The Big Bang
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The Big Bang
Why is the Universe expanding? What is Cosmic Back Ground Radiation (CBR)? There are many questions asked about our Universe, which we know so little about. Scientists, in their attempt to answer these and other confrontations, have found one idea that seems to explain much of what we don’t understand: The Big Bang Theory.
An explosion of incomprehensible speed was the beginning of our known Universe and existence. At that time matter as small as the head of a pin inflated to become larger than the visible Universe of today in less then one millisecond. The newly born Universe cooled very quickly and continued to grow. Still, the heat was too great for normal elementary particles like protons and neutrons to be bound together. Instead, the particles were in their free form and were called quarks. These quarks and the massive amount of radiation released form the explosion made up most of the Universe in the first microsecond.
Within the quarks, matter and antimatter (elementary particles such as protons and electrons, yet with an opposite charge) was distributed in a 2:1 ratio. The matter and antimatter soon began to cancel each other out, for antimatter and matter cannot coexist in close range for more than a few seconds without annihilating each other. Because the matter had more particles then the antimatter, there was a little residue left over. It was this leftover debris that created the galaxies, the stars, the planets, and even you and me.
At this point the Universe was one second old, and it began fusing lighter elements like helium. This nuclear activity only lasted a few minutes, but it is one of the reasons the Universe has an abundance of light elements.
The Universe continued to grow and cool, later fusing the heavier elements and then what we see around us today. All of it began at the Big Bang.
The Big Bang is a well known and believed theory of how the universe was created. It is described as a tremendous explosion that has a certain place and time. In fact, the Big Bang is considered to be the beginning of time as well as the beginning of the universe.
Scientists today, don’t know what happened before the Big Bang. However, they have concluded that if something had happened, it would not have effected the explosion in any way. Most have agreed that what ever there was, or wasn’t before the Big Bang, has no importance and it should be left out of the scientific model of the universe. The Big Bang is therefore considered the beginning of time.
There were many people who worked together to come up with the present theory of creation. Edwin Hubble, Arno Penzias, Robert Wilson and Alan Guth all contributed greatly to the formation of the Big Bang theory.
Edwin Hubble used his large telescope to see far away stars and galaxies. He knew that the elements in the stars reflected back specific colors, and you could tell what a star was made of by its color “DNA”. Hubble noticed that this pattern had been slightly shifted to the red side of the spectrum, otherwise called a red shift. He knew, based on the Doppler effect, that a red shift was caused by the stretched wavelengths of an object moving away from a point. If the galaxies he had observed had shifted to the red side then it meant that they were moving away from Earth. He also discovered that the galaxies were moving away from each other, as well.
With these observations in mind, Hubble announced that the universe was expanding. He then came to this syllogism: If the universe is expanding, then at one point it was smaller. The result of his postulations was the Big Bang theory.
Another mystery of the universe was the Cosmic Background Radiation (CBR). CBR is made up of photons throughout the universe that are floating for no apparent reason in space. Arno Penzias and Robert Wilson spent their lives trying to explain the origin of this radiation and why it is still existent today. Their discoveries led them to an idea similar to the Big Bang theory. They were able to prove that the radiation could only result from a huge explosion as great as the Big Bang and that the radiation had at one point dominated the Universe. Although the two scientists measured the CBR’s temperature to be 2.73 degrees above absolute zero, they found that at the time of the Big Bang it was 3000 Kelvin and very bright. However, as the Universe expanded, so did the radiation, causing the radiation to stretch and in turn slowly grow weaker. The most important aspect of the discoveries about the CBR was the fact that it supported