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Running head : PHYSICS RESEARCH ASSESSMENT                                          1

Physics assessment task Tiittle : cosmic engine research task Sandy Kawashima Carlingford High School

Author Note This paper was prepared for taught by Mr

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Question 1	(a) Outline the major features of Aristotle’s model of the universe including a diagram                                             2

Plato's student Aristotle was born in 383 and he proposed the model around 340 BEC and the model being the Geocentric model in this mod also known as "geocentrism"and  in this model  the earth at the center of the universe also the earth stationary, Aristotle accepted the 55 transparent concentric  spheres it used to explain the earth at the center of the universe and the other planets ,moon and the sun rotating around the earth. In an attempt to explain the retrograde motion of the planets, the other Greek philosopher Eudoxus had proposed that earlier ,the planets were attached to sphere that were attached to other spheres he himself added more spheres to the model bringing the total up to 55 transparent concentric spheres to improve accuracy. Aristotle also taught that the Earth was unique in the Universe, with its own set of physical laws that were different from how things worked up in the Heavens. but the model not perfect it could not explain the change in the brightness of the planets or the size of the moon in the sky

[Diagram]

(b)    Identify the limitations of Aristotle’s geocentric model of the universe. Describe how one future model tried to modify Aristotle’s model to remove shortcomings? Aristotle’s model is not perfect it couldn’t explain the change In the brightness, of the planets or the size of the moon in the sky, then Claudius ptolemeaus is an ancient Greek philosophers, he modify the Aristotle’s model to remove shortcomings. More accurate observation of planetary motion directed this refinement. He developed a complex model based on concentric which had the planets orbiting the earth in not quite circular orbits with not quite constant speeds; he also used Hipparchus’ idea of epicycles to explain the retrograde motion of the planets

©	Describe the limitations placed on the development of various models of the universe by the technology available at the time.

Question 2     Discuss the contributions of A. Einstein, A. Friedman, and E. Hubble to our current understanding about the origin of the universe.

E Theory has the universe beginning as pure energy, which as it expanded and cooled ,was able to ‘transform’ into matter according to Einstein’s famous equation E=mc^2

F Predicted by Friedman in 1948, the suggestion was that the universe started  with a highly energetic explosion, then the remnants of the energy associated with that explosion should be able to be detected as a ‘ background radiation ‘ of wavelength about 1 mm thoughout all of space .He estimated that the expansion of the universe would have resulted in its cooling down to about 3 degrees kelvin. this was detected in the late 1980s and studied extensively in the early 1990s, following the launch of the cosmic background explorer (COBE) satellite .the radiation had the properties Friedman had predicted and permeated the universe with very little variation.

H Hubble established the relationship between the distance of a galaxy from us and its velocity as measured by its red shift .He discovered that the further the galaxy away, the faster it is moving. in the late 1920s and early 1930s, Edwin Hubble showed that the wavelengths of the spectral lines from other galaxies in the universe are red shifted. this phenomenon is called the cosmological red shift and means that as time goes by ,cluster of galaxies are getting further apart-the universe is expanding .Hubble &Humason showed further that the greater the distance to a galaxy the greater the red shift, so the further away the galaxy is from us , the faster it is receding. Hubble’s law suggestests that the universe is expanding uniformly. it is important to realize that each galaxy, or cluster of galaxies , does not expand as it is held together by its own gravitational forces. It is the intergalactic space between widely separated galaxies, or cluster of galaxies , which expands with time.

Question 3 Explain how you have assessed the reliability and validity of the information you have gathered