Biology,_Origin_of_the_Earth

Martim Fortes 11/5/2011 Origin of the earth Ever since the dawn of mankind, people have glanced at the stars looking for answers. Answers about how starts were made, what was out there but most of all, how was our planet created. For many years most thought it was god to create the Earth, but as years went by and science took a bigger part in peoples life, a couple of revolutionary man started looking into this. Searching for answers which had been denied by the church for hundreds of years. They digged into the past where many secrets were hiding. The first theories about our solar system and galaxy started to spread, until finally scientists got an explanation of how the universe was formed. It was the complete opposite of what religion taught and many thought it was a contradiction to religion, meaning that it imposed that god didn't exist. They named the theory Big Bang, because it described what they thought actually happened. It was denied at first but it is now acknowledged as what happened. There is no way to be sure, but this is as good of a guess as scientists can make today. The creation of the Earth is the continuation of what happened during the Big Bang in a way. To understand how Earth was formed, the process of the creation of both the universe and our solar systems must be reviewed. In the case of our universe the Big Bang is the name of the theory. A theory which says the universe came into a state of existence about 13.7 billion years ago. After our universe appeared it inflated which is what the name Big Bang refers to, and expanded from an extremely dense and hot state. According to studies the universe is still expanding. The Big Bang theory is just one of many others about the creation of the universe but it is considered the one with more evidence. The theory states that the universe was at one stage very, very hot. Which is backed up by the discovery of a 2.725 degree of Cosmic Microwave Background radiation. This are some remains of the state in which our universe once was. There are many other discoveries which can back up the Big Bang theory, but none can really almost proove it. All of the theories about Earth's creation are just thoughts based in what we have found. That's why they are called "Theories". The Big Bang theory has been evolving since the first idea of it. It´s an idea that will probably always be changing since people are always discovering new things. The discoveries that geologists are making today will be added to the theory tommorow so it always updated. People do not have a way to exactly know if even the updates are right but there are some doubtfull statements in the Big Bang theory. Billions of years later our solar system started to be created. In the middle of our galaxy (the Milky Way) our protosun (which answers.com defines as-The condensation of material that lay at the center of the solar nebula and accreted material from it to form the sun.) was collapsing due to the force of it's gravity. As it was compressed it started heating and heating. As it's temperature increased at incredible speed it was getting ready for a nuclear fusion reaction to occur. Another way to see it is as an atom bomb waiting to be detonated. When the sun was finally "detonated" it sent great amounts of energy everywhere, alongside with this huge pieces of matter and small particles which were also sent off, some were able to escape the gravitational pull of the sun and drift through space, while others went back. As the matter clouds orbited around the sun some were pulled to the sun... While the few which were able to fail to come back to the sun attracted other pieces of matter to join them. As this clouds got bigger they started getting gravities of their own. So other big matter clouds orbited them. Because these "clouds" were sent at a high speed out of the sun, they were spinning. While spinning they cooled down which allowed solid crusts to form. Eventually they got big enough to be planets. This all happened because of gravity and compression. Gravity in taking part of pulling more mass to the small planets and compression for heating up the sun and sending the matter clouds to outer space. Matter clouds which were pulled together to create what is known as planets and moons. 4.4 billion years matter clouds were all around our galaxy after our suns formation. As the clouds came back to the sun they got stuck to asteroids and other pieces of matter. This cloud had now enough gravitational pull to built a body structure. For years earth was a magma ocean until the earth's fast spin cooled it down and they became solid. . As the "earth" spun, it was cooling of and shrinking at the same time. Eventually the earth cooled enough for other things to start happening and appearing. Earth then was struck by a rock body called the Theia, which was about the size of mars. When this happened a huge chunk of the earth was torn off. The pieces of Earth were now rotating it, until the moment where gravitation brought them together to create what is now called the moon. The years following the creation of the moon were hard. The Earth and the moon were hit by millions of asteroids (the reason for the moons craters) which brought important minerals to Earth. Along with this, it is believed that the asteroids brought water to earth. But another theory is that when the crust cooled down, steam was released, which condensates and turned into clouds which eventually rained and started making oceans, which would later be essential for life in earth. The impact of comets and the eruption of volcanoes created gases which created our atmosphere. It took millions of years for the oceans and atmosphere to form. The universe is 13.7 billion years old, and earth is only about 3 billion years old. This is just one of the many things which now inspire scientists to look for more answers. The Big Bang was an event which if happened just a little bit different we may have not been here. If our protosun had never compressed due to it's own gravity and sent thousands of tons of matter towards space we wouldn't be here. Even better yet, how lucky were we for all the matter joining and creating a crust which would make a planet in the perfect place for life to be formed. The chance that this would happen were very little but yet humans have taken control of Earth. It took billions of years to get the world to be like it is today and it will never quite be proven how the world was made so people are just going to have to rely on this theories. Bibliography http://www.wisegeek.com/how-was-the-earth-created.htm http://biology.clc.uc.edu/courses/bio303/bigbang.htm http://www.mcwdn.org/MAPS&GLOBES/Earth.html http://novan.com/solar.htm http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/971108a.html