The Big Bang Theory

3 seasons available

Physicists and best friends Leonard and Sheldon learn about the social aspects of life through their relationships with the free-spirited beauty who moves in next door.
The Cornhusker Vortex
S3 E6

Sheldon teaches Leonard how to understand football; a kite-fighting incident threatens Howard and Raj's friendship.

The Guitarist Amplification
S3 E7

Sheldon tries to make peace when Leonard and Penny get into an argument.

The Adhesive Duck Deficiency
S3 E8

Penny is forced to rely on Sheldon when she is injured while Howard, Leonard and Raj are away.

The Vengeance Formulation
S3 E9

After being humiliated on the radio, Sheldon vows to destroy Kripke; Wolowitz tries to not ruin his new relationship with Bernadette.

The Gorilla Experiment
S3 E10

Sheldon tries to help Penny understand Leonard's work; Wolowitz gets jealous when Leonard starts hanging out with his new girlfriend.

The Maternal Congruence
S3 E11

Leonard is horrified when his mother (Christine Baranski) visits.

The Psychic Vortex
S3 E12

Sheldon and Koothrappali attend a university mixer; Leonard discovers that Penny believes in psychics.

The Bozeman Reaction
S3 E13

After their apartment is robbed, Leonard and Sheldon turn to their friends to create a state-of-the-art security system.

The Einstein Approximation
S3 E14

Sheldon tries to figure out the answer to a physics problem by working with Penny.

The Large Hadron Collision
S3 E15

Leonard must choose who to bring with him when he goes to see the Large Hadron Collider on Valentine's Day.

The Excelsior Acquisition
S3 E16

Sheldon ends up in traffic court after getting a ticket because of Penny.

The Precious Fragmentation
S3 E17

When the guys buy a ring from "The Lord of the Rings" at a garage sale, the item threatens to tear them apart.

The Pants Alternative
S3 E18

Sheldon's stage fright stands between him and a coveted award.

The Wheaton Recurrence
S3 E19

Penny and Leonard have a fight that threatens their relationship; Sheldon and Wil Wheaton face off once again.

The Bad Fish Paradigm
S2 E1

Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.

The Codpiece Topology
S2 E2

After seeing Penny with a handsome new guy, Leonard rushes into a rebound relationship with Sheldon's nemesis, Leslie Winkle.

The Barbarian Sublimation
S2 E3

Sheldon creates a monster when he introduces Penny to online gaming.

Pilot
S1 E1

Leonard is happy to meet new neighbor Penny, but his roommate thinks he is chasing an impossible dream.

The Big Bran Hypothesis
S1 E2

Leonard volunteers to sign for a package, hoping to make a good impression on Penny.

The Fuzzy Boots Corollary
S1 E3

Unhappy to learn that Penny is seeing someone, Leonard summons the courage to ask another woman on a date.

The Luminous Fish Effect
S1 E4

Getting fired gives Sheldon the opportunity to explore life beyond physics, but when he spends his time weaving ponchos and acting like a shut-in, Leonard calls Sheldon's mother for assistance.

The Hamburger Postulate
S1 E5

Leonard, realizing his pursuit of Penny is fruitless, has an unexpected encounter with a fellow scientist (Sara Gilbert).

The Middle Earth Paradigm
S1 E6

Leonard, Sheldon, Wolowitz and Koothrappali attend Penny's Halloween party.

The Dumpling Paradox
S1 E7

Penny sleeps on Leonard and Sheldon's couch when Wolowitz seduces her friend and takes over her apartment; in need of a fourth member, the guys ask Penny to join their "Halo" team.

The Grasshopper Experiment
S1 E8

On a blind date, Koothrappali discovers that he can talk to the opposite sex after a few drinks, but his date takes an interest in Sheldon.

The Cooper-Hofstadter Polarization
S1 E9

Penny tries to mediate when Sheldon and Leonard disagree on whether to present their joint findings at a physics conference.

The Loobenfeld Decay
S1 E10

Leonard and Sheldon try to avoid seeing Penny perform after hearing her sing, but the elaborate lie Sheldon tells leads to an unexpected result.

The Pancake Batter Anomaly
S1 E11

Leonard and the boys avoid Sheldon when he gets sick, leaving Penny to nurse him back to health.

The Jerusalem Duality
S1 E12

Sheldon and Leonard look for a way to derail a 15-year-old physics prodigy's research.

The Bat Jar Conjecture
S1 E13

When Sheldon tries to prove his mental superiority as they train for the Physics Bowl, the guys kick him off the team and bring his nemesis (Sara Gilbert) aboard.

The Nerdvana Annihilation
S1 E14

Leonard and the guys buy a time machine prop from a classic movie; Penny tells the guys their obsession with comics and toys is pathetic.

The Pork Chop Indeterminacy
S1 E15

Leonard devises a plan to eliminate his rivals when he, Wolowitz and Koothrappali all fall for Sheldon's twin sister, but his plan backfires when Sheldon decides to choose who his sister dates.

The Peanut Reaction
S1 E16

Penny learns that Leonard does not celebrate birthdays, so she plans a surprise party; Sheldon unexpectedly gets to live out one of his biggest fantasies in an electronics store.

The Tangerine Factor
S1 E17

When Leonard finally works up the courage to ask Penny out on a date, they each turn to Sheldon for advice.