This post has already been read 873 times!

The celestial sphere is an imaginary sphere of arbitrary radius on the surface of all the stars are projected. The celestial sphere is said geocentric, if you have to center the center of the earth, local, if the observer’s eye to the center, heliocentric, if you have to center the sun. The origin of such arbitrariness of the radius lies in the fact that beyond a certain distance we are no longer able to visually evaluate the distance of the bodies, for which the stars appear to us all at the same distance. During the apparent diurnal motion of the two stars only points of the sky, antipodal to one another, remain motionless: these are the celestial poles. The celestial sphere seems then rotate on itself around an axis passing through the poles, called celestial axis. Since the visible stars and their positions in the sky vary with the position of the observer on Earth, it is useful to use as references the vertical of the place and the astronomical observer horizon plane. The concept of “celestial sphere” dates back to ancient Ptolemaic system, prior to the Copernican revolution, in which it was believed that the stars and planets were really set on similar orbits to spheres of different sizes, located one inside the other and having as center of the Earth. The motion of celestial bodies such as the Sun or the Moon was due to the rotational movement of these balls, which move dragged them with him. It was in any case transparent and invisible spheres, composed of ethereal substance, that is, of a crystalline element of spiritual nature, not present in the world sublunar terrestrial. Pythagoras could see in them the mathematical relationships that produced the celestial harmony, the so-called “music of the spheres”, inaudible to the human ear, able to affect the quality of life on earth. Hence the symbiosis with the study of archeology.

 

To open the video click on the image, good view from your Alessandro Brizzi.