RE: Why do people say the top of the wing causes the plane to fly?
Excellent picture, Evan!
I believe those particular air conditions made its temperature be very close to the dew point.
The moving wing reduces the pressure of the air above itself (the mass of air expands), reducing its temperature enough to produce dew or mist.
The moving wing increases the pressure of the air below itself (the mass of air compresses), increasing its temperature farer away from the dew point, so mist is not seen below the wing.
The drag produced by the pressure differential can be seen in the formation of vortex at the wing and tail tips, and more strongly at the gap where the flaps and the ailerons meet at different angles (a rough transition induces more turbulence and friction than at the tips).
This drag is attached to finite wings, for which always high pressure air will find a path to flow to low pressure air.
The slower the flight velocity, the higher the CL and pressure differential most be, the more energy in vortex will be wasted.
…….And yes, a 150 tons jet does not float in the air by just moving 15 pounds of air; as you wrote, it must “move a heck of a lot of air a pretty long way”.
Mass of airplane x Velocity of airplane = Mass of disturbed air x Velocity of disturbed air (by wings and engines) = Work or energy transferred from the engines to the atmosphere to keep that monster afloat for many miles.
Regards!!