Tks for the information, Raddy and gratefulmom. Michio Kaku! Why didn't I think of that?

We've been experimenting with the cable channels in the past one week but the adverts are way too difficult for DS to take, so BBC Knowledge (minimal adverts) and Youtube's the way to go for us. In addition, I found this blogspot with a tonne of recommendations for great documentaries:

http://bookslinksandmore.blogspot.com/2010/07/thought-provoking-documentaries.html

The rest of the blog is amazing too, so do have a look.

Cheers!