The untold truth of The Big Bang Theory

The Big Bang Theory quietly debuted on CBS in 2007. Once reruns of the show started appearing on local stations and cable, the ensemble sitcom exploded in popularity, and original episodes routinely rank near the top of the weekly network TV ratings while reruns dominate the list of most-watched cable shows. Here's a look at some stories and scandals behind the scenes of the America's favorite sitcom about science nerds.

Big changes were made after the pilot

The Big Bang that's aired for a decade is very different from the pilot episode presented to CBS in 2006. While he's now depicted as asexual and mystified by romance, Sheldon (Jim Parsons) was sexually active in the pilot. There was also no Penny (Kaley Cuoco); instead, the attractive neighbor was a tough, not-very-friendly woman named Katie (portrayed by Amanda Walsh). Leonard (Johnny Galecki) wore suits instead of hoodies, and there was one other change: The theme song was Thomas Dolby's 1983 hit, "She Blinded Me With Science." CBS passed, but asked creators Chuck Lorre and Bill Prady to rework the show and submit another pilot. They did (adding an original theme by Barenaked Ladies)—and it made it to the air in 2007.

Melissa Rauch doesn't sound like Bernadette in real life

Bernadette's mousy, high-pitched voice—and loud moments of screaming rage—don't come naturally to her portrayer, Melissa Rauch. Although she doesn't sound like Bernadette in real life, Rauch took her inspiration from a source close to home: her own mother. Although the two women share vocal DNA, they have one major difference—Bernadette lacks her real-life counterpart's thick New Jersey accent.

The main three stars get paid big bucks

Production of the show's eighth season was delayed in 2014 due to contract re-negotiations between the cast and Warner Bros TV. Ultimately, CBS renewed the show for an unprecedented three seasons (keeping TBBT on the air through 2017) and Jim Parsons, Johnny Galecki, and Kaley Cuoco secured a salary of $1 million per episode—each.

The rest of the cast earns a lot, too (but not as much as the stars)

Simon Helberg (Howard) and Kunal Nayyar (Raj) re-negotiated their new contracts collectively, winding up with salaries of around $750,000 per episode. A settlement was reached the day before their old contracts ran out, and the duo would've reportedly been written out of the show had they not accepted the deal.

Some cast members took a pay cut so others could get a pay raise

While some members of the Big Bang Theory cast got the big bucks of $1 million an episode, Melissa Rauch and Mayim Bialik did not. They both joined the show later on, so for the last few seasons, they've been raking in a relatively meager $200,000 per episode. Not anymore. For the show's 11th and 12th seasons, the highest-paid cast members agreed to a pay cut of $900,000 an episode each, with the expressed intent that the extra money goes to giving Rauch and Bialik a raise, who will now each earn about $450,000 an episode.

Johnny Galecki and Kaley Cuoco secretly dated for years

While Cuoco has been tabloid fodder due to her brief marriage to (and high-profile divorce from) tennis player Ryan Sweeting, she avoided the spotlight while she was in her previous relationship…even though it was with a co-star on her top-rated TV show. Cuoco and Johnny Galecki dated from 2007 to 2009 and kept it a secret from not only the media, but from the Big Bang cast and crew.

Mayim Bialik was on the show before she was on the show

In the 2008 episode "The Bat Jar Conjecture," Sheldon quits the group's physics bowl team. Raj aims high in his suggestion for a replacement, naming "the girl who played TV's Blossom," as she'd earned a Ph.D in real life. That actress is Mayim Bialik…who later joined the cast as Amy Farrah Fowler. Also under consideration for that role was actress and Garfunkel and Oates musician Kate Micucci. She was edged out for the part by Bialik, but producers liked her so much that they wrote a part for her: Lucy, the extremely introverted woman Raj briefly dates.

"Soft Kitty" might have been stolen

Co-creator Bill Prady says he heard Sheldon's special calm-down song being sung at his daughter's preschool. Assuming it was in the public domain, he added it to the show, where it's been used multiple times and on scores of Big Bang merchandise. In 2015, however, the family of a New Hampshire teacher named Edith Newlin sued CBS and Bill Prady Productions for copyright infringement, alleging they lifted lyrics from Newlin's 1937 song "Warm Kitty." The main difference: The 1937 song begins, "Warm kitty, soft kitty, little ball of fur." The Big Bang version starts out, "Soft kitty, warm kitty, little ball of fur."

Why Howard and Bernadette's baby may never be seen again

In the middle of the tenth season, a new character joined The Big Bang Theory: Halley, the newborn baby daughter of Howard and Bernadette. And while Howard and Bernadette's lives have been radically altered by starting a family, the baby itself doesn't show up on screen too much, if at all. Showrunner Steve Molaro says that Halley will only ever be heard, screaming and crying offscreen. It's a tribute to Carol Ann Susi, the unseen actress who played Howard's similarly always-screaming mother. Susi died in 2014, and her character subsequently did, too. Molaro adds that "it also means we don't have to have a baby on set, so it solved lots of problems."

There's been a lawsuit over the theme song

Canadian pop-rock band Barenaked Ladies is responsible for "The Big Bang Theory Theme," which generates revenue for the band every time it's played on an episode of The Big Bang Theory, which is quite often. The band has even recorded an extended version of it and included it on the band's greatest hits album. The catchy number has since made its way into the band's set list when they play live. But it's all not without controversy. Although longtime Barenaked Ladies member Steven Page left the band in 2009, he says he was promised a 20 percent cut of any profits the song generated. According to Page, he hasn't seen a dime of Big Bang theme song money. He filed suit, alleging that front man Ed Robertson has kept all the money for himself. According to legal documents, Page believes he's owed somewhere in the neighborhood of $1 million.

It generated a spin-off

Almost every successful sitcom has launched a spinoff or two. Cheers led to Frasier, Happy Days spawned Laverne & Shirley, and soon The Big Bang Theory will get one, too. CBS ordered Young Sheldon, a comedy that focuses on prickly genius Sheldon Cooper, back when he was a prickly child genius living in Texas. Iain Armitage (Big Little Lies) stars as young Sheldon, while adult Sheldon's portrayer, Jim Parsons, narrates episodes. Unlike The Big Bang Theory's multi-camera, laugh track-laden setup, Young Sheldon is a single-camera, laugh track-free show, akin to Modern Family or Scrubs.

How Kaley Cuoco and Jim Parsons met

While some cast members knew each other before The Big Bang Theory was a going concern (for example, Johnny Galecki and recurring guest star Sara Gilbert worked on Roseanne together), Jim Parsons and Kaley Cuoco did not. They first met while auditioning for the show at the same time. Cuoco introduced herself, but Parsons was busy, trying to figure out how to work his new Blackberry device. Cuoco says she remembers thinking Parsons would make a "hilarious Sheldon," although it's amusingly ironic that the man who would soon play a brilliant scientist couldn't get a simple consumer gadget to function.

One actor hasn't seen much of the show

Mayim Bialik joined the series as neuroscientist Amy Farrah Fowler in Season 3 and very slowly became a love interest for Sheldon. Bialik went in to the show cold—totally cold. "I had never seen The Big Bang Theory. I knew it was a big deal because my manager told me like try and get this part," Bialik said. She still hasn't seen the Big Bang episodes produced before she joined, not to mention many of the ones that she's actually in. "I don't have TV, so I don't really watch," Bialik said.

Jim Parsons thought the show was created by a game show host

For all of Chuck Lorre's success as a TV creator and producer, Jim Parsons had never heard of him when he was about to audition for The Big Bang Theory. Parsons said on The Late Show with David Letterman that when his agent called him to say he'd landed an audition for the new "Chuck Lorre show," Parsons got confused and thought the agent meant Chuck Woolery, the host of game shows like Scrabble and Love Connection. That made Parsons less than enthusiastic about the audition. "I thought, why are they so excited about it? We should see what the man has to offer before we're like, 'It's a new Chuck Woolery pilot!'"

The unauthorized, unofficial remake of the show in Belarus

Every episode of The Big Bang Theory ends with a "title card" from Chuck Lorre. He writes a new one each time, and while it only appears on screen for a second or two, he uses it as a sounding board. In 2010, one such card reported on Lorre's discovery of a TV show from the Eastern European nation of Belarus called The Theorists. The premise, according to Lorre's title card: "a sitcom about four nerdy scientists who live next door to a beautiful blonde waitress. The characters are named Sheldon, Leo, Hovard, Raj, and Natasha." The opening sequence for the show: "a rapid-fire montage of images which takes us from the dawn of time to the present moment." Lorre was convinced that The Theorists was majorly cribbing from The Big Bang Theory, including the fact that "each episode appears to be a Russian translation of a Big Bang Theory episode." Lawyers at Warner Bros. Television told Lorre there was little that could be done because the production company responsible for The Theorists was owned by the Belarusian government. (The show was canceled before long anyway.)

There's a species of jellyfish named after the show

In 2011, a photographer named Denis Riek spotted a tiny organism in the Brunswick River in the Australian state of New South Wales. Riek knew it was a jellyfish but couldn't readily identify it, so he sent his photos to jellyfish expert Dr. Lisa-ann Gershwin. After two years of research, Gershwin and her colleague, taxonomist Peter Davie, confirmed that the 15-millimeter creature was a previously undiscovered jellyfish. As one of the discoverers, Gershwin got to help name the species, and she went with Bazinga rieki. The first part of the name refers to Sheldon Cooper's catchphrase cry of triumph, "Bazinga!"–not unlike that of a scientist shouting "Eureka!" at a moment of great discovery. But Dr. Gershwin says it also refers to a musical instrument. "The name bazinga also refers to a seven-string harp, and the straight radial canals of this new species are reminiscent of such strings." (Bazinga!)

There's a species of bee named after the show

Biologists from the Universidade Federal de Uberlandia in Brazil announced the discovery of a new bee in 2013: the orchid bee. It so closely resembles another species of bee, the Euglossa ignita that the researchers decided to give the orchid bee an official scientific name of Euglossa bazinga. Sheldon most often uses "Bazinga!" as a kind of "gotcha!" when he tricks someone or plays a prank on them. The biologists thought the word was a perfect way to describe such a tricky bee. The Big Bang Theory's showrunner Steven Molaro released a statement in response, saying that "Sheldon would be honored to know that Euglossa bazinga was inspired by him. In fact, after Mothra and griffins, bees are his third-favorite flying creatures." (Bazinga!)