Quantum gravity vs. general relativity

[tom.stoer]

That seems to be rather interseristing for special cases in QM. But how does it affect my statement "even in well-understood theories like QCD the plane waves are a very poor approximation ..."?

 

[Bob_for_short]

Plane waves are the initial approximations for PT calculations. My simple QM example may serve to estimate the meson masses from PT calculations. Concerning three-quark baryons, it is probably harder but I think it is still possible.

Of course, the plane waves without PT corrections are poor approximations.

Bob.

 

[Buckethead]

Let's suppose gravitons exist, and you have a machine that is 100% effective at detecting them. If you were in a room with no windows, and there is an apparent gravitational field, then would using this machine let you tell if you were in a gravitational field or accelerating?

I'm being (somewhat) whimsical here, but a simple bathroom scale can be used to detect gravitons. If there is a reading on the scale, you have gravitons, if not, you don't. The interesting thing about this (whimsical) situation is that if the scale is accelerating, it turns out to display a reading, which would imply that acceleration generates gravitons!

 

[tom.stoer]

I think we are mixing different things:
a) are gravitons only small quantum exitations of the gravitational field?
b) or is a static field composed of gravitons?
c) if b) does acceleration generate gravitons?

I think that gravitons in the sense of a) are a very special concept that has been shown not to produce a viable theory; therefore I think b) is the rigth answer. And that means that I have to admit that c) is correct, too.

Neverthelesee, I still think we that don't agree what gravitons really are.

 

[friend]

I think we are mixing different things:
a) are gravitons only small quantum exitations of the gravitational field?
b) or is a static field composed of gravitons?
c) if b) does acceleration generate gravitons?

I think that gravitons in the sense of a) are a very special concept that has been shown not to produce a viable theory; therefore I think b) is the rigth answer. And that means that I have to admit that c) is correct, too.

Neverthelesee, I still think we that don't agree what gravitons really are.

I forgot the name of it, but there is a theory that proposes acceleration is quantized. It is used to explain dark matter, and the Pioneer annomoly. So if gravity is equivalent to acceleration, then are gravitons a form of quantized acceleration in general?

 

[tom.stoer]

Are you talking about MOND (= modified Newtonian dynamics)? It seems to explain DM, but acceleration is not quantizied, as far as I know.