In these uncertain times, it's comforting to know spinoffs aren't going away any time soon - especially when it involves television's most-loved theoretical physicist.

Big Bang Theory fans sat upright last year when it was revealed the unsociable but quirky scientist Dr Sheldon Cooper would have his own origin story.

Now, actor Jim Parsons has shed more light on the TV spinoff, saying it will be "very different" from the show that made his character a household name.

Parsons told Entertainment Tonight there will be plenty of material for screenwriters to work with, especially given Big Bang's creators have done "such a good job" with his character's history and background.