— James Burke (science historian) British broadcaster, science historian, author, and television producer 1936
Context: An invention acts rather like a trigger, because, once it's there, it changes the way things are, and that change stimulates the production of another invention, which in turn, causes change, and so on. Why those inventions happened, between 6,000 years ago and now, where they happened and when they happened, is a fascinating blend of accident, genius, craftsmanship, geography, religion, war, money, ambition... Above all, at some point, everybody is involved in the business of change, not just the so-called "great men." Given what they knew at the time, and a moderate amount of what's up here [pointing to head], I hope to show you that you or I could have done just what they did, or come close to it, because at no time did an invention come out of thin air into somebody's head, [snaps fingers] like that. You just had to put a number of bits and pieces, that were already there, together in the right way.