Stephen William Hawking is arguably the most famous scientist since Albert Einstein. He is a theoretical physicist, applied mathematician, and cosmologist, but he is best known to non-scientists as the author of 'A Brief History of Time,' his best-selling book that unraveled the origins of the universe. His fame is so far-reaching that he has appeared on such popular entertainment as 'Star Trek: The Next Generation' and 'Late Night with Conan O'Brien.' He has even been animated as a character on 'The Simpsons.' Hawking is also well known for being the longest-living survivor of amyotrophic lateral sclerosis (ALS, or 'Lou Gehrig's disease'). Most patients can expect to live for no more than ten years following a diagnosis of ALS, but Hawking has survived for almost 50 years since the onset of the disease. The condition has caused him almost total paralysis, confining him to a wheelchair and forcing him to speak through a voice synthesizer activated by his cheek muscle.