Chimpanzees have immense arm strength - far beyond the strongest body builders, so you might think a chimp with a rock is pretty dangerous. Only if they can hit you. They don't have control, and their aim is lousy. One of the things evolution seems to have devoted a lot of effort to in humans is developing our pitching skills. this strongly suggests that the development of missile weapons played a key part in making us human.
Time crystals would be a perpetuum mobile
3 hours ago