Theme from an eighties movie called "Biggles: Adventure in Time" which is loosely based off the much older books. The main character, Biggles, is a WWI fighter pilot. EDIT: Yeah, did I mention it was from the '80s, or what?
"You see what your knowledge tells you you're seeing. ... how, what you think the universe is, and how you react to that in everything you do, depends on what you know. And when that knowledge changes, for you, the universe changes. And that is as true for the whole of society as that is for the individual. We all are what we know, today. What we knew yesterday, was different; and so were we."
- James Burke, The Day the Universe Changed (1985)