Gök ve Onun Adı Üzerine

On the sky and its name. Philosophers have said the sky is round, revolving, and burning. It is called by this name because, like a caelatum (engraved/chased) vessel, it bears the impressed signs of the stars. For God distinguished it with bright lights and filled it, that is, with the sun and the glowing orb of the moon, and adorned it with the shining signs of twinkling stars. This is called in Greek ouranos (sky/heaven) from horasthai (to be seen), that is, from seeing, because the air is clear and purer for gazing. On the position of the celestial sphere. The sphere of the sky is a kind of form shaped into a roundness, of which the earth is the center, enclosed equally from all sides. They say this sphere has neither beginning nor end, because, being round like a circle, where it begins or where it ends is not easily grasped. Philosophers have introduced seven skies of the world, that is, the planets, with a harmonious motion of the globes, to whose orbs they mention all things are connected. They believe these are linked together and, as if inserted, turn backwards and are carried in motion opposite to the rest. On the motion of the same sphere. The motion of the sphere revolves on two axes, one of which is the northern, which never sets and is called the Boreus (Northern/Boreal); the other is the Southern, which is never seen and is called the Austronotius (Southern/Austral). They say the sphere of the sky moves on these two poles, and with its motion, the stars fixed in it circle from the east to the west, with those in the north performing shorter revolutions near the pivot.