It's been almost 2 years since the last episode of The Big Bang Theory aired. One of the longest running sitcoms in the history of television, the show has been an absolute favourite.

Having grown up with the show, it has a special place in my heart. It's one of those feel-good shows that can be watched anytime, anywhere. Over the years, the cast and crew of the show revealed some behind-the-scenes facts that are not known to many. Here's a few of them.

1. Mayim Bialik, who plays Amy Farrah Fowler in the show, holds a PhD in neuroscience in real life.

She is the only cast member with a scientific background. In an interview with Variety, Mayim once said:

They didn’t have a profession for my character when I came on in the finale of season three. In season four, Bill Prady said they’d make her what I am so I could fix things (in the script) if they were wrong. It’s neat to know what things mean. But most of the time, I don’t have to use it.

2. Jim Parsons, who played Sheldon, has never seen a single episode of Star Trek in real life.

Sheldon is a huge fan of Star Trek in the show. But it's kind of unbelievable that he has never seen Star Trek. In an interview with Time, he said:

I’m very frank about certain things, I get asked a lot of science things and I’m like, ‘You’re kidding’. And even the pop culture… I’ve never seen Star Trek. I don’t know Doctor Who.
Source: Hollywood Reporter

3. Wil Wheaton, who plays Evil Wil Wheaton on the show, got the gig through Twitter.

He once tweeted about how much he loved the show and laughed at its jokes. Executive producer of the show Steven Molaro noticed the tweet and invited him for taping. A few days later, he was asked if he wanted to be on the show.

Source: mentalfloss

4. There are a species of bee and jelly fish named after Sheldon's favourite word 'Bazinga'.

The jelly fish was first sighted in Australia’s Brunswick River in 2011. Discovered in 2013 in Brazil, the bee species was named Euglossa Bazinga.

5. 'Soft Kitty' is an actual song.

The song never gets out of your head. It dates back to the 1930s and producer Bill Prady revealed that his daughter sang 'Soft Kitty' at pre-school.

The original song was: Warm kitty, soft kitty, little ball of fur, Happy kitty, sleepy kitty, purr! purr! purr! A little different than what's shown in the series.

Source: nytimes

6. Jim Parsons did not know Chuck Lorre when he went to audition for the show. He thought it was going to be a game show.

In an interview with David Letterman in 2014, Parsons said:

I did not know Chuck Lorre at the time. I thought he was talking about Chuck Woolery. 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!'
Source: beyondthemarquee

7. The cast actually ate all the food their characters were shown nibbling on in the living room.

Remember all those scenes where you see everyone in Sheldon and Leonard's living room with fancy takeaway boxes? The cast apparently ate all that food on the sets.

Source: Metro

8. At one point, the original cast of the show apparently earned $1 million per episode.

By the time the show entered its 10th season, Jim Parsons, Johnny Galecki, Kaley Cuoco, Kunal Nayyar and Simon Helberg earned as much as $1 million per episode. They were among the highest paid TV actors that time.

Source: Today

9. A real-life professor, David Saltzberg, was behind the science in the show as a science consultant.

Saltzberg studies high-energy particle physics and high-energy neutrino astronomy, using radio-detection techniques. He attended the show's live taping at the Warner Bros. and made sure the whiteboards were correct.

Source: wsj

10. There was only one staircase on the set.

All those years I spent watching the show felt like a lie when I got to know that there was just one set of stairs on the show. The 'out of order' lift makes so much sense now.

11. Leonard’s glasses didn't have any lenses.

Damn. Even Leonard is not what he seems. In conversation with HuffPost, Johnny Galecki revealed the truth behind his glasses and explained that he usually had to look up when talking to Jim Parsons, and when he did that, his lenses caught the light. This is when he popped out the lenses and it's been that way ever since.

12. There's an unaired pilot episode of the show with an entirely different cast.

This pilot had the same Leonard and Sheldon but Wolowitz and Koothrappali didn’t exist, while Penny and Leslie Winkle’s parts were portrayed by other actresses.

How many of these did you know?