The Big Bang Theory - Season 5

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

The Skank Reflex Analysis

Season 5 - Episode 1

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 l...

The Infestation Hypothesis

Season 5 - Episode 2

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

The Pulled Groin Extrapolation

Season 5 - Episode 3

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

The Wiggly Finger Catalyst

Season 5 - Episode 4

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

The Russian Rocket Reaction

Season 5 - Episode 5

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

The Rhinitis Revelation

Season 5 - Episode 6

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 cateri...

The Good Guy Fluctuation

Season 5 - Episode 7

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

The Isolation Permutation

Season 5 - Episode 8

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

The Ornithophobia Diffusion

Season 5 - Episode 9

Leonard and Penny try hanging out as friends on a 'non-date', but end up purposely ruining each others chances with perspective dates. Meanw...

The Flaming Spittoon Acquisition

Season 5 - Episode 10

When Stuart asks Amy out on a date, Sheldon must confront his feelings and consider where his relationship with Amy is going.

The Speckerman Recurrence

Season 5 - Episode 11

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

The Shiny Trinket Maneuver

Season 5 - Episode 12

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

The Recombination Hypothesis

Season 5 - Episode 13

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 relation...

The Beta Test Initiation

Season 5 - Episode 14

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 Friendship Contraction

Season 5 - Episode 15

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

The Vacation Solution

Season 5 - Episode 16

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

The Rothman Disintegration

Season 5 - Episode 17

Sheldon battles Kripke for a coveted office at the university. Penny receives a very unusual gift from Amy.

The Werewolf Transformation

Season 5 - Episode 18

Sheldon becomes agitated when his regular barber is out sick. Astronaut training causes Howard to reconsider wanting to go into space. Penny...

The Weekend Vortex

Season 5 - Episode 19

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

The Transporter Malfunction

Season 5 - Episode 20

Penny buys Leonard and Sheldon “Star Trek” collectibles as a thank-you, leading Sheldon to be haunted by Mr. Spock. Meanwhile, Raj decides h...

The Hawking Excitation

Season 5 - Episode 21

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

The Stag Convergence

Season 5 - Episode 22

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

The Launch Acceleration

Season 5 - Episode 23

When NASA moves up Howard's mission, he must face his fears and Bernadette's dad, thus putting the wedding plans in jeopardy. Meanwhile, Leo...

The Countdown Reflection

Season 5 - Episode 24

The fifth season ends with Howard and Bernadette deciding to get married before his NASA mission, causing the gang to scurry into overdrive ...