What is the Big Crunch?
The Big Crunch is a theory brought forward by scientists to suggest a time will come when the expansion of the universe is stopped and reversed. Basically it means all matter in the universe that was created reverts back into the gravitational singularity from which it first originated. At this point, time would come to a halt. This theory in general is mainly based on Albert Einstein's Theory of General Relativity.
Many scientists are confronted with the question whether the universe will carry on expanding or maybe not, or whether it will begin contracting at a certain point in the years ahead to come. Galaxies such as Andromeda, which is closest to Earth, emit a blue shift rather than a red shift. This in fact tells you that they are moving towards our galaxy the Milky Way, and when an object approaches an observer, it emits a blue shorter wave. This may be one particular reason why these galaxies are moving towards us because gravity is more than strong enough to overcome the recession of nearby galaxies.
This is why the Big Bang theorists believe that this blue shift may be the indication that the Big Crunch will happen in the future and cause the universe to end in one biscuit like crunch.
However, the Big Crunch theory isn't that simple, there is complications for this to occur. This theoritical event requires a certain density of matter and energy to actually reverse the expansion of the universe. This is known as the 'critical density'. Scientists believe that matter and energy were not created in the Big Bang theory, therefore the universe was as dense as it was ever going to get at the time of the Big Bang. Experts are attempting to calculate the density of the universe to examine whether it is above or below the critical density.
Calculations made recently gave an idea that the universe may be less dense than the assumed critical density. This means that the universe will never stop expanding and will continue expanding for eternity. However, scientists have some difficulty in resolving in dark matter and energy when calculating the density of the universe, therefore the unlimited expansion or the Big Crunch both stay as distinct possibilities. Dark matter is usually all the matter in space floating about and is very difficult to see and makes up over 95% of all the mass in the universe according to scientists. The 'dark energy' may be the reason why the universe is expanding but scientists are still baffled by it because it has an effect on other objects in space. This unknown entity is widely believed to push galaxies farther apart, but it's only an assumption on this mysterious dark energy.
Some experts in the Big Crunch field believe in the theory that the whole process might repeat itself as soon as the universe has contracted. Therefore, it might be likely that another Big Bang will occur. If this is true, then this theoritical Big Bang and Big Crunch process could have happened thousands of times before and the universe which we inhabit is only one of a sequence of several universes of the entire structure.
Other Universe-Ending Theories
The Big Freeze, Big Rip, Big Change and Big Slurp are other scenarios to suggest the universe will end in such manners. However the Big Freeze after the Big Crunch theory, seems more convincing than the rest of the other scientific theories put forward.
What is the Big Freeze?
Big Freeze is also known as the Big Chill or Heat Death. The Big Freeze was put forward by scientists and stating that the universe will continue to expand to a certain point where there will be no more space for heat to exist. Nor will there be room for usable energy. This means when the universe is expanding rapidly and dispersing heat in space, the galaxies, planets and stars will be dragged even farther from one another. Everything in space will be extremely far away that no light will be able to reach from the stars and galaxies.
Everything will be isolated and empty without light in the universe. It is like staring up at the night sky on earth and nothing is there. Stars wont be able to form due to lack of light from other space materials which is required for star formation. Eventually, all objects in the universe will continue to get colder until the temperature reaches minus zero and everything stops. It will appear as if the universe is full of frozen galaxies, planets and dead stars due to starvation of heat energy. Basically, the Big Freeze theory may be the scenario of how the universe will end whilst it is still there in a frozen state.
- The Formation of the Universe
Fifteen thousand million years ago the Universe suddenly came into existence in a tremendous explosion which is called the Big Bang. The gases rushing outwards from this explosion eventually turned into galaxies, stars and planets, including the Milk
BRENDA ARLEDGE from Washington Court House on June 13, 2020:
I would hate to stare up at the night sky and see no stars or light.
The big bang and other Cosmo things are interesting.
Thanks for sharing.
John Welford from Barlestone, Leicestershire on January 08, 2019:
These are fascinating speculations, with cosmologists having a whale of a time coming up with conflicting theories!
Zia Uddin (author) from UK on December 07, 2018:
Thanks a lot for visiting.
Mohan Babu from Chennai, India on December 07, 2018:
I too believe that Big Bang and Big Crunch are stages in the never ending cycle of events in this Universe.