@divegeester
I don't know how you would prove it either way. If there were sensors light enough say the weight of a postage stamp and able to transmit data above and below the wing it might give a readout showing less pressure on top which is the only way there can be lift but the best paper planes gain altitude and you don't get that just gliding.
They main way paper planes get altitude is by extra control surfaces like elevators/flaps on the trailing edge.
If the paper is folded so it is at least double thickness, you can attempt an airfoil shape, but without a more constant thrust (not just the intial throw) the airfoil won't be as effective.
@divegeester
If there was no lift a paper airplane could not even fly in a straight line much less gain altitude.
If there was no lift the flight path would just be an angle aiming at the ground but the best of them are gliding some two hundred FEET. You can never get a paper airplane with zero lift to fly that far.
Did you even look at the link I provided, the king of paper airplanes?
@divegeester
It is the Paper airplane expert, he really knows his stuff. And he broke the world record for distance, 200 feet for a paper airplane. You should watch it, he gives examples of how to make various planes all out of ordinary 8 1/2 X 11 printer paper.
He figured out how to make it look like bats wings flapping or one turning upside down and going right back at him and the like.
@divegeester
Like I said, without SOME lift going on with the wings, he never would have gotten a paper airplane to fly 200 FEET.
I would be luck to get TWENTY feet out of a paper airplane🙂
@divegeester
Like I said, without some lift, a paper airplane could never fly 200 feet, drag would pull it down long before it flew that kind of distance.
It's a matter of proof in the pudding.