crossing and uncrossing..

Diverging and intersecting lines mark the paths of jets high, high in the sky.. They streak through the thin atmosphere, coming here and going there. Separated by time, mostly.. The trails start off sharp and clear, but soon become blurred and wavy as the winds tug at them until they are utterly erased.

 

Seen from below, they can seem laser straight, but in reality, they are never straight. They follow the curvature of the earth as they maintain their assigned altitudes.. Bowed like the arching flight of an arrow from one destination to the other..

Done