Modern Physics Isn’t All or Nothing

My physics crush, Lisa Randall, was recently interviewed by New Scientist about a “Theory of Everything”.  I feel like there’s some context we’re missing, because the first question (“Doesn’t every physicist dream of one neat theory of everything?”) seems really abrupt. But I like her answer. I might quibble and say I think physicists generally hope there is a “theory of everything”, but it definitely doesn’t drive all work. Work on a theory of  everything is just one branch of physics. There’s also a lot of work that doesn’t depend on a theory of everything (biophysics and condensed matter physics are still trying to work out how to basically go from quantum mechanics to everyday life still) and other work that is important to gathering observations that a theory of everything needs to explain (like astrophysical and cosmological explanations showing there might be preferred directions for structures in the universe). Asking this question would be like asking a heart surgeon if fully understanding the human genome is her dream. It might help her job a bit, but there’s a lot of other problems in her field that also need to be solved and it doesn’t really influence her work.

I also liked her argument against mathematical beauty. Math can guide physics, but empirical observation is also important.  When we moved from a geocentric to a heliocentric model, one of the problems with the heliocentric model was that it didn’t accurately predict where planets were in the sky. This was because Copernicus assumed orbits around the Sun had to be circular, because of obsessions about the “perfection” of circles.