American astrophysicist Robert Caldwell has stated in his current work that there are still three scenarios being discussed for the fate of the universe.
First, the universe could continue expanding indefinitely, ultimately leading all matter and phenomena to merge into energy in the form of “the death of heat.” Second, gravity could be the cause of the universe collapsing once again, resulting in a reverse Big Bang, known as the Big Crunch. Third, dark energy could cause the universe to expand at an increasingly faster rate, eventually tearing apart in a state known as the Big Rip.
But before discussing the end of the universe, let’s examine how the universe came into existence. According to our current understanding, time and space began with the Big Bang. At that moment, a tiny, incredibly hot, and dense point exploded.
Afterward, everything cooled down to a reasonable level, and particles began to form larger structures like galaxies, stars, and all life on Earth. The time we live in today is approximately 13 billion years from the universe’s starting point. However, the future of the universe remains uncertain due to various scenarios.
In the first scenario, the universe will fade away as heat dissipates, with all stars burning out and leaving remnants known as white dwarfs and neutron stars. The largest stars will be drawn into black holes. Although these “monsters” (black holes) are not as greedy as people often hear, over time, their tremendous gravitational pull will consume almost everything into their bottomless pits.
“And then something incredibly strange will happen,” says astrophysicist Caldwell.
It is believed that black holes emit Hawking radiation. According to British astrophysicist Kevin Pumbblet, this radiation gradually steals tiny bits from the massive black hole, causing it to slowly evaporate. Eventually, all black holes will evaporate, leaving nothing but empty space.
Conversely, if the Big Crunch scenario occurs, the gravitational pull of stars and galaxies will one day pull the entire universe back together. This process is similar to the reverse of the Big Bang, with objects in the universe colliding and merging, and eventually, stars and planets recombine, and everything in the universe returns to an extremely tiny, dense point.
These are some temporary hypotheses about the future of the universe. Caldwell likens it to “like the tide going up and down, erasing all traces on the sand, or like when you go camping, when you leave, you clean everything up and leave nothing behind.”
The third possibility is the universe ending in a Big Rip. In this scenario, dark energy, a mysterious substance that acts opposite to gravity, will tear everything apart. The universe’s expansion will accelerate until distant galaxies move even farther away, and we no longer see their light.
Because the universe’s expansion rate is increasing, objects closer to us will begin to disappear behind the “dark energy wall,” as Caldwell describes it, “galaxies splitting, solar systems splitting, and your imagination can go wild. Planets, then atoms, and finally, the universe itself will disintegrate.”
Which ending will occur?
Due to our incomplete understanding of the properties of dark energy, researchers cannot determine which scenario will unfold.
There are also other theories about the universe’s evolution. From the perspective of current physical laws, it is possible that Higgs bosons (particles that give other particles mass) could annihilate everything. The Higgs boson was discovered in 2012 and has a mass about 126 times that of a proton.
But theoretically, this mass of the Higgs can change because the universe might not be in its lowest-energy state at the moment. The entire universe could be in an unstable fake vacuum state, in contrast to the true vacuum state. If the mass of Higgs particles somehow becomes lighter, the universe will fall into a true vacuum state at a lower energy level.
If Higgs particles suddenly decay into smaller, less massive particles, everything else in the universe will be affected similarly. Similarly, photons could gain mass, meaning that sunlight from the sun would become like a rain shower. Whether any life forms could survive such a scenario is unknown.
Caldwell says, “I consider this an environmental catastrophe of particle physics. It doesn’t directly cause the universe’s end; it just makes the universe a difficult place to live.”
(Source: Live Science)