Episodes
The Bad Fish Paradigm
7.8Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.
22 min
The Codpiece Topology
7.5A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.
21 min
The Barbarian Sublimation
7.8Sheldon creates a monster when he introduces Penny to online gaming.
21 min
The Griffin Equivalency
7.5Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.
21 min
The Euclid Alternative
7.5Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.
20 min
The Cooper-Nowitzki Theorem
7.8Sheldon and the gang are confused when a young grad student is attracted to him.
21 min
The Panty Piñata Polarization
7.9When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.
21 min
The Lizard-Spock Expansion
7.4Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.
20 min
The White Asparagus Triangulation
7.3Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.
21 min
The Vartabedian Conundrum
6.9Leonard asks Penny for advice when his new relationship starts moving too fast.
21 min
The Bath Item Gift Hypothesis
8.2Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.
21 min
The Killer Robot Instability
7.5Penny'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.
21 min
The Friendship Algorithm
7.5Sheldon creates a scientific procedure for making friends.
21 min
The Financial Permeability
7.4Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.
21 min
The Maternal Capacitance
8.2Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.
21 min
The Cushion Saturation
7.5A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.
21 min
The Terminator Decoupling
7.5Leonard, 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.
21 min
The Work Song Nanocluster
7.6Penny's home business turns into a complete nightmare when Sheldon takes over.
20 min
The Dead Hooker Juxtaposition
7.6Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."
20 min
The Hofstadter Isotope
7.6A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.
20 min
The Vegas Renormalization
7.4Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.
22 min
The Classified Materials Turbulence
7.4Penny'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.
19 min
The Monopolar Expedition
7.4The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.
21 min