Let’s talk about Global Warming, on a solar system scale. The Sun’s luminosity increases by 6% every billion years. Now 6% may not sound like a lot, and a billion may sound like a lot, but this change is huge. It is enough to obliterate life on Earth as sun will become a red giant and gobble up Mercury, Venus and maybe, just maybe, Earth. Universe, on the other hand, can end in one of four ways.
The Big Rip
It’s no secret that our universe is expanding. It is expanding, and expanding fast. Not just, it’s accelerating too. All the planets and all the stars live in harmony, tied together with force of gravity. Enter Dark Energy. Turns out, it makes up three fourths of this entire universe. And that isn’t even why it’s our biggest enemy. Scientists don’t know anything about it, apart from knowing it exists! The rate of expansion increases every year – it will continue indefinitely, until all the galaxies, planets, stars will no longer be able to hold themselves together. This theory is called Big Rip.
This is the complete opposite of The Big Rip. A hundred billion years from now, if universe lacks the repulsive energy of expansion, gravity will stop it altogether and the whole universe will close onto itself to form a final singularity. This collapse is known as “The Black Hole Era” too. At first, this contraction would be slow and steady, almost as if it isn’t even happening. Then, as the temperature gradually increases, stars will explode and vaporize into atoms and nuclei. This is Big Bang, in reverse. The process speeds up and soon it becomes wildly chaotic. So, the feeble gravity we so easily look down upon is capable of ending this cosmos. Cool, huh?
The Big Freeze
Counter-intuitively also called “Heat Death”, Big Freeze ends with the whole of cosmos freezing, to death. It is a direct consequence of an ever-expanding universe. It is by far, the most acceptable model of the future of Universe. In an isolated system, the entropy keeps on increasing until it reaches a maximum value. The moment this happens, all heat in this universe will be distributed evenly. For any process to occur, there must be a heat difference. When this ceases, the universe ceases to exist. Mechanical motion within the system would no longer be possible
The Big Slurp
Ever cringed at somebody’s slurrrping? It has the same effect as ending a universe. It’s that powerful. Seriously, stop it. When Higgs Boson was unearthed at LHC in July 2012, Scientists were overjoyed. But with Higgs Boson, came another theory of the end of the universe. Imparting a certain mass to this particle means that our vacuum is unstable, existing in a metastable state until now. The vacuum will decay and it will be a gruesome death According to a Michael Turner and Frank Wilczek paper in 1982
Without warning, a bubble of true vacuum could nucleate somewhere in the universe and move outwards at the speed of light, and before we realized what swept by us, our protons would decay away
What’s sad, isn’t the fact that the universe is going to end. The trouble is, we won’t be around to see it go. We might still have a couple billion years, but it still is sooner than a forever. Make your time worthwhile because one lifetime is all we have.