The Sun: Man's Friend & Foe

Throughout history there have been 4 main theories about the Sun and its relationship to the Earth. The following table briefly outlines these theories.

The Dimension	Pre-Scientific Conception	Geocentric Conception	Heliocentric Conception	Sidereal Conception
Space	Infinitely flat	Earth surrounded by sky.	The Sun at the center of a small universe	Our solar system is one of many in a universe.
Celestial objects	Sun, moon, and stars	Sun, moon, planets, stars	Sun, moons, planets, stars	Includes multitudes of objects.
Equipment available	Eye, feeling	Eye, brain	Eye, brain, optical telescope	Eye, brain, telescope, photometer, spectrometer, and others.
Source of order and motion	Will of the gods	Natural motion	Gravitational forces, electricity	Gravitational forces, electricity, and nuclear force

"The Universe is populated by innumerable Suns, innumerable earths, and perhaps, innumerable forms of life. That thought expresses the essence of the Copernican revolution. No revelation more striking has ever come from the scientific mind."

- Robert Jastrow, 1989