Universe will end sooner than expected

Scientists calculate and say the universe's expiration date is 'much sooner than expected' 

New calculations suggest that the universe's most enduring celestial objects, such as white dwarf stars, are decaying faster than previously thought. As the story of our cosmos moves forward, stars will slowly burn out, planets will freeze over, and black holes will devour light itself. Eventually, on timescales so long humanity will never witness them, the universe will fade into darkness. The universe may be coming to an end a few years sooner than expected, like trillions sooner. That's the finding of some scientists in the Netherlands. The expiration date for the universe is now sooner than experts previously thought, new research suggests. 

But if you've ever wondered exactly when it all might end, you may find it oddly comforting, or perhaps a bit unsettling, to know that someone has actually done the math. As it turns out, this cosmic finale might arrive sooner than scientists previously thought. Experts had previously put the lifespan of the universe at 10 to the power of 1,100 years (the number would be 1 followed by 1,100 zeroes). But researchers at Radboud University in Nijmegen, the Netherlands, have new calculations suggesting the universe is decaying much faster than previously thought. Their findings, put the universe's end at 10 to the power of 78 years (a 1 with 78 zeros), that's more than a vigintillion years (1 followed by 68 zeroes) but less than a Googol years (1 with 100 zeroes). In cosmic terms, this estimate is a dramatic advancement from the previous prediction of 10 to the power of 1,100 years, made by Falcke and his team in 2023. "The ultimate end of the universe comes much sooner than expected, but fortunately it still takes a very long time," Heino Falcke, a theoretical astrophysicist at the Radboud University in the Netherlands, who led the new study, said. 

He and fellow researchers at the university, quantum physicist Michael Wondrak and mathematician Walter van Suijlekom, based their calculations on a reinterpretation of a theorem derived by the late physicist Stephen Hawking. Within the theory of "Hawking radiation," particles and radiation could escape from a black hole, which would eventually lead to the black hole's decay. That's in opposition to Albert Einstein's theory of general relativity, which held that black holes could only grow. The team's new calculations focus on predicting when the universe's most enduring celestial objects, the glowing remnants of dead stars such as white dwarfs and neutron stars, will ultimately fade away. This gradual decay is driven by Hawking radiation, a concept proposed by physicist Stephen Hawking in the 1970s. The theory suggests a peculiar process occurs near the event horizon, the point of no return, around black holes. Normally, virtual pairs of particles are constantly created by what are known as quantum fluctuations. These particle pairs pop in and out of existence, rapidly annihilating each other. Near a black hole's event horizon, however, the intense gravitational field prevents such annihilation. Instead, the pair is separated: one particle, one carrying negative energy, falls into the black hole, reducing its mass, while the other escapes into space.

Taking Hawking radiation into account, the researchers said they based their universal end date on how long it would take for the decay of a white dwarf star, considered the most persistent of celestial bodies. "This sets a general upper limit for the lifetime of matter in the universe," they wrote in article. Here on Earth, we will be unlikely to match that upper timeline as Hawking himself theorized that the Earth's population will consume enough energy to engulf the planet in a "ball of fire" within 600 years. If that doesn't come to pass, our sun will cook the Earth within a billion years anyway. Over incredibly long timescales, Hawking's theory suggests this process causes the black hole to slowly evaporate, eventually vanishing. Falcke and his team extended this idea beyond black holes to other compact objects with strong gravitational fields. They found that the "evaporation time" of other objects emitting Hawking radiation depends solely on their densities. This is because unlike black hole evaporation, which is driven by the presence of an event horizon, this more general form of decay is driven by the curvature of space-time itself.

For the rest of the universe, recent research suggests the dark energy that's led to the expansion of the universe could be decelerating, a possible sign the universe could begin to decay or collapse on itself in what some scientists have called the "big crunch." The team's new findings,  offer a new estimate for how long it takes white dwarf stars to dissolve into nothingness. Surprisingly, the team found that neutron stars and stellar-mass black holes decay over the same timescale: about 10 to the power of 67 years. This was unexpected, as black holes have stronger gravitational fields and were thought to evaporate faster. "Now, there is the possibility that everything comes to an end," said University of Texas at Dallas cosmologist Mustapha Ishak-Boushaki, a collaborator on the dark energy research, said. "Would we consider that a good or bad thing? I don't know." If even white dwarf stars and black holes eventually dissolve into nothing, what does that say about us? Perhaps it suggests meaning isn't found in permanence, but in the fleeting brilliance of asking questions like these, while the stars are still shining. "But black holes have no surface," Michael Wondrak, a postdoctoral researcher of astrophysics at Radboud University and a co-author of the study, said. "They reabsorb some of their own radiation, which inhibits the process."