Achievements in Ancient to Modern Astronomy - Essay Example

Name) (Instructor) (Institution) (Course code) (Date) Abstract This research paper explores the various achievements in the ancient astronomy. It also compares both the ancient and modern achievements in astronomy. It further explores the changes and advancement in astronomy, from the ancient to the modern changes. It looks at various discoveries and inventions by both ancient and modern astronomers. This paper explores the following areas in its quest to explaining and comparing astronomical changes in the ancient and modern astronomy: heliocentric system; hybrid model describing the movement of the moon and earth; laws of planetary motion; changes in astronomy towards the end of the 19th century; and opinion regarding the shape of the earth. Heliocentric system explores the position of the sun as being the centre of the universe. Hybrid model explains the movement of the moon and sun orbiting the earth and how other planets revolve the sun. The laws of planetary motion show the three laws which guide the movement of planets around the sun. It also outlines changes and advancement in astronomy and explains the actual shape of the earth. An Assessment and Comparison of the Ancient and Modern Astronomy Astronomy is the scientific study of the universe, especially of the sizes, positions, motions, compositions and behavior of astronomical objects. This study is based on ancient and modern astronomical objects such as planets, stars, moon, earth and sun. It helps us understand our universe and its constituents and how they relate to one another. In this paper, both ancient and modern achievements have been considered, and a comparison of the same has also been discussed. Also, a discourse of discoveries, inventions, changes and advancement in astronomy since the ancient times to the modern days, has been explored. The discovery of the heliocentric system is one of the ancient astronomy achievements. This discovery established that the sun is at the centre of the universe. Initially, the earth was considered to be at the centre of planetary motions. The sun was perceived to be in constant motion, which was not the case. The daily rotation of the stellar sky is as a result of the rotation of the earth on its own axis (Evans, 1998). It was discovered that all other planets revolve around the sun. This motion can be viewed from the rotating earth. The earth takes 365days to make one complete revolution. Evans (1998) noted that planets orbits in oval shaped paths with the sun remaining constant. Circular orbits are the paths that planets use to go round the sun, which is at the centre of the universe. Hybrid model describes the movement of the moon and sun orbiting the Earth and how other planets revolve around the sun. It was believed that the other planets and sky surround the earth which was stationery. This was in conflict with other astronomer’s ideas that discovered the rotation and revolution of the sun. “Early astronomers also established the nature of comets as objects of translunar space and not atmospheric phenomena, as had been postulated by Aristotle” (Bunson, 2009). The elliptical orbits through which the planets move around the sun were discovered by a German astronomer, Johannes Kepler who studied their movements and derived three laws of planetary motion. He noted that “The orbit of each planet is an ellipse with the Sun in one focus”. This first law showed that other planets orbits around the stationary sun which is rotating on its own axis. Secondly, he established that (Karam & Stein, 2011) “The radius vector from Sun to planet sweeps equal areas at each time, meaning that the planet moves faster when closer to the Sun” (Karam & Stein, 2011) This implicated those planets closest to the sun moved faster than those far away from the sun. Therefore, mercury’s speed around the sun is faster than Pluto’s speed orbiting around the sun. Finally, in the third law, he concluded that “the squares of the revolution periods are proportional to the cubes of the mean distances from the Sun for all planets” (Karam & Stein, 2011). This further showed that the sun was at the centre of all planetary motions. The discovery and introduction of laws of planetary motions marked major achievements in ancient astronomy. Galileo further studied the heliocentric system and came up with evidence with his telescopic inventions of the moons and phases of other planets. In 1729, the Earth’s movement around the sun was finally proved. This was as a result of a discovery of the aberration of light from the stars, caused by the combination of the Earth’s motion with the limited velocity of the light. The invention of the modern telescopes has greatly enhanced the study and further discoveries and proofs concerning the planetary motions” (Karam & Stein, 2011). Towards the end of the 19th century, a number of developments marked numerous changes in astronomy. Until mid-19th century, stellar magnitudes were estimated by visual observation thus limiting the accuracy of the actual magnitude (Neugebauer, 2012). A visual photometer was discovered in 1861 which greatly improved the accuracy of the measurement of the stellar magnitude. Photometry was further advanced by the introduction of the photoelectric cells, which accurately determined stellar magnitudes by measuring photographic plates. In 1666, advancement in astronomy was made following Isaac Newton’s discovery of spectrum. He showed the decomposition of sunlight into a spectrum when passed through a prism. Later on, another astronomer found dark lines in the “solar spectrum”. Another achievement was made when hot solids were found to discharge light in unremitting spectra while hot gases produce line spectra. Astronomical photography was enhanced with the discovery of dry photographic plates in 1871, which made long lasting photos of the moon, sun and other stars obtained (Neugebauer, 2012). Better large telescopes were discovered to replace the 18th and early 19th century, small refractors and larger metal mirror reflectors (Evans, 1998), which were the telescopes available for ancient astronomers. Telescope optics was improved when an achromatic objective was discovered and later used to construct larger refractors. The reflector techniques were advanced by the invention of glass mirrors which was later used to come up with the modern 6.1-meter telescope. The ancient and modern astronomers held different opinions regarding the shape of the earth. Ancient astronomers asserted that the earth was flat and was resting on the water. Ancient astronomy also held that the earth was cylindrical such that its bottom rest on the water while the top supports life (Poynting, 2012). Others were of the opinion that the earth is suspended in the air and that was supported by nothing. Anaximenes of Miletus was of the opinion that the earth was disc shaped and that was being supported by the air beneath it. Therefore, it is clear that the ancient astronomy, with regards to the shape of the earth, does not correspond to the modern astronomy which has proved the shape of the earth to be spherical (Poynting, 2012). Poyiting (2012) wrote that modern astronomy holds that the earth is spherical. The earth lies at the centre of the universe. Its spherical shape is as a result of the natural tendency of the heavy elements to be pulled towards the centre of the universe. Circumnavigation as a proof has shown that the earth is spherical. This involves travelling or sailing around the globe in a constant direction from one place. Eventually, you will come back to the same starting position provided you maintained a particular direction. If the earth was not spherical, this would not be possible, as it can only happen in movement along the sphere (Poynting, 2012). The argument on the sailing ships also confirms that the earth is spherical (Neugebauer, 2012). Ptolemy writes, “if we sail towards mountains or elevated places, they are observed to increase gradually in size as if rising from the sea itself in which they had previously submerged”. This is attributed to the curvature of the water surface. Also, as the ship sails away from the port, their hulls are seen to disappear first as the mast and rigging can clearly be seen. The same happens when the ship is approaching the port, such that their hulls are seen first then some parts and finally the whole ship. This shows that the earth is spherical (Poynting, 2012) This research paper has clearly explored some of the various achievements from the ancient to the modern astronomy. The achievements in the ancient times cannot be underestimated as it formed the basis of modern astronomy. Advancements were made to improve, prove and discover better and easier ways of studying astronomy. Modern astronomy has greatly contributed to today’s civilization and developments in the world. References Bunson, M. (2009). The encyclopedia of ancient Egypt. New York: InfoBase Publishing. Evans, J. (1998). The history & practice of ancient astronomy. New York: Oxford University Press. Karam, P., & Stein, B. (2011). Planetary motion. New York: InfoBase Publishing. Neugebauer, O. (2012). A history of ancient mathematical astronomy. Berlin: Springer Science & Business Media Poynting, J. (2012). The earth; its shape, size, weight and spin. Cambridge, England: Cambridge University Press. Read More