Season 2
23 episodes · first aired 2008-09-22
| Still | # | Title | Overview | Air date | Rating |
|---|---|---|---|---|---|
 | 01 | The Bad Fish Paradigm 2008-09-22 | Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant. | 2008-09-22 | 8.2 |
 | 02 | The Codpiece Topology 2008-09-29 | A jealous Leonard reacts to Penny's new guy by rebounding with Leslie. | 2008-09-29 | 8.0 |
 | 03 | The Barbarian Sublimation 2008-10-06 | Sheldon creates a monster when he introduces Penny to online gaming. | 2008-10-06 | 8.7 |
 | 04 | The Griffin Equivalency 2008-10-13 | Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article. | 2008-10-13 | 7.9 |
 | 05 | The Euclid Alternative 2008-10-20 | Leonard and his friends stage an intervention to force Sheldon to face his fear of driving. | 2008-10-20 | 8.3 |
 | 06 | The Cooper-Nowitzki Theorem 2008-11-03 | Sheldon and the gang are confused when a young grad student is attracted to him. | 2008-11-03 | 8.2 |
 | 07 | The Panty Piñata Polarization 2008-11-10 | When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate. | 2008-11-10 | 8.6 |
 | 08 | The Lizard-Spock Expansion 2008-11-17 | Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life. | 2008-11-17 | 8.0 |
 | 09 | The White Asparagus Triangulation 2008-11-24 | Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards. | 2008-11-24 | 8.1 |
 | 10 | The Vartabedian Conundrum 2008-12-08 | Leonard asks Penny for advice when his new relationship starts moving too fast. | 2008-12-08 | 7.6 |
 | 11 | The Bath Item Gift Hypothesis 2008-12-15 | Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette. | 2008-12-15 | 9.1 |
 | 12 | The Killer Robot Instability 2009-01-12 | Penny's criticism of Wolowitz's romantic life pushes him into depression and AWOL for a fighting robot battle the rest of guys are depending on him for. | 2009-01-12 | 7.6 |
 | 13 | The Friendship Algorithm 2009-01-19 | Sheldon creates a scientific procedure for making friends. | 2009-01-19 | 7.9 |
 | 14 | The Financial Permeability 2009-02-02 | Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend. | 2009-02-02 | 8.0 |
 | 15 | The Maternal Capacitance 2009-02-09 | Leonard and Penny are drawn together after a disastrous visit from Leonard's mother. | 2009-02-09 | 8.8 |
 | 16 | The Cushion Saturation 2009-03-02 | A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz. | 2009-03-02 | 8.1 |
 | 17 | The Terminator Decoupling 2009-03-09 | Leonard, Sheldon and Wolowitz are ecstatic to learn that a famous science-fiction actress (Summer Glau) is on board the train they are taking to San Francisco. | 2009-03-09 | 8.0 |
 | 18 | The Work Song Nanocluster 2009-03-16 | Penny's home business turns into a complete nightmare when Sheldon takes over. | 2009-03-16 | 8.1 |
 | 19 | The Dead Hooker Juxtaposition 2009-03-30 | Penny squares off with a new beautiful female neighbor who may become the building's "new Penny." | 2009-03-30 | 8.1 |
 | 20 | The Hofstadter Isotope 2009-04-13 | A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night. | 2009-04-13 | 7.9 |
 | 21 | The Vegas Renormalization 2009-04-27 | Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny. | 2009-04-27 | 8.5 |
 | 22 | The Classified Materials Turbulence 2009-05-04 | Penny's second date with Stuart sees her making a comment that gives Leonard new hope for a relationship with her. Wolowitz realizes there's a crucial error in a NASA project he's working on. | 2009-05-04 | 8.1 |
 | 23 | The Monopolar Expedition 2009-05-11 | The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard. | 2009-05-11 | 8.2 |
Ratings shown are community scores. Once OMDB is wired, these become per-episode IMDB values.