Sixty Symbols is a growing collection of video conversations made by expert scientists at The University of Nottingham. Each video conversation features a symbol (real or fictitious) in physics or astronomy. Sixty Symbols describes itself below:

They aren’t lessons or lectures – and this site has never tried to be an online reference book. The films are just fun chats with men and women who love their subject and know a lot about it!

You can see the videos on the Sixty Symbols site and also on the Sixty Symbols YouTube Channel.

See the example of the Density Video embedded below: