Scientists are homing in on the nature of a mysterious force called dark energy, and nothing short of the fate of the universe hangs in the balance.
The force is enormous – it makes up nearly 70 per cent of the universe. And it is powerful – it is pushing all the stars and galaxies away from each other at an ever-faster rate.
And now, scientists are getting a little closer to understanding how it behaves. The big question is whether this dark energy is a constant force, which scientists have long thought, or whether the force is weakening, a surprising wrinkle tentatively proposed last year.
Results presented at a meeting of the American Physical Society bolster the case that the force is weakening, although scientists are not yet certain and still haven’t worked out what this means for the rest of their understanding of the universe.
The updated findings come from an international research collaboration that is creating a three-dimensional map to see how galaxies have spread and clustered over 11 billion years of the universe’s history. Carefully tracking how galaxies move helps scientists learn about the forces that are moving them around.
[…] Their updated results, taken with other measurements – exploding stars, leftover light from the young universe, and distortions in galaxy shape – support the idea presented last year that dark energy may be waning.
“It’s moving from a really surprising finding to almost a moment where we have to throw out how we’ve thought about cosmology and start over,” said Bhuvnesh Jain, a cosmologist with the University of Pennsylvania who was not involved with the research.
So kind of like finding out that the speed of light isn’t a constant. No biggie.
It’s not time to completely rule out the idea that dark energy is constant because the new results are still shy of the gold standard level of statistical proof physics requires. The collaboration aims to map around 50 million galaxies and quasars by the end of its survey in 2026.
[…] If dark energy is constant, scientists say our universe may continue to expand forever, growing ever colder, lonelier, and still.
If dark energy ebbs with time, which now seems plausible, the universe could one day stop expanding and then eventually collapse on itself in what’s called the Big Crunch.
So, the universe might expand forever, or it might collapse. Either way, we still don’t know.
If it keeps expanding, meh, boring.
But if it collapses doesn’t that mean there will be another Big Bang? And if so how do we know that “our” Big Bang wasn’t the first one? Maybe our “Big Bang” is the one hundred millionth time a Big Bang has happened.
Of course this depends on a Big Crunch always resulting in a Big Bang, which may not be the case. What if the Big Bang was a one in a billion event? What if instead the Big Crunch results in a singularity that ruptures space time and creates a whole new dimension?
Damn, I should have been a sci-fi writer.
Source: https://www.1news.co.nz/2025/03/20/how-will-the-universe-end-dark-energy-may-hold-the-answer/
