It’s worse than just P-symmetry (parity) violation. There’s also CP-symmetry (charge-parity) breaking, which, given CPT symmetry (a fairly reasonable assumption given current knowledge) means that the weak nuclear force also violates T-symmetry. Even without the second law of thermodynamics, you would be able to put an arrow to time by observing the decay of certain particles.
It’s worse than just P-symmetry (parity) violation. There’s also CP-symmetry (charge-parity) breaking, which, given CPT symmetry (a fairly reasonable assumption given current knowledge) means that the weak nuclear force also violates T-symmetry. Even without the second law of thermodynamics, you would be able to put an arrow to time by observing the decay of certain particles.
Therefore, we need time.