It’s not a natural way of… of looking at the world, although it comes… it can be learnt and it springs from our curiosity and it has lead to this great expansion of our knowledge in space and time. And also we have to think of ordinary things like causality possibly being different and much more subtle things than we’ve touched on so far. Well, for example, we know that space and time are not as distinct as I just implied in the thing; that… that relativity shows, essentially, they're one aspect of space time but you don’t discover that until you get up to velocities which are comparable to the velocity of light, roughly speaking. And… that’s not, again, something which we normally experience in everyday life, except light and we don’t even know how fast that’s moving. I mean, if you ask the average person how light moves, they’ll just say very fast but they really don’t know.

[Q] So fast….

They might know how fast sound moves because they’ve heard a thunder… a clap of… of thunder following the flash but, they have very little idea of… unless they’ve learnt it from books, of how fast light moves.