The "Big Bang Theory" centers on four geeks who work at Caltech University. Leonard Hofstadter is an experimental physicist who has an on-and-off-again romance with his neighbor Penny who is a waitress at the Cheesecake Factory. Compared to the other characters on the show, Penny is streetwise. Leonard shares an apartment with Sheldon Cooper who has an eidetic memory and is a theoretical physicist. Sheldon is a quirky character known for his need for routine and awkwardness in social situations. Both petty and childlike, he begins an intellectual-romantic relationship with Amy Farrah Fowler. Howard Wolowitz works as an aerospace engineer and is much controlled by his Jewish mother. Later in the season, he marries Bernadette Rostenkowski and evolves from an unsuccessful pick-up guy to a humorous married man. Raj Ramayan works as a particle astrophysicist at Caltech and can't speak to women unless he has alcohol. He's best buds with Howard and often leans on him for support on how to land a woman.