Now he has departed from this strange world a little ahead of me. That means nothing. People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion.

            --Albert Einstein (1879-1955) in a letter of condolence to the sister of an old friend, March 1955. Quoted in Disturbing the Universe (1979), Freeman Dyson, p. 193