I am told that airplanes (the regular commercial ones) can take off from the ground without displacing itself. In other words, runways dont have to be as long as they are today, just 2–3 times their nose-tail length would be good. I dont know if this true, but if it is true airports like Sau Paulo in Brazil could benefit

How does it work?

The most compelling theory I have heard is this — planed dont cruise on the runways to gain momentum. They do that merely to gain engine speed. In other words, if the plane was on ground long enough for the engines to rev to cruising speed levels, it can take off from right where it is. How is this possible? Park the aircraft on a special surface, similar to the indoor walking track in a gym where the conveyor will counter displacement created by the aircraft wheels.

Possible? I guess!?