After Albert Einstein, Stephen Hawking is probably the most famous physicist of all time. But most of us are probably more familiar with his disability (and his amazing ability to overcome it) than we are with his actual theorems. He's been in a wheelchair for 40 years and unable to speak since 1985, but he's still trying to find the key to the universe. Kinda makes you feel a little lazy, doesn't it? So, how much do you know about Stephen Hawking?