home *** CD-ROM | disk | FTP | other *** search
- COPERNICUS REVOLUTION: 1473-1543 A.D.
-
- Copernicus radically altered the accepted Earth
- centered model of the universe.
- Dismissing Ptolemy's elaborate model of equants
- (which compromised the principle of uniform circular
- motions), Copernicus chose a different model: he
- placed not the Earth but the Sun at the center of
- the universe. He put forth his theory in his "On the
- Revolutions of the Heavenly Spheres" in 1543.
- Copernicus correctly deduced that the Earth
- rotates daily on its axis and orbits the sun every
- year. Moreover, he proposed that the planets also
- orbit the sun and that the earth wobbles like a top
- (precesses on its axis) as it rotates. This theory
- explained the retrograde motion of Mars and why the
- planets Mercury and Venus never stray far from the
- Sun in the sky.