Is Dark Energy Getting Weaker? New Evidence Strengthens the Case. (quantamagazine.org)
- Reference: 0176778227
- News link: https://science.slashdot.org/story/25/03/20/1431243/is-dark-energy-getting-weaker-new-evidence-strengthens-the-case
- Source link: https://www.quantamagazine.org/is-dark-energy-getting-weaker-new-evidence-strengthens-the-case-20250319/
The DESI team analyzed data from approximately 15 million galaxies collected over three years, more than doubling their previous dataset of 6 million galaxies. Combined with supernova observations and cosmic microwave background data, their analysis shows a 4.2-sigma deviation from the standard Lambda-CDM cosmological model, which assumes dark energy remains constant.
"We are much more certain than last year that this is definitely a thing," said Seshadri Nadathur of the University of Portsmouth, a key DESI researcher. These findings align with recent independent results from the Dark Energy Survey (DES), which earlier this month reported a similar 3.2-sigma tension with Lambda-CDM -- a tension that disappears if dark energy is allowed to vary. If confirmed, evolving dark energy could fundamentally alter cosmologists' understanding of the universe's ultimate fate. Instead of expanding indefinitely until all particles become impossibly separated, the universe might follow alternative trajectories.
"It challenges the fate of the universe," explained Mustapha Ishak-Boushaki from the University of Texas at Dallas. "It's game-changing." Moreover, these findings challenge the simplest explanation of dark energy as vacuum energy, which quantum physics suggests should remain constant. Instead, the results indicate unknown physics, possibly involving a new particle, a modification to Einstein's theory of gravity, or even a new fundamental theory. DESI will continue observing through 2026, eventually producing a final map expected to include 50 million galaxies, potentially providing definitive evidence for this cosmic paradigm shift.
[1] https://www.quantamagazine.org/is-dark-energy-getting-weaker-new-evidence-strengthens-the-case-20250319/
[2] https://arxiv.org/pdf/2503.14738
The simple solution: (Score:2)
The most simple solution to the problems faced here, is that we don't understand physics. In the same way Newton didn't understand the nature of gravity.
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> The most simple solution to the problems faced here, is that we don't understand physics. In the same way Newton didn't understand the nature of gravity.
I have this sneaking suspicion that what we don't know about physics outweighs what we know by a substantial enough amount to make us seem like toddlers trying to understand calculus. Especially astrophysics. There's just so much more out there than we can wrap our puny little minds around, and we've likely barely scratched the surface on the experimentation necessary to understand even gravitational dynamics on the scale of galaxies or superclusters. "Dark energy" and "dark matter" today seem to just be pl
Epistemology (Score:2)
We know there are gaps, and we can identify specific gaps too. Such as a discrepancy between observation and the theoretical Hubble constant. That doesn't mean the theories are completely wrong, but there are factors that are missing.
Dark energy and dark matter are observed facts. They are not just placeholders, but the names we've given to a phenomena that comes up repeatedly in observations. It would be like being skeptical that lightning exists before it was discovered to be an electrical phenomenon. Tha
Re: (Score:1)
There is no proof whatsoever that either dark energy or dark matter exist. There are phenomena that are not understood that may be explained by these, but there is no proof for either.
Re: The simple solution: (Score:3)
> "Dark energy" and "dark matter" today seem to just be placeholders for "all that stuff we don't really have an explanation for yet."
Not "seem", that's literally what they are.
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That's not a solution. That's giving up.
They're chasing this because they don't know what dark energy is. Scientists didn't stop trying to understand gravity after Newton's description, and they didn't stop after Einstein produced a better one. And for whomever figures out dark energy (if anyone does), scientists aren't going to stop with that.
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The phrase that most often leads to scientific breakthroughs in our understanding of the universe isn't "Eureka!", but rather, "Huh... that's weird..."
Finding out that our models fail at a spot we didn't expect them to fail helps us to create more comprehensive theories that better explain the things we don't understand.
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"Eureka!" and "That's weird" occur at different points. "That's weird" is where you start looking for a new anwser, "Eureka" is when you find an answer that fits all your data.
(Yeah, it's a nice quote, but it's wrong.)
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Scientists also came up with more incorrect explanations than correct ones.
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You don't know the power of the dark side!
As my humble zero-analysis Dunning-Kruger take... (Score:2)
... it certainly sounds like dark energy and cosmological inflation might be the same phenomenon, representing a single field or mechanism which weakens by many orders of magntiude with respect to time/density.
Anyone here have any less-Dunning-Kruger takes on the topic? :)
Unknown but Interesting (Score:2)
Yes - we literally have no clue. Inflation is really a "best guess" to explain the large-scale structure of the universe give our current best fundamental understanding of gravity. We have no idea how it occurred, why it occurred or even if it did occur. The exact samething is true of Dark Energy: we have no idea what it is and our best attempts to calculate it given what we know result in a value that is ~130 orders of magnitude wrong.
You can develop theoretical models that connect the two - for example
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My take:
They're parts of the same process in the current models. The inflation is what we see signs of (as in measured distances to supernovae, etc.). Dark energy is how the inflation is explained.
The thing that bothers me is the big bang itself. I don't see how inflation can explain getting through a Schwarzschild barrier, the big bang was clearly dense enough to put the universe within that barrier, and I've been assured that we can't be living within a black hole. ISTM that ONE of those has to be wro
"The DESI team" (Score:2)
I'll be sad if there isn't a LUCY team.