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The Big Bang Theory

Season 5 2011 - 2012

  • 2011-09-23T00:00:00Z on CBS
  • 22 mins
  • 8 hours, 9 mins (24 episodes)
  • United States
  • English
  • Comedy

In season five, Penny and Leonard's relationship is relaunched in full "beta test" mode, while Sheldon, Howard, and Raj discover the feminine mystique is something that cannot be easily graphed or calculated. As Sheldon makes begrudging amendments to his "Relationship Agreement" with his "friend-who-happens-to-be-a-girl" Amy Farrah Fowler, Raj contemplates an arranged marriage, and Howard is all-systems-go for both is NASA space launch and wedding to the spirited Bernadette.


24 episodes

5x01 The Skank Reflex Analysis

  • Season Premiere

    2011-09-23T00:00:00Z — 21 mins

Penny is worried with how damaged her friendship with the guys will be in the aftermath of her sleeping with Raj while Sheldon becomes the leader of the paintball team.

5x02 The Infestation Hypothesis

  • 2011-09-23T00:00:00Z — 19 mins

A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up his long-distance relationship with Priya.

Leonard and Amy get to know each other better, while Howard and Bernadette spend the weekend with Mrs. Wolowitz.

5x04 The Wiggly Finger Catalyst

  • 2011-10-07T00:00:00Z — 20 mins

Penny plays Matchmaker for Raj, which results in him finding a girl he is comfortable talking to.

5x05 The Russian Rocket Reaction

  • 2011-10-14T00:00:00Z — 21 mins

Sheldon and Leonard get invited to a party at Wil Wheaton's house, and Howard gets an out-of-this-world opportunity.

5x06 The Rhinitis Revelation

  • 2011-10-21T00:00:00Z — 21 mins

Sheldon's mother, Mary Cooper, comes to visit, but Sheldon is annoyed that she also spends time with the rest of the gang, instead of catering to his every demand.

5x07 The Good Guy Fluctuation

  • 2011-10-28T00:00:00Z — 19 mins

A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to scare the guys for Halloween.

5x08 The Isolation Permutation

  • 2011-11-04T00:00:00Z — 21 mins

Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping without her.

5x09 The Ornithophobia Diffusion

  • 2011-11-11T01:00:00Z — 21 mins

Leonard and Penny try hanging out as friends on a 'non-date', but end up purposely ruining each others chances with perspective dates. Meanwhile, Sheldon enlists the help of Bernadette and Amy to overcome his fear of birds.

Sheldon considers taking his relationship with Amy to the next level when Stuart from the comic book store asks her out on a date.

5x11 The Speckerman Recurrence

  • 2011-12-09T01:00:00Z — 19 mins

Leonard must face his fears after being contacted by his high school tormentor.

5x12 The Shiny Trinket Maneuver

  • 2012-01-13T01:00:00Z — 20 mins

Sheldon gets in trouble with Amy when he isn't impressed by her recent accomplishment, and Howard must come to grips with Bernadette's dislike of children.

Leonard, who broke up with Priya, asks Penny out to a spur-of the-moment romantic dinner for two, and the duo contemplates on their relationship.

5x14 The Beta Test Initiation

  • 2012-01-27T01:00:00Z — 20 mins

Leonard and Penny deal with the idea of starting a relationship again and Raj finally finds a "woman" he can talk to without being drunk, in the form of Siri on his new phone. Meanwhile, Sheldon decides to start a YouTube series entitled "Sheldon Cooper presents Fun with Flags" with the help of Amy.

5x15 The Friendship Contraction

  • 2012-02-03T01:00:00Z — 20 mins

Sheldon's selfish demands force Leonard to reconsider their friendship. Meanwhile, Wolowitz tries to pick his astronaut nickname.

5x16 The Vacation Solution

  • 2012-02-10T01:00:00Z — 21 mins

When Sheldon is forced to take his vacation, he goes to work with Amy in her neurobiology lab.

5x17 The Rothman Disintegration

  • 2012-02-17T01:00:00Z — 21 mins

Penny is horrified when Amy gives her a gift: a huge, quite horrible painting of the two of them. With no good way to avoid displaying it, she only hangs it up when Amy is over. When Amy catches her taking the painting down, she's embarrassed and angry until Penny lies and says the gift made Bernadette jealous. When the deranged Professor Rothman is forced to retire, both Sheldon and Kripke vie for his office. President Siebert refuses to resolve the dispute, so Leonard arranges a one-on-one basketball game to decide (since they're both equally bad at sports). Neither one can even make a single basket, so they end up deciding by seeing who can bounce the ball the highest. Sheldon wins; unfortunately, the office is not what he'd hoped for: the thermostat is located in the office of a professor going through the hot flashes of menopause (thus Sheldon is too cold), the mockingbird outside his window is off-key with the annoying windchimes, the perpetually naked Professor Rothman refuses to vacate, and the Geology Department upstairs makes too much noise. Finally, Sheldon gets his head stuck in the wall in an existing hole, after which Leonard takes his picture before he goes for help.

5x18 The Werewolf Transformation

  • 2012-02-24T01:00:00Z — 21 mins

Sheldon becomes agitated when his regular barber is out sick. Astronaut training causes Howard to reconsider wanting to go into space. Penny beats Leonard in chess, the first time she plays.

5x19 The Weekend Vortex

  • 2012-03-09T01:00:00Z — 20 mins

Sheldon must choose between joining Amy at her aunt's birthday party or playing videogames all weekend with the guys.

5x20 The Transporter Malfunction

  • 2012-03-30T00:00:00Z — 21 mins

Penny buys Leonard and Sheldon “Star Trek” collectibles as a thank-you, leading Sheldon to be haunted by Mr. Spock. Meanwhile, Raj decides he has met the “Future Mrs. Koothrappali” after his parents set him up on a date.

5x21 The Hawking Excitation

  • 2012-04-06T00:00:00Z — 19 mins

When Wolowitz gets to work with Stephen Hawking, Sheldon is willing to do anything to meet his hero.

5x22 The Stag Convergence

  • 2012-04-27T00:00:00Z — 21 mins

After the guys throw Howard a bachelor party, Bernadette reconsiders marrying him after learning about his sexual history.

5x23 The Launch Acceleration

  • 2012-05-04T00:00:00Z — 21 mins

When NASA moves up Howard's mission, he must face his fears and Bernadette's dad, thus putting the wedding plans in jeopardy. Meanwhile, Leonard says something surprising to Penny in the bedroom.

5x24 The Countdown Reflection

  • 2012-05-11T00:00:00Z — 21 mins

The fifth season ends with Howard and Bernadette deciding to get married before his NASA mission, causing the gang to scurry into overdrive in an effort to stage the wedding. NASA astronaut Mike Massimino has a cameo as himself.