Sun has always held a special place in every mythology and civilization of the world. One will be surprised to know that while Sun was one of the highest gods as per their beliefs, still ancient humans considered Earth as the center of the Universe and not the Sun.
Geocentrism Vs Heliocentrism
Ancient humans visualized the pattern of hunters and animals in the constellations of stars, and built stories around them; these patterns became their gods, and helped them in hunting and surviving tough conditions. The first civilizations throughout the world and the belief of Earth being at the center of the Universe, shaped one of the first views of the cosmos known as Geocentrism.
So, how did we finally realize that it was the Sun at the center, not the Earth? In ancient days it was Nicolaus Copernicus who started the Copernican revolution that made us realize that it was indeed the Sun at the center around which all planets revolve. But he was not the first one to think about it.
In the 4th century BC, there was a Greek philosopher named Philolaus who thought something completely opposite to the beliefs of the Hellenists. He proposed that there was a big ball of fire at the center of the Universe and every other planet and our Sun was revolving around this “Central Fire”.
Although we are certain that this is untrue, this theory inspired a different Greek to posit the first Heliocentric model of the universe. He was Aristarchus of Samos during the 3rd century BC. He calculated the size of the Earth, Moon, and the distances between them and the Sun.
According to his calculations, the Sun was around 6 times wider than Earth. He was the one who observed the eclipses formed on the surface of the Moon and declared that it was caused by the motion of the Earth and Moon around the Sun. But his theory was largely discarded and later during the 2nd century BC, Ptolemy again reverted back to the geocentric model of the Solar System.
Aristarchus of Samos is considered one of the greatest astronomers of antiquity along with Hipparchus, and one of the greatest thinkers in human history. In the western world, the next phase of discussing heliocentrism came back again at the beginning of the 16th century.
Europe while reading through the old texts and discovering its old heritage of Hellenic and Platonic philosophy, left the Dark Age and entered the age of the Renaissance. During this period in the year 1514, Copernicus showed his work about the Sun being the center of the Universe.
On the other side in India, great mathematician Aryabhata was recording the rotatory motion of the Earth and the period of motion of planets with respect to the Sun. This theory is open to debate whether Aryabatta truly discovered the heliocentric model or not but certainly, his findings have put the Sun more on the central pedestal than Earth.
In the 15th century, another Indian mathematician Nilkantha Somayaji, of the Kerala School of Astronomy and Mathematics proposed that all planets move around the Sun but the Sun instead moves around the Earth. This theory is known as geo-heliocentrism and was later used in Europe too, as per the model of Danish astronomer Tycho Brahe.
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In the Middle-East Arabic world, different planetary models were studied and those studies were later used by the great Copernicus in his seminal work. Now here religion and science were running parallel and Copernicus was not so courageous to declare his work that goes directly against the church’s beliefs.
Thus the theory was presented as a complete mathematical model and a hypothesis that may be corrected further. Even the book was dedicated to the Pope and the church finally accepted it, as it was useful for the computation of the position of planets.
Later came Galileo and the situation completely changed. He developed telescopes and began to observe the night sky. While looking through the lens, he found out that there are lots of stars that don’t seem visible to the naked eyes. He observed the phases of the Moon and found that its surface must have been disoriented with an imperfect outer layer.
This challenged the popular belief that everything in heaven is made by god and cannot be imperfect. He also studied the phases of interior planets such as Venus. All through his analysis, he was the first one to propose that Copernicus’ theory was not a hypothesis but a fact, and it is the Sun that is at the center and all planets including the Earth are revolving around it.
Galileo’s support of Copernican heliocentrism was met with opposition from within the Catholic Church and some astronomers of that time. The matter was investigated in 1615, which concluded that heliocentrism was foolish, absurd, and sinful since it contradicted the “Holy Scriptures”.
Galileo later defended his views in his book “Dialogue Concerning the Two Chief World Systems”, which appeared to attack Pope Urban VIII and thus distanced both the Pope and the Society of Jesus also known as the Jesuits, who had supported Galileo up until this point.
The Pope banned all books and letters advocating the Copernican system. Galileo was home arrested for the rest of his life and there he died due to a long illness. Yet another example of the sheer ignorance of people towards science. It was Sir Isaac Newton who made the theory of heliocentrism acceptable to the medieval world.
He was studying the works of Johannes Kepler. Kepler, on the basis of the Galilean mechanism, proposed that planets revolve around the Sun in an elliptical orbit with the Sun present at one of the two foci.
Newton made this analysis of Kepler compatible in the terms of the theory of gravitation that keeps the Earth in orbit around the Sun. Also, the Sun was not the center of the Universe but a point of the common center of gravity for the Earth and other planets. This common center is now known as Barycenter.
The center of gravity is not always in the center of the object. Some parts of an object may have more mass than other parts. A sledgehammer, for example, has most of its mass on one end, so its center of mass also known as the center of gravity is much closer to its heavy end.
The barycenter is usually closest to the object with the most mass. So, technically all planets revolve around the barycenter of the solar system, not the Sun. But since the Sun contributes almost 99% of weight to the solar system, this barycenter lies near the center of the Sun.
Finally, in the first half of the 18th century, the ban on books related to heliocentric theory was lifted. The evolution of heliocentrism is a beautiful example to show how religion and science run parallel to each other, all we need is a bit of acceptance to hear new ideas and proposals, and always keep asking questions to unravel the very mysteries of the cosmos.
As Galileo said that neither scripture is chained to explain the law of physics; nor God is any less revealed in nature. Do you think we would have known much more about our Universe if people in religion and science worked together?
Let us know in the comments what are your thoughts about Geocentrism and Heliocentrism (geocentrism Vs heliocentrism). If you found this post interesting, please share with your friends. Thanks for reading.