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Arch-nerds Leonard and Sheldon may know more than their fair share about subatomic particles, but when it comes to people in general, and women in particular, they're absolutely clueless...

About the Show

Arch-nerds Leonard and Sheldon may know more than their fair share about subatomic particles, but when it comes to people in general, and women in particular, they're absolutely clueless...

Series 2 Summary

It's been a year, and the null hypothesis - Leonard failing to get together with Penny - seems to have prevailed. But there's still hope. And if there's one thing a lifetime studying physics teaches you... it's not that.

  • Wolowitz

    Episode 1 - The Bad Fish Paradigm

    Penny opens up to a reluctant Sheldon after a less-than-stellar first date with Leonard, placing him in the uncomfortable position of having to keep a secret.

  • Leonard as a knight and Howard as a jester

    Episode 2 - The Codpiece Topology

    The Codpiece Topology: Seeing Penny out on a date with another guy sends a distressed Leonard rushing back to Leslie Winkle, much to Sheldon's dismay.

  • Penny

    Episode 3 - The Barbarian Sublimation

    Penny becomes addicted to an online game based on the world of Conan the Barbarian and persistently pesters Sheldon for advice.

  • Penny and Raj

    Episode 4 - The Griffin Equivalency

    The Griffin Equivalency: Full of confidence after being named one of People Magazine's '30 to Watch under 30', Raj hits on Penny and becomes impossibly arrogant.

  • Sheldon

    Episode 5 - The Euclid Alternative

    The Euclid Alternative: When Leonard can't drive Sheldon to and from work, the friends stage an intervention to overcome Sheldon's fear of getting behind the wheel.

  • Penny and Ramona

    Episode 6 - The Cooper-Nowitzki Theorem

    The Cooper-Nowitzki Theorem: Sheldon's friends are mystified when a younger student is attracted to him, but her intense devotion soon becomes too much.

  • Penny

    Episode 7 - The Panty PiƱata Polarization

    After Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate. Her plan involves a telephone, and Sheldon's mother.

  • Leonard and Stephanie

    Episode 8 - The Lizard-Spock Expansion

    A girl Wolowitz has a major crush on falls for Leonard, despite Wolowitz's elaborate attempts to woo her - including an abortive joyride on the Mars Rover.

  • Stephanie and Leonard

    Episode 9 - The White Asparagus Triangulation

    The White Asparagus Triangulation: Sheldon is delighted that Leonard finally has a girlfriend matching his high standards... perhaps a little too delighted.

  • Sheldon and Stephanie

    Episode 10 - The Vartabedian Conundrum

    The Vartabedian Conundrum: Leonard goes to Penny for help when his relationship with Stephanie takes off faster than he'd like, but will he choose to act on her advice?

  • Leonard and Dr Underhill

    Episode 11 - The Bath Item Gift Hypothesis

    The Bath Item Gift Hypothesis: At Christmas, Leonard's handsome colleague starts dating Penny, while Sheldon's obsession with gift-giving etiquette torments his friends.

  • The boys and their robot

    Episode 12 - The Killer Robot Instability

    The Killer Robot Instability: Kripke challenges the boys to a robot duel, while Howard is hurt when Penny reveals what she thinks about his behaviour towards women.

  • Sheldon and Barry Kripke

    Episode 13 - The Friendship Algorithm

    The Friendship Algorithm: Sheldon develops a scientific procedure for making friends when he discovers that Kripke has control of a new supercomputer at the university.

  • Penny and Sheldon listen through the door

    Episode 14 - The Financial Permeability

    The Financial Permeability: When Sheldon lends Penny some money, it brings her ex-boyfriend Kurt back into her life, with negative consequences for the gang.

  • Beverly and Leonard

    Episode 15 - The Maternal Capacitance

    The Maternal Capacitance: A disastrous visit from Leonard's mother Beverly has the unexpected side-effect of bringing Leonard and Penny closer together.

  • Raj

    Episode 16 - The Cushion Saturation

    The Cushion Saturation: A game of paintball leads to a squabble when Penny accidentally shoots paint at one of Sheldon's cushions. Romance blossoms between Howard and Leslie.

  • Howard and Summer Glau

    Episode 17 - The Terminator Decoupling

    The Terminator Decoupling: Leonard, Sheldon, Howard and Raj discover that beautiful sci-fi actress Summer Glau is on board their train to San Francisco.

  • Penny with a 'Pennyblossom' in her hair

    Episode 18 - The Work Song Nanocluster

    Penny's home-based business selling hair barrettes - her 'Pennyblossoms' - gets out of hand when a caffeine-high Sheldon takes charge.

  • Penny and Alicia

    Episode 19 - The Dead Hooker Juxtaposition

    Penny develops a rivalry with sexy new female neighbour Alicia - who threatens to steal the boys' attention and become the 'new Penny'.

  • Penny and Stuart

    Episode 20 - The Hofstadter Isotope

    The Hofstadter Isotope: Leonard is devastated when Stuart from the comic book shop chats Penny up. Even worse, she doesn't mind, so Sheldon tries to scupper the budding romance.

  • 'Esther' and Howard

    Episode 21 - The Vegas Renormalisation

    Leonard and Raj take a heartbroken Howard to Las Vegas, home of slots, shrimp, and high-class hookers. Sheldon, meanwhile, is locked out of his apartment and forced to bunk with Penny.

  • Sheldon

    Episode 22 - The Classified Materials Turbulence

    The Classified Materials Turbulence: Things begin to look up for Leonard when Penny makes a surprising revelation on her second date with Stuart.

  • Leonard and Penny embracing

    Episode 23 - The Monopolar Expedition

    Leonard and Penny reconsider their feelings for each other, but then Leonard decides to spend the summer working at the North Pole - on a mission led by Sheldon.

The Big Bang Theory synopsis

Arch-nerds Leonard and Sheldon may know more than their fair share about subatomic particles, but when it comes to people in general, and women in particular, they're absolutely clueless...

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