# The Sun Revolves Around the Earth

At least since the time of Ptolemy, a Greek astronomer who lived in the first half of the Second Century A.D. until 1543 when Nicholaus Copernicus published De Revolutionibus Orbitum Coelestium man believed the Earth was the center of the universe, which at that time consisted of the sun and a few planets and stars that could be seen with the naked eye.  This was understandable because the sun appeared to rise every morning in the east, cross the sky and set in the west.  Copernicus challenged the earth-centric notion of things by postulating that the sun was the center of the solar system and that Earth and the other planets revolved around it.  So as not to offend the Church (that is, to avoid banishment), his book contained a disclaimer to the effect that his theory was more of a mathematical exercise than a statement of the way things are.

Copernicus believed that the planetary motions were circular, a throwback to the old Greek view that the circle is the most perfect geometric shape.  Another astronomer of the same time, Johannes Kepler, found that this view didn’t match the observations of a third astronomer, Tycho Brahe.  Kepler worked out the laws of planetary motion which predict that planets orbit the sun in elliptical shape, moving between two points of proximity to the sun, aphelion, when they are nearest to the sun and moving fastest, and perihelion, when they are farthest and moving slowest.

Approximately the same time, Galileo Galilei dropped out of medical school and began studying dynamics, the laws of moving bodies, which is now called mechanics.  He developed an early theory of relativity by questioning whether a stone dropped from the top of a mast of a moving ship would hit the base of the mast or would have the ship move under it and strike nearer the stern of the ship.  The latter result was predicted by Aristotlean theory, which said that the stone would stop moving as soon as it was released.  This was debated for years without anyone bothering to actually drop a stone from the mast of a ship.  Three centuries later Einstein extended this theory of relativity to electromagnetic waves.

By the age of 40 Galileo was engaged in astronomy, looking at stars through the newly-invented telescope.  He predicted that a bright light in the sky, something we now call a nova, would eventually fade and disappear.  This brought him under scrutiny by the Church, which viewed any change in the heavens as contrary to God’s work that is unchangeable.  Galileo went blithely on without regard to growing animosity and eventually confirmed Copernicus’ theories of planetary motion around the sun.  For his effort, in 1633 at age 69, he was brought before the judges of the Holy Office of the Church and “confessed” to heresy.  He was confined to his villa, essentially under house arrest, until his death in 1642.

Galileo’s experience with religion, and that of others over the centuries, undoubtedly spawned the tension between science and religion that continues even to today.  Stephen Hawking wrote in his book A Brief History of Time, that he and other physicists once had an audience with the Pope in which the Pope, apparently wanting to avoid another incident like Galileo, told the group that there was nothing wrong with trying to figure out how the universe began, but to leave alone anything that occurred before the Big Bang, as that was the work of God.  It is no wonder, then, that scientists cannot bring themselves to offer any hypothesis that includes any kind of Creator.