The sun, the moon, the stars all rotated around the earth.  The earth was the center of the universe.  That was the thinking back in the middle ages and had been since ancient times.  But along came a Polish astronomer – Nicolaus Copernicus.  At the time his theories among philosophers and theologians were an outrage. 

Copernicus wrote in a 6 volume thesis that the earth actually revolves around the sun.  He also pointed out other planets in the solar system, estimated their distances from the sun and that the earth rotated on its axis, making a complete rotation each day.  He theorized that gradual shifts of the earth’s spinning on its axis was the reason for the change of seasons.  He didn’t quite get that one right – but he was on the right track.

Actually most of his theories were accurate but he never lived long enough to find out he was right.  He died the year his thesis was published and it wasn’t until a couple hundred years later that even his estimates on the distances from the sun to the other planets were pretty close. 

Nicolaus Copernicus died on this date in 1543.