Listen: We began with the mystery of how ancient peoples had erected the pyramids of Egypt and Mexico, and the great heads of Easter Island, and the barbaric arches of Stonehenge, without modern power sources and tools. We concluded there must have been days of light gravity in olden times, when people could play tiddledy winks with huge chunks of stone. We supposed that it might even be abnormal on earth for gravity to be stable for long periods of time. We predicted that at any moment gravity might become as capricious as winds and heat and cold, as blizzards and rainstorms again.
