'Big Bang Theory' Stars Dish on Sheldon and Amy's Season Finale Wedding, Stephen Hawking's Death

The Big Bang Theory Sheldon Amy

The cast and creators attended a PaleyFest panel on Wednesday.

Not all the chemistry on The Big Bang Theory is the science kind! 

At Wednesday night's PaleyFest panel at the Dolby Theatre, The Big Bang Theory stars and producers dished on what fans can expect for the end of season 11, as well as reflecting on high points from the show's highly successful 11-year run. 

This season, TBBT has been building towards the wedding of Sheldon and Amy, played by Jim Parsons and Mayim Bialik respectively -- and that wedding will form the basis for the season's closing episode, with the show's creators confirming they've been "putting a lot of thought" into how the characters would want their wedding to be. 

While the details of that episode are still under wraps -- in fact, the episode has not yet been written (creator Chuck Lorre confirms it "exists as an idea") -- they did drop a few clues about what to expect. 

Laurie Metcalfe, now an Oscar-nominated actress for Lady Bird, will reprise her role as Sheldon's mother Mary, and Lorre hinted that older versions of other Young Sheldon characters, like siblings Missy and Georgie Jr., may also make an appearance. 

And in the lead-up episodes, fans can look forward to bachelor and bachelorette parties that "don't go how you think they would go," teased actress Kaley Cuoco. 

The stars also talked about the recent death of Stephen Hawking, the legendary physicist who -- among his many achievements -- appeared on several episodes of the show (in person and on the phone) in addition to being a regular topic of conversation among the science-obsessed friends.  

"He was the smartest person you’re ever going to meet," said Parsons. "What an honor to get to play these types of people all the time." 

"[Hawking] had an unbelievable presence on our show from day one," Cuoco added. "And after he passed, I was thinking about that too: he's been in the foreground of our show for a long time." 

"I found out a few seconds after the taping on Tuesday," said Kunal Nayyar, who plays Rajesh Koothrappali on the sitcom. "Maybe we were doing the last scene. And I remember feeling so incredibly sad. I was mourning like Kunal, but also mourning like Raj, if that makes any sense. His character was a presence on our show." 

While looking back over the 11 successful seasons of the CBS show, the actors also took a moment to think forward to its inevitable last episode -- leading to some emotional moments. 

"The fact that we've been able to make people laugh for this many years and have these really sweet storylines and be the family that we were...," Cuoco said, choking up as she spoke. "I already can't handle it!" 

The Big Bang Theory airs Thursdays at 8 p.m. ET on CBS.