Eternal the originator of time - proof.

[Alex K]

I don't understand what you mean by that (bold mine)

I mean, in QM, there are two fundamentally  different ways in which a state function can change: through continuous causal evolution and through collapse at a measurement.  Per the Heisenberg uncertainty principle, and the EPR paradox, a sister particle has its position or momentum determined by our measurement of the first, and both have no definite position AND momentum prior to it... I.e. the second is forced into one or the other when we measure for either position or momentum on the first. Of course, there's a lot of speculation about what the wave-function actually represents, but the article Robert posted isn't more drastic as a plausible solution in consideration of the problem, than something like the Everett-DeWitt interpretation.

Right. So, the Everett-DeWitt interpretation is at least one example that does not require this distinction I'd say.

The distinction between the past being fixed and remembered, the future uncertain and unknowable, may not be written into the laws of physics directly, but I have a strong suspicion that it can be understood as a statistical phenomenon even without quantum effects.