The Big Bang Theory : Season 4

    • Air date: 23 Sep '10 24 episodes
      This season the Big Bang gang’s romantic universe expands. On the rebound from Penny, Leonard falls into the arms of Raj’s sister Priya. Sheldon gets a girlfriend, or rather a friend who is a girl: Amy, a dour neurobiologist who declares herself besties with Penny. Howard and Bernadette heat up. And so do Raj and Bernadette (at least in Raj’s Bollywood daydream). All in the furtherance of award-winning genius comedy.
  • List of Episodes (24)

    1. The Robotic Manipulation

    • Penny tags along on Sheldon's first ever date; Wolowitz finds a new use for a robotic arm.

    2. The Cruciferous Vegetable Amplification

    • Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.

    3. The Zazzy Substitution

    • The guys are concerned as Sheldon searches for an alternative to human companionship.

    4. The Hot Troll Deviation

    • An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.

    5. The Desperation Emanation

    • Leonard realizes he’s the only one without a girlfriend, while Sheldon wants to get rid of his.

    6. The Irish Pub Formulation

    • Leonard keeps an affair a secret from Sheldon, Howard and Raj.

    7. The Apology Insufficiency

    • Sheldon's answers during an FBI interview put Wolowitz's security clearance in jeopardy.

    8. The 21-second Excitation

    • While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.

    9. The Boyfriend Complexity

    • Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.

    10. The Alien Parasite Hypothesis

    • Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.

    11. The Justice League Recombination

    • The guys find a "super" use for Penny's new boyfriend, Zack, when they enter a costume contest as the Justice League.

    12. The Bus Pants Utilization

    • Leonard's idea for a smartphone app derails his friendship with Sheldon.

    13. The Love Car Displacement

    • Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.

    14. The Thespian Catalyst

    • Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.

    15. The Benefactor Factor

    • A wealthy donor to the university makes Leonard consider how far he's willing to go for the sake of science.

    16. The Cohabitation Formulation

    • As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj's sister.

    17. The Toast Derivation

    • Sheldon becomes concerned when everybody begins to hang out at Raj's apartment and discovers Leonard is the center of the group.

    18. The Prestidigitation Approximation

    • Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.

    19. The Zarnecki Incursion

    • Sheldon's World of Warcraft online game account is hacked and he is determined to find out who did it. Also Penny shares some girl talk with her friends about Leonard and his new girlfriend. When Howard discovers who hacked the account, the guys depart for a quest to Carlsbad, California where the hacker, Todd Zarnecki, lives in order to retrieve the stolen account, along with "enchanted weapons, gladiator armor, gold, and a battle ostrich, Glenn". Despite Sheldon carrying his Bat'leth with him

    20. The Herb Garden Germination

    • Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to even higher level.

    21. The Agreement Dissection

    • When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violations of the roommate agreement. However, before he can get too far, Priya uses her skills as a lawyer to nullify the charges due to the agreement's vague wording, much to Sheldon's dismay. When the guys take advantage of Priya's skills in order to eat Greek food on pizza night, Sheldon goes to Penny, who invites him to a girls' night out with Amy and Bernadette, which Sheldon agrees to after Penny

    22. The Wildebeest Implementation

    • Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.

    23. The Engagement Reaction

    • When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.

    24. The Roommate Transmogrification

    • When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she's regrets.