> Both general relativity and quantum mechanics seem to suggest that time is not perfectly linear (GR) and not perfectly crisp or perfectly clearly delineated (

> Both general relativity and quantum mechanics seem to suggest that time is not perfectly linear (GR) and not perfectly crisp or perfectly clearly delineated (QM) Neither QM nor GR admit retrocausality. Even interactions that look time-inverted still don't let you send information back in time. I'm also not sure I agree with the idea that QM says anything is not "clearly delineated". Uncertainty relations in QM are less interesting statements than most people seem to think. It's not a matter of nature being inexact or something, it's just the fact that most physical operators don't share the same eigenstates. E.g. You wouldn't say a standing wave is "moving at x m/s" (because it's standing still), while on the other hand you wouldn't say "the wavelength of this point is k" (because points don't have wavelengths). But standing waves have wavelengths and point particles have velocities. Nothing in this description suggests to me that nature itself is inexact. It might be, but vanilla QM doesn't require it to be.