E1 - The Electric Can Opener Fluctuation

Aired: September 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.

E2 - The Jiminy Conjecture

Aired: September 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.

E3 - The Gothowitz Deviation

Aired: October 05, 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.

E4 - The Pirate Solution

Aired: October 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.

E5 - The Creepy Candy Coating Corollary

Aired: October 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.

E6 - The Cornhusker Vortex

Aired: November 02, 2009

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

E7 - The Guitarist Amplification

Aired: November 09, 2009

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

E8 - The Adhesive Duck Deficiency

Aired: November 16, 2009

With Leonard, Howard and Raj away camping in the desert, an injured Penny has only Sheldon to rely on.

E9 - The Vengeance Formulation

Aired: November 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.

E10 - The Gorilla Experiment

Aired: December 07, 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.

E11 - The Maternal Congruence

Aired: December 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.

E12 - The Psychic Vortex

Aired: January 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.

E13 - The Bozeman Reaction

Aired: January 18, 2010

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

E14 - The Einstein Approximation

Aired: February 01, 2010

Sheldon's search for the answer to a physics problem leads him to work at the Cheesecake Factory with Penny.

E15 - The Large Hadron Collision

Aired: February 08, 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.

E16 - The Excelsior Acquisition

Aired: March 01, 2010

Sheldon winds up in traffic court when he gets a ticket because of Penny.

E17 - The Precious Fragmentation

Aired: March 08, 2010

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

E18 - The Pants Alternative

Aired: March 22, 2010

Sheldon's friends come to his aid when his fear of public speaking stands between him and a coveted award.

E19 - The Wheaton Recurrence

Aired: April 12, 2010

A fight between Leonard and Penny threatens their relationship, while Sheldon battles Wil Wheaton in bowling.

E20 - The Spaghetti Catalyst

Aired: May 03, 2010

When Leonard and Penny aren't speaking, Sheldon goes to extremes to keep them both happy.

E21 - The Plimpton Stimulation

Aired: May 10, 2010

Leonard and Sheldon compete for the attention of a famous female physicist.

E22 - The Staircase Implementation

Aired: May 17, 2010

Leonard tells Penny about how he met Sheldon for the first time...and what happened to the elevator.

E23 - The Lunar Excitation

Aired: 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.