The Universe Explained

9 Pages 2353 Words

“Our picture of the universe.” This introductory section shows the desire for Man to find a complete description of the universe we live in. From the Greek philosopher Aristotle’s theory of a spherical earth, to Edwin Hubble’s observations of distant galactic movement, Hawking describes the scientific theories and studies of early philosophers and scientists. These partial theories and observations lay the groundwork for the search of a complete and unified “ultimate theory” of the universe.
With this stated, Hawking continues into the description of space and time. In his explanation, he shows how space and time are relative by involving Newtonian physics and the science of Galileo and Aristotle. The difference between the ideas of Aristotle and those of Newton and Galileo is that Aristotle believed there was a referred. In particular, he believed that the Earth was at rest. Whereas, Newton using Galileo’s experiments founded three laws of physics that showed there was no fixed state of rest. Taking this into account, experiments involving the speed of light led to Albert Einstein developing general the theory of relativity. From Einstein we learned space and time are dynamic quantities and the notion of time and length became relative. Energy and mass are equivalent, related through the famous equation E=mc2. Space and time not only affect but are affected by everything that occurs in the universe.
A remarkable result of Einstein’s general theory of relativity is the expansion of the universe. Although this expansion is not noticeable by us humans, the universe is in fact stretching causing its contents to drift apart. For example, when you view a plane in the sky it appears as if it is moving relatively slowly, when in fact it is flying at speeds usually near 300 mph. Similarly, when scientists view far galaxies, they see them moving away from earth and away from each other. This leads Hawking to the explai...