1 OUR PICTURE OF THE UNIVERSE ‘A wellknown scientist (some say it was Bertrand Russel) once ‘gave « public lecture on astronomy. He described how the earth ‘orbits around he sun and how the sun, in tun, orbits around the ‘center of avast collection of stats called our galaxy. Ar the end of the lecture, alte old lady atthe back of the room got up and sad: "What you have told us is rubbish, The wold is eally a flat plate supported on the back ofa giant tortoise.” The scientist gave superior smile before replying, "What isthe tortoise standing on?” ‘You're very clever, young man, very clever,” said the old lady “But i's tudes all the way down! Most people would find the picture of our universe as an infinite tower of tortoises rather ridiculous, but why do we think wwe know better? What do we know about the universe, and how do we know it? Where did the universe come from, and whe joing? Did the universe have a beginning, and i pened before then? What is the nature of time? Wil tan end? Recent breakthroughs in physics, made posible in part by fantastic new technologies, suggest answers to some of these longstanding questions. Someday these answers may sem as obyi-