Through centuries science and its theories have defined and analysed numerousoccurrences right from the formation of an atom to the latest artificial intelligence. We bring to yousome of the theories that revolutionized the world of science….
In astronomy, heliocentrism is the theory that the Sun is at the center of the Universe or the Solar System.The word is derived from the Greek word Helios meaning Sun; and kentron meaning “Center;. This theorywas a sharp contrast to the earlier understanding which placed the Earth at the center, called geocentrism.
The theory that the Earth revolves around the Sun and rotates on its axis had been proposed as early asthe 3rd century BC by Greek astronomer, Aristarchus of Samos. This was a dangerous assertion at thetime and being denounced as against religion, could not win over supporters of the geocentric model. Sowhile the sphericity of the Earth was widely recognized in Greco-Roman astronomy from at least the 4thcentury BC, the issue did not assume any importance, however, for nearly 2,000 years. In fact, the Earthsdaily rotation and yearly orbit around the Sun was never universally debated until the CopernicanRevolution.
The Copernican Revolution
Nicolaus Copernicus explained that the sun is at the centre of the universe and we move around it alongwith all the other planets. This is called the Heliocentric Model which was published in his manuscript, “Onthe Revolutions of the Celestial Spheres”. His observations, confirmed the heliocentric theory byAristarchus, who attributed the annual reappearance of the constellations in the same celestial position tothe Earth orbiting the Sun. This, and periodic reappearances of Mercury, Venus, Mars, Jupiter and Saturn,in the same respective celestial places, persuaded him to proclaim that all planets orbit the Sun. However,due to fears that the publication of his theories would lead to condemnation from the church he withheld hisresearch until a year before he died. It was only in 1542, when he was near death, that he sent hismanuscript to be published. The Copernican model makes the claim of describing the physical reality of thecosmos, with the heavenly bodies in rotation around the Sun, and introduced Earths daily rotation on itsaxis.
Like Copernicus, German scientist Johannes Kepler asserted the physical reality of a heliocentric model asopposed to a geocentric one. Kepler concluded that certain mathematical laws govern planetary motion.One of those laws discarded the assumption that planets moved in uniform circular motion, replacing it withelliptical motion. This showed that Copernicus’s basic ideas were true.
Galileo’s Telescopic View
Ultimately it was Italian scientist, Galileo who used his telescope to affirm the heliocentric theory. In 1610,he discovered moons orbiting Jupiter. Galileo also used his telescope to observe mountains and volcanoeson the Moon, sunspots, individual stars within the arm of the Milky Way and moon-like phases for Venus.
This observation of Venus is what gave proof to the theory of heliocentrics. If one imagines a universe inwhich Venus is always between the sun and the Earth, it could never appear fully illuminated thanks tobasic geometry. It would always appear like a crescent moon of some sort; its fully lit side would always befacing away from Earth and toward the more distant sun. Galileo demonstrated clearly that this was not thecase. However, he was put under house arrest by the church and it was only 350 years after his death thatthe theory of heliocentrics was completely established.
Do you know?
In 5th century AD, the Indian astronomer Aryabhata also proposed a heliocentric Universe. However, as hiswork was not translated into Latin until after Copernicus had written De revolutionibusorbiumcoelestium,his theories were apparently unknown in the West.
–Manoj Mahanta
Team, ScienceNow Digital
