Earth Formation
Kevin Navarrete Benham, Timothy ENC1101 Mon-Wed 9:30-10:45am 4-1-13 Formation of Earth and life on earth. About 4. 57 Billion years ago our planet earth was formed. Earth contains many things that allows us to live. How was the Earth formed and why do we live in it is a question many of us would like to find out, but there are many answers to these questions and we cannot come up with a conclusion. The theory that is said to explain the formation of our earth is called the Big Bang Theory.
This theory explains that all matter in the Universe was, at one time, concentrated in a giant mass (a black hole) that blew apart about 10 to 20 billion years ago and is still expanding. Now a days, it is thought that our solar system had its first steps when, about 5 billion years ago, by some unknown process, a cloud of dust and gases collapsed and condensed. Some of the matter in the central mass compressed under its own gravity, condensed, and heated until forces were so strong that thermonuclear reactions began. These reactions were the origin of our star, the Sun.
The size of a star is related to the amount of fuel it has available to burn for energy and how fast it burns up that fuel. A star smaller than our sun would not contain enough fuel to last long enough for evolution to have occurred here on earth. A larger star would have burned its fuel too fast, and would have burned itself out long ago. It would also not last long enough for life to evolve on Earth. The center of the disk became the sun, and the particles in the outer rings turned into large burning balls of gas and molten-liquid that cooled and condensed to take on solid form.
Four or five billion years ago, they turned into the planets that we know today as Earth, Mars, Venus, and the outer planets. A cloud with dust gases and many more particles grew together and condensed to form the planets, comets, asteroids, and many other things about 4. 6 billion years ago. It is thought that Earth began as a very cold world. It is also thought that the very first atmosphere could have been of hydrogen gas. Since this gas is so light weight and very chemically reactive, most of it would have floated off into space or reacted with other substances.
The first atmosphere is thought to be due to volcanic eruption and other chemical reactions taking place. It is thought that the inner four solid planets may have began with similar atmospheres of H2O, CO2, CO, and N2. It is thought that these chemicals made up the atmosphere of our planet for the first 1 billion years. It then provided similar atmospheres for the other planets Over the past few centuries scientists have been trying to answer the question: what was the origin of life? There have been a number of scientists who have produces a number of plausible theories.
The currently most excepted theory is Oparin’s theory, which states that the “origin of life on Earth was in nonliving chemical substances which spontaneously formed in Earth’s early atmosphere and combined to make more complex chemicals until living cells were formed. ” This maybe a possibility because Stanley Miller a student at University of Chicago, began experimenting to prove Oparin’s theory. He created a device that dispersed gas’s that were likely to be present in the early atmosphere, and then he pased an electrical discharge, stimulating the UV rays present in the early atmosphere.
After allowing the experiment to continue for a week, the results were amazing. However, there have been other theories that do not support this experiment. The Cosmozoa theory which states that life was brought to earth from somewhere else, and the theory states that life can suddenly and spontaneously appear. All in all there are many perspectives and theories of the origin of life and the formation of the Earth. Each of these theories sound very good, but there is no proof that it really happened this way. Word Count 1207
