1) Write a composition explaining the origins of our Universe, using the followi
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Question
1) Write a composition explaining the origins of our Universe, using the following terms in your narrative. Do not copy/paste from Internet sources, and use boldface or capitalized letters:
a - Big Bang
b - The lack of symmetry between matter and antimatter
c - cosmological inflation
d - cosmological nucleosynthesis: formation of hydrogen and helium
e - Recombination era
f - the WMAP and its findings
g - 72 Km/s/Mpc
2) Explain all key elements of the Big Bang Theory, listing its major supporting data and naming some of its successful predictions, such as those confirmed by the Wilkinson Microwave Anisotropy Probe. Indicate all evidences supporting such theory.
Explanation / Answer
1) Our universe is 13.7 billion years old, but astronomers are peering deep into its history and are getting a greater understanding of how the first stars formed, and how the earliest galaxies came together. See images, illustrations and diagrams of the universe from now back to the Big Bang. Even the amount of matter in the universe, can be different to what it was before the Big Bang, as the Law of Conservation of Matter, will break down at the Big Bang. Since events before the Big Bang have no observational consequences, one may as well cut them out of the theory, and say that time began at the Big Bang. The Big Bang should have created equal amounts of matter and antimatter in the early universe. But today, everything we see from the smallest life forms on Earth to the largest stellar objects is made almost entirely of matter. Comparatively, there is not much antimatter to be found. Something must have happened to tip the balance. One of the greatest challenges in physics is to figure out what happened to the antimatter, or why we see lack of symmetry between matter and antimatter. In 1980, to explain the conditions observed in the universe, astrophysicist Alan Guth proposed cosmic inflation. The term inflation refers to the explosively rapid expansion of space-time that occurred a tiny fraction of a second after the Big Bang. In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 1036 seconds after the conjectured Big Bang singularity to sometime between 1033 and 1032 seconds after the singularity. The first nuclei were formed about three minutes after the Big Bang, through the process called Big Bang nucleosynthesis. It was then that hydrogen, helium and lithium formed to become the content of the first stars, and this primeval process is responsible for the present hydrogen/helium ratio of the cosmos. When the universe was younger than about 300,000 years, the temperature was high enough that all of the hydrogen was ionized, that is the electrons were free and separate from the protons. Because of the presence of the free electrons, photons were scattered around in all directions and could not travel far before changing their direction. Therefore the universe was "opaque". When the universe cooled to about 3000 K, the electrons and protons combined to form hydrogren atoms. After "recombination era", photons were able to travel through the universe relatively unimpeded, and the universe became "transparent". he Wilkinson Microwave Anisotropy Probe (WMAP) is a NASA Explorer mission that launched June 2001 to make fundamental measurements of cosmology -- the study of the properties of our universe as a whole. WMAP has been stunningly successful, producing our new Standard Model of Cosmology. WMAP's data stream has ended. Hubble's law is considered the first observational basis for the expansion of the universe and today serves as one of the pieces of evidence most often cited in support of the Big Bang model. The motion of astronomical objects due solely to this expansion is known as the Hubble flow. The Hubble constant for the expansion of the Universe is 72 km/s/Mpc right now.
2) The expansion of the universe
Edwin Hubble's 1929 observation that galaxies were generally receding from us provided the first clue that the Big Bang theory might be right.
The WMAP spacecraft measured the basic parameters of the Big Bang theory including the geometry of the universe. If the universe were flat, the brightest microwave background fluctuations (or "spots") would be about one degree across. If the universe were open, the spots would be less than one degree across. If the universe were closed, the brightest spots would be greater than one degree across.
The abundance of the light elements H, He, Li
The Big Bang theory predicts that these light elements should have been fused from protons and neutrons in the first few minutes after the Big Bang.
The WMAP satellite is able to directly measure the ordinary matter densityand finds a value of 4.6% (±0.2%), indicated by the vertical red line in the graph. This leads to predicted abundances shown by the circles in the graph, which are in good agreement with observed abundances. This is an important and detailed test of nucleosynthesis and is further evidence in support of the Big Bang theory.
The cosmic microwave background (CMB) radiation
The early universe should have been very hot. The cosmic microwave background radiation is the remnant heat leftover from the Big Bang.
he existence of the CMB radiation was first predicted by Ralph Alpherin 1948 in connection with his research on Big Bang Nucleosynthesis undertaken together with Robert Herman and George Gamow. It was first observed inadvertently in 1965 by Arno Penzias and Robert Wilson at the Bell Telephone Laboratories in Murray Hill, New Jersey. The radiation was acting as a source of excess noise in a radio receiver they were building. Coincidentally, researchers at nearby Princeton University, led by Robert Dicke and including Dave Wilkinson of the WMAP science team, were devising an experiment to find the CMB. When they heard about the Bell Labs result they immediately realized that the CMB had been found. The result was a pair of papers in the Astrophysical Journal (vol. 142 of 1965): one by Penzias and Wilson detailing the observations, and one by Dicke, Peebles, Roll, and Wilkinson giving the cosmological interpretation. Penzias and Wilson shared the 1978 Nobel prize in physics for their discovery.
These three measurable signatures strongly support the notion that the universe evolved from a dense, nearly featureless hot gas, just as the Big Bang model predicts.
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