Quantum Gravity Issues

Most recent answer: 02/26/2011

Q:
I know you've heard from me a lot, but I was wondering about quantum gravity. Is it the inability to renormalize the field equations that make it impossible to match with general relativity? Why won't this work? If the issue of mass generation associated with the Higgs is resolved, would it also solve the issue of quantum gravity? Ya know, gravity only really manifesting in the presence of mass?
- Devon (age 24)
Lansing
A:
Devon-

Yes, the inability to renormalize the field equations (at least without introducing an infinite number of parameters) is indeed the problem. The reason this problem comes up for spin-2 particles (gravitons) is way deeper in the mathematics than what I've followed.

The Higgs business won't do anything to solve the problem, at least not directly. Even photons are sources of gravity, although a single photon has zero invariant mass. Of course, if something weird turns up in the Higgs search (e.g. no Higgs) whatever line of thought that gets triggered might connect up with string theory and the gravity problem.

Mike W.

(published on 02/26/2011)