End Of The Universe
There have been numerous speculations on the final fate of the universe. The segment dealing with such fundamental questions about the universe is termed as Physical Cosmology. There have been at least a dozen fates which are predicted y rival theories. The notion that the universe was started with a Big Bang is now widely accepted by scientists. This acceptance made the question about the ultimate fate of the universe a matter of cosmological importance. The question concerns with the physical properties such as rate of expansion and average density of the universe. Albert Einstein’s formulation of the Theory of Relativity sparked off widespread curiosity about the fate of the universe. This is because General Relativity is something which can be used to describe the universe on a very large scale. The equations of Relativity can have many possible solutions, and each one of those solution predicted a different fate for the universe.
Challenging Theories
The evidential observation was first published by Edwin Hubble in 1929, his theory that the universe was continually expanding was based on his research and observation of a Cepheid variable star in faraway galaxies. George-Henri Lemaitre published the Big Bang theory back in 1931. However, Fred Hoyle challenged the big bang theory with his steady theory part which states that the universe continually expands but remains statistically unchanged due to the fact that new matter is continually created. The two theories challenged each other relentlessly until Arno Penzias and Robert Wilson published the cosmic microwave background radiation in 1965. This one cemented the authenticity of the big bang theory which became the most widely accepted view of the origin of the universe.
Density Parameter
Density Parameter denoted by Omega (?) is a vital parameter in deciding the fate of the universe. It is basically the average density of the total matter in the universe divided by a critical value of that density. The result is classified into three geometries based on whether they are less than 1, equal to 1 or greater than 1. These are referred to as flat, open and closed universes. If the main content of the universe is inert matter, as speculated by the 20th century dust model theories then there is a particular fate for each of the geometry. By measuring the value of Omega, cosmologists hope to ascertain the fate of the universe or the rate at which the expansion is decelerating.
Heat Death
Heat Death is a hypothesized final fate of the universe, in which it has run out of thermodynamic free energy and is rendered incapable of supporting life. The theory originates from the second law of thermodynamics which states that in an isolated system entropy goes on increasing.
Big Rip
The big rip theory states that there will be steady increase in Hubble Constant due to the continued acceleration of dark energy. The end is result is the disintegration of everything starting from the galaxies down to the smallest living form into elementary particles. The effect is brought about by phantom energy forces which rip everything in its path and shooting away from each other. As the dark energy density nears infinity the universe ends in a singularity, much the same way it was before birth.