Foundation of modern cosmology
Cosmology being the study of the universe has been changing over the years to what we currently view it as. Modern cosmology has been founded on the works of various principals who have studied astrology over time and during different eras.
The ancient European medieval and ancient Greeks believed the earth to be the at the universe’s center. They believed that the moon, planets, and sun were orbiting the earth. This idea was believed by many including the Catholic Church who in fact influenced people of their religion to believe so. The Catholic Church banned anybody from thinking against that line claiming that it would be questioning God. An example is when the Catholic Church almost killed Galileo for such claims. It was not until the 16th century that a new notion came to light. This new idea claimed that the earth and other planets were the ones that were orbiting the sun. Therefore, in the cosmic system the sun is centrally positioned. Nicholas Copernicus is the one who came up with this idea in his book “On The Revolution of the Heavenly Spheres.” (Hawley, Holcomb, 2005, pg. 27)
Earlier in the 17th century, Johannes Kepler, a German scientist developed further Copernicus’s concept which was that of a universe that is heliocentric (Hawley, Holcomb, 2005, pg. 28). We owe keplerthe discovery of planets revolving in ellipses around the sun. He mathematically describes in his three planetary motion laws that planets do so. Furthermore he suggested that a force from the sun keeps them in orbit. Isaac newton later through his law of gravity proved that Keplers same force also enabled the orbiting of the moon around the earth. Therefore, one striking universal force unites earth and the heavens.
All three founders were not only scientists but also religious. They viewed the heavens from the point of the theology they had. Newton once said that he wrote the solar system from a point of view that will go in line with the deity’s belief and it will please him if it served that purpose.
The Big Bang theory
It states that the universe came into existence about 13.7 billion years ago due to singularity. Singularity are areas that we think exist at black hole’s cores. After the universe appeared it is said to have swollen, expanded, and cooled which made it change from the small size and hotness it had to the current universes’ temperature and size (Hawley, Holcomb, 2005, pg. 38). It continues to expand and contract while cooling to this very day. This led to the formation of one big star that is surrounded and clustered with many other billion stars in the galaxy.
The cosmic microwave background information (CMB) is an experiment conducted to prove the theory. It Arno and Robert worked with a receiver from a microwave. From every direction they pointed they got noise and it came from the sky at a frequency that was the same. The radiation in the background is the remnant of a universe that was hot (Hawley, Holcomb, 2005, pg. 46).
Structure of the Milky Way and dark matter’s influence on it
Structure of Milky Way
Milky Way’s structure resembles that of a normal large spiral system. It is divided into different parts as explained below.
Galactic center (nucleus)
It is composed of a radio source that is intense called Sagittarius A. movement of materials round this source suggest that it contains a huge object that is compact. This concentration is explained best as a black hole that is supermassive that is about 4 billion times the suns mass. It also has a galactic bar that contains stars of red clumps that delineate it. A 5-kpc ring may surround the bar and it contains molecular hydrogen of a bigger fraction (Hawley, Holcomb, 2005, pg. 108).
Central bulge
It surrounds the nucleus. It is a bulge of stars that extends and is almost spherical in shape. This contains population II stars, comparatively it is rich elements that are heavy. Clusters of a number of similar globular stars are variegated with stars (Hawley, Holcomb, 2005, pg. 112). The bulge can be optically viewed when it rises above the dust that obscures which comes from the galactic plane.
The disk
It is the most visible part of the galaxy extending 75,000 light years from the nucleus. The disk is underlying to the stars body where the arms of the Milky Way are superimposed. Its thickness is estimated at 1/5 of its diameter, although thickness varies with different components. The thin disk is the thinnest with young stars, gas, and dust. The thick disk component contains the older stars (Hawley, Holcomb, 2005, pg. 120).
The dark matter is responsible for the great gravitational force the Milky Way has. Reason being it is equivalent to 5 times the mass of ordinary matter. The dark matter’s gravitational influence makes the Milky Way to have a warp that is pronounced (Hawley, Holcomb, 2005, pg. 126). In relation to what is explained, the dark matter amplifies the gravitational effect that orbiting satellite galaxies have when it comes to distorting the galaxy.
Dark energy
In the year 1998, dark energy was discovered by teams of two astronomers who were measuring light that was coming from stars that explode called Type IA supernovae or standard stars.
Theory of everything
Theory of everything is an alleged theoretical physical theory that links together and explains fully all physical phenomena that are known, it forecasts outcomes of experiments of any type that can be conducted in principle (Universe Today, 2013). This theory brings together quantum field theory and general relativity which explains spacetime (large-scale structure) and gravity (Universe Today, 2013).
The theory of everything tries to explain all what is happening in the universe by linking all the four forces. It has found out that phenomena in the universe have their bases on common assumptions and set of rules. Therefore, it gives us a better understanding of the universe.
References
Hawley, J. F., & Holcomb, K. A. (2005). Foundations of modern cosmology (2nd ed.). Oxford [etc.: Oxford University Press.
The Theory of Everything. (n.d.). Universe Today — Space and astronomy news. Retrieved May 9, 2013, from http://www.universetoday.com/85737/the-theory-of-everything/
