The Big Bang Theory - Season 2
1 - The Bad Fish Paradigm
Air Date: September 22, 2008
Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
2 - The Codpiece Topology
Air Date: September 29, 2008
A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
3 - The Barbarian Sublimation
Air Date: October 6, 2008
Sheldon creates a monster when he introduces Penny to online gaming.
4 - The Griffin Equivalency
Air Date: October 13, 2008
Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
5 - The Euclid Alternative
Air Date: October 20, 2008
Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
6 - The Cooper-Nowitzki Theorem
Air Date: November 3, 2008
Sheldon and the gang are confused when a young grad student is attracted to him.
7 - The Panty Piñata Polarization
Air Date: November 10, 2008
When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
8 - The Lizard-Spock Expansion
Air Date: November 17, 2008
Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
9 - The White Asparagus Triangulation
Air Date: November 24, 2008
Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
10 - The Vartabedian Conundrum
Air Date: December 8, 2008
Leonard asks Penny for advice when his new relationship starts moving too fast.
11 - The Bath Item Gift Hypothesis
Air Date: December 15, 2008
Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
12 - The Killer Robot Instability
Air Date: January 12, 2009
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.
13 - The Friendship Algorithm
Air Date: January 19, 2009
Sheldon creates a scientific procedure for making friends.
14 - The Financial Permeability
Air Date: February 2, 2009
Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
15 - The Maternal Capacitance
Air Date: February 9, 2009
Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
16 - The Cushion Saturation
Air Date: March 2, 2009
A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
17 - The Terminator Decoupling
Air Date: March 9, 2009
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.
18 - The Work Song Nanocluster
Air Date: March 16, 2009
Penny's home business turns into a complete nightmare when Sheldon takes over.
19 - The Dead Hooker Juxtaposition
Air Date: March 30, 2009
Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
20 - The Hofstadter Isotope
Air Date: April 13, 2009
A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.
21 - The Vegas Renormalization
Air Date: April 27, 2009
Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.
22 - The Classified Materials Turbulence
Air Date: May 4, 2009
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.
23 - The Monopolar Expedition
Air Date: May 11, 2009
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.