The Veracity Elasticity: Leonard is upset when he finds out that Penny has been moving his collectables out of Sheldon's old room and into storage behind his back. (S10 Ep7/24) [AD,S]
The Brain Bowl Incubation: Sheldon tries to convince Amy that they should procreate. Raj feels embarrassed about what the new woman in his life does for a living. (S10 Ep8/24) [AD,S]
The Fortification Implementation: When Sheldon and Amy build a blanket fort, they come to a major crossroads in their relationship. Howard meets his half-brother. (S8 Ep20/24) [AD,S]
The Communication Deterioration: Raj is asked to create a message for NASA to use if one of their missions finds alien life. Penny considers taking up acting again. (S8 Ep21/24) [AD,S]
The Graduation Transmission: Leonard is invited to make a speech at his old high school. Howard and Sheldon can't make a toy drone fly. (S8 Ep22/24) [AD,S]
The Maternal Combustion: Personalities collide when Sheldon and Leonard's mothers finally meet. Howard decides to 'man up' and do his share of the housework. (S8 Ep23/24) [AD,S]
The Positive Negative Reaction: When Bernadette makes a big announcement, Howard becomes convinced that he needs to start earning more money. (S9 Ep16/24) [AD,S]
The Celebration Experimentation: The gang persuade Sheldon to celebrate his birthday and invite a few special guests along to his party, in the 200th episode. (S9 Ep17/24) [AD,S]
The Commitment Determination: Sheldon pressures Leonard and Penny to choose a date for their wedding while dealing with changes in his own relationship. (S8 Ep24/24) [AD,S]
The Matrimonial Momentum: Penny struggles with Leonard's confession that he kissed another woman. Sheldon doesn't know how to act when Amy breaks up with him. (S9 Ep1/24) [AD,S]
The Separation Oscillation: Sheldon films a special post-break-up episode of Fun with Flags. Bernadette feels guilty about withholding a secret from Penny. (S9 Ep2/24) [AD,S]
The Bachelor Party Corrosion: The guys' science skills are tested when they get a flat tyre during Leonard's surprise bachelor party weekend in Mexico. (S9 Ep3/24) [AD,S]
The Holiday Summation: After spending Christmas apart, the gang gather at Penny and Leonard's flat and hear about Sheldon and Amy's terrible trip to Texas. (S10 Ep12/24) [AD,S]
The Romance Recalibration: Penny thinks that Leonard has stopped making an effort in their relationship, so she decides to go away for a spa weekend with Amy. (S10 Ep13/24) [AD,S]
The 2003 Approximation: Sheldon sulks when Penny and Leonard announce that they're moving in together. Howard and Raj form a band to play at the comic book shop. (S9 Ep4/24) [AD,S]
The Perspiration Implementation: The guys take fencing lessons from Barry Kripke. Stuart struggles to attract female customers to the comic book shop. (S9 Ep5/24) [AD,S]
The Helium Insufficiency: Sheldon and Leonard struggle to find the supplies they need for an experiment. Penny and Bernadette download a dating app for Amy. (S9 Ep6/24) [AD,S]
The 2003 Approximation: Sheldon sulks when Penny and Leonard announce that they're moving in together. Howard and Raj form a band to play at the comic book shop. (S9 Ep4/24) [AD,S]
The Spock Resonance: While he's being interviewed for a documentary about Star Trek character Mr Spock, Sheldon can't suppress his emotions about his split from Amy. (S9 Ep7/24) [AD,S]
The Perspiration Implementation: The guys take fencing lessons from Barry Kripke. Stuart struggles to attract female customers to the comic book shop. (S9 Ep5/24) [AD,S]
The Helium Insufficiency: Sheldon and Leonard struggle to find the supplies they need for an experiment. Penny and Bernadette download a dating app for Amy. (S9 Ep6/24) [AD,S]
The Spock Resonance: While he's being interviewed for a documentary about Star Trek character Mr Spock, Sheldon can't suppress his emotions about his split from Amy. (S9 Ep7/24) [AD,S]
The Convergence Convergence: Conflict arises when Leonard's recently divorced parents and Sheldon's devoutly religious mother are all in town at the same time. (S9 Ep24/24) [AD,S]
The Conjugal Conjecture: The gang face an awkward morning after Sheldon's mother and Leonard's father share an evening together. Penny's family arrive in town. (S10 Ep1/24) [AD,S]
The Military Miniaturization: Howard has a meeting with Air Force representative Colonel Williams about the gyroscope he invented with Leonard and Sheldon. (S10 Ep2/24) [AD,S]
The Convergence Convergence: Conflict arises when Leonard's recently divorced parents and Sheldon's devoutly religious mother are all in town at the same time. (S9 Ep24/24) [AD,S]
The Dependence Transcendence: Tensions rise when the guys struggle to complete their Air Force project on time and are forced to work around the clock. (S10 Ep3/24) [AD,S]
The Conjugal Conjecture: The gang face an awkward morning after Sheldon's mother and Leonard's father share an evening together. Penny's family arrive in town. (S10 Ep1/24) [AD,S]
The Military Miniaturization: Howard has a meeting with Air Force representative Colonel Williams about the gyroscope he invented with Leonard and Sheldon. (S10 Ep2/24) [AD,S]
The Dependence Transcendence: Tensions rise when the guys struggle to complete their Air Force project on time and are forced to work around the clock. (S10 Ep3/24) [AD,S]
The Emotion Detection Automation: Sheldon tests a new invention after hearing that it could help him to read people's emotions. Raj seeks dating advice. (S10 Ep14/24) [AD,S]
The Locomotion Reverberation: Leonard and Howard distract Sheldon with a trip to a historic railway when he slows their progress on the guidance system. (S10 Ep15/24) [AD,S]
The Emotion Detection Automation: Sheldon tests a new invention after hearing that it could help him to read people's emotions. Raj seeks dating advice. (S10 Ep14/24) [AD,S]
The Locomotion Reverberation: Leonard and Howard distract Sheldon with a trip to a historic railway when he slows their progress on the guidance system. (S10 Ep15/24) [AD,S]
The Mystery Date Observation: While Amy's out on a date with a mystery man, Sheldon enlists Howard and Raj to help him find a new girlfriend online. (S9 Ep8/24) [AD,S]
The Platonic Permutation: At Thanksgiving, Sheldon and Amy hang out as friends at the aquarium, and Howard reluctantly agrees to volunteer at a soup kitchen. (S9 Ep9/24) [AD,S]
The Earworm Reverberation: Sheldon is driven to distraction when he can't get a familiar tune out of his head. Howard and Raj find out that their band has a fan. (S9 Ep10/24) [AD,S]
The Mystery Date Observation: While Amy's out on a date with a mystery man, Sheldon enlists Howard and Raj to help him find a new girlfriend online. (S9 Ep8/24) [AD,S]
The Opening Night Excitation: Leonard, Howard and Raj have an extra ticket for the Star Wars movie premiere but can't decide who they should give it to. (S9 Ep11/24) [AD,S]
The Platonic Permutation: At Thanksgiving, Sheldon and Amy hang out as friends at the aquarium, and Howard reluctantly agrees to volunteer at a soup kitchen. (S9 Ep9/24) [AD,S]
The Earworm Reverberation: Sheldon is driven to distraction when he can't get a familiar tune out of his head. Howard and Raj find out that their band has a fan. (S9 Ep10/24) [AD,S]
The Opening Night Excitation: Leonard, Howard and Raj have an extra ticket for the Star Wars movie premiere but can't decide who they should give it to. (S9 Ep11/24) [AD,S]
The Cohabitation Experimentation: When Amy's flat is flooded, she has to move out while it is being repaired and proposes a 'cohabitation experiment' with Sheldon. (S10 Ep4/24) [AD,S]
The Hot Tub Contamination: Leonard and Penny intervene when Sheldon and Amy have an argument. Howard and Bernadette are disturbed by unexpected guests. (S10 Ep5/24) [AD,S]
The Fetal Kick Catalyst: Penny meets her fans at a comic book convention. Sheldon and Amy host brunch at Penny's flat. Howard makes an impulsive purchase. (S10 Ep6/24) [AD,S]
The Cohabitation Experimentation: When Amy's flat is flooded, she has to move out while it is being repaired and proposes a 'cohabitation experiment' with Sheldon. (S10 Ep4/24) [AD,S]
The Veracity Elasticity: Leonard is upset when he finds out that Penny has been moving his collectables out of Sheldon's old room and into storage behind his back. (S10 Ep7/24) [AD,S]
The Hot Tub Contamination: Leonard and Penny intervene when Sheldon and Amy have an argument. Howard and Bernadette are disturbed by unexpected guests. (S10 Ep5/24) [AD,S]
The Fetal Kick Catalyst: Penny meets her fans at a comic book convention. Sheldon and Amy host brunch at Penny's flat. Howard makes an impulsive purchase. (S10 Ep6/24) [AD,S]
The Veracity Elasticity: Leonard is upset when he finds out that Penny has been moving his collectables out of Sheldon's old room and into storage behind his back. (S10 Ep7/24) [AD,S]
The Allowance Evaporation: Amy is furious when she learns that Sheldon has shared intimate details of their relationship with his colleagues. (S10 Ep16/24) [AD,S]
The Comic-Con Conundrum: Cut off from his father's fortune, Raj appoints Sheldon to organise his finances. Penny considers joining the guys at Comic-Con. (S10 Ep17/24) [AD,S]
The Allowance Evaporation: Amy is furious when she learns that Sheldon has shared intimate details of their relationship with his colleagues. (S10 Ep16/24) [AD,S]
The Comic-Con Conundrum: Cut off from his father's fortune, Raj appoints Sheldon to organise his finances. Penny considers joining the guys at Comic-Con. (S10 Ep17/24) [AD,S]
The Sales Call Sublimation: Penny gets more than she bargained for when Leonard meets a psychiatrist, while Sheldon and Raj make an astronomical discovery. (S9 Ep12/24) [AD,S]
The Empathy Optimization: The gang plan a Sheldon-free weekend in Las Vegas after coping with his constant demands, rudeness and ingratitude when he was ill. (S9 Ep13/24) [AD,S]
The Meemaw Materialization: Sheldon is thrilled when his beloved grandmother 'Meemaw' comes to visit, but his excitement fades when she butts heads with Amy. (S9 Ep14/24) [AD,S]
The Sales Call Sublimation: Penny gets more than she bargained for when Leonard meets a psychiatrist, while Sheldon and Raj make an astronomical discovery. (S9 Ep12/24) [AD,S]
The Valentino Submergence: Sheldon and Amy host a special live Valentine's Day episode of their internet show Fun with Flags. Leonard and Penny grapple with getting older. (S9 Ep15/24) [AD,S]
The Empathy Optimization: The gang plan a Sheldon-free weekend in Las Vegas after coping with his constant demands, rudeness and ingratitude when he was ill. (S9 Ep13/24) [AD,S]
The Meemaw Materialization: Sheldon is thrilled when his beloved grandmother 'Meemaw' comes to visit, but his excitement fades when she butts heads with Amy. (S9 Ep14/24) [AD,S]
The Valentino Submergence: Sheldon and Amy host a special live Valentine's Day episode of their internet show Fun with Flags. Leonard and Penny grapple with getting older. (S9 Ep15/24) [AD,S]
The Brain Bowl Incubation: Sheldon tries to convince Amy that they should procreate. Raj feels embarrassed about what the new woman in his life does for a living. (S10 Ep8/24) [AD,S]
The Geology Elevation: Sheldon can't contain his jealousy when he hears that his university colleague, Bert the geologist, has won a prestigious fellowship. (S10 Ep9/24) [AD,S]
The Brain Bowl Incubation: Sheldon tries to convince Amy that they should procreate. Raj feels embarrassed about what the new woman in his life does for a living. (S10 Ep8/24) [AD,S]
The Birthday Synchronicity: Sheldon and Amy try to celebrate her birthday with an intimate night at home but are interrupted when Bernadette goes into labour. (S10 Ep11/24) [AD,S]
The Geology Elevation: Sheldon can't contain his jealousy when he hears that his university colleague, Bert the geologist, has won a prestigious fellowship. (S10 Ep9/24) [AD,S]
The Birthday Synchronicity: Sheldon and Amy try to celebrate her birthday with an intimate night at home but are interrupted when Bernadette goes into labour. (S10 Ep11/24) [AD,S]
The Escape Hatch Identification: Leonard and Penny offer Sheldon's old room to Raj when he's forced to move out of his flat, leading to unexpected conflict. (S10 Ep18/24) [AD,S]
The Collaboration Fluctuation: Leonard, Penny and Raj settle into their new living arrangement, and Sheldon expresses an interest in Amy's professional life. (S10 Ep19/24) [AD,S]
The Escape Hatch Identification: Leonard and Penny offer Sheldon's old room to Raj when he's forced to move out of his flat, leading to unexpected conflict. (S10 Ep18/24) [AD,S]
The Collaboration Fluctuation: Leonard, Penny and Raj settle into their new living arrangement, and Sheldon expresses an interest in Amy's professional life. (S10 Ep19/24) [AD,S]
The Birthday Synchronicity: Sheldon and Amy try to celebrate her birthday with an intimate night at home but are interrupted when Bernadette goes into labour. (S10 Ep11/24) [AD,S]
The Holiday Summation: After spending Christmas apart, the gang gather at Penny and Leonard's flat and hear about Sheldon and Amy's terrible trip to Texas. (S10 Ep12/24) [AD,S]
The Birthday Synchronicity: Sheldon and Amy try to celebrate her birthday with an intimate night at home but are interrupted when Bernadette goes into labour. (S10 Ep11/24) [AD,S]
The Holiday Summation: After spending Christmas apart, the gang gather at Penny and Leonard's flat and hear about Sheldon and Amy's terrible trip to Texas. (S10 Ep12/24) [AD,S]
The Monopolar Expedition: Leonard and Penny reconsider their feelings for each other, but then Leonard is offered the opportunity to spend the summer working at the North Pole. (S2 Ep23/23) [AD,S]
The Classified Materials Turbulence: Things look up for Leonard when Penny makes a surprising revelation on her second date with Stuart. Howard sees a flaw in his NASA project. (S2 Ep22/23) [AD,S]
The Vegas Renormalization: Leonard and Raj take a heartbroken Howard to Las Vegas, leaving Sheldon locked out of his flat and forced to stay with Penny. (S2 Ep21/23) [AD,S]
The Hofstadter Isotope: Leonard is devastated when Stuart from the comic book shop chats up Penny. Even worse, she doesn't mind. Sheldon tries to scupper the budding romance. (S2 Ep20/23) [AD,S]
The Dead Hooker Juxtaposition: Penny develops a rivalry with a sexy female neighbour who moves into the apartment building and threatens to become the 'new Penny'. (S2 Ep19/23) [AD,S]
The Work Song Nanocluster: Penny's home-based business selling hair accessories gets out of hand when an overexcited Sheldon takes charge of production. (S2 Ep18/23) [S,W]
The Terminator Decoupling: Leonard, Sheldon, Howard and Raj discover that beautiful sci-fi actress Summer Glau is on board their train to San Francisco. (S2 Ep17/23) [S]
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. (S2 Ep16/23) [S]
The Maternal Capacitance: A disastrous visit from Leonard's mother, Beverly, has the unexpected side-effect of bringing Leonard and Penny closer together. (S2 Ep15/23) [S]
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. (S2 Ep14/23) [S]
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. (S2 Ep13/23) [S]
The Killer Robot Instability: Kripke challenges the boys to a robot duel, while Howard is devastated when Penny finally tells him what she thinks of his chauvinism. (S2 Ep12/23) [S]
The Bath Item Gift Hypothesis: At Christmas, Leonard's hunky colleague starts dating Penny, while Sheldon's obsession with gift-giving etiquette torments everyone. (S2 Ep11/23) [AD,S]
The Vartabedian Conundrum: Leonard goes to Penny for help when his relationship with Stephanie takes off faster than he'd like, but will he act on her advice? (S2 Ep10/23) [AD,S]
The White Asparagus Triangulation: Sheldon is delighted that Leonard has finally found a girlfriend who matches up to his high standards... Perhaps a little too delighted. (S2 Ep9/23) [AD,S]
The Lizard-Spock Expansion: Howard is furious when a woman who he likes falls for Leonard instead, despite Howard's efforts to woo her. (S2 Ep8/23) [AD,S]
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 to bear. (S2 Ep6/23) [AD,S]
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. (S2 Ep5/23) [AD,S]
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. (S2 Ep4/23) [AD,S]
The Barbarian Sublimation: Penny becomes addicted to an online game based on the world of Conan the Barbarian and begins to pester Sheldon for advice. (S2 Ep3/23) [AD,S]
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. (S2 Ep2/23) [AD,S]
The Bad Fish Paradigm: Penny opens up to a reluctant Sheldon after a less-than-stellar first date with Leonard, putting him in the awkward position of having to keep a secret. (S2 Ep1/23) [AD,S]
The Tangerine Factor: When Penny breaks up with her boyfriend, Leonard plucks up the courage to ask her out. And each of them turns to Sheldon for advice about their date. (S1 Ep17/17) [AD,S]
The Peanut Reaction: Penny throws a surprise party for Leonard, with help from Howard and Raj, but Sheldon's indulgence in an electronics shop throws her off track. (S1 Ep16/17) [AD,S]
The Shiksa Indeterminacy: Leonard, Raj and Howard all fall heavily for Sheldon's twin sister, but when Leonard comes up with a plan to win her heart, it's derailed by Sheldon. (S1 Ep15/17) [AD,S]
The Nerdvana Annihilation: Penny makes fun of Leonard's habit of collecting goofy memorabilia, but his friends kick up a fuss and try to keep him on the side of the nerds. (S1 Ep14/17) [AD,S]
The Bat Jar Conjecture: Sheldon is ousted from the gang's Physics Bowl quiz team, so he decides to prove his superiority by forming his own team for the event. (S1 Ep13/17) [AD,S]
The Jerusalem Duality: Sheldon's confidence is shaken to the core by a 15-year-old physicist who is clearly much brighter than him. (S1 Ep12/17) [AD,S]
The Pancake Batter Anomaly: Penny volunteers to nurse Sheldon when he's sick. But his friends, who know how miserable he is when he's ill, stay well away. (S1 Ep11/17) [AD,S]
The Loobenfeld Decay: Leonard and Sheldon each tell a lie to avoid going to see Penny singing on stage in a production of Rent, but Sheldon's fib gets out of control. (S1 Ep10/17) [AD,S]
The Cooper-Hofstadter Polarization: Sheldon and Leonard fall out when they're asked to collaborate at a physics conference. Penny tries to help but just makes things worse. (S1 Ep9/17) [AD,S]
The Grasshopper Experiment: Raj panics when his parents arrange a blind date for him. But he discovers that he can talk to her - after a few drinks. (S1 Ep8/17) [AD,S]
The Dumpling Paradox: When Howard seduces Penny's friend and spends the night with her in Penny's flat, Penny asks if she can sleep on Leonard and Sheldon's sofa. (S1 Ep7/17) [AD,S]
The Hamburger Postulate: Leonard thinks he's been wasting his time on Penny, so he turns his attention to Leslie. Sheldon's uncomfortable with a change to his hamburger routine. (S1 Ep5/17) [AD,S]
The Luminous Fish Effect: Getting fired forces Sheldon to ponder life outside physics, so Leonard has to take drastic action to snap his friend out of his reverie. (S1 Ep4/17) [AD,S]
The Fuzzyboots Corollary: Leonard is upset when he discovers that Penny is seeing someone, so he plucks up the courage to ask a woman out on a date. (S1 Ep3/17) [AD,S]
The Big Bran Hypothesis: Bothered by how messy Penny's flat is, Sheldon sneaks in to clean and organise it, but Penny isn't best pleased when she finds out. (S1 Ep2/17) [AD,S]
Pilot: The first ever episode of the hit sitcom. Leonard and Sheldon's ignorance of women seems set to change when the beautiful Penny moves in next door. (S1 Ep1/17) [AD,S]
The Long Distance Dissonance: The gang worry when Sheldon's former admirer, Dr Ramona Nowitzki, turns up while Amy is away working at Princeton. (S10 Ep24/24) [AD,S]
The Gyroscopic Collapse: Amy is offered a fellowship at Princeton, Raj makes new living arrangements, and the guys' gyroscope project spins out of control. (S10 Ep23/24) [AD,S]
The Cognition Regeneration: Leonard isn't happy when he finds out that Penny is considering accepting a job offer from her ex-boyfriend Zack. (S10 Ep22/24) [AD,S]
The Separation Agitation: Howard and Bernadette are upset when they leave Halley at the nursery. Bert the geologist introduces his girlfriend to the gang. (S10 Ep21/24) [AD,S]
The Recollection Dissipation: Sheldon collaborates on two projects - one with Leonard and Howard, plus another with Amy - pushing himself to the limit. (S10 Ep20/24) [AD,S]
The Collaboration Fluctuation: Leonard, Penny and Raj settle into their new living arrangement, and Sheldon expresses an interest in Amy's professional life. (S10 Ep19/24) [AD,S]
The Escape Hatch Identification: Leonard and Penny offer Sheldon's old room to Raj when he's forced to move out of his flat, leading to unexpected conflict. (S10 Ep18/24) [AD,S]
The Comic-Con Conundrum: Cut off from his father's fortune, Raj appoints Sheldon to organise his finances. Penny considers joining the guys at Comic-Con. (S10 Ep17/24) [AD,S]
The Allowance Evaporation: Amy is furious when she learns that Sheldon has shared intimate details of their relationship with his colleagues. (S10 Ep16/24) [AD,S]
The Locomotion Reverberation: Leonard and Howard distract Sheldon with a trip to a historic railway when he slows their progress on the guidance system. (S10 Ep15/24) [AD,S]
The Emotion Detection Automation: Sheldon tests a new invention after hearing that it could help him to read people's emotions. Raj seeks dating advice. (S10 Ep14/24) [AD,S]
Executive ProducerChuck LorreSupervising ProducerPeter ChakosProducerKristy CecilCo-producerMary T. QuigleyAssociate ProducerRyan BerdanCoordinating ProducerSuzanne MccormackExecutive Story EditorAnthony Del BroccoloShow EditorTara HernandezMain CastJohnny Galecki ( Leonard Hofstadter )Jim Parsons ( Sheldon Cooper )Kaley Cuoco-sweeting ( Penny )Simon Helberg ( Howard Wolowitz )Kunal Nayyar ( Raj Koothrappali )Melissa Rauch ( Bernadette Rostenkowski )Mayim Bialik ( Amy Farrah Fowler )Todd Eric Andrews ( Dr. Gunderson )Ayumi Iizuka ( Scientist )
Director Of PhotographySteven V. Silver, AscProduction DesignerJohn ShaffnerEdited ByPeter ChakosUnit Production ManagerJay O'connellFirst Assistant DirectorAnthony RichSecond Assistant DirectorNicole LorreCasting ByNikki Valko, C.s.a.Ken Miller, C.s.a.Casting AssociateTara TreacyTheme Written And Performed ByBarenaked LadiesScience ConsultantDavid Saltzberg, Ph.d.Costume DesignerMary T. QuigleyMake-up ArtistsVikki MctlarterPeggy Nichols
Hair StylistsFaye WoodsSylvia SurduSet DecoratorAnn Shea, S.d.s.a.Property MasterScott L. LondonAssociate DirectorGay LinvillScript SupervisorJulie FleischerArt DirectorFrancorse Cherry-cohenProduction CoordinatorJustrn D. HetzelAssistant Property MasterSam HustonProduction Sound MixerBruce PetersRe-recording MixersCharlie McdanielBob La Masney