The Death Of The Universe
What is the Universe?
The universe, never ending and eternal. Things are smooth here, literally- the universe is called a smooth homogenous soup, and there is nothing that would go wrong. Nothing that would potentially dangerous… right?
The universe is approximated to be some 13.8 billion years old. Our leading theory about the start of the universe is the theory of the Big Bang. A point sized, infinitely heavy sphere suddenly exploded, spewing matter across like never before (pun intended). This point is the single mother of space-time. However, even this seemingly immortal entity can perish. How? There are 4 ways actually, each one scarier than the rest. The universe’s fate depends on whether its expansion continues, accelerates or reverses.
The Big Crunch
This one is pretty cliché. It’s supposed to be the opposite of the Big Bang. Astrophysicists long thought “The Big Crunch” to be the most likely death of the universe. Outside our cosmic neighbourhood, we have observed every galaxy zooming away in all directions, a clear sign that the universe is expanding. If the Universe holds enough matter, including dark matter, the combined gravitational attraction eventually halts the expansion then precipitates to the ultimate collapse of the universe. All the galaxies, stars, planets, moons, are pulled together, -by the same force that caused an apple to fall on Newton- smashed, a raging inferno which won’t settle until the mass is compressed into a single point, and everything else is pure nothingness. Not the emptiness of space, but pure vacuum.
A universe that came from nothing in the big bang will disappear into nothing in the big crunch. Its glorious existence not even a memory
-Paul Davies
The Big Freeze
Though the Big Crunch sounds violently scary, our observations all agree that the universe will continue expanding forever. As everything moves farther and farther apart, the gases of dead stars disperse preventing new stars from forming. Eventually, galaxies stop growing and are secluded, alone in the universe. It’s a suffocation of all astrophysical activity, as fuel of growth ceases and the universe falls into a agonisingly slow cold eternal slumber.
(It is an end) marked by increasing isolation, inexorable decay, and an eons-long fade into darkness
-Katie Mack
The Big Rip
Well, the universe dies if it stops expanding or continues expanding in the same rate. So what happens when its expansion accelerates? You guessed it- it dies. This is a different form of death than Heat Death because while the celestial objects can no longer form and the universe becomes the coolest possible, in the Big Rip the dark matter accelerates the expansion, causing the universe to balloon so that even gravitational attraction can no longer hold it together. Then, things go downhill quickly. The galaxies, solar systems, celestial objects explode. Finally, the very atoms that the universe is made of is ripped apart.
The Big Rip is a scenario where, in the distant future, space itself is ripped apart by the expansion.
-Katie Mack
Vacuum Decay
Death by vacuum decay is an exception in terms that it is not in the ‘Big Three.’ Not only does it start with a word other than ‘Big’, it is also different because compared to the previous three, this type of death is not related to the expansion of the universe. This doomsday scenario is highly unlikely. A ‘true vacuum’ could form, owing to an instability in the Higgs Boson field. This might happen if a black hole evaporates the wrong way. This vacuum would accelerate at the speed of light, destroying everything, until it cancels the universe. In fact, it might have already begun, but we’ll never be able to tell till we’re gone
This could mean that the universe could undergo catastrophic vacuum decay, with a bubble of the true vacuum expanding at the speed of light. This could happen at any time and we wouldn’t see it coming.
-Stephen Hawking
There’s Time Left
After this huge talk of universal doomsday with nothing left to prove its existence, I think it’s my responsibility to inform that whatever the end looks like, it wouldn’t arrive for at least 200 billion years. That’s around 14.5 times the universe’s current age. Life on Earth however, will cease to exist as the Sun runs out of fuel and turns into a red giant in 5 billion years. We have time on our hands. Time to make amends. We must proactively deal with our problems, humans and nature both. Because if these astronomical catastrophes show us anything, it’s that we are small. However, we are special. We know, understand and can shape the world around us. As Katie Mack, the write of the book “The End of Everything (Astrophysically Speaking)” rightly said, we are “a species poised between an awareness of our ultimate insignificance and an ability to reach far beyond our mundane lives, into the void, to solve the most fundamental mysteries of the cosmos.”
We are just an advanced breed of monkeys on a minor planet of a very average star.
But we can understand the Universe. That makes us something very special.-Stephen Hawking
-Prem Naren
