when you're running on a treadmill, every time your foot hits the treadmill, it's pulling you back at 10mph. if you were wearing rollerblades instead, the only affect the treadmill would have on you is the resistance of the bearings, something that you could easily overcome by lightly holding onto the rail. if you tried to hold on to the rail with your feet planted on a 10mph moving treadmill, you'd get pulled off.

there's two different types of speed in this equation. forward speed of the plane (which is relative to the earth) and the speed of this treadmill. when the experiment starts, they are both going 0. the plane is sitting on the treadmill, and the treadmill is not moving. the plane then starts to move forward at a given speed (relative to the earth, not the treadmill), and continues to gain speed like it normally would on a take off. the speed relative to the earth and the wind it needs for lift is not affected by the treadmill.

imagine if this plane had hover-jets instead of wheels, then it would take off no problem, right? because then there'd be 0 friction for the treadmill to have any affect on the plane. well the bearings and tires of the plane have only a very small amount of friction that gets placed on the plane, something that the jet can easily overcome for takeoff.

i vote we lock this thread until january 30th