"I wish that I could fly, into the sky, so very high, just like a dragonfly. I'd fly above the trees, over the seas, in all degrees, to anywhere I please."

-Lenny Kravitz, American singer & songwriter, born 1964.

These lyrics are from the 1998 song Fly Away by Lenny Kravitz. He’s describing the freedom associated with flight, and he’s lists a few things he’d do if he could fly. These are timeless ideas, and they tie in closely with the history of flight. The first thing he mentions is flying into the sky. The sky represents a place that we humans are unable to reach while we’re on the surface, so this gets to the core of the human need for verticality. Next, he mentions the trees and the seas. These are elements that ground-dwelling creatures must navigate in order to travel across the surface, but with the ability to fly, we can traverse these landscapes with ease. Lastly, he mentions traveling in all degrees. For the most part, traveling across the surface is based on two dimensions of movement: forward/backward and left/right. When in flight, you add a third dimension to these two: the up/down. These can also be expressed as the x, y, and z dimensions of cartesian space, respectively. This third dimension results in much more freedom of movement, which is what Kravitz is referring to.