Did you watch "A Night With The Stars" on BBC2 last night?
Professor Brian Cox lectured a celebrity audience about some of the most challenging concepts in physics from the lecture theatre of the Royal Institution of Great Britain.
Here's a clip from the show:
The comedian Simon Pegg and physicist Jim Al-Khalili help him explain standing waves in a demonstration to show why atoms are so large and empty.
It was a brilliant show! If you missed it, be sure to catch in on iPlayer.