It was described this way by Aristotle in his « De Cœlo ».
Four centuries later, the astronomer Claude Ptolemy, in his work “”, which took into account his measurements of the position of known planets, established Aristotle’s philosophical theory as a scientific theory.
My works cover two domains, gravity and sedimentology, for which the intellectual concepts involved – in the absence of fundamental experiments – could lead to erroneous deductions.
In conjunction with the appropriate specialists I endeavored to conduct fundamental experiments.
In fine weather navigators far from the coast saw the sky horizontally and vertically.
They spoke of it as a « celestial vault », an apparent sphere which, on a clear night, moved together « carrying » the stars with it.
Set out below are details, results and conclusions.
In terms of astronomy, the original concept of the universe was based upon appearances.
In the third century before Christ, however, Aristarchus of Samos, espousing the existence of the fixed star sphere, postulated that the Sun was its centre.
From his calculations of their approximate distance from the Sun, he assigned them a circular orbit, which Kepler demonstrated soon after to be an ellipse, with the Sun as one focus.