In today's physical review X , Jonathan Oppenheim presented a paper where he claims to have united general relativity and quantum mechanics, he doesn't change general relativity at all but he does add an additional probabilistic element to quantum mechanics . He says his theory doesn't have any internal inconsistencies but determining if it's true will require future experiments to see if spacetime is continuous or discrete, Oppenheim thinks it's continuous and thus General Relativity needs no modification, but quantum mechanics does.
*Abstract: * By Jonathan Oppenheim "*The effort to discover a quantum theory of gravity is motivated by the need to reconcile the incompatibility between quantum theory and general relativity. Here, we present an alternative approach by constructing a consistent theory of classical gravity coupled to quantum field theory. The dynamics is linear in the density matrix, completely positive and trace preserving, and reduces to Einstein’s theory of general relativity in the classical limit. Consequently, the dynamics doesn’t suffer from the pathologies of the semiclassical theory based on expectation values. The assumption that general relativity is classical necessarily modifies the dynamical laws of quantum mechanics – the theory must be fundamentally stochastic in both the metric degrees of freedom and in the quantum matter fields. This allows it to evade several no-go theorems purporting to forbid classical-quantum interactions. The measurement postulate of quantum mechanics is not needed – the interaction of the quantum degrees of freedom with classical space-time necessarily causes decoherence in the quantum system. We first derive the general form of classical-quantum dynamics and consider realisations which have as its limit deterministic classical Hamiltonian evolution. The formalism is then applied to quantum field theory interacting with the classical space-time metric. One can view the classical-quantum theory as fundamental or as an effective theory useful for computing the back-reaction of quantum fields on geometry. We discuss a number of open questions from the perspective of both viewpoints.* *A postquantum theory of classical gravity? <https://arxiv.org/pdf/1811.03116.pdf>* John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis> qmd -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAJPayv28CNQ20QsN2OGsjkz7LuN_ZfA9zhCSw8xTHE8%2BpDRTAA%40mail.gmail.com.
