> Why on earth would someone not call the first airplanes an earlier form of the Boeing 747? Because you need to draw the line somewhere reasonable. Otherwise

> Why on earth would someone not call the first airplanes an earlier form of the Boeing 747? Because you need to draw the line somewhere reasonable. Otherwise, why don't we take your logic one step further and say an aluminum sheet is an earlier form of the Boeing 747 ? The difference between the Wright Brother's plane and a Boeing 747 is simply too enormous to be a logical "earlier form". The only thing the two share are the fundamental physics of aerodynamics. And even then, we are only talking the sort of shared aerodynamics you'll learn about at an aerospace museum on a school trip when you get to put a piece of cardboard in a wind tunnel. Its a bit like saying a donkey is an earlier form of a car. Well, sure, people used to use donkeys extensively for transport. But I think most people would agree calling it an earlier form of a car is pushing it.