

The Big Bang Theory
Smart is the new sexy.
Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.
Cast

Johnny Galecki
Leonard Hofstadter

Jim Parsons
Sheldon Cooper

Kaley Cuoco
Penny

Simon Helberg
Howard Wolowitz

Kunal Nayyar
Rajesh Koothrappali

Melissa Rauch
Bernadette Rostenkowski

Mayim Bialik
Amy Farrah Fowler
Seasons
University physicists Leonard and Sheldon know whether to use an integral or a differential to solve the area under a curve. But they don't have a clue about girls. Or dating. Or clothes. Or parties. Or having fun. Or, basically, life. So when a pretty blonde named Penny moves in the apartment across the hall, the guys decide to get an education outside of the classroom. Boys, you have a lot to learn.

E1Pilot
Sep 24, 2007
Brilliant physicist roommates Leonard and Sheldon meet their new neighbor Penny, who begins showing them that as much as they know about science, they know little about actual living.

E2The Big Bran Hypothesis
Oct 1, 2007
Leonard volunteers to sign for a package in an attempt to make a good impression on Penny, but when he enlists Sheldon for help, his attempt at chivalry goes terribly awry.

E3The Fuzzy Boots Corollary
Oct 8, 2007
Leonard asks a woman out after he finds out that Penny is seeing someone.

E4The Luminous Fish Effect
Oct 15, 2007
Sheldon's getting fired forces him to explore what life has to offer outside physics, leaving Leonard to take drastic action to snap his friend out of his funk.

E5The Hamburger Postulate
Oct 22, 2007
Fearing he's wasting his time on Penny, Leonard ends up making a connection with Leslie.

E6The Middle-Earth Paradigm
Oct 29, 2007
Penny hosts a Halloween party, putting Leonard, Sheldon, Wolowitz, and Koothrappali through a new test of their social skills.

E7The Dumpling Paradox
Nov 5, 2007
With Wolowitz AWOL with one of her friends, Penny's recruited to fill in for him on the guys' Halo team

E8The Grasshopper Experiment
Nov 12, 2007
Raj's parents set him up on a blind date, but just when he discovers he can talk to her, she shows interest in Sheldon.

E9The Cooper-Hofstadter Polarization
Mar 17, 2008
When they're invited to present at a physics conference, Sheldon's reluctance to share the credit leads to a tiff between him and Leonard, and Penny's intervention only exacerbates the situation.

E10The Loobenfeld Decay
Mar 24, 2008
Leonard and Sheldon each lie to avoid seeing Penny's concert, but Sheldon's is a bit too complicated for his own good.

E11The Pancake Batter Anomaly
Mar 31, 2008
With his friends knowing how sour he acts when sick—and avoiding him as a result—Sheldon is nursed by Penny, who hasn't a clue what she's in for.

E12The Jerusalem Duality
Apr 14, 2008
With Sheldon rattled over meeting Dennis, a 15-year-old physicist who's smarter than he, Leonard helps him look for a way to debunk Dennis's research.

E13The Bat Jar Conjecture
Apr 21, 2008
Sheldon finds himself booted from the gang's Physics Bowl team and replaced with Leslie, so he forms his own team, hoping to prove he's superior.

E14The Nerdvana Annihilation
Apr 28, 2008
When delivery of another collectible leads to Penny's lashing out at Leonard, he decides it's time to give up his habit, much to his friends' protestation.

E15The Pork Chop Indeterminacy
May 5, 2008
The rest of the gang fall for Sheldon's twin sister, and Leonard's plan to win her heart is derailed when Sheldon declares he'll be the one to decide who can date her.

E16The Peanut Reaction
May 12, 2008
Penny wants to throw a surprise party for Leonard, but Sheldon's indulgence at an electronics store throws her off-track.

E17The Tangerine Factor
May 19, 2008
Penny's break-up spurs Leonard to summon the courage to ask her out, and each goes to Sheldon for advice on their upcoming date.
This season, Leonard gets a girl. So does Sheldon. Howard drives the Mars Rover into a ditch. Raj woos a terminator. Gorgeous girl-next-door Penny falls under the spell of Age of Conan. And super-smart, ueberconfident Leslie Winkler reduces mere men to spineless jellyfish.

E1The Bad Fish Paradigm
Sep 22, 2008
Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.

E2The Codpiece Topology
Sep 29, 2008
A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.

E3The Barbarian Sublimation
Oct 6, 2008
Sheldon creates a monster when he introduces Penny to online gaming.

E4The Griffin Equivalency
Oct 13, 2008
Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.

E5The Euclid Alternative
Oct 20, 2008
Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.

E6The Cooper-Nowitzki Theorem
Nov 3, 2008
Sheldon and the gang are confused when a young grad student is attracted to him.

E7The Panty Piñata Polarization
Nov 10, 2008
When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.

E8The Lizard-Spock Expansion
Nov 17, 2008
Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.

E9The White Asparagus Triangulation
Nov 24, 2008
Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.

E10The Vartabedian Conundrum
Dec 8, 2008
Leonard asks Penny for advice when his new relationship starts moving too fast.

E11The Bath Item Gift Hypothesis
Dec 15, 2008
Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's obsession with gift-giving etiquette.

E12The Killer Robot Instability
Jan 12, 2009
Penny's criticism of Wolowitz's romantic life pushes him into depression and AWOL for a fighting robot battle the rest of guys are depending on him for.

E13The Friendship Algorithm
Jan 19, 2009
Sheldon creates a scientific procedure for making friends.

E14The Financial Permeability
Feb 2, 2009
Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penny's ex-boyfriend.

E15The Maternal Capacitance
Feb 9, 2009
Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.

E16The Cushion Saturation
Mar 2, 2009
A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.

E17The Terminator Decoupling
Mar 9, 2009
Leonard, Sheldon and Wolowitz are ecstatic to learn that a famous science-fiction actress (Summer Glau) is on board the train they are taking to San Francisco.

E18The Work Song Nanocluster
Mar 16, 2009
Penny's home business turns into a complete nightmare when Sheldon takes over.

E19The Dead Hooker Juxtaposition
Mar 30, 2009
Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."

E20The Hofstadter Isotope
Apr 13, 2009
A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladies' Night.

E21The Vegas Renormalization
Apr 27, 2009
Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out of his apartment and must stay with Penny.

E22The Classified Materials Turbulence
May 4, 2009
Penny's second date with Stuart sees her making a comment that gives Leonard new hope for a relationship with her. Wolowitz realizes there's a crucial error in a NASA project he's working on.

E23The Monopolar Expedition
May 11, 2009
The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leonard.
Worlds collide in Season 3! A love affair with Penny has opened a big, wide, wonderful world of romance for Leonard. But Sheldon likes the world just the way it was, thank you. All of which makes for a zany comic triangle with brainy, clueless Sheldon and practical, grounded Penny hilariously vying for the role of hypotenuse.

E1The Electric Can Opener Fluctuation
Sep 21, 2009
When Sheldon learns the guys tampered with his expedition data he got from the arctic, he leaves to Texas in disgrace. This results in the guys following him, which threatens Leonard's hope for some romantic time with Penny and the guys' friendship with Sheldon.

E2The Jiminy Conjecture
Sep 28, 2009
Leonard and Penny struggle to recover from an awkward first hookup while Sheldon and Howard stake their best comic books on a bet to determine the species of a cricket.

E3The Gothowitz Deviation
Oct 5, 2009
Howard and Raj visit a Goth nightclub to pick up women while Sheldon attempts to build a better Penny using chocolate-based behavior modification.

E4The Pirate Solution
Oct 12, 2009
Raj must find a new job or be sent back to India, but Sheldon has a solution, which leaves Leonard and Penny dealing with Howard as a third wheel.

E5The Creepy Candy Coating Corollary
Oct 19, 2009
After overhearing that Wil Wheaton is entering a trading-card competition, Sheldon decides to enter it himself. Meanwhile, Penny sets up one of her friends on a date with Wolowitz.

E6The Cornhusker Vortex
Nov 2, 2009
Sheldon becomes Leonard's teacher in order to understand football, while an incident with flying a kite threatens Howard and Raj's friendship.

E7The Guitarist Amplification
Nov 9, 2009
A squabble between Leonard and Penny sees Sheldon playing mediator, though out of his own incovenience from the sitiation rather than altruism.

E8The Adhesive Duck Deficiency
Nov 16, 2009
With Leonard, Howard and Raj away camping in the desert, an injured Penny has only Sheldon to rely on.

E9The Vengeance Formulation
Nov 23, 2009
After he's humiliated on National Public Radio, Sheldon vows to destroy Kripke, while Wolowitz tries not to destroy his new relationship with Bernadette.

E10The Gorilla Experiment
Dec 7, 2009
Penny gets help from Sheldon in order to understand what Leonard's work is, while Wolowitz develops a jealousy when Leonard starts hanging out with his new girlfriend.

E11The Maternal Congruence
Dec 14, 2009
A Christmas visit from his mother has Leonard discovering she's kept a lot of news from him that she shares with Sheldon and worrying if she'll approve of his romance with Penny.

E12The Psychic Vortex
Jan 11, 2010
Leonard is aghast to find out a secret of Penny's: she believes in psychics. Meanwhile, Sheldon tries to assist Koothrappali in picking up a girl at a university mixer.

E13The Bozeman Reaction
Jan 18, 2010
When their apartment is robbed, Leonard and Sheldon turn to their friends to create a state-of-the-art security system.

E14The Einstein Approximation
Feb 1, 2010
Sheldon's search for the answer to a physics problem leads him to work at the Cheesecake Factory with Penny.

E15The Large Hadron Collision
Feb 8, 2010
Leonard can only bring one guest on a trip to see CERN's Large Hadron Collider (the world's largest and highest energy particle accelerator) in Switzerland on Valentine's Day.

E16The Excelsior Acquisition
Mar 1, 2010
Sheldon winds up in traffic court when he gets a ticket because of Penny.

E17The Precious Fragmentation
Mar 8, 2010
When the guys find a ring from "The Lord of the Rings" at a garage sale, it threatens to tear them apart.

E18The Pants Alternative
Mar 22, 2010
Sheldon's friends come to his aid when his fear of public speaking stands between him and a coveted award.

E19The Wheaton Recurrence
Apr 12, 2010
A fight between Leonard and Penny threatens their relationship, while Sheldon battles Wil Wheaton in bowling.

E20The Spaghetti Catalyst
May 3, 2010
When Leonard and Penny aren't speaking, Sheldon goes to extremes to keep them both happy.

E21The Plimpton Stimulation
May 10, 2010
Leonard and Sheldon compete for the attention of a famous female physicist.

E22The Staircase Implementation
May 17, 2010
Leonard tells Penny about how he met Sheldon for the first time...and what happened to the elevator.

E23The Lunar Excitation
May 24, 2010
While Penny worries that dating Leonard has ruined her for normal guys, Wolowitz and Koothrappali search for Sheldon's perfect match online.
This season the Big Bang gang’s romantic universe expands. On the rebound from Penny, Leonard falls into the arms of Raj’s sister Priya. Sheldon gets a girlfriend, or rather a friend who is a girl: Amy, a dour neurobiologist who declares herself besties with Penny. Howard and Bernadette heat up. And so do Raj and Bernadette (at least in Raj’s Bollywood daydream).

E1The Robotic Manipulation
Sep 23, 2010
Penny tags along on Sheldon's first ever date; Wolowitz finds a new use for a robotic arm.

E2The Cruciferous Vegetable Amplification
Sep 30, 2010
Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.

E3The Zazzy Substitution
Oct 7, 2010
The guys are concerned as Sheldon searches for an alternative to human companionship.

E4The Hot Troll Deviation
Oct 14, 2010
An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.

E5The Desperation Emanation
Oct 21, 2010
Leonard realizes he’s the only one without a girlfriend, while Sheldon wants to get rid of his.

E6The Irish Pub Formulation
Oct 28, 2010
Leonard keeps an affair a secret from Sheldon, Howard and Raj.

E7The Apology Insufficiency
Nov 4, 2010
Sheldon's answers during an FBI interview put Wolowitz's security clearance in jeopardy.

E8The 21-Second Excitation
Nov 11, 2010
While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.

E9The Boyfriend Complexity
Nov 18, 2010
Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.

E10The Alien Parasite Hypothesis
Dec 9, 2010
Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.

E11The Justice League Recombination
Dec 16, 2010
The guys find a "super" use for Penny's new boyfriend, Zack, when they enter a costume contest as the Justice League.

E12The Bus Pants Utilization
Jan 6, 2011
Leonard's idea for a smartphone app derails his friendship with Sheldon.

E13The Love Car Displacement
Jan 20, 2011
Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.

E14The Thespian Catalyst
Feb 3, 2011
Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.

E15The Benefactor Factor
Feb 10, 2011
A wealthy donor to the university makes Leonard consider how far he's willing to go for the sake of science.

E16The Cohabitation Formulation
Feb 17, 2011
As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj's sister.

E17The Toast Derivation
Feb 24, 2011
Sheldon becomes concerned when everybody begins to hang out at Raj's apartment and discovers Leonard is the center of the group.

E18The Prestidigitation Approximation
Mar 10, 2011
Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.

E19The Zarnecki Incursion
Mar 31, 2011
Sheldon's online-game account is hacked by Todd Zarnecki, who then proceeds to steal all his items prompting the guys to go on a quest to retrieve them. Penny, Bernadette and Amy discuss how Penny groomed Leonard to be willing to try various things and more adventurous boyfriend... for some other woman — Priya.

E20The Herb Garden Germination
Apr 7, 2011
Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to even higher level.

E21The Agreement Dissection
Apr 28, 2011
When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violations of the roommate agreement. However, before he can get too far, Priya uses her skills as a lawyer to nullify the charges due to the agreement's vague wording, much to Sheldon's dismay. When the guys take advantage of Priya's skills in order to eat Greek food on pizza night, Sheldon goes to Penny, who invites him to a girls' night out with Amy and Bernadette, which Sheldon agrees to after Penny mentions that they may be talking trash about Priya. After the girls drink some cocktails, they decide to take Sheldon dancing, which Sheldon reluctantly goes along with. After dancing, Sheldon takes an intoxicated Amy back to her apartment and as well as talking about Priya, meets a monkey who is addicted to smoking cigarettes. Amy tells Sheldon not to give in to Priya's law skills, before kissing him and going to her bathroom to vomit.

E22The Wildebeest Implementation
May 5, 2011
Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.

E23The Engagement Reaction
May 12, 2011
When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.

E24The Roommate Transmogrification
May 19, 2011
When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she's regrets.
In season five, Penny and Leonard's relationship is relaunched in full "beta test" mode, while Sheldon, Howard, and Raj discover the feminine mystique is something that cannot be easily graphed or calculated. As Sheldon makes begrudging amendments to his "Relationship Agreement" with his "friend-who-happens-to-be-a-girl" Amy Farrah Fowler, Raj contemplates an arranged marriage, and Howard is all-systems-go for both is NASA space launch and wedding to the spirited Bernadette.

E1The Skank Reflex Analysis
Sep 22, 2011
Penny is worried with how damaged her friendship with the guys will be in the aftermath of her sleeping with Raj while Sheldon becomes the leader of the paintball team.

E2The Infestation Hypothesis
Sep 22, 2011
A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up his long-distance relationship with Priya.

E3The Pulled Groin Extrapolation
Sep 29, 2011
Leonard and Amy get to know each other better, while Howard and Bernadette spend the weekend with Mrs. Wolowitz.

E4The Wiggly Finger Catalyst
Oct 6, 2011
Penny plays Matchmaker for Raj, which results in him finding a girl he is comfortable talking to.

E5The Russian Rocket Reaction
Oct 13, 2011
Sheldon and Leonard get invited to a party at Wil Wheaton's house, and Howard gets an out-of-this-world opportunity.

E6The Rhinitis Revelation
Oct 20, 2011
Sheldon's mother, Mary Cooper, comes to visit, but Sheldon is annoyed that she also spends time with the rest of the gang, instead of catering to his every demand.

E7The Good Guy Fluctuation
Oct 27, 2011
A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to scare the guys for Halloween.

E8The Isolation Permutation
Nov 3, 2011
Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping without her.

E9The Ornithophobia Diffusion
Nov 10, 2011
Leonard and Penny try hanging out as friends on a 'non-date', but end up purposely ruining each others chances with perspective dates. Meanwhile, Sheldon enlists the help of Bernadette and Amy to overcome his fear of birds.

E10The Flaming Spittoon Acquisition
Nov 17, 2011
When Stuart asks Amy out on a date, Sheldon must confront his feelings and consider where his relationship with Amy is going.

E11The Speckerman Recurrence
Dec 8, 2011
Leonard must face his fears after being contacted by his high school tormentor.

E12The Shiny Trinket Maneuver
Jan 12, 2012
Sheldon gets in trouble with Amy when he isn't impressed by her recent accomplishment, and Howard must come to grips with Bernadette's dislike of children.

E13The Recombination Hypothesis
Jan 19, 2012
Leonard, who broke up with Priya, asks Penny out to a spur-of the-moment romantic dinner for two, and the duo contemplates on their relationship.

E14The Beta Test Initiation
Jan 26, 2012
Leonard and Penny deal with the idea of starting a relationship again and Raj finally finds a "woman" he can talk to without being drunk, in the form of Siri on his new phone. Meanwhile, Sheldon decides to start a YouTube series entitled "Sheldon Cooper presents Fun with Flags" with the help of Amy.

E15The Friendship Contraction
Feb 2, 2012
Sheldon's selfish demands force Leonard to reconsider their friendship. Meanwhile, Wolowitz tries to pick his astronaut nickname.

E16The Vacation Solution
Feb 9, 2012
When Sheldon is forced to take his vacation, he goes to work with Amy in her neurobiology lab.

E17The Rothman Disintegration
Feb 16, 2012
Sheldon battles Kripke for a coveted office at the university. Penny receives a very unusual gift from Amy.

E18The Werewolf Transformation
Feb 23, 2012
Sheldon becomes agitated when his regular barber is out sick. Astronaut training causes Howard to reconsider wanting to go into space. Penny beats Leonard in chess, the first time she plays.

E19The Weekend Vortex
Mar 8, 2012
Sheldon must choose between joining Amy at her aunt's birthday party or playing videogames all weekend with the guys.

E20The Transporter Malfunction
Mar 29, 2012
Penny buys Leonard and Sheldon “Star Trek” collectibles as a thank-you, leading Sheldon to be haunted by Mr. Spock. Meanwhile, Raj decides he has met the “Future Mrs. Koothrappali” after his parents set him up on a date.

E21The Hawking Excitation
Apr 5, 2012
When Wolowitz gets to work with Stephen Hawking, Sheldon is willing to do anything to meet his hero.

E22The Stag Convergence
Apr 26, 2012
After the guys throw Howard a bachelor party, Bernadette reconsiders marrying him after learning about his sexual history.

E23The Launch Acceleration
May 3, 2012
When NASA moves up Howard's mission, he must face his fears and Bernadette's dad, thus putting the wedding plans in jeopardy. Meanwhile, Leonard says something surprising to Penny in the bedroom.

E24The Countdown Reflection
May 10, 2012
The fifth season ends with Howard and Bernadette deciding to get married before his NASA mission, causing the gang to scurry into overdrive in an effort to stage the wedding. NASA astronaut Mike Massimino has a cameo as himself.
Whether on or above Earth, hilarity is outrageously universal in TV's most popular comedy featuring four forward-thinking but socially backward geniuses. Fun discoveries multiply: Leonard learns jealousy is bad for a relationship (with Penny) but science is good for seduction (of Penny). Howard finds life in the International Space Station life is no escape from terrestrial turmoil between his mom and his new wife Bernadette. Raj meets someone special who may be a good match, if he can keep her from fleeing mid-date. And then there's Sheldon. He learns what not to say after facing harassment charges or competing for tenure at work and how Dungeons & Dragons can be the icebreaker his relationship with Amy needs.

E1The Date Night Variable
Sep 27, 2012
With his friends on dates, Raj must face his loneliness. Also, Wolowitz is caught in an argument between Bernadette and his mom, even while he’s in space.

E2The Decoupling Fluctuation
Oct 4, 2012
When Sheldon learns that Penny is thinking about breaking up with Leonard, he tries to intervene. Meanwhile, in space, the other astronauts pick on Howard.

E3The Higgs Boson Observation
Oct 11, 2012
Amy feels threatened when Sheldon hires a young female assistant, and the pressure of being in space takes its toll on Wolowitz.

E4The Re-Entry Minimization
Oct 18, 2012
When Wolowitz returns from space, he doesn’t get the hero’s welcome he expected. Meanwhile, Game Night turns into a battle of the sexes.

E5The Holographic Excitation
Oct 25, 2012
The gang celebrates Halloween at Stuart’s comic book store. Meanwhile, Leonard seduces Penny with science.

E6The Extract Obliteration
Nov 1, 2012
Sheldon’s relationship with Stephen Hawking is threatened over a game of “Words with Friends,” and Penny secretly enrolls in a class at the local college.

E7The Habitation Configuration
Nov 8, 2012
Wolowitz struggles with moving out of his mother’s house. Meanwhile, Sheldon is caught in the middle of an argument between Amy and Wil Wheaton.

E8The 43 Peculiarity
Nov 15, 2012
Raj and Howard try to to figure out why Sheldon disappears at 2:45 every afternoon; jealousy arises in Penny and Leonard's relationship.

E9The Parking Spot Escalation
Nov 29, 2012
When the University reassigns Sheldon’s parking spot to Wolowitz, their fight affects the whole gang.

E10The Fish Guts Displacement
Dec 6, 2012
When Amy gets sick, Sheldon tries to nurse her back to health; Wolowitz and his father-in-law plan a fishing trip.

E11The Santa Simulation
Dec 13, 2012
During a Dungeons and Dragons game, Sheldon revisits Christmas memories; Amy, Penny and Bernadette look for a date for Raj.

E12The Egg Salad Equivalency
Jan 3, 2013
When Sheldon is accused of sexual harassment, he ends up getting Raj, Leonard and Howard in trouble.

E13The Bakersfield Expedition
Jan 10, 2013
As the guys don costumes and go on a road trip to a comic book convention, the ladies decide to stay home and try to interpret a comic book.

E14The Cooper/Kripke Inversion
Jan 31, 2013
Sheldon faces a crisis of confidence when he is forced to work with his nemesis, Barry Kripke; Raj and Howard buy expensive action figures of themselves.

E15The Spoiler Alert Segmentation
Feb 7, 2013
A fight between Sheldon and Leonard impacts Amy and Penny's living arrangements; while Howard is away, Raj helps Mrs. Wolowitz out.

E16The Tangible Affection Proof
Feb 14, 2013
The guys search for a perfect Valentine's Day gift for their significant others; Stuart and Raj host a "lonely people" party at the comic book store.

E17The Monster Isolation
Feb 21, 2013
After a bad date, Koothrappali decides to never leave his apartment; Penny's acting skills impress Sheldon.

E18The Contractual Obligation Implementation
Mar 7, 2013
Leonard, Sheldon and Howard give lectures on science to junior high students. The girls ditch work to go to Disneyland. Raj devises a date for Lucy that fixes their social anxiety problems.

E19The Closet Reconfiguration
Mar 14, 2013
Howard considers whether or not he should open a letter from his father; Penny and Leonard host a "grown-up" cocktail party.

E20The Tenure Turbulence
Apr 4, 2013
The girls get involved when Leonard, Sheldon and Raj compete for tenure at the University.

E21The Closure Alternative
Apr 25, 2013
Amy tries to help Sheldon get over his compulsive need for closure when one of his favorite TV shows is canceled; Raj discovers a secret about Lucy.

E22The Proton Resurgence
May 2, 2013
Leonard and Sheldon hire the host (Bob Newhart) of their favorite childhood TV show to perform; Bernadette and Howard run into trouble while dog-sitting for Raj's pet.

E23The Love Spell Potential
May 9, 2013
A date between Raj and Lucy takes both of them out of their comfort zones. After a trip to Las Vegas goes awry, the girls join in on a Dungeons and Dragons game, which causes Amy and Sheldon to re-evaluate their relationship.

E24The Bon Voyage Reaction
May 16, 2013
When Leonard receives an exciting opportunity to work overseas, Penny and Sheldon are thrown for a loop. Raj and Lucy's relationship comes to a crossroad.
Leonard returns from his North Sea expedition to find that his relationship with Penny involves more beta-testing than he’s ever done in a lab. Howard’s attachment issues with the women in his life in particular and Raj’s social breakthrough with women in general provide more laughs. Bernadette and Amy stand staunchly by the men in their life, even when they’re sitting in marathon role-playing games. Sheldon sees his mom in a totally different way, parties with James Earl Jones, establishes a (sort of) bond with his idol Professor Proton and makes a scientific breakthrough that breaks down before you can say Science Friday.

E1The Hofstadter Insufficiency
Sep 26, 2013
With Leonard away, Sheldon and Penny spend quality time together sharing intimate secrets. Also, Wolowitz helps Raj get over his ex-girlfriend.

E2The Deception Verification
Sep 26, 2013
Leonard and Sheldon's friendship is tested; Howard's latest foray into helping his mother has some disastrous side effects.

E3The Scavenger Vortex
Oct 3, 2013
When the entire gang competes in a scavenger hunt designed by Raj, it brings out the best - and worst - in everyone.

E4The Raiders Minimization
Oct 10, 2013
Sheldon gets mad at Amy for ruining one of his favorite movies, Raj and Stuart try to make their online dating profiles more appealing, and Leonard tries to play the sympathy card with Penny.

E5The Workplace Proximity
Oct 17, 2013
Amy starts working at Caltech which causes friction with Sheldon. Howard agrees with Sheldon who mentions this to Bernadette causing a big fight for the Wolowitzes.

E6The Romance Resonance
Oct 24, 2013
Sheldon's latest scientific breakthrough leaves him feeling like a fraud; a romantic gesture between Howard and Bernadette causes Penny to up her game with Leonard.

E7The Proton Displacement
Nov 7, 2013
Sheldon seeks payback when Arthur "Professor Proton" Jeffries asks Leonard for help on a project instead of him. Raj gets upset at Howard for crashing his night with the girls.

E8The Itchy Brain Simulation
Nov 14, 2013
When a mistake comes to light, Sheldon makes Leonard walk a mile in his shoes; Penny decides to confront Raj's ex-girlfriend, Lucy.

E9The Thanksgiving Decoupling
Nov 21, 2013
Sheldon protests when the gang drags him to Mrs. Wolowitz’s house for Thanksgiving. Meanwhile, Penny and Leonard must deal with a mistake from her past.

E10The Discovery Dissipation
Dec 5, 2013
Leonard has to deal with the fallout of disproving Sheldon's new scientific discovery. Raj spends a week at Howard and Bernadette's apartment.

E11The Cooper Extraction
Dec 12, 2013
While Sheldon is at home in Texas, the rest of the gang realizes how much he has changed their lives as they decorate the apartment Christmas tree.

E12The Hesitation Ramification
Jan 2, 2014
When Penny’s big acting break on NCIS is a bust, Leonard struggles to help her, which results in Penny asking Leonard a bold relationship question. Meanwhile, Raj and Stuart try to practice their social skills, and Sheldon navigates the intricacies of being funny.

E13The Occupation Recalibration
Jan 9, 2014
Sheldon tries to relax after he is forced to take a vacation. Meanwhile, Leonard struggles to be supportive of Penny after she quits her job, and Bernadette seeks Stuart’s help in replacing one of Howard’s comic books. Also, Amy receives an unwanted attention from a co-worker.

E14The Convention Conundrum
Jan 30, 2014
After the guys can’t get Comic-Con tickets, Sheldon tries to hold his own convention and winds up spending a wild night with James Earl Jones. Meanwhile, the girls try to feel more mature by going to a fancy hotel for tea.

E15The Locomotive Manipulation
Feb 6, 2014
Sheldon and Amy take a train ride to Napa Valley with Howard and Bernadette on Valentine's Day. Leonard and Penny take Raj's dog to the vet when she accidentally eats some chocolate.

E16The Table Polarization
Feb 27, 2014
Leonard buys a dining room table and it causes Sheldon to reevaluate the changes in his life. Meanwhile, Wolowitz is offered a chance to go back to space and Bernadette struggles with whether or not to encourage him.

E17The Friendship Turbulence
Mar 6, 2014
After arguing with Sheldon, Howard tries to make amends by taking him to NASA headquarters in Houston. Penny has second thoughts about quitting her waitressing job when her car dies. Amy gets involved in trying to find Raj a date.

E18The Mommy Observation
Mar 13, 2014
When Sheldon visits his Mom in Houston, he is forced to confront a new reality. Meanwhile, Raj’s ‘Murder Mystery’ party starts some fights within the gang.

E19The Indecision Amalgamation
Apr 3, 2014
While Raj is wracked with guilt when he tries to date two women at once, Penny wrestles with whether to take a role in a cheesy movie and Sheldon is torn trying to choose between two gaming systems.

E20The Relationship Diremption
Apr 10, 2014
Sheldon faces a personal crisis after deciding he’s wasting his time with string theory. Meanwhile, a double date between Raj, Emily and the Wolowitzes ends in embarrassment for Howard.

E21The Anything Can Happen Recurrence
Apr 24, 2014
To prepare for a date with Emily, Howard acclimates Raj to horror movies. Penny and Sheldon are upset when they discover Amy and Bernadette lied to avoid hanging out with them.

E22The Proton Transmogrification
May 1, 2014
As the gang celebrates Star Wars Day, Sheldon has difficulty dealing with the recent death of Arthur "Professor Proton" Jeffries.

E23The Gorilla Dissolution
May 8, 2014
A bad day causes Penny to reevaluate her life choices – including Leonard. Meanwhile, Howard and Bernadette struggle to care for Mrs. Wolowitz, and Raj gets relationship advice from Sheldon.

E24The Status Quo Combustion
May 15, 2014
Sheldon get upset about his career, the destruction of the comic book store and Leonard and Penny's future living arrangements. Howard and Bernadette can't keep hold of a caretaker for his mother. With his entire world changing around him, Sheldon considers a major move.
Sheldon is rescued from his soul-searching cross-country train trip (older but no wiser) and that means The Big Bang Theory gang's all here to spread another gear's cheer as TV's most attended laugh seminar. Enrol in the comic curriculum to observe Leonard's minor surgery, which signals a major catastrophe for Sheldon, Howard's obsession over his mum's relationship with friend-turned-freeloader Stuart and the unexpected results of Penny's technique as a pharmaceutical sales rep. Discover ways to re-create proms not attended or holiday celebrations not especially beloved and play a new game based on Raj's dating life. Savour online fan Fiction by Amy, watch Bernadette take indelicate command of some delicate family matters and, who knows, you might spot a cool special guest or two.

E1The Locomotion Interruption
Sep 22, 2014
Leonard and Amy make an unexpected trip to Arizona to fetch Sheldon; Penny interviews for a job at Bernadette's company; Stuart's relationship with Mrs. Wolowitz disturbs Howard.

E2The Junior Professor Solution
Sep 22, 2014
Sheldon is forced to teach a class as a Junior Professor and Howard decides to enroll in it. Meanwhile, Amy plays both sides when tension arises between Penny and Bernadette.

E3The First Pitch Insufficiency
Sep 29, 2014
Wolowitz feels nervous when he is asked to throw the first pitch at a Los Angeles Angels game. Penny and Leonard want to prove Sheldon wrong after he says he and Amy are the better couple.

E4The Hook-Up Reverberation
Oct 6, 2014
Raj's honesty comes back to haunt him when his new girlfriend is unfriendly to Penny. The guys think about becoming part owners in Stuart's store.

E5The Focus Attenuation
Oct 13, 2014
The girls head to Las Vegas for some weekend fun, while the guys try to invent something cool, but only come up with new ways to procrastinate.

E6The Expedition Approximation
Oct 20, 2014
Sheldon and Raj test whether they could survive a dark-matter research expedition in a salt mine by simulating the conditions in a steam tunnel deep underground. Meanwhile, Leonard and Penny seek advice from Howard and Bernadette after they fight about money.

E7The Misinterpretation Agitation
Oct 30, 2014
The guys try to help Penny out of an awkward work dilemma, when a smitten doctor shows up at her door after her flirtatious sales techniques work a little too well. Meanwhile, Amy and Bernadette argue over whether or not female scientists should play up their sexuality.

E8The Prom Equivalency
Nov 6, 2014
The girls decide to re-enact their high school proms with the guys. While Sheldon feels under pressure to commit to his relationship with Amy, Howard worries about who Stuart will bring as his date.

E9The Septum Deviation
Nov 13, 2014
When Leonard gets minor surgery on his nose, Sheldon is the one in need of sympathy. Meanwhile, Raj's parents' impending divorce causes Howard and Bernadette to work on their own marriage.

E10The Champagne Reflection
Nov 20, 2014
While Sheldon says a tearful goodbye to the final installment of "Fun with Flags", Leonard, Howard and Raj search for something significant in a dead professor's research. And Bernadette finds out what her colleagues really think of her.

E11The Clean Room Infiltration
Dec 11, 2014
Leonard and Howard turn to Raj for help in dealing with a work emergency when they nearly come to blows after blaming each other for a potential disaster at the university. Amy throws an authentic Victorian Christmas party, while Sheldon seeks revenge on her for making him celebrate the holidays.

E12The Space Probe Disintegration
Jan 8, 2015
Howard tries to distract Raj, who is anxiously awaiting data from a space probe he helped launch. Meanwhile, Sheldon and Leonard go dress shopping with Penny and Amy.

E13The Anxiety Optimization
Jan 29, 2015
When Sheldon becomes stuck in a rut with his work, the gang tries to help him by raising his stress levels. Howard teases Raj with a game called "Emily or Cinnamon?"

E14The Troll Manifestation
Feb 5, 2015
Leonard and Sheldon publish a paper which is widely accepted except for comments from an internet troll. Meanwhile, the girls reminisce about embarrassing incidents from their past.

E15The Comic Book Store Regeneration
Feb 19, 2015
Howard receives some shocking news as everyone prepares for the reopening of Stuart’s comic book store. Penny teaches Sheldon how to “let it go,” but can’t follow her own advice after she learns something infuriating about Amy. Also, Leonard and Raj think they spot Nathan Fillion at a restaurant.

E16The Intimacy Acceleration
Feb 26, 2015
As a joke, Sheldon and Penny try an experiment designed to make participants fall in love. Meanwhile, Leonard, Amy, Raj and Emily spend the evening trying to escape a room with a “zombie.” And, after returning from Mrs. Wolowitz’ funeral, Bernadette and Howard run into trouble at the airport.

E17The Colonization Application
Mar 5, 2015
A trip to the pet store ends in a fight after Amy learns Sheldon has applied for a one-way mission to colonize Mars. Meanwhile, Leonard surprises Penny with a very "adult" purchase, and Raj gets into trouble when he snoops around Emily's apartment.

E18The Leftover Thermalization
Mar 12, 2015
Friction ensues when a magazine fails to mention Leonard in an article about the paper he co-wrote with Sheldon. Also, a blackout at Mrs. Wolowitz’s home leads to a final family dinner in her honor.

E19The Skywalker Incursion
Apr 2, 2015
When Leonard and Sheldon are invited to speak at UC Berkeley, they take a detour to try to meet an idol. Also, when Bernadette and Howard battle over the fate of his Doctor Who TARDIS, Raj and Amy offer to settle the dispute with a game of ping pong.

E20The Fortification Implementation
Apr 9, 2015
When Sheldon and Amy build a blanket fort, they come to major crossroads in their relationship. Also, Howard meets the half-brother he never knew he had. Meanwhile, Penny is invited to appear on Wil Wheaton’s podcast, but things turn awkward when Leonard joins them.

E21The Communication Deterioration
Apr 16, 2015
When Raj is asked to create a message in case a NASA mission discovers alien life, the guys fight over what he should do. Also, Penny is torn between auditioning for a movie or keeping her successful pharmaceutical sales job.

E22The Graduation Transmission
Apr 23, 2015
Howard questions his engineering abilities when he and Sheldon can’t get a toy drone to fly. Meanwhile, a cancelled flight nearly prevents Leonard from giving the commencement address at his former high school, and Raj pits his parents against each other when his father cuts him off financially.

E23The Maternal Combustion
Apr 30, 2015
Personalities collide when Sheldon and Leonard’s mothers finally meet. Meanwhile, Howard finally decides to “man up” and do his fair share of the housework – but not without a little help from his friends.

E24The Commitment Determination
May 7, 2015
As Sheldon presses Leonard and Penny to set a wedding date, he encounters major changes in his own relationship with Amy. Meanwhile, Raj contemplates breaking up with Emily, and Howard and Bernadette struggle with asking Stuart to move out of their house.
Our two genius roommates, Leonard and Sheldon, and their friends are back once again (smarter, but no wiser). Last season, Sheldon went soul-searching (on a train, of course) and was prepared to make some substantial revisions on his Relationship Agreement with Amy, when everything changed. Leonard, meanwhile, was off to Vegas with Penny to finally tie the knot in the season finale. Howard finds himself alone with Bernadette after the sudden passing of his mother; while Raj is not only talking to women – he’s getting exclusive with Emily. Together, they will all learn that life is far more complicated outside of the lab as love and friendship never produce predictable results!

E1The Matrimonial Momentum
Sep 21, 2015
After driving to Vegas to get married, Penny struggles with Leonard’s confession that he kissed another girl. Also, Sheldon doesn't know how to act after Amy pushes pause on their relationship.

E2The Separation Oscillation
Sep 28, 2015
Leonard confronts the woman he kissed on the North Sea in an attempt to set Penny's mind at ease. Also, Sheldon films a special episode of "Fun with Flags" after his breakup with Amy, and Bernadette feels guilty about withholding a secret from Penny.

E3The Bachelor Party Corrosion
Oct 5, 2015
The guys' science skills are put to the test when they get a flat tire during Leonard's bachelor party weekend in Mexico. Also, the girls force Penny to finally tell her family that she eloped with Leonard.

E4The 2003 Approximation
Oct 12, 2015
Sheldon learns of an impending change in his living arrangements and decides to revert back to 2003, a simpler time before he met Leonard and Penny. Also, Howard and Raj form a band to play at the Comic Book Store.

E5The Perspiration Implementation
Oct 19, 2015
The guys take a fencing lesson from Barry Kripke and Sheldon finds himself in an awkward position when Kripke expresses interest in Amy. Also, when Stuart struggles to get female customers at the Comic Book Store, Penny, Amy and Bernadette come by to help him out.

E6The Helium Insufficiency
Oct 26, 2015
In the midst of a nation-wide helium shortage, Sheldon and Leonard take desperate measures to get the supplies they need. Also, Penny and Bernadette download a dating app on Amy's phone to try and find her a new man.

E7The Spock Resonance
Nov 5, 2015
Wil Wheaton interviews Sheldon for a Star Trek documentary where he reveals the ring and his plan to propose to Amy. Bernadette wants to start renovating the house and the topic of starting a family together with Howard is brought up.

E8The Mystery Date Observation
Nov 12, 2015
Sheldon, Wolowitz and Koothrappali post an online advertisement to find Sheldon a new girlfriend. Also, when Amy is coy with details about a guy she is dating, Penny and Bernadette decide to spy on her.

E9The Platonic Permutation
Nov 19, 2015
Sheldon and Amy try hanging out as friends when they spend Thanksgiving together at the aquarium. Also, Wolowitz reluctantly agrees to volunteer at the soup kitchen with Bernadette, Raj and Emily, and Penny discovers that Leonard knows more about her than she thought.

E10The Earworm Reverberation
Dec 10, 2015
Sheldon has a revelation when he realizes why a song was stuck in his head. Also, Amy invites Dave over for dinner despite their previously awkward date, and Wolowitz and Koothrappali become obsessed with a fan of their band, "Footprints on the Moon".

E11The Opening Night Excitation
Dec 17, 2015
After more than five years of dating, Sheldon and Amy spend their first night together. Also, Leonard, Wolowitz, and Koothrappali must decide who will take their extra Star Wars movie ticket.

E12The Sales Call Sublimation
Jan 7, 2016
Penny gets more than she bargained for when Leonard agrees to meet with a psychiatrist on her behalf. Also, Sheldon and Koothrappali collaborate on an astronomical discovery, and Wolowitz and Bernadette can't believe what they are feeling after Stuart moves out.

E13The Empathy Optimization
Jan 14, 2016
After having to deal with a sick Sheldon, Leonard, Penny and the gang try to treat themselves to a Sheldon-free weekend.

E14The Meemaw Materialization
Feb 4, 2016
Meemaw meets Amy, but it isn't all roses. Meemaw seems to have an axe to grind with her. Sheldon comes to Amy's defense, but not before Meemaw lets a little secret of his slip.

E15The Valentino Submergence
Feb 11, 2016
Sheldon and Amy host a live Valentine's Day episode of Fun with Flags, Leonard and Penny grapple with getting older, Howard and Bernadette find a surprise in their hot tub and Raj is torn between Emily and the cute girl he met at the Comic Bookstore.

E16The Positive Negative Reaction
Feb 18, 2016
When the gang finds out about Bernadette’s pregnancy, they celebrate by singing karaoke. Also, Bernadette is concerned when Wolowitz freaks out over her pregnancy announcement, and Wolowitz is convinced he must make more money to provide for the baby.

E17The Celebration Experimentation
Feb 25, 2016
After more than nine years together, the gang finally celebrates Sheldon’s birthday, surprising him with a special guest.

E18The Application Deterioration
Mar 10, 2016
Leonard, Sheldon, and Wolowitz run into problems when they file for a patent for their infinite persistence gyroscope. Also, Penny, Amy and Bernadette give Koothrappali dating advice when Emily reaches out to him after their breakup.

E19The Solder Excursion Diversion
Mar 31, 2016
Amy is shocked at a revelation from Sheldon after she buys him a new laptop. Also, Koothrappali sells out Leonard and Wolowitz after they lie to their wives in order to attend an early screening of a movie.

E20The Big Bear Precipitation
Apr 7, 2016
Sheldon spills a secret of Leonard’s when the two take a weekend cabin trip with Penny and Amy. Also, when Koothrappali goes overboard with pregnancy gifts, Wolowitz and Bernadette must draw the line.

E21The Viewing Party Combustion
Apr 21, 2016
Everyone must choose sides when a small argument between Leonard and Sheldon erupts into a heated fight during a group get-together.

E22The Fermentation Bifurcation
Apr 28, 2016
The gang goes to a wine bar and runs into Penny’s old boyfriend, Zack. Also, Bernadette gets stuck spending the evening with Sheldon when she can’t go wine tasting with the group, and things don’t go as planned when Koothrappali introduces his new girlfriend, Claire.

E23The Line Substitution Solution
May 5, 2016
Sheldon hires Stuart to spend the day with Amy when he’d rather go to a movie screening. Also, Leonard’s mother, Beverly, comes to town and Penny struggles to make a connection with her.

E24The Convergence Convergence
May 12, 2016
Chaos ensues when Leonard’s recently divorced parents, Alfred and Beverly, and Sheldon’s devoutly religious mother, Mary, come to town. Also, Wolowitz and Koothrappali think the government is out to get them when they are contacted about their guidance system.
Leonard and Penny renew their vows, this time inviting their friends and family for wedding party; they also learn that marriage is about compromise, and figure out how to support each other. Sheldon and Amy experiment to take their relationship to the next level, and after an emotional struggle they move in together in Penny's old apartment. Howard and Bernadette realise that being a parent is a full-time job, but with the help of their friends they manage to find joy in raising their child. When his friends tell him he's extremely spoiled, Raj decides to stop taking his father's money and learn how to make ends meet.

E1The Conjugal Conjecture
Sep 19, 2016
After Sheldon’s mother and Leonard's father share an evening together, everyone deals with an awkward morning the next day. Also, Penny’s family arrives for the wedding ceremony, including her anxiety-ridden mother, Susan, and her drug dealing brother, Randall.

E2The Military Miniaturization
Sep 26, 2016
Colonel Williams, an Air Force representative from the Department of Material Command sits down to talk with Wolowitz.

E3The Dependence Transcendence
Oct 3, 2016
Tensions rise when the boys struggle to complete their government project on time and Sheldon tries an energy drink to stay awake. Also, Penny and Amy go to a “party” at Bert the geologist’s house, and Koothrappali learns Bernadette’s true feelings about her pregnancy when they clean out the future baby room.

E4The Cohabitation Experimentation
Oct 10, 2016
When Amy’s apartment floods, she proposes a “cohabitation experiment” with Sheldon. Also, Howard and Bernadette are upset when Koothrappali learns the gender of the baby before they do.

E5The Hot Tub Contamination
Oct 17, 2016
Leonard and Penny must separate a quarreling Sheldon and Amy when their cohabitation does not go as planned, and Sheldon threatens to break off their relationship when Amy refuses to adhere to the bathroom schedule. Also, Howard and Bernadette find unexpected guests at their house when they decide to stay home from a planned vacation.

E6The Fetal Kick Catalyst
Oct 27, 2016
Penny is surprised to learn she has fans of her performance in "Serial Ape-ist" when she attends Van Nuys Comic Con with Leonard. Also, Amy hosts a Sheldon-style brunch at Penny’s apartment, and Wolowitz makes an impulsive purchase when he starts stressing out about the baby on the way.

E7The Veracity Elasticity
Nov 3, 2016
In order to continue living with Sheldon, Amy lies to him about repairs being made to her apartment and they host an "on location" episode of "Fun With Flags" in Penny’s apartment. Also, Leonard lets Penny decorate Sheldon’s old room after he learns that she has been secretly moving Leonard’s collectibles into storage.

E8The Brain Bowl Incubation
Nov 10, 2016
After a successful experiment combining their genes, Sheldon will stop at nothing to convince Amy they should procreate. Also, Koothrappali is embarrassed to tell the gang what the new woman he’s dating does for a living.

E9The Geology Elevation
Nov 17, 2016
When Bert, a Caltech geologist, wins the MacArthur Genius fellowship, Sheldon is overcome with jealousy. Also, Wolowitz finds an old remote control Stephen Hawking action figure he invented.

E10The Property Division Collision
Dec 1, 2016
Sheldon and Leonard try to divvy up their shared belongings, but can’t agree on anything. Also, Koothrappali and Stuart fight to be the most helpful during Bernadette’s final weeks of pregnancy.

E11The Birthday Synchronicity
Dec 15, 2016
Howard and Bernadette welcome their new baby and Sheldon and Amy celebrate Amy’s birthday.

E12The Holiday Summation
Jan 5, 2017
Sheldon and Amy visit Leonard and Penny for the first time since the holidays and share details about their terrible trip to Texas.

E13The Romance Recalibration
Jan 19, 2017
When Penny feels that Leonard is taking her for granted, she decides to go on a spa weekend with Amy. Also, Wolowitz and Koothrappali try to fix a squeaky floorboard in the baby’s room.

E14The Emotion Detection Automation
Feb 2, 2017
Sheldon beta-tests an MIT invention after hearing it can help him read people’s emotions. Also, Leonard can’t hide his feelings when Penny announces her brother is coming to town, and Raj invites his ex-girlfriends over to give him dating advice.

E15The Locomotion Reverberation
Feb 9, 2017
Leonard and Wolowitz try to distract Sheldon when he slows the progress of their guidance system. Also, Penny and Amy take Bernadette out for the night, leaving Raj and Stuart to care for baby Halley.

E16The Allowance Evaporation
Feb 16, 2017
Sheldon and Amy have their first fight since moving in together, and Koothrappali is shocked at the realities of financial independence when he stops receiving support from his father.

E17The Comic-Con Conundrum
Feb 23, 2017
With Koothrappali cut off from his father’s fortune, he appoints Sheldon to help him get out of debt. Also, Penny considers joining Leonard at Comic-Con.

E18The Escape Hatch Identification
Mar 9, 2017
When Raj moves out of his apartment, Leonard and Penny offer him Sheldon's old room.

E19The Collaboration Fluctuation
Mar 30, 2017
Leonard, Penny and Raj adjust to their new living arrangement, and Sheldon takes an interest in Amy’s work.

E20The Recollection Dissipation
Apr 6, 2017
Sheldon pushes himself to the limit when he collaborates on projects with Leonard and Wolowitz as well as Amy on the same day. Also, Bernadette is nearing the end of her maternity leave and must return to work.

E21The Separation Agitation
Apr 13, 2017
Howard and Bernadette have a hard time leaving Halley in day care when Bernadette returns to work. Also, Bert introduces the gang to his new girlfriend, Rebecca.

E22The Cognition Regeneration
Apr 27, 2017
Leonard isn’t thrilled when Penny considers taking a new job offered by her ex-boyfriend, Zack.

E23The Gyroscopic Collapse
May 4, 2017
After Leonard, Sheldon and Wolowitz celebrate the completion of the top secret air force project, they are met with an unpleasant surprise. Also, Amy is offered a summer position as a visiting researcher.

E24The Long Distance Dissonance
May 11, 2017
The gang is concerned when Sheldon’s former admirer, Dr. Ramona Nowitzki, resurfaces while Amy is away at Princeton.
After years of only looking out for himself, Sheldon found Amy Farrah Fowler to be the most patient woman to ever walk the earth, and... they did it! Wedding fever continues in season 11.

E1The Proposal Proposal
Sep 25, 2017
In the eleventh season opener, Amy gives Sheldon an answer to his proposal while Howard and Bernadette struggle with some unexpected news.

E2The Retraction Reaction
Oct 2, 2017
Leonard angers the university – and the entire physics community – after he gives an embarrassing interview. Also, Amy and Bernadette bond over having to hide their success from Sheldon and Howard.

E3The Relaxation Integration
Oct 9, 2017
Sheldon and Amy struggle with picking a wedding date, which stresses out Sheldon and causes him talking in his sleep. Meanwhile, Raj and Stuart fight over the attention of one of Bernadette's co-workers.

E4The Explosion Implosion
Oct 16, 2017
As Howard worries about fatherhood, he and Sheldon bond when they jointly assemble a model rocket. Meanwhile, Penny bonds with Leonard's mother, Beverly, much to his concern.

E5The Collaboration Contamination
Oct 23, 2017
Sheldon and Raj confide in Bernadette when they can't handle Amy and Howard working together on a science project. Also, Penny and Leonard learn new tactics for how to deal with Sheldon from an unlikely source.

E6The Proton Regeneration
Nov 2, 2017
Sheldon goes head-to-head with Wil Wheaton for the role of the new Professor Proton. Also, Penny steps in to take care of Halley when Bernadette and Howard both wind up on bed rest.

E7The Geology Methodology
Nov 9, 2017
Sheldon and Bert collaborate on a research project, despite Sheldon’s embarrassment. Also, Penny and Bernadette coach Raj on how to navigate his relationship with Ruchi.

E8The Tesla Recoil
Nov 16, 2017
Leonard and Howard are furious after they learn Sheldon went to work with the military behind their backs. Also, while Bernadette is on bed rest, she asks Raj to do some digging when she suspects that Ruchi might be trying to take over her projects at work.

E9The Bitcoin Entanglement
Nov 30, 2017
Sheldon tries to teach the guys a lesson after they cut him out of a potentially valuable Bitcoin investment. Also, a seven-year-old video reveals a secret about Leonard and Penny's relationship.

E10The Confidence Erosion
Dec 7, 2017
Sheldon and Amy try to eliminate stress from wedding planning by applying math to the process. Also, Raj “breaks up” with Howard after realizing his best friend is actually hurting his confidence.

E11The Celebration Reverberation
Dec 14, 2017
Raj and Howard's feud continues as the gang plan Halley's first birthday party. Sheldon's surprise for Amy's birthday goes awry when they get food poisoning. Also, Leonard gets a Christmas letter from his brother that causes him to spiral out about his own lack of accomplishments.

E12The Matrimonial Metric
Jan 4, 2018
Sheldon and Amy try to pick their Best-Man and Maid of Honor by experimenting on the gang.

E13The Solo Oscillation
Jan 11, 2018
When Sheldon kicks Amy out to work solo, she and Leonard bond during a series of science experiments. Also, Bert the geologist replaces Wolowitz in the band Footprints on the Moon, and Sheldon finds Penny a surprising source of scientific inspiration.

E14The Separation Triangulation
Jan 18, 2018
Raj finds himself in the middle of domestic drama when he learns the woman he's dating, has a very upset husband. Also, when Sheldon rents his old room back for a quiet place to work, he drives Leonard crazy by being a model tenant.

E15The Novelization Correlation
Feb 1, 2018
Leonard's book raises questions, and Amy guest stars on the new Professor Proton show.

E16The Neonatal Nomenclature
Mar 1, 2018
When Bernadette won't go into labor, the gang tries different tactics to get things started. Also, Howard confronts Bernadette after Amy accidentally reveals she's already chosen their son's name.

E17The Athenaeum Allocation
Mar 8, 2018
Leonard jumps through hoops to help secure the perfect wedding venue for Sheldon and Amy. Also, Bernadette and Howard have a hard time deciding who should stay at home with the kids and who should go back to work.

E18The Gates Excitation
Mar 29, 2018
Bill Gates visits Penny's work, and the gang schemes to meet him. Hilarity ensues. Meanwhile, Sheldon is convinced that he's a target of an April's Fools prank.

E19The Tenant Disassociation
Apr 5, 2018
When Leonard learns Sheldon is the president of the tenants association, he decides to run against him. Also, Bernadette encourages Howard and Raj to find the owner of a drone after they find it in the backyard.

E20The Reclusive Potential
Apr 12, 2018
A brilliant but reclusive scientist, Doctor Wolcott, invites Sheldon to his cabin in the middle of nowhere, and Leonard, Raj and Howard go along for the trip. Also, Penny and Bernadette improvise after Amy doesn’t like the tame bachelorette party they planned for her.

E21The Comet Polarization
Apr 19, 2018
Sheldon’s comic book store experience changes when writer Neil Gaiman puts Stuart’s store on the map. Also, friendships are threatened when Raj takes credit for Penny's astronomical discovery.

E22The Monetary Insufficiency
Apr 26, 2018
Sheldon goes to Vegas to win money for science. Also, Penny and Bernadette take Amy wedding dress shopping, but her terrible choice entangles them in a web of lies.

E23The Sibling Realignment
May 3, 2018
When Sheldon learns that his mother won’t attend his wedding unless he invites his brother, Georgie, he and Leonard travel to Texas to end a family feud. Also, the Wolowitz kids inadvertently infest Amy, Bernadette, Howard and Raj with pinkeye.

E24The Bow Tie Asymmetry
May 10, 2018
When Amy's parents and Sheldon's family arrive, everybody is focused to make sure all wedding arrangements go according to plan – everyone except the bride and groom.
Best friends and brilliant physicists Leonard Hofstadter and Sheldon Cooper are geniuses in the lab but socially challenge outside of it. Despite this, Leonard married his beautiful, street-smart neighbour, Penny. And Sheldon, after a long courtship, wed successful neurobiologist Amy. And while aerospace engineer Howard and his adorable microbiologist wife, Bernadette, explore the predicament of being married with two kids, astrophysicist Raj considers a traditional arranged marriage. As the supersmart friends solve quotidian conundrums posed by academia. Family crises and video games, their experiments in domestic bliss never fail to produce hilarious results. But all good theories arrive at a conclusion. The twelfth and final season of "television's perpetual laughter continuum comprises" 24 supercharged episodes that take comedy to the next dimension...and beyond.

E1The Conjugal Configuration
Sep 24, 2018
Sheldon and Amy's honeymoon runs aground in New York. Penny and Leonard discover they are uncomfortably similar to Amy's parents. Raj insults physicist Neil deGrasse Tyson and starts a Twitter war.

E2The Wedding Gift Wormhole
Sep 27, 2018
Sheldon and Amy drive themselves crazy trying to figure out what 'perfect gift' Leonard and Penny gave them for their wedding. Raj decides he wants to settle down and asks his father to arrange a marriage for him.

E3The Procreation Calculation
Oct 4, 2018
The Wolowitzes' life gets complicated when Stuart starts bringing his new girlfriend home. Also, Penny and Leonard talk about starting a family, while Raj explores an arranged marriage.

E4The Tam Turbulence
Oct 11, 2018
When Sheldon won't tell anyone why he's never mentioned his childhood best friend, Leonard takes matters into his own hands. Bernadette and Penny take out Raj’s fiancée for dinner to get the skinny on her.

E5The Planetarium Collision
Oct 18, 2018
When Amy doesn’t have time to work on super-asymmetry, Sheldon goes to great lengths to ensure she’s available to work with him even it if means accidentally sabotaging her career in the process. Raj doesn’t want Howard to join him in hosting a show at the planetarium.

E6The Imitation Perturbation
Oct 25, 2018
When Howard dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny's Halloween party. Leonard is shocked that Penny doesn't remember their first kiss.

E7The Grant Allocation Derivation
Nov 1, 2018
Leonard is caught between a rock and a hard place when he's responsible for distributing extra grant money. Bernadette turns the backyard playhouse into a hideaway from Howard and the kids.

E8The Consummation Deviation
Nov 8, 2018
Sheldon tries to bond with Amy's father, but when Howard lures Mr. Fowler away with magic tricks, Sheldon has no choice but to bond with Mrs. Fowler. Raj and Anu try to get physical for the first time.

E9The Citation Negation
Nov 15, 2018
Sheldon and Amy are devastated after learning from a Russian paper that Super Asymmetry has already been theorized and disproven. Meanwhile, ultra-competitive Bernadette asks Stuart’s girlfriend to teach her how to beat Howard in a popular video game.

E10The VCR Illumination
Dec 6, 2018
Sheldon and Amy are still down about their theory being disproven, but a VHS tape from Sheldon’s past inspires him not to give up. Bernadette turns into a pageant mom when she tries to help Howard ace his Magic Castle audition.

E11The Paintball Scattering
Jan 3, 2019
Penny and Leonard organize a paintball game that results in mayhem when Sheldon is jealous of Amy. Also, Raj catches Anu with her ex-boyfriend, and Stuart gets cold feet when Denise hints at the possibility of them living together.

E12The Propagation Proposition
Jan 10, 2019
Penny runs into her ex-boyfriend, Zack, who invites her and Leonard to a dinner to meet his newlywed wife. After the dinner the newlywed couple make an odd proposition to Leonard, which makes Penny to freak out. Also, Raj attempts to mend things with his ex-fiancée, Anu.

E13The Confirmation Polarization
Jan 17, 2019
Sheldon and Amy are thrilled when their super asymmetry theory is proven by two physicists, until they try to kick Amy off the Nobel nomination. Also, Bernadette gets one of her drugs approved at work and wants a reluctant Penny to head the sales team.

E14The Meteorite Manifestation
Jan 31, 2019
Sheldon is thrilled to help Bernadette and Wolowitz navigate bureaucratic paperwork, until he discovers they are breaking the law. Also, Leonard is disappointed when his friends exclude him from a scientific project.

E15The Donation Oscillation
Feb 7, 2019
Penny tries to seduce an abstaining Leonard to ruin his "donation" for her ex-boyfriend, Zack, and his wife, Marissa. Also, Wolowitz, Bernadette, Anu and Koothrappali turn Koothrappali's canceled bachelor party into a couple's trip.

E16The D & D Vortex
Feb 21, 2019
The gang finds out Wil Wheaton hosts a celebrity Dungeons and Dragons game involving William Shatner, Joe Manganiello, Kareem Abdul-Jabbar and Kevin Smith. Deception and betrayal are the path to make it to the one open seat.

E17The Conference Valuation
Mar 7, 2019
When Penny and Bernadette go to San Diego for a pharmaceutical sales convention, Wolowitz is in charge of the kids. Also, Sheldon finds a book on experimenting on kids, and the guys plus Amy make a day of it.

E18The Laureate Accumulation
Apr 4, 2019
When competitors Pemberton and Campbell charm America on a publicity tour, Sheldon and Amy try to bring Nobel laureates Kip Thorne, George Smoot and Frances Arnold to their side. Also, Halley's fear of the dark causes opportunity and conflict at the Wolowitz home.

E19The Inspiration Deprivation
Apr 18, 2019
The concept of what it would mean for women everywhere if Amy were to win a Nobel Prize causes Amy to have a meltdown. Also, Howard and Raj try to relive the good old days after Howard buys a scooter that looks like the one he had years ago.

E20The Decision Reverberation
Apr 25, 2019
Raj is worried people won’t take him seriously in his own field after publishing a paper that suggests he may have discovered alien life. Also, Leonard wants to be the principal investigator on a plasma physics study.

E21The Plagiarism Schism
May 2, 2019
Kripke has proof that Dr. Pemberton plagiarized his thesis in college, and Sheldon and Amy aren't sure if they should turn him in or not. Meanwhile, Howard learns that Bernadette wasn't the only waitress at the Cheesecake Factory who had a crush on him.

E22The Maternal Conclusion
May 9, 2019
Leonard is pleasantly surprised when Beverly comes to visit and she's genuinely kind to him, until he finds out the real reason she's there. Also, Denise and Stuart overstay their welcome at the Wolowitz house.

E23The Change Constant / The Stockholm Syndrome
May 16, 2019
Sheldon and Amy await big news. Meanwhile, Penny and Leonard have some big news of their own. Also, Howard and Bernadette face the stressful challenge of leaving their kids for the first time and Raj makes a new friend, as the gang travels together into an uncharted future.

E24Unraveling the Mystery: A Big Bang Farewell
May 16, 2019
Johnny Galecki and Kaley Cuoco will lead fans on a trip down memory lane, sharing some of the best-kept backstage secrets and personal memories from the past 12 years.
Videos
Storyline
Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.























