"At this very moment, we are moving through space at 130 miles per second, and yet we don't notice at all. Nothing slips and falls off the kitchen table as the Earth spins, and our bodies aren't catapulted against random buildings and trees by the planet orbiting the Sun. We, and everything around us, move at the same rate, so we simply don't notice the force that propels us through space. Nor do we notice the strangest fact of all, that we and everything...