In its 12-year run, The Big Bang Theory spoke to an audience who adored its humor and light-hearted nature. They also connected to the characters and identified with them. Those who felt like societal outcasts had a whole group of fictional characters they could see themselves in.

This was definitely the case with one famous guest star, of which the show had many. Even though he only made one brief cameo, he frequently visited the set many times after that.

This guest star would also reveal how his love for the show even moved him to tears.

Uranium Was Once Discovered By A Scientist On 'The Big Bang Theory' Set

There have been many unusual occurrences during episodes of The Big Bang Theory. However, one of the most unusual occurrences happened when the cameras weren't rolling.

A famous physicist once visited the set and took a look around. It wasn't long before the physicist noticed something strange.

"One day this super famous physicist was visiting," co-creator Bill Prady told Entertainment Weekly. "We're doing the set tour we always give after taping because everyone wants to get their picture taken in Sheldon's spot."

As the physicist made their way though the set, he noticed the Geiger counter, which is used to detect radiation.

Prady continued, "People always ask what that thing on the wall post was, it was this wooden box that was actually an antique Geiger counter. The physicist looks at it and goes, 'That's an old Geiger counter.'"

The physicist soon explained that the counter was more than just a prop.

"'You know,'" Prady recalled the physicist saying, "'those old Geiger counters often had a piece of uranium in them which was used to calibrate them, before people realized that's a stupid idea. I wonder if there's uranium in that.

'"

The physicist happened to have a working Geiger counter in the trunk of his car.

"He went out and grabbed it," Prady said, "and came back in with it, and brought it over to the set and, of course, the thing starts going off and making noises. He opened [the prop] up and said, 'I'm going to put this in a lead box and take it away now,' and then he removed a piece of uranium from the Geiger counter and left!"

"It's sorta like a class-action suit waiting to happen," co-creator Chuck Lorre said laughing. "I can see some law firm with a commercial on CNN saying 'Were you or a loved one ever on the set of The Big Bang Theory?'"

Steve Wozniak Made A Guest Appearance In An Episode Of 'The Big Bang Theory'

Apple co-founder Steve Wozniak appeared in the second episode of season four titled "The Cruciferous Vegetable Amplification." In the episode, which aired in 2010, Wozniak is discovered by Sheldon while dining at The Cheesecake Factory. Sheldon is appearing virtually via his Shelbot device.

Sheldon approaches Wozniak and tells him he is his 15th favorite technological visionary. Wozniak compliments Sheldon's virtual presence device and then jokes about Steve Jobs' turtlenecks.

"I fell in love with The Big Bang Theory," Wozniak said at NCR Synergy in 2013.

"It's all about how I grew up, too. Very much a nerd, very much unable to converse with people in a normal sense. It was really nice to go down there and meet the cast."

That same year, Wozniak would go on to tell Vulture that not only was he a fan, but the show actually moved him to tears.

"I really, totally empathize with all the [characters] that have relationship problems," he said, "because I was there at a part in my life, and I still don't really know how to talk to people. When I hear them talking normal small talk in parties, I don't know what to say."

At the time, Wozniak said he watched the first six seasons of the show twice and took notes on his second viewing.

"There are parts where I cry—all that relationship stuff. I can't wait to see season seven."

Wozniak revealed that it doesn't take much to make him cry and he is actually quite comfortable with it.

"I cry at movies real easy, real easy. I cry at almost every movie we go to. I cry over the fact that somebody could make something so beautiful."

Steve Wozniak Would Make Frequent Visits To 'The Big Bang Theory' Set After His Appearance

Throughout the 12-year run of The Big Bang Theory, there were many memorable guest stars who made appearances. Prady and Lorre reflected on those appearances when speaking to Entertainment Weekly.

The two were being interviewed to celebrate the show's 15th anniversary.

"Throughout the show's run, really famous scientists visited the set all the time," Prady said. "We had Nobel laureates and astronauts, we even had tech guys and corporate titans like Bill Gates and Steve Wozniak."

It turns out that Wozniak's love for the show was so strong, he stopped by even after filming his cameo appearance.

"Steve actually came back and visited like five more times after he filmed his episode," Lorre said.

"He'd come by and just hang out."

Lorre concluded the Entertainment Weekly interview by validating the message of The Big Bang Theory that resonated so strongly with Wozniak.

"We connected with a lot of people who felt alienated, the same way these characters did," Lorre said. "They wanted to be a part of life, but they didn't know how. And these characters said, here's how — you create your own community and your own family. They showed the world that nobody has to be alone."