I was late to the Airplane on a Treadmill party, so maybe you were too. Not since the famous Monty Hall and the Goat problem has so much hot air been generated by an online puzzler. Stated briefly, here is the problem:
Imagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway. The conveyer belt is designed to exactly match the speed of the wheels, moving in the opposite direction. Can the plane take off?
What’s your answer? I must confess that I was seduced by the wrong conclusion for a while. This problem has now been around so long that the Myth Buster guys have had the time to demonstrate it on TV. Even if you have been aware of this problem for a few years, I recommend the writeup on the eponymous airplaneonatreadmill.com site entitled Airplane on a Treadmill Definitive Analysis. It’s a nice piece of writing about physics, and it does what so much of good science writing does: reframe the question using clearer terminology. In particular, look at his rewording of the problem into three separate but related problems.
Simply put, cars grab onto the ground to pull themselves forward. If you move the ground, they can’t go anywhere. Planes, in contrast, grab onto the air to pull themselves forward. If you move the ground, they really don’t care so much.