The Big Bang Theory

List of The Big Bang Theory episodes (season 4)

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The Big Bang Theory Season 4 DVD

DVD Cover for Season 4

Main article: Season 4

This is a list of episodes for the fourth season of The Big Bang Theory, which began airing on CBS on September 23, 2010.[1] During the season, actress Kaley Cuoco was absent from some episodes after she broke her leg in a horse-riding accident. When she returned to the series, she was shown working as a bartender, instead of waitressing at her usual workplace as The Cheesecake Factory so as to hide the fact that she had a cast on her leg.

Cast Edit


Chuck Lorre Vanity Card Cast Rules

Main article: List of The Big Bang Theory characters
  • Sheldon Cooper, Ph.D., portrayed by Jim Parsons, is a theoretical physicist. Originally from East Texas, he was a child prodigy, starting college at the age of 11, right after completing the fifth grade. He has an IQ of 187 and exhibits a strict adherence to routine; a lack of understanding of irony, sarcasm, and humor; and a complete lack of humility. He is currently spending time with Amy Farrah Fowler, who is a girl and a friend, but not his girlfriend though they have similar personalities.
  • Leonard Hofstadter Ph.D., portrayed by Johnny Galecki, is an experimental physicist with an IQ of 173 who received his Ph.D when he was 24 years old. He shares an apartment with colleague and friend, Sheldon Cooper. He and Penny dated at one point during the series, but they have since broken up. He is dating Raj's sister Priya.
  • Penny, portrayed by Kaley Cuoco, is the attractive, blonde neighbor who lives across the hall from Sheldon and Leonard. She has aspirations to a career in show business, and has been to casting calls and auditions but has not been successful so far. To pay the bills, she works as a waitress at The Cheesecake Factory. Her last name has never been revealed. She and Leonard dated during the third season, but they have since broken up.
  • Howard Wolowitz, M.Eng., portrayed by Simon Helberg, works as an aerospace engineer. He is Jewish, and lives with his mother. Unlike Sheldon, Leonard, and Raj, Howard lacks a Ph.D. He defends this by pointing out that he has a master's degree in Engineering from MIT and the apparatus he designs are actually built and launched into space, unlike the purely abstract work of his friends. He provides outrageous pick-up lines and fancies himself a ladies-man with suitably unimpressed reactions from Penny; however, he has limited success with other women. He is dating and now engaged to Bernadette Rostenkowski.
  • Rajesh Koothrappali, Ph.D., portrayed by Kunal Nayyar, originally comes from New Delhi, India. Known commonly as "Raj", he works alongside Sheldon exploring the string theory implications of gamma rays from dark matter annihilation. He is very shy around women and is physically unable to talk to them unless he drinks alcohol. However, he has much better luck with women as opposed to his overly confident best friend Howard.
  • Bernadette Rostenkowski, portrayed by Melissa Rauch, is a waitress and Pennys co-worker paying her way through graduate school microbiology studies. Bernadette is introduced to Howard by Penny. At first she and Howard do not get along, as they appear to have nothing in common. When they find out that they both have overbearing mothers, they feel a connection and have since become engaged. She was upgraded to main cast status in the episode The Hot Troll Deviation.
  • Amy Farrah Fowler, Ph.D., portrayed by Mayim Bialik, is a woman Raj and Howard meet on an online dating site using a faux account for Sheldon. She is essentially a female duplicate of Sheldon and they become friends. Sheldon is adamant about the fact that "she is a girl and is his friend, but she is not his girlfriend". She was upgraded to main cast status in the episode The 21-Second Excitation.

Kaley Cuoco's broken leg Edit

During this season, Kaley Cuoco broke her left leg in a horse-riding accident and missed two episodes, The Desperation Emanation and The Irish Pub Formulation. When she returned, she was shown working as a bartender, instead of in her normal employment as a waitress at The Cheesecake Factory. Her cast was concealed, and no mention of the unseen broken leg was made. A body double was used in scenes where Penny walks, such as near the end of The 21-Second Excitation.[2]

Episodes Edit

Episode (Series) Episode (Season) Title Original Air Date Directed By Description
64 1 The Robotic Manipulation September 23, 2010

Mark Cendrowski

Howard demonstrates a robotic arm that he "borrowed" from the Jet Propulsion Laboratory. Penny comes to know of Sheldon's new friend, Amy Farrah Fowler, and asks him to take Amy on a date. It is Sheldon's first date and Penny is roped into accompanying him. Meanwhile, Howard continues experimenting with the robotic arm in more creative ways.

65 2 The Cruciferous Vegetable Amplification September 30, 2010

Mark Cendrowski

Sheldon's best estimate for his life expectancy means he will miss the point in time when man will be able to transfer his consciousness into machines and achieve immortality. He changes his diet and starts to exercise in hopes of extending his life expectancy. Since he injures himself going down for a jog, Sheldon decides on an alternate plan to extend his life expectancy: building a robotic replica of himself.

66 3 The Zazzy Substitution October 7, 2010

Mark Cendrowski

Amy and Sheldon disagree on whose field of science is better and they break up, causing Sheldon to get 25 cats to fill the void left by Amy. When Leonard realizes how serious Sheldon's problem is, he calls in Sheldon's mother for help.

67 4 The Hot Troll Deviation October 14, 2010

Mark Cendrowski

When the guys run into Howard's ex at the Cheesecake Factory, he ends up confronting his lingering feelings for her. He seeks help from Penny, who agrees on the condition that Howard reveal the reason behind his breakup. He confesses that Bernadette caught him engaging in cybersex with a fellow World of Warcraft player. Howard and Bernadette discuss their relationship at the restaurant and make amends deciding to give it another try.

68 5 The Desperation Emanation October 21, 2010

Mark Cendrowski

When Amy Farrah Fowler wants to introduce Sheldon to her mother, the implications worry Sheldon. He still adamantly says that Amy is his friend but not his "girlfriend". Leonard reveals to him that he can't say that anymore, so it freaks him out and he tries to "break up" with her.

69 6 The Irish Pub Formulation October 28, 2010

Mark Cendrowski

Raj's sister Priya (Aarti Mann) visits and inadvertently causes trouble for the friends. Leonard and she apparently have a history, despite Leonard's pinky swear with Howard that they would not interact with her in deference to Raj. They hook up, but are discovered by Sheldon, who devises an elaborate lie to cover it up.

70 7 The Apology Insufficiency November 4, 2010

Mark Cendrowski

When Howard attempts to receive a higher security clearance, his friends are interviewed by a formidable FBI agent checking into Howard's past. Raj, Leonard, and Sheldon don't give the most helpful interviews.

71 8 The 21-Second Excitation November 11, 2010

Mark Cendrowski

Sheldon, Leonard, Raj, and Howard excitedly plan to attend a screening of Raiders of the Lost Ark that includes 21 seconds of never-before-seen footage. However, they get to the theater late and have to wait at the end of a long line. Amy crashes Penny and Bernadette's girls-night-in.

72 9 The Boyfriend Complexity November 18, 2010

Mark Cendrowski

Leonard is surprised when he shows up at Penny's door and gets a kiss from Penny. Later, Penny informs him that her critical father, Wyatt (Keith Carradine), is visiting, and she asks him to pretend that they're back together because he's the only boyfriend she's ever had that her father likes.

73 10 The Alien Parasite Hypothesis December 9, 2010 Mark Cendrowski

Amy begins to have feelings for Penny's ex, Zack, whom she meets in a bar on a night out with Penny and Bernadette. Amy and Sheldon later discuss her symptoms and come to the reluctant conclusion that she was aroused.

74 11 The Justice League Recombination December 16, 2010 Mark Cendrowski

The guys get Penny's friend Zack to be Superman and Penny to be Wonder Woman in their Justice League of America entry at the comic book store New Year's Eve costume party. Penny nearly backs out and almost tells Leonard that she hasn't gotten over him.

75 12 The Bus Pants Utilization Jan 6, 2011 Mark Cendrowski

Sheldon, Howard and Raj are eating together in the Cafeteria when Leonard approaches them with an idea for a smartphone app that helps users solve Differential Equations. Sheldon ends up kicked off the project due to his condescending comments, which makes him have to hang out in Penny's apartment.

76 13 The Love Car Displacement Jan 20, 2011 Mark Cendrowski

Leonard, Sheldon, Howard, Raj, Amy, and Bernadette are invited to give a speech at a symposium on the Impact of Current Scientific Research on Social Interaction. Amy reveals Penny as her best friend and invites her to come along as Amy's "plus one". Due to different causes, there is a lot of bed hopping and Penny ends up in Leonard's bed.

77 14 The Thespian Catalyst Feb 3, 2011 Mark Cendrowski

Sheldon gives a lecture in a class, and, as usual, makes his condescending comments. Meanwhile, the gang is enjoying the tweets of the people at Sheldon's lecture, which are all negative. Sheldon is shocked at their comments. Following a suggestion from Amy, Sheldon takes acting lessons from Penny.

78 15 The Benefactor Factor Feb 10, 2011 Mark Cendrowski

President Siebert (Joshua Malina) coerces the gang to attend a fundraiser for the university. Leonard finds one older widow who wants to give his department money in exchange for sex.

79 16 The Cohabitation Formulation Feb 17, 2011 Mark Cendrowski

Bernadette doesn't like it when Howard leaves immediately after sex, so she asks him to consider living together. He is unsure at first, but after hearing his overbearing mother's comments one more time, he snaps and moves in with Bernadette.

80 17 The Toast Derivation Feb 24, 2011 Mark Cendrowski

Sheldon is upset when he realizes Leonard is the center of their group of friends. When the gang starts hanging out at Raj's, Sheldon decides, on advice of Amy and Penny, to get a new group of friends, which consists of Kripke, Stuart, Zack, and LeVar Burton.

81 18 The Prestidigitation Approximation Mar 10, 2011 Mark Cendrowski

Priya asks Leonard to tell Penny to not hang around as much. In the cafeteria, Howard offers to show Raj a magic trick, and Sheldon intervenes and tells him he shouldn't be wasting his time with such trivial matters.

82 19 The Zarnecki Incursion Mar 31, 2011 Peter Chakos

Sheldon's World Of Warcraft account is hacked and his character was raided clean. The boys are determined to track down this hacker. Penny shares some girl talk with Bernadette and Amy about Leonard and Priya.

83 20 The Herb Garden Germination April 7, 2011 Mark Cendrowski

Amy and Sheldon conduct an experiment to see how quickly gossip spreads within their group by spreading gossip of their own.

84 21 The Agreement Dissection April 28, 2011 Mark Cendrowski

Sheldon barges into the bathroom while Leonard is using the shower. When Leonard points out Priya is in the shower with him, Sheldon is angered and says it is a violation of the Roommate Agreement. Priya takes a look at the document and finds loop holes that are finally to Leonard's advantage.

85 22 The Wildebeest Implementation May 5, 2011 Mark Cendrowski

Penny spies on Leonard and Priya at a dinner party using Bernadette as the informer, and Raj tries to figure out how to cure his anxiety.

86 23 The Engagement Reaction May 12, 2011 Howard Murray

Howard tells his mother about his engagement with Bernadette, which puts his mother into the hospital. Penny tries to get closer to Priya to remain in the gang.

87 24 The Roommate Transmogrification May 19, 2011 Mark Cendrowski

After Bernadette receives a Ph.D, the guys seize the opportunity to mock Howard for being the only non-doctor in their group. Meanwhile, Raj becomes Sheldon's new roommate because Leonard spends so much time with Priya at his apartment. Penny starts getting closer to Raj.


U.S. Nielsen Ratings Edit

Episode # Title Air Date Rating Share 18-49 Viewers
1 The Robotic Manipulation September 23, 2010 8.4 14 4.8/15 13.95
2 The Cruciferous Vegetable Amplification September 30, 2010 7.6 13 4.4/14 13.06
3 The Zazzy Substitution October 7, 2010 7.6 13 4.1/13 12.59
4 The Hot Troll Deviation October 14, 2010 7.6 13 4.3/14 12.57
5 The Desperation Emanation October 21, 2010 7.9 13 4.1/13 13.05
6 The Irish Pub Formulation October 28, 2010 7.8 13 4.2/13 13.04
7 The Apology Insufficiency November 4, 2010 8.4 14 4.7/14 14.00
8 The 21-Second Excitation November 11, 2010 7.7 13 4.2/12 13.11
9 The Boyfriend Complexity November 18, 2010 7.7 13 4.3/13 13.02
10 The Alien Parasite Hypothesis December 9, 2010 7.2 12 3.9/12 12.03
11 The Justice League Recombination December 16, 2010 7.9 13 4.0/13 13.24
12 The Bus Pants Utilization January 6, 2011 8.2 14 4.4/13 13.98
13 The Love Car Displacement January 20, 2011 8.1 13 4.2/12 13.63
14 The Thespian Catalyst February 3, 2011 8.0 13 4.3/12 13.83
15 The Benefactor Factor February 10, 2011 7.6 12 3.9/11 12.79
16 The Cohabitation Formulation February 17, 2011 7.4 12 3.7/11 12.41
17 The Toast Derivation February 24, 2011 7.4 12 3.8/11 12.35
18 The Prestidigitation Approximation March 10, 2011 7.3 12 3.8/11 12.06
19 The Zarnecki Incursion March 31, 2011 7.2 12 3.7/12 11.92
20 The Herb Garden Germination April 7, 2011 6.9 12 3.7/12 11.39
21 The Agreement Dissection April 28, 2011 6.4 11 3.3/11 10.71
22 The Wildebeest Implementation May 5, 2011 6.5 11 3.4/11 10.50
23 The Engagement Reaction May 12, 2011 6.5 11 3.4/11 10.78
24 The Roommate Transmogrification May 19, 2011 TBA TBA TBA 11.30

Canadian ratingsEdit

Order Episode Viewers
1 "The Robotic Manipulation" 3.112 #1[3]
2 "The Cruciferous Vegetable Amplification" 2.964 #1[4]
3 "The Zazzy Substitution" 2.692 #1[5]
4 "The Hot Troll Deviation" 2.837 #2[6]
5 "The Desperation Emanation" 3.028 #1[7]
6 "The Irish Pub Formulation" 3.204 #1[8]
7 "The Apology Insufficiency" 3.408 #1[9]
8 "The 21-Second Excitation" 3.304 #1[10]
9 "The Boyfriend Complexity" 3.247 #1[11]
10 "The Alien Parasite Hypothesis" 2.659 #3[12]
11 "The Justice League Recombination" 3.021 #1[13]
12 "The Bus Pants Utilization" 3.334 #3[14]
13 "The Love Car Displacement" 3.189 #1[15]
14 "The Thespian Catalyst" 3.192 #3[16]
15 "The Benefactor Factor" 3.123 #2[17]
16 "The Cohabitation Formulation" 3.462 #1[18]
17 "The Toast Derivation" 3.447 #2[19]
18 "The Prestidigitation Approximation" 3.132 #1[20]
19 "The Zarnecki Incursion" 3.216 #1[21]
20 "The Herb Garden Germination" 3.219 #1[22]
21 "The Agreement Dissection" 2.624 #4[23]
22 "The Wildebeest Implementation" 3.028 #1[24]
23 "The Engagement Reaction" 2.936 #2[25]
24 "The Roommate Transmogrification" 3.448 #1[26]

UK ratingsEdit

The series is currently airing Thursday nights at 9pm on E4]. All viewing figures and ranks are sourced from BARB.[27] Viewers are in 000's.

Order Episode Airdate E4 E4 +1 Total Rank(cable)
Viewersa Rankb Viewersa Rankb
1 "The Robotic Manipulation" November 4, 2010 877 #1 256 #6 1,143 #19
2 "The Cruciferous Vegetable Amplification" November 11, 2010 812 #2 219 #3 1,061 #19
3 "The Zazzy Substitution" November 18, 2010 718 #2 252 #1 970 #27
4 "The Hot Troll Deviation" November 25, 2010 720 #2 258 #3 978
5 "The Desperation Emanation" December 2, 2010 715 #3 333 #4 1,048
6 "The Irish Pub Formulation" December 9, 2010 786 #3
786 #2
7 "The Apology Insufficiency" December 16, 2010 832 #4
832 #13
8 "The 21-Second Excitation" December 23, 2010 749 #3
9 "The Boyfriend Complexity" December 30, 2010 764 #1 302 #2 1,066
10 "The Alien Parasite Hypothesis" January 6, 2011 944 #1 248 #4 1,192 #17
11 "The Justice League Recombination" January 13, 2011 825 #2 213 #7 1,038 #19
12 "The Bus Pants Utilization" January 20, 2011 870 #2 232 #7 1,172 #15

aViewers in thousands. bRank for individual channels only.

Australian ratings Edit

Order Episode Original airdate Viewers
1 "The Robotic Manipulation" 20 October 2010 1.179[28] 6[29] 15[28]
2 "The Cruciferous Vegetable Amplification" 27 October 2010 1.146[30] 5[31] 20[30]
3 "The Zazzy Substitution" 10 November 2010 1.151[32] 6[33] 21[32]
4 "The Hot Troll Deviation" 8 February 2011 0.922[34] 11[34] Unknown[35]
5 "The Desperation Emanation" 9 February 2011 0.884[34] 11[34] Unknown[35]
6 "The Irish Pub Formulation" 15 February 2011 0.958[36] 9[36] TBA
7 "The Apology Insufficiency" 16 February 2011 0.964[36] 7[36] TBA
8 "The 21-Second Excitation" 23 February 2011 0.852[37] 9[38]


See also Edit

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