In article ,
Beryl wrote:

Jim Logajan wrote:
Alan Baker wrote:
Because the push is caused by the impact of countless air molecules
with the surface of wing. If those collisions fall to zero (i.e. in a
perfect vacuum) then there is zero push.

I don't see what a change in air density (such as taking the extreme case
of a vacuum) has to do with lift.

I'm going to build a thick wing, real thick! About 10,000 feet thick.
While the bottom surface of the wing sits at 29.92" sea level
atmospheric pressure, the upper surface will be *way* up there, in a
lower-pressure area. This airplane is gonna to lift off the ground at
zero airspeed with no power.

Only if you make it from monatomic Unobtanium. Only thing light enough
for the job.