Bob Cook wrote:
Gravity is a downward force. Things move downward due to gravity,
including gliders.

Aren't there some things that move upward due to gravity? Even upward and
sideways too?

But the question was not "what gives a glider motion?", it was "what
gives a glider FORWARD motion?"

Sorry, can't do it without LIFT. (don't forget drag either)

Three forces act on a glider. Not one, not two, THREE.

But isn't there only one potential energy field operative? Not two, or
three, just one? Didn't Aharonov and Bohm show that potentials are more
"fundamental" than forces, so that we should really be considering the
system using potentials?

Is somebody keeping score on the pedantry? I hope I got at least a couple
points!