If you continue this way, I may actually begin to get a hang of this aerodynamics thing and why it is more difficult for planes to take off in less dense air. If I'm right, the reason is literally because the air has less "weight" to help and carry the plane as it attempts to rise from the runway, therefore more runway distance is required to enable the plane to gain enough momentum to lift off, right?

Well, as for the circular runways, I suppose if the calculations say it is feasible, one of these days, we might find other reasons why we would need to explore that option. Necessity, they say, is the mother of invention.

This is pretty cool.