The Big Bang Theory (Season 2)

Smart is the new sexy.

Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.

The Bad Fish Paradigm 7.8
Air date: 2008-09-22
Runtime: 22 min
Overview: Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
The Codpiece Topology 7.6
Air date: 2008-09-29
Runtime: 21 min
Overview: A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
The Barbarian Sublimation 7.8
Air date: 2008-10-06
Runtime: 21 min
Overview: Sheldon creates a monster when he introduces Penny to online gaming.
The Griffin Equivalency 7.5
Air date: 2008-10-13
Runtime: 21 min
Overview: Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
The Euclid Alternative 7.5
Air date: 2008-10-20
Runtime: 20 min
Overview: Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
The Cooper-Nowitzki Theorem 7.8
Air date: 2008-11-03
Runtime: 21 min
Overview: Sheldon and the gang are confused when a young grad student is attracted to him.
The Panty Piñata Polarization 7.9
Air date: 2008-11-10
Runtime: 21 min
Overview: When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
The Lizard-Spock Expansion 7.4
Air date: 2008-11-17
Runtime: 20 min
Overview: Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
The White Asparagus Triangulation 7.4
Air date: 2008-11-24
Runtime: 21 min
Overview: Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
The Vartabedian Conundrum 7.0
Air date: 2008-12-08
Runtime: 21 min
Overview: Leonard asks Penny for advice when his new relationship starts moving too fast.
The Bath Item Gift Hypothesis 8.1
Air date: 2008-12-15
Runtime: 21 min
Overview: Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
The Killer Robot Instability 7.4
Air date: 2009-01-12
Runtime: 21 min
Overview: 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.
The Friendship Algorithm 7.5
Air date: 2009-01-19
Runtime: 21 min
Overview: Sheldon creates a scientific procedure for making friends.
The Financial Permeability 7.3
Air date: 2009-02-02
Runtime: 21 min
Overview: Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
The Maternal Capacitance 8.2
Air date: 2009-02-09
Runtime: 21 min
Overview: Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
The Cushion Saturation 7.4
Air date: 2009-03-02
Runtime: 21 min
Overview: A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
The Terminator Decoupling 7.5
Air date: 2009-03-09
Runtime: 21 min
Overview: 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.
The Work Song Nanocluster 7.5
Air date: 2009-03-16
Runtime: 20 min
Overview: Penny's home business turns into a complete nightmare when Sheldon takes over.
The Dead Hooker Juxtaposition 7.5
Air date: 2009-03-30
Runtime: 20 min
Overview: Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
The Hofstadter Isotope 7.6
Air date: 2009-04-13
Runtime: 20 min
Overview: A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.
The Vegas Renormalization 7.5
Air date: 2009-04-27
Runtime: 22 min
Overview: Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.
The Classified Materials Turbulence 7.5
Air date: 2009-05-04
Runtime: 19 min
Overview: 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.
The Monopolar Expedition 7.5
Air date: 2009-05-11
Runtime: 21 min
Overview: The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.