I did not come from an academic background. My father was a smart man, but he had a fifth-grade education. He and all his friends were plumbers. They were all born around 1905 in great poverty in New York City and had to go to work when they were 12 or 13 years old.
Leonard SusskindThere is a philosophy that says that if something is unobservable -- unobservable in principle -- it is not part of science. If there is no way to falsify or confirm a hypothesis, it belongs to the realm of metaphysical speculation, together with astrology and spiritualism. By that standard, most of the universe has no scientific reality -- it's just a figment of our imaginations.
Leonard Susskind