Watch The Big Bang Theory

Leonard, Sheldon, Raj, and Howard aren't your average Pasadena post-grads. They are, each in his own right, geniuses, which makes for an interesting storm of nerdy antics and comical conundrums. Socially awkward, romantically-challenged, and professionally driven, the four stars play out more like brainy boys.

Thursday 8:00 pm et/pt on CBS
11 Seasons, 246 Episodes
September 24, 2007
Cast: Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg
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The Big Bang Theory Full Episode Guide

  • When Sheldon petitions Wil Wheaton to appear on the new Professor Proton show, Wil offers a role to Amy instead. Also, Penny gets angry when she thinks the female protagonist in Leonard's novel is based on her.

  • Koothrappali finds himself in the middle of domestic drama when he learns the woman he's dating, Nell, has a very upset husband, Oliver. Also, when Sheldon rents his old room back for a quiet place to work, he drives Leonard crazy by being a model tenant.

  • 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.

  • To discover who would be most qualified to be best man and maid of honor at their wedding, Sheldon and Amy subject their friends to a series of secret experiments. Also, Penny reveals her true feelings about Amy.

  • Sheldon and Wolowitz plan birthday celebrations for Amy and Halley, respectively. Also, Leonard receives a Christmas letter from his brother that causes him to spiral out about his own lack of accomplishments.

  • Sheldon and Amy try to eliminate stress from wedding planning by applying math to the process. Also, Koothrappali "breaks up" with Wolowitz after realizing his best friend is actually hurting his confidence.

  • 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.

  • Leonard and Wolowitz 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 Ruchi is trying to steal her job.

  • Sheldon and Bert collaborate on a research project, despite Sheldon's embarrassment. Also, Penny and Bernadette coach Koothrappali on how to navigate his relationship with Ruchi.

  • 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 Wolowitz both wind up on bed rest.

  • Sheldon and Koothrappali confide in Bernadette when they can't handle Amy and Wolowitz working together. Also, Penny and Leonard learn new tactics for how to deal Sheldon from an unlikely source.

  • Howard and Sheldon bond when they drive to the desert to shoot off a model rocket. Also, when Leonard's mom, Beverly, finds a new best friend in Penny, it rubs Leonard the wrong way.

  • As Sheldon stresses about picking a wedding date, Amy tries to convince him he has a more laid-back side. Also, Koothrappali and Stuart compete to win the heart of Bernadette's new coworker, Ruchi.

  • 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.

  • Amy gives Sheldon an answer to his proposal while Howard and Bernadette struggle with some unexpected news.

  • The gang is concerned when Sheldon's former admirer, Dr. Ramona Nowitzki, resurfaces while Amy is away at Princeton.

  • 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.

  • Leonard is upset when Penny considers taking a new job offered by her ex-boyfriend, Zack.

  • Howard and Bernadette struggle leaving Halley in day care when Bernadette's maternity leave is up. Also, Bert introduces the gang to his new girlfriend, Rebecca.

  • Sheldon spreads himself too thin when he works 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.

  • Leonard, Penny and Raj adjust to their new living situation and Sheldon becomes intrigued by Amy's work.

  • When the gang offers a place for Raj to live, it creates unexpected conflict among everyone and an argument between Amy and Leonard's mother.

  • Sheldon and Amy have their first fight since moving in together and Koothrappali is stunned by what financial independence really means when he stops receiving support from his father.

  • 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.

  • Sheldon uses a machine to help him identify other people's emotions, and Raj tries to make sense of why he struggles with women.

  • Sheldon gets involved when Leonard and Penny get into an argument. Meanwhile, Howard and Raj are determined to fix a squeaky floorboard in the baby's room.

  • Sheldon and Amy see Leonard and Penny for the first time since the holidays and share the details of their trip to Texas.

  • Amy's birthday wish is to have an intimate night with Sheldon, but things are interrupted when Bernadette goes into labor.

  • Sheldon and Leonard must separate their stuff and remove Penny's things from 4B.

  • Sheldon is green with envy when Bert, a Caltech geologist, wins the MacArthur Genius fellowship. Also, Wolowitz finds an old remote control Stephen Hawking action figure he invented.

  • Following a successful experiment combining their genes, Sheldon is determined to convince Amy they should procreate. Also, Koothrappali is ashamed to tell the gang the occupation of his new girl.

  • Amy lies to Sheldon so she can still live with him. Later, they host an "on location" episode of "Fun With Flags" in Penny’s apartment.

  • Penny is pleasantly surprised when she discovers she has fans of her performance in "Serial Ape-ist." Also, Amy hosts a Sheldon-style brunch at Penny's apartment, and Wolowitz gets spontaneous.

  • 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.

  • Sheldon can't keep up with the late nights Howard and Leonard are putting in, Raj spends the day with a pregnant Bernadette and Penny and Amy attend a faculty party.

  • The Air Force shows interest in the guidance system and Penny lets it slip at work that Bernadette is expecting.

  • A night of revelry and bad decisions on behalf of the guys' parents results in an awkward morning. Penny's dysfunctional family is in town as well; chaos ensues.

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The Big Bang Theory Video Clips & Extras

The Neonatal Nomenclature (Preview) Clip (00:21) The Neonatal Nomenclature (Sneak Peek) Clip (00:28) Leonard Figures It Out Clip (01:39)