When my son Mario was at the age when youngsters are a fountain of questions, he began one of his inquisitorial series, this time on the nature of electricity. He asked, and I did my best to explain, why one notices no change in wires when they are connected to the outlet, where the electricity comes from, and then what is the source of energy. My answers in technical matters would never be distinguished by profundity, but I told him of dynamos, transforming the energy of fuels or waterfalls into electricity, and of the unharnessed energy of our sun and the millions of suns in the universe. He finally asked, "And where have these millions of stars obtained their energy?"