seemingly solved many astronomical problems with a simplicity and a harmony utterly lacking in the old traditional scheme. Unaided by a telescope, he worked out in part the right theory of the universe and for the first time in history placed all the then known planets in their true positions with the sun at the center. He claimed that the earth turns on its axis as it travels around the sun, and careens slowly as it goes, thus by these three motions explaining many of the apparent movements of the sun and the planets. He retained,[1] however, the immobile heaven of the fixed stars (though vastly farther off in order to account for the non-observance of any stellar parallax[2]), the "perfect" and therefore circular orbits of the planets, certain of the old eccentrics, and 34 new epicycles in place of all the old ones which he had cast aside.[3] He accepted the false notion of trepidation enunciated by the Arabs in the 9th century and later overthrown by Tycho Brahe.[4] His calculations were weak.[5] But his great book is a sane and modern work in an age of astrology and superstition.[6] His theory is a triumph of reason and imagination and with its almost complete independence of authority is perhaps as original a work as an human being may be expected to produce.
Copernicus was extremely reluctant to publish his book because of the misunderstandings and malicious attacks it would unquestionably arouse.[7] Possibly, too, he was thinking of the hostility already existing between himself and his Bishop, Dantiscus,[8] whim he did not wish to antagonize further. But his
- ↑ Delambre: Astr. Mod. pp. xi-xii.
- ↑ As the earth moves, the position in the heavens of a fixed star seen from the earth should differ slightly from its position observed six months later when the earth is on the opposite side of its orbit. The distance to the fixed stars is so vast, however, that this final proof of the earth's motion was not attained till 1838 when Bessel (1784-1846) observed stellar parallax from Königsberg. Berry: 123-24.
- ↑ Commentariolus in Prowe: III, 202.
- ↑ Holden in Pop. Sci., 117.
- ↑ Delambre: Astr. Mod., p. xi.
- ↑ Snyder: 165.
- ↑ Copernicus: Dedication, 3.
- ↑ Prowe: II, 362-7.
