All good things eventually come to an end and our universe is of no exception. There are plenty of ideas as to how the universe began, but how will it end?
We all know that the universe is mainly made of atoms but it isn’t true. Only 4 percent of the universe is made up of atoms and the rest is made up of dark matter and dark energy and unfortunately, we are clueless about what dark energy and dark matter is.
We know the universe won’t last forever because we can look back in time and see how it’s changed. The universe is expanding at an accelerating rate due to this Dark energy which is a mysterious form of energy or force. It is some sort of substance or field that exerts a sort of reverse gravity. It pushes while gravity pulls.
But the universe can’t go on expanding forever. Something’s gotta give, and when it does, it’ll likely happen in one of these ways.
This theory says that the dark energy would become so powerful eventually so as the expansion will continue indefinitely until the galaxies, stars, planets, and matter (even the subatomic particles that comprise all matter) can no longer hold themselves together. At which point, they rip apart.
Theoretical astrophysicist Katie Mack in a talk at the NECSS conference said,
“If the Big Rip is coming, it’s not coming for a very long time. We have at least 120 billion years before we have to worry about this. So you can rest easy — it’ll be a while.”
Another popular theory for the end of the universe is the Big Freeze also referred to as Heat Death or the Big Chill.
In this theory, the universe continues to expand at an ever-increasing speed. As this happens, the heat is dispersed throughout space while galaxies, stars, and planets keep moving farther and farther away from everything else. In the very distant future, intelligent civilizations will look into the sky and think they are alone. Everything will be so far away that the light from distant stars and galaxies can never reach them. New stars will stop forming and eventually, the atomic particles that makeup everything will decay into subatomic particles, and those subatomic particles will move so far away from each other that they can no longer interact.
The universe will be dark, cold, and motionless, which is why this scenario is called “The Big Freeze.” In fact, the “heat” part is solely in reference to the fact that it’s the result of entropy, not the temperature that would result. This is the most likely fate for our universe.
In this model, the expansion of the universe doesn’t continue forever.
If instead of expanding forever, matter in the Universe reaches a point where it starts to decrease over time, it could cause gravity to become the dominant force. This would ultimately cause the Universe to shrink and cause stars, planets and entire galaxies to collide into each other and the Universe would, for all intents and purposes, collapse in on itself.
Some scientists have theorized that the universe we see is the result of a cyclic repetition of the Big Bang, where the first cosmological event came about after the collapse of a previous universe. If the expansion of the Universe slows down and the Big Bang happens in reverse, everything will implode back into a black hole like-singularity.
While the last three scenarios wouldn’t occur for billions of years, Big Slurp could happen at any moment in our universe.
Quantum physics dictates that even in a totally empty vacuum, there is a small amount of energy. But there might also be some other kind of vacuum, which holds less energy.
If this were the case, our universe might experience a catastrophic event when a “bubble” from another alternate universe appears in ours. If this bubble exists in a lower-energy state than our bubble, the universe could be completely destroyed. This sort of a vacuum event could happen at virtually any moment, anywhere in our universe. The bubble could pop over and start expanding at light-speed until it swallowed us entirely. Horrific!
So, which of these possibilities above may result in our reality in the universe would cease to exist?