List of The Big Bang Theory Characters - Notable Guest Stars Appearing As Themselves

Notable Guest Stars Appearing As Themselves

Summer Glau (Season 2, "The Terminator Decoupling"): When the guys travel by train to a conference in San Francisco, they realize Summer Glau (who was in two science fiction television shows, Firefly and Terminator: The Sarah Connor Chronicles) is sitting in the same passenger car. Raj, Howard, and Leonard take turns talking with her. Raj cannot talk without drinking beer (which turned out to be non-alcoholic), Howard is his usual creepy, over-the-top self, and Leonard cannot start a conversation before she has to get off the train.

Wil Wheaton first appeared in the season 3 episode "The Creepy Candy Coating Corollary". See his entry in the recurring character section for more information.

Katee Sackhoff (Season 3, "The Vengeance Formulation" and Season 4, "The Hot Troll Deviation"): Howard fantasizes about taking a bath with Katee Sackhoff (Captain Kara "Starbuck" Thrace in Battlestar Galactica). However, in his own fantasy Sackhoff scolds him and tells him to get a real girlfriend instead of imaginary ones. Sackhoff reappeared in a different fantasy of Howard's in The Hot Troll Deviation, where she and George Takei help Howard realize that he still has feelings for Bernadette.

George Takei (Season 4, "The Hot Troll Deviation"): During one of Howard's fantasies, Takei, along with Katee Sackhoff, help Howard realize that he still has feelings for Bernadette. Takei's real life homosexuality is twice referenced in the episodes: once, when he first appears in Howard's fantasy, Sackhoff asks Howard if Takei's presence implies that Howard has homosexual tendencies, and the second reference occurs when Takei advises Howard about women's love preferences. Sackhoff asks Takei "How would you know?" and he responds "I read."

Neil deGrasse Tyson (Season 4, "The Apology Insufficiency") Appears as a colleague of Raj. Upon being introduced to Tyson, Sheldon tells him that he (Sheldon) is upset at Tyson's role in the demotion of Pluto from planet status. Initially, Tyson explains that he had no role in the demotion, but later attempts to apologize to Sheldon. Sheldon declines the apology, immediately after he himself apologized to Howard, who declined Sheldon's apology.

Stephen Hawking (Season 5, "The Hawking Excitation" and Season 6, "The Extract Obliteration"): After Sheldon's much-anticipated meeting with Hawking, he discusses Sheldon's research and points out a mistake. Sheldon protests by saying that he doesn't make mistakes, to which Hawking replies "Are you saying that I do?" When Sheldon realizes his research does in fact contain a math error, he faints in embarrassment, prompting Hawking to remark "Oh great, another fainter."

Mike Massimino (Season 5, "The Friendship Contraction","The Countdown Reflection",Season 6, "The Decoupling Fluctuation and "The Re-Entry Minimization"): An astronaut who appears as a future colleague of Howard who is set to join NASA's astronaut corps. Massimino reveals that his nickname is "Mass". Howard assumes the nickname is derived from Newton's second law, which states that force = mass times acceleration, but Massimino reveals that "Mass" is simply short for Massimino. Raj and Howard concoct an elaborate scheme to plant a seed in Massimino's mind to give Howard the nickname "Rocket Man" by having Howard set up the song "Rocket Man" as his ringtone on his cell phone, and Raj calling the cell phone during Howard's Skype conversation with Massimino. Their plan is thwarted when Howard's mother shouts to him that he needs to finish his Froot Loops, which triggers Massimino to give Howard the nickname "Froot Loops". He is heard on the phone in "The Launch Acceleration" and in the Soyuz capsule with Howard and cosmonaut Dimitri Rezinov, serving as their mission commander in "The Countdown Reflection".