After the strike ended, the show was picked up for a second season, airing in the 2008–2009 season, premiering in the same time slot on September 22, 2008. With increasing ratings, the show received a two-year renewal through the 2010–11 season in 2009. In 2011, the show was picked up for three more seasons. In March 2014, the show was renewed again for three more years through the 2016–17 season. This marked the second time the series gained a three-year renewal. In March 2017, the series was renewed for two additional seasons, bringing its total to 12, and running through the 2018–19 television season.
"The Locomotive Manipulation" is the first episode in which Sheldon initiates a kiss with Amy. Although initially done in a fit of sarcasm, he discovers that he enjoys the feeling. Consequently, Sheldon slowly starts to open up over the rest of the season, and starts a more intimate relationship with Amy. However, in the season finale, Sheldon leaves temporarily to cope with several changes and Amy becomes distraught. However, in "The Prom Equivalency", he hides in his room to avoid going to a mock prom reenactment with her. In the resulting stand-off, Amy is about to confess that she loves Sheldon, but he surprises her by saying that he loves her too. This prompts Amy to have a panic attack.
Turning to total viewers, “Manifest” was the biggest gainer overall, on average adding 6.1 million viewers per episode. ABC’s “The Good Doctor” was second with an average viewer lift of just under 6 million. “New Amsterdam” (5.2 million viewer lift) and “A Million Little Things” (3.5 million viewer lift) were also among the top gainers in this measure, as was ABC’s “Whiskey Cavalier” (3.2 million viewer lift).
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. The twelfth season premiered on September 24, 2018, and served as the series' final season. During the course of the series, 279 episodes of The Big Bang Theory aired over 12 seasons.
The sixth season boasts some of the highest-rated episodes for the show so far, with a then-new series high set with "The Bakersfield Expedition", with 20 million viewers, a first for the series, which along with NCIS, made CBS the first network to have two scripted series reach that large an audience in the same week since 2007. In the sixth season, the show became the highest rated and viewed scripted show in the 18–49 demographic, trailing only the live regular NBC Sunday Night Football coverage, and was third in total viewers, trailing NCIS and Sunday Night Football. Season seven of the series opened strong, continuing the success gained in season six, with the second episode of the premiere, "The Deception Verification", setting the new series high in viewers with 20.44 million.
In the episode "The Launch Acceleration", Amy tries to use her "neurobiology bag of tricks" to increase the attraction between herself and Sheldon. In the final fifth-season episode "The Countdown Reflection", Sheldon takes Amy's hand as Howard is launched into space. In the sixth season first episode "The Date Night Variable", after a dinner in which Sheldon fails to live up to this expectation, Amy gives Sheldon an ultimatum that their relationship is over unless he tells her something from his heart. Amy accepts Sheldon's romantic speech even after learning that it is a line from the first Spider-Man movie. In "The Cooper/Kripke Inversion" Sheldon states that he has been working on his discomfort about physical contact and admits that "it's a possibility" that he could one day have sex with Amy. Amy is revealed to have similar feelings in "The Love Spell Potential". Sheldon explains that he never thought about intimacy with anyone before Amy.
Sheldon's mother Mary refuses to attend his wedding unless he invites his older brother George, with whom he is no longer speaking. Sheldon and Leonard fly to Texas to talk to George, who now owns a chain of tire stores. He refuses to attend and later explains to Leonard and Sheldon that the family sacrificed a lot to fund Sheldon's education, and he was stuck caring for their mother and sister Missy after their father died while Sheldon was in college. Sheldon never thanked him for this. Leonard takes George back to the hotel room where Sheldon apologizes for what he did and the brothers reconcile. George agrees to attend the wedding. Meanwhile, Howard and Bernadette's children contract pinkeye, infecting everyone except Penny, much to Amy's fury.
Howard and Bernadette learn their second child will be a boy, leading Howard to doubt whether he can be a good father to a son. He and Sheldon go out in the desert to test launch a model rocket, but it explodes, causing him further doubt. On the way home, Howard does a good job coaching Sheldon to drive them home, for which Sheldon tells him he will be a good teacher to his son. Leonard's mother Beverly begins talking to Penny as a friend and confidant, troubling Leonard, especially when he learns that Beverly told Penny that she was proud of her, a level of praise she never bestowed upon Leonard himself. When Leonard confronts Beverly, he is touched when she says that of all of her children's spouses, Penny is the one by whom she is most impressed and that, for this, she is indeed proud of him. Meanwhile, Raj helps Bernadette turn baby girl clothes into boy ones.
On March 13, 2017, CBS ordered the spin-off Young Sheldon series. Jon Favreau directed and executive produced the pilot. Created by Lorre and Molaro, the series follows 9-year-old Sheldon Cooper as he attends high school in East Texas. Alongside Armitage as 9-year-old Sheldon Cooper and Perry as Mary Cooper, Lance Barber stars as George Cooper, Sheldon's father; Raegan Revord stars as Missy Cooper, Sheldon's twin sister; and Montana Jordan as George Cooper Jr., Sheldon's older brother. Jim Parsons reprises his role as adult Sheldon Cooper, as narrator for the series. Parsons, Lorre, Molaro and Todd Spiewak will also serve as executive producers on the series, for Chuck Lorre Productions, Inc. in association with Warner Bros. Television. The show's pilot episode premiered on September 25, 2017. Subsequent weekly episodes began airing on November 2, 2017 following the broadcast of the 237th episode of The Big Bang Theory.
When Raj misses out on a job at the planetarium, his father says he has no confidence because Howard always makes fun of him. Raj distances himself from Howard and later gets the job. Howard is hurt by this (even after apologizing to him) and tries to make amends with Raj after his first performance at the planetarium but, when he sees him get a date, he leaves without speaking to him, thinking that the latter's life is better without him. Meanwhile, Sheldon and Amy try randomly dividing up wedding tasks, but they keep arguing. The only thing they can agree on is to get married, so they decide to just get married at City Hall. However, Sheldon decides that he wants a first dance with his new wife and they go home to plan their wedding.
^ Kondolojy, Amanda (November 8, 2013). "Thursday Final Ratings: 'Elementary', 'Scandal', 'The Vampire Diaries', & 'The Big Bang Theory' Adjusted Up; 'The Voice', 'The Millers', 'Sean Saves the World', 'Parenthood', & 'The Michael J Fox Show' Adjusted Down". TV by the Numbers. Archived from the original on November 8, 2013. Retrieved November 8, 2013.
^ Jump up to: a b Kondolojy, Amanda (October 12, 2014). "'Gotham' Has Biggest Adults 18–49 Ratings Increase; 'Gotham' & 'Red Band Society' Top Percentage Gains & 'How To Get Away With Murder' Tops Viewer Gains in Live +7 Ratings for Week Ending September 28". TV by the Numbers. Archived from the original on October 16, 2014. Retrieved October 13, 2014.
Sheldon and Amy recruit Leonard to research and write citations for their paper on super asymmetry. While working in the campus library, Leonard and Raj discover a Russian paper that asserts that super asymmetry has no merit. Reluctantly, Leonard shares the news with Sheldon and Amy, who fall into a depressive state and do not leave their apartment. Meanwhile, Bernadette asks Denise to teach her how to play Fortnite: Battle Royale so that she can beat Howard. Despite losing to Howard in a rematch after all of her training, Bernadette revels in beating a disinterested Penny.
Leonard tells Zack and Marissa he will father their child, but Penny tries to seduce him despite knowing he has to be abstinent for a few days. Her visiting father, Wyatt, points out her actions suggest she is more conflicted over having kids than she lets on, which she admits. Wyatt says he will support her no matter what. Meanwhile, Sheldon and Amy warn that he will not be allowed to raise a child that is not his. Leonard decides not to go through with it; he tells Zack to have Sheldon be the donor, but Amy forbids it. Meanwhile, Howard turns Raj's cancelled bachelor party into a couples' trip into a zero-gravity aircraft, though he's convinced that Bernadette would hate it. Bernadette tries to get out of it so Howard sits out, forcing Bernadette to go through with it just to prove him wrong, though she does not enjoy it.
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. 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. 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, and Sheldon to refer to their relationship as Oedipal. In season 8, Howard's mother dies in her sleep while in Florida, which devastates Howard and Stuart, who briefly lived with Mrs. Wolowitz.
Live+7 data is currently available only through May 5, but the top dogs will likely see little change once the final numbers are in for the traditional September-May season. The top gainer in adults 18-49 was NBC’s “This Is Us” with an average lift of 1.8 ratings points. The number two spot was a tie between CBS’ “Big Bang Theory” and NBC’s “Manifest,” with both of those shows adding 1.5 ratings points on average. These numbers do not include “Big Bang Theory’s” series finale, however, which pulled in a 3.1 rating and 18 million viewers in Live+Same Day alone on May 16.
Howard and Raj are still fighting, so Howard dis-invites Raj to Halley's birthday party. However, when Stuart pulls out as party planner at the last minute, Raj agrees to plan the party, which doesn't turn out too well due to Halley being asleep, Bernadette being on bed rest, and no people turning up. When Howard and Raj get into a shoving match in the party's bounce house, they end up letting out their frustrations, but also having fun and reconciling. Leonard is depressed upon receiving his successful brother's Christmas card and attempts to make a list of what he and Penny accomplished this year, not coming up with much. This prompts them to think about their plans for the future, so they decide to go on trips and achieve more out of life together before starting a family. Sheldon cooks Amy a Little House on the Prairie-themed birthday dinner, which gives them both food poisoning. They eventually recover enough to attend Halley's birthday party with the others, where they have fun in the bouncy castle and then have sex in Howard and Bernadette's house.
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.
The Big Bang Theory signs off for good on Thursday, May 16, meaning that there's only one last bazinga left in the pipeline before we're forced to say farewell to Sheldon, Leonard, Penny, and the gang after 12 laugh-filled seasons. And while there's still a few questions left to be answered by the big one-hour series finale—Will the elevator ever be fixed? And will we ever learn Penny's maiden name?—there's a bigger one looming for when the credits roll and it's all over.
Sheldon cannot find the perfect wedding date and begins talking in his sleep, adopting the persona of a laid-back person who goes with the flow. Amy and Penny believe that his subconscious mind is trying to tell him to be more relaxed; his attempt to be so while wearing flip-flops ends in disaster. He decides to leave all the wedding planning to Amy while he wears a Star Trek uniform underneath his tuxedo. Meanwhile, Raj and Stuart both become interested in Bernadette's new coworker Ruchi. While she likes them both as friends, she does not want a relationship with anyone.
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. 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.
By season seven, Galecki, Parsons, and Cuoco were also receiving 0.25% of the series' back-end money. Before production began on the eighth season, the three plus Helberg and Nayyar, looked to renegotiate new contracts, with Galecki, Parsons, and Cuoco seeking around $1 million per episode, as well as more back-end money. Contracts were signed in the beginning of August 2014, giving the three principal actors an estimated $1 million per episode for three years, with the possibility to extend for a fourth year. The deals also include larger pieces of the show, signing bonuses, production deals, and advances towards the back-end. Helberg and Nayyar were also able to renegotiate their contracts, giving them a per-episode pay in the "mid-six-figure range", up from around $100,000 per episode they each received in years prior. The duo, who were looking to have salary parity with Parsons, Galecki, and Cuoco, signed their contracts after the studio and producers threatened to write the characters out of the series if a deal could not be reached before the start of production on season eight. By season 10, Helberg and Nayyar reached the $1 million per episode parity with Parsons, Galecki, and Cuoco, due to a clause in their deals signed in 2014.