1. The Bad Fish Paradigm
Aired Sep 23, 2008 · 22 minutes
Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
2. The Codpiece Topology
Aired Sep 30, 2008 · 21 minutes
A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
3. The Barbarian Sublimation
Aired Oct 7, 2008 · 21 minutes
Sheldon creates a monster when he introduces Penny to online gaming.
4. The Griffin Equivalency
Aired Oct 14, 2008 · 21 minutes
Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
5. The Euclid Alternative
Aired Oct 21, 2008 · 20 minutes
Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
6. The Cooper-Nowitzki Theorem
Aired Nov 4, 2008 · 21 minutes
Sheldon and the gang are confused when a young grad student is attracted to him.
7. The Panty Piñata Polarization
Aired Nov 11, 2008 · 21 minutes
When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
8. The Lizard-Spock Expansion
Aired Nov 18, 2008 · 20 minutes
Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
9. The White Asparagus Triangulation
Aired Nov 25, 2008 · 21 minutes
Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
10. The Vartabedian Conundrum
Aired Dec 9, 2008 · 21 minutes
Leonard asks Penny for advice when his new relationship starts moving too fast.
11. The Bath Item Gift Hypothesis
Aired Dec 16, 2008 · 21 minutes
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
Aired Jan 13, 2009 · 21 minutes
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
Aired Jan 20, 2009 · 21 minutes
Sheldon creates a scientific procedure for making friends.
14. The Financial Permeability
Aired Feb 3, 2009 · 21 minutes
Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
15. The Maternal Capacitance
Aired Feb 10, 2009 · 21 minutes
Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
16. The Cushion Saturation
Aired Mar 3, 2009 · 21 minutes
A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
17. The Terminator Decoupling
Aired Mar 10, 2009 · 21 minutes
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
Aired Mar 17, 2009 · 20 minutes
Penny's home business turns into a complete nightmare when Sheldon takes over.
19. The Dead Hooker Juxtaposition
Aired Mar 31, 2009 · 20 minutes
Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
20. The Hofstadter Isotope
Aired Apr 14, 2009 · 20 minutes
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
Aired Apr 28, 2009 · 22 minutes
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
Aired May 5, 2009 · 19 minutes
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
Aired May 12, 2009 · 21 minutes
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.