Quote Originally Posted by joecoolfreak
A planes engine does not provide thrust to the wheels. That is why the examples prove the point. Look at the skateboard example again. Turn the treadmill on to full blast and use your hand to hold the skateboard steady. You barely have to hold on to keep it in place, now push forward. That is what the engines do in a plane and you will see that the skateboard now moves forward...hence our movement and then you have lift.

ok, so then i am on this treadmill on a skateboard, now if I need to get up to 100mph (that means actually moving forward, not sitting in one place) on my skateboard, having a treadmill under me will do nothing for me, if not impede me. The theory is still flawed. If a plane needs to travel 500mph (not sure how fast it has to go, just using a random number) to take off, and if it is sitting on this threadmill, and the jets produces enough thrust to propel the plane at 500mph, but ther ground underneath the plane is moving in reverse direction at 500mph, then the plane, technically, is not moving. And if the plane is not moving, there is no air traveling over and under the wings, which is needed for lift. So since there is no air traveling over and under the wings, there is no lift.



Here, do this. take a piece of paper, tape two ends together, stick a pencil through the open end. now hold the pencil parallel to the ground, and blow over the paper. the paper rises because the air pressure over the paper was less than what was under it. now put wheels on each end of the pencil, tie the pencil to the front end of the treadmill, and turn the treadmill on. I will garuntee that the paper will only drag against the treadmill.