atppp's Blog

有关物理学家和还原论

核物理之父卢瑟福曾说过：All science is either physics or stamp collecting. 物理学家生性高傲，认为自己掌握了世界的终极真理。去看物理教科书，你会发现书中充斥着 govern, determine, restrict, ensure 等词汇，比如：万有引力定律决定了太阳系的天体运动 – 仔细推敲一下，你会发现“决定”这个词绝对不是一个中性的词，而带有一种居高临下的统治感和优越感。预言正电子的狄拉克说：..the rest, is chemistry. 说的就是，你们看，物理学已经把基础理论都打好了，剩下的就是你们应用应用物理学定律把各类学科建立起来。有人把这种应用关系发挥到了极致：

哲学就是应用社会学；
社会学就是应用心理学；
心理学就是应用生物学；
生物学就是应用化学；
化学就是应用物理学；
物理学就是应用数学；
数学就是应用哲学。

（因此哲学最牛鼻，他们不但架构了自然科学的基石，更凌驾于自然科学之上，不可一世，怪不得所有屁挨着地都统称为哲学博士。）

古典还原论的这种思维方式是很可怕的，他们胡乱编造等级制度，认为高一级的学科可以完全拆解成低一级的学科，盲目崇拜相对基础的学科。当然，没有人会否定物理学的重要地位，没有近代物理学的发展，就没有集成电路、大容量硬盘，也不会有发现 DNA 双螺旋结构的工具。但是仅此而已，物理学能从第一原理推导出生命起源和具体的进化过程吗？能解释人为什么长两个眼睛一个鼻子吗？能计算人手臂上有几条大动脉吗？不行的话就老老实实的和生理解剖学平起平坐，不要搞等级制度。被称为 “World’s most creative physicist” 的 P. W. Anderson 在著名的批判还原论的文章 More is Different 中提到：

… The behavior of large and complex aggregates of elementary particles, it turns out, is not to be understood in terms of a simple extrapolation of the properties of a few particles. Instead, at each level of complexity entirely new properties appear, and the understanding of the new behaviors requires research which I think is as fundamental in its nature as any other. … At each stage entirely new laws, concepts, and generalizations are necessary, requiring inspiration and creativity to just as great a degree as in the previous one. Psychology is not applied biology, nor is biology applied chemistry.

… but we have yet to recover from that of some molecular biologists, who seem determined to try to reduce everything about the human organism to “only” chemistry, from the common cold and all mental disease to the religious instinct. Surely there are more levels of organization between human ethology and DNA than there are between DNA and quantum electrodynamics, and each level can require a whole new conceptual structure.

In closing, I offer two examples from economics of what I hope to have said. Marx said that quantitative differences become qualitative ones, but a dialogue in Paris in the 1920’s sums it up even more clearly:
– FITZGERALD: The rich are different from us.
– HEMINGWAY: Yes, they have more money.

还原论也许可以作为一个科研人士的信仰，或者也可以成为骗取经费的说辞（你们怎么可以不给研究自然界终极理论的学科投钱呢？），但是不可能成为推动科学进步的原动力。更多阅读：

• Richard Dawkins: The Selfish Gene
  
• Stephen Wolfram: A New Kind of Science. 这个发明 Mathematica 的大牛消失了一段时间写出来这本极具争议的巨著
• Steven Weinberg: Is the Universe a Computer? A New Kind of Science 的书评
• M. Mitchell Waldrop: Complexity: The Emerging Science at the Edge of Order and Chaos
• P. W. Anderson: More is Different

Tags: complexity, physics, reductionism