You can read them in the folloowing list: 1. The Big Bang Theory (also abbreviated as TBBT) is an American sitcom created by Chuck Lorre and Bill Prady, both of whom serve as executive producers on the show along with Steven Molaro. All three also serve as head writers.
2. The show premiered on CBS on September 24, 2007.
3. The ninth season premiered on September 21, 2015
4. The show is primarily centered on five characters living in Pasadena, California: Leonard Hofstadter and Sheldon Cooper, both physicists at Caltech, who share an apartment; Penny, a waitress and aspiring actress who later becomes a pharmaceutical representative, and who lives across the hall; and Leonard and Sheldon’s similarly geeky and socially awkward friends and co-workers, aerospace engineer Howard Wolowitz and astrophysicist Raj Koothrappali.
5. The geekiness and intellect of the four guys is contrasted for comic effect with Penny’s social skills and common sense.
6. Over time, supporting characters have been promoted to starring roles: Bernadette Rostenkowski, Howard’s girlfriend (later his wife), a microbiologist and former part-time waitress alongside Penny; neuroscientist Amy Farrah Fowler, who joins the group after being matched to Sheldon on a dating website (and later becomes Sheldon’s girlfriend); Stuart Bloom, the cash-strapped owner of the comic book store the characters often visit, who, in season 8, moves in with Howard’s mother; and Emily Sweeney, a dermatologist who dates Raj and has a fascination with the macabre.
7. The show’s initial pilot, developed for the 2006–07 television season, was substantially different from its current form. The only characters from the initial pilot that were kept for the reshot pilot for the series were Leonard and Sheldon (portrayed by Johnny Galecki and Jim Parsons, respectively, and named after Sheldon Leonard). Althea (Vernee Watson), a character featured in the first episode, was also featured in the initial pilot and brought to the reshot pilot.
8. The cast was rounded off by two female leads: Canadian actress Amanda Walsh as Katie, “a street-hardened, tough-as-nails woman with a vulnerable interior” whom the boys meet after she breaks up with her boyfriend and invite to live in their apartment (Katie was replaced by Penny, portrayed by Kaley Cuoco, in the second pilot); and Iris Bahr as Gilda, a scientist colleague and friend of the boys who was threatened by Katie’s presence.
9. The initial pilot used Thomas Dolby’s hit “She Blinded Me with Science” as theme music. The test audiences reacted negatively to Katie, but they liked Sheldon and Leonard.
10. The first and second pilots of The Big Bang Theory were directed by James Burrows, who did not continue with the show. The reworked second pilot led to a 13-episode order by CBS on May 14, 2007. Prior to its airing on CBS, the pilot episode was distributed on iTunes free of charge. The show premiered on September 24, 2007, and was picked up for a full 22-episode season on October 19, 2007. The show is filmed in front of a live audience, and is produced by Warner Bros.
11. Production was halted on November 6, 2007, due to the Writers Guild of America strike. Nearly three months later, on February 4, 2008, the series was temporarily replaced by a short-lived sitcom, Welcome to the Captain. The series returned on March 17, 2008 in an earlier time slot and ultimately only 17 episodes were produced for the first season. 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.
12. 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. Therefore, the series will at least reach 10 seasons. This marks the second time the series has gained a three-year renewal.
13. Several of the actors in The Big Bang Theory previously worked together on Roseanne including Johnny Galecki, Sara Gilbert, Laurie Metcalf (who plays Sheldon’s mother, Mary Cooper) and Meagen Fay (who plays Bernadette’s mother). Additionally, Lorre was a writer on the series for several seasons.
14. 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. By season seven, the three were also receiving 0.25 point of the series’ backend money.
15. The Canadian alternative rock band Barenaked Ladies wrote and recorded the show’s theme song, which describes the history and formation of the universe and the Earth. Ed Robertson, co-lead singer and lead guitarist in the band, was asked by Lorre and Prady to write a theme song for the show after the producers attended one of the band’s concerts in Los Angeles.
16. As the theme of the show revolves around science, many distinguished and high profile scientists have appeared as guest stars on the show.
17. Most of the time, Leonard has no lenses in his glasses.
18. Recurring guest Mayim Bialik is the only cast member to have a PhD. In 2008, she completed her neuroscience studies. She earned her Ph.D. in Neural Biology.
19. The two main characters (Sheldon Cooper and Leonard Hofstadter) are named after late television producer Sheldon Leonard.
20. When Sheldon plays the theremin, (which is widely regarded as one of the hardest instruments to play) that is actually Jim Parsons playing the theremin.
21. Jim Parsons audition for the role of Dr. Sheldon Cooper was so good that creator Chuck Lorre immediately asked Parsons to come in for a second one, because Lorre wanted to be 100% sure Parsons was as brilliant as he seemed. After the 2nd audition went perfectly, Lorre cast Parsons on the spot.
22. Raj’s inability to talk to women except when drunk is based on an old co-worker of executive producer Bill Prady when he worked at a computer company.
23. Kaley Cuoco missed filming two episodes of season four because of a broken leg that was the result of a horseback-riding accident. In her first appearance following the accident, she was filmed standing behind a counter.
24. During the third season, the producers became aware of a series called “The Theorists,” produced and broadcast in the country of Belarus, that was a virtual copy of The Big Bang Theory (2007). Legal action over copyright infringement would have been futile, since the production company was pretty much owned by the Belarus government. However, a lawsuit turned out not to be necessary, because when word got out that the show was a rip-off, the actors quit and the show was immediately canceled.
25. Even though Jim Parsons’ character Sheldon Cooper is a huge Star Trek (1966) fan, Jim himself has never seen the show. The same is true for Dr. Who (1963).
26. Penny has been using the same purse since S1/Ep02.
27. The actors learned to actually play their instruments for the show. (Amy plays harp, Sheldon plays Theremin and recorder, and Leonard plays Cello)
28. Although Sheldon does not drive, Jim Parsons gets motion sickness from riding in cars, and prefers to drive them
29. Sheldon’s soothing song, “Soft Kitty”, is based on an Australian children’s song from Executive Producer Bill Prady’s daughter’s pre school.
30. In fall 2010, Kaley Cuoco revealed to CBS’s Watch! Magazine’s Behind the Scenes (2008) that she and her “Big-Bang Theory” co-star and love interest Johnny Galecki had secretly dated for two years earlier in the run of the show, but they were no longer together.
31. Kevin Sussman, who plays Stuart Bloom the comic book store owner, actually worked in a comic book store before becoming an actor.
32. Floors two, three, and four of Sheldon and Leonard’s apartment building are the same set just re-dressed for each scene. This can be seen in the fact that the scuff marks on the moulding are identical on each level as they walk up the stairs.
33. Jim Parsons as Sheldon Cooper wears numerous shirts containing the number 73, this is also the year Jim was born in real life 1973, and Cooper repeatedly states that 73 is his favorite number.
34. With the exception of the pilot, every show name follows the same format as the show’s title, that being the name of a scientific episode or theory.
35. Sara Gilbert (Leslie) who plays a former girlfriend of Leonard’s, also played Johnny Galecki’s girlfriend in Roseanne (1988). Laurie Metcalf, who plays Sheldon’s mother, was also his co-star in Roseanne (1988) and Sara Gilbert’s aunt.
36. Sheldon wasn’t always OCD about knocking on doors. On the fifth episode of season 1, he knocks on Penny’s door without knocking and calling her three times.
37. Kaley Cuoco presented the award Best Performance by an actor in a television series–musical or comedy at the 2011 Golden Globe Awards to co-star Jim Parsons
38. Out of the main male cast-members, Howard is the only one who hasn’t seen Penny naked in person; despite being the first to flirt with her.
39. As the series progressed, each taping of the show was attended by Caltech students.
40. Johnny Galecki was originally approached to play Sheldon, but felt that he would be better fit to play the role of Leonard.