The Big Bang Theory
About the Show
Arch-nerds Leonard and Sheldon may know more than their fair share about subatomic particles, but when it comes to people in general, and women in particular, they're absolutely clueless...
Series 4 Summary
In this series Sheldon goes on his first ever date, Wolowitz finds a new use for a robotic arm, the gang meet Apple co-founder Steve Wozniak and Sheldon calculates how many relationships Penny has had.
Episode 1 - The Robotic Manipulation
In the opening episode, Penny tags along to Sheldon's first ever date with a woman he's been texting for months.
Meanwhile, Wolowitz finds a new use for a robotic arm.
Episode 2 - The Cruciferous Vegetable Amplification
When Sheldon realises that he won't live long enough to download his consciousness into a robot body, he attempts to extend his lifespan.
Meanwhile, the gang bump into Apple co-founder Steve Wozniak (played by himself) at The Cheesecake Factory.
Episode 3 - The Zazzy Substitution
The guys are concerned when Sheldon searches for an alternative to human companionship after he and Amy break up. Can they help restore his faith in people?
When things take a turn for the worse and Sheldon bulk buys pet cats, Leonard gets Sheldon's mum to pay him a visit.
Episode 4 - The Hot Troll Deviation
An embarrassing secret of Wolowitz's comes to light as he tries to win back his ex-girlfriend, Bernadette.
Meanwhile, Sheldon and Raj engage in a battle of wills.
Episode 5 - The Desperation Emanation
Leonard realises that he's the only one of the gang without a girlfriend, while Sheldon wants to get rid of his when she hatches a plan for him to meet her mother.
Episode 6 - The Irish Pub Formulation
A visit from Raj's sister Priya creates tension among the guys - especially when Leonard coaxes Sheldon into hiding his romantic past with Priya from the rest of the gang.
Episode 7 - The Apology Insufficiency
Leonard believes his problem with women stems from a lack of confidence, and vows to be more self-assured around attractive women.
Meanwhile, Wolowitz has a call from the FBI.
Episode 8 - The 21-Second Excitation
The group are excited about a new screening of Indiana Jones and Raiders of the Lost Ark because there are 21 seconds of additional footage being seen for the first time, and camp out to get tickets for the film.
But their plans are scuppered by Sheldon's nemesis, Wil Wheaton (guest starring as himself).
Closer to home, Penny and Bernadette invite Amy to her first slumber party.
Episode 9 - The Boyfriend Complexity
When Penny's dad comes to visit, Leonard discovers that she told her parents they were back together, because they always had a soft spot for him.
Leonard takes full advantage and plays his boyfriend role to the hilt, much to Penny's dismay.
Raj is disappointed when Bernadette shows up during his and Howard's quality time, but they end up bonding more than Howard would like,
Episode 10 - The Alien Parasite Hypothesis
Amy discovers that she has feelings for Penny's ex-boyfriend Zack.
Meanwhile, Koothrappali and Wolowitz try to prove who would be the better superhero.
Episode 11 - The Justice League Recombination
The guys warm to Penny's new boyfriend Zack and find a way to bond with him.
Episode 12 - The Bus Pants Utilization
Leonard's idea for a smartphone application derails his friendship with Sheldon and they fight for control of the project.
Please note that the second half of this series is due to be shown in summer 2011.
Episode 13 - The Love Car Displacement
Tensions run high when Bernadette runs into her hulk of an ex-boyfriend at a science conference.
Threatened by her ex, Wolowitz has an argument with Bernadette and causes chaos with the hotel room arrangements.
Episode 14 - The Thespian Catalyst
Sheldon agrees to take part in a short lecture series at the university, but is unnerved by the students' apparent dislike of him.
On Amy's advice, he asks Penny to give him acting lessons so he can learn to engage his audience better. Koothrappali, meanwhile, fantasises about his best friend's girlfriend.
Episode 15 - The Benefactor Factor
A wealthy benefactor at the university makes Leonard ponder just how far he's willing to go in the name of science.
Episode 16 - The Cohabitation Formulation
Wolowitz is torn between taking things to the next level with Bernadette, and pleasing his mother.
Leonard rekindles his relationship with Raj's sister, Priya.
Episode 17 - The Toast Derivation
Sheldon gets a new group of friends when the gang start hanging out at Raj's more often and he realises that it's actually Leonard who is the centre of their social group and not him.
Episode 18 - The Prestidigitation Approximation
Leonard must choose between his new girlfriend Priya, and his friendship with Penny. Meanwhile, Howard drives Sheldon crazy with a magic trick.
Episode 19 - The Zarnecki Incursion
When someone hacks Sheldon's online gaming account, the guys go on a quest to find the culprit.
Episode 20 - The Herb Garden Germination
Sheldon and Amy experiment on their friends by spreading gossip, while Howard takes a big step in his relationship with Bernadette.
Episode 21 - The Agreement Dissection
Priya uses her legal nous to dissect the roommate agreement and put Sheldon in his place. Meanwhile, the girls take Sheldon dancing.
Episode 22 - The Wildebeest Implementation
Raj attempts to cure his social anxiety disorder around talking to women, while Penny uses Bernadette to spy on Leonard and his girlfriend.
Episode 23 - The Engagement Reaction
Howard finally tells him mum that he's engaged to Bernadette. Unfortunately, the news lands his mum in hospital.
Episode 24 - The Roomate Transmogrification
Bernadette receives her PhD; time for the gang to tease Wolowitz for being the only one among them who isn't a doctor.
Meanwhile, Koothrappali becomes Sheldon's new flatmate after hearing Leonard and Priya engaging in a Star Trek bedroom fantasy.
The Big Bang Theory synopsis
Arch-nerds Leonard and Sheldon may know more than their fair share about subatomic particles, but when it comes to people in general, and women in particular, they're absolutely clueless...Episode Guide >
Next on TV
The guys take a road trip to a comic book convention in Bakersfield and visit a location where several episodes of Star Trek were filmed.