The Big Bang Theory

The Big Bang Theory is the recognized hypothesis on how the universe came into existence.  It is the most accepted answer to the question, “How did the universe came into being?” This research paper aims to discuss the definition of the theory, its history and the proofs that validate the theory.

            The Big Bang Theory presupposes that there was a moment where nothing existed (“Overview,” 2008; Shestople; 1997).  The beginning of the universe was said to have occurred roughly 13.7 billion years ago (“Overview,” 2008; “Creation,” 2002; Pasachoff, 2007).  It all began with what is called a singularity (“Overview,” 2008; “Creation,” 2002; Shestople; 1997).  Astrophysicists thought that singularities were created through “vacuum fluctuation” (Shestople; 1997).  Singularities are actually “zones of infinite density” (“Overview,” 2008).  What would eventually become the universe was condensed in an atomic nucleus (“Creation,” 2002).

This nucleus was minute in size, but it was very dense and hot at the same time (“Overview,” 2008; Pasachoff, 2007).  This compact and dense nucleus exploded, and the explosion in turn created the universe (“Overview,” 2008; “Creation,” 2002; Pasachoff, 2007; “Four Pillars,” n.d.).  After the explosion, the particles separated from each other; it was gravity that brought them together (Shestople, 1997).  As a result, galaxies were created, and this happened in a short span of time.  Aside from galaxies, other matter, such as energy, space and time, were created as well (“Creation,” 2002).  After the explosion, the universe expanded and cooled (“Overview,” 2008; Pasachoff, 2007).  At present, it is believed that the universe is still expanding (Shestople; 1997).

            The theory initially arose from what is referred to as field equations (Pasachoff, 2007). These are mathematical equations of Albert Einstein in his Theory of Relativity in 1915 (Pasachoff, 2007).  Many scientists have formulated solutions for the equations posed by Einstein.  These include Belgian Georges Lemaître and Dutch Willem de Sitter and a physicist from Russia named Alexander Friedmann.  They all presented different views of the universe.  For Lemaître, the universe originated from a “primeval atom” (Pasachoff, 2007). The second law of thermodynamics was the basis for his study (“Creation,” 2002).

Due to the singularity, he believed that the nucleus disintegrated, and in turn resulted in numerous elements.  His theory of the universe was published in the journal entitled Nature on May 9, 1931 (“Creation,” 2002).   In essence, his cosmological theory did hypothesize the expansion of the universe.  De Sitter, on the other hand, did not have matter in his universe (Pasachoff, 2007).  In 1922, Alexander Friedmann created the solutions for the Einstein’s equations.  He believed that the universe also expanded from a “clump of matter” (Pasachoff, 2007). It was Friedmann’s contribution that was the foundation of the big bang theory.

            In 1929, Edwin Hubble, an American astronomer, also contributed to the big bang theory through his discovery regarding redshifts of light (Pasachoff, 2007).  The same astronomer was able to discover that another galaxy existed outside Milky Way; it was called Andromeda (“Creation,” 2002).  From this discovery, Hubble was able to determine a link between the distance of the galaxies and their velocities.  Soon after, it was also discovered that galaxies were moving farther apart (Pasachoff, 2007).

It was also Hubble who discovered that the farther the galaxy, the faster they moved.  This is the proof, presently known as Hubble’s Law, that the universe is undergoing a uniform expansion (“Overview,” 2008; Pasachoff, 2007).  During the 1940s, a Russian-American physicist named George Gamow formulated a theory that agreed with the solutions Friedmann provided.  A decade after, Fred Hoyle, an astronomer from Britain, formulated his own theory in opposition with Gamow’s; he called it the steady-state theory.  It was Hoyle who coined the phrase “big bang,” and it was the term used ever since.

            It all began with Albert Einstein. He had recently developed his Theory of Relativity, and he sought to understand the nature of the universe (“Creation,” 2002).  In the beginning, Einstein thought that the universe was static (“Creation,” 2002; Pasachoff, 2007).

  However, his computations resulted in the opposite; the findings hinted that the universe can and did expand or contract.  Nevertheless, Einstein still insisted that the universe was stable.  The equation was later changed to fit his belief; a cosmological constant was included in the equation.  This would render the universe as a closed entity, as opposed to an expanding one (“Creation,” 2002). Later, when the expansion of the universe was verified, Einstein was forced to acknowledge his fault in adding a cosmological constant in the equation (Pasachoff, 2007).

            The Big Bang Theory is the only hypothesis which offers a suggestion on how the universe was created.  The creation was believed to have occurred so fast that the universe was fashioned at an estimated 10^-43 seconds after the explosion (“Creation,” 2002; Pasachoff, 2007).  The universe originated from a force, which eventually was identified as other forces at present (Pasachoff, 2007).  This includes “gravity, electromagnetism and both strong and weak nuclear forces” (Pasachoff, 2007).

            Inflation plays a big part in one of the recognized versions of the Big Bang Theory (Pasachoff, 2007).  The theory that involves inflation describes that the universe was inflated at approximately 10⁵⁰ times the original size in 10^-32 seconds (Pasachoff, 2007).

Soon after, the inflation of the universe slowed down.  This version upholds that after the first period of inflation had occurred, it is followed by a continuous but slow expansion.  Moreover, the inflation model states that at present, the universe is on the verge of either being open or closed.  This version was introduced in the 1980s, and its supporters included cosmologist Alan Guth and astronomer Paul Steinhardt from America, scientist Andrei Linde and an astronomer from Britain named Andreas Albrecht (Pasachoff, 2007).

            There are evidences that support the feasibility of the Big Bang Theory.  The first of these evidences came from Americans Arno Penzias and Robert Wilson (“Overview,” 2008).  In 1965, both men have found a 2.725 degrees Kelvin cosmic microwave background radiation which affects the universe (“Overview,” 2008).  That temperature is equal to

-454.765 degree Fahrenheit or -270.425 degree Celsius (“Overview,” 2008).  It was said that a million years after the explosion, the temperature of the universe had reached 3000°C or 5000°F due to cooling (Pasachoff, 2007).  At that point, protons and neutrons merged to create hydrogen atoms.  These atoms only have a capacity to “absorb and emit certain wavelengths of light” (Pasachoff, 2007).

The creation of the said atoms made the other wavelengths of light, especially those which hampered free electrons before the cooling of the universe, to travel farther.  It was this change that caused the radiation that can be measured at present.  Because of the discovery of cosmic radiation, Penzias and Wilson received a Nobel Prize for Physics in 1978 (“Overview,” 2008).

            In addition, there is much evidence from the efforts of the National Aeronautics and Space Administration, or NASA (Pasachoff, 2007).  A spacecraft called the Cosmic Background Explorer, or COBE, traced the background radiation of the universe from 1989 to 1993 (Pasachoff, 2007).  Through the spacecraft, it was discovered that the distribution of the radiation was compatible to the matter that releases radiation because of the temperature. This result worked in favor of the Big Bang Theory; it is because the findings supported that the radiation varies.  These variations probably originated from the growth of the galaxies (Pasachoff, 2007).

            At present, the Big Bang Theory is still questioned.  However, there are substantial evidences that prove it did occur.  Still, it remains the most accepted theory in the creation of the universe.

References

AllAboutScience.org. (2008). Big bang theory – an overview.  Retrieved April 5, 2008, from http://www.big-bang-theory.com/

Creation of a cosmology: big bang theory. Retrieved April 5, 2008, from http://ssscott.tripod.com/BigBang.html

Pasachoff, J. (2007). Big bang theory. Microsoft Encarta Online Encyclopedia.  Retrieved April 5, 2008, from http://encarta.msn.com/encyclopedia_761570694/Big_Bang_Theory.html

Shestople, P. (1997). Big bang cosmology primer. Berkeley Cosmology Group. Retrieved April 5, 2008, from http://cosmology.berkeley.edu/Education/IUP/Big_Bang_Primer.html

University of Cambridge. (2005). The four pillars of the standard cosmology.  Retrieved April 5, 2008, from http://www.damtp.cam.ac.uk/user/gr/public/bb_pillars.html