In modern day astronomy and the study of the universe, individuals usually come up with predictions and then gather information and data in order to prove or disprove their hypothesis. Other astronomers in the history of astronomy did the same and came up with their own conclusions based on the data they collected. Some of their predictions were correct, and some were way off, but for the most part they progressed the study of the universe to the point where society is today. Astronomers such as Ptolemy, Copernicus, Brahe, …Today’s astronomers are making giant steps in the discoveries of new theories and proving or disproving their thoughts all with the help of foundations set by past astronomers.
Ptolemy created the first geocentric model of the solar system that stood in place for over a thousand years. The thought of placing the Earth in the center of the universe made perfect sense for several reasons. The first reason was that the inhabitants of the Earth felt as if they were standing still and not rotating or revolving around any object. Because of the fact that the idea of an atmosphere was not thought of until the future, this was a very good explanation that could not be argued. Another explanation of the Earth being the center of the solar system is that parallaxes involved with the stars showed that the Earth was not moving because technology at the time could not pick up the extremely small increments of movement by the Earth.
Ptolemy also discovered epicycles, which explained retrograde motion. Ptolemy could predict where the planets were going to be even hundreds of years after he died, proving the accurate nature of his maps. There were several problems with Ptolemy’s calculations and maps. His principles were based entirely of mathematics and had nothing to do with physical principles. Math was the only thing that he used to predict and explain his theories, something which caused a tremendous problem with his models. He also had to develop a different type of epicycle for Mercury and Venus, most likely because they are locating inside the Earth as astronomers know today. He also had to offset the Earth on his maps due to an increase in speed by the other planets. His maps of the epicycles of Mercury also became very complex in order to make them work mathematically. Even with all the mistakes that Ptolemy had, he still progressed the field of astronomy for years to come and inspired others to continue research.
Nicholas Copernicus, born in 1473, introduced society into the idea of the sun being the center of the universe and the planets revolving around it. Copernicus’ theory came about because the idea was aesthetically pleasing and satisfied religious beliefs that the sun was the source of life and energy s it should be in the center and have everything revolve around it. Copernicus said that the Earth’s rotation made the sun and stars rotate about. He said that the air above the surface rotated as well so there would be no draft as the Earth spun through space. This was the beginning thought of an atmosphere. He said the Earth orbits around the sun and that the moon orbits the Earth.
Copernicus assumed that the orbits of the planets were circular as Ptolemy had discovered year’s back. He also assumed that planets closer to the sun orbited faster and that was the primary cause of retrograde motion. A planet passing by and forging ahead in orbit would cause for retrograde motion to take place.
There were several flaws in the Copernican system as well due to several reasons. One reason was that he assumed that the planets orbited in a circular fashion, just like Ptolemy. Copernicus really made no significant break through with his theories because he couldn’t predict where the planets were going to be because of the fact that his model was based on the same principles as Ptolemy. The only help that Copernicus provided was that Mercury and Venus were not treated as special cases anymore and fit the mold of the other epicycles.
Then came Tycho Brahe, a Dane who was born in1570. Tycho was a man who took precise measurements to predict future locations of stars in the sky. Brahe also built the “Most accurate naked eye observer ever”(Rieke Aug. 28). Brahe wrote down and collected immense amounts of data on the planet Mars which would, “Prove crucial” (Astrology) to Kepler in his formulation of his laws.
Tycho Brahe hired a man by the name of Johannes Kepler to assist him in deciphering Brahe’s observations. Tycho gave Kepler his observations of Mars, the “Most difficult to interpret” (Rieke Aug.30). After Tycho died, his family wanted to stake the claim of all Tycho’s precise measurements. Kepler also fought for his works and in the end he was given the data to continue research.
Kepler believed that the solar system was heliocentric, such as the Copernican system. With the extreme help of Brahe’s work, Kepler made several advances in science. First he realized that the planets travel in ellipses, instead of the always thought circular motion. Kepler also derived three laws. The first law is “The orbits of planets are ellipses with the sun at one focus of the ellipse” (Rieke Aug. 30). Kepler’s discovery of this law was a great breakthrough because astronomers knew exactly where a planet was going to be and how it was moving. Kepler’s second law says that a planet sweeps out away from the sun in equal areas as it travels along its orbit. It also says that a planet moves faster when it is closer to the sun and slows down as it is leaving the sun. Kepler’s third law has to do with a ratio of the period a planet orbits and the planets semi-major axes. This led Kepler to figure out that a planet further away from the sun has longer years than planets that are closer.
Another astronomer named Galileo Galilee revolutionized astronomy and was essentially the founding father of physics. Galilee’s contributions in the area of objects and their motions, and tried to figure out as much as possible in this area. Galileo developed the concept of inertia and what inertia was. The law of inertia states that and object in motion tends to stay in motion and a moving object tends to keep moving when in travel. Galilee also found the four largest moons surrounding Jupiter. These moons were called the Galilean satellites, in tribute of Galilee.
These astronomers have laid the foundation for astronomers to progress the field and have helped the human race better understand the universe and solar system and how they work. Society can benefit greatly by their accomplishments and astronomy has been progressing because of incredibly intelligent astronomers such as Brahe, Copernicus, Kepler, Ptolemy, and probably the most influential astronomy and mathematician, Galileo Galilee.
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