Acceleration & Quantum Gravity: A Fundamental Disconnect?

[grelf]

General relativity is all about acceleration (equivalence principle).

Quantum theory never mentions acceleration. New object speeds and directions only arise from discrete interaction events.

Is this the fundamental reason why the two theories are so hard to reconcile?

 

[toombs]

I don't think one could point to just one particular problem with reconciling the two theories, but if I had to, then I'd say the biggest problem is the stress-energy tensor in the Einstein field equations. It determines how spacetime is curved, but it is determined by macroscopic properties like mass density, mass flux density, and pressure. These quantities break down completely on the atomic scale and the tidy picture of stress-energy deterministically curving spacetime falls apart.