The great Polish astronomer Niklas Koppernigk, or Nicholas Copernicus the name
by which he became famous, published only little parts of his studies during
his active live, still he was very well known in his days as astronomer
and mathematician. He developed various fundamental and important theories.
The best known
is his theory of the rotation of the Earth.
In his days the rising, crossing through the
skies and sinking of the Sun, Moon, planets and stars was dued to the movement
of the celestial bodies itself, while the Earth was fixed at its place.
Copernicus understood however that this had to be explained by the rotation
of the Earth around its axes. He suggested this, because he could not
imagine that much larger Universe was turning around the Earth.
Planetary system
of Copernicus.
Besides this Copernicus placed as first astronomer
the Earth in an orbit, just like the other planets. He sticked,
however, to the old theory of the uniform circulair movement, so
he had to suggest that there were various centres of planetairy orbits,
to explain the variations in the orbits of the Moon and other planets.
The center of the Earth's orbit was placed
by him in the center of the Universe, the motions of all planets
were related to this point. According to him the Sun was positioned near
the center of the solar system, but seemed to have no relation at all with
the planets.
Copernicus knew that his explanation was not
completely correct, amongst other things he realised that the rotation
of the Earth in its orbit should cause a continuous repositioning of the
stars in the sky (the outer orbit). He assumed however that the distance
between the stars the Earth was so large, that it would not be possible
to observe these very small variations in position.
The planetary system of Copernicus was not accepted
by the scientists of his time, in the cause of the history however astronomers
realised that his theories were the turning point in the ideas of the place
of the Earth in the universe.