About a hundred years ago, the great American astronomer Edwin Hubble discovered that the Universe is going through a constant expansion. At first, astronomers thought the expansion itself was everlasting, and they failed to identify a clear cause behind the acceleration of the expansion itself. They don’t know what’s causing that expansion to accelerate even today, but they have a name for it: dark energy.
Dark energy is the driving force behind the acceleration of the expansion of the Universe, but nobody knows exactly what it is. Instead, astronomers know that it’s much more prevalent than usual matter.
The Universe could reverse its expansion in 100 million years
In case you have any plans for the next 100 million years, we have some bad news for you. After such a huge amount of time, the Universe could start to reverse its expansion, according to a new study published in Proceedings of the National Academy of Sciences.
The Universe has a lot of practice when it comes to constantly expand itself since it’s been doing it since the Big Bang event that occurred 13.7 billion years ago. It seems that it will finally need a break and go the other way around, as the new theory says that our Cosmos will first stop expanding rather than reversing the expansion itself directly.
Scientists even theorize now that dark energy, which we said earlier that it’s driving the acceleration of the Universe’s expansion, could be able to decay over time instead of being a constant force of nature. Without the influence of dark energy, it’s obvious that the expansion would naturally slow down and even go backward at some point.
Gary Hinshaw, who’s a professor of physics and astronomy from the University of British Columbia, explained as LiveScience.com quotes:
To their surprise, dark energy in their model can decay with time,
Its strength can weaken. And if it does so in a certain way, then eventually the antigravitational property of dark energy goes away and it transitions back into something that’s more like ordinary matter.
As you’ve already guessed, there’s a chance that the reverse of the expansion could even lead to the Universe’s death. But there’s also a chance for rebirth. However, there’s no need to worry unless you’re planning to be around in the next few billions of years from now.