Initial reception for the series was mixed. The review aggregation website Rotten Tomatoes reported a 52% approval rating for the first season based on reviews from 23 critics, with an average rating of 5.18/10. The website's critical consensus reads, "The Big Bang Theory brings a new class of character to mainstream television, but much of the comedy feels formulaic and stiff."[91] On Metacritic, the season holds a score of 57 out of 100, based on reviews from 23 critics, indicating "mixed or average reviews".[92] Later seasons received more acclaim and in 2013, TV Guide ranked the series #52 on its list of the 60 Best Series of All Time.[93]

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 Melissa Rauch and Mayim Bialik in later seasons also enhanced the stories and relationships of the leads.
"Every heart expanding adventure begins with a single step. This was mine for @bigbangtheory_cbs," Rauch wrote. "My first episode. Or my first 'step-isode' - if you will. The second pic is shortly after I joined the cast (I couldn’t believe I had my very own dressing room)! The friendships and memories that would build from these moments simply overwhelm me."

Kaley Cuoco's life after The Big Bang Theory is going to be animated. Cuoco has signed on to voice and executive produce DC Universe's new Harley Quinn series. She'll play the titular character in the new streaming series targeted toward mature audiences. In 2017, she got the rights to The Flight Attendant, a miniseries based on the book of the same name, which she was poised to star in. The Flight Attendant follows Cassandra Bowden, a flight attendant, who wakes up, hungover, in her hotel room with a dead body next to her. She goes about her day and heads back to New York. is she the killer? That's what she wonders. "This is the first time I have a project that I'm kind of nurturing from the beginning, so it's been a really interesting experience," she told PopSugar in March. "It's got a lot of aspects. It's very sexy. It's a really well-written book, which is why I wanted to option it. I'm ready to bring the character to life."
Wil Wheaton brings William Shatner on his Professor Proton show to meet Sheldon, who gets so excited that he vomits on Shatner. Going to Wil to apologize, he finds Wil hosts a Dungeons & Dragons group with his celebrity friends including Shatner. Finding out Stuart is in the group and never told them, the guys make Stuart panic and quit. Wil secretly invites Leonard who discovers that the group also includes Shatner, Kevin Smith, Joe Manganiello and Kareem Abdul-Jabbar. Leonard tells Penny, who tells Amy and Bernadette, all three women having a crush on Manganiello. Because of that indiscretion, Wil kicks out Leonard and admonishes the guys for using him for his connections, and says that one of the worst things about being a celebrity is not knowing whether someone will like him for himself. To apologize, the guys invite Wil to play D&D with them at Leonard’s apartment, but Wil, secretly in the middle of a game with Penny, Amy and Bernadette and the group, politely turns them down, before allowing the girls to send them a photo of the events as payback.
Leonard and Sheldon are brilliant physicists—geniuses in the laboratory but socially challenged everywhere else. Enter beautiful, street-smart neighbor Penny, who aims to teach them a thing or two about life. Despite their on-again, off-again relationship in the past, Leonard and Penny have finally gotten married. Even Sheldon has found a female companion, entering into a "relationship agreement" with neurobiologist Amy Farrah Fowler, and he recently took their relationship to the next level by marrying her after a long courtship. In their free time, Leonard and Sheldon enjoy fantasy role-playing games with their ever-expanding universe of friends, including fellow scientists Koothrappali, Wolowitz, and Wolowitz’s adorable microbiologist wife, Bernadette, who is adjusting to life with their two children.
However, no legal action was required to end production of the other show: as soon as it became known that the show was unlicensed, the actors quit and the producers canceled it.[209] Dmitriy Tankovich (who plays Leonard's counterpart, "Seva") said in an interview, "I'm upset. At first, the actors were told all legal issues were resolved. We didn't know it wasn't the case, so when the creators of The Big Bang Theory started talking about the show, I was embarrassed. I can't understand why our people first do, and then think. I consider this to be the rock bottom of my career. And I don't want to take part in a stolen show".[210]
"Big Bang" thrived with the addition of new characters, including scientists Amy (Bialik) and Bernadette (Rauch) and comic-book-store owner Stuart (Kevin Sussman), says Helberg, part of the original cast with Galecki, Parsons, Cuoco and Nayyar. (The show eventually spawned a hit prequel spinoff, "Young Sheldon," which heads into its third season in the fall, most likely in the "Big Bang" time slot.)
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.
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.[70] 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.[71] Sheldon and Amy also briefly end their relationship after an argument over which of their fields is superior.[72]
Sheldon and Amy decide on a wedding date of May 12th. They want to have their reception at the Athenaeum at Caltech. While scouting the location, they are shocked to see Leonard and Penny eating there, as Leonard had told Sheldon their application had been denied. In reality, Leonard just wanted a place to avoid Sheldon. Kripke has booked the venue for his birthday party on the same day as the wedding. Leonard cleans radioactive sludge for Kripke to get the date for Sheldon as an apology for lying. Kripke eventually agrees to change the day but when Amy hears he wants to sing at the wedding, she suggests they get married at the Griffith Observatory instead. Meanwhile, Bernadette and Howard are unsure if one of them should quit their job to stay home with the children. Howard volunteers, but when left alone with the children he passes out exhausted, leaving Raj in charge. When Bernadette meets Penny for lunch, she realizes that she loves being at the office again, but doesn't want to leave the children. She and Howard promise to figure it out later after they take a nap.
With Melissa Rauch saying goodbye to Bernadette Rostenkowski-Wolowitz after joining the show in season three and becoming a series regular in season four, she's already begun to carve out new gigs. Not only did her indie film Ode to Joy make its film festival debut this part April, but she has another film, Steven Soderbergh's The Laundromat co-starring none other than Meryl Streep, in post-production, due for a 2019 release. While wrapping up filming on TBBT, she landed her next TV gig, playing Shira, wife of Paul Scheer's Keith on Showtime's recent Wall Street comedy Black Sunday. With the show recently renewed for a second season to debut on the cable net in 2020, it's looking likely she'll be back with greater availability.
Sheldon and Amy are surprised to find that Wil Wheaton's new Professor Proton show is actually very entertaining and that Wil had Howard on as a guest. On Howard's suggestion, Sheldon apologizes to Wil, mending their friendship, and tells him he wants to be on the show; but Wil asks for Amy. Sheldon tells her to do it, but she says she often doesn't do things to avoid upsetting him. Sheldon is horrified when he realises how selfish he has been, especially when he finds out that the men do the same for him. Sheldon encourages Amy to go on the show to inspire girls to pursue science while trying to control his obvious jealousy for her. Meanwhile, Leonard writes a book about a physicist that solves a murder, the protagonist Logan Dean is based on himself. Bernadette points out Logan's mean boss Illsa is similar to Penny, who thinks it is based on Bernadette, though Leonard does not correct her. However, Bernadette tells Penny the truth, upsetting her and making her mad at Leonard. After calling his mother for advice, Leonard learns that Illsa is actually like her; but abandons the book when he realizes he wrote romantic tension into the relationship between the characters.
Sheldon is annoyed that Amy does not have time to work on the super-asymmetry project with him so he talks President Siebert into getting her removed from her own project at the university. Amy is angry at both of them as she wants to still have her own identity outside the marriage. When confronted by Amy, Siebert apologizes to her but states that it will be difficult for the university to give her her project back. After talking with Arthur Jeffries in a dream, Sheldon apologizes to Amy and both of them talk about their fears in their marriage. Meanwhile, Raj does not want to have Howard join him in his show at the planetarium, thinking he'd just use his astronaut status to make it about himself. Raj eventually lets him join in and Raj and Howard spend the whole time complimenting each other, surprising Bernadette, Leonard and Penny.

They are also fans of Star Wars, Battlestar Galactica, and Doctor Who. In the episode "The Ornithophobia Diffusion", when there is a delay in watching Star Wars on Blu-ray, Howard complains, "If we don't start soon, George Lucas is going to change it again" (referring to Lucas' controversial alterations to the films) and in "The Hot Troll Deviation", Katee Sackhoff of Battlestar Galactica appeared as Howard's fantasy dream girl. The characters have different tastes in franchises with Sheldon praising Firefly but disapproving of Leonard's enjoyment of Babylon 5.[76][n 1] With regard to fantasy, the four make frequent references to The Lord of the Rings and Harry Potter novels and movies. Additionally, Howard can speak Sindarin, one of the two Elvish languages from The Lord of the Rings.
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.
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.[70] 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.[71] Sheldon and Amy also briefly end their relationship after an argument over which of their fields is superior.[72]
In the season eight finale, Sheldon and Amy get into a fight about commitment on their fifth anniversary. Amy tells Sheldon that she needs to think about the future of their relationship, unaware that Sheldon was about to propose to her. Season nine sees Sheldon harassing Amy about making up her mind until she breaks up with him. Both struggle with singlehood and trying to be friends for the next few weeks until they reunite in episode ten and have sex for the first time on Amy's birthday.
Leonard's mother Beverly visits, and he is thrilled when she takes an interest in his work. However, when he learns that she is doing research on him for a new parenting book, he is furious. He prepares to tell her how she let him down over the years, but instead chooses to accept and forgive her, and forgive himself for holding onto that resentment for so long. Beverley is touched that he forgave her and they share a genuine hug. Meanwhile, Anu gets a job offer in London. Raj prepares to fly out and propose to her, ready to follow her if she accepts. Howard stops Raj at the airport, saying there is a better match out there for him, convincing Raj to return home. Stuart and Denise are bothered by her creepy roommate Mitch, while Bernadette and Howard are tired of Denise constantly staying overnight with Stuart at their house. Stuart says he is ready to move in with Denise, and they say they love each other while convincing Mitch to move out.
Sheldon is annoyed that Amy does not have time to work on the super-asymmetry project with him so he talks President Siebert into getting her removed from her own project at the university. Amy is angry at both of them as she wants to still have her own identity outside the marriage. When confronted by Amy, Siebert apologizes to her but states that it will be difficult for the university to give her her project back. After talking with Arthur Jeffries in a dream, Sheldon apologizes to Amy and both of them talk about their fears in their marriage. Meanwhile, Raj does not want to have Howard join him in his show at the planetarium, thinking he'd just use his astronaut status to make it about himself. Raj eventually lets him join in and Raj and Howard spend the whole time complimenting each other, surprising Bernadette, Leonard and Penny.
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.
Through the use of his vanity cards at the end of episodes, Lorre alleged that the program had been plagiarized by a show produced and aired in Belarus. Officially titled Теоретики (The Theorists), the show features "clones" of the main characters, a similar opening sequence, and what appears to be a very close Russian translation of the scripts.[207] Lorre expressed annoyance and described his inquiry with the Warner Bros. legal department about options. The television production company and station's close relationship with the Belarus government was cited as the reason that any attempt to claim copyright infringement would be in vain because the company copying the episodes is operated by the government.[208]
As the theme of the show revolves around science, many distinguished and high-profile scientists have appeared as guest stars on the show. Famous astrophysicist and Nobel laureate George Smoot had a cameo appearance in the second season.[56] Theoretical physicist Brian Greene appeared in the fourth season, as well as astrophysicist, science populizer, and physics outreach specialist Neil deGrasse Tyson, who also appeared in the twelfth season.
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 Melissa Rauch and Mayim Bialik in later seasons also enhanced the stories and relationships of the leads.
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.
×