THE BIG BANG THEORY is a sitcom about a group of Cal-Tech physicists who can unlock the mysteries of the universe but are too socially inept to connect with most people here on Earth. Leonard (Johnny Galecki) and Sheldon (Jim Parsons) are roommates who spend their free time with fellow scientists Howard Wolowitz (Simon Helberg) and Raj Koothrappali (Kunal Nayyar), playing board games in Klingon and watching recorded Stephen Hawking lectures. But the planets start shifting when they meet Penny (Kaley Cuoco), a pretty blonde waitress/aspiring screenwriter whos moved in next door. Even though she doesnt always appear to have a terribly high IQ or an affinity for quantum physics, Pennys looks and willingness to befriend them has the geeky guys trying their best to charm her with their limited social skills. As the series progresses, additional female characters are introduced (Sara Gilbert and Mayim Bialik) who match Leonard and Sheldons braininess.