This three sentence summary provides the essential information about the document: The document discusses the American sitcom The Big Bang Theory, which premiered in 2007. It is about the lives of several scientists and their friend, and explores their relationships and careers through a comedy lens. The show became very popular and successful over its eight seasons, and features an ensemble cast led by Jim Parsons, Johnny Galecki, Kaley Cuoco, and others playing the scientist characters and their friends.

1. This article is about the television series. For the scientific theory, see Big Bang. For other uses, see Big
Bang Theory (disambiguation).
"TBBT" redirects here. For the Discovery Channel series, see The Big Brain Theory.
This article may contain an excessive amount of intricate detail that may only interest a specific
audience. Please help relocate any relevant information, and remove excessive detail that may
be against Wikipedia inclusion policy. (January 2015)
The Big Bang Theory
Genre Sitcom[1]
Created by
Chuck Lorre
Bill Prady
Directed by Mark Cendrowski
Starring
 Johnny Galecki
 Jim Parsons
 Kaley Cuoco
 Simon Helberg
 Kunal Nayyar
 Sara Gilbert
 Melissa Rauch
 Mayim Bialik
 Kevin Sussman[2]
Theme music
composer
Barenaked Ladies
Opening theme "Big Bang Theory Theme"[3][4]
Country of origin United States

2. Original language(s) English
No. of seasons 8
No. of episodes 177 (List of episodes)
Production
Executive producer(s)
Chuck Lorre
Bill Prady
Steven Molaro
Producer(s) Faye Oshima Belyeu
Editor(s) Peter Chakos
Camera setup Multi-camera
Running time
18–24 minutes (without
commercials)
Production
company(s)
Chuck Lorre Productions
Warner Bros. Television
Distributor Warner Bros. Television
Broadcast
Original channel CBS
Picture format HDTV 1080i
Audio format DTS-HD Master Audio 5.1
Original run September 24, 2007 – present
External links
Website
The Big Bang Theory 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. It premiered on CBS on September 24, 2007.[5]
The eighth season premiered on
September 22, 2014.

3. The show is primarily centered on five characters living in Pasadena, California: roommates
Leonard Hofstadter and Sheldon Cooper, both physicists at Caltech; Penny, a waitress and
aspiring actress who later becomes a pharmaceutical representative, and who lives across the
hall; and Leonard and Sheldon's equally geeky and socially awkward friends and co-workers,
aerospace engineer Howard Wolowitz and astrophysicist Raj Koothrappali. The geekiness and
intellect of the four guys is contrasted for comic effect with Penny's social skills and common
sense.[6][7]
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); and 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.
Contents
 1 Production
o 1.1 Theme song
o 1.2 Actors' salaries
 2 Main cast
 3 Recurring themes and elements
o 3.1 Science
o 3.2 Science fiction, fantasy, comic books and gaming
o 3.3 Leonard and Penny's relationship
o 3.4 Sheldon and Amy's relationship
o 3.5 Religion
o 3.6 Howard's mother
o 3.7 Vanity card
 4 Reception
o 4.1 Critical reception
o 4.2 U.S. standard ratings
o 4.3 UK distribution and ratings
o 4.4 Canadian ratings
 5 Episodes
 6 Broadcast
 7 DVD/Blu-ray releases
 8 Scientist cameos
 9 Online media
 10 Syndication
 11 Awards and nominations
 12 The Theorists
 13 Notes
 14 References
 15 External links

4. Production
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" who 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);[9][10]
and Iris Bahr as Gilda, a scientist colleague
and friend of the boys who was threatened by Katie's presence. The initial pilot used Thomas
Dolby's hit "She Blinded Me with Science" as theme music.
The series was not picked up, but the creators were given an opportunity to retool the show and
produce a second pilot. They brought in the remaining cast and retooled the show to its final
format. The original unaired pilot has never been officially released, but it has circulated on the
Internet. On the evolution of the show, Chuck Lorre said, "We did the 'Big Bang Pilot' about two
and a half years ago, and it sucked... but there were two remarkable things that worked perfectly,
and that was Johnny and Jim. We rewrote the thing entirely, and then we were blessed with
Kaley and Simon and Kunal." As to whether the world will ever see that original pilot, maybe on
a future DVD release, Lorre said, "Wow, that would be something, we will see. Show your
failures..."[11]
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.[12]
Prior to its airing on CBS, the pilot episode was distributed on iTunes free of
charge. The show premiered September 24, 2007, and was picked up for a full 22-episode season
on October 19, 2007.[13]
The show is filmed in front of a live audience,[14]
and is produced by
Warner Bros. Television and Chuck Lorre Productions.[15]
Production was halted on November
6, 2007, due to the Writers Guild of America strike. Nearly 3 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[16]
and ultimately only 17 episodes were
produced for the first season.[17][18]
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.[19]
With increasing ratings, the show received a two-year renewal through the 2010–11
season in 2009.[20][21]
In 2011, the show was picked up for three more seasons.[22]
In March 2014,
the show was renewed again for three more years through the 2016–17 season. This marks the
second time the series has gained a three-year renewal.[23]
David Saltzberg, a professor of physics and astronomy at the University of California, Los
Angeles, checks scripts and provides dialogue, mathematics equations, and diagrams used as
props.[6]
According to executive producer/co-creator Bill Prady, "We're working on giving
Sheldon an actual problem that he's going to be working on throughout the [first] season so
there's actual progress to the boards ... We worked hard to get all the science right."[7]

5. Several of the actors in The Big Bang Theory previously worked together on Roseanne including
Johnny Galecki, Sara Gilbert, and 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.
Theme song
Single cover for "Big Bang Theory Theme" by Barenaked Ladies (2007)
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,
lead singer and 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. By coincidence,
Robertson had recently read Simon Singh's book Big Bang,[24][25]
and at the concert, he
improvised a freestyle rap about the origins of the universe.[citation needed]
Lorre and Prady phoned
Robertson shortly thereafter and asked him to write the theme song. Having been asked to write
songs for other films and shows only to have them rejected in favor of other artists' songs,
Robertson agreed to write the theme only after learning that Lorre and Prady had not asked
anyone else.
On October 9, 2007, a full-length (1 minute and 45 seconds) version of the song was released
commercially.[26]
Although some sources identify the song title as "History of Everything",[27]
the cover art for the single identifies the title as Big Bang Theory Theme. A music video was also
released via special features on The Complete Fourth Season DVD and Blu-ray set.[28][29]
The
theme was included on the band's greatest hits album, Hits from Yesterday & the Day Before,
which was released on September 27, 2011.[30]
Actors' salaries
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.[31][32]
By
season seven, the three were also receiving 0.25 point of the series' backend money.[33]
Before

6. production began on the eighth season, the five main stars looked to renegotiate new contracts,
with Galecki, Parsons, and Cuoco seeking around $1 million per episode, as well as more
backend money.[33]
Contracts were signed at 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.[34]
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.[35]
In August 2014, Helberg and Nayyar renegotiated 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 8.[36]
Main cast
Main article: List of The Big Bang Theory characters
Main characters in The Big Bang Theory. First row from left: Raj Koothrappali, Leonard Hofstadter,
Penny, Sheldon Cooper, and Howard Wolowitz. Second row from left: Bernadette Rostenkowski-
Wolowitz and Amy Farrah Fowler.
These actors are credited in all episodes of the series:
 Johnny Galecki[37]
as Leonard Hofstadter, PhD – An experimental physicist with an IQ of 173, he
received his PhD when he was 24 years old. His mother, Dr. Beverly Hofstadter (Christine
Baranski), is a neuroscientist and psychiatrist who provided little, if any, nurturing when Leonard
was growing up. Like all of the other major male characters, he is a nerd who loves video games,
comic books and Dungeons & Dragons. Leonard is also lactose intolerant. The straight man of
the series, he shares an apartment in Pasadena with Sheldon. Leonard is smitten with his
neighbor Penny when they first meet. They briefly date at the end of season 1 and the start of
season 2 and in season 3, they begin an on-again, off-again romantic relationship. Leonard also

7. briefly dates Leslie and Dr. Stephanie Barnett (Sara Rue) in season 2, and in season 4, he
becomes seriously involved with Raj's sister Priya (Aarti Mann), a successful lawyer, but she
eventually returns to India and they break up in season 5 when she admits to cheating on him.
In season 5, he and Penny get back together, and at the end of season 7, he proposes and she
accepts.
 Jim Parsons[38]
as Sheldon Cooper, M.A., PhD[39]
– Originally from Galveston, Texas,[40]
he was a
child prodigy with an eidetic memory who began college at the age of 11 (after completing the
fifth grade), started graduate studies at 14, and earned a PhD at 16. A theoretical physicist
researching quantum mechanics and string theory, he has two master's degrees, a PhD and an
Sc.D. However, despite his IQ of 187, he finds many routine aspects of social situations and life
in general difficult to understand and navigate. His father died when he was 14, and his mother,
Mary (Laurie Metcalf) is a devout Christian. He also has a twin sister, Missy (Courtney
Henggeler), who later has a baby in season 7. He has a poor grasp of other people's feelings and
little or no understanding of nuances, often questioning others if a comment is intended as
sarcasm. As a result, he is extremely tactless and acts wildly inappropriately much of the time.
He is determined to have his own way, boasts of his superior intelligence and belittles the
accomplishments of his friends, making him appear petty and childlike. Sheldon has an
extremely ritualized way of living (e.g. sitting in the same spot on the sofa in the apartment or
knocking on a door three times, each time saying the name of the person he's addressing) and a
compulsion to complete things. He is also wary of germs and dislikes physical contact. Despite
all these quirks, in season 4, he begins a relationship with Amy, who eventually becomes his
girlfriend during season 5. In season 8, Sheldon tells Amy that he loves her.
 Kaley Cuoco[41]
as Penny – An aspiring actress from a town outside of Omaha, Nebraska,[42]
Penny lives across the hall from Sheldon and Leonard. She attends casting calls and auditions,
but is not very successful. To pay the bills, she is a waitress and occasional bartender at The
Cheesecake Factory. Penny quits her job in season 7 and at the start of season 8 becomes a
pharmaceutical representative at Bernadette's company after having given up hope of becoming
a successful actress; she appreciates the financial independence the new job gives her. Penny
attended, but did not graduate from a community college (she goes back to school in season 6),
but has far more common sense and social awareness than the other main characters. Penny is
also very untidy and frequently drinks alcohol. To date, her surname has not been revealed. She
dates Leonard at the end of season 1 and the start of season 2, and in season 3, they begin an
on-again, off-again romantic relationship. At the end of season 7, she accepts Leonard's
proposal of marriage (after having proposed to him earlier in the season while intoxicated).
Aside from Leonard, Penny has dated various men over the course of the series, which is at
times brought up by Sheldon. She briefly dated Stuart in season 2, and in seasons 3 and 4 dated
Zack Johnson (Brian Thomas Smith), a handsome and friendly but dim-witted guy, who she
married in Las Vegas (they didn't think weddings in Las Vegas were real). In season 4, Penny,
Bernadette and Amy form their own group, where they hang out in each other's apartments or
go out together. Penny also has a very close friendship with Sheldon, despite his quirks. Cuoco
began being credited as Kaley Cuoco-Sweeting starting with the season 7 episode "The
Convention Conundrum", following her marriage to tennis player Ryan Sweeting.
 Simon Helberg[43]
as Howard Joel Wolowitz,[44]
M.Eng.[45]
– An aerospace engineer, Howard is
Jewish (although not religious) and lived with his mother Debbie (Carol Ann Susi) until her death.
His father left both of them when he was 11 and has not heard from him since, with the
exception of a letter on his eighteenth birthday, which he refused to open. Unlike Sheldon,
Leonard and Raj, Howard lacks a PhD, earning him Sheldon's scorn. He defends this by pointing
out that he has a master's degree in engineering from the elite MIT and that the apparatus he

8. designs are launched into space, unlike the purely abstract work of his friends. He himself goes
into space at the end of season 5, training as an astronaut and serving as a payload specialist on
the International Space Station, although he often annoys his friends by constantly talking about
space. He has a marked sense of humor, which Leonard and Raj occasionally appreciate. In the
early seasons of the show, Howard fancies himself a ladies' man and devises outrageous pick-up
lines (mainly with Penny), which have limited success with women. In season 3 he starts dating
Bernadette, and although they later break up off-screen, they get back together and later get
engaged in season 4 and get married at the end of season 5. In season 6, Howard finally moves
out of his mother's house and into Bernadette's apartment. Howard also has a tendency to
waste money on ridiculous things and often argues with Bernadette over money due to his
oddly low income as an engineer and her high income, resulting in Bernadette often giving
Howard allowances.
 Kunal Nayyar[46]
as Rajesh Ramayan "Raj" Koothrappali, PhD – From New Delhi, India, he works
as a particle astrophysicist at Caltech.[47]
His family is very wealthy (Sheldon describes them as
"Richie Rich rich"). Over the course of the series he communicates with his parents, Dr. and Mrs.
V.M. Koothrappali (Brian George and Alice Amter), via webcam (they later divorce in season 8).
He is very shy around women and is unable to talk to them for the first six seasons (except for
his mother and his sister), unless he drinks alcohol (or at least thinks he has drunk it) or takes an
experimental medication. Unfortunately, the former gives him an outrageous, unpredictable
personality, while the latter causes unforeseen side effects. Even so, he often has better luck
with women than his overly confident best friend, Howard. Raj also has very feminine tastes and
often takes on a stereotypical female role in his close friendship with Howard, but he insists that
he is not gay.[48]
In season 4, his sister Priya stays with him and becomes Leonard's girlfriend
(much to Raj's annoyance). In season 6, Raj meets Lucy (Kate Micucci), who also has social
anxiety, and they begin a relationship. However, Lucy ends the relationship, as she feels too
pressured when he wants her to meet his friends. Afterwards, a heartbroken Raj finally speaks
to Penny without having consumed alcohol and overcomes his selective mutism. In season 7, he
begins dating Emily Sweeney (Laura Spencer), a dermatologist, and their relationship later
becomes exclusive. Raj also has a Yorkshire Terrier called Cinnamon, and the gang often joke
about how unusually close he is with his dog.
These actors were first credited as guest stars and later promoted to main cast:
 Sara Gilbert as Leslie Winkle, PhD (recurring season 1, starring season 2, guest star season
3)[49][50]
– a physicist who works in the same lab as Leonard. In appearance, she is essentially
Leonard's female counterpart, wearing black-framed glasses and sweat jackets. She is an enemy
of Sheldon's, due to their conflicting scientific theories. Though each considers the other to be
intellectually inferior, Leslie is much wittier than Sheldon, regularly calls him "dumbass", and
usually bests him in their repartee. Leslie has casual sex with Leonard and later Howard. Gilbert
and Galecki played the on-screen couple of Darlene Connor and David Healy in Roseanne.
Gilbert was promoted to a main cast member during the second season, but was demoted back
to guest star status because producers could not come up with enough material for the
character.[49]
Gilbert left the series after season 3 to focus her efforts on The Talk, on which she
serves as executive producer for CBS.
 Melissa Rauch as Bernadette Rostenkowski-Wolowitz, PhD (recurring season 3, starring since
season 4)[51]
– a young woman with a very high-pitched voice who is initially a waitress co-
worker of Penny's, paying her way through graduate school, studying microbiology. Bernadette
is of Polish origin and was raised in a Catholic household. Her father Mike (Casey Sander) is a

9. toughened retired police officer and she has four other siblings. Bernadette is introduced to
Howard by Penny as a result of an agreement between Howard and Leonard that if either ever
ended up with a hot girlfriend, he would get the girlfriend to introduce the other to "a hot
chick". At first, they do not get along, apparently having nothing in common, until they find out
that they both have overbearing mothers. During season 3, they date and then break up off-
screen. They get back together and get engaged in season 4 and marry at the end of season 5.
After successfully defending her doctoral thesis, she lands a high-paying research position at the
end of season 4 (her high income becomes a source of conflict between her and Howard in later
seasons). Although generally a sweet and good natured person, Bernadette has a very short
temper and can be vindictive and lash out when provoked, often sounding like Howard's
mother, and intimidating her colleagues. She is also shown to have a competitive streak.
 Mayim Bialik, PhD, as Amy Farrah Fowler, PhD (guest star season 3, starring since mid-season
4)[52]
– a woman selected by an online dating site as Sheldon's perfect mate after Raj and
Howard secretly set up an account using Sheldon's information, prompting Raj to comment,
"We finally have proof that aliens walk among us!"[53]
Amy is from Glendale and is a fan of Little
House on the Prairie. She and Sheldon initially have many similar traits, though after befriending
Penny and Bernadette, Amy eventually becomes more interested in social and romantic
interaction and is more socially aware than Sheldon. Once she and Sheldon meet, she becomes,
as Sheldon puts it, a girl who is his friend, but not his "girlfriend". Their relationship slowly
progresses up to the point where Sheldon considers her his girlfriend and tells her that he loves
her. Amy's sexual frustration in her relationship with Sheldon is a recurring topic in the series.
Amy also believes she and Penny are best friends ("besties", as she puts it), a sentiment that
Penny does not share. Penny eventually becomes a real friend, overlooking Amy's Sheldon-like
qualities. Amy's admiration for Penny has at times bordered on physical attraction. Amy has a
PhD in neurobiology, and frequently uses monkeys in her research and experiments. Bialik
herself has a doctorate in neuroscience. In the season 1 episode "The Bat Jar Conjecture", Raj
suggests recruiting "the girl who plays TV's Blossom" (whom Bialik played) for their Physics Bowl
team.
 Kevin Sussman as Stuart Bloom (recurring seasons 2–5, & 7, starring season 6 & 8) – the mild-
mannered, under-confident individual who runs the comic book store that the guys frequent. A
brilliant artist, Stuart is a graduate of the prestigious Rhode Island School of Design and though
he is socially awkward, he possesses slightly better social skills than the rest of the guys. Unlike
the others he is not a techno-geek. During Stuart's first appearance, the guys bring Penny along
to the store, and he manages to ask her on a date. They go out a few times, until Penny
mistakenly calls him "Leonard" while they are making out, leaving him devastated. In season 4,
he implies he is in financial trouble and that the comic book store is now also his home. At
Howard's bachelor party, Stuart uses his toast to tell Howard how lucky he is and compares it to
his own situation of living in the back of his store. In season 6, he is invited to join the guys'
group while Howard is in space. At the end of season 7, the comic book store burns down and
he gets a new job caring for Howard's mother. The two become close and develop a strange
relationship, much to the annoyance of Howard. He also briefly dates Howard's second cousin
Jeanie (Kara Luiz), to whom Howard lost his virginity.
Summary of character appearances
Character Portrayed by Appearance Seasons

10. count 1 2 3 4 5 6 7 8
Leonard
Hofstadter
Johnny Galecki 170 (All) Main
Sheldon
Cooper
Jim Parsons 170 (All) Main
Penny Kaley Cuoco 168 Main
Howard
Wolowitz
Simon Helberg 170 (All) Main
Raj
Koothrappali
Kunal Nayyar 170 (All) Main
Leslie Winkle Sara Gilbert 8 Recurring Main Guest N/A
Bernadette
Rostenkowski-
Wolowitz
Melissa Rauch 107 N/A Recurring Main
Amy Farrah
Fowler
Mayim Bialik 101 N/A Guest Main
Stuart Bloom Kevin Sussman 36 N/A Recurring Main Recurring Main
Recurring themes and elements
This section needs additional citations for verification. Please help improve this article by
adding citations to reliable sources. Unsourced material may be challenged and removed.
(February 2015)
Science
Much of the show focuses on science, particularly physics. The four main male characters are
employed at Caltech and have science-related occupations, as do Bernadette and Amy. The
characters frequently banter about scientific theories or news (notably around the start of the
show), and make science-related jokes.
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.[54]

11. When Leonard joins Sheldon, Raj, and Howard on a three-month Arctic research trip, it
separates Leonard and Penny at a time 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.[55]
Sheldon and Amy also
briefly end their relationship after an argument over which of their fields is superior.[56]
David Saltzberg, who has a PhD in physics, has served as the science consultant for the show for
six seasons and attends every taping.[57]
While Saltzberg knows physics, he sometimes needs
assistance from Mayim Bialik, who has a PhD in neuroscience.[58]
Saltzberg sees early versions
of scripts which need scientific information added to them, and he also points out where the
writers, despite their knowledge of science, have made a mistake. He is usually not needed
during a taping unless a lot of science, and especially the whiteboard, is involved.[58]
Science fiction, fantasy, comic books and gaming
The four main male characters are all avid science fiction, fantasy, and comic book fans and
memorabilia collectors.
Star Trek in particular is frequently referenced and Sheldon identifies strongly with the character
of Spock, so much so that when he is given a used napkin signed by Leonard Nimoy as a
Christmas gift from Penny he is overwhelmed with excitement and gratitude ("I possess the
DNA of Leonard Nimoy?!").[59]
Star Trek: The Original Series cast member George Takei has
made a cameo, and Leonard Nimoy made a cameo as the voice of Sheldon's vintage Mr. Spock
action figure (both cameos were in dream sequences). Star Trek: The Next Generation cast
members Brent Spiner and LeVar Burton have had cameos as themselves,[60][61]
while Wil
Wheaton has a recurring role as a fictionalized version of himself.
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.[62][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.
Wednesday night is the group's designated "comic book night"[63]
because that is the day of the
week when new comic books are released. The comic book store is run by fellow geek and
recurring character Stuart. On a number of occasions, the group members have dressed up as pop
culture characters, including The Flash, Aquaman, Frodo Baggins, Superman, Batman, Spock,
The Doctor, Green Lantern, and Thor.[64]
As a consequence of losing a bet to Stuart and Wil
Wheaton, the group members are forced to visit the comic book store dressed as Catwoman,
Wonder Woman, Batgirl, and Supergirl.[65]
DC Comics announced that, to promote its comics,
the company will sponsor Sheldon wearing Green Lantern T-shirts.[66]

12. Various games have been featured, as well as referenced, on the show (e.g. World of Warcraft,
Halo, Mario, etc.), including fictional games like Mystic Warlords of Ka'a (which became a
reality in 2011)[67]
and Rock-paper-scissors-lizard-Spock.
Leonard and Penny's relationship
One of the recurring plot lines is the relationship between Leonard and Penny. Leonard becomes
attracted to Penny in the pilot episode and his need to do favors for her is a frequent point of
humor in the first season. Their first long term relationship begins when Leonard returns from a
three-month expedition to the North Pole in the season 3 premiere. However, when Leonard tells
Penny that he loves her, she realizes she cannot say it back. Both Leonard and Penny go on to
date other people; most notably with Leonard dating Raj's sister Priya for much of season 4. This
relationship is jeopardized when Leonard comes to falsely believe that Raj has slept with Penny,
and ultimately ends when Priya sleeps with a former boyfriend in "The Good Guy Fluctuation".
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.
Sheldon and Amy's relationship
In the third season finale, Raj and Howard search for a woman compatible with Sheldon and
discover neurobiologist Amy Farrah Fowler. Like him, she has a history of social ineptitude and
only participates in online dating to fulfill an agreement with her mother. This spawns a storyline
in which Sheldon and Amy communicate daily via text messages, email, and Twitter while
insisting to Leonard and Penny that they are not romantically involved. In "The Agreement
Dissection", Sheldon and Amy talk in her apartment after a night of dancing and she kisses him
on the lips. Instead of getting annoyed, Sheldon says "fascinating" and later asks Amy to be his
girlfriend in "The Flaming Spittoon Acquisition". The same night and episode, he draws up "The
Relationship Agreement" to verify the ground rules of him as her boyfriend and vice versa
(similar to his "Roommate Agreement" with Leonard). Amy agrees but later regrets not having a
lawyer read through it.
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 premiere 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

13. 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" after
being questioned by Penny, 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" when she laments that
their friends think their relationship is a joke. Sheldon replies that they are not a joke, explaining
that he never thought about intimacy with anyone before Amy.[68]
"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 having a more intimate
relationship with Amy. However, in the season finale, Sheldon leaves town temporarily to cope
with several changes and Amy becomes distraught. In "The Prom Equivalency", when Amy and
Bernadette host a recreation of prom night, Sheldon becomes uncomfortable and hides in his
room to avoid going. In the resulting stand-off, Amy is about to confess that she loves Sheldon,
but he quickly surprises her by saying that he loves her too, prompting Amy to have a panic
attack.
Religion
A recurrent theme is Sheldon's conflict with his devout mother, Mary, possessing creationist
beliefs referred to by Sheldon as "pre-Enlightenment mythology".[69]
Evidence of Sheldon's
irreligion is seen when he is heard exclaiming "Why hast thou forsaken me, o deity whose
existence I doubt?" upon the discovery that his World of Warcraft account has been hacked.[70]
According to Raj, Sheldon also begged the deity in which he did not believe to kill him quickly
upon getting food poisoning at the Rose Bowl.[n 1]
On the other hand Sheldon says he wishes "to
employ his rare and precious mental faculties to tear the mask off nature and stare at the face of
God."[71]
Sheldon's religious upbringing leads to moments of religious interjection when his
emotions are high – on one occasion, he happily exclaims "Thank you, Jesus!" when he scores a
strike in bowling, quickly adding "As my mother would say."[72]
In addition, he frequently says
the word "Lord" when he is upset.
At the same time, a running gag in the series is the fact that Howard, who is Jewish and Raj, who
is Hindu, frequently defy many of their respective religious customs without worry, such as their
constant flouting of dietary prohibitions. They both also tend to give each other grief about them.
In the episode "The Financial Permeability", Raj quotes from the book of Leviticus after Howard
eats pork, and Howard counters with the fact that he keeps quiet when Raj eats a Whopper.[73]
Nevertheless, they are seen to be semi-observant. Raj, for example, occasionally mentions
reincarnation and explains his belief in karma, opining that it is "practically Newtonian – for
every action there is an equal and opposite reaction." Howard wears fake tattoo sleeves during a
failed plan for him and Raj to pick up Goth women so he can complete his quest "and still get
buried in a Jewish cemetery"; at another point, Sheldon criticizes him by saying Howard does
not join his friends for video game competitions during the Jewish High Holidays.
Another theme is Penny's confidence in supernatural concepts such as ghosts, astrology,
psychics, and voodoo that frequently conflict with Leonard and Sheldon's scientific knowledge

14. and skepticism. This is first seen in the Pilot, when she makes reference to her being a Sagittarius
but is most frequently seen in an episode in which she and Leonard have a falling out over the
validity of psychics.[74]
Howard's mother
In scenes set at Howard's home in which he interacts with his never-seen mother (voiced by
Carol Ann Susi until her death), he always does so via shouting conversations between the rooms
in his house, and she similarly interacts with other characters in this manner.[75]
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.[76]
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,[77]
and Sheldon to refer to their relationship as Oedipal. [78]
In Season 8, Howard's
mother dies from a heart attack, which devastates Howard and Stuart, who briefly lived with
Mrs. Wolowitz.
Vanity card
Like most shows created by Chuck Lorre, The Big Bang Theory ends by showing a vanity card
written by Lorre after the credits, followed by the Warner Bros. Television closing logo. These
cards are archived on Lorre's website.[79]
Reception
Critical reception
The Big Bang Theory initially received mixed reviews[80]
and originally received a score of
57/100 from review aggregator Metacritic, indicating "mixed or average reviews". Tom Shales
of The Washington Post gave the show a positive review, saying "Big Bang is the funniest new
sitcom of the season".[81]
Robert Bianco of USA Today also gave the show a positive review,
saying "This may not be the sitcom breakthrough for which we've all been hoping, but Lorre has
produced a first episode that leaves you eager to try the second".[82]
Robert Lloyd of the Los
Angeles Times gave a mixed review, stating "It's just the same joke endlessly repeated – the
everyday translated into geek-speak, and the obscure and difficult treated as if it were common
knowledge".[83]
Mike Duffy of the Detroit Free Press gave a negative review, stating "This is by
far the least charming—the lame, leering sitcom tales of two brainiac losers goofily smitten by
the babelicious girl next door. It's about as witty as a pocket protector".[84][85]
James Chamberlin of IGN gave season 2 an 8.4 out of 10 score, saying, "This may be a show
about nerds, but you don't have to be a brainiac to enjoy it."[86]
Amanda Sloane Murray, writing
for the same website, gave season three nine out of 10, describing it as "more intelligent than

15. most sitcoms in recent memory".[87]
The American Film Institute ranked season three one of the
10 best television seasons of 2009.[88]
Leigh H. Edwards of PopMatters gave season 4 an 8/10, commenting "The comic commentary
may be poking gentle fun at nerds, but the real target of the show's sharp satire is the arbitrary,
self-serving stupidity of mainstream culture".[89]
On the other hand Brian Tallerico of Hollywood
Chicago panned the series writing: "There's nothing here that seems even remotely original."[90]
Tom Gliatto of People remarked of season 5, "It's bright and obvious as a cartoon yet written
with a clean, precise patter of jokes. It's also very well cast".[91]
Kate Ward of Entertainment Weekly gave season 6 a 91/100, remarking "Bialik manages to steal
scenes from Parsons as if she's been with the crew since, well, the big bang".[92]
Robert Bianco
continued to give a positive review, noting "When it comes to making viewers catch their breath
from laughing, no show tops Big Bang, and that's an ability that should never be undervalued in
a comedy. Bang is one of those rare series where just thinking about some of the plots is enough
to make you laugh all over again".[93]
On the other hand, June Thomas of Slant Magazine gave
the season a negative review, calling it "disappointing".[94]
U.S. standard ratings
The Big Bang Theory has been highly rated since its premiere. When the third season premiered
on September 21, 2009, The Big Bang Theory ranked as CBS's highest-rated show of that
evening in the adults 18–49 demographic (4.6/10) along with a then-series-high 12.83 million
viewers.[95]
After the first three seasons aired at different times on Monday nights, CBS moved
the show to Thursdays at 8:00 ET for the 2010–2011 schedule, to be in direct competition with
NBC's Comedy Block and Fox's American Idol (then the longest reigning leading primetime
show on U.S. television from 2004 to 2011).[96]
During its fourth season, it became television's
highest rated comedy, just barely beating out eight-year champ Two and a Half Men. However,
in the age 18–49 demographic (the show's target age range), it was the second highest rated
comedy, behind ABC's Modern Family. The fifth season opened with viewing figures of over 14
million.[97]
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,[98]
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,[99][100]
and was third in total viewers, trailing NCIS and Sunday
Night Football.[101]
Season seven of the show 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.[102][103]
Showrunner Steve Molaro, who took over from Bill Prady with the sixth season, credits some of
the show's success to the sitcom's exposure in off-network syndication, particularly on TBS,
while Michael Schneider of TV Guide attributes it to the timeslot move two seasons earlier.

16. Chuck Lorre and CBS Entertainment president Nina Tassler also credit the success to the
influence of Molaro, in particular the deepening exploration of the firmly established regular
characters and their interpersonal relationships, such as the on-again, off-again relationship
between Leonard and Penny.[104]
Throughout much of the 2012–13 season, The Big Bang Theory
placed first in all of syndication ratings, receiving formidable competition from only Judge Judy
and Wheel of Fortune (first-run syndication programs). By the end of the 2012–13 television
season, The Big Bang Theory had dethroned Judge Judy as the ratings leader in all of syndicated
programming with 7.1, Judy descending to second place for that season with a 7.0.[105]
The Big
Bang Theory did not place first in syndication ratings for the 2013-14 television season, beaten
out by Judge Judy.[106]
Season Timeslot (ET)
Season
premiere
Season
finale
TV
season
No. of
episodes
Rank
Avg.
viewers
(in
millions)
Most watched
episode
Viewers
(millions)
1
Monday 8:30
p.m.
(September
24 – November
12, 2007)
Monday 8:00
p.m. (March
17 – May 19,
2008)
September
24, 2007
May
19,
2008
2007–
08
17 68 8.31[107]
"The Dumpling
Paradox"
9.68[108]
2
Monday 8:00
p.m.
(September 22,
2008 – May 11,
2009)
Monday 9:30
p.m. (February
9, 2009)
September
22, 2008
May
11,
2009
2008–
09
23 44 10.00[109]
"The Maternal
Capacitance"
13.11[110]
3
Monday 9:30
p.m.
(September 21,
2009 – May 24,
2010)
Monday 9:00
p.m. (May 3,
2010)
September
21, 2009
May
24,
2010
2009–
10
23 12 14.14[111]
"The Precious
Fragmentation"
16.32[112]
4 Thursday 8:00 September May 2010– 24 15 13.14[113]
"The Robotic 14.04[114]

17. p.m. 23, 2010 19,
2011
11 Manipulation"
5
September
22, 2011
May
10,
2012
2011–
12
24 8 15.82[115]
"The Friendship
Contraction"
16.54[116]
6
September
27, 2012
May
16,
2013
2012–
13
24 3 18.68[101]
"The Bakersfield
Expedition"
20.00[98]
7
September
26, 2013
May
15,
2014
2013–
14
24 2 19.96[117]
"The Deception
Verification"
20.44[102]
8
Monday 8:00
p.m. (Sept. 22,
2014 – October
20, 2014)
Thursday 8:00
p.m. (October
30, 2014 –)
September
22, 2014
TBA
2014–
15
24 TBD TBD TBD TBD
UK distribution and ratings
The show made its UK debut on Channel 4 on February 14, 2008. The show was also shown as a
'first-look' on Channel 4's digital offshoot E4 prior to the main channel's airing. While the show's
ratings were not deemed strong enough for the main channel, they were considered the opposite
for E4. For each following season, all episodes were shown first-run on E4, with episodes only
aired on the main channel in a repeat capacity, usually on a weekend morning. From the third
season, the show aired in two parts, being split so that it could air new episodes for longer
throughout the year. This was due to rising ratings. The first part began airing on 17 December
2009 at 9:00 p.m. while the second part, containing the remaining eleven episodes, began airing
in the same time period from May 6, 2010. The first half of the fourth season began airing on 4
November 2010, at 9:00 p.m., drawing 877,000 viewers, with a further 256,000 watching on the
E4+1 hour service. This gave the show an overall total of 1.13 million viewers, making it E4's
most watched programme for that week. The increased ratings continued over subsequent
weeks.[118]
The fourth season's second half began on June 30, 2011. Season 5 began airing on 3
November 2011 at 8:00 p.m. as part of E4's Comedy Thursdays, acting as a lead-in to the
channel's newest comedy, Perfect Couples. Episode 19, the highest-viewed episode of the
season, attracted 1.4 million viewers.[119]
Season 6 premiered on 15 November 2012, with 1.89
million viewers and a further 469,000 on the time shift channel, bringing the total to 2.31
million, E4's highest viewing ratings of 2012, and the highest the channel had received since
June 2011. The sixth season returned in mid 2013 to finish airing the remaining

18. episodes.[120]
Season 7 premiered on E4 on October 31, 2013 at 8:30pm and hit multiple ratings
records this season. The second half of season seven aired in mid 2014.[121]
The eighth season
premiered on E4 on October 23, 2014 at 8:30 p.m.[122]
During its eighth season, The Big Bang
Theory shared its 8:30 p.m. time period with fellow CBS comedy, 2 Broke Girls. Following the
airing of the first eight episodes of that show's fourth season, The Big Bang Theory will return to
finish airing its eighth season on 19 March 2015.[123]
Canadian ratings
The Big Bang Theory started off quietly in Canada, but managed to garner major success in later
seasons. The Big Bang Theory is telecast throughout Canada via the CTV Television Network in
simultaneous substitution with cross-border CBS affiliates. Now immensely pop