- S02e20: Watch Www Xrysoi Se The Big Bang Theory

"The Hofstadter Isotope" (Season 2, Episode 20), originally aired on April 13, 2009, features the introduction of comic book store owner Stuart Bloom, who asks Penny out on a date. While the guys head to a bar for "ladies' night," the episode highlights the contrast between the main characters and typical social scenarios. Stream the episode on Max . The Hofstadter Isotope