The Fatal Consequences of a Priori in the Natural Sciences, to be Replaced by Facts

Abstract

The conception of the universe through the agesLet us first speak, in Astronomy, of the original conception of the Universe, based on appearances. Every man, sailing on the sea, far from the coast, in good weather, sees the sky horizontally, in all directions, and vertically. He speaks of "celestial vault, '' an apparent sphere on which, by clear night, moves, together with the stars "carried" by it. That was what was described by Aristotle in his "De Coelo". Four centuries later, the astronomer Claude Ptolémée, in his work "L'Almageste", reporting on measurements of the positions of known planets he had compiled, consecrated the philosophical theory of Aristotle as a scientific theory, which were taught in Christian universities in the Middle Ages. However, in the 3 rd century BC, Aristarchus of Samos, adopting also the existence of the sphere of the fixed stars, postulated that the sun was the center. There were then, in the time of Ancient Greece and Rome, two philosophical schools, which agreed on the existence of this sphere carrying the fixed stars, but opposed on which star was at the center, either the Earth or the sun. This quarrel would re-emerge in the midst of Christianity in the Middle Ages. Copernicus, canon and astronomer, wondering about the irregular orbits described by the planets around the Earth, completed the calculations of the positions of the planets of Ptolemy and "demonstrated" that they revolved around the sun; he, however, attributed to them, by his approximate calculations of their distance from the sun, circular orbits which Kepler soon showed to be ellipses whose sun was a focus. Copernicus reported his theory in the work "De Revolutionibus Orbium Caelestium", published in 1543, which was sent after his death, by his friend Osiander, to Pope Paul III.In his Preface, Copernicus, applying to the Earth the status of a planet, affirmed without proving that it revolved around the sun, and that, therefore, it was the sun that was the center of the world, quoting Trismegistus. who called the sun "visible god". Pope Paul III and his successors did not react. Tycho Brahé, astronomer of the king of Denmark, made at this time many measurements of the position and distance of the planets in the solar system, that Kepler would use and supplement by the particular study of Mars, which would lead him to formulate his three Laws in "Astronomia Nova" and "Harmonices Mundi". Tycho Brahé had just remarked that the apparent position of the sun and the planets, seen from the Earth, remained the same whether the sun revolved around the Earth or vice versa. But the temptation to consider the Earth as any other planet was too strong and Kepler adopted the Copernicus hypothesis.Then came Galileo. The latter, a teacher at the University of Padua and persuaded of his success in astronomy, affirmed himself high and strong Copernican. The Church then reacted by the decree of 1616, which condemned two Copernican propositions: a. The sun is the center of the world, and b. The Earth is not the center of the world ...