Scientists have discovered that the universe is decaying much faster than they thought, and have pinpointed exactly when it will perish.
A team of researchers from Radboud University in the Netherlands determined that all the stars in the universe will go dark in one quinvigintillion years. That’s a one followed by 78 zeros.
But this is a much shorter amount of time than the previous prediction of 10 to the power of 1,100 years, or a one followed by 1,100 zeros.
The process they believe is driving the death of the universe is related to Hawking radiation, where black holes emit radiation as they gradually ‘evaporate’ into nothing.
This was thought to be a phenomenon exclusive to black holes, but the researchers showed that things like neutron stars and white dwarfs can also evaporate similarly to black holes.
Both neutron stars and white dwarfs are the final stage of a star’s life cycle. Massive stars explode into supernovas and then collapse into neutron stars, whereas smaller stars like our sun devolve into white dwarfs.
These ‘dead’ stars can persist for an extremely long time. But according to the researchers, they gradually dissipate and explode once they become too unstable.
In other words, knowing how long it takes for a neutron star or a white dwarf to die helps scientists understand the maximum lifespan of the universe, because these will be the last stars to die out.
Determining how long it takes for a neutron star (pictured) to dissipate ‘sets a general upper limit for the lifetime of matter in the universe,’ according to the researchers
Previous studies did not take Hawking radiation into account, and therefore overestimated the maximum lifespan of the universe, according to lead researcher Heino Falcke, professor of radio astronomy and astroparticle physics at Radboud University.
Falcke and his colleagues sought to correct this by calculating how long it takes for neutron stars and white dwarfs to decay via a Hawking-radiation-like process, finding that it takes one quinvigintillion years.
‘So the ultimate end of the universe comes much sooner than expected, but fortunately it still takes a very long time,’ he said in a statement.
In 1975, renowned physicist Stephen Hawking proposed that particles and radiation could escape from a black hole, which contradicted the widely-held belief that nothing escapes the gravitational pull of these extremely massive objects.
But according to Hawking, two temporary particles can form at the edge of a black hole. Before they can merge, one particle is sucked back into the black hole and the other escapes.
These escaped particles are Hawking radiation.
As more and more of these particles escape over time, the black hole gradually decays. This also contradicts Albert Einstein’s theory of relativity, which states that black holes can only grow.
The team used their 2023 study, published in the journal Physical Review Letters, to lay the groundwork for the recent discovery.
In the previous work, Falcke and his colleagues showed that all objects with a gravitational field should be able to evaporate via a similar process.
In 1975, renowned physicist Stephen Hawking proposed that particles and radiation could escape from a black hole, which contradicted the widely-held belief that nothing escapes these extremely massive astronomical objects
What’s more, their calculations suggested that the evaporation rate depends only on the object’s density.
From there, applying the concept of Hawking radiation to neutron stars and white dwarfs for their new study was relatively straightforward.
Those findings have been accepted for publication by the Journal of Cosmology and Astroparticle Physics, but are currently housed on the pre-print server arXiv.
Even though these new calculations cut an inconceivable number of years off the universe’s lifespan, it doesn’t change the fact that humans don’t have to worry about the end of everything anytime soon.
But they do offer a new look at Hawking’s controversial theory.
‘By asking these kinds of questions and looking at extreme cases, we want to better understand the theory, and perhaps one day, we will unravel the mystery of Hawking radiation,’ said co-author Walter van Suijlekom, professor of mathematics at Radboud University.