For the first three seasons, Galecki, Parsons, and Cuoco, the three main stars of the show, received at most $60,000 per episode. The salary for the three went up to $200,000 per episode for the fourth season. Their per-episode pay went up an additional $50,000 in each of the following three seasons, culminating in $350,000 per episode in the seventh season.[33][34] In September 2013, Bialik and Rauch renegotiated the contracts they held since they were introduced to the series in 2010. On their old contracts, each was making $20,000–$30,000 per episode, while the new contracts doubled that, beginning at $60,000 per episode, increasing steadily to $100,000 per episode by the end of the contract, as well as adding another year for both.[35]
In the show, the song "Soft Kitty" was described by Sheldon as a song sung by his mother when he was ill. Its repeated use in the series popularized the song.[83] A scene depicting the origin of the song in Sheldon's childhood is depicted in an episode of Young Sheldon, which aired on February 1, 2018. It shows Sheldon's mother Mary singing the song to her son, who is suffering with the flu.[84]
Bert asks for Sheldon's help in a geology research project relating to dark matter. Sheldon secretly agrees, but is too embarrassed to admit he is working with rocks. Bert finds out about this and ends their partnership. After talking with Amy, Sheldon goes to apologize, only to find Leonard has taken his place. Meanwhile, Raj runs into Ruchi again and goes out with her, but she does not believe in romantic love. After Howard and Bernadette tell Raj that he can just have sex with Ruchi, he agrees to keep it casual.

After Sheldon reminds the guys about the time they mined Bitcoin without him, the guys go on a quest to find their suddenly valuable missing cryptocurrency. They realize the currency is on a laptop which Leonard gave to Penny when they dating, which she then gave to her ex-boyfriend Zack. After Leonard and Penny go to Zack's apartment, he shows them a seven-year-old video that Penny recorded on the laptop soon after she broke up with Leonard. Leonard is touched by the video which shows a drunk Penny lamenting the break-up of her relationship with him.
In scenes set at Howard's home, he interacts with his rarely-seen mother (voiced by Carol Ann Susi until her death) by shouting from room to room in the house. She similarly interacts with other characters in this manner.[85] She reflects the Jewish mother stereotype in some ways, such as being overly controlling of Howard's adult life and sometimes trying to make him feel guilty about causing her trouble. She is dependent on Howard, as she requires him to help her with her wig and makeup in the morning. Howard, in turn, is attached to his mother to the point where she still cuts his meat for him, takes him to the dentist, does his laundry and "grounds" him when he returns home after briefly moving out.[86] Until Howard's marriage to Bernadette in the fifth-season finale, Howard's former living situation led Leonard's psychiatrist mother to speculate that he may suffer from some type of pathology,[87] and Sheldon to refer to their relationship as Oedipal.[88] In season 8, Howard's mother dies in her sleep while in Florida, which devastates Howard and Stuart, who briefly lived with Mrs. Wolowitz.
After Sheldon has a food truck moved away from the building, Leonard and Penny are shocked to find he is the leader and sole member of the Tenants' Association for the building. Amy doesn't want to be caught in the middle but secretly suggests they rally support from the other tenants to vote Sheldon out. Nobody else supports Leonard so Amy tells them Sheldon was never added to the lease when he moved across the hall with her. Sheldon fires back with his own legal technicality so Amy is forced to support Leonard. She makes Sheldon happy by saying he can be Leonard's official opposition, making Leonard believe he made a mistake. Meanwhile, Howard and Raj find a drone. Raj returns it to the cute owner Cynthia and gets her number. Unfortunately, Cynthia watches footage of Raj on the drone and is immediately turned off.
Melissa Rauch as Bernadette Rostenkowski-Wolowitz (recurring season 3, starring seasons 4–12):[51] A young woman who initially is a co-worker at The Cheesecake Factory with Penny to pay her way through graduate school, where she is studying microbiology. Bernadette is introduced to Howard by Penny; at first, they do not get along, apparently having nothing in common. They date and later get engaged and married. Although generally a sweet and good-natured person, Bernadette has a short fuse and can be vindictive and lash out when provoked.
Two nerdy physicists share an apartment and an unlikely friendship with their beautiful neighbor with whom one of them is infatuated. Like the universe after the big bang, the show's popularity expanded, thanks to breakout star Jim Parsons, along with the chemistry among the friends and the developing romance between Leonard and Penny. The addition of M (more…)
Star Trek in particular is frequently referenced and Sheldon identifies strongly with the character of Spock, so much so that when he is given a used napkin signed by Leonard Nimoy as a Christmas gift from Penny he is overwhelmed with excitement and gratitude ("I possess the DNA of Leonard Nimoy?!").[73] Star Trek: The Original Series cast member George Takei has made a cameo, and Leonard Nimoy made a cameo as the voice of Sheldon's vintage Mr. Spock action figure (both cameos were in dream sequences). Star Trek: The Next Generation cast members Brent Spiner and LeVar Burton have had cameos as themselves,[74][75] while Wil Wheaton has a recurring role as a fictionalized version of himself. Leonard and Sheldon have had conversations in the Klingon language.
Sara Gilbert as Leslie Winkle (recurring season 1, starring season 2, guest seasons 3, 9):[47][48][49] A physicist who works in the same lab as Leonard. In appearance, she is essentially Leonard's female counterpart and has conflicting scientific theories with Sheldon. Leslie has casual sex with Leonard and later Howard. Gilbert was promoted to a main cast member during the second season but resumed guest star status because producers could not come up with enough material for the character.[47] Gilbert returned to The Big Bang Theory for its 200th episode.[50]
Showrunner Steve Molaro, who took over from Bill Prady with the sixth season, credits some of the show's success to the sitcom's exposure in off-network syndication, particularly on TBS, while Michael Schneider of TV Guide attributes it to the timeslot move two seasons earlier. Chuck Lorre and CBS Entertainment president Nina Tassler also credit the success to the influence of Molaro, in particular the deepening exploration of the firmly established regular characters and their interpersonal relationships, such as the on-again, off-again relationship between Leonard and Penny.[103] Throughout much of the 2012–13 season, The Big Bang Theory placed first in all of syndication ratings, receiving formidable competition from only Judge Judy and Wheel of Fortune (first-run syndication programs). By the end of the 2012–13 television season, The Big Bang Theory had dethroned Judge Judy as the ratings leader in all of syndicated programming with 7.1, Judy descending to second place for that season with a 7.0.[104] The Big Bang Theory did not place first in syndication ratings for the 2013–14 television season, beaten out by Judge Judy.[105]
After Sheldon reminds the guys about the time they mined Bitcoin without him, the guys go on a quest to find their suddenly valuable missing cryptocurrency. They realize the currency is on a laptop which Leonard gave to Penny when they dating, which she then gave to her ex-boyfriend Zack. After Leonard and Penny go to Zack's apartment, he shows them a seven-year-old video that Penny recorded on the laptop soon after she broke up with Leonard. Leonard is touched by the video which shows a drunk Penny lamenting the break-up of her relationship with him.

Like the previous three seasons, the first five episodes aired on Mondays due to CBS' contractual rights to air the Thursday Night Football games. After Thursday Night Football ended, the series returned to a Thursday schedule starting on November 2, 2017. Filming for the eleventh season began on August 15, 2017; it was also announced with the taping report that the premiere for the eleventh season would be titled "The Proposal Proposal". Before the season premiered, five episodes were filmed from August 15 to September 19, 2017.[4]
There was an unaired pilot which CBS did not broadcast. In March 2017, CBS announced that the series was renewed for two more years, leading the show to a total of 12 seasons.[1] The twelfth season premiered on September 24, 2018,[2] and served as the series' final season.[3] During the course of the series, 279 episodes of The Big Bang Theory aired over 12 seasons.
Two physicists from Chicago, Dr. Campbell and Dr. Pemberton, accidentally prove Sheldon and Amy's super-asymmetry theory. This puts them on track for a Nobel Prize, but Leonard points out they tend to go to the experimental scientists who prove a concept instead of theorists like Sheldon who come up with it. Meeting with them, they tell Sheldon they are willing to share the Prize but only three names can be on the submission, and they want to cut Amy out. Amy does not want to prevent Sheldon's lifelong dream, but he goes to President Seibert who agrees to fight for Amy on their behalf. Meanwhile, Bernadette's drug has been approved and she wants to promote Penny to lead the marketing team. Penny resists, knowing Bernadette's attitude at work and doubting her own inexperience to take the responsibility, but Bernadette uses reverse-psychology to get Penny to take the job. Penny mirrors Bernadette's commanding style to get the other employees in line, impressing Bernadette.
In the third-season finale, Raj and Howard sign Sheldon up for online dating to find a woman compatible with Sheldon and discover neurobiologist Amy Farrah Fowler. Like him, she has a history of social ineptitude and participates in online dating only to fulfill an agreement with her mother. This spawns a storyline in which Sheldon and Amy communicate daily while insisting to Leonard and Penny that they are not romantically involved. In "The Agreement Dissection", Sheldon and Amy talk in her apartment after a night of dancing and she kisses him on the lips. Instead of getting annoyed, Sheldon says "fascinating" and later asks Amy to be his girlfriend in "The Flaming Spittoon Acquisition". The same night he draws up "The Relationship Agreement" to verify the ground rules of him as her boyfriend and vice versa (similar to his "Roommate Agreement" with Leonard). Amy agrees but later regrets not having had a lawyer read through it.
The Big Bang Theory started off quietly in Canada, but managed to garner major success in later seasons. The Big Bang Theory is telecast throughout Canada via the CTV Television Network in simultaneous substitution with cross-border CBS affiliates. Now immensely popular in Canada, The Big Bang Theory is also rerun daily on the Canadian cable channel The Comedy Network.

The fourth season's second half began on June 30, 2011. Season 5 began airing on November 3, 2011, at 8:00 p.m. as part of E4's Comedy Thursdays, acting as a lead-in to the channel's newest comedy, Perfect Couples. Episode 19, the highest-viewed episode of the season, attracted 1.4 million viewers.[145] Season 6 premiered on November 15, 2012, with 1.89 million viewers and a further 469,000 on the time shift channel, bringing the total to 2.31 million, E4's highest viewing ratings of 2012, and the highest the channel had received since June 2011. The sixth season returned in mid-2013 to finish airing the remaining episodes.[146] Season 7 premiered on E4 on October 31, 2013 at 8:30pm and hit multiple ratings records this season. The second half of season seven aired in mid 2014.[147] The eighth season premiered on E4 on October 23, 2014 at 8:30 p.m.[148] During its eighth season, The Big Bang Theory shared its 8:30 p.m. time period with fellow CBS comedy, 2 Broke Girls. Following the airing of the first eight episodes of that show's fourth season, The Big Bang Theory returned to finish airing its eighth season on March 19, 2015.[149]


Simon Helberg as Howard Wolowitz:[45] An aerospace engineer who got his Masters at MIT. Howard is Jewish and lived with his mother, Debbie (Carol Ann Susi). Unlike Sheldon, Leonard, Raj, Bernadette and Amy, Howard does not hold a doctorate. He goes into space, training as an astronaut and serving as a payload specialist. Howard initially fancies himself as a womanizer, but he later starts dating Bernadette, and they get engaged and married. Howard also has a tendency to waste money on toys and argues with Bernadette because of his oddly low income as an engineer and her high income as a pharmaceutical biochemist.
×