The Big Bang Theory

Jamie L. Brock

Earth Science

Instructor Greg Hollmann

28 April 2016

“What is the Big Bang Theory?”

     You can go up to anyone throughout our world and ask he or she the age old question, “How was our Universe created?”  I guarantee that you will get an array of different answers, relevant to their ideas, theories or beliefs.  Each of us know that our universe exists, but this knowledge alone has not satisfied mankind’s quest for further understanding our universe.  Throughout the past centuries there have been many Cosmologists, Astronomers, Scientists, etc. who researched and gathered data to try and form a theory or make a theory stick.  However, there is only one theory that has a place in our society, which we know as The Big Bang Theory.  The Big Bang Theory was first suggested by a Belgian priest named Georges Lemaitre in the 1920’s, when he suggested that the universe began from a single primordial atom.  However, the big bang theory was born from the observations, which were done by Edwin Hubble and that other galaxies were moving from earth at a high speed in different directions.  This theory was then further boosted by the Arno and Penzias Wilsons discovery of cosmic microwave radiation, which is believed to be the tangible remnant leftover light from the big bang.  According to the big bang theory, the universe, all of its matter and radiation were compressed into a hot, dense mass, which was very minute.  The theory also states that there was an enormous blast, which enabled all of the universes matter and energy to spring from this small dense hot mass.  Once that matter had cooled down, new atoms were formed.  

Although Georges Lemaitre first proposed the Big Bang theory itself in the 1920’s (“Origins of the Universe”), people have debated over the creation of the universe since Aristotle was alive. Aristotle argued that the universe had an infinite past, which concerned Jewish and Islamic philosophers because this did not fit with their belief in creationism.  Many philosophers after Aristotle began forming arguments to support a universe with a finite past in response to his philosophy.  In 1225, Robert Grosseteste became the first person to try to describe the universe using one set of physical laws in his paper “De Luce” (Lewis).  Almost four-hundred years later, Johannes Kepler formed a new argument for a finite universe, using the dark night sky as proof. Soon after, Newton first came up with the idea of large-scale motion existing in the universe (Wolff).

In the early 1900’s Vesto Slipher and Carl Wirtz both separately observed spiral galaxies moving away from Earth.  Although they didn’t realize the implications, now this evidence is used to support the Big Bang Theory.  In 1915, Einstein proposed his general relativity theory.  This theory allowed for the idea of an expanding universe to be feasible (Takahashi).  Finally, in 1927 Lemaitre proposed that the universe began from a single atom that exploded and from there expanded outward (“Georges Lemaitre”).  Edwin Hubble’s observations of galaxies receding from Earth in every direction supported Lemaitre’s proposal, as did Arno Penzias and Robert Wilson’s discovery of cosmic microwave radiation.  After the Big Bang, some light was left over.  Scientists believe that cosmic microwave radiation is some of this leftover light.  It has been found all over the universe and is the oldest known radiation (“Origins of the Universe”). Hubble’s observations were revolutionary, and his observations have been credited with giving the most evidence to Lemaitre’s initial proposal (“The Big Bang”).  He discovered that the speed of the galaxies increases with their distance from us.  This discovery is now referred to as the Hubble Law (Wright).

Since Lemaitre first proposed the Big Bang theory, it has become the most well-known and accepted model for the creation of the universe.  Even today telescopes like the Hubble Space Telescope and the Spitzer Space Telescope are being used to continually check how the universe is expanding (“The Big Bang”).  According to Feuerbacher and Scranton, the best description of the Big Bang Theory is, “in the distant past, the universe was very dense and hot; since then it has expanded, becoming less dense and cooler.”  When they say expanded, they mean that space itself is expanding, and therefore the universe becomes less dense as it gets larger and the matter spreads out over a larger area.  However, a distinction must be made to show that the universe is not spreading into a preset volume; its expansion is completely self-contained.  Although it seems to contradict every-day knowledge of math and geometry, the equations produced by various scientists verify the assertion.  To understand how the universe itself can expand, read this excerpt from Feuerbacher and Scranton:  “An easier way to understand this concept is to think of it as the distance between any two points in the universe increasing…say we have two points (A and B) which are at fixed coordinate positions.  In an expanding universe, we would find two remarkable things to be true.  First, the distance between A and B is a function of time and second, the distance is always increasing.”