Welcome to Marine Science 100 mid term review. We are going to review one through twelve as outlined in your introduction to Marine Science 100 Student Telecourse Handbook. All right. Getting started, we look at the world around us and we find that the reality is that we live on a water planet. Over 70 percent of the earth’s surface is covered with water. That leaves a very small chunk of the area that is land. It hopes if we go back to the beginning. The beginning for us is when the universe began and what we think was a big bang. We believe that for whatever reason all the matter in the universe was compressed in a single deminsionalist dot that for whatever reason exploded about thirteen to fourteen billion years ago. The cataclismic event is termed the Big Bang. About a million years after the big bang the universe cooled enough for atoms of hydrogen the most abundant type of atom in the universe to form. About one billion years after that collapsing masses hydrogen started forming the first stars. Our own star, which we call the sun, formed about 5.5 billion years as clouds of hydrogen condensed upon each other pulled together by gravitational attraction. As the hydrogen shrunk it heated to enormous temperatures triggering nuclear fission. During this thermal nuclear reaction the sun’s hydrogen atoms combined forming the larger helium atoms and releasing a steady stream of energy.
The formation of the planets themselves began about five billion years ago. The heavier elements that make up the planets, moons and comets are produced in the nuclear fusion and explosive gas of other stars. The earth and the oceans upon it are the direct result of a super nova explosion.
About five billion years ago the solar nebula was rotating in about 75 percent hydrogen and 23 percent helium and about two percent other materials. Solar nebula spun faster and faster, material concentrated near the center became the proto sun and much of the outer material...