Knowledge Problem

How Do We Know the Laws of Physics Will Persist?

Lynne Kiesling

I’m not going to go off on a Schroedinger’s cat tangent or anything, but there’s a really neat article in today’s New York Times about the laws of physics. In a nutshell, here’s the dilemma: how do we know that the laws of physics are true? Can we prove their truth in an overall, universal sense, in the sense that explains the order observed in the universe?

This is an interesting question. Think about it: you go about your daily activities assuming that gravity and surface tension and fluid dynamics and all of the other physical relationships that allow you not to dissolve into a puddle of bodily fluids are true. But what’s interesting is that you can’t prove deductively that they are true. Sure, you can falsify all sorts of alternatives, and the relationships that we call the laws of physics are the last ones standing.

Are they merely fancy bookkeeping, a way of organizing facts about the world? Do they govern nature or just describe it? And does it matter that we don’t know and that most scientists don’t seem to know or care where they come from?

Apparently it does matter, judging from the reaction to a recent article by Paul Davies, a cosmologist at Arizona State University and author of popular science books, on the Op-Ed page of The New York Times.

Dr. Davies asserted in the article that science, not unlike religion, rested on faith, not in God but in the idea of an orderly universe. Without that presumption a scientist could not function. His argument provoked an avalanche of blog commentary, articles on Edge.org and letters to The Times, pointing out that the order we perceive in nature has been explored and tested for more than 2,000 years by observation and experimentation. That order is precisely the hypothesis that the scientific enterprise is engaged in testing. …

There is in fact a kind of chicken-and-egg problem with the universe and its laws. Which “came” first — the laws or the universe?

The article then goes on to discuss Plato’s concepts of ideal forms and the laws of physics as an instantiation of those concepts. But we can’t escape the fundamental problem that we are trying to analyze a large, complex system from within that system, and that because of that, we have to assume the orderliness of the system as a fixed point, if you will, in the argument in order to be able to make any progress in understanding the system to the extent that we can.

Fascinating. A very thought-provoking read.