Behind-The-Scenes Secrets About ‘The Big Bang Theory’

In 2007, Sheldon, Penny, Leonard and the rest of the quirky and lovable cast of characters from “The Big Bang Theory” debuted on TV. Although the show initially received mixed reviews, it didn’t take long to win fans over and become a No. 1 hit. It even spurred a spin-off, “Young Sheldon,” which premiered in 2017.

Even if you are a die-hard “TBBT” fan, there just might be a few fun facts you don’t know about the cast, the set or the show itself. And if the sitcom is not on your radar yet, these tidbits might pique your interest enough to turn you into a new enthusiast!

Jim Parsons Thought He Was Auditioning For A Game Show

Jim Parsons got a call to audition for a new show produced by Chuck Lorre. Not familiar with the writer and producer at the time, Parsons thought he would be auditioning for Chuck Woolery, host of numerous game shows. In 2014, Parsons, who plays Sheldon, explained to David Letterman that he thought he was trying out for a game show, joking, “I thought, ‘why are they so excited about it?'”

Opening Credits Typo

If you have a sharp eye, you might have noticed this unexplained typo in the opening its. In the timeline that scrolls by while the theme song plays, the dates read 93,000BC 92,000BC  and then 91,0009C. You can see it at 0:04 in this video clip from Narko The Rainmaker’s YouTube page.


Episode Names

You might not have paid much attention to the episode titles, but maybe you will now. Each show name is written as a scientific theory. In fact, it can be difficult to distinguish real scientific statements from episode names, as exemplified in this quiz on

‘Soft Kitty’ Lawsuit

Sheldon’s soothing song, “Soft Kitty,” sounds original, but in December 2015 the daughters of a nursery school teacher who penned a nearly-identical verse in the 1930s filed a lawsuit against “The Big Bang Theory.” A judge dismissed the case, saying the family failed to show they held a copyright on the lyrics.

Penny’s Missing Last Name

Even the fiercest “TBBT” fan cannot tell you Penny’s surname. This is because the writers have intentionally withheld this information.

In a 2013 interview with Vulture, executive producer Steve Molaro said, “What name could we possibly pick that would be satisfying at this point? You know, I don’t think we will [reveal it]. We’re kind of a superstitious lot here. We’ve made it this far without knowing Penny’s last name. I think we’re good not finding out.”

A Show by Any Other Name?

The original working title of “The Big Bang Theory” was “Lenny, Penny and Kenny.” To pitch the show, co-creators/executive producers Bill Prady and Chuck Lorre wrote a script together. They recruited some actor friends to play it out for CBS exec Les Moonves, and the rest is history.

The Belarusian Rip-Off

Imitation might be the sincerest form of flattery, but completely stealing someone else’s idea is flat-out wrong. A Belarus production company created a program called “The Theorists,” which was a blatant copy of “TBBT.”

In February 2010, Chuck Lorre wrote a message on one of the vanity cards shown at the end of each show stating in part, “When we brought this to the attention of the Warner Brothers legal department, we were told that it’s next to impossible to sue for copyright infringement in Belarus because the TV production company that is ripping us off is owned and operated by the government of Belarus. Having no other recourse, I’m hoping that this vanity card will be read by the fine folks making ‘The Theorists,’ and, wracked with guilt, they break down and send us some felt hats.”

Soon after, “The Theorists” was canceled.

Running Joke

The crew is apparently rife with practical jokers. Show writer Stephen Engel loved to prank his colleagues and, when he succeeded, he would shout, “Bazinga!” While the catchphrase from the writer’s room wasn’t initially written into any scripts, it eventually became a hugely popular catchphrase on the show.


There’s A Bazinga Bee

A researcher in Brazil named Andre Nemesio has discovered numerous species of orchid bees. Since some types of bees are endangered, he often gives newly-discovered insects catchy names to help attract more attention to bee research. Nemesio named one species “Euglossa bazinga” in the hopes that the Hollywood-adjacent name would garner attention — and hey, it worked.

And A Bazinga Jellyfish

In 2011, scientists discovered a small jellyfish off the eastern coast of Australia. Because it is only about the size of a grape, researchers believe it was formerly overlooked as a juvenile of another species. They named it “Bazinga rieki,” in part because the body resembles a seven-string harp called a bazinga — but also because it had tricked them by hiding in plain site, like a practical joke!

Bernadette’s Voice Is Phony

When Melissa Rauch auditioned for the role of Bernadette, she decided to stand out with a distinctive voice.

“That’s actually my real voice and this is my fake voice,” she joked during a Comic-Con panel.

Could you imagine Bernadette any other way?

Leonard’s Glasses? Also Fake!

If you look closely, you will notice that Leonard’s glasses are actually lens-less. Johnny Galecki wore glasses intentionally because he thought they suited Leonard’s character. However, the lenses reflected the lights during filming. Galecki solved the issue by just popping out the lenses.

Who Else Wears Glasses?

Leonard is the only male main character on the show who wears glasses. On the flip side, Penny is the only female primary character who does not wear glasses. However, Mayim Bialik is the only cast member who typically wears them in real life.

Props to Props

Actor Wil Wheaton has portrayed a fictionalized version of himself on “TBBT” more than a dozen times. In 2010, he snapped a photo of the coffee table in Leonard and Sheldon’s apartment and shared it on his personal blog.

“This is an example of the attention to detail that is everywhere on every set of ‘The Big Bang Theory,'” he wrote. “It would be really easy to just toss a few random magazines and soda cans there, because it’s very unlikely that they’ll ever be seen in this much detail, but at every level of production, they make a concerted effort to ensure that everything is authentic.”


Sheldon and Leonard were named to honor the classic “Dick Van Dyke Show” producer Sheldon Leonard. In addition, Leonard’s last name is Hofstadter and Robert and Douglas Hofstadter (a father and son) were notable scientists. Finally, Leonard’s middle name is Leakey, after famed paleontologist Louis Leakey.

Jim Parsons’ Musical Ability

There are many folks who’d never near of a theremin — a unique musical instrument that is played without being touched —until watching “TBBT.” In real life, Parsons is an accomplished piano player, but the theremin — Leonard’s instrument of choice — was new to him. However, he took on the challenge and learned how to play the electronic instrument for the show.

Jim Parsons Is Not A Trekkie

On the show, Sheldon is a huge sci-fi fan. But the actor who plays him? Not so much. Parsons has admitted during past interviews that he had never seen any of the “Star Trek” films or watched a single episode of “Dr. Who.”

Sheldon’s Shirt Color Clues

Clever “TBBT” fans have observed that the shade of Sheldon’s shirt (say that five times fast) often corresponds to his mood. For example, if he is wearing a red t-shirt, it might indicate that he is angry in a scene. And as a superhero fan, Sheldon is particularly fond of his Green Lantern shirts and his Flash shirts.

The Flash Nods Back

Sheldon Cooper loves the Flash and it seems like the feeling is mutual. Many viewers of the TV show “The Flash” have spotted the character Cisco Ramon, played by Carlos Valdes, wearing shirts with “TBBT” jokes or catchphrases on them.

Penny’s Purse

Eagle-eyed fashion fans will notice that Penny has been carrying the same bag since Season 1, episode 2 — which is going on 12 years! According to HelloGiggles, it is a Lucky Brand slouch hobo bag. Hey, when you find a classic, stick with it!

The Equations Are Real

A whiteboard crammed with scientific equations sits at the back of Leonard and Sheldon’s apartment during most episodes. It would be easy enough for set designers to doodle scientific-looking symbols and text on the board. However, the equations are all accurate and have been approved by a physics professor from UCLA.

Address Easter Eggs

Amy Farrah Fowler lives in apartment 314, which probably was not an accident. The value of pi in decimal form is 3.14. Wil Wheaton’s house number is 1701, which is the same as the U.S.S. Enterprise’s hull number on “Star Trek: The Next Generation.” (Wheaton, of course, was an actor on “TNG” from 1987 until 1994.)

Science Advisor on Retainer

The creators of “TBBT” take great care to ensure accuracy throughout the sitcom. Physicist David Saltzberg is the show’s official science advisor.

“People will randomly meet up with me and say, ‘You know, I really appreciate that the science is correct,'” Saltzberg told Symmetry Magazine. “And the truth is, I’m just living in terror of making a mistake because I know I’ll get a hundred emails if anything is wrong.”

Jim Parsons Failed Science

It’s probably a good thing that there’s a physicist on-set for fact checking because Parsons told Time magazine that the one class he failed in college was a science class (meteorology, to be exact). It probably also helps that Mayim Bialik, who plays Amy, is a real-life neuroscientist!

The NASA Team Behind The Mars Rover Visited The Set

The real-life NASA scientists responsible for the Mars Curiosity rover landing paid a visit to the “Big Bang Theory” set. It’s anyone’s guess as to which group was more star-struck!