Evidence For The Big Bang Essay Research

Evidence For The Big Bang Essay, Research Paper

Evidence for the Big Bang Theory:

Whether you happen to be walking down a neighborhood street on a starry night, or trekking across Canada in a car, or rising to the bright sunshine that beams through your bedroom window in the morning, many of us easily take it for granted, or perhaps it simply goes unnoticed that we are, human beings living on a planet called Earth; or that the beautiful stars in the sky have existed long before we did; or that our planet is but a tiny speck of sand in the grand Universe. Where did it all come from? many people before us have asked themselves. Scientists of Cosmology, who study large scale structures and the origin of the universe, have struggled with this very question and have developed several theories to answer just that. One such theory is called the Big Bang. It has become one of the most widely accepted theories of our time because in several ways, it provides tangible evidence to explain the origin of the universe. The Big Bang Theory assumes that the Universe began as cosmic singularity as small as an atomic nucleus which is infinitely small and infinitely curved and that all matter and energy were concentrated in a single point (Impey & Hartman, 513). This implies that the universe as an evolving model that existed in space-time, which began from an initial singularity and subsequently expanded (I&H, 513). Fundamentally, this theory tries to account for the physical events that took place in the very first moments during the creation of the universe, well over 15 million years ago. In much of the literature, it is evident that the three key pieces of evidence that support this theory include: the presence of cosmic microwave background radiation, galaxies are taking part in a universal expansion, as indicated by the linear relationship between distance and redshift, and the discovery of light elements (nucleosynthesis) in the universe s atmosphere that indicate the plausible event of a Big Bang (I&H, 513). Despite the contentions some scientists have with this theory for its inability to explain other phenomena, it remains today one of the most compelling theories used to explain how the universe came into being (http://liftoff.msfc.nasa.gov/academy /universe/b_bang.html).

In 1915, Albert Einstein developed his Theory of Relativity, which attempted to make his equations of relativity mesh with the incorrect belief that the universe was stable and static, with no beginning nor an end (http://www.bowdoin.edu/dept/physics/astro.1997/astro4/bigbang.html ). To recall, his Theory of

Relativity identified the relativity of gravity with that of the curvature of space-time, and from this theory, he yielded a static model of the universe. His failing however, was his account that the universe was static and unchanging, which was later challenged by meteorologist Alexander Friedmann, and mathematician Georges Lemaitre both of whom, without concrete observational evidence for universal expansion, individually discovered the solutions to Einstein s equations of gravitation which described an indefinitely expanding universe (http://www.bowdoin.edu/dept/physics/astro.1997/astro4/bigbang.html).

The first of the key pieces of evidence of the Big Bang, according to The Universe Revealed, is the existence of cosmic microwave background radiation. It is a diffuse isotropic radiation whose spectrum is that of a blackbody at 3 degrees Kelvin and is most intense in the microwave region of the spectrum (http://www.bowdoin.edu/dept/physics/astro.1997/astro4/bigbang.html ). Consequently, this cold, uniformly intense radiation can only be detected by radio telescopes. It is postulated that this radiation came from the cooled residue of the initial explosion from which the universe evolved (http://www.bowdoin.edu/dept/physics/astro.1997/astro4/bigbang.html ). What is interesting is that the scientist, George Gamow postulated the existence of this radiation even before the radio telescopes capable of detecting the microwave radiation were even created. Upon its discovery, scientists noticed its high degree of uniformity which proved its origin was from the farthest points of the universe, since any radiation produced near the sun, in our galaxy or nearby galaxies would be unevenly distributed (http://www.bowdoin.edu/dept/physics/astro.1997/astro4/bigbang.html). Furthermore, the cold temperature of 3 degrees Kelvin accounts for the notion that the universe was (and is) continually expanding, in that if the blackbody radiation was traced in time, it becomes hotter until it reaches the conditions to create blackbody radiation; a state of perfect equilibrium between radiation and matter (http://www.bowdoin.edu/dept/physics/astro.1997/astro4/bigbang.html). Quite remarkably, this background cosmic microwave radiation is tangible evidence of a cataclysmic event that occurred long ago.

The second major piece of evidence that supports the Big Bang Theory is the relationship between a galaxy s redshift and its distance, which was demonstrated by Edwin Hubble in 1929. Edwin Hubble was greatly influenced by the work of an astronomer, William de Sitter, who hypothesized in 1917 that “the universe possessed the peculiar property that the light from the most distant regions became progressively reddened as the distance increased” (http://www.bowdoin.edu/dept/physics/astro.19