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Season 1
Episodes – 17
Preview
S01E01
Pilot
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.
Air Date September 24, 2007
S01E02
The Big Bran Hypothesis
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.
Air Date October 1, 2007
S01E03
The Fuzzy Boots Corollary
Leonard asks a woman out after he finds out that Penny is seeing someone.
Air Date October 8, 2007
S01E04
The Luminous Fish Effect
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.
Air Date October 14, 2007
S01E05
The Hamburger Postulate
Fearing he's wasting his time on Penny, Leonard ends up making a connection with Leslie.
Air Date October 22, 2007
S01E06
The Middle Earth Paradigm
Penny hosts a Hallowe'en party, putting Leonard, Sheldon, Wolowitz, and Koothrappali through a new test of their social skills.
Air Date October 29, 2007
S01E07
The Dumpling Paradox
With Wolowitz AWOL with one of her friends, Penny's recruited to fill in for him on the guys' Halo team
Air Date November 5, 2007
S01E08
The Grasshopper Experiment
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.
Air Date November 12, 2007
S01E09
The Cooper-Hofstadter Polarization
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.
Air Date March 17, 2008
S01E10
The Loobenfeld Decay
Leonard and Sheldon each lie to avoid seeing Penny's concert, but Sheldon's is a bit too complicated for his own good.
Air Date March 24, 2008
S01E11
The Pancake Batter Anomaly
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.
Air Date March 31, 2008
S01E12
The Jerusalem Duality
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.
Air Date April 14, 2008
S01E13
The Bat Jar Conjecture
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.
Air Date April 21, 2008
S01E14
The Nerdvana Annihilation
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.
Air Date April 28, 2008
S01E15
The Pork Chop Indeterminacy
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.
Air Date May 5, 2008
S01E16
The Peanut Reaction
Penny wants to throw a surprise party for Leonard, but Sheldon's indulgence at an electronics store throws her off-track.
Air Date May 12, 2008
S01E17
The Tangerine Factor
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.
Air Date May 19, 2008