- sky -

The sky is the part of the atmosphere or of outer space visible from the surface of any astronomical object. It is difficult to define precisely for several reasons. Have you wonder why the sky is in blue? During daylight, the sky of Earth has the appearance of a deep blue surface because of the air's scattering of sunlight.
The intricate traceries in the sky are, no doubt, the loveliest and most perfect of material things, but still part of the visible world, and therefore they fall far short of the true realities. the real relative velocities, in the world of pure number and all perfect geometrical figures, of the movements which carry round the bodies involved in them. These, you will agree, can be conceived by reason and thought, not seen by the eye... If we mean, then, to turn the soul's native intelligence to its proper use by a genuine study of astronomy, we shall proceed, as we do in geometry, by means of problems, and leave the starry heavens alone...

p/s :

As flyers, we always pray for clear sky, no significant weather. But the sky is unpredictable. It can change in seconds. What human merely can do is just, anticipate the changes, foresee it and PRAY.

* we always pray *

-[d]rew-