Sun-centred vs. earth-centred universe

The paper ” Sun-Centred vs. Earth-Centred Universe” is an excellent example of an assignment on history. Ancient people believed that Earth is the center of the universe. The reason for this belief is the fact that every morning sun rises in the East and throughout the day it travels towards the west and finally sets in the west. People believed that Earth is a stationary object and other stars revolve around it since they never felt any sensation of movement on Earth. This is called the geocentric theory nowadays. During the 4th centuries, y, Greeks proposed that stars are fixed in a celestial sphere and other planets, sun, and moon are revolving underneath this celestial sphere. Many such models and concepts were proposed to prove this theory but finally, the Greek astronomers realized that there are some weaknesses related to this concept. The concept of Earth Centered Universe was widely accepted until the theories proposed by Nicolaus Copernicus, Galileo Galilei, and Johannes Kepler. The heliocentric model was proposed by Copernicus which was based on the notion that Earth and other planets revolve around the sun. The retrograde motion was described clearly in this model and illuminated some more facts in favor of the notion that Earth is NOT the center of the universe. This model also illuminated the orbits and movements of Mercury and Venus making the model more credible than all the previously proposed theories and models. This model started the search of the truth behind the sun-centered universe and finally, during the 19th century, Bessel’s work proved that Earth has a yearly rotation around the sun.