From ancient days man has wondered how was it that the universe came into being? This was one of the most important questions asked by man ever as it could solve many problems such as how humans had come into existence were there any alien life possible…etc However any equally important question that runs in parallel with this one is that how will the universe end. This question as you might have already guessed has no certain or definite answer because there are a million ways this could go down. However after years of research scientists have come up with the three most likely ways that the universe will go down in
- The Big Rip-
Dark matter is a substance, of which very little is known, is a substance that permeates the universe. It is believed that it is due to this dark matter that our Universe is ever expanding and that too its expansion is accelerating by the second. Right now the gravity that holds together stars with their planets in position or even entire galaxies in place is much stronger than the force of the expanding Universe.
However it is hypothesised that after billions of years we will reach a point in time that the force of expansion will overpower the gravity holding everything in place this will have catastrophic effects on everything initially only galaxies will be pulled apart followed by the destruction of black hole, stars and planets (effectively wiping out human existence) The event will be quite literally the big rip. Imagine the space as a rubber band as you keep pulling it apart it keeps expanding up to a certain point after which it just snaps. Although this isn’t the best analogy you get an idea of how we go down in complete ‘coldness’.
- Heat Death-
Everything in our universe aims to attain the highest entropy possible. What this means is that every substance tries to be as disorderly as possible. In the universe context it will be a good idea to think about a hot cup of coffee which keeps cooling down until it reaches the temperature of its surrounding environment. Similarly in our expanding universe every substance will over a very large but finite period of time turn into energy. This will mean that nothing in our universe exists from the Sun to the Earth everything has been converted to energy. This process is basically the disintegration of everything that is present and is most likely to occur.
- Big Crunch-
One of the most unlikely ways that the universe could end is the Big Crunch. If our initial hypothesis of the amount of dark matter was wrong or dark matter vanishes over time then gravity will be the dominating factor in the universe causing an implosion this will basically lead everything to collapse on its own. The temperatures reached during this scenario will be extreme and the highest that have been recorded and finally an implosion to finish off everything there is left.
On a more positive note there is a lot of time that is left (billions and billions of years) before any of these scenarios occur so we can kick back and relax till then.