The Big Bang
For decades the Big Bang theory has been the leading theory on the beginning of our universe. Alternate theories come and go, but mainly go. As new data and research are continually eliminating alternatives to the standard model of cosmology, the Big Bang just keeps getting stronger. Before discussing the alternate theories to the Big Bang theory, the basics of the early universe should first be understood. The main points opposing the theory are based around a few aspects that will be defined in the explanation of the early universe. These points include inflation, dark matter and dark energy, the cosmic microwave background (CMB), and red shift. The theory states that the universe sprung from a singularity an infinitely dense point. A process called inflation took over from there, and all the matter expanded exponentially from one very small point to something the size of a basketball in a fraction of a second. Inflation is very important to the Big Bang theory, as it is required to explain the uniformity of particles in the very early universe, among other problems. The inflation period ended, but the expansion continued, and continues today. Expansion will be discussed further later. The Big Bang theory cannot be proven through visual observation. Most people are aware that the light from an object 3 million light years away will take 3 million years to reach the Earth. In this way, scientists can "look" back in time to see far into the history of our universe. This is limited, however, as at one point the universe was dark. Even the most powerful telescopes of the future will not be able to look into the first billion years of our universe. Adam Frank (2006) describes this early, and dark, period of our universe in his article describing the "First Billion Years." According to the Big Bang theory, (and Frank), immediately after the initial event and inflation took place, our universe was a consistent and smooth "soup" of particles. Radiation and matter were tightly bound. Matter that is radiated is known as "ionized" matter. Photons were constantly being absorbed and reemitted by this ionized matter. Photons are defined by Paul Shestople as "Particles which are packets of light" (1997, Glossary, P-T, para. 3). Because photons could not roam freely during this time period due to the ionized matter, this is the known as the dark ages of the universe. About 380,000 years later, this hot soup cooled enough to allow electrons and protons to come together to form hydrogen (Frank, 2006). As the hydrogen was created, matter, radiation, and light could go their separate ways. It was at this time that the CMB came into being. The CMB is defined by Shestople as "Obeservable radiation
left over from the Big Bang" (1997, Glossary, A-E, para. 14). The CMB is the radiation that was freed as the first atoms were formed. At this same time, photons were also freed. As Adam Frank (2006) describes, the hydrogen in its neutral (non-ionized) state did not absorb photons as we know them in the CMB, but visual and ultraviolet (UV) light were still absorbed. "The current dominance of ionized hydrogen is one reason we can see so far with optical telescopes. The Dark Ages were the epoch of cosmic history between the initial formation of neutral hydrogen and its eventual destruction" (p. 30). Before the universe could clear to all types of photons, the hydrogen needed to be re-ionized. Scientists call this re-ionization, but this is actually the first time the hydrogen was ionized since its formation. How was the neutral hydrogen ionized? The first answer is gravity. Dense regions drew in more matter, and became denser. As the hydrogen clouds gained more and more density, they eventually ignited into huge stars, far larger than the stars we know in our galaxy today. "
These first stars were, on average, gigantic at least 25 times as massive as the sun and ranging as much as 100 times as massive, if not more" (Lemonick,...
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Chown, M. (2005, July). End of the beginning: Is it time to admit that the idea of a big bang just doesn 't stack up? Marcus Chown meets the doubters thinking the unthinkable. New Scientist, 187, 30(6). Retrieved December 26, 2006, from Thomson Gale database.
Frank, A. (2006, June). The first billion years: After the release of the cosmic microwave background, darkness fell over the cosmos. (cover story). Astronomy, 34.6, 30. Retrieved January 14, 2007, from Thomson Gale database.
Gaastra, E. (2005, October). Is the biggest paradigm shift in the history of science at hand? Progress in Physics, 2005.3, 57(4). Retrieved December 20, 2006, from Thomson Gale database.
Lemonick, M. (2006, September). Let there be light. (cover story). Time, 168.10, 42(7). Retrieved January 14, 2007, from EBSCOhost database.
Shestople, P. (1997, December). Big Bang cosmology primer. Retrieved January 2, 2007, from http://cosmology.berkeley.edu/Education/IUP/Big_Bang_Primer.html
Griswold, B., & Hinshaw, G. (2006). WMAP cosmology 101:Matter in the universe. Retrieved February 2, 2007, from NASA, WMAP website: http://map.gsfc.nasa.gov/m_uni/uni_101matter.html
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