“The universe is everything; all space, all time, all matter.”
The universe is a mystery. It has been for the past 14 billion years, from its conception to what it is now. It’s an infinite space, with violent battles constantly raging since its birth. Formation of stars and planets are anything but pleasant. Don’t fret, because the universe is currently in its prime and its death is something that we won’t have to worry about experiencing first hand. We’re a long way from the ultimate destruction of space and time.
Despite being a little over 13 billion years old, the universe is still growing. Obviously, we can’t pinpoint exactly when it’ll end but scientists have created a very plausible theory in which it’d simply exhaust its remaining energy and result the universe into a desolate, heat-less space. This theory – named the Big Freeze – remains to be the most legitimate one because it is a ‘direct consequence to an ever-expanding universe’. Makes sense.
Even so, it’s still interesting to think about other possibilities on how the universe will end. So in honour of World Space Week, I’ve decided to compile just a few (of my favourite) theories that might bring about the end of space, time and everything we know and love. Should be good, no?
So. The two biggest factors for the universe’s growth are gravity and expansion. The Big Bang theory states that once, matter first existed as a singularity in an infinite abyss. It then suddenly expanded and continues on expanding even till today. Gravity is the glue that helps shape everything else; stars, galaxies, and notorious black holes.
With that being said, the most widely known theory – apart from the Big Freeze – is the Big Crunch. Fun fact; the use of the word ‘big’ is somewhat of a bitter-but-hilarious joke in the scientific community mostly because the guy who coined the term ‘Big Bang’ used it derogatorily… but for some reason scientists started to use it and it stuck ever since.
Anyway, about the Big Crunch. So the universe is still expanding, and we’re living in a ‘Goldilocks’ time where the balance between the expansion rate and gravity is in equilibrium. But what if one day, there is a tipping point in which gravity starts to take over? This is conceivable due to the existence of dark matter – these invisible, unknown strings and webs that are magically holding the universe intact. Like a scaffolding to hold a building in place.
More matter = more gravity. More gravity = bigger pulls.
The Big Crunch enters when scientists theorised that maybe the gravitational pull can be too strong and the universe will start to contract. Galaxies will start to collide and planets and stars will merge, eventually resulting the universe to a single huge ball of energy and finally, gravity will take full control and consume itself into a black hole.
Some might argue that at the very last second before the black hole, energy from the contracting matter will bounce back and propel itself into another Big Bang. They call this the ‘Big Bounce’, which is a much more… optimistic version of the Big Crunch. So contemplate on the notion that maybe, if this theory does come into play, our Big Bang might have been somebody else’s Big Crunch.
Unfortunately, both of these theories have proven to be quite impossible because in 1998, scientists discovered that we’re actually expanding at an accelerated rate. Due to this, we can pretty much rule out the theory that we might get crushed by our own sister galaxy when we wake up one morning.
The Black Hole theory is by far my favourite.
Numerous discoveries have been made of black holes existing in the heart of galaxies. Even our own Milky Way houses a supermassive black hole right smack in the middle of it. This theory suggests that because of the black hole’s strong gravitational pull and its nature to ‘eat’ everything that comes close, our galaxies will eventually fall into its event horizon (think: Gargantua; the huge black hole in Interstellar. Imagine our whole galaxy getting swallowed up in that thing).
Aptly and disturbingly termed as the ‘cannibalisation of stars and galaxies’, this theory says that most of the matter present will be devoured by black holes. In some ‘benign’ parts of the universe, we’d be left with nothing but darkness and gravity wells. In other more violent parts, huge black holes will consume smaller ones and become even bigger black holes. After their raging battles, they will ultimately reach a stagnant point and start to die. When the last one dies, all that would be left are particles littering the abyss of what used to be clusters of bright burning rocks, and dust. Sounds neat.
However, this theory’s viability is pretty much long gone. It’s highly unlikely that this will happen mostly because we know that the universe is expanding, as previously mentioned. It all comes back to that. The fact that galaxies are moving further apart has voided the possibility of them being dragged into the black hole’s gravitational border, hence, discredits this theory altogether.
Now, the Big Rip holds a special place in my heart, mostly having to do with its unfortunate term but also because of the underlying terror behind that hilarious name.
After the hypothesis that suggested the theoretical existence of dark energy – which is the only thing that can justify why the universe is expanding at such a fast rate – the scientific community has conceptualised another theory; the Big Rip. How it goes is that if this mysterious dark energy increases, the universe will expand faster and faster until it eventually rips itself apart due to the accelerated pace. First, galaxies will start dispersing, then planets, then us. We’ll literally be ripped apart so fast that in a mere few minutes, every matter in the universe will disintegrate, leaving absolutely nothing, not even the empty vacuum in space. So ultimately, reality will cease to exist.
It’s a pretty violent way for the universe to go and the scariest part is that it’s not that far off from being true, especially because we’re right in the middle of the phenomenon right now. However, we’re looking at another 16 billion years of expansion before this theory can be put to the test. Looking at the bigger picture though, 16 billion years isn’t a lot of time. It’s a little more than the age of our universe right now.
Regardless, these still remain as theories, and whether or not they will happen remains to be seen. Cosmologists in future might be able to solidify these theories with more accurate facts but for now, we’re only left with speculations.
The cosmos is one of the most interesting things one can ever learn about, due to the magnitude of its mystery and how its discoveries have scientifically justified our conception.
In case anyone wants to delve deeper into this, I recommend checking out these links I’ve used for references.
- John Baez on a Brief History of the Universe (Counting down from the Big Bang) and The End of the Universe
- NASA – The Big Freeze
- SDSS on The Expanding Universe
- Staple Wikipedia references on Accelerating Expansion of the Universe and Ultimate Fate of the Universe
- Listverse’s compilation – 10 Theories on How The Universe Will End
- StarDate – Black Holes
- HowStuffWorks Science – The Big Crunch
Also, I very much recommend checking out this mini-series called How The Universe Works. Michio Kaku and Michelle Thaller are honestly my favourite people.