Why Do Planes Fly? What we sometimes see in science is that a theory is used to explain some phenomena which on the surface at least seems to work. But upon closer examination we find that something else entirely is happening, and it turns out to be mere coincidence that the theory seems to explain the phenomenon. The lift produced by the wings of birds and airplanes is currently understood in the context of a 17th century physicist named Daniel Bernoulli, whose explorations of static and dynamic gas pressures seem to explain how lift occurs. While I have no problem with Bernoulli and his theory, the theory's apparent relationship to lift on an airplane wing is purely coincidental. A wing generates the force of lift for entirely different reasons. To understand lift I propose you perform the following experiment(s), which will require only the use of your imagination. Start of by firing a gun directly into a brick wall, so the bullet strikes the wall at 90 degrees, and measure the amount of force of the bullet. We'll call that force P. Now fire the gun into the wall at forty five degrees, so the bullet hits the wall at a glancing angle. The bullet which hits the wall at 45 degrees will exert a force of 1/2 P. Now you're in your pickup truck, driving along parallel to the wall at a very high rate of speed. You lean out the window and fire at the wall again. The combined forward motions of the truck and bullet result in another bullet striking the wall at an angle. 1/2 P again, even though you aimed the gun 90 degrees to the target. This is what happens on the surface of a wing to create the force of lift. Instead of bullets, you have air molecules which are striking the wing in a series of elastic collisions at an infinite number of angles. When air moves over the wing, or the wing moves through the air, these angles flatten out and become more oblique. Like the bullet fired from the moving truck, they exert less pressure on the wing surface. This also explains why an airplane wing doesn't create lift in a smooth progression. You don't keep getting more lift the faster you go because the angles are flattening out, becoming more oblique up to a point, then increasing airspeed results in fairly minor increases in lift. And thus we see that the force of lift *is* created by air movement in relation to the wing surface. And it has nothing to do with Bernoulli and his theories of fluid dynamics...
[Submitter's (to alt.humor) note: This article is only really funny if you are a scientist. The author dismisses as irrelevant the theory underlying the design every aeroplane in existence. He manages, in a few short paragraphs, to demonstrate a quite staggering density of misconception, throwing in a few nonsensical and erron- eous calculations for good measure.
A New Theory Of Lift, tsimonds@world.std.com (Tom Simonds), sci.aeronautics © Tom Simonds 1996.