In our last post on Hořava-Lifshitz gravity we discussed a theory where a symmetry, Lorentz invariance, may not exist on small scales (high energies) even though it does on large scales (low energies).
I attended a talk by Michel Dine which was given at UC Irvine a while ago. He made a remarkable claim: He said that he had some back-of-the-envelope type calculation that led him to believe the number of possible theories where the low energy symmetries vanish at high energies is much much larger that the number of theories where the low energy symmetries hold at high energies.
He took this idea to speculate that maybe we are fooling ourselves trying to work on theories where our low energy symmetries hold at high energies. He didn't say this but this made me wonder: maybe Hořava is on a smart track. Maybe his gravity theory is wrong but maybe more people should consider theories where the symmetries we know and love at low energies do not hold at high energies.
Now, I'm sure demanding symmetries to hold at high energies is the safest thing to assume. Still, it just may be that our low energy symmetries are all violated at high energies.
I'm thinking about planting a Symme tree this Spring. I hear they are very resilient in high energy UV Utah summers and low energy Utah Winters.
ReplyDeleteStan, that's funny.
ReplyDeleteAnyhow P. Horava has done some other things than his work on gravity, which seem to not have as much problems.
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