For hundreds of years people had believed that the earth was in the center of the universe. This theory was born of Ptolemy’s geocentric theory. This theory, in brief, stated that the sun revolved around the earth, and so did all the stars. It also stated that the earth was stationary.
Not all ancient astronomers and mathematicians came up with incorrect theories, however. The ancient Greeks knew that the earth was round and they measure the circumference of our earthly sphere using a system of shadows.
Until the time of a very important scientist, people blindly believed this theory. That is, they believed it until the time of the man who would change their beliefs forever.
Nicolaus Copernicus was born in 1473 in Royal Prussia near Poland. His father was a wool merchant, but Nicolaus decided to follow a different trade.
Nicolaus, after making observations, wrote a book called The Revolutions of the Heavenly Spheres, in which he explained his new theory: heliocentricity. Heliocentricity is a Latin word and it means the sun (helio) in the center (centric). His book was published on the day he died in 1533. His theory was not perfect, but it was a major step up the ladder of improvement.
Johannes Kepler (German) and Tycho Brahe (Danish) were both renowned sixteenth century scientists. They developed and improved the theory of heliocentricity. Brahe even invented his own idea: the Tychonic theory, by combining the works of Ptolemy and Copernicus. Kepler wrote books about the laws of planetary motion.
The main argument against heliocentricity was that there was no stellar parallax. Stellar parallax is the different views you have of the stars from different angles. So, if the earth was halfway around the orbit, the view of the constellations would thus be different that if it was in the beginning of its orbit. This was not so, and this argument was used by the people who opposed of heliocentricity until very sensitive telescopes discovered that the stars do move, but in tiny amounts because the’re so far away.
All of these scientists contributed to the study of the universe and helped us gain the knowledge we know today.
This is a brief overview of the improvement of the view of the universe through the Scientific Revolution.