There are several scenarios of the Universe’s death, but do not panic – it will happen in tens of billions of years.
“A few months before the end, after we have lost the outer planets in a bottomless and growing darkness, the Earth moves away from the Sun and the Moon – from the Earth. We, too, have gone into darkness, alone,” says theoretical cosmologist Kathy Mack of the University of North Carolina in his new book, The End of Everything.
Apocalyptic predictions have always existed in human culture, whether it’s Ragnarick or Doomsday. But in recent decades, scientists have been able to figure out what the death of the universe itself will be.
Thermal death: when time no longer matters.
The universe is likely to die in a state of total disarray when, according to cosmologists, time no longer matters and anything becomes possible.
According to this scenario, space will continue to expand until galaxies collapse, stars burn, and even atoms collapse. At this point, the universe will reach a state of maximum entropy (disorder), which also mixes past and future. “Time will lose its focus,” Mac explains.
Big gap: When gravity breaks down and the Earth explodes.
The expansion of the universe may also lead to a less likely, but much more violent, end: a Big Break.
In this scenario, objects in the universe do not scatter and disintegrate to a peak point in entropy. Instead, the fabric of space-time itself is torn, like a heavily stretched sheet. Gravity gets out of control, says Mac: “Our night sky begins to darken as the Milky Way that crosses the sky gradually disappears: the galaxy evaporates”. The orbits of the planets will begin to change as they move away from the stars, and objects without the power of gravity will begin to fall apart.
If we have a Big Break, it could happen much earlier than Thermal Death. But still, by then, there will be no more Sun or Earth.
Vacuum decay: a sudden end.
Thermal death will kill the universe slowly and gently, the Big Break is spectacular as if in a movie. But if you like quick disconnections, you’ll love the Vacuum Decomposition scenario. Death will be so fast that no one will even notice it.
The universe can be a “real vacuum” – objects in it can always get the lowest energy state. However, there is a “metastable” Higgs field, which means that the universe can be a false vacuum.
Theoretically, this means that if a Higgs particle had “sensed” a real vacuum, it would immediately go into it. It would provoke a spontaneous destruction of the universe, a “quantum death bubble”, as Mac called it.
The death bubble would simply expand at the speed of light, destroying everything in its path.
In principle, the Vacuum Decay can happen at any moment, but cosmologists believe that this will not happen a few tens of billions of years, as we still see distant stars, whose light is not yet darkened because of the probable bubble of quantum death.