The Big Bang Theory

"The Big Bang Theory" is an American television sitcom created by Chuck Lorre and Bill Prady for CBS. It aired from September 24, 2007, to May 16, 2019, running for 12 seasons and 279 episodes.

The show originally centered on five characters living in Pasadena, California: Leonard Hofstadter (Johnny Galecki) and Sheldon Cooper (Jim Parsons), both physicists at the California Institute of Technology, who share an apartment; Penny (Kaley Cuoco), a waitress and aspiring actress who lives across the hall; and Leonard and Sheldon's similarly geeky and socially awkward friends and coworkers, aerospace engineer Howard Wolowitz (Simon Helberg) and astrophysicist Raj Koothrappali (Kunal Nayyar). Over time, supporting characters were promoted to starring roles, including neuroscientist Amy Farrah Fowler (Mayim Bialik), microbiologist Bernadette Rostenkowski (Melissa Rauch), and comic book store owner Stuart Bloom (Kevin Sussman).

The series was filmed in front of a live audience and produced by Chuck Lorre Productions, with Warner Bros. Television handling distribution. While the first season received mixed reviews, critical reception improved in subsequent seasons. Seven seasons ranked within the top ten of the final-season ratings, and the series reached the No. 1 spot in its eleventh season. It 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 Parsons, totaling seven Emmy Awards from 46 nominations. Parsons also won the Golden Globe for Best Actor in a Television Comedy Series in 2011.

The success of The Big Bang Theory launched a multimedia franchise. A prequel series focusing on Parsons' character Sheldon Cooper, Young Sheldon, aired from 2017 to 2024, with Parsons narrating as the adult Sheldon. The third series in the franchise, a sequel to Young Sheldon titled Georgie & Mandy's First Marriage, premiered in October 2024 and follows Sheldon's older brother, Georgie, and his wife, Mandy. A fourth series, following Stuart Bloom and his girlfriend Denise, along with geologist Bert Kibbler titled Stuart Fails to Save the Universe, is currently in development for HBO Max.

Plot

The show follows the lives of four friends living in Pasadena, California: Leonard and Sheldon, who are scientists; Penny, who works in a diner and wants to act; and their friends Howard and Raj. The story starts with Leonard falling for Penny, but she dates other people at first. Over time, the friends share their love for science, comic books, and games, even though they sometimes act in funny ways.

As the show goes on, new friends join, like Amy and Bernadette. Sheldon and Amy start with just talking, but their relationship grows. Howard and Bernadette get married, and Leonard and Penny eventually get back together and marry too. In the end, the friends achieve their dreams—Penny becomes pregnant, and Sheldon and Amy win a big science prize, showing how their friendships helped them succeed.

Cast and characters

Main article: List of The Big Bang Theory franchise characters

See also: List of The Big Bang Theory guest stars

The show features several main characters who live in Pasadena, California. Leonard Hofstadter and Sheldon Cooper are both physicists who share an apartment. Leonard loves video games and comic books, while Sheldon is very clever but finds social situations tricky. Penny is their neighbor who works at a restaurant and dreams of acting. Howard and Raj are also friends of Leonard and Sheldon, each with their own unique personalities and backgrounds. Over time, new characters like Amy and Bernadette join the group, becoming good friends and sometimes romantic partners. The show follows their adventures as they navigate friendship, love, and their shared love of science and pop culture.

Episodes

Main article: List of The Big Bang Theory episodes

Production

The show's first episode aired on September 24, 2007. This was the second pilot made for the show. A different pilot was made for the 2006–07 television season but was never shown. The original pilot had some different characters, but kept Leonard and Sheldon, who are named after a famous TV producer, director, and actor.

The creators changed the pilot and made a new one, bringing in more cast members. The show started with 13 episodes and was later picked up for a full season. It was filmed in front of a live audience and produced by Chuck Lorre Productions and Warner Bros. Television. Production stopped for a time due to a strike but later continued.

Science consultants

A physics and astronomy professor from the University of California, Los Angeles checked the scripts and helped with science facts. He made sure the science looked right, especially on the whiteboards in the characters' apartment.

Theme song

A Canadian band wrote and recorded the show's theme song about the universe and Earth. The band's singer was asked to write the song after improvising a rap about the universe at a concert.

Actors' salaries

The main actors started with high salaries, which increased each season. By later seasons, the main stars were earning around $1 million per episode. Some actors renegotiated their contracts to earn more, and by the end, all main cast members were earning high salaries.

Recurring themes and elements

Science

The show often focuses on science, especially physics. The main characters work at Caltech and have jobs related to science. They talk about scientific ideas and news, and they joke about science topics.

Science sometimes affects the characters' personal lives. For example, one character breaks up with Leonard because he supports a science idea that she does not like. Another time, Leonard goes away for three months for a science trip, which affects his relationship with Penny.

Many famous scientists have appeared on the show as guests. These include Astrophysicist and Nobel laureate George Smoot, Theoretical physicist Brian Greene, and Cosmologist Stephen Hawking.

"Nerd" media

The characters love science fiction, fantasy, comic books, and collecting memorabilia. They often talk about shows like Star Trek, Star Wars, and Doctor Who, and they enjoy games like World of Warcraft and Halo.

Wednesday nights are special because that is when new comic books are released. The characters sometimes dress up as famous characters from movies and TV shows.

Leonard and Penny's relationship

Leonard and Penny have an interesting relationship. Leonard likes Penny from the start, but she dates other people at first. Later, they start dating, but they break up for a while. Eventually, they get back together, get married, and live happily. By the end of the show, Penny decides she wants to have children after all.

Sheldon and Amy's relationship

Sheldon and Amy meet through an online dating service. At first, they act like they are not interested in each other, but later they start dating. They have a special "agreement" about their relationship. Over time, they fall in love, get married, and live together.

"Soft Kitty"

Sheldon sings a song called "Soft Kitty" that his mother used to sing to him when he was sick. The song becomes popular on the show.

Howard's mother

Howard's mother is a character who often shouts from room to room in Howard's house. She is very controlling and depends on Howard for many things. Howard feels very close to her, and he is sad when she passes away.

Apartment building elevator

The elevator in the apartment building where Leonard, Sheldon, Penny, and Amy live is broken for most of the show. This means the characters have to use the stairs to get to their apartments. In one episode, we learn that Leonard broke the elevator while experimenting with rocket fuel. Near the end of the show, the elevator is fixed, but Sheldon is not too upset because things return to how they were before.

Vanity cards

Like many shows created by Chuck Lorre, The Big Bang Theory ends with a special card created by Lorre. These cards are kept on Lorre's website. The last card for the show simply says "The End".

Release

Broadcast

The Big Bang Theory started in the United States on September 24, 2007, on CBS. It also began airing in Canada on CTV around the same time. In the United Kingdom, the show debuted on E4 and Channel 4 in February 2008. In Australia, the Seven Network and 7mate showed the first seven seasons from October 2015, with Nine Network getting seasons nine and ten.

Syndication and streaming

In May 2010, the show was picked up for syndication, mainly on Fox’s stations and TBS. On September 17, 2019, HBO Max got the rights to stream the show in the U.S. In December 2024, Paramount Global got rights to show it on Nick at Nite and MTV. Starting in 2025, it became available on Disney+ in some places.

Home media

The first two seasons were released only on DVD in 2008 and 2009. From the third season in 2010, both DVD and Blu-ray versions were released each year. In 2012, the first two seasons were also released on Blu-ray.

Reception

Critical response

At first, people had mixed feelings about the show, but it later gained more positive reviews. The website Rotten Tomatoes gave it an 81% approval rating from critics. On Metacritic, the series scored 61 out of 100, based on reviews from 27 critics, showing generally good reviews. In 2013, TV Guide placed the series at #52 on its list of the 60 Best Series of All Time.

American ratings

The Big Bang Theory started slowly in ratings, not making the top 50 in its first season (ranking 68th), and ranking 40th in its second season. However, when the third season began on September 21, 2009, it became CBS's highest-rated show that evening for adults aged 18–49, with 12.83 million viewers. The show moved to Thursdays at 8:00 ET in the 2010–2011 season, competing with other popular shows. By its fourth season, it became television's highest-rated comedy. The sixth season had some of the highest-rated episodes ever, with over 20 million viewers for certain episodes. The show's success was also helped by its airing on different channels and times.

UK distribution and ratings

The show debuted in the United Kingdom on Channel 4 on February 14, 2008, and later aired on E4. It became very popular on E4, with many viewers tuning in each week. The show's ratings kept growing over the seasons, making it one of E4's most-watched programs.

Canadian ratings

The Big Bang Theory started with moderate success in Canada but became very popular later on. It aired on the CTV Television Network and became the most-watched entertainment show in Canada.

Accolades

Main article: List of awards and nominations received by The Big Bang Theory

The show won several awards over the years. Jim Parsons, who played Sheldon, won many acting awards, including Emmy Awards and a Golden Globe. The show also won People's Choice Awards and other recognitions.

Merchandise

In 2014, a fun idea for a Lego set showing the living room from the show with the main characters as tiny Lego figures got enough votes to become real. Lego made the set and it came out in August 2015. Before that, there was a special sale at San Diego Comic-Con.

Offshoots

Plagiarized series

Chuck Lorre claimed that a show in Belarus copied The Big Bang Theory in 2010. The show, called The Theorists, used similar characters and stories. When the creators of The Big Bang Theory talked about it, the actors and producers of the Belarus show stopped making it.

Spin-offs

Young Sheldon

A spin-off called Young Sheldon started in 2017. It shows Sheldon Cooper as a young boy living in East Texas. The show follows Sheldon's life with his family. Jim Parsons, who plays adult Sheldon, narrates the stories.

Georgie & Mandy's First Marriage

In 2024, a new spin-off called Georgie & Mandy's First Marriage began. It focuses on Sheldon’s brother Georgie and his wife Mandy.

Stuart Fails to Save the Universe

In 2023, plans for another spin-off were announced. Called Stuart Fails to Save the Universe, it stars Stuart Bloom. The story involves Stuart trying to fix a problem he caused with a device made by Sheldon and Leonard.

Television special

On May 16, 2019, a special called Unraveling the Mystery: A Big Bang Farewell aired after the final episode of The Big Bang Theory. It looked back at the show with Johnny Galecki and Kaley Cuoco.