Airplane Mechanics Help Please!!! Okay so I have a question about lift. I've heard different explanations of lift from various sources. I first thought that the SHAPE of an airplane wing was the reason that lift occured. I was taught that since the surface area on the top of the wing is larger than the surface area on the bottom, the wind on the top of the wing is moving faster than the wind on the bottom of the wing to cover a larger distance over the same amount of time. Because the wind above the wing is moving faster, the molecules occuring to the top surface of the wing are more spread out compared to the molecules occuring to the bottom surface of the wing, thus the pressure of fast wind on top is less than the pressure of slower wind on bottom. Then the wind with higher pressure on the bottom would push towards the wind of lower pressure on the top, creating the force, lift. Then I was told something else. I was recently informed that one can make an airplane with flat boards of wood for wings. I questioned how this was when the air traveled the same distance over the same amount of time both over and under the wing. The person replied that when the board is placed at an angle and moved forward through the air as to direct the air downwards with its slope in horizontal flight, the wind that would have been above and behind the board is pushed down below and in front of it and a vaccuum is left behind in the board's wake where the wind would have been had it not been directed downwards by the angle of the board, causing the pressure of the air beneath the board to push towards the vacuum. For example, a flat board moved through air at a 90 degree angle to its motion would have a vacuum wake following immediately afterwards as the air scrambles to refill the place that the board just was. I mean of course in an airplane you wouldn't have a wing fly 90 degrees to (flat against) its motion. I'm just exaggerating the effect of tilting the board by showing what happens in an extreme circumstance. My question is this: is there any validity to the first explanation of lift, and if not, why is nasa teaching this explanation? Both make sense to me and I'd really like to know the real definition. If the first explanation does hold truth, then couldn't you just take a board, and, like blowing over a piece of paper to make it rise, attach large enough fans to its top and blow the air across its surface to make the air above the board less dense so the pressure from the bottom would push it up?