Stars will continue to explode long after the universe is cold and “dead”. A scientist is determined to dive through the rabbit hole to find the last supernova that will ever happen.
When the universe as we know it “dies,” it will be “a sad, lonely, cold place,” according to theoretical physicist Matt Caplan, assistant professor of physics at Illinois State University. said in a statement. In a new study, Caplan calculated how dead stars might change over time and determined when the last supernova in the universe’s distant future will explode.
The end of the universe is “known as a” heat death, “where the universe consists mainly of black holes and burned-out stars,” Caplan said in the statement. “I became a physicist for a reason. I wanted to think about the big questions – why is the universe here and how is it going to end?”
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In the new study, Caplan looked at the future of stellar explosions. Massive stars explode in supernovae when iron accumulates in their core and accumulates and triggers the collapse of the star. But smaller stars like white dwarfs – ultra-dense stellar bodies that are formed when sun-like stars use up all of their nuclear fuel – don’t have the gravity and density to produce that iron. However, Caplan found that white dwarfs become denser over time and could become “black dwarf stars” that can actually produce iron.
“As white dwarfs cool off over the next trillion years, they will darken, eventually freeze solid, and become ‘black dwarf stars’ that no longer shine,” said Caplan. “Stars glow because of nuclear fusion – they’re hot enough to knock small nuclei together and form larger nuclei, releasing energy. White dwarfs are ashes, they are burned out, but fusion reactions can still occur due to quantum tunneling, only much more slowly. ”
Quantum tunneling is a phenomenon in which a subatomic particle “tunnels” through a barrier that appears impossible to penetrate when it disappears, and reappears on the other side of the barrier.
Caplan noted that this fusion is key to creating iron in black dwarfs and triggering this type of supernova.
The new study shows how many iron black dwarfs of different sizes would have to produce to explode. Caplan calculated that the first of these “black dwarf supernovae” will explode in about 10 to 1,1000 years – an almost unimaginably large number. “In years, it’s like saying the word ‘trillions’ nearly a hundred times. If you spelled it out, it would take up most of a page. It’s amazingly far in the future,” he said.
He found that the most massive black dwarfs will explode first, followed by less and less massive stars until there are none left, which he expects in about 10 ^ 3.2000 years. “It’s hard to imagine anything coming after that,” he said. “The black dwarf supernova could be the last interesting event in the universe. You might be the last supernova ever.”
What will the “sad, lonely” universe look like at this point after the last supernova has exploded? According to Caplan, “galaxies will have dispersed, black holes will have evaporated, and the expansion of the universe will have pulled all remaining objects apart so far that no one will ever see any of the others explode. It won’t even be physically possible.” so that the light travels so far. “
This study was released on August 7th in the Royal Astronomical Society’s Monthly Notices.
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