When I was very young, I attended a lecture at the Royal Institution. Well, I think I did. I seem to remember that I did, but it might be a false memory. Memory is a funny thing.
I seem to remember the lecture theater, but I can't remember what the lecture was about, which is strange, because surely I would?
Anyway, I've definitely seen RI lectures on the television, and now, thanks to the magic that is the internet, you can watch them on youtube.
I recommend them very highly. They are aimed at children, so there's lots of exciting demonstrations, but they don't talk down to you, and they're very suitable for adults too.
I've been watching several of them. Recommended. And show your children.