Hit CBS sitcom The Big Bang Theory faded from the broadcast TV universe in May 2019, but lives on in fans’ hearts and minds (and in prequel series Young Sheldon). It made stars out of Jim Parsons, Simon Helberg, and Kunal Nayar and added to Kaley Cuoco and Johnny Galecki’s sitcom résumés, but just as imporant, the show — which premiered 15 years ago, on September 24, 2007 — gave dozens more stars a chance to play themselves.
For instance, Ellen DeGeneres, Nathan Fillion, and Sarah Michelle Gellar had cameos on The Big Bang Theory. And plenty of sci-fi stars teleported onto set, including Mark Hamill, Carrie Fisher, James Earl Jones, Katee Sackhoff, William Shatner, and George Takei.
But we’re here to talk about the nerdiest of the guest-stars — less science fiction, and more science nonfiction, if you will. Scroll down to see our picks in action.
Buzz Aldrin
In Season 6, Episode 5, “The Holographic Excitation,” the second person to walk on the Moon played a boastful version of himself, bragging about his accomplishments to uninterested trick-or-treaters. (“I walked on the moon,” he tells one kid. “What have you done?”)
Bill Gates
For Season 11, Episode 18 — the aptly-named episode “The Gates Excitation” — the Microsoft co-founder did his best to ward off Leonard’s (Galecki) emotional fanboying.
Stephen Hawking
Hawking, who died in 2018, boasted seven Big Bang Theory episodes on his filmography — starting with Season 5, Episode 21, “The Hawking Excitation,” in which Sheldon (Parsons) is stunned to realize he gave the theoretical physicist an erroneous paper about the Higgs boson particle.
Mike Massimino
This NASA astronaut-turned-Columbia mechanical engineering professor — who holds the distinction of being the first person to tweet from space — guest-starred in six Big Bang Theory episodes. In the first of those appearances — Season 5, Episode 15, “The Friendship Contraction” — he gives Howard (Helberg) the astronaut nickname “Froot Loops.”
Elon Musk
In Season 9, Episode 9, “The Platonic Permutation,” Howard is surprised to discover that the Tesla CEO is his fellow dishwasher in a Thanksgiving soup kitchen. (And of course, Howard immediately starts angling for a SpaceX job.)
George Smoot, Kip Thorne, and Francis Arnold
In Season 12, Episode 18, “The Laureate Accumulation,” Sheldon tries to curry favor with these Nobel-winning scientists — two physicists and a chemical engineer, respectively — but all three reject the cookies he sent them. (The cookies almost win over Arnold, and then she realizes that they’re oatmeal-raisin.)
Neil deGrasse Tyson
Raj (Nayyar) starts a Twitter feud with this astrophysicist in “The Conjugal Configuration,” the sitcom’s 12th season premiere and the second of Tyson’s appearances on the show. (The Cosmos host eventually calls Raj up for a “deGrasse-kicking,” telling him, “The next time you pick up your phone, remember, I’m the guy who kicked Pluto out of the Solar System.”)
Steve Wozniak
Wozniak — or “the Great and Powerful Woz,” as Sheldon calls him — has a cameo in Season 4, Episode 2, “The Cruciferous Vegetable Amplification.” When Leonard starts to explain that Wozniak is one of the co-founders of Apple, Penny (Cuoco) says, “Yeah, I know who he is — I watch Dancing With the Stars.” (The electrical engineer competed in DWTS Season 8.)
