> Bohm's interpretation is 100% mathematically equivalent to the standard interpretation, making it observationally impossible to distinguish the two This is

> Bohm's interpretation is 100% mathematically equivalent to the standard interpretation, making it observationally impossible to distinguish the two This is not quite correct. It is mathematically equivalent to Copenhagen only at times of 'quantum equilibrium', which is when ρ = φ² (probability density is the square of the wavefunction). Copenhagenists call this the Born rule and treat it as axiomatic. Bohmians don't since they don't need to, since in Bohmian mechanics a system which is not in quantum equilibrium will evolve to be in quantum equilibrium in a very very short time. Which gives a way to empirically distinguish pilot-wave theory if the universe began in quantum non-equilibrium. (We have no reason to think it did, but we have no reason to think it didn't, so, shrug). If it did, the early universe would have evolved differently in the first femtosecond after the big bang, which should theoretically be detectable to us by analysis of CMB anisotropies. This has been worked on: a friend of mine did a masters project which among other things involved porting some simulation code on very-early-universe numeric simulations under quantum non-equilibrium (IIRC from fortran 77 to fortran 95, because physicists), under Mike Towler.