Changes

A Polish scientist named '''Nicolaus Copernicus''' (Polish:Mikołaj Kopernik, 1473-1543) published a model of the [[solar system]] that combined the [[heliocentrism]] of [[Aristarchus]] with the epicycles of [[Ptolemy]]. "Finally we shall place the Sun himself at the center of the Universe.  All this is suggested by the systematic procession of events and the harmony of the whole Universe, if only we face the facts, as they say, 'with both eyes open.'"  

A Polish scientist named '''Nicolaus Copernicus''' (Polish:Mikołaj Kopernik, 1473-1543) published a model of the [[solar system]] that combined the [[heliocentrism]] of [[Aristarchus]] with the epicycles of [[Ptolemy]]. "Finally we shall place the Sun himself at the center of the Universe.  All this is suggested by the systematic procession of events and the harmony of the whole Universe, if only we face the facts, as they say, 'with both eyes open.'"  

Copernicus worked for years on his book describing his theory, and published it near the very end of his life.  He entitled it, "De revolutionibus orbium coelestium" ("On the Revolutions of the Heavenly Spheres"), and published it in 1543.  The major parts of Copernican theory are:

Copernicus worked for years on his book describing his theory, and published it near the very end of his life.  He entitled it, "De revolutionibus orbium coelestium" ("On the Revolutions of the Heavenly Spheres"), and published it in 1543.  The major parts of Copernican theory are:

In fact the Copernican theory was no more accurate than the Ptolemaic model. It had no compelling physical arguments for its superiority, and it proposed no experiments for testing its novel features. In some respects, it was actually less accurate, as more epicycles had to be added (in place of Ptolemy's [[equant]]).  Copernicus' main argument in favor of his theory was that it was aesthetically more pleasing as it allowed the planets to move in uniform circular motion, an idea later proven false by Kepler.  Many of the ancient Greek arguments for and against [[heliocentrism]] remained unresolved for some time. <ref>Ancient Greeks objected to Aristarchus's heliocentrim because (1) we don't feel the Earth's motion, (2) unattached objects don't fly off, and (3) no annual stellar parallax. [http://physics.gmu.edu/~jevans/astr103/CourseNotes/history_greekGeocentricHeliocentric.html] Stellar parallax was not measured until 1838, while (1) and (2) were resolved by the work of [[Isaac Newton]].</ref>

In fact the Copernican theory was no more accurate than the Ptolemaic model. It had no compelling physical arguments for its superiority, and it proposed no experiments for testing its novel features. In some respects, it was actually less accurate, as more epicycles had to be added (in place of Ptolemy's [[equant]]).  Copernicus' main argument in favor of his theory was that it was aesthetically more pleasing as it allowed the planets to move in uniform circular motion, an idea later proven false by Kepler.  Many of the ancient Greek arguments for and against [[heliocentrism]] remained unresolved for some time. <ref>Ancient Greeks objected to Aristarchus's heliocentrim because (1) we don't feel the Earth's motion, (2) unattached objects don't fly off, and (3) no annual stellar parallax. [http://physics.gmu.edu/~jevans/astr103/CourseNotes/history_greekGeocentricHeliocentric.html] Stellar parallax was not measured until 1838, while (1) and (2) were resolved by the work of [[Isaac Newton]].</ref>