得了更好的教育。依我
的观点，所有“重大”的科学发现，都牵涉到机遇。大多数重要的科学家比较老仅仅因为
，她/他们活了更长时间因而有更有机会取得成就。我仍然不认同你的判断，你说青年中国
科学家（比老一辈在同样的年龄时）所取得的成就不多。在今天的美国就有很多杰出的中
国青年科学家。当然，并没有诺贝尔奖得主，但是这正是我说的统计概率。我们同样需要
牢记的是，很多次诺贝尔奖都给了很久以前就完成的工作。请你注意最近葛罗斯、威尔切
克和波利彻所获得诺贝尔奖的是他们1973年的工作（这就是为什么我们常开玩笑说想要获
得诺贝尔奖的一大条件就是要足够长寿）。

　　目前，如果说中国人的学术成就并不如她/他们在学校教室里做的那么好，这大概有点
道理。这与我们的文化并不强调独立思考有很大关系。在中国，无论是年轻学生还是更年
长的成年人，都很少有去质问权威的生活态度！同样在教育体制上这两种文化也有很大不
同。美国学生即使在小学教育中，就花很多时间做有主见的工作，并且其中很多工作需要
团队协作。因而，在这里青年人很早就开始“做研究”了。

　　另一个很有趣的差别是，在这里（美国）我们过度强调培养一个人待人接物的能力（
我想这种强调甚至有些过分了）。但是科学和其它人类社会活动一样，独立思考的能力和
团队协作的能力对最后的成功都是非常重要的。在中国（也或者是所有亚洲国家）的教育
体制中，只有竞争的一面被强调了。比如在我看来，李政道和杨振宁最终反目，与这种处
理人际关系的能力，不是完全无关的。当然，同事之间关系破裂是很常见的，但是如此充
满怨气以及如此的公开争吵却是很少见的。

　　■ 你说在中国教育制度中，“竞争”被过度强调了。但是老子告诉我们要知止（“知
足不辱、知止不殆，可以长久”），可见竞争并不是中国传统文化的一部分，恰恰相反，
过度强调竞争的是希腊人（她/他们说奥林匹克精神）。那么你认为是什么时候我们开始过
度强调竞争的？

　　□ 本质上东方和西方所说的竞争在意义上是不同的。西方人的竞争倾向于不同个人之
间的直接对抗，但我却仍然认为中国文化强调竞争——虽然通常的形式是与自己竞争，或
者为了达到某个设定的期望值而竞争。我牢记的是考试在我们的传统文化中起了多么重要
的作用。每一个学生的目标都是在考试中取得好成绩、获得第一名、做状元。我们希望勤
奋的学习可以很快转化为功名利禄，刚不用说是权力了。这一点深深植根于我们的文化，
甚至在今天，我们还会惊愕为什么在学校里获得第一名的学生并没有在毕业之后的所有事
情上获得成功。我们很少看到一个学生被鼓励按自己的兴趣去学习——几乎从来没有人提
过“学习的乐趣”或者“阅读的乐趣”这等事情，也没有学生被鼓励为了过一个完整的人
生而获取知识。相反，青年人被教导要“吃苦”：如果你现在努力学习，以后就会得到功
名利禄，如此这般。

　　你提到老子主张生活中的被动顺从。除了这个以外，佛教还告诉我们“万事皆空”以
及唯一生活的可能道路就是断绝所有欲望。当然，我们确实有这样的传统。但是我要强调
的是，它们并非主流。亚洲文化是被儒家所说的“尽你所能使得你自己、你的家庭和你的
国家获得荣誉”的价值观所主导的。只有那些想跳出这种现世主流的人，才会去诉诸于道
教和佛教——这只是我们社会结构中的支流，而那种强调竞争的主流文化仍然在持续下去
。

　　■ 那么，你怎样定义“成功”（特别是一个物理学家或者科学家的成功）？

　　□ 你问我怎么定义成功？每一个人都要被给予其特有的天赋和社会机会。每一个人，
如果她/他能利用自己特有的潜在能力做一些对人类有用的事情，她/他都能被称为一个成
功的人。定义一个人成功与否的另一个重要因素是她/他自己的康乐，比如对我来说，这意
味着与自己的周围人之间有一种温暖融洽的关系。对于我们这些足够幸运以至于不用为基
本生存问题疲于奔命的人来说，我们应该做一些超出日常生活琐事的事情，并尝试做一些
对人类有用的事情。对于我来说，这见事情恰好为物理和教学工作。但是在我看来无论一
个人做什么，即无论她/他从事地质学还是物理学研究，无论她/他是科学家还是零售商，
无论她/他是大学教授还是手工艺人，这些都是完全不关键的。最重要的尽量把要做的事情
做好——在个人能力限度内做到最好。

　　你还问我对“成功的科学家”特别是“成功的物理学家”的定义。“成功的科学家”
就是那些对科学的进步作出有意义的贡献的人。这个答案当然其实只是语义上的赘述。我
们需要时刻提醒自己的是，知识的进步具有各种不同的形式。通常所说最毫无疑问的进步
是新的科学发现。但是每个人有不同的能力：也有的科学家的贡献在于，她/他的工作使我
们对前人已经发现的东西有了更深刻的认识，在于发现已知的事情之间的新联系。同样，
我们的贡献也可以是做一个好的老师、或者一个好的科学记者、或者一个好的管理者，等
等。所有这一切都对科学的进步意义重大。

　　我想，当你问我这个问题的时候，事实上你暗中希望我告诉你这样的年轻人：怎样成
为一个好的科学家？我能说的只有，最开始的时候你在这个还是那个领域，这一点其实是
不关键的。因为每个人都会具有不同的能力和不同的机遇，你总要允许自己去接触各种不
同的机会。之后，你选择那个你特别被吸引的领域——你的特别天赋或兴趣使你能在这个
领域走得更远（我指，怀着热情去研究它）。在这样的情形下，你更有可能把这件事情做
好。

　　青年学生涉足一个领域时通常担忧的一件事情是，她/他是否具有能力“做出发现”。
所有我们在教科书上读到的发现总显得那样“聪明”，步骤总显得那样“完备”，似乎并
没有什么新的发现留待我们去做了。事实上在大多数情况下，新发现仅仅是由深入该领域
的人跨出的普通的“下一步”而已。因此，最重要的事情是让自己涉足这个领域（就像我
们所说的亲自动手），然后一步一步来，以至于最终全身心投入。一旦到了这一步，新的
发现便会自然而然出现了。恐惧自己是否有做科学家的天赋这一点，常和学生与科学的接
触方式有关。通常情况下，学生并不会自然而然意识到，学校教室中所教授的科学与真实
的科学研究是颇为不同的。在教室中教授的是那些逻辑上很清楚的“打好包的科学”。因
为如果想把长达两三百年的科学研究成果在课堂中讲授清楚，唯一的办法就是做一些总结
，然后得出结果。由于这样的原因，一切都显得如此富含逻辑、如此显然。但是真正获得
的科学结果通常很难是这样的。在物理上这意味着，我们在课堂中学习的都是一种合成的
理论。这就是为什么大多数物理学生想做理论物理学家，因为她/他们看到的全都是那些获
得全胜的理论。

　　■ 你怎样看待领导（我指，诸如你我都必须接触到的一个大的科学项目的领导，以及
其它地方的领导）？你是否认为“领导才能”对于一个物理学家来说是重要的？

　　□ 领导无疑是很重要的，因为如果她/他的行为能影响很多的追随者，无论这件事是
好是坏，她/他都是很重要的。领导即那种具有可引导她/他人的个人特性的人。她/他也可
以是一个不合群的人；人们跟随她/他完全是由于她/他的研究质量，或者她/他优秀的预见
能力。在对领导的一个如此宽泛的定义下，我想已经没有其它任何东西可以讨论了。但是
我想你其实问的是那些组织她/他人并安排工作的领导。当然，一个大的科学项目要想运转
，一小批人来指出大方向并做一定的行政管理是必须的。我相信这样的领导工作是很重要
的。大多数情况下，学校圈子里的人倾向于评价领导，并且很多时候领导除了为自身某福
利，并没有什么其它实质性的贡献，这一点也是事实。但是我想她/他们其实错了。一次又
一次我看到勤勉的领导者，她/他们努力做好自己的本职工作，并且她/他们的工作确实似
的那个团体里的人获得实质性的益处。通常，领导对于这样一些困难任务的完成是必须的
。如此领导才能在一个社会中应该被得到很高评价。

　　事实上我要说的是，在中国（或者整个亚洲）的传统教育中，在年轻人中培养这样的
领导才能并没有被足够重视。在这里我说的是广泛的教育而不指狭义的科学教育。在美国
孩子很小的时候，我们就要她/他们参与集体活动。当然，你一定要让她/他们参与她/他们
自己感兴趣的活动。最常见的活动是团队体育运动，这是很好的让小孩子互相建立友情、
协作并且培养她/他们的领导才能的方式。领导和领导才能在任何一个社会层面上都是重要
的。在这里，我说的并不指那种独裁者，她 /他们在没有做任何高明的劝导之前就把自己
的想法冠冕堂皇地强加给别人。而我们的文化通常并不强调培养处于某一个社会特有位置
所需要的领导才能，而过渡强调并冀希望于“伟大的领导”或者“伟大的救世主”，并以
为她/他能把我们带入天堂（实际上这完全等同于偷偷希望一个“贤明君主”的出现）。我
们需要反复向自己强调领导终究也是人；如果过多的权力过长时间集中在一个人身上，很
多负面效果便会出现。这件事情在政治上是当然的，不过其实在其它社会活动中也一样。
每一个团体都必须有自然的方式让领导更新换代。

　　■ 你怎样看待一个作为人的领导，和一个作为规则的领导？那么从一个我们无法违抗
它的角度理解，你怎样看待一种物理规则（定律）呢？

　　□ 我想你的问题是问一个人对于已经建立起来的正教持怎样的观点：无论是一种认识
论主题或者一个拥有权力的人掌控这种正教观点。在这里我要说科学界是一个相当保守的
群体。我的意思是，我们从不会轻易放弃一个已经被完整建立起来（一个正教的？）的理
论系统。一个复杂的科学理论要想被建立起来，它通常需要通过很多（有时候成千上万的
）实验和观测检验。如果什么新的现象被发现了，一个人总会倾向于认为原来的理论仍然
是对的。首先，我们需要确认信的观测是真是的（我就曾经多次使用过错误的实验结果）
然后我们还会尝试在旧的理论框架内理解新实验——去看那些看似矛盾的实验结果其实是
相互兼容的，因为已经建立起的理论框架或许有我们仍然没有发现的包括新现象的丰富内
涵。从这一点来说，粒子物理的标准模型是一个很好的例子。量子场论是人类理解粒子之
间相互作用的第一个理论框架。但是量子场论会造成一个无穷大。在长时间的辛苦探索之
后人们才意识到，如果那些计算被正确地作出（通过重整化步骤）那些无穷大便自然消失
了。接下来弱相互作用的研究中所遇到的那些无穷大却似乎不是已有的重整化步骤可以消
除的；人们最终明白了量子场论框架中可以允许“自发对称性破缺相”（希格斯机制），
这种机制给出有质量的中间玻色子，而这样的理论是可重整的。在对强相互作用领域的研
究中，我们意外发现了渐进自由、色禁闭等等一类丰富的物理内涵，这最终成功导致我们
建立起了QCD理论。所以最终量子场论仍然是一个正确的理论框架，虽然在其发展过程中，
很多人都曾经倡导放弃它作为高能物理的理论框架的地位。你当然可以反抗正教，但是这
通常不是一个人遇到新困难的时候的时候最初想做的。当然，量子力学是一场革命。但是
它也是在我们很多年尝试在经典理论的框架内解释新的辐射和原子物理问题之后才建立的
。这个根本的变革是被一批年轻学生（海森堡、狄拉克和泡利在那个年代都只有20岁出头
）完成的，他们的头脑尚且还没有被旧的物理学所约束，他们可以用不同的眼光看待这个
世界以至于最终发明了量子力学。薛定谔最初写出他的量子力学基本方程是他30岁的时候
；这个量子革命的“老人”最终却没有接受新的量子力学。

　　我并不是说一个人不能够反抗物理定律。但是这些定律是在非常牢固的基础上被建立
起来的，如果我们希望一个全新理论不但可以解决新遇到的困难还可以并不触碰老理论成
功解释的事情的话，建立这样的新理论并推翻老理论通常是很困难的。这就是为什么在物
理学的发展史中我们很少听说一个旧理论完全被一个新理论取代的原因。通常我们只会建
立一个更全面的理论：它不但包含新内容也包含旧理论。

　　■ 如果我们把物理理论类比为一般的领导，物理真理（我指那些类似于终极真理的东
西——即使我们永远也不能认知它们，并不是指我们现有的理论）即为那种永远正确的“
伟大领导”。那么，你怎样看待物理真理呢？

　　□ 把物理定律看作领导？！这是一个有趣的类比——我从来没有想过这个问题，但是
我会试一试。这种领导并不是被某些人任命的，它们通过很多艰苦的实验测试最终获得自
己的领导权。最终，所以人意识到并且心甘情愿地接受它们的领导权。但是，这种领导权
是不能变通的并需要始终被遵守的。这个理论也会发生革命。当然，我很高兴在这里我们
仅仅是在玩一个文字游戏。我并不想被这样一个领导所管制。在我看来，一个英明的领导
是易变通的并且在她/他制定社会规则时会考虑人之常情。我确定我不想生活在一个具有僵
硬专制的社会中。

　　■ 这是否意味着你并不相信终极理论？

　　□ 如果你的意思是说物理学的终极理论，我确实相信它——关于这个称呼的资格我在
前面的回答中已经讨论过：当新的实验现象出现时，物理理论总会有相应改变。我们必须
时刻牢记在曾经的一个年代，人们错误的认为物理学的终结已经触手可及了。并且，一个
“涵盖一切的理论”虽然给出了物理学各个分支之间的全局联系，却不能解释我们碰到的
大多数物理问题。

　　如果你的意思是说那种类比于领导的终极理论，我确实不相信有这种东西。

　　■ 你上次来中国是什么时候（我分别指中国大陆和台湾，如果你确实曾经去过的话）
？它给你留下了怎样的印象？

　　□ 我出生在上海，并且在那里截至我初中毕业。1956年，“百花齐放”时，我的姐姐
和我终于获得出境证来到香港与父母团聚。我在香港完成了我的高中学业，并于1960年到
了美国。我太太来自台湾，所以我们几乎每年都会回香港和台湾。所以相对来说，对于这
两个地方我知道的多些。我第一次回到中国大陆是1979 年底，那个时候中科院在从化（离
广州不远）举行一次物理会议。这次机会使我到了北京、广州和上海。在那之后，我只有
两三次很短促的访问——并不是因为某种官方的原因。去年我的家人和我在北京、西安和
上海进行了一次旅行。在这次旅行中，我访问了北京大学和中科院的两个研究所。事实上
，当时的一些安排使我有机会在北京大学教书一年。但是最终，我还是由于一些个人原因
拒绝了这个非常令人高兴的邀请，因为我不能离开圣路易斯很久。我对这些地方的印象如
何？当然，我对中国这些年发生的巨大变化感到震惊。无论是从新闻报道，还是从那些到
中国旅行或者短期居住的朋友那里，我都听说了这样的变化。我同样有一个来自中国大陆
的博士研究生。当我真正看到这些实质的变化时，我确实深感震惊。让我感到震惊的还有
，虽然最顶层的人（比如中科院的那些科学家）看起来高兴乐观，那些与我们在街边擦身
而过的陌生人却显得非常忧虑。除了其它事情，她/他们中的太多人在担心自己的孩子能够
进一个体面的大学。如果不能够，她/他们孩子的前途便会很黯淡了。我们整个教育制度中
存在一个大的等级，一个好的“品牌”对我们大家都太重要了。我相信这个问题在中国大
陆更加突出。但是实际上，在所有有华人居住的地方，这个问题都或多或少有所体现：在
台湾、在香港、在新加坡、或者在美国的所有华人社区。不知为什么，我们的传统文化过
于强调等级结构了。所有的事情都要被分等级，即使那些等级本身是没有意义的。人们甚
至不能够靠自己的判断来评价一件事情，而她/他们对那些“品牌”的东西所暗示的等级过
于相信。在台湾或者在中国大陆，利用这种缺点，各个品种的书都想办法在书名中加入“
哈佛”这个词：这便可以单薄它们被各种类型的没脑浆的读者阅读了。所以在台湾、中国
大陆和所有美国的华人社区中，人们疯狂的竞争试图到那些也许能在她/他们孩子身上发挥
奇迹般魔力的东西。由此很多东西都成了牺牲品——这其实是浪费精力和才能！但是这一
点却深深植根于我们的文化。大概需要很多年，一个由具有独立思考和判断力人群组成的
新文化才能被逐渐建立。我希望这有一天会发生。

　　■ 你觉得是否有一些问题我们并没有涉及，但是事实上是很重要的？

　　□ 你问了很多深入的问题，对我冗长落到的回答也很有耐心。请容许我最后再做几项
结语。

　　我希望每一个学生都能了解，不管她/他在大学里学了多少，那是绝对不足的——尤其
是在现今科学技术快速更迭的时代。所以在学校里最应该学习的，是如何在毕业后仍然能
够继续不断学习的能力。我指的是终身学习的态度，也就是用批判的眼光持久地阅读，不
管阅读是通过书籍、杂志、网页还是其它途径。没有人能预知未来，但是我们可以确知的
是，变化必是我们未来生活里的常数。对这持续变化的世界的最好准备，就是不断自我学
习的习惯。

　　课堂学习的不足，还可以表现在另一个层面上。在这次的对谈里，我们谈到的物理及
科学，都是在传统教学的格局里，也就是你听课、做习题、考试等等。对我来说，危险在
于，一个人学到了所有技术方面的知识，却没有吸收到更重要的“科学精神”。我所谓的
“科学精神”，是指宽阔的眼光、依根据做判断、以及永远用批判的态度面对来自周遭的
意见。我提出这一点，主要由于亚洲的教育系统一般而论，都过早地强迫学生决定专业（
最晚也是在大学刚开始的时候）。这种制度的危险在于它可能制造出一大群只有一面而度
的专才，她/他们虽然对专业机能的细节了如指掌，对于处理本行的事物也能驾轻就熟，但
当面对重大的决定时，她/他们却完全没有如何做判断的能力。我认为对此的解决方法，在
于减轻对考试的重视，并将对专业的决定，延后到大学的最后两年。这不仅给学生一个接
触不同学科的机会，以发觉自己真正的兴趣，同时也能给她/他们一个比较广泛与充实的人
文教育。这样的改制当然会被多数的大学排斥，因为现有的制度使她/他们对学生的流动较
有掌控。对于新制度，她/他们必会抱怨：“那我们怎么知道收进来的学生，到底会是去哪
个系？”但是如果有足够的人要求着这样的改革，这仍有发生的可能。

　　最后，我想对你和你们的杂志说几句称赞的话。你们在网上张贴的访谈录，在我所阅
读过有关中国教育系统的文字中，是最具有启发意义的。你和其她/他年轻人所从事的（民
间组织）活动令我十分敬佩。我深知国内的处境并不容易，但是你们的事业必会产生影响
，为此，我充满了希望。

　　2006年7月26至2006年8月31日，H.O.L.M网络采访/翻译。由于翻译水平有限，有能力
的读者请直接阅读英文原文，译者并不对翻译的正确性和准确性负责。被访者的太太苏友
贞女士对于翻译工作有极大贡献，事实上，她指出了我的很多处误译并帮助我做了一些翻
译。我的朋友dk在这篇采访公开前阅读过我的草稿并且给了我很多建议，她对问题的设置
亦有帮助。这个采访的文本遵守创造共用协定（署名-非商业用途-保持一致），你可以在
此框架内对其进行传播。

－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－

Ta-Pei Cheng / 郑大培

  Ta-Pei Cheng is a Chinese American particle physicist teaching at the Univ
ersity of Missouri, in the city of St Louis. He is the co/author of three theo
retical physics textbooks. The interviewer used to read his book Gauge theory
of elementary particle physics (with Professor Ling-Fong Li of Carnegie Mellon
University) when she studied gauge field theory last semester in Peking Unive
rsity. Today, Goodbye Fantasy interviewed him, and asked him something about p
hysics and society.

  ■ What do you think about the "Standard Model of Particle Physics"?

  □ "The Standard Model" is the fundamental theory of particle physics. It
describes the basic interactions of strong, weak, and electromagnetic forces a
mong matter which has the most basic elements being quarks and leptons. It is
formulated in the context of quantum field theory in general and "gauge field
theory" in particular. Namely, among all the possible quantum field theories,
there is a special class of theories having the property of being "locally sym
metric". A physics theory is said to possess a symmetry if under some definite
change (called a transformation) the laws of physics (namely, physics equatio
ns) are unchanged. For example, by "rotational symmetry", we mean that physics
equations are unchanged when written in different coordinate systems that are
related to each other by rotations. Rotation symmetry says that it does not m
atter whether you do an experiment facing north or facing southwest. After dis
counting any peculiar local conditions, we should discover the same physics la
ws in both directions. To have a "local symmetry", also called "gauge symmetry
", a theory is unchanged even if independent changes are made at every space a
nd time points. For example a local rotational change can mean that at one spa
cetime point A you can rotate the coordinate by 30 degrees around the z-axis,
while at point B, we change the coordinates by 45 degree around the x-axis. Na
mely, the amount of change is a local function of space and time (meaning diff
erent from point to point); yet the theory still remains the same under such f
antastically complicated changes. For historical reasons, such local symmetry
is also called gauge symmetry. Not surprisingly gauge symmetric theories have
very restrictive structure. In fact once the symmetry is specified, and quark-
lepton charges are given, everything else is fixed: in particular what possibl
e force acting between them follows inevitably. In this way physicists came up
with the fundamental theory of particle interactions, called "the Standard Mo
del".

  The Standard model is composed two parts: (1) Weinberg, Salam and Glashow
theory for the weak and electromagnetic interactions; it involves the mechanis
m called"spontaneous symmetry breaking"(also called the Higgs mechanism). (2)
The gauge theory of strong interaction, called QCD (quantum chromodynamics).


  Why the name of "the Standard Model"? The word "standard" here means the p
rototype, the exemplar, or the representative type. Because within the framewo
rk of gauge field theory, one can still consider all sorts variations dependin
g the symmetry group one can pick, and on the different charges one can assign
for the quarks and leptons. The Weinberg-Salam-Glashow and QCD were among the
first and simplest version that is capable to describe the respective interac
tions. Hence, Steve Weinberg suggested that we call this the Standard Model --
- against which all other variations were to be compared with. This simplest v
ersion of the gauge theory turned out (as shown by experimental tests) to be t
he correct one. It had successfully passed thousands of experimental tests tha
t had been performed in the last thirty years. This fundamental theory of matt
er and interaction has remained to be called by this simple and modest name, T
he Standard Model.

  ■ What is your (or in your opinion the physicists') standard of "Standard
Model"? I mean, maybe "the Standard Model of Particle Physics", "the Standard
Model of Cosmology", and the standard model of everything someone of us call
it a standard model. For example, we may all agree that we cannot call Superst
ring Theory a standard Model nowadays.

  □ As I said in my last message, by "standard" we (physicists) meant "the
prototype", "the exemplar", or "the representative type". In other words, it's
just a polite way saying it is "the orthodox". It's polite because it does no
t want to say that other competing theories are heretics. But it does imply th
at this is an established system. Of course there is not a "high commission" s
omewhere that officially sanctifies such names. Like any language usage, it co
mes out naturally. When enough people agree with such expression it becomes th
e established practice.

  For example, only 5 or 6 years ago, by "the standard model of cosmology",
people only mean the cosmology of expanding universe based on Robertson-Walker
geometry. Inflationary theory of the big bang is still considered a speculati
ve description even though it has been intensively studied since 1980. Now wit
h the discovery of accelerating universe (using the high-redshift supernovae),
and the new observational results of the cosmic radiation anisotropy, as well
as the large surveys of galaxy distribution, this expression of "the standard
model of cosmology" has come to mean not only the expanding universe based on
Robertson-Walker geometry but also a big bang as described by inflationary th
eory. This epoch was then followed by a universe having a flat spacetime, with
matter/energy content dominated by dark energy (70%), dark matter (26%) and w
ith ordinary (baryonic) matter being no more than 4%. This is so because only
such a picture can be concordant with all the observational data. To most peop
le in this field, this picture has now gained the statue of being regarded as
the "standard", against which all other possibilities are to be measured.

  You are quite right no theory of quantum gravity has reached this stage of
development. Even though the superstring theory is the most mature one (compa
red, say, to "loop quantum gravity", or "twister theory", etc.), no one dares
to call it "the standard model of unification" yet. (No matter how some propon
ents believe in their hearts their theory is the standard theory.) Partly it's
because there is no convincing experimental evidence for superstring, partly
because the theory is still a work-in-progress, with crucial parts (such as it
s underlying principle) still misssing.

  ■ As a physicist, what do you think about mathematics?

  □ This is a profound truth that Nature's language is mathematics. A good
part of seeking a comprehension of Nature is to find its mathematical language
. For example, once we learnt that the proper mathematics for quantum mechanic
s is the complex vectors and operators in the Hilbert space, then all sorts of
connections tumble out: uncertainty relations, Schrodinger equation, etc. Thi
s language would lead us to many insights of Nature which at the first glance
seem rather strange, such as the entangled states (EPR paradox) that so mystif
ied Einstein.

  ■ What do you think about some profound theorem (I mean, for example, God
el's Incompleteness Theorems) in physics? And then, what do you think about th
e truth in physics and the truth in mathematics?

  □ While physics truth must always be tentative until checked by multiple
lays of experimentation, I suppose mathematical truth is more absolute because
it is a truth about a limited realm having been constructed by mathematicians
. As long as the proof is self-consistent, it is by definition true. Here I am
adopting a more limited viewpoint of mathematics as an artificially construct
ed "game". But many mathematicians would strongly disagree with this viewpoint
DISCOVER the mathematical truth. As times go by I become more inclined toward
s this second viewpoint -- with the realization that the truth in this univers
e stands for a larger set than the physical truth. Yes, one can discover mathe
matical truth that is not realized in the physical world. But such knowledge c
onstitutes parts of a greater truth about our universe. I am continually impre
ssed by the truth that mathematician can discover. They may discover something
at first sight being totally disconnected to the physical world. Yet over and
over again, physicists come to find that these new languages are just the one
s they need to describe Nature. Forty and fifty years ago when I and my fellow
students all said to ourselves that while the mathematics of calculus or even
non-Euclidean geometry had relevance for physics, the abstract math (of topol
ogy, algebraic geometry, etc) that the mathematicians were studying then was t
otally divorced from "reality" -- a totally useless games. But starting in the
70's and 80's, many branches of abstract mathematics were found to be connect
ed to physics again.

  ■ In your viewpoint, why we need mathematics in the search of physics? Or
it is isomorphic with all kind of logic?

  □ Absolutely! The task of physics is to find the simplest possible descri
ption of our physical universe. Again and again we have found that mathematics
is the language that can provide this simple description. Furthermore, mathem
atics as Nature's language allowed us to check such a description in detail, t
o give us confidence as to the correctness of this description. I believe that
the West's great discovery (of the relevance of math for physical description
) was a very important element that had brought the great-leap-forward of our
civilization a few hundred years ago.

  ■ What do you think about philosophy? Do you think philosophical study an
d physical study can help each other?

  □ There are many aspects in philosophy. But let's restrict ourselves to p
hilosophy of science, especially physics. Here I must say that I have not been
very impressed by what professional philosophers have to say. I have not come
across anything they have said that I felt it helped me to reach a deeper und
erstanding in this area. Sometimes I even feel that they were almost like para
sites. From what physicists have discovered, they just add many fancy talks wi
thout bring out any new insight. In fact philosophers are supposed to be the p
eople to bring out the essence of a subject. But in the case of modern physics
they only confuse things for me. Here again I want to emphasize that I am spe
aking of the philosophical discussion of modern physics. My negative comments
do not apply to other philosophical studies.

  ■ Do you like to say something about "freewill" in the viewpoint of a phy
sicist?

  □ I have no particular insight with respect to "a physicist's viewpoint o
f conscienceness and freewill". There are physicists, such a Eugene Wigner, th
ought that this is new frontier for physics: one will need new laws of physics
to understand conscienceness. These questions are often discussed in connecti
on with the deep mystery of QM measurement -- the effect of observers on physi
cal systems, etc. Then there are many people believe that we already have the
physical and chemical basis to understand all biological systems, including th
e conscienceness as well. Namely, bit by bit as we make progress in neuroscien
ce, we will one day understand conscienceness as consequences of the physics a
nd chemistry that we already have today. Of course, even we do not need fundam
entally new physics, to unravel the workings of our brain will take great scie
ntific discoveries.

  ■ As a theorist of modern physics, do you ever touch Newtonian Mechanics
for the past few years? What do you think about it in the viewpoint of quantum
theory (or some kind of modern physics)?

  □ Are you saying that knowing that the fundamental theory of the world is
quantum mechanical, why do we still need to study Newtonian mechanics? This i
s question that I will try to answer.

  First of all, let's remind ourselves "what is the goal of physics?" Our ai
m is to find the simplest possible description of the physical world. We try t
o find the most appropriate (the "correct") concepts and mathematical language
to accomplish this. In this connection, let's recall the importance of Newton
's (2nd) law F = ma. In fact one can view it as a mere definition (force is ju
st the shorthand for mass times acceleration). If it's a mere definition, why
is it so important? Newton was teaching us: if you want to have a simple descr
iption of the physical world, please pay particular attention to this combinat
ion of mass times acceleration; if you do so, you will find a more unified des
cription of why an apply falls from a tree; why the planets go around the sun,
etc. Thus even we know that quantum mechanics underlies Newtonian mechanics,
it will be totally inappropriate to describe the macroscopic phenomena using t
he QM language. In the same way, once into the atomic world the concept of for
ce is not so useful anymore, now it is energy (especially in the forms of Hami
ltonian and Lagrangian) that plays a dominant role. Furthermore, so much of th
e QM concepts are developed through Newtonian mechanics: Lagrangian, Hamiltoni
an, and the Principle of Least Action, etc. Only when one has developed certai
n understanding of these abstract concepts in the more familiar macroscopic wo
rld, can we use them with some confidence in the atomic and subatomic regimes,
for which we have very little intuition.

  ■ Do you ever review Newtonian Mechanics when you have studied Quantum Fi
eld Theory (I find even for me now, it's hard to read books about Newtonian Me
chanics, although I know it's more profound than I know from my study about 4-
5 year ago)? Compare to a person who do not know modern particle physics, do y
ou have some different viewpoint for it?

  □ I view Newtonian mechanics and QFT all as parts of our phyiscs knowledg
e. But, as I said in another answer, even though in principle QFT and QM under
ly classicsal physics. It does not mean we value classical physics any less be
cause of the discovery of QM. Just as we say atomic physics underlies chemistr
y. But it does not mean we can stop study chemistry. Now it is sometime helpfu
l to know this connection; to know where everything sits in the global scheme
of things. Besides, I believe that we have not heard the last word of the conn
ection between quantum and classical mechanics yet. Sure, one sets the Planck'
s constant to zero one gets the classical limit. But one area of QM that is st
ill of great mystery is the QM measurement theory (the "collapse of wave funct
ion", etc.) They are all related to the interaction between quantum and classi
cal systems, that's not well understood.

  Now knowing more advanced topics does lead to a bette all-round understand
ing of the field. I often teach introductory physics to first year students. I
n principle any physics college graduate can do just as well. But I do think m
y knowledge of how physics is done, and having a broader picture of the field,
in a subtle ways adds something extra to what I teach.

  There are scientists, unfortunately many in the particle physics field, be
lieve that theirs is the MOST IMPORT BRANCH of physics because they study the
most basic: what they discover will EXPLAIN EVERYTHING ELSE. I am of the opini
on that they are misguided. Yes, if we ever find their Holy Grail -- the unifi
ed theoy of particle physics (including quantum gravity), it will be a very im
portant acheivement. But will it help us undertand QED and atomic physics any
better? No. Will they lead to new insight in chemistry and biology? No. Will i
t help us understand conscienceness and free will? No. Furthermore, there is o
ften a misplaced arrogance -- somehow it takes greater minds to make progress
in these fundamental sciences. I doubted. A lot particle physicists felt a kin
d superiority to solid state physicists because "after all in condense matter
one already knows that what underlies their physics is QM and electromagnetic
interaction, all one needs to do is to deduce the consequences for systems wit
h large number of particles!" A more thoughtful person would observe that it t
akes just as much creativity to invent new solid state theory as any particle
physics theory. After all the one big idea in particle physics was "spontaneou
s symmetry breaking", which was first thought up by physicists studying superc
onductivity.

  ■ Do you think the physicists have some special thinking style different
from other people (I mean, do something like "Physical Thinking Style" exist)?
Or physicists just concerned different things from other kind of scientist, b
ut using the same method?

  □ Every field has some approach to knowledge that is characteristic of th
e field. I believe there is such a thing as "physicist way of thinking". Besid
es the emphasis on detailed quantitative approach, the most identifying featur
e of physicist-way-of-thinking is the tradition of reaching an understanding o
f the problem by reducing it to its essence -- often involving the constructio
n of a simple model that can bring out the most important features of the prob
lem. This approach can be used in many other branches of knowledge, but physic
ists are particularly good at doing this.

  ■ How can we judge what is important and what is unimportant in physics?
How about MODELs?

  □ An important piece of physics would have more direct bearing on some ke
y physical feature or some basic aspect of a theory. Yes, what distinguishes a
good physicist from a not so good one is precisely that a good one has that "
extra sense" knowing what's important and what's not. Important physics would
have all kinds of implications for situations far beyond the situation being a
ddressed directly at the moment. I have seen it over and over again that an or
dinary theoretical physicist who would spend a major effort doing a very diffi
cult calculation. Yet the result obtained is of no interested to others, while
a good physicist may only perform a simple calculation that illuminates a who
le area of research. As you bring up the subject of models, it is also true th
at there are good and there are not so good models. A good one can shine light
on a wide area and brings us to the heart of the matter.

  ■ In my definition, MODEL is something we omit secondary influence elemen
ts but maintain the important ones. Then, can we / how can we judge whether a
element is important or not (in an experiment and in are model)? How can we be
lieve models?

  □ This is a judgment people have to make. By and large, an important elem
ent is the one that underlies many other matters, and its validity would have
a larger impact on other physics phenomena. How certain elements come to be re
garded important by the physics community is an interesting sociological thing
. I notice from my experience that physicists, like any group of people, have
a tendency of recognizing certain persons as having deeper insight and followi
ng these leaders opinions. If these leaders’ pronouncements are found to be c
onvincing then a consensus would emerge.

  ■ As a theorist (I wonder if it's a good identity for you), what is your
opinion for experiment and experimentalist?

  □ To put is succinctly, there can be no science without experiments.

  ■ Can you help me to explain my absurdity? If theorists tell experimental
ists what experiment is worth doing, and experimentalists tell theorist what t
heory is right or wrong (and the theories which can PREDICT are the faves), it
means that physics is something which is deeply depend on HISTORY and is not
invariant by time translation. Then how can we call physics TRUTH?

  □ One should always keep in mind that science is one of the human enterpr
ises. It's not simply some truth being somehow revealed to a select few. Like
any other human activity its development is influenced by social context and b
y history. Remember, even Newton said: I can see further because I stand on th
e shoulders of giants. The form the scientific truth, if you call that, comes
out from the particular set of human interactions and human creativity. To me
this is one aspect that makes doing science so interesting.

  ■ Why you decided to study physics? And why you decided to be a theorist
but not an experimentalist?

  □ My own case is not any particularly "lofty" story: When I was in colleg
e in the early 1960's, it's simply "in the air" – many good students interest
ed in science tend to gravitate into physics. In the States, after the World W
ar II physicists have a fairly high social status (they invented the atomic bo
mb!). Furthermore, the Soviet success in launching the satellite caused the US
government to "panic" – fearing that they were falling behind the Russians i
n science and technology. Quite bit of resource was poured into physics. For u
s Chinese students coming to the West to study, there were two additional reas
ons. Most of us coming to this country studied science and engineering because
it is perceived to be least dependent on a student's cultural background and
language ability. The second reason was Lee & Yang's 1957 Nobel Prize. They we
re the heroes for the overseas Chinese population. There was finally something
we Chinese could be proud of. I give you an example: It was my high school te
acher (of English) in Hong Kong who came into our classroom, with tears in his
eyes, telling us that two Chinese physicists have won the Nobel Physics Prize
. Obviously such social atmosphere had an impact on all of us.

  Theorist vs. experimentalist: there are several layers of reason. I was a
pretty good classroom student. As I mentioned above, this means that I am reas
onably equipped to be a theory student. On the other hand, I knew that I was n
o good with equipment. Thus while I have the patience to chase a minus sign in
a calculation for several hours, I was not willing to spend a lot time fixing
a leak in an experiment. I am sure the peer pressure of "good students going
into theory" that I mentioned earlier also had an effect. Looking back, there
is another reason. In the 1950 and 1960's the physics world was completely dom
inated by particle physics. But to be a particle physics experimentalist, one
had to work with a large team and travel far to accelerator centers; I was not
attracted to such a life style.

  You may ask next: "are you happy with your decision?" Looking back I would
say: "it's the right choice for me." Still on occasions I did wonder whether
as a theorist I was contributing much to physics. For an experimentalist, whil
e not making any spectacular discovery, a patient measurement of some physical
quantity is nevertheless a good honest contribution to physics. On the other
hand, an irrelevant theory paper is often no use to anyone. After many years d
oing what I do, I now have a better understanding of my own situation. First o
f all, I finally understand why I have enjoyed doing what I do. Most physicist
s got into the field because they have a burning curiosity of wanting to know
how things work. A typical type is the one who, even when very young, would ta
ke things apart to figure it out. I was not that type. What I enjoy most doing
in theoretical physics is the pleasure of seeing how beautifully the universe
are put together – the aesthetics of physics. This is also why I enjoy writi
ng books – collecting items to show how a good theory can bring so many dispa
rate parts together. As it turns out, I also enjoy teaching very much. I do it
reasonably well because I find explaining things well to be a real pleasure a
nd because I do have the ability to empathize with the students who are trying
to learn.

  The point I want to get across is that there are many paths to a fulfillin
g life. One does not need to be a "genius" to do theoretical physics.

  ■ You said that you'd like to "collecting items to show how a good theory
can bring so many disparate parts together". Is it only a hobby for order or
it is what our world should be? Then what do you think about the aesthetics in
physics?

  □ No, it's not just some hobby. It is the driving force behind my work, m
y calling. Although I have only made minor contribution to physics, I am proud
to be a "foot solider" in this movement of people who try to understand Natur
e. It is based on the FAITH that Nature is comprehensible. Of course there is
no reason that Nature would have an ORDER that we can understand. But the past
experience has amply justified this belief. It still seems remarkable (I woul
d even say "deeply mysterious") here one would do some calculation on a piece
of paper; at the other end of the world someone can make a measurement and fin
d exactly what that calculation say what should be the number.

  As Einstein once said, what's most incomprehensible about Nature is that i
t is at all comprehensible. To say that the physical world is comprehensible t
o me means it can be described in a simple way. Such a description (stated in
our physics theory) to me is such a beautiful thing. This is the aesthetics in
physics that is so appealing to me, this is the aesthetics that I find it so
uplifting and I want to share it with others.

  ■ Besides enjoy "seeing how beautifully the universe are put together", d
o you think beauty matter to you in other places in life? Does it change your
life style, or does it change your opinion for society and human being?

  □ Are you asking me whether beauty is important to me in other aspects of
life. I would certainly think so. I do appreciate any civilization that pays
a lot attension to artistic aspects of life. I would say any great civilzation
, I would say almost by definition, has a great art. Whether it changes my lif
e style? I suppose it is inevitably reflected in one's life. Does it change my
opinion of a society? From the above answer, it probably does. Opinion of a h
uman being? Yes, I do probably admire an artistic person more --- but hopefull
y that is independent whether that person is endowed with the kind of physical
beauty as judged by the conventional standard.

  ■ Is physics important to you in other aspects of your life?

  □ In my own case the answer is no; I certainly do not find particularly u
seful to make analogy of other matters in life to physics. Of course as a phys
icist we have certain ability for critical thinking that is carried over when
considering other things in life. But I certainly do not claim that only physi
cists have the critical thinking ability. I would say any educated person (her
e I do not mean formal education that earns one a degree) should be capable of
critical thinking.

  ■ Do you ever feel tired? Are you ever despaired of researching (and if y
ou were, because what)?

  □ Of course I do get tired and often get discouraged with my work. This i
s entirely normal. Still, I want to emphasize something that I said in another
context. Doing research is hard, but it is not as hard as a young student oft
en thinks. As I pointed out, once one is deeply involved, it is often a matter
asking a straightforward, common-sensible question --- this is called researc
h!

  Just by asking this question it shows that you have not "said good bye to
your fantasy" yet. I suppose you think scientists are all super human beings t
irelessly seeking truth. No, the truth is that scientists are just like any gr
oup of human beings. It is true that because there is some objective criterion
to judge (eventually) whether something is right or wrong. It has by-and-larg
e relatively healthy methods to settle disputes. But physicists are human bein
gs and they have all the failings of human beings. (So, I don't think any less
of them.) They still fight over prestige and power, just like any other group
of people. Still, by comparison it is a relatively "clean" profession.



  ■ For a young student who want to study physics because of interest, how
can he or she judge whether his/her interest can be lasting?

  □ This is a hard one. No one can see the future. But by and large when on
e is young one tends to have more energy and one's senses are sharper. As an o
lder physicist once said to me, "when you are young, the world is ON FIRE: eve
rything is interesting and exciting." This will propel one to dig deeper into
things. As one grows older, one tends to be mellower. But it's a relative thin
g. We say theoretical physicists tend to do their best work when young. On the
average, this may be true. But there are plenty theorists still doing good sc
ience past their 60's, especially if they started out at a high level.

  Yes, one has to be honest with respect to one's own interest. Does the sub
ject really excite you? how is this interest compared to other interest of you
rs? I would not worry too much about the future. Rather, one should say to one
self; "whatever I do, I want to do the best I can. I will keep an open mind, a
nd I will welcome change."

  ■ Can an experimentalist be a good physics teacher?

  □ In my earlier messages I may have defined teaching too narrowly (as cla
ssroom teaching only). As I said most physics classes are essentially theoreti
cal physics classes. At a superficial level a person with a stronger theory ba
ckground would have an easier time to teach such classes. But I personally hav
e had really good classroom teachers who were experimentalists. They were able
to explain things in more concrete terms (not hiding behind math!). But I mus
t say that most advanced courses, say graduate level electrodynamics, quantum
mechanics and quantum field theory, are usually taught by theorists. On the ot
her hand an experimentalist graduate students get most of their training in th
e actual laboratory. There the teaching goes on in a one-to-one basis.

  Related to this, let me give you some historical examples. The two physici
sts who had been credited for bringing American physics to the preeminent posi
tion in modern era (in the 1930s and 40s) were J. Robert Oppenheimer and Isado
r I. Rabi -- one a theorist and other an experimentalist. Both were regarded a
s great teachers. Of course, Enrico Fermi, who built up the great physics scho
ol at the University of Chicago, was both a great theorist and experimentalist
. But Fermi's case is too singular to be used as any sort of realistic example
. (In last 50 years there had not been a particle physicist who could be preem
inent in both theory and experiment.)

  In short, an experimentalist can certainly be a good teacher: in the class
room (especially in undergraduate courses) and in the laboratory where real ph
ysics is done.

  ■ Do you think theoretical physics is for every young student who wants t
o study it no matter he or she is clever enough or not?

  □ An answer to such a question of course also depends on what level one w
ants to operate at. It one wants to be a first-tier theoretical physicist, cle
arly one must have some aptitude for such an abstract subject. But if by this
one means to learn theoretical physics to be able to teach physics and to do r
elevant experimental work, then I would say most students with some diligence
can learn the subject. One must also keep in mind that many preparatory branch
es of physics and mathematics are required in order to study such a subject li
ke quantum field theory and theoretical particle physics. One cannot be too an
xious to learn the subject in too short a time. For example my book with Profe
ssor Li on gauge theory, while considered by many to be a particularly accessi
ble presentation of the subject, is nevertheless intended for more advanced gr
aduate students. If undergraduates try to learn the subject this way, typicall
y they would, through no fault of their own, find it tough going. This is even
more so when comes to the subject of supersymmetry and superstring. One has t
o be a bit patient by taking one step at a time. Otherwise one can easily get
discouraged.

  ■ You have said to me that "in the States it is still somewhat rare to fi
nd a woman particle physicist". Do you ever have female physical students? How
they studied? Do the male and female physical students have any differences b
etween each other (I mean, thinking style, etc)? Then you think why there are
fewer women studying physics than men (in China and in the Western world)?

  □ No, I have not had a female PhD student yet. But for that matter I have
not had many male graduate students either --- because I am located in a smal
l department and robust particle physics graduate programs tend to be with lar
ge Universities. About one third of our undergraduate physics and astronomy ma
jors are women. Female students do just as well as male ones. I do think it's
mainly sociological reasons why there are not many women particle physics stud
ents. It's understandable a woman would be more reluctant to enter a field whe
n she does not see many persons of her gender in the field. Besides the questi
on of lacking role models, in any field of study it is very advantageous to ha
ve a peer group with whom on feels comfortable to have frequent relaxed exchan
ges – in fact most of us learn a good part of our subject through discussion
with our peer group. Of course in principle men and women can form a study gro
up – in reality there is still some barrier nevertheless. Once there is a cri
tical mass of female particle physicists there will be many more women coming
into our field. I am convinced this will happen in the not too distant future.


  As the same time I do not wish to be too naive about the subject: The soci
al barrier is quite real. To a good extend this is true for any demanding fiel
d of endeavor. Our society still treats men and women differently and there ar
e biological imperatives. While most men have the support of spouses who do mo
st of the household chore and child rearing, a woman-professional still has to
do both career and domestic work. (This is definitely changing in the West, a
nd I assume the same in China also.) During the child bearing/rearing age (20'
s and 30's), it is simply too difficult for a woman to devote totally to physi
cs during this crucial stage of their life. So there are definitely barriers.
But there certainly have been many cases people have found ways to overcome su
ch difficulties. On the other hand, if one is talking of living a satisfying l
ife, making contribution to the physics, one can still do it with a more balan
ced life. As I said previously, one can lead a successful physicist life witho
ut being at the very top of the pyramid.

  ■ What kind of social environment is good for a young student to seek sci
ence (I am sure it's not an environment where everyone wants to have an easy a
nd comfortable life, just like nowadays in China)?

  □ I am not sure exactly what you meant by this question. I will proceed w
ith the hope that I guessed correctly what you are trying to ask. Generally sp
eaking, to learn such a difficult science subject, it is a good idea to have s
tudy partners. Ideally it's a group of friends, with similar interest, studyin
g together. The main advantage is that in such a group there will be free exch
anges and mutual discussion so that one is not afraid to ask "stupid questions
". It is immaterial whether this group consists of all the "good students", et
c. Clearly if the study partner knows more, it's useful. Even if the partner k
nows less, it is useful also. In the process of helping the partner by explain
ing a difficult topic, one also learns tremendously. As the saying goes, the b
est way to learn something is to teach it. One should also be aware that just
about everyone feels "stupid" when learning science, especially physics. Actua
lly it is not that the learner is stupid, rather it's the nature of the subjec
t matter. If the person answer your question knows what she or he is talking a
bout, the answer is often straightforward, thus "obvious" --- hence making you
(the person asking the question) feeling stupid. Because science is a system
with logical structure, all correct answers should be "obvious". Clearly, this
should not prevent one from asking questions, but one should be reminded that
this is just the nature of science.

  I don't know what you meant to say the prevalent environment in China is t
hat people only seek an easy and comfortable life. From what I know this is ju
st the opposite: everyone in Chinese schools work very hard. (My concern is th
at people work TOO hard and leave no time for self-development.) Frankly, I am
not bothered by the fact that people want a good life. This is just human nat
ure; it's entirely normal. What concerns me more it that students study a subj
ect not out of true desire to learn, and not out of an innate curiosity, but j
ust out of the "duty" to study something that they think will bring them prest
ige in the society they live in. This kind of motivation seldom brings self-sa
tisfaction or great achievement.

  ■ What I mean "easy and comfortable" is what you mentioned at the end of
your answer, because I think "prestige in the society" is a life easy and comf
ortable. I have never studies in the western countries, but I am told that Chi
nese students always do the best in the western Universities and none of them
(I mean the persons just a little older than me) do the best in the scientific
society nowadays. What I wonder is that there are a lot of Chinese scientists
who are the best in the older generation (I think if they have their childhoo
d in Chinese mainland, they were all born before 1949). So I ask you what kind
of social environment is good for a young student to seek science, because Ch
inese traditional culture should be all the answer.

  □ First of all, I am not so sure that older generation had any better edu
cation back in China than the current system in Mainland. In my opinion, consi
derable statistical chance is involved in any "great" scientific discovery. Th
ere are more good scientists who are older simply because there have been long
er time for this statistical odds to happen. I also do not agree with the obse
rvation that somehow the younger Chinese scientists have achieved less (vs the
older ones at comparable age). There are many outstanding Chinese scientists
here in the States. Yes, no recent Nobel. But that's what I mean by statistica
l chance. Also keep in mind that many Nobel prices are given for work done man
y years prior. Please note this recent physics Nobel for Gross, Wilczek, and P
olitzer was for their work done in 1973. (That's why we often joke that a basi
c criterion to win a Nobel is longevity.)

  Now there may be some truth that the research achievement of Chinese does
not quite match their performance as students in a classroom setting. That has
a lot to do with our culture of not emphasizing independent thinking. Chinese
, whether young students or older adults, are seldom told to cultivate the att
itude of QUESTION AUTHORITY! Also the education system here is different. Amer
ican students have to spend a lot time, starting even in elementary school, to
do independent projects, many of which involve team-work. In a sense here a y
oungster starts "doing research" very early.

  Another interesting difference is the emphasis here on developing a young
person's social skill. (May be there is too much an emphasis.) But in science,
like any human activity, the ability to be independent-minded and at the same
time the ability to work well with others are very import for eventual succes
s. In the Chinese education system (for that matter all Asian education system
s) only the competition aspect is stressed. For example, to me, the falling-ou
t between Lee and Yang is not totally unrelated to this lack of social skill.
To be sure, falling out between collaborators certainly happens; but seldom on
e encounters such bitterness and such public squabble.

  ■ You said that in the Chinese education system, competition is overempha
sized, but Lao Zi told us to know where to stop (知足不辱、知止不殆，可以长久)
so competition is not a Chinese traditional culture, and the culture which ov
eremphasis competition is Greek (they said Olympic). So you think when and why
we began to overemphasis competition?

  □ The nature of East and West competitions are somewhat different. While
the West tends to emphasize the direct competition among different people, but
I would still regard Chinese culture emphasizes competition – although mainl
y in the form of competing with oneself, or competing to win with respect to s
ome fixed expectation. What I have in mind is this all-important role that exa
minations have traditionally played. The goal, set for every student, is to do
well in these exams, to be the number one, to be the 狀元. There is this expe
ctation that studious study would translate directly into fame and fortune (no
t mentioning power). This is so deeply ingrained in our culture, even today al
l sorts of people are still surprised that the number-one student in a school
does not do all that well in life after graduation. One seldom sees students b
eing encouraged to learn for the sake of learning --- not many people talk abo
ut the "joy of learning", or the "joy of reading", etc., to acquire knowledge
so as to be able to live a full life. Instead, youngsters are told to "eat bit
terness": if you study hard, it will bring you glory and fortune, so-on so-for
th.

  You mentioned Lao Zi advocating this passive approach to life. For that ma
tter, we also have Buddhism which told us "all is illusion" .., the only way t
o live is "to give up all human desires". Yes, these traditions are there. But
I claim they are all "side-shows". Asian societies have been dominated by the
Confucius value of "doing all you can to gain honor and glory for yourself, y
our family and your country". For those wanting to drop out of this "rat-race"
, they are offered Taoism and Buddhism – these are society's mechanisms to "l
et-out-the-steam" so that the principal business of competition can go on.

  ■ Then what is your definition about success (especially success for a ph
ysicist or a scientist)?

  □ What is my definition of success? Everyone is given some natural abilit
y and circumstantial chances. Any person can be counted as "a success" if she
or he can fully utilize these potentials to do something useful to mankind. An
other component of being "successful" is one's own well-being which, for me, m
eans the possession of meaningful and warm relations with people around one-se
lf. For those of us who have been fortunate enough to live a life without the
need to struggle constantly to gain the basic necessities of life, one should
get involved with something that transcends the daily humdrum, that's benefici
al to mankind. In my case it turns out to be physics and education. But in my
opinion exactly what one does, whether it's geology or physics, whether a scie
ntist or a shopkeeper, whether a university professor or a craftsman, is reall
y not that important. What's important is doing it well – to the best of one'
s ability.

  You also asked for the definition of a "successful scientist", specificall
y, a "successful physicist". A "successful scientist" is someone has made mean
ingful contribution to the advancement of science. That's of course a tautolog
ical answer. What one should keep in mind is that the advancement of our knowl
edge can take on different forms. The most clear-cut advancement is making new
discoveries. But everyone has different abilities; there are scientists who c
ontribute by having a deeper understanding of things that have already been di
scovered, by seeing new relations among known things. Also we can contribute b
y being good teachers, or by being a good science reporter, or being a good ad
ministrators, etc. All are very useful to the progress of science.

  I suppose, when you ask such a question, implicitly you are asking me to t
ell you as a young person: how can you be a successful scientist? What I am tr
ying to say is that, at the outset, it's not very important whether you are in
this or that field. As everyone has different abilities and is given differen
t chances, you should allow yourself to explore different opportunities. You s
hould then pick the one that you find you have particular affinity to – your
particular talent or interest that will allow you to dig deeply into the subje
ct (namely, having a passion). In such a situation there is better chance that
you will "do well".

  One thing a young person entering a field always worries about not having
the ability "to make discoveries". All those discoveries one reads about alway
s seem so "clever", or the process has been "completed" and there is no more d
iscovery to be made. Actually most often the new discoveries were merely the c
ommon-sensible "next-steps" made by people who are deep involved in the study
of the subject. Thus the most important thing is to get oneself involved (as w
e say, to get one's feet wet), then step-by-step, till one becomes "deeply-inv
olved". Once in that stage, new discoveries will come naturally. Related to th
is "fear" of not having the ability to be a scientist is related to the type o
f exposure students have had of the science subject. Often a student doesn't r
ealize that the way science is taught in a classroom is very different from th
e way science is actually done. In a classroom, what's taught is some neatly "
packaged-science". In order to teach what has been learned in the last two or
three hundred years of scientific discoveries, the only way is to present the
summary, the result. Presented this way everything seems so logical, so self e
vident. This is seldom the way the scientific results are actually obtained. I
n physics this means what's learnt in a classroom is the resultant theory. Tha
t's why most physics students want to be a theoretical physicist, because all
they have seen is the triumph of theory.

  ■ What do you think about a leader (I mean, a leader of a big science pro
ject you and me have to contact with, and also some leader in other places)? D
o you think "leadership quality" is important for a physicist?

  □ A leader is naturally important because, if her/his deed does cause a g
reat following, then, for better or for worse, it's important. Such a leader c
an have the kind of personal quality that naturally draws others to him/her. B
ut s/he can also be a "loner"; but by the sheer quality of her/his work or vis
ion that causes a great many people to look up to her/him. With such a broad d
efinition of a leader, there is not much one can discuss further. But I believ
e you are asking about the kind of leader who can organize others to accomplis
h a task. Clearly a big science project can only be done if there is a small s
et of leaders pointing the way and providing the administrative organization.
I think such leadership is very important. In most academic circles people ten
d not to value administrators, and it's true that many administrators do not c
ontribute much except to their own benefit. But I think they are wrong. Over a
nd over again I have seen administrators who can provide leadership and their
service has genuinely benefited the people in the organization. Often such typ
e of leadership has proven indispensable for a difficult task to be accomplish
ed. Such leadership quality should be highly valued by a society.

  In fact I would say that the traditional education system in China, for th
at matter throughout Asia, has not put enough emphasis on cultivating such lea
dership quality in the young. Now I am talking about education in general rath
er science education in particular. The way being done here is to have childre
n, at a very early stage, participating in group activities. Of course, you mu
st involve them in doing things that they are interested in. The most common a
ctivities are team sports, which is a great way to foster friendship, cooperat
ion, and cultivate leadership among the young. Leaders and leadership are impo
rtance at all level of a society. I certainly do not mean the kind leader who
is a dictator who has the habit of imposing his/her will over other without ar
tful persuasion. While our culture had not emphasized the importance of cultiv
ating leadership quality in a significant portion of the society, we often put
too much value and hope of having one "great leader", "the savior", who would
lead us to paradise (secret hope for a "wise king"). One has to realize that
a leader is a human being after all; when too much power is given to a person
for too long, it has great corrupting effect. This is certainly true in politi
cs, but also in other spheres of activities. Any organization should have a na
tural way to allow fresh new leadership to replace the old.

  ■ What do you think about a leader as a person and a leader as a rule? Th
en what do you think about a physical rule we cannot revolt?

  □ I suppose you mean one's attitude towards the established orthodox: whe
ther it be a body of knowledge or persons in power holding orthodox views. In
this regard I would say science is generally a fairly conservative community.
Namely, we do not give up a well-established theory (orthodox?) lightly. For a
comprehensive theory to be established, typically it has passed many, sometim
e tens of thousands, experimental and observational tests. If some new phenome
non is discovered, one tends not give up the old theory right away. First of a
ll, one has to make sure that the new observation is genuine (I have certainly
seen my shares of wrong experimental results) and one then tries to understan
d it in the old framework --- to see whether the apparently contradictory evid
ence can actually be comprehended because the established theory may have so-f
ar not realized richness in its structure to include such new phenomenon. In t
his case the Standard Model of particle physics is a good example. Quantum fie
ld theory was the first framework people used to understand the particle inter
actions. But QFT calculations led to infinities. Only after a long struggle di
d people realize that if the calculations were performed correctly (through th
e renormalization program) then these fatal infinities went away. Then in weak
interactions the infinities one encountered were above and beyond those curab
le by renormalization; people eventually learned QFT could be in a "spontaneou
s symmetry breaking phase' (the Higgs mechanism) giving rise to a massive inte
rmediate vector boson theory that is renormalizable. In the realm of strong in
teractions the unexpected richness of asymptotic freedom and confinement, etc.
allowed us to construct the successful QCD. So in the end QFT was the right f
ramework after all, even though along the way many people had advocated its ab
andonment as the framework of high energy physics. You can certainly revolt ag
ainst orthodoxy but usually this is not the first thing one does when encounte
ring a new difficulty. Obviously quantum mechanics was a revolution. But it wa
s made after many years of trying to accommodate the new radiation and atomic
physics within the classical theory. Such a radical break was accomplished by
young students (Heisenberg, Dirac and Pauli all were in their early 20's) whos
e mind had not been conditioned by the old physics and could look the difficul
t in a new light to invent QM. Schrodinger was in his 30's when he first wrote
down the QM wave equation; this "old man" of quantum revolution in the end ne
ver was able to come to term with the new QM.

  I am not saying that one cannot revolt against a physics rule. Because the
rule sits on a very firm foundation, it is often difficult to replace it by a
new one that can explain not only the new difficult but also leaves the old s
uccesses untouched. Thus in physics there is seldom a revolution that knocks d
own the old and replaces it by the new. It just find a new that is more encomp
assing : it can include the new as well as the old.

  ■ If we analogize physical theory as ordinary leaders, we may think physi
cal rules/truth (I mean, something like final theory nature really hold --- al
though maybe it is not comprehensible forever, not the theory we have now) as
"great leader". Then, what do you think about physical rules/truth?

  □ Physics laws as leaders?! This is an interesting exercise on analogies
--- not one I would have thought of, but I will try. Such leaders would not ha
ve been appointed by someone. They would have reached their leadership positio
n through a whole series of difficult tests. Eventually all come to recognize
and accept their leadership willingly. But such a leadership is very inflexibl
e and they have to be obeyed all the time. There have been revolutions in this
realm also. Usually such leadership are not over-thrown but absorbed into a b
igger domain where an even greater leader rules. Still, I am glad we are just
playing a game here. I would not want to be governed by such a leader. To me a
wise leader has to be flexible and taking the human nature into account in it
s ruling over a society. I certainly do not wish to live in a society ruled by
a rigid tyrant.

  ■ Do you mean you do not believe final theory?

  □ If you mean by final theory in physics, I do believe it --- subject to
the qualifications I have been talking in the above: Physics theory is always
subject to revision when new phenomena are discovered. We must also keep in mi
nd that there had been occasions in the past when people mistakenly thought th
at the end of physics was at hand. Also, a “theory of everything”, while pro
vides a nice the global connection of different parts of physics, really does
not explain most of things in physics.

  If you mean by final theory in this analogy about leaders, I certainly do
not believe in any ultimate leadership thing.

  ■ When you last came to China (I mean both mainland and Taiwan respective
ly if you have ever been to)? How do you feel about it?

  □ I was born, and finished junior high school, in Shanghai. In 1956, duri
ng the "Hundred Flowers" period, my sister and I were able to obtain exit perm
it to go to Hong Kong to join our parents. I finished high school in Hong Kong
and have been in the United States ever since 1960. My wife is from Taiwan, s
o we have been going back to Hong Kong and Taiwan almost every year. So I know
a bit more of those two places. The first time I went back to Mainland was at
the end of 1979 because there was a physics meeting organized by the Chinese
Academy of Sciences held in Conghua (just outside Guangzhou). There was chance
for us to visit Beijing, Hanngzhou, and Shanghai also. Since then I have only
been back two or three times for very short visits – not in any sort of offi
cial capacity. Last year my family and I did a tour of Beijing, Xian, and Shan
ghai. On this trip I visited Peking University and two institutes of the Acade
my of Sciences. In fact some arrangement was made that would allow me to come
back to teach for a year at Peking University. But in the end, I have to decli
ne this very nice invitation because of some personal obligation that would no
t allow me to leave St Louis for too long a period. How do I feel about these
places? Of course I have been very much aware of the big change happening in C
hina. From the news reports, and from reports of friends who have gone back to
visit and some to stay. I also had PhD students coming from Mainland. To actu
ally see the physical transformations was certainly mind-boggling. What surpri
sed me was that, while people at the top (for example, the scientists at the A
cademy) were happy and optimistic, many the people we encountered on the stree
ts expressed tremendous anxiety. Among other things, so many of them were worr
ied for their children to be able to enter a respectable university. The feeli
ng was that failing to do so would somehow "doom" them forever. There is this
whole hierarchy of education institutions. The right "brand name" is so import
ant to everyone. I believe this problem is not peculiar to Mainland. This kind
of value is more or less true in every Chinese area in the world: in Taiwan,
in Hong Kong, in Singapore, and also in the Chinese community in the US. Someh
ow our traditional culture put so much emphasis on a hierarchical structure. E
very thing has to be ranked, even though the rankings themselves are often mea
ningless. Somehow, people cannot exercise their independent judgment and they
put so much faith in "name-brands" as given by these rankings. In Taiwan and i
n Mainland, to exploit this weakness all sorts of books are written with the t
itle having the word "Harvard": This would guarantee them to be read by all ki
nds of ill-advised readers. So in Taiwan, in Mainland, AND in the Chinese comm
unities in US, people compete so fiercely to get into a few designated places
that would somehow bestow magic power onto their children. So much sacrifice i
s made for this -- such a waste of energy and talents! But this is very deep i
n our tradition. It would take many years to cultivate a new culture of indepe
ndent minded and critical thinking people. But I hope it will happen.

  ■ Do you think there are something important enough as we should ask you,
but we did not?

  □ You have asked many thoughtful questions, and have been very patient wi
th my often long-winded answers. Please indulge me with a few more "final comm
ents".

  I hope every student should realize that no matter how much one learns in
a university it will not be enough --- especially in view that so much knowled
ge becomes obsolete in a not-very-long period. Thus the most important thing t
o learn is how-one-can-keep-on-learning after school. Namely, one must acquire
the habit of “life-long learning” --- the habit of constantly reading, with
a critical mind, books, magazines and internet postings... by whatever method
s knowledge is being propagated in the world today. No one knows the future; b
ut we can be sure CHANGE will be a constant feature in our lives. The best pre
paration for an uncertain future is the habit of constant self-learning.

  Just by studying in a classroom is not enough in another sense. In this in
terview we have talked mostly about physics and science education in the forma
l setting – the type you study and take examination at the end. To me there i
s always the danger that a student learnt all the technical aspects of science
and technology without absorbing the more important lessons of “having the s
cientific spirit”. This means a broad outlook, a habit of making judgment bas
ed on evidence, a critical eye towards opinions one hears from all directions.
I bring this matter up because the Asian education system that forces a stude
nt to specialize at a very early age (certainly by the start of the university
period). This has the danger of producing rather one-dimensional specialists
who may be very competent in the technical details of their profession, often
lack sound judgment when making important decisions. The solution is to de-emp
hasize examination at every level ant to allow undergraduate students to postp
one their specialization until the last two years of their university career.
This not only gives more time for students to decide exactly what their intere
st lie but also can expose them to a broader “liberal arts” learning. Such a
reform is likely to be resisted by the education establishment because it giv
es more control to the students. “Who knows what students would decide to maj
or after we admit them?!” But if enough people start demanding such a reform,
this will happen someday.

  Finally, I would like to pay you and your magazine a special compliment. T
he interview collection you have posted online is among the most informative t
hat I have read about the education situation in China. The activities that yo
u and other young people are engaged in (the NGOs) are very impressive. I know
the situation in China is not easy, but what you all are doing will make a di
fference; this gives me great hope.

  2006.07.26 -- 2006.08.31 network interview / translate by H.O.L.M. The tra
nslator do not want to guarantee the validity and accuracy of the Chinese text
, because of her limited capability. Please read the English version directly
if you have the ability. The interviewee's wife Leslie Su Cheng has great cont
ributions to the translation, in fact, she pointed out a lot of mistranslation
s of mine and helped me to translate something. My friend dk provided some hel
p for set up questions, she also read my preprint and gave me a lot of advices
. The text of this interview belongs to Creative Commons Deed (Attribution-Non
Commercial-ShareAlike), you can share it in this legal restraint.

－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－

徐一鸿 / Tony A. Zee

　　■ 你认为具有怎样标准的东西才能被称作“标准模型”？(1)

　　□ 在物理上有很多名词取得很不好。比如爱因斯坦自己说“相对论”就是一个例子，
很多人根本不懂相对论，就把它理解为真理是相对的，没有确定的终极理论。“标准模型
”这个名词也取得很不好。首先，它本应该被叫做一个“理论”而不应该说是一个“模型
”，就像麦克斯韦的电磁“理论”一样。现在在美国名词被搞得很糟糕，甚至在政治上很
多东西都被叫做“理论”，但是其中的很多是不合适的。另外“标准”也是一个非常不好
的词。

　　■ 你怎么看待“基本粒子标准模型”和“宇宙学标准模型”？(2)

　　□ 这两个标准模型应该是不同等级的。相比之下，“宇宙学的标准模型”的整个图像
将来还可能有很大改变，甚至被整个推翻。

　　■ 作为一个物理学家，你怎样看待数学？(3)

　　□ 在物理学界有很多人很推崇数学，我有非常不同的看法。我的看法比较像费曼。


　　■ 从物理的角度，你怎样看数学中的一些深刻的定理，比如说“哥德尔不完全性定理
”？(4)

　　□ 这种东西对现代物理上一点影响也没有，它们只是在比较深奥的数学上被发现的。


　　■ 那么你理解数学真理和物理真理？(5)

　　□ 数学只是一种逻辑关系，它当然很奥妙，但是不一定和现实生活有联系。所以我觉
得这两种真理是两个不同的领域，虽然它们有时会有相近或者重叠之处。我不同意有些人
说物理和数学是统一的，它们最终会走到一起，不过这种说法在中国特别多。

　　■ 你怎么看待哲学？它是否能对我们的物理研究有所帮助呢？(6)

　　□ 你知道物理刚开始的时候是哲学的一部分，其实它在历史上就曾经被叫做“自然哲
学”。但是在最近两三百年内，“科学”的概念增加了。我觉得哲学对物理学是有影响的
，但是这种影响是在社会层面上。如果你想做物理，并不需要去看哲学书。

　　■ 你怎样看待“自由意志”？(7)

　　□ 我当然希望自由意志是存在的，因为如果它不存在我们做的一切都没有意义。如果
它其实不存在，那就是很让人沮丧的事情。但是我们不知道怎样从物理（科学上）来理解
它。

　　■ 你怎样看待实验在物理上的意义？(8)

　　□ 实验当然非常非常重要，因为物理学归根到底不是一个游戏，它就一定需要实验。
最近三十年来弦论的发展是一个反例，因为没有实验的指导，TA们会越走越偏，我不知道
TA们怎么走出来，我也不知道弦论到底是对还是不对。与此不同，麦克斯韦的电磁理论在
19世纪的发展就是很依赖实验的。

　　■ 也就是说你本人很不喜欢弦论了？(9)

　　□ 不，我很喜欢它。我觉得你问的问题和我是否喜欢它没有什么关系。如果我是年轻
人的话我会去做弦论，在某种程度上它是很吸引人的理论。但是弦论却到了不知道会走到
什么地方去的地步，它有自己的数学结构，但我们相信它却只因为它的数学结构。

　　■ 你是否能够帮助我解释一下我的悖论？如果理论物理学家告诉实验物理学家什么实
验是值得做的，而实验物理学家告诉理论物理学家哪个理论是对的或者错的（那些能够预
言实验的理论是我们的最爱），这意味着物理是某种强烈依赖于历史并且并不具有时间平
移不变性的东西。由此，我们还怎样能把物理叫做“真理”呢？ (10)

　　□ 你的问题可以在不同层面上说。我们可以想象另一个文化存在于另一个星系里面，
TA们的科学历史和我们的完全不一样，比如TA们也许先发现了相对论，但是 TA们一定有和
我们一样的科学和一样的真理，所以你是错的。但是其实你刚才提到另一个更重要的问题
，现在很多粒子物理实验太大太贵了所以只能做一遍，而不同于以前很多实验都做很多次
。这非常不好，因为这使得做实验的人很容易受做理论的人影响。

　　■ 怎样判断在物理中什么是重要的而什么不重要？(11)

　　□ 这件事情很难判断。在十九世纪如果研究电磁学，或者比如蛙腿电击的问题，大家
就都会觉得很不重要。她/他们当时会认为流体力学是重要的。但是事实证明电磁研究就很
重要。

　　■ 对于一个学过量子场论的人来说，回顾牛顿力学，你是否能发现一些更深刻的东西
？(12)

　　□ 当然。你起码会知道量子力学是如何从量子场论中近似而来的，而牛顿力学是如何
从量子力学中近似而来的。

　　■ 你怎么看待那些我们说“是”或者“不是”的物理词汇？或者说，当我们只对某些
命题回答“是”或者“不是”时，是否能够获知真理？(13)

　　□ 我不知道真理是否可以简化到这种程度，但是我觉得应该不可以。有很多事情是不
可以只说是或者不是的。

　　■ 是否存在“物理学的思维方式”这种东西？(14)

　　□ 有。不过物理学是一个很大的范畴，它的不同分支思维方式也有很大不同。

　　■ 物理学对你生活的其它侧面是否重要？(15)

　　□ 你指的是理论物理吗？这个要看你对生活怎么定义。我想它对我应该是重要的。


　　■ 你是否认为理论物理适合于任何一个有志向学习它的年轻人，无论她/他聪明与否
？(16)

　　□ 你当然也可以问一个小孩子学写字是否需要足够聪明。她/她不够聪明当然不行。
不过这同样是针对各个细化的分支而言的。比如如果你做原子物理，大概就需要很仔细很
认真。

　　■ 对于一个因为兴趣而跑去学习物理的年轻人，她/他怎样判断自己的兴趣是否能长
久呢？(17)

　　□ 你的问题不太有针对性，上面这几个问题完全可以适用于其它方面。比如你完全可
以问她/他下棋或者打球的兴趣是否长久。这个要看她/他对自己的期盼，如果她 /他只是
想玩一玩，那么就可能会很感兴趣。但是如果她/他是想比赛并且想赢，她/他实力不行很
快就会没有兴趣了。

　　■ 你怎样定义一个物理学家的成功？(18)

　　□ 中国在20多年前有一段时间简单的把成功定义为获得诺贝尔奖，这个是很片面的。
得诺贝尔奖的人有的是应该得的，但是有的后来就发现其实并不是很重要。关键是要作出
自己觉得重要的工作，使得自己满意。

　　■ 为什么你会决定学习物理？(19)

　　□ 我们这一代人华人学物理都很受李政道和杨振宁的影响。他们的工作是我读中学的
时候做出的。当时我们家从香港移民巴西，我妈妈不知道我们到那边还会不会有学上，就
买了很多书带上，其中有一本物理书。在船上（当时坐船从香港到巴西要50天，不像现在
的年轻人做飞机一天就可以）我在读那本书，就对物理很感兴趣。每个人的经历是不同的
。

　　我有很好的运气，那就是我爸爸租的房子恰好离美国领事馆很近，我可以步行前往，
而那里的图书馆有很多英文书。当然，他租房子的时候并不知道这件事情。但是我如鱼得
水地阅读了那个图书馆里的很多各式内容的书。我记得我曾经读过一本书教我怎样管理一
个森林，比如什么时候该去砍哪棵树，等等。

　　■ 为什么你会决定做一个理论物理学家而不是一个实验物理学家？(20)

　　□ 每个人是不同的，每个人的兴趣也是不同的。

　　■ 你的英文名字（A. Zee）怎样发音？(21)

　　□ Zee[zi:]就是“徐”在上海话里的发音，你问任何一个上海人都知道。

　　2006年9月20日和2006年11月7日，H.O.L.M电话采访。采访用中文进行，因而无法提供
完整的英文文本。感谢徐先生支付电话费。由于两次采访都没有免提电话并且第二次采访
音质很差，问题7 / 11 / 12 / 14 / 15 / 16 / 17 / 18 / 19 / 20 / 21没有录音，文本
仅为大体意思的回顾（采访者并非专业记者，没有记忆经验），遗漏和曲解不可避免，仅
作参考。感谢宿舍和实验室同学，她/他们极大的容忍了我的采访对其正常学习和休息的影
响。这个采访的文本遵守创造共用协定（署名-非商业用途-保持一致），你可以在此框架
内对其进行传播。

－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－

徐一鸿 / Tony A. Zee

  ... ... When my family immigrated from Hong Kong to Brazil, my mother did
not know whether we would be able to attend school there. So she bought many
books, one of which talks about physics, to bring with us. I was reading that
book on the ship (back to then, it took 50 days to sail from Hong Kong to Braz
il, while today's young people only spend one day on such distance), and becam
e interested in physics. I had the immense good fortune that the apartment my
father rented happened to be within walking distance of the American consulate
with its library of books in English. Of course he did not know it when he re
nted the apartment. But I avidly read many of the books in that library, regar
dless of subject. I remember reading a book about how to manage a forest, when
to cut certain trees etc ... ...

(see the Chinese edition for more)

  2006.09.20 and 2006.11.07 telephone interview by H.O.L.M. Because the inte
rview is carryed out by Chinese, we do not offer English edition. Thanks Mr Ze
e to pay the telephone rates. Because the lack of phone hands-free kits in bot
h interviews and the bad condition of acoustic quality, question 7 / 11 / 12 /
14 / 15 / 16 / 17 / 18 / 19 / 20 / 21 do not write down belong to the recordi
ng. That part of the text is just a review of the general idea (because the in
terviewer is not a professional journalist, so do not know the mnemonics), omi
ssion and misunderstanding can not be avoided, please do not take it too serio
usly. Thanks my dormmates and classmates to tolerate me, of course, the interv
iew disturbed their studying and resting. The text of this interview belongs t
o Creative Commons Deed (Attribution-NonCommercial-ShareAlike), you can share
it in this legal restraint.

这个古怪女孩的主页:
http://oxo.sitesled.com/