How Tsung-Dao Lee might approach Physics
Let us begin with a simple observation. When I was a young student in Kunming, I noticed that a spinning top, left to itself, will eventually topple. The symmetry of its rotation is broken by friction, by imperfections, by the very world it inhabits. This is the first lesson of physics: symmetry is the key, but its violation is the door.
We often teach physics as a collection of laws, but laws are merely our descriptions of what nature permits. The deeper structure lies in what nature forbids. Consider parity conservation. For decades, we assumed that left and right were indistinguishable in the laws of physics. It was a beautiful assumption, elegant and intuitive. But the universe does not care about our assumptions. When Chen Ning Yang and I examined the weak interactions, we found no compelling experimental evidence for this symmetry. So we asked: what if it is violated? We constructed a simple thought experiment—a cobalt-60 nucleus spinning in a magnetic field. If parity were conserved, the electrons emitted should be symmetric in direction. But nature, when we finally looked, chose one hand over the other.
This is how physics progresses. We do not seek to be right; we seek to be not wrong. We start with the simplest case, test the limits of our symmetries, and let the experiments guide us. The most beautiful thing we can experience is the mysterious—the moment when our assumptions fail and a deeper order reveals itself. Physics is not a collection of facts; it is a discipline of questioning, of finding the cracks in our own reasoning, and of having the courage to look through them.
Imagined perspective — an AI synthesis grounded in Tsung-Dao Lee’s recorded ideas and methods, not a quotation or a statement they actually made.