Forty-five days after leaving Pasadena to regroup after a series of unwanted changes in his life, Sheldon telephones Leonard to come pick him up in Kingman, Arizona, wher ...

Sheldon learns from Mrs. Davis in Human Resources that the university has come up with a solution to change his area of research from string theory to dark matter. They w ...

Although not their first choice, NASA asks Howard to throw the first pitch for a Los Angeles Angels game on Space Day. Non-athletic Howard is worried that he will make a ...

Emily joins the gang for the first time for one of their regular dinners at Leonard and Sheldon's apartment, she never yet having met either Leonard or Penny. As Emily is ...

Leonard, Sheldon, Howard and Raj all come to the conclusion that they have been so distracted ever since the arrival of the girls in their lives that they have not been a ...

As Sheldon's work is still relatively new in dark matter and as Raj hears about some ground breaking work in mines that may have major implications in both theoretical ph ...

Bernadette is excited to be asked to be included in a magazine photo shoot featuring the fifty sexiest female scientists. The topic places a wedge between her and Amy, wh ...

As Penny has her prom dress out after organizing her closet, she, Bernadette and Amy talk about their respective proms, the latter two whose were not what they would have ...

After Leonard tells Sheldon that he is having surgery to repair his deviated septum, Sheldon is convinced that Leonard will be the one in seven hundred thousand that will ...

Leonard, Howard and Raj are cleaning out the office of recently deceased Professor Roger Abbott. Rather than check through the material to save anything of worth as they ...

Raj can't host this year's Christmas Eve dinner party because his soon to be divorced father is coming for a visit. So Amy volunteers to host the dinner, she choosing the ...

Raj was part of a team which launched the New Horizon Space Probe nine years ago to collect data about Pluto, the probe which is now within distance to provide its first ...

Sheldon is having a mental block about his research into dark matter, and is wondering if he made a mistake changing his area of research. Based on a comment by Penny abo ...

Through a casual conversation with Penny, Leonard believes he's come up with a revolutionary scientific idea. Requiring some sort of validation, he asks Sheldon for his o ...

When the comic book store reopens, Howard is shocked to find his mothers futniture displayed. Meanwhile, after an incident with Amy, Sheldon is trying to let it go with P ...

Amy and Raj learn of a scientific experiment designed to see if it can make two people fall in love in the matter of hours. After the gang discusses the viability of the ...

Sheldon and Amy have decided to take their relationship to the next level... by purchasing a pet together, namely a turtle. That step takes a giant leap backward when She ...

After interviewing Sheldon, Scientific American writes a glowing article about Leonard and Sheldon's latest theory without mentioning Leonard by name, only referring to h ...

When Leonard and Sheldon are invited to speak at UC Berkeley, they take a detour to try and meet one of their idols. Meanwhile, while cleaning out Mrs. Wolowitz's house, ...

Wil Wheaton, Penny's co-star in Serial Apeist 2: Monkey See, Monkey Kill, invites her to be on his podcast to discuss the movie. Wil eventually asks Leonard, who is there ...

Raj is one of a select group of scientists who has been asked to submit a proposal for sending a message out into space on one of the Discovery missions, in the possibili ...

Leonard has been asked by those at his New Jersey high school to provide the commencement speech as this year's graduation ceremony. He plans to take Penny along with him ...

Both Leonard and Sheldon's mothers are coming to town to see them win an award for their joint research. The two diametrically opposed in viewpoint mothers have never met ...

Although on the surface it looks as if Sheldon and Amy's relationship is moving forward, an action by Sheldon demonstrates to Amy that she is still low on his list of pri ...