Physics is nearly time-symmetric,
yet time has a direction. Where does
that asymmetry come from, why does it
trace to initial conditions rather
than dynamics, and what remains
unexplained?

Why Time Has a Direction

The asymmetry traced to initial conditions, and what's left over.

Prompt

The laws of physics are almost all time-symmetric, yet time clearly has a direction. Explain where that asymmetry comes from, why it traces back to initial conditions rather than dynamics, and what remains genuinely unexplained.