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Union University Department of Physics

The Science Guys



Science Guys > January 2004

January 2004

Is it true that Copernicus’ heliocentric theory delivered a severe blow to man’s pride and religious dogma?

Historically, there were two fundamental views of our Earth and the universe: (1) The Earth is the center of the universe, with the sun, planets, and stars moving around it in circles (geocentric) (2) The Sun is at the center of the solar system with the Earth and planets revolving about it (heliocentric).

The Greek philosopher Aristotle (~325 B.C.) was the most famous proponent of the geocentric theory, which seems reasonable because objects in the sky appear to move around the Earth. However, Aristotle placed the Earth at the center because of additional beliefs. In his view, there were only 4 elements: Earth (heaviest), Water, Air, and Fire (lightest). He believed that heavier objects were drawn to the center because of the "influence of the center." Therefore, the Earth had to be at the center because it was heavier. This theory was accepted as logical and promoted by the church for centuries.

The Polish astronomer, Nicholas Copernicus (∼1540), proposed the heliocentric theory. (Actually, Aristarchus (∼250 B.C) had promoted the heliocentric theory but it was not popular in his time.) Copernicus adopted a heliocentric view because it better explained the motions of the heavens mathematically. This view had the Earth and other planets moving in circles around the fixed Sun. Copernicus was a devout man, anxious to serve both the world of natural philosophy and the church and hesitated to publish findings that contradicted the church. However, his theories eventually became public and they were accepted by many scientists of the day.

Carl Sagan once confidently declared that the heliocentric theory of Copernicus was one of the "Great Demotions...delivered to human pride." Students are often taught that Copernicus somehow dethroned mankind from a privileged position at the center of the universe. This however is not correct!

During the medieval era (∼450-1450), Aristotle’s geocentrism was taken as evidence for the "grossness" of man and his abode. The Earth was considered a lowly place to which base things of the universe sank. This central or low position was thus indicative of man’s nature and wretchedness!

Then, Copernicus’ magnum opus on astronomy was published. The Earth was promoted from the lowest spot in the universe to the heavens. It was argued by astronomer Kepler (∼1625) that mankind was indeed privileged to be afforded an Earth moving through the heavens from which to better view the cosmos. Science had elevated mankind rather than degraded him.

In actuality, Copernicus’ heliocentric theory has its problems. First, the planets do not move in exact circles around the Sun, they move in oval paths called ellipses. Another important point is this idea of a center. Contemporary cosmology dispels the notion that the universe has a center at all! Science actually makes it possible for each point in space to be regarded as the center!