Behind-The-Scenes Secrets And Surprising Facts About The Big Bang Theory

The Big Bang Theory burst onto our screens in 2007, introducing us to the goofy characters and sticky situations that we’ve come to know and love.

As the series has been around for a decade, it’s easy to think we know all there possibly is to know about it – but think again. We’ve done some digging and got the scoop on behind-the-scenes gossip and other little-known facts.

Grab your popcorn, sit back and join us as we take a look at the ins and outs of The Big Bang Theory.

Jim Parsons Really Plays The Theremin

Photo Credit: Big Bang Theory

The theremin is one of the most difficult instruments that you can play. If we’re honest, we’re not entirely sure what it does, other than making a terrible sound. The little box consists of two metal antennas that sense the position of the player’s hands.

Its oddness made it entirely suitable to be the instrument of choice for Sheldon, but in reality, Jim Parsons is among the few who can play one of these things. “I’ve loved the theremin ever since I heard the original Star Trek theme,” Cooper tells his flatmates. Like character, like actor!

The Show Was Given Multiple Season Renewals

Photo by Christopher Polk/Getty Images for The People’s Choice Awards

In the world of TV, it’s pretty rare for a series to get the go-ahead for more than one season at a time. After all, shows can go from the most watched thing on the box to the least watched in a hot minute, so studios have to protect their interests.

So, when CBS renewed the show for not one, not two, but three seasons in 2011, it was a pretty big deal. The network knew this wasn’t a one trick pony. In 2014 when that run was over, it was renewed again for a further three years. CBS is riding this gravy train all the way to the bank.

The Cast Hid Some Serious Injuries On Camera

Photo by Michael Tran/FilmMagic

Just because you’re in an award-winning series, that doesn’t stop some pretty crappy things from happening off-set. In fact, some of the main cast members had to hide extremely serious injuries and breaks in order to keep filming as normal and not disrupt the storylines.

During season 4, Kaley Cuoco, aka Penny, broke her leg after she fell off of a horse. The star missed a couple of episodes to get back on her feet, but when she returned had to shoot her scenes from behind a kitchen counter. Similarly, Mayim Bialik who plays Amy had to hide an injured right hand during season 6.

Penny Was Originally Played By Amanda Walsh

Jonathan Leibson / Contributor

At the very beginning, Penny was a very different character from the lovable klutz we know and love today. Amanda Walsh of Beauty and the Briefcase was originally cast in the part of “Katie” for the first pilot and was a much tougher character. When the audience reacted badly, the studio knew they had to make some changes.

Writers gave the character a revamp and a new name, with Kaley Cuoco coming in to shoot the second pilot as Penny. As they say, the rest is history – but wouldn’t it be weird if Penny didn’t exist at all? It’s unbearable to think about.

Every Prop Is Carefully Thought Out

Photo Credit: Big Bang Theory

When Star Trek actor Wil Wheaton first appeared on the show in season 3 as a modified version of himself, he snapped a picture of one of the most-seen props in Sheldon and Leonard’s apartment – their coffee table. Uploading the candid to his blog, the actor pointed out the thought that had gone into it.

Set designers paid close attention to detail, even though we never really directly see what’s on the table. It’s littered with high-brow magazines such as Mental Floss and several snacks like Red Vines licorice. We bet you never knew that.

The Character Names Come From Real Life People

Roberto Serra – Iguana Press / Contributor

It’s pretty easy to not put much thought into a character’s name. After all, we’re more interested in their on-screen antics than looking at their birth certificates, but creator Chuck Lorre took inspiration from real people to carefully name the characters.

Howard Wolowitz comes from a former colleague of Lorre’s, and Leonard and Sheldon are named after iconic TV producer Sheldon Leonard. Leonard’s last name stems from two famous scientists, Douglas Hofstadter (above) and Robert Hofstadter. We’re not sure where Penny comes from, but we bet there’s an equally quirky story behind that too.

The Show Had A Copycat Series

Photo by Albert L. Ortega/Getty Images

It doesn’t matter what industry you’re in, you can always be certain that someone will want to ride on the coattails of your success – but it’s especially true in TV. A show called The Theorists appeared on air in Belarus in 2010, shocking fans.

The ill-fated series was similar in more ways than just the name, following a group of characters that were almost identical. Before any lawsuits could be filed, the actors of the Belarus version quit when they realized the idea had been stolen from American television. All’s well that ends well, we say.

The Apartment Location Is Real

Photo Credit: Big Bang Theory

The characters spend a lot of time in Leonard and Sheldon’s apartment, number 4A, making it one of the most recognizable sets. In the past, the gang has mentioned that the building is located in Pasadena at 2311 Los Robles.

Shockingly, unlike most sitcoms, the address is actually real – but the apartment building that is supposed to be across the street from the Colorado Avenue Chevron Station simply isn’t there. A mighty shame for those who believed it to be real and trekked all the way down there. We’re not talking from experience or anything…

Two Major Cast Members Secretly Dated

Photo by Kevin Mazur/WireImage

Johnny Galecki who plays Leonard is no stranger to mixing work and pleasure, having dated his on-screen love interest while working on Roseanne. Although the couple kept it quiet at the time, Kaley Cuoco revealed in 2010 that she and Galecki dated for two years after meeting on the show.

The relationship lasted through the first few seasons of the series but came to an amicable end. Thankfully, the two remain friends, which certainly alleviates any awkwardness when it comes to working in close proximity. Wouldn’t it be nice if our lives were that easy? We’d all be so lucky.

Keep reading to see who they’re with now.

Kaley Cuoco Shares Her Love Of Horses With Her Fiance

Photo: Rachel Murray/Getty Images for Netflix

Off-screen actress Kaley Cuoco has a passion for horses and competes in equestrian jumping events. She found love with fellow equestrian Karl Cook, and the couple became engaged on Cuoco’s 32nd birthday in 2017.

Often spotted attending the derby and riding horses together, Kaley is over the moon about her husband-to-be. She told People, “I think meeting people that are involved [in the same things as you] — I think that the horse connection is special. He’s special.”

Mayim Bialik Is An Actual Neuroscientist

Photo by John Lamparski/Getty Images

Mayim Bialik, who plays Amy, first came on board in season three after a dating app paired her and Sheldon. While Amy is a super-smart neurobiologist, it would be incredibly unusual for the actor in question to be similarly qualified – but that’s just what happened here.

Bialik, who also played the title role on the TV series Blossom, earned her doctorate in neuroscience in 2008, giving her the distinction of being the only actor on the show with a terminal degree. Before she joined the cast, Raj mentions her in an early episode. “You know who’s apparently very smart, is the girl who played TV’s Blossom.” You got that right, Raj.

See who her partner in real life is, next.

Bialik is Currently Single, We Think?

Photo: Jason Kempin/Getty Images

Mayim Bialik was married to Michael Stone from 2003-2012 and had two sons together. After the couple split, Bialik’s character was married on the show. She said the scenes were hard for her, as a divorced woman, and brought back some difficult memories. Bialik told Metro, “The first time I read those lines, I got emotional for real, because it is my job to embody this character and to feel what she feels. She is me and I am her, I suppose.”

If she’s in a relationship now, she keeps it under wraps, all the while putting out hilarious videos on dating and wedding tips on YouTube. She’s also the author of a New York Times bestseller, Boying Up, about her experience raising her sons.

Jim Parsons Has Never Seen An Episode Of Star Trek

Photo Credit: Big Bang Theory

There’s an old adage that says if you’re asked if you can do something in an interview, you say yes and figure out how to do it later. This must’ve been the case with Jim Parsons when he landed the role of Star Trek loving Sheldon. Despite playing a character who loves the show, the actor has never seen a single episode.

It doesn’t just end at Star Trek, either. Sheldon is also a big fan of the British series Doctor Who, which Parsons has also never seen. Instead, he likes to watch American Idol, Three’s Company, and Grey’s Anatomy. We all have our crosses to bear.

The Theme Song Caused A Legal Battle

Photo by Lester Cohen/WireImage

The Big Bang Theory has an iconic theme song that gets stuck in your head as soon as you hear it. Chuck Lorre and Bill Prady attended a concert by the Barenaked Ladies when frontman Ed Robertson freestyled a rap about the universe.

The pair then approached the band to write the theme tune and they gladly accepted. Stephen Page was part of the group at the time but left in 2009. In 2015, he filed a lawsuit against the rest of the band, alleging that he never received the 20% in royalties for the song that he was promised. As you can imagine, that would’ve been a pretty large sum.

Finally, The Finale


After an amazing 12-season run, The Big Bang Theory aired its last ever episode on May 16. CBS shared some teaser images prior to the finale. Kaley Cuoco took to social media to clarify some confusion among fans. “People are freaking out because they thought there were two episodes left of Big Bang and on the last episode is said that next week is the final,” she wrote. “Technically it’s in one night, but it’s two episodes so don’t panic.”

Cuoco added that ET would be doing a special right before the finale, and that she and Johnny Galecki would be hosting another special after Young Sheldon. The show’s cast also made an appearance on the Late Show with Stephen Colbert after the finale aired.

So what happened in the finale? SPOILERS AHEAD!

Surprises In The Series Finale

Photo Credit: Big Bang Theory

In the two-episode finale, Sheldon (Jim Parsons) and Amy (Mayim Bialik) win the Nobel Prize in physics, and the group of friends all take a trip together to celebrate. Surprises revealed during the finale included a cameo from Sarah Michelle Gellar, news of Penny’s pregnancy, and the long-broken elevator finally getting repaired.

Fans thought the show’s ending was touching and a great way to honor the friendships between all the characters. 18 million people tuned in to catch BBT’s final moments,

Kevin Sussman Had To Be Coached Through The Hot Tub Scene

Photo Credit: Big Bang Theory

Lovably awkward comic book store owner Stuart finds himself the brunt of the joke on many occasions. The character went from series guest to series regular thanks to his popularity and is portrayed by actor Kevin Sussman. While Sussman is old hat at acting, there are certain situations he can’t cope with – those involving water.

“The Hot Tub Contamination” is a favorite episode for fans. Stuart goes over to use Howard and Bernadette’s hot tub when he thinks they’re out of town. When he hears the door unlocking, he hides under the water – but Sussman is terrified of his head being submerged. So much so, that he had to undertake special coaching to get through the scene.

The Actors Hate Their Costumes

Photo Credit: Big Bang Theory

Hey, no one said that working in TV was easy. The days are long, the scripts can be complicated and the costumes can be extremely uncomfortable. Some of the actors on Big Bang utterly hate their character’s outfit choices.

Kunal Nayyar, who plays Raj, has to spend 20 minutes having his hair straightened before every shoot as it’s naturally curly. He’s also not a fan of the heavy sweaters and wishes he could dress like Penny, in shorts and tank tops. Simon Helberg, aka Howard, wishes he didn’t have to wear so many different types of belts, as they often dig into his stomach when he sits down.

There’s A Touching Reason You Never See Baby Halley Wolowitz

Photo Credit: Big Bang Theory

In season 10, Howard and Bernadette welcomed their first born, Halley Wolowitz. Like any self-respecting show, the pregnancy is heavily detailed in the build-up to the birth, but viewers never physically see the new cast member. You hear the baby cry, but we’re never shown her, which continues as the show goes on.

While it’s partly so they don’t have to bring a baby on set, it’s also supposed to be a tribute to actress Carol Ann Susi, who played Howard’s mother. Viewers never saw Howard’s mom either, just heard her shrill voice shouting to her son off-screen. Susi passed away in 2014, and producers wanted to pass down the off-screen voice to a new generation.

See who Melissa Rauch is married to in real life next.

Melissa Rauch is Married to a Writer

Photo: Jamie McCarthy/Getty Images

Melissa Rauch, who plays Bernadette on the show, is married to writer Winston Rauch. Together they’ve collaborated with her on projects such as The Miss Education of Jenna Bush. The couple married in 2006 and have a daughter named Sadie.

Rauch was vocal about her sadness in suffering a miscarriage before her daughter was born and shared her experience in an interview with Glamour to show her support for other women in the same situation.

The Cast’s Salary Is Drastically Unequal

Photo Credit: Big Bang Theory

Throughout the course of the show, the salary of the cast has been a source of contention. In 2013, Jim Parsons, Kaley Cuoco, and Johnny Galecki decided to stick together to negotiate a huge salary increase. It’ll blow your mind. We’re not talking about small change here.

Up until that point, they were paid $350,000 an episode. When the negotiations ended, they each bagged themselves a cool $1 million per episode. Simon Helberg and Kunal Nayyar tried to get the same amount but left the table with $750,000. In 2017, all of the stars agreed to take a pay cut of $100,000 per episode so that Melissa Rauch (Bernadette) and Mayim Bialik (Amy) could each receive $425,000.

Explaining Story Lines Was Really Awkward

Photo Credit: Big Bang Theory

Casting legendary Star Trek stars Wil Wheaton and George Takei was an important step for The Big Bang Theory, but explaining the storylines to the guests was as awkward as it can get. For a start, Wil plays a pretty horrible version of himself, while George is part of a sexual fantasy.

It fell to Bill Prady to explain the parts to the stars. “I didn’t know this guy and I had to call him and say, you’re playing yourself…but you’re a real [expletive]!” Prady explained. When it came to calling George, things didn’t get easier. “How do I say to this guy that he’s a possible homosexual fantasy? Finally, I said, ‘So you know you’re gay, right?!’ and he said, ‘That’s news I’ll tell my husband!'”

The 2007 Writer’s Strike Almost Tanked The First Season

Charley Gallay / Stringer

In 2007 the Writer’s Guild of America went on strike, embroiled in a labor dispute with the Alliance of Motion Picture and Television Producers. It took a substantial amount of time for it to be resolved – four months to be exact. The show had been on the air for eight episodes when the strike began.

CBS had no choice but to run the same eight episodes for that entire duration – amazingly, viewers kept watching. When the writers returned they had two months to write and film nine episodes to complete the first season. They managed it, and the show was a success despite airing with limited episodes.

Sheldon Was A Stud In The Pilot

Photo Credit: Big Bang Theory

We all know that shows rarely stay as they’re originally written. The characters develop, as do the storylines and the sets. However, some changes are more dramatic than others. In the un-aired pilot, Sheldon was a stud, hooking up with girls and having romantic liaisons.

When it didn’t seem to really fit, they altered the character to be the lovable, awkward afraid-of-human contact Sheldon that we now know and love. It’s difficult to picture him being man-about-town, spreading his wild oats. It just wouldn’t have been the same.

The Soft Kitty Song Is Real

Photo Credit: Big Bang Theory

The adorable bedtime song that helps Sheldon calm down is one of the most popular parts of the show. “Soft kitty, warm kitty, little ball of fur. Happy kitty, sleepy kitty, purr, purr, purr,” Sheldon sings as Penny rubs his stomach. It’s so adorable, it hurts.

As it turns out, the song wasn’t just something the writers made up but a real-life nursery rhyme. Producer Bill Prady’s daughter sang the song in pre-school. It originated in Australia and that’s where the teacher learned it. He liked it so much, it just made sense to put it in the series.

The Show Filmed Two Pilots

big bang theory aired pilot
Photo Credit: Big Bang Theory

The reason Amanda Walsh didn’t launch the season as “Katie” is because CBS didn’t like the first pilot the show created. Creator Check Lorre even said that the initial pilot “sucked.” You can find the unaired pilot on Youtube.

Along with the different Penny role, the first pilot featured a different theme song, and no Raj or Howard. Instead, two female characters acted in the episode, and were replaced upon the second pilot.

The Writer Addressed Sheldon’s “Diagnosis”

sheldon big bang theory
Photo Credit: Big Bang Theory

For years, fans have speculated that Sheldon either has Asperger’s syndrome or Autism due to his anti-social nature. Writer and producer William Scott Prady did address these theories at one point, but his answer hasn’t satisfied viewers.

Prady told TV Squad’s Allison Waldman that he never had any diagnosis in mind while writing the character. “We write the character as the character,” he said. “A lot of people see various things in him and make the connections. Our feeling is that Sheldon’s mother never got a diagnosis, so we don’t have one.”

Will Wheaton Was Casted Through A Tweet

Actor Wil Wheaton attends CBS'
Ethan Miller/Getty Images

Star Trek actor Will Wheaton wasn’t pursued for his role in Big Bang Theory until he tweeted about the show. “I was talking on Twitter about how much I loved the show and how I thought it was really funny,” Wheaton told radio host Larry King. He said that executive producer Steven Molaro saw the tweet and offered Wheaton to come in to a taping.

Since then, Wheaton has appeared in Big Bang Theory throughout several seasons, playing a delightfully evil version of himself. Fans wouldn’t have seen this fantastic character on air if it hadn’t been for this one tweet.

Bazinga! Is A Species Of Bee

bazinga the big bang theory
Pinterest/Mrs Hood

In 2013, Brazilian biologists discovered a new species of orchid bee that is often mistaken for a similar species, Euglossa ingita. They searched for a name that would differentiate this new species, and eventually settled on Euglossa bazinga.

Writer Stephen Engel originally coined Bazinga! based on a personal catchphrase we would use after playing pranks on his friends. Parsons later said that they added it to the script last minute. Although the phrase has appeared before Big Bang Theory, most notably in The X-Files, it’s still credited as the show’s iconic catchphrase.

The Next Guest Star Is…Pope Francis?

Pope Francis waves to the faithful
Franco Origlia/Getty Images

After having on Stephen Hawking and Leonard Nimoy, the producers have joked that their next dream guest star would be Pope Francis. As the final season wraps up the show for good, it seems that the pope became too busy to make the CBS show.

“We’ve done some episodes about science and religion,” writer Bill Prady said, “and we thought Pope Francis might be good. He’s probably too busy now.” Of course, the producers only meant this as a joke…right?

The Sets Are Constantly Redesigned

big bang theory stairs set

Although the show’s set does exist as a real apartment building, and looks like one, the crew only uses one set. Floors two, three, and four are all the same room that’s redecorated for every scene. If you look closely at the staircase, you’ll notice shots where the scuff marks on the molding appear identical in every level they walk up the stairs.

If you ever want to visit the set (remember, we’re NOT talking from experience or anything), you’ll only see one room and staircase. That’s almost more of a letdown than nothing having a real apartment at all.

Roseanne…Roseannes Everywhere

Actors Laurie Metcalf, Sandra Bernhard, Alicia Goranson, John Goodman, Roseanne, Michael Fishman and Sara Gilbert attend the DVD launch of
Mark Mainz/Getty Images

The show Roseanne aired for thirty years and had many seasons overlap with Big Bang Theory. Surprisingly, many actors also overlap in both Roseanne and Big Bang Theory. Laurie Metcalf, who plays Sheldon’s mother, played Jackie Harris in Roseanne. Sara Gilbert played Leonard’s former girlfriend in Big Bang Theory and Johnny Galecki’s girlfriend in Roseanne.

The shows are both long-running sitcoms, and were produced and written by Chuck Lorre. With the final season finishing up, few Roseannes will sneak into minor roles…or so we can assume.

Bernadette Didn’t Originally Have A High-Pitched Voice

bernadette melissa ranch big bang theory
Photo Credit: Big Bang Theory

When Melissa Rauch first came onto Big Bang Theory, her high-pitched voice wasn’t written into the character. She just decided to talk that way during the audition. “That’s actually my real voice, and this is my fake voice,” she joked during a Q&A.

Nowadays, it’s impossible to imagine Bernadette without her distinctive voice. The actress said that she imitated her mother’s voice “without the Jersey” spontaneously while auditioning. Apparently, it worked, because she developed the popular character we know and love today.

Howard’s Room Is Filled With Female Superheroes

howards room
Photo Credit: Big Bang Theory

If you pause the show and scan Howard’s (and later Bernadette’s) room, you’ll discover that all the figurines and posters feature female superheroes or science fiction characters. The only non-woman figurine features Jabba the Hutt, but also Princess Leia sitting in front in her slave girl costume.

Later in the series, they add a Bernadette figurine to the collection after Raj got a 3D printer. It’s no wonder that Bernadette would fit in among Howard’s model superwomen. The rest of the room features space exploration toys–fitting.

A Hidden Tribute To Howard’s Mom

sheldons fridge carol ann susi tribute
Michael Yarish/CBS Broadcasting, Inc.

Although Howard’s mom is never actually seen–only heard from the next room–the producers placed a small tribute to the actress who played her, Carol Ann Susi, who passed away in 2014. A small picture of her hangs on the side of Sheldon and Leonard’s fridge.

You can’t see the photo clearly on camera, but in a behind-the-scenes DVD feature, the actors reveal that it’s her. In a way, the tribute fits in with Howard’s mom never actually appearing in person.

The Actors Never Eat While Filming

university canteen big bang theory
Michael Yarish/2013 Warner Bros

Despite the numerous University canteen and dinner scenes, the actors don’t actually eat their food most of the time. Howard often pretends to chew his food, while Sheldon and Leonard mainly mess around with their forks. These scenes mainly feature the actors talking.

Keep an eye out during these scenes, and you’ll notice little to no eating actually happening. Even so, Amy and Penny sometimes actually eat their food in certain scenes. At least it’s going somewhere–otherwise, it seems like a waste of food.

Most Romantic Relationships Were Foreshadowed

amy and sheldon big bang theory
Photo Credit: Big Bang Theory

Whenever a female character first appeared on the show, the first person to speak to them ended up becoming their partner. When Penny is introduced, Leonard first speaks to her in “The Creepy Candy Coating Corollary.” When Bernadette is introduced in “The Lunar Excitation,” Howard first speaks to her. Finally, Sheldon first speaks to Amy when she’s introduced.

Although the writers have never confirmed these scenes as planned out foreshadowing, many fans speculate that the plot development was intentional. Of course, few people suspected this theory when the characters first came into the plot.

Kaley Cuoco’s Sister Taught Her The Flash Mob

Briana Cuoco and Kaley Cuoco
Jason Kempin/Getty Images

Kaley Cuoco’s sister, Bri, choreographed the cast’s flash mob to “Call Me Maybe.” The performance landed her two co-creator jobs on Chuck Lorre’s shows and a 50-dance performance on Two and a Half Men. She also performed on The Voice in 2013.

Bri Cuoco has played minor roles on Big Bang Theory as well. She appeared as the new fiancée to Penny’s ex-boyfriend, and played a woman who accepts a marriage proposal in the background of one Valentine’s Day special episode.

Complimenting The Boss

Executive Producer Chuck Lorre speaks before the cast of
Photo by Albert L. Ortega/Getty Images

In the episode “The Fish Guts Replacement,” Sheldon claims that his favorite cartoon song is the theme for Teenage Mutant Ninja Turtles. The writers may have decided to suck up to the boss with this reference, as producer Chuck Lorre wrote that exact theme song.

“I wanted to do the theme song for the ‘Turtles’ the moment I heard about it,” Lorre said in an interview with Archive of American TV. He said that in the ’80s, he actively pursued both script writing and music.

Leonard’s Glasses Don’t Have Lenses

leonard big bang theory
Photo Credit: Big Bang Theory

You’d think that after a couple of seasons of Big Bang Theory airing, more fans would’ve noticed that Leonard’s glasses have no lenses. But it took until season ten for fans to notice and bring it up to Johnny Galecki. “Oh, man. You’re killing the magic,” Galecki said told the Huffington Post after being asked about it.

Galecki said that the glasses originally had lenses, but whenever he looked up as Jim Parsons, his lenses would catch the studio lights. The took the lenses out, only to have Galecki occasionally poke his finger through an empty frame and ruin a scene.

The Show Wasn’t Pitched In A Traditional Way

Writer/producers Bill Prady and Chuck Lorre attend the Inside
Photo by Ethan Miller/Getty Images

To pitch a show idea, most creators write a script for the pilot and weave together a speech to present to company like CBS. But co-creators Chuck Lorre and Bill Prady had a more extravagant idea. In a panel at PaleyFest 2009, the creators revealed that they wrote a complete script, hired actors, and “put on a show” for CBS President Les Moonves.

According to Lorre, the “crazy” experience actually worked. Although the original pilot underwent major changes, the show get rolling through season twelve.