English 102 Report
The Big Bang Theory
Table of Content
Big Bang Theory
At the beginning of the 20th century, physicists generally had a strong bias toward the idea that the universe was essentially unchanging. However ,this theory does not fit with the universe phenomena which change from minute to minute, and stars and galaxies might be born and die .In this report , we will look at one of the famous theories and greatest discoveries of this century .
1. What is the Big Bang Theory
The big bang is a theory which describes how our universe started . Many discoveries in physics and astronomy tell us that our universe in fact had a beginning .This theory became the most widely accepted theory that has come to dominate cosmology .(1:1),(3:1)
2. The beginning of the universe
According to the big bang our universe came into existence as a “singularity” about 13.7 billion years ago , but what is singularity? Singularities are zones which are thought to exist at the core of black holes. Our universe started as an infinitesimally small ,hot and dense point . Then it started to expand and cool until it reached the size and temperature of our current universe . It continues to expand and cool to this day and we are inside of it.(1:1)
2. History of Big Bang Theory
1. Edwin Hubble’s Discovery
In 1929 ,there was an incredible announcement that changed the world’s understanding of the universe . An astronomer called Edwin Hubble observed that every galaxy in the sky was moving away from us . The farther ones were moving faster than the nearby galaxies .They were heading out . What was happening ? Why is everything moving away from us ? It turns out that there is another explanation simpler and supported by many observations . The theory was that the entire universe is expanding . This explanation means that the observers in another galaxy should see exactly the same thing as we do . (2:1),(3:1)
2. Universe in The Past
How can we know the past of our universe ? The way to know that is to take the process of big bang theory in reverse .If we know that our universe blowing up like a balloon as time progresses , what would the universe look like in the past ? If the universe was smaller in the past , There must have been some point in time when the universe was half its current size. If you continue to run time backwards, there must have been a time when the universe was an infinitesimally micro-point .(3:1) 3. Major Evidence of Big Bang Theory
Big bang is very strong theory and almost all astrophysicists believes that big bang explains the origin of the universe. This is because all observations so far made support the Big Bang theory. Four main lines of evidence that are most-often used.
Red-shift of Galaxies
1. Redshirts of Galaxies
When you observe the light from a galaxy which is moving away ,the light will appear red because the light emitted from them has been shifted to longer wavelengths .However , If the light appears blue that means the galaxy is moving toward us .When astronomers observed the galaxies ,they saw almost every galaxy with red light. This means that the Universe is probably expanding.(1:2),(4:1)
Cosmic Microwave Background
2. Microwave Background
One of the strongest pieces of evidence that supports big bang theory is a Cosmic Microwave . At the early beginning of the universe , the whole universe was Significantly hot .As it expanded ,the heat remained as a glow and radiation .The big bang theory predicts that the glow and radiations exist and we should be able to see them as microwaves . In 1964 , a Cosmic Microwave was discovered by two astrophysicists which accurately measured it by using orbiting detectors . (4:1) 3. Mixture of Elements
According to big bang theory , our universe began with elementary particles .Next , these elementary...
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