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.

Season episodes list 5

S05E01

S05E01 : The Skank Reflex Analysis 8.11/10 (aired on 09/22/2011)

Penny is worried with how damaged her friendship with the guys will be in the aftermath of her…
S05E02

S05E02 : The Infestation Hypothesis 8.12/10 (aired on 09/22/2011)

A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up…
S05E03

S05E03 : The Pulled Groin Extrapolation 7.86/10 (aired on 09/29/2011)

Leonard and Amy get to know each other better, while Howard and Bernadette spend the weekend with…
S05E04

S05E04 : The Wiggly Finger Catalyst 7.95/10 (aired on 10/06/2011)

Penny plays Matchmaker for Raj, which results in him finding a girl he is comfortable talking to.
S05E05

S05E05 : The Russian Rocket Reaction 8.12/10 (aired on 10/13/2011)

Sheldon and Leonard get invited to a party at Wil Wheaton's house, and Howard gets an…
S05E06

S05E06 : The Rhinitis Revelation 7.77/10 (aired on 10/20/2011)

Sheldon's mother, Mary Cooper, comes to visit, but Sheldon is annoyed that she also spends time…
S05E07

S05E07 : The Good Guy Fluctuation 8.6/10 (aired on 10/27/2011)

A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to…
S05E08

S05E08 : The Isolation Permutation 7.84/10 (aired on 11/03/2011)

Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping…
S05E09

S05E09 : The Ornithophobia Diffusion 8.19/10 (aired on 11/10/2011)

Leonard and Penny try hanging out as friends on a 'non-date', but end up purposely ruining each…
S05E10

S05E10 : The Flaming Spittoon Acquisition 8.01/10 (aired on 11/17/2011)

Sheldon considers taking his relationship with Amy to the next level when Stuart from the comic…
S05E11

S05E11 : The Speckerman Recurrence 7.48/10 (aired on 12/08/2011)

Leonard must face his fears after being contacted by his high school tormentor.
S05E12

S05E12 : The Shiny Trinket Maneuver 7.85/10 (aired on 01/12/2012)

Sheldon gets in trouble with Amy when he isn't impressed by her recent accomplishment, and Howard…
S05E13

S05E13 : The Recombination Hypothesis 8.21/10 (aired on 01/19/2012)

Leonard, who broke up with Priya, asks Penny out to a spur-of the-moment romantic dinner for two,…
S05E14

S05E14 : The Beta Test Initiation 8.31/10 (aired on 01/26/2012)

Leonard and Penny deal with the idea of starting a relationship again and Raj finally finds a…
S05E15

S05E15 : The Friendship Contraction 7.85/10 (aired on 02/02/2012)

Sheldon's selfish demands force Leonard to reconsider their friendship. Meanwhile, Wolowitz tries…
S05E16

S05E16 : The Vacation Solution 7.76/10 (aired on 02/09/2012)

When Sheldon is forced to take his vacation, he goes to work with Amy in her neurobiology lab.
S05E17

S05E17 : The Rothman Disintegration 7.93/10 (aired on 02/16/2012)

Penny is horrified when Amy gives her a gift: a huge, quite horrible painting of the two of them.…
S05E18

S05E18 : The Werewolf Transformation 8.31/10 (aired on 02/23/2012)

Sheldon becomes agitated when his regular barber is out sick. Astronaut training causes Howard to…
S05E19

S05E19 : The Weekend Vortex 8.2/10 (aired on 03/08/2012)

Sheldon must choose between joining Amy at her aunt's birthday party or playing videogames all…
S05E20

S05E20 : The Transporter Malfunction 8.2/10 (aired on 03/29/2012)

Penny buys Leonard and Sheldon “Star Trek” collectibles as a thank-you, leading Sheldon to be…
S05E21

S05E21 : The Hawking Excitation 8.58/10 (aired on 04/05/2012)

When Wolowitz gets to work with Stephen Hawking, Sheldon is willing to do anything to meet his hero.
S05E22

S05E22 : The Stag Convergence 7.86/10 (aired on 04/26/2012)

After the guys throw Howard a bachelor party, Bernadette reconsiders marrying him after learning…
S05E23

S05E23 : The Launch Acceleration 8.22/10 (aired on 05/03/2012)

When NASA moves up Howard's mission, he must face his fears and Bernadette's dad, thus putting the…
S05E24

S05E24 : The Countdown Reflection 8.51/10 (aired on 05/10/2012)

The fifth season ends with Howard and Bernadette deciding to get married before his NASA mission,…