The Big Bang Theory ( season 3 ) - wikipedia The Big Bang Theory ( season 3 ) The Big Bang Theory ( season 3 ) Third season DVD cover art Starring Johnny Galecki Jim Parsons Kaley Cuoco Simon Helberg Kunal Nayyar Country of origin United States No. of episodes 23 Release Original network CBS Original release September 21, 2009 ( 2009 - 09 - 21 ) -- May 24, 2010 ( 2010 - 05 - 24 ) Season chronology ← Previous Season 2 Next → Season 4 List of The Big Bang Theory episodes The third season of the American sitcom The Big Bang Theory was originally aired on CBS from September 21, 2009 to May 24, 2010 with 23 episodes. It received higher ratings than the previous two seasons with over 15 million viewers. Season three started three months after the end of season two when the guys left for the North Pole. The third season saw the first appearances of future main cast members Melissa Rauch as Bernadette Rostenkowski in `` The Creepy Candy Coating Corollary '' and Mayim Bialik as Dr. Amy Farrah Fowler in the season finale `` The Lunar Excitation ''. Christine Baranski submitted the episode `` The Maternal Congruence '' for consideration due to her nomination for the Primetime Emmy Award for Outstanding Guest Actress in a Comedy Series at the 62nd Primetime Emmy Awards. Jim Parsons won the Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series at the 62nd Primetime Emmy Awards for the episode `` The Pants Alternative ''. Contents 1 Overview 2 Cast 2.1 Main cast 2.2 Special guest cast 2.3 Recurring cast 2.4 Guest cast 3 Episodes 4 Ratings 5 Reception 6 References 7 External links Overview Penny throws herself at Leonard after he returns from three months at the North Pole, and they begin a relationship that lasts most of the season. Penny and Sheldon start a quirky friendship ( though she can still annoy him ). Wil Wheaton begins appearing as Sheldon 's arch - enemy. Howard begins to date Bernadette Rostenkowski. At the end of the season, Sheldon meets Amy Farrah Fowler. Cast Main article : List of The Big Bang Theory characters Main cast Johnny Galecki as Leonard Hofstadter Jim Parsons as Sheldon Cooper Kaley Cuoco as Penny Simon Helberg as Howard Wolowitz Kunal Nayyar as Rajesh `` Raj '' Koothrappali Special guest cast Katee Sackhoff as herself Ira Flatow as himself Stan Lee as himself Recurring cast Laurie Metcalf as Mary Cooper Carol Ann Susi as Mrs. Wolowitz John Ross Bowie as Dr. Barry Kripke Wil Wheaton as Himself Kevin Sussman as Stuart Bloom Melissa Rauch as Bernadette Rostenkowski Brian George as Dr. V.M. Koothrappali Alice Amter as Mrs. Koothrappali Christine Baranski as Dr. Beverly Hofstadter Sara Gilbert as Leslie Winkle Brian Thomas Smith as Zack Johnson Guest cast Lewis Black as Professor Crawley Molly Morgan as Bethany Sarah Buehler as Sarah Andy Mackenzie as Skeeter Elizabeth Bogush as Dr. Catherine Millstone Oliver Muirhead as Professor Laughlin Zachary Abel as Todd Jason Mesches as Denny Danica McKellar as Abby Jen Drohan as Martha Julio Oscar Mechoso as Officer Hackett Yeardley Smith as Sandy Kevin Brief as Glenn Steve Paymer as Judge Kirby Marcus Folmar as Guard Frank Maharajh as Venkatesh Koothrappali Judy Greer as Dr. Elizabeth Plimpton Ally Maki as Joyce Kim Steven Yeun as Sebastian Ajgie Kirkland as Louie / Louise Lauri Johnson as Mrs. Gunderson Mayim Bialik as Dr. Amy Farrah Fowler Episodes See also : List of The Big Bang Theory episodes No. overall No. in season Title Directed by Written by Original air date Prod. code U.S. viewers ( millions ) 41 `` The Electric Can Opener Fluctuation '' Mark Cendrowski Steven Molaro September 21, 2009 ( 2009 - 09 - 21 ) 3X5551 12.96 When the men return home from their expedition at the Magnetic North Pole, Penny reveals her feelings for Leonard and kisses him when he visits her. Both are interrupted when Sheldon is humiliated on learning that Leonard, Howard and Raj tampered with one of his experiments, and retreats to his mother 's home in Galveston, Texas. When Leonard arrives in Texas, it is Mary who convinces Sheldon to forgive him by disagreeing with his views on evolution. Leonard and Penny then finally have sex, but concede that things are now weird between them. Title reference : The electric can opener used by the men to fake the results of Sheldon 's experiment while at the Magnetic North Pole. 42 `` The Jiminy Conjecture '' Mark Cendrowski Jim Reynolds September 28, 2009 ( 2009 - 09 - 28 ) 3X5552 13.27 Leonard and Penny vacillate between friendship and a romantic relationship, struggling to resolve the awkwardness. In an attempt to feel comfortable and talk about a solution, they end up getting drunk in her apartment and throwing up all night. Sheldon and Howard stake their most valuable comic books on a bet over the species of a cricket they hear, enlisting a depressed entomologist to settle the bet. After Sheldon loses the bet, he meets Penny and after talking to her about Leonard, assures her that she and Leonard can always go back to being friends. After she explains this to Leonard, the two agree to do so, but they find that neither wants to and have sex again. Title reference : Sheldon tries to guess the species of a cricket he names after Jiminy Cricket. 43 `` The Gothowitz Deviation '' Mark Cendrowski Story by : Lee Aronsohn & Richard Rosenstock Teleplay by : Bill Prady & Maria Ferrari October 5, 2009 ( 2009 - 10 - 05 ) 3X5553 12.52 Penny 's bed in her apartment breaks, forcing her to sleep at Leonard and Sheldon 's apartment for a few days. Sheldon tries to condition Penny, rewarding with chocolate what he considers to be `` correct '' behavior. Howard and Raj pretend to be goths to try to meet girls at a goth club, but chicken out when the girls persuade them to get tattoos. Title reference : Howard and Raj go to a Goth club. 44 `` The Pirate Solution '' Mark Cendrowski Steve Holland October 12, 2009 ( 2009 - 10 - 12 ) 3X5554 13.07 Raj 's research on trans - Neptunian objects comes to a dead end and he faces deportation to India unless he gets a new job. Sheldon offers Raj a chance to work for him. Raj accepts but disagreements ensue. Eventually, Sheldon apologises to Raj, conceding that his theory is correct but refusing to give up on his own. Howard tries to hang out with Leonard and Penny, but intrudes into their relationship. Title reference : Sheldon 's comment about Raj either emigrating to another country, returning to India, or `` wandering the high seas as a stateless pirate. '' 45 5 `` The Creepy Candy Coating Corollary '' Mark Cendrowski Story by : Chuck Lorre & Bill Prady Teleplay by : Lee Aronsohn & Steven Molaro October 19, 2009 ( 2009 - 10 - 19 ) 3X5556 13.47 Howard reminds Leonard of their girlfriend pact : one of the two men ( Leonard ) who has a girlfriend ( Penny ) must have her set the other man ( Howard ) up on a date with her friend. After prodding by Leonard, a reluctant Penny sets Howard with her friend Bernadette, though they find they have little in common. However, the two bond over their respective relationships with their mothers. Sheldon enters a collectible card game tournament, with Raj as his partner, to compete against his rival Wil Wheaton. Note : This episode marks the first appearance of future regular cast member Melissa Rauch as Bernadette Rostenkowski and also marks the first cameo appearance of Wil Wheaton on the show. Title reference : Penny 's description of Howard 's outward behavior. Also Howard losing his virginity in a Corolla. 46 6 `` The Cornhusker Vortex '' Mark Cendrowski Story by : Bill Prady & Steven Molaro Teleplay by : Dave Goetsch & Richard Rosenstock November 2, 2009 ( 2009 - 11 - 02 ) 3X5555 12.73 Leonard attempts to fit in with Penny 's football - loving friends, despite initially knowing nothing about the game. However, it is Sheldon who surprises him with a large amount of football knowledge ( forced on him by his father in his childhood ), which Leonard later brings to Penny 's football party. When Leonard refuses to fly kites with Sheldon, upsetting him as he never got to experience a normal childhood, Penny feels bad and allows Leonard to go, especially after pointing out how he is boring everyone at the party. Howard upsets Raj by repeatedly abandoning him during activities to pursue women. Title reference : The football team Penny and her friends watch. 47 7 `` The Guitarist Amplification '' Mark Cendrowski Story by : Chuck Lorre & Lee Aronsohn Teleplay by : Bill Prady & Richard Rosenstock & Jim Reynolds November 9, 2009 ( 2009 - 11 - 09 ) 3X5557 12.79 When Penny announces that her guitarist friend, who she dated twice, is going to sleep on her couch for the next few days, Leonard is upset that she did n't ask him first. Sheldon is upset by reminders of his quarrelling parents as Leonard and Penny fight, Raj argues with his parents and Howard argues with his mother. Title reference : Penny 's guitarist friend. 48 8 `` The Adhesive Duck Deficiency '' Mark Cendrowski Story by : Chuck Lorre & Bill Prady & Dave Goetsch Teleplay by : Steven Molaro & Eric Kaplan & Maria Ferrari November 16, 2009 ( 2009 - 11 - 16 ) 3X5558 13.23 Sheldon, despite never having driven a car before, is forced to drive Penny to the hospital after she slips in the shower. Leonard, Raj and Howard go on a camping trip to watch the Leonid meteor shower, but all succumb to the effects of `` magic '' cookies given to them by Deadhead campers nearby, causing them to blurt out weird secrets including Howard losing his virginity to his second cousin. Title reference : Sheldon telling Penny that he has sticky non-slip duck shaped appliqués in his bath tub and that they would have prevented Penny 's accident. 49 9 `` The Vengeance Formulation '' Mark Cendrowski Story by : Chuck Lorre & Maria Ferrari Teleplay by : Richard Rosenstock & Jim Reynolds & Steve Holland November 23, 2009 ( 2009 - 11 - 23 ) 3X5559 14.13 After three successful dates, Howard reflects on the future of his relationship with Bernadette. He surprises her with a last - minute proposal, which she declines as it is much too soon for either of them. However, he wins her over by performing a cheesy love song, which she finds as romantic. A prank fight between Sheldon and Kripke begins when the latter severely embarrasses the former on National Public Radio 's talk show Science Friday by filling Sheldon 's office with helium, giving him a high - pitched voice. Title reference : Sheldon 's revenge against Kripke. 50 10 `` The Gorilla Experiment '' Mark Cendrowski Story by : Chuck Lorre & Richard Rosenstock & Steve Holland Teleplay by : Bill Prady & Steven Molaro & Maria Ferrari December 7, 2009 ( 2009 - 12 - 07 ) 3X5560 14.38 Howard becomes jealous of Leonard after Bernadette shows an interest in his work, causing friction in the relationship of all three. Penny becomes jealous over not being able to talk to Leonard about his job, and asks Sheldon to teach her about physics. Title reference : Sheldon 's view that teaching physics to Penny is equivalent in challenge to teaching sign language to Koko the gorilla. 51 11 `` The Maternal Congruence '' Mark Cendrowski Story by : Lee Aronsohn & Steven Molaro & Richard Rosenstock & Maria Ferrari Teleplay by : Chuck Lorre & Bill Prady & Dave Goetsch December 14, 2009 ( 2009 - 12 - 14 ) 3X5562 15.58 At Christmas, Leonard 's mother visits, much to Leonard 's horror and Sheldon 's delight. Penny is upset to learn that Leonard has not told her about his mother 's visit, nor his mother about their relationship, while Leonard learns that Sheldon appears to know more about his parents ' lives than he does. Title reference : Leonard 's mother visiting him again. 52 12 `` The Psychic Vortex '' Mark Cendrowski Story by : Lee Aronsohn & Steven Molaro Teleplay by : Chuck Lorre & Eric Kaplan & Jim Reynolds January 11, 2010 ( 2010 - 01 - 11 ) 3X5561 15.82 Penny is upset when Leonard derides her for taking advice from a psychic. Awkward situations ensue as Sheldon and Raj date two women they met at a university mixer, Raj having bribed Sheldon to be his wingman. Title reference : Penny 's belief in psychics. 53 13 `` The Bozeman Reaction '' Mark Cendrowski Story by : Bill Prady & Lee Aronsohn & Jim Reynolds Teleplay by : Chuck Lorre & Steven Molaro & Steve Holland January 18, 2010 ( 2010 - 01 - 18 ) 3X5563 14.99 Sheldon fears for his safety after his and Leonard 's apartment is burgled, and takes various measures to try to increase his security. Title reference : Sheldon moves to Bozeman, Montana after his and Leonard 's apartment is robbed. 54 14 `` The Einstein Approximation '' Mark Cendrowski Story by : Lee Aronsohn & Dave Goetsch & Steve Holland Teleplay by : Chuck Lorre & Steven Molaro & Eric Kaplan February 1, 2010 ( 2010 - 02 - 01 ) 3X5565 15.51 After becoming obsessed with a physics problem, Sheldon decides to take a menial job, comparing himself to Albert Einstein, who conceived his theory of relativity while working at the Swiss patent office. Meanwhile, Raj feels left out when Leonard, Penny, Howard and Bernadette go on a double - date at a roller skating rink. Title reference : Sheldon 's attempt at solving his problem by working in a menial job, comparing it to Albert Einstein 's discoveries made while working in Switzerland in the Patent Office. 55 15 `` The Large Hadron Collision '' Mark Cendrowski Story by : Chuck Lorre & Steven Molaro & Jim Reynolds Teleplay by : Lee Aronsohn & Richard Rosenstock & Maria Ferrari February 8, 2010 ( 2010 - 02 - 08 ) 3X5564 16.26 Sheldon feels betrayed when Leonard decides to take Penny, not Sheldon, with him to a conference in Switzerland, where they will also have the chance to visit the Large Hadron Collider. After failing to convince Leonard to change his mind, Sheldon tries to convince Penny to drop out, which leads Leonard to terminate his friendship with Sheldon. However, when Penny has caught the flu, Leonard changes his mind and allows Sheldon to go, only to find out he is sick as well, causing him to take Raj. It is later revealed that Sheldon caught it from Penny when he hugged her. Title reference : The dispute between Leonard and Sheldon over who gets to be Leonard 's guest for the trip to the Large Hadron Collider. 56 16 `` The Excelsior Acquisition '' Peter Chakos Story by : Chuck Lorre & Lee Aronsohn & Steven Molaro Teleplay by : Bill Prady & Steve Holland & Maria Ferrari March 1, 2010 ( 2010 - 03 - 01 ) 3X5566 15.73 Sheldon tries to meet Stan Lee at a comic book signing, but is stymied by having to appear in court for running a red light while taking Penny to the hospital, and enlists Penny to help him win the judge 's favor. Title reference : Stan Lee 's comic book signing event. 57 17 `` The Precious Fragmentation '' Mark Cendrowski Story by : Lee Aronsohn & Eric Kaplan & Maria Ferrari Teleplay by : Bill Prady & Steven Molaro & Richard Rosenstock March 8, 2010 ( 2010 - 03 - 08 ) 3X5567 16.32 Sheldon, Raj, Leonard and Howard acquire a collectible casting of the One Ring, which turns out to be a prop from The Lord of the Rings film trilogy. Fights and deceptions ensue as the four try various means to prevent the others from possessing it, as Penny observes in disbelief. Title reference : The guys ' fight over the One Ring. 58 18 `` The Pants Alternative '' Mark Cendrowski Story by : Chuck Lorre & Bill Prady & Steve Holland Teleplay by : Eric Kaplan & Richard Rosenstock & Jim Reynolds March 22, 2010 ( 2010 - 03 - 22 ) 3X5568 13.42 The characters try to help Sheldon overcome his fear of public speaking in time for him to accept a science award. He is still nervous until Penny gets him drunk, causing him to spiral on a meltdown on stage which quickly goes viral. Title reference : Sheldon takes off his pants during his acceptance speech for the award whilst drunk. 59 19 `` The Wheaton Recurrence '' Mark Cendrowski Story by : Chuck Lorre & Steven Molaro & Nicole Lorre & Jessica Ambrosetti Teleplay by : Bill Prady & Dave Goetsch & Jim Reynolds & Maria Ferrari April 12, 2010 ( 2010 - 04 - 12 ) 3X5569 13.39 Leonard and Penny reflect on their relationship after Penny does not reciprocate when Leonard tells her he loves her. At a bowling match with Stuart and others, including Sheldon 's rival Wil Wheaton, the two question their future together, but Wheaton may also be interfering. Title reference : Wil Wheaton 's return as a guest star on the show. 60 20 `` The Spaghetti Catalyst '' Anthony Rich Chuck Lorre & Bill Prady & Lee Aronsohn & Steven Molaro May 3, 2010 ( 2010 - 05 - 03 ) 3X5570 11.63 Sheldon tries to maintain his friendships with Leonard and Penny, now that they have broken up, as they consider whether they can still be friends with each other. Title reference : Sheldon 's spaghetti dinner with Penny and how it influences Penny and Leonard 's friendship. 61 21 `` The Plimpton Stimulation '' Mark Cendrowski Story by : Chuck Lorre & Bill Prady & Lee Aronsohn Teleplay by : Steven Molaro & Jim Reynolds & Maria Ferrari May 10, 2010 ( 2010 - 05 - 10 ) 3X5571 13.73 Dr. Elizabeth Plimpton, a cosmological physicist from Princeton University, accepts Sheldon 's invitation to stay over at the apartment during her visit to Caltech. However, she instead takes an immediate interest in Leonard, and the two end up sleeping together, inciting jealousy from Penny. However, it quickly becomes clear that Leonard and Elizabeth both have very different ideas about the nature of their relationship, when she sleeps with Raj and tries to convince Leonard and Howard ( who has just broken up with Bernadette ) to engage in a foursome with them. Title reference : Dr. Elizabeth Plimpton visits and `` stimulates '' Leonard and Raj. 62 22 `` The Staircase Implementation '' Mark Cendrowski Story by : Lee Aronsohn & Steven Molaro & Steve Holland Teleplay by : Chuck Lorre & Dave Goetsch & Maria Ferrari May 17, 2010 ( 2010 - 05 - 17 ) 3X5572 15.02 Taking shelter in Penny 's apartment after an argument with Sheldon, Leonard tells Penny how he and Sheldon met in 2003. He describes the trials he underwent in order to become Sheldon 's roommate, which reveal many aspects of the latter 's character, and in the process reveals how their building 's elevator came to be out of order. Title reference : Because Leonard 's rocket fuel explodes inside the elevator and destroys it, the stairway becomes indispensable. 63 23 `` The Lunar Excitation '' Peter Chakos Story by : Chuck Lorre & Bill Prady & Maria Ferrari Teleplay by : Lee Aronsohn & Steven Molaro & Steve Holland May 24, 2010 ( 2010 - 05 - 24 ) 3X5573 14.78 Penny introduces her new boyfriend Zack to the other characters as they set up an experiment to bounce a laser off the moon using the laser reflector left by Apollo 11, but grows disappointed with him as she watches him interact with the group. She later breaks up with him and drunken rants at Leonard for ruining her ability to tolerate idiots before proceeding to engage in sex with him, leading Leonard to hypothesize that he too can initiate drunken sex, which he tests throughout the episode. Meanwhile, Raj and Howard create a profile for Sheldon on a dating website without his knowledge, which to their surprise matches him with a woman named Amy Farrah Fowler. The two force Sheldon to meet Amy, and are surprised when Sheldon and Amy have a lot in common, ranging from sock aversion to their overbearing mothers. Title reference : The guys bouncing a laser off the reflector left on the moon by the crew of Apollo 11. Ratings No. Title Air date Rating / share ( 18 -- 49 ) Viewers ( millions ) `` The Electric Can Opener Fluctuation '' September 21, 2009 4.7 / 11 12.96 `` The Jiminy Conjecture '' September 28, 2009 5.3 / 13 13.27 `` The Gothowitz Deviation '' October 5, 2009 4.5 / 10 12.52 `` The Pirate Solution '' October 12, 2009 5.0 / 12 13.07 5 `` The Creepy Candy Coating Corollary '' October 19, 2009 5.3 / 13 13.47 6 `` The Cornhusker Vortex '' November 2, 2009 4.7 / 11 12.73 7 `` The Guitarist Amplification '' November 9, 2009 4.7 / 11 12.79 8 `` The Adhesive Duck Deficiency '' November 16, 2009 5.0 / 12 13.23 9 `` The Vengeance Formulation '' November 23, 2009 5.2 / 13 14.13 10 `` The Gorilla Experiment '' December 7, 2009 5.6 / 13 14.38 11 `` The Maternal Congruence '' December 14, 2009 5.6 / 14 15.58 12 `` The Psychic Vortex '' January 11, 2010 5.7 / 14 15.82 13 `` The Bozeman Reaction '' January 18, 2010 5.2 / 12 14.99 14 `` The Einstein Approximation '' February 1, 2010 5.4 / 13 15.51 15 `` The Large Hadron Collision '' February 8, 2010 6.0 / 14 16.26 16 `` The Excelsior Acquisition '' March 1, 2010 5.9 / 14 15.73 17 `` The Precious Fragmentation '' March 8, 2010 5.9 / 15 16.32 18 `` The Pants Alternative '' March 22, 2010 5.2 / 13 13.42 19 `` The Wheaton Recurrence '' April 12, 2010 5.1 / 13 13.39 20 `` The Spaghetti Catalyst '' May 3, 2010 4.6 / 12 11.63 21 `` The Plimpton Stimulation '' May 10, 2010 5.3 / 13 13.73 22 `` The Staircase Implementation '' May 17, 2010 5.5 / 14 15.02 23 `` The Lunar Excitation '' May 24, 2010 5.2 / 13 14.78 Reception The third season received favorable reviews. Maureen Ryan of Chicago Tribune wrote that `` Big Bang Theory, which is in its third season, is doing many things very right '', Alan Sepinwall of The Star - Ledger wrote `` the Penny / Sheldon interaction was gold, as always '', and Ken Tucker of Entertainment Weekly, who wrote that `` what lifts The Big Bang Theory into frequent excellence is its one constant from the start : the brilliantly nuanced performance of Jim Parsons ''. The American Film Institute ranked season three one of the ten best television seasons of 2009. References ^ Jump up to : `` Super Night for CBS 's Comedy Power Hour ''. CBS. February 9, 2010. Retrieved September 28, 2010. ^ Jump up to : Seidman, Robert ( September 22, 2009 ). `` Monday broadcast final numbers ''. TV by the Numbers. Archived from the original on October 5, 2009. Retrieved June 13, 2010. ^ Jump up to : Seidman, Robert ( September 29, 2009 ). `` Big Bang Theory 's BANG even louder in final numbers, rises to 5.3 w / adults 18 -- 49 ''. TV by the Numbers. Archived from the original on October 4, 2009. Retrieved June 13, 2010. ^ Jump up to : Seidman, Robert ( October 6, 2009 ). `` '' The Big Bang Theory '' builds on its lead - in for third straight week ``. TV by the Numbers. Archived from the original on October 9, 2009. Retrieved June 13, 2010. ^ Jump up to : `` CBS Wins Monday in Key Demos ''. CBS. October 13, 2009. Archived from the original on January 8, 2014. Retrieved January 5, 2013. ^ Jump up to : `` The Biggest Bang Yet ! ''. CBS. October 20, 2009. Archived from the original on January 8, 2014. Retrieved January 5, 2013. ^ Jump up to : `` '' How I Met Your Mother '' Delivers Largest Audience Since Its Season Premiere ``. CBS. November 3, 2009. Archived from the original on January 8, 2014. Retrieved January 5, 2013. ^ Jump up to : `` CBS First in Viewers for the Sixth Time in Seven Weeks ''. CBS. November 10, 2009. Archived from the original on January 8, 2014. Retrieved January 5, 2013. ^ Jump up to : `` CBS Places First on Monday in Adults 18 - 49 and Adults 25 - 54 ''. CBS. November 18, 2009. Archived from the original on May 31, 2012. Retrieved January 5, 2013. ^ Jump up to : `` Monday Comedies Lead CBS to Win in Key Demos ''. CBS. November 24, 2009. Archived from the original on January 8, 2014. Retrieved January 5, 2013. ^ Jump up to : Seidman, Robert ( December 8, 2009 ). `` Monday Finals : Big Bang Theory drops a tick ; Castle drops two ticks ''. TV by the Numbers. Archived from the original on December 11, 2009. Retrieved June 13, 2010. ^ Jump up to : `` Viewers embrace CBS Monday ''. CBS. December 15, 2009. Retrieved October 25, 2010. ^ Jump up to : Seidman, Robert ( January 12, 2010 ). `` Monday Broadcast Finals Plus Chuck Quarter Hour Detail ''. TV by the Numbers. Archived from the original on January 17, 2010. Retrieved June 13, 2010. ^ Jump up to : Seidman, Robert ( January 19, 2010 ). `` TV Ratings : CBS Wins ; How I Met Your Mother hits season highs ; Life Unexpected Premieres Solidly ''. TV by the Numbers. Archived from the original on June 11, 2010. Retrieved June 13, 2010. ^ Jump up to : `` CBS sweeps Monday in viewers and Key demographics ''. CBS. February 3, 2010. Retrieved October 5, 2010. ^ Jump up to : `` CBS 's Monday Comedy Block grows opposite `` The Bachelor '' final and Olympic - Promoted NBC ``. CBS. March 2, 2010. Retrieved October 25, 2010. ^ Jump up to : `` Editor 's Note : With final Monday ratings in, The Big Bang Theory has now reached a new series high in viewers ( 16.32 m ) and was the night 's top program in adults 18 - 49 ( 5.9 / 15 ), up a tenth from this morning. -- `` Two and a Half Men '' Soars to Its Best Adult 18 - 49 Rating in Three Years ``. CBS. March 9, 2010. Archived from the original on January 8, 2014. Retrieved January 5, 2013. ^ Jump up to : Seidman, Robert ( March 23, 2010 ). `` Monday Finals : `` Dancing With the Stars '' Rises ; `` Castle '' Falls ``. TV by the Numbers. Archived from the original on March 27, 2010. Retrieved June 13, 2010. ^ Jump up to : Gorman, Bill ( April 13, 2010 ). `` Monday Broadcast Finals : Dancing, 2.5 Men, Big Bang Adjusted Up ; Castle, CSI : Miami, 24 Adjusted Down ''. TV by the Numbers. Archived from the original on April 17, 2010. Retrieved June 13, 2010. ^ Jump up to : Seidman, Robert ( May 4, 2010 ). `` Monday Finals : '' House, '' `` Big Bang '' Adjusted Up ; `` Romantically Challenged, '' `` Castle '' Adjusted Down ``. TV by the Numbers. Archived from the original on May 7, 2010. Retrieved June 13, 2010. ^ Jump up to : `` '' The Big Bang Theory '' Makes Monday 's Loudest Noise in Adults 18 - 34, Adults 18 - 49 and Adults 25 - 54 ``. CBS. May 11, 2010. Archived from the original on September 23, 2015. Retrieved January 5, 2013. ^ Jump up to : `` This Just In... From CBS Entertainment... `` The Big Bang Theory '' Tops Monday in Key Demos ``. CBS. May 18, 2010. Archived from the original on January 2, 2014. Retrieved January 5, 2013. ^ Jump up to : `` CBS Wins the Final Monday of the Season in Key Demos ''. CBS. May 25, 2010. Archived from the original on January 2, 2014. Retrieved January 5, 2013. Jump up ^ Ryan, Maureen ( January 10, 2010 ). `` Having Big fun on a hit comedy : A chat with Big Bang Theory 's Johnny Galecki ''. Chicago Tribune. tronc. Archived from the original on September 12, 2016. Retrieved January 5, 2017. Jump up ^ Sepinwall, Alan ( December 8, 2009 ). `` Big Bang Theory, `` The Gorilla Experiment '' : Howard 's girlfriend Bernadette ``. The Star - Ledger. Advance Publications. Archived from the original on April 13, 2013. Retrieved January 5, 2017. Jump up ^ Tucker, Ken ( March 24, 2010 ). `` The Big Bang Theory ''. Entertainment Weekly. Time Inc. Archived from the original on January 6, 2017. Retrieved January 5, 2017. Jump up ^ `` AFI Awards 2009 ''. American Film Institute. Archived from the original on January 19, 2013. Retrieved January 5, 2017. General references `` The Big Bang Theory Season 3 episodes ''. TV Guide. Retrieved May 16, 2010. `` Shows A-Z -- big bang theory, the on CBS ''. the Futon Critic. Retrieved May 16, 2010. `` The Big Bang Theory : Episode Guide ''. MSN TV. Retrieved May 16, 2010. External links List of The Big Bang Theory episodes on IMDb The Big Bang Theory : Season 3 at Rotten Tomatoes The Big Bang Theory Characters Leonard Hofstadter Sheldon Cooper Penny Howard Wolowitz Raj Koothrappali Episodes Season 1 `` Pilot '' Season 2 `` The Terminator Decoupling '' Season 3 `` The Jiminy Conjecture '' Season 4 `` The Cruciferous Vegetable Amplification '' `` The Hot Troll Deviation '' `` The Love Car Displacement '' `` The Toast Derivation '' `` The Roommate Transmogrification '' Season 5 `` The Skank Reflex Analysis '' `` The Infestation Hypothesis '' `` The Wiggly Finger Catalyst '' `` The Russian Rocket Reaction '' `` The Rhinitis Revelation '' `` The Good Guy Fluctuation '' `` The Isolation Permutation '' `` The Flaming Spittoon Acquisition '' `` The Shiny Trinket Maneuver '' `` The Recombination Hypothesis '' `` The Beta Test Initiation '' `` The Werewolf Transformation '' `` The Hawking Excitation '' `` The Stag Convergence '' `` The Countdown Reflection '' Season 6 `` The Fish Guts Displacement '' `` The Santa Simulation '' `` The Egg Salad Equivalency '' Season 7 `` The Hofstadter Insufficiency '' `` The Convention Conundrum '' Season 8 `` The Locomotion Interruption '' Season 9 Season 10 Season 11 Recurring concepts `` Soft Kitty '' Related articles Awards and nominations Bazinga ( genus ) Euglossa bazinga Young Sheldon Portal Book Retrieved from `` https://en.wikipedia.org/w/index.php?title=The_Big_Bang_Theory_(season_3)&oldid=821102755 '' Categories : 2009 American television seasons 2010 American television seasons The Big Bang Theory seasons Hidden categories : Use mdy dates from September 2012 Talk Contents About Wikipedia Wikiquote Čeština Deutsch Español Français Italiano Português Română Русский Sicilianu 中文 Edit links This page was last edited on 18 January 2018, at 11 : 39. 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Question: when does amy come in big bang theory
Answer: The third season