Quantum theory lives in abstract, complex, linear Hilbert space, is unitary and non-dissipative, and has been shown not to be embeddable in spacetime for N > 2quantum entities. It is per definition unobservable (in itself). Classical physics describes the causal, nonlinear dynamics of actual events, which lie in, and also define, four-dimensional spacetime. The "Born Rule" connects abstract quantum theory with real events in classical spacetime. It is postulated separately and cannot be deduced from quantum theory, as it is both non-unitary and irreversible, i.e. dissipative. Separating and treating it correctly in this manner resolves a number of fundamental problems of gravitation vs. quantum theory, such as the black hole information paradox,the cosmological constant problem and quantization of general relativity.