Largest-Ever Supernova Catalog Provides Further Evidence Dark Energy Is Weakening (space.com) 17
Scientists using the largest-ever catalog of Type 1a supernovas -- cosmic explosions from white dwarf "vampire stars" -- have uncovered further evidence that dark energy may not be constant. While the findings are still preliminary, they suggest the mysterious force driving the universe's expansion could be weakening, which "would have ramifications for our understanding of how the cosmos will end," reports Space.com. From the report: By comparing Type 1a supernovas at different distances and seeing how their light has been redshifted by the expansion of the universe, the value for the rate of expansion of the universe (the Hubble constant) can be obtained. Then, that can be used to understand the impact of dark energy on the cosmos at different times. This story is fitting because it was the study of 50 Type 1a supernovas that first tipped astronomers off to the existence of dark energy in the first place back in 1998. Since then, astronomers have observed a further 2,000 Type 1a supernovas with different telescopes. This new project corrects any differences between those observations caused by different astronomical instruments, such as how the filters of telescopes drift over time, to curate the largest standardized Type 1a supernova dataset ever. It's named Union3.
Union3 contains 2,087 supernovas from 24 different datasets spanning 7 billion years of cosmic time. It builds upon the 557 supernovas catalogued in an original dataset called Union2. Analysis of Union3 does indeed seem to corroborate the results of DESI -- that dark energy is weakening over time -- but the results aren't yet conclusive. What is impressive about Union3, however, is that it presents two separate routes of investigation that both point toward non-constant dark energy. "I don't think anyone is jumping up and down getting overly excited yet, but that's because we scientists are suppressing any premature elation since we know that this could go away once we get even better data," Saul Perlmutter, study team member and a researcher at Berkeley Lab, said in a statement. "On the other hand, people are certainly sitting up in their chairs now that two separate techniques are showing moderate disagreement with the simple Lambda CDM model."
And when it comes to dark energy in general, Perlmutter says the scientific community will pay attention. After all, he shared the 2011 Nobel Prize in Physics for discovering this strange force. "It's exciting that we're finally starting to reach levels of precision where things become interesting and you can begin to differentiate between the different theories of dark energy," Perlmutter said.
Union3 contains 2,087 supernovas from 24 different datasets spanning 7 billion years of cosmic time. It builds upon the 557 supernovas catalogued in an original dataset called Union2. Analysis of Union3 does indeed seem to corroborate the results of DESI -- that dark energy is weakening over time -- but the results aren't yet conclusive. What is impressive about Union3, however, is that it presents two separate routes of investigation that both point toward non-constant dark energy. "I don't think anyone is jumping up and down getting overly excited yet, but that's because we scientists are suppressing any premature elation since we know that this could go away once we get even better data," Saul Perlmutter, study team member and a researcher at Berkeley Lab, said in a statement. "On the other hand, people are certainly sitting up in their chairs now that two separate techniques are showing moderate disagreement with the simple Lambda CDM model."
And when it comes to dark energy in general, Perlmutter says the scientific community will pay attention. After all, he shared the 2011 Nobel Prize in Physics for discovering this strange force. "It's exciting that we're finally starting to reach levels of precision where things become interesting and you can begin to differentiate between the different theories of dark energy," Perlmutter said.
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No coauthors, barely any referencing. No peer review. No publication. Resurects a disproven theory (ether) without addressing why it was disproven. Never cited.
We have a term for papers like this in the sciences, and your not going to like it.
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The 'ether' you refer to is the "Luminiferous aether" and my 'ether' has nothing to do with it. Ether's definition is that it is present at every point of space. A quantum field satisfies this definition especially the Higgs field which vacuum expectation value is greater than zero. I even wrote that my ether can be considered a quantum field.
And my presentation is an idea and not a theory. It does not have to be peer reviewed and it is posted under "Research proposal". Maybe someone will find it interestin
Perhaps expected? (Score:3)
The expansion of the universe requires acting against gravity which requires energy. Unless that energy is somehow replenished from outside our universe then it will - for want of a better analogy - be converting from kinetic energy to potential energy and eventually I presume, stop.
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It's quite a reversal. Originally they said dark energy was increasing over time and there would be a 'big rip' when even atoms would be torn apart by expanding space.
Now dark energy is not increasing, but decreasing. Gravity might win after all.
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The expansion of the universe requires acting against gravity which requires energy..
The expansion of mass requires energy. The expansion of space does not.
What happens to potential energy when the mass in question gets so far away that it leaves our local light cone for good? That is, it is so far away that the expansion of spacetime means that anything it emits at or below the speed of light will never get here. That's mind-bogglingly far away, but there really are things going over that edge of "our" universe right now.
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" The expansion of space does not."
When its being resisted by gravity it does.
"What happens to potential energy when the mass in question gets so far away that it leaves our local light cone for good"
Irrevelant: A - B - C
A and C might not be in the same light cone but if A and B are in the same cone and B and C are in the same cone then there's still a gravitational link between A and B.
Dark matter doesn't exist Dark energy is weakening (Score:3)
Re: Dark matter doesn't exist Dark energy is weake (Score:3)
The black hole universe theory (Score:2)
Perhaps "Dark Energy" weakening is caused by the radiation spewing from the black hole the universe currently exists inside of? I mean, why not? We seem to have no real idea what the universe actually is, and the black hole universe theory seems as likely as any other. As the radiation continues to spew out, the dark energy continues to weaken, the expansion of the universe eventually slows, then becomes a contraction that lasts however long it takes for the last of the radiation to flee our parent black ho
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The proposition that our universe exists inside a black hole of another universe is intriguing. As is the possibility that Dark Energy is not constant.
Random thought, what if the dark energy is related to matter falling into the black hole of that 'outer' universe...being somehow converted into Dark Energy of our universe.
Idle speculation.
Re: (Score:3)
Re:hack, refute, repeat (Score:5, Informative)
I'm not an astronomer, but I recognize a hack when I see one. Dark matter was a hack. Dark energy was a hack on a hack. Now they're hacking the hack to the hack
I think you completely misunderstood the article and research. The article is not stating the evidence is weakening for dark energy. It is saying that new evidence is finding that dark energy is weakening meaning that it is not as constant as previously thought. It may be variable. The research is adding more evidence that dark energy and matter exists.
About that standard candle (Score:2)
All of this is held up by faith in the standard candle, which has recently been thrown into question. Type 1a supernovae might not be as consistent absolute brightness as previously believed. Without that? Shrug. We lack a yardstick to measure this.
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That does, indeed, seem to be a big question. OTOH, the "tip of the Red Giant" measure seems to agree with the "type 1a supernova" measure. (But I'm not sure how big the error bars are.)
N.B.: I'm no expert in this field. But I think the actual experts admit to a lot more uncertainty than ever shows up in popular articles.