# Preliminary Physics Assessment Task 1 Christos Toras   MODELS OF THE UNIVERSE -

1200 WordsApr 23, 20195 Pages
Preliminary Physics Assessment Task 1 Christos Toras MODELS OF THE UNIVERSE - TIMELINE From the time of Aristotle up until the time of Newton there were five models of what humans thought of the universe. The astronomers who developed these models were Aristotle, Ptolemy, Copernicus, Tycho Brahe, Kepler, Galileo and Newton. Aristotle’s model of the universe was a geocentric universe. This meant that the Earth was at the centre of the universe and that all stars were on a celestial sphere. A celestial sphere is an imaginary sphere which acts as a dome around the Earth from which you can see the stars and the universe. Although Aristotle’s model was good for its time it could not explain retrograde motion of the planets.…show more content…
His model said that the planets moved not in circles around the sun, but in ellipses and the mathematics was proved using three laws: 1. The Law of ellipses, which means that each planet travels around the sun in an ellipses. 2. The Law of areas, which means that all planets sweep out equal areas in equal time. 3. The Law of Periods, which means the time it takes to complete an orbit. These three laws allowed Kepler to work out the relative distances between planets. During the time of Galileo, the church was very strict with physicists who believed in the Copernican model. This is exactly the position that Galileo found himself in. In 1600 Galileo began making his own telescope. He became the first person to point one at the night sky. What staggered him the most by doing this was the sheer volume of stars that were not visible with the naked eye. Galileo used his telescope to make many discoveries; one of these is the discovery of Jupiter’s four moons. He even plotted and tracked there rotations around Jupiter. The main thing however, was that Jupiter even had moons, this was proof that the geocentric model was incorrect and that this discovery was in favour of the Copernican model. Newton’s most important work, titled Philosophiae Naturalis Principia Mathematica contained his famous laws of motion, as well as new types of maths. Newton