Hello! I know nowadays physicists try to make the grate unification - all 4 forces in a single theory that would govern all of their interactions :) However many people say QM and GR are incompatible. Can anyone of you please explain to me why this is so? I know that QM is a probability theory, whereas GR is a deterministic one, but after all - both of them include our reality as a separate 'boundary' case, don't they? Then what splits them up and makes them so different to be even incompatible (at least for now)?