Amy enthusiastically accepts Sheldon's marriage proposal. However, when dining with Amy's colleagues later that night, Sheldon is offended that they are more impressed with Amy's work than his own. With help from Stephen Hawking, Sheldon later comes to grips with the fact that he will not always be the center of attention in the marriage. Bernadette is shocked to realize that she is pregnant again. She and Howard are not thrilled at the idea of having another baby so soon after their first. They attempt to convince Leonard and Penny to have a child as well, but are rebuffed.
Although earlier this season Penny (Kaley Cuocuo) told her husband Leonard (Johnny Galecki) that she never wanted kids, part two of the finale reveals that she is pregnant. But when Sheldon dismisses her announcement, Leonard angrily says “to hell with” his Nobel Prize. When his friends threaten to leave at his poor treatment of them, Sheldon takes time to self reflect.
It’s no secret that the cast of The Big Bang Theory gets paid out for every episode. But, who is the richest Big Bang Theory cast member? As it turns out, the show’s lead, Jim Parsons is the highest earning actor on the hit television series. The actor, who plays Sheldon Cooper, is worth $70 million and brings in $900,000 per episode on The Big Bang Theory (he and some of his castmates made $1 million per episode, but took a $100,000 pay cut so some of the other supporting roles could get a raise).
Sheldon and Amy struggle to choose a best man and maid of honor from their friends. They secretly decide to test and score them, allowing everyone to have an equal shot at either role. Once the gang finds out, none of them apart from Bernadette and Stuart want to be in the wedding. Sheldon settles for Stuart as best man but, once Leonard tells Sheldon that, as the groom, the decision is his alone, he picks Leonard. Amy is set to call Bernadette but, once Penny realizes Amy is her best friend, she immediately pitches herself for the position and Amy enthusiastically chooses her. Amy later makes Penny tell Bernadette the bad news.
Raj hooks up with a recently separated woman, Nell, after one of his lectures at the planetarium. Her husband, Oliver, confronts Raj at the planetarium and then breaks down over the end of his marriage. After comforting Oliver, Raj talks to Nell and convinces her to give her husband another chance. Meanwhile, after diving once again into string theory and sprawling his work across his and Amy's apartment, Sheldon approaches a reluctant Leonard and Penny and convinces them to let him use his old room to study for a three-day trial period with an agreement to be quiet and stay out of their way. Sheldon surprisingly sticks to this agreement, being a reasonably good guest, which shockingly frustrates Leonard to no end. After Leonard lets out his frustrations, Sheldon then renegotiates the guest tenancy agreement for an extra few days and resumes being his normal demanding self, much to Leonard's relief.
With Leonard, Howard, Raj, and Amy accomplishing so much on their respective projects, Sheldon is forced to admit he has nothing important upon which to work. He makes Amy leave the apartment for a few days so he can focus, but cannot come up with any ideas and calls his mother as a distraction. Leonard and Amy have fun recreating experiments from when they were growing up, boring Penny, so she eats with Sheldon as he mulls over his scientific studies. Penny helps him realize that his study of dark matter is his rebound science from string theory, which Sheldon admits he never truly disregarded, but explaining string theory to her inspires Sheldon, helping him discover a potential breakthrough in the field. Meanwhile Howard is too busy with his family to be in the band with Raj, so Raj brings in Bert. But, when Howard annoys Bernadette by writing an astronaut-themed musical while she is on bed-rest, she makes him rejoin the band. The three are poorly received at a Bar mitzvah after singing Bert's original song about the boulder from Indiana Jones .
Filming proceeds smoothly – makeup artists do touch-ups, a prop master replenishes the pickle supply – with humor and camaraderie between takes. When a reshoot is needed because Simon Helberg, who plays Howard, held his napkin in the wrong hand, Kaley Cuoco, who plays Penny, lifts her food box high and mockingly asks, “Does it go over my head? I don’t remember.”
The show was filmed in front of a live audience and was produced by Warner Bros. Television and Chuck Lorre Productions. The Big Bang Theory received mixed reviews from critics throughout its first season, but reception was more favorable in the second and third seasons. Later seasons saw a return to a lukewarm reception, with the show being criticized for a decline in comedic quality. Despite the mixed reviews, seven seasons of the show have ranked within the top ten of the final television season ratings, ultimately reaching the no. 1 spot in its eleventh season. The show was nominated for the Emmy Award for Outstanding Comedy Series from 2011 to 2014 and won the Emmy Award for Outstanding Lead Actor in a Comedy Series four times for Jim Parsons. It has so far won seven Emmy Awards from 46 nominations. Parsons also won the Golden Globe for Best Actor in a Television Comedy Series in 2011. The series has so far won 56 awards from 216 nominations. It has also spawned a prequel series in 2017 based on Parsons' character, Sheldon Cooper, named Young Sheldon, which also airs on CBS.
Penny, who admits to missing Leonard in "The Roommate Transmogrification", accepts his request to renew their relationship in "The Beta Test Initiation". After Penny suggests having sex in "The Launch Acceleration", Leonard breaks the mood by proposing to her. Penny says "no" but does not break up with him. She stops a proposal a second time in "The Tangible Affection Proof". In the sixth-season episode, "The 43 Peculiarity", Penny finally tells Leonard that she loves him. Although they both feel jealousy when the other receives significant attention from the opposite sex, Penny is secure enough in their relationship to send him off on an exciting four-month expedition without worrying in "The Bon Voyage Reaction". After Leonard returns, their relationship blossoms over the seventh season. In the penultimate episode "The Gorilla Dissolution", Penny admits that they should marry and when Leonard realizes that she is serious, he proposes with a ring that he had been saving for years. Leonard and Penny decide to elope to Las Vegas in the season 8 finale, but beforehand, wanting no secrets, Leonard admits to kissing another woman, Mandy Chow (Melissa Tang) while on an expedition on the North Sea. Despite this, Leonard and Penny finally elope in the season 9 premiere.
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.
When Leonard receives a braggy Christmas letter from his brother, he feels bad about how little he and Penny have achieved in the past year. Leonard wonders if he and Penny should be thinking about the next step after two years of marriage, like buying a house or having a baby. Penny tells him she wants to do all those things someday, but she has a bunch of stuff she would like to do first.
^ From the eighth season onward, episodes of each season initially aired on Monday nights, before later returning to the Thursday night slot for the rest of the season. The eighth and ninth seasons returned on the seventh episode, the tenth and eleventh seasons on the sixth episode, and the twelfth season on the second episode.
Science has also interfered with the characters' romantic lives. Leslie breaks up with Leonard when he sides with Sheldon in his support for string theory rather than loop quantum gravity. When Leonard joins Sheldon, Raj, and Howard on a three-month Arctic research trip, it separates Leonard and Penny at a time when their relationship is budding. When Bernadette takes an interest in Leonard's work, it makes both Penny and Howard envious and results in Howard confronting Leonard, and Penny asking Sheldon to teach her physics. Sheldon and Amy also briefly end their relationship after an argument over which of their fields is superior.