ENC1101 Mon-Wed 9:30-10:45am
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...