I've been discussing Lorentzian and Einsteinian relativity here on PF, as well learning about them elsewhere, and a question occurred to me, and I thought that this might be the place to post it. The problem of time, as I understand it, is based on the fact that quantum mechanics and Einsteinian relativity use different concepts of time; I've read that QM uses "a more Newtonian" concept. I'm just wondering if this issue would be the same under Lorentzian relativity, which also seems to incorporate a more Newtonian concept of time? Given that both Lorentzian and Einsteinian relativity are not distinguished by means of experimental evidence, would it be possible to unify QM with Lorentzian relativity; are there any such attempts? EDIT: I was going to add a point on the Wheeler-DeWitt equation, but I didn't think it was relevant, but if my understanding, that the mathematics of Einsteinian and Lorentzian relativity are the same, then perhaps it might be relevant. My basic understanding if the Wheeler-DeWitt equation is that time does not appear in it, suggesting that the universe is timeless; while Lorentzian relativity includes the notion of absolute time, it is a short distance from the notion of absolute time to timelessness.