Oersted, Hans Christian (1777-1851), a Danish physicist and chemist. His investigations laid the foundation for the science of electromagnetism. In 1820 Oersted observed that a magnetic needle could be deflected by an electric current. This led him to conclude that there was a fundamental relationship between electricity and magnetism. In 1825 he was the first to isolate aluminum (in an impure form). He taught at the University of Copenhagen, 1806-29. He became the first director of the Polytekniske Laereanstalt (the Danish technical institute) in 1829.
He's ventured to the abyss of black holes, wagered on the information paradox and floated around in zero gravity. Meet the man, the legend, the super scientist: Stephen Hawking.
He is famous for a phrase he never said, for wearing turtlenecks and for hosting the original 'Cosmos' TV series. As enthusiastic about the stars as he was about marijuana, Carl Sagan led a very surprising life. Here are 10 cool facts.