If I could have a conversation with only one person in the world, my choice would be the brilliant Cambridge Professor Stephen W. Hawking, author of A Brief History of Time: From the Big Bang to Black Holes, which made astronomy undertandable to me. However, it would be difficult to speak with him, because the 68-year-old theoretical physicist has suffered from the incurable muscular disease, amyotrophic lateral sclerosis, or ALS, since 1962. The disease has confined him to a wheelchair and forced him to use a computer-generated voice synthesizer controled by one muscle in his right cheek to communicate.Diane Sawyers of ABC Evening News was fortunate enough to interview him and asked what question he most wants answered. Hawking responded, "I'd like to know why the universe exists, why there is something, not nothing." As for his beliefs, he said, "There is a fundamental difference between religion, which is based on authority, and science, which is based on observation and reason. Science will win because it works."Hawking made the controversial statement a few weeks ago that there is a good chance we are not alone in the universe, and, if extra terrestials exist, we should not assume they will be friendly. My first thought was, okay, if they look hostile, let's feed them dark chocolate - all will be well.During the ABC interview, Hawking shared the best advice he gave to his children. "Remember to look up at the stars, not down at your feet," he said. "Never give up work; it gives you meaning and purpose, and life is empty without it." And finally, "If you are lucky enough to find love, remember it's there and don't throw it away."Great advice for all of us. No wonder he is considered the most intelligent man on this planet.