Nope. If you time-reverse negative mass it doesn't act like regular mass. Time-reversed negative does fall down in a gravitational field, but it accelerates fas

Nope. If you time-reverse negative mass it doesn't act like regular mass. Time-reversed negative does fall down in a gravitational field, but it accelerates faster than positive mass does in the time-forward world. (Because positive mass slows down as it rises, while negative mass accelerates.)