Abstract

We consider several thought and practical experiments, and variations thereof, from which the existence can be inferred of retroactive effects on the assumptions of conservation of linear and angular momentum and of realism defined in a wide sense. Such conclusion is made less counterintuitive by research into the proper physical background of the relativistic length contraction of a moving arrow, viz. the fact that the universe is four-dimensional indeed. In one of the experiments considered, the evidence of retroactivity is more striking and can more easily be actually demonstrated than was the case in earlier proofs