Why Mayim Bialik's The Big Bang Theory Casting Makes No Sense

"The Big Bang Theory" may have broken its own reality by casting Mayim Bialik in its third season. That's because the show mentioned the actress (by identifying details, though not by name) back in season 1 — a reference that made her later appearance a bit more meta and paradoxical than the show usually gets.

Bialik comes up in the show's thirteenth episode, "The Bat Jar Conjecture," when Sheldon (Jim Parsons) gets booted from the core group's physics bowl team. In search of a new fourth member, the guys start brainstorming, and Raj's first idea is a bit out there. "You know who's apparently very smart, is the girl who played TV's Blossom," Kunal Nayyar's character says. "She got a PhD in neuroscience or something!" 

It's a great bit in the moment, since Raj clearly isn't thinking practically and is sincere in his hope that Bialik (by that point known for her considerable studies as much as her on-screen role) will pop by to help them out. "Raj, we're not getting TV's Blossom to join our physics bowl team!" Johnny Galecki's always-annoying Leonard shot back, in a moment that seems perfectly designed to go viral later on.

Despite Raj's apparent moment of precognition, "The Big Bang Theory" team had no idea at that point that Bialik would one day end up with a major role on the show. In Jessica Radloff's book, "The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series," executive producer Steve Molaro said he came up with the idea of Sheldon meeting a character who's essentially a girl version of himself at the end of season 3, but had no idea whether or not the Amy character would ever return. For her part, Bialik says she had never seen "The Big Bang Theory" at the time of her audition — not even the "Blossom" shout-out.

"Someone told me I was mentioned on 'Big Bang' in an earlier season, so I thought it was a game show, like, I must have been on 'Jeopardy!' as an answer," the actress said in interviews for the 2022 book. She admitted: "I literally Googled Jim Parsons the day of the audition 'cause they were like, 'We want a female Jim Parsons.' That's how I prepared for the audition – watching Jim Parsons on YouTube for thirty seconds." According to Radloff, Bialik returned to acting for a practical reason: her UCLA health insurance was set to expire. The actress later said that she never watched "The Big Bang Theory" even after she was on it.

In the end, the casting of Amy Farrah Fowler came down to Bialik and Kate Micucci, who would later play Raj's girlfriend Lucy. According to Molaro, series co-creator Chuck Lorre really loved that Bialik had a PhD in neuroscience and "could bring an authenticity to the science and to the intelligence of the character." Bialik's bona fides here are a bit ironic in retrospect, as she's since become known for supporting pseudoscientific claims. Physics bowl team aside, though, when the gang finally really had a chance to get TV's Blossom on their team, they did. 

"The Big Bang Theory" leaned into the reality-bending "Blossom" references at least one other time, in the season 6 episode "The Holographic Excitation," when the pair brainstorm a list of potential Halloween costume ideas. In one scene, a Venn diagram shows "Blossom & Joey" listed as one of the ideas Amy likes, a reference to her "Blossom" character and Blossom's older brother, played by Joey Lawrence. In the end, the pair dress as C-3PO and Raggedy Ann, restoring balance to the "Big Bang Theory" universe once more.