Internal (gauge) symmetries and spacetime symmetries

tom.stoer

depends on the enemy ...

PhilDSP

Now I have a question bearing some level of radicalness :)

Is there an empirical reason to be led to believe that gravity is (or should be) quantized? Or is it principally a consistency in frameworks that one assumes should be accommodated?

TrickyDicky

I remember having read somewhere a physicist that claimed that gravity was already "quantized" in GR. I will try to find the reference because I can't remember what kind of arguments he used or what he meant.

tom.stoer

There is no direct experimental evidence for quantum gravity, so I would say that the indications are mostly due to theoretical and consistency reasons; but there are a lot ...