Quarks fly when ultra-geeky Caltech physicists Sheldon and Leonard (Jim Parsons and Johnny Galecki) discover that they have a new neighbor: Penny (Kaley Cuoco), a sexy actress who inspires the lads to try a relationship with something other than their particle accelerators. This science-savvy hit sitcom co-stars Simon Helberg and Kunal Nayyar as friends and fellow nerds who reveal they also have a thing or two to learn about the fairer sex.