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New evidence shows that the key assumption made in the discovery of dark energy is in error:
The most direct and strongest evidence for the accelerating universe with dark energy is provided by the distance measurements using type Ia supernovae (SN Ia) for the galaxies at high redshift. This result is based on the assumption that the corrected luminosity of SN Ia through the empirical standardization would not evolve with redshift.
New observations and analysis made by a team of astronomers at Yonsei University (Seoul, South Korea), together with their collaborators at Lyon University and KASI, show, however, that this key assumption is most likely in error. The team has performed very high-quality (signal-to-noise ratio ~175) spectroscopic observations to cover most of the reported nearby early-type host galaxies of SN Ia, from which they obtained the most direct and reliable measurements of population ages for these host galaxies. They find a significant correlation between SN luminosity and stellar population age at a 99.5 percent confidence level. As such, this is the most direct and stringent test ever made for the luminosity evolution of SN Ia. Since SN progenitors in host galaxies are getting younger with redshift (look-back time), this result inevitably indicates a serious systematic bias with redshift in SN cosmology. Taken at face values, the luminosity evolution of SN is significant enough to question the very existence of dark energy. When the luminosity evolution of SN is properly taken into account, the team found that the evidence for the existence of dark energy simply goes away (see Figure 1).
Commenting on the result, Prof. Young-Wook Lee (Yonsei Univ., Seoul), who led the project said, "Quoting Carl Sagan, extraordinary claims require extraordinary evidence, but I am not sure we have such extraordinary evidence for dark energy. Our result illustrates that dark energy from SN cosmology, which led to the 2011 Nobel Prize in Physics, might be an artifact of a fragile and false assumption."
More information:
Early-Type Host Galaxies of Type Ia Supernovae. II. Evidence for Luminosity Evolution in Supernova Cosmology, Astrophysical Journalarxiv.org/abs/1912.04903
Journal information: Astrophysical Journal
(Score: 4, Funny) by Coward, Anonymous on Thursday January 09 2020, @03:29AM (24 children)
Dark energy is the result of making universe-shaking adjustments to phyics because of a minor discrepancy in the data. What happened to Occam's razor?
OTOH, the ApJ paper hasn't even been published (just the preprint) and will be challenged. Other papers have been critical of dark energy (AKA cosmic expansion), and so far nothing has stuck. The phys.org summary just quotes the press release from Yonsei University, where most of the authors are based. Other astrophysicists will also have something to say.
A co-author (Suntzeff) of the Schmidt et al. 1998 discovery paper for dark energy is active on Twitter [twitter.com].
(Score: 5, Funny) by takyon on Thursday January 09 2020, @03:50AM (3 children)
The existence of Gaaark energy cannot be conclusively disproven.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Gaaark on Thursday January 09 2020, @11:07AM (1 child)
Hey!,
my farts are real. Unlike some things.....
;)
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 0) by Anonymous Coward on Thursday January 09 2020, @04:30PM
my farts are integers
(Score: 1) by RandomFactor on Thursday January 09 2020, @04:11PM
It is almost like they took and applied a random factor to the universe.
В «Правде» нет известий, в «Известиях» нет правды
(Score: 3, Interesting) by HiThere on Thursday January 09 2020, @04:16AM (8 children)
All correct, but the evidence isn't, to my non-expert mind, unreasonable. There have been prior indications that the "Supernova type 1a standard candle" isn't all that reliable. (The last time, IIRC, the claim was that they fell into two major categories, only one of which was a suitable standard candle, and there wasn't an obvious way to separate them.)
That said, explaining a flat space-time seems, to me, to be a major problem.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 1, Funny) by Anonymous Coward on Thursday January 09 2020, @04:33AM
How so? Time is made from holes in space. When they combine with electrons time ceases to exist.
(Score: 2) by Coward, Anonymous on Thursday January 09 2020, @04:47AM (6 children)
I'm not a cosmologist, but I was taught long ago that why? is not a scientific question. Dark energy and dark matter bother me, but not that space-time is flat. The origin of the universe will always be a mystery. It's fine to keep digging deeper, but eventually the quest will run out of steam without reaching an end point.
(Score: 2) by c0lo on Thursday January 09 2020, @06:28AM (3 children)
How come? Care to elaborate?
My point: without why?, there's no motivation search for "making everything as simple as possible" - i.e. search for even simpler principles that can explain everything that you know so far. Further, without daring to ask why?, one risks the ignorance of evidence that the theories of the day cannot explain - on the ground that if there's no theoretical explanation then it should be impossible/improbable/a measurement error/a statistical fluctuation and we can/must ignore it.
Granted, at a certain point, one needs to accept the "but not simpler" lower boundary, but I think that's a boundary to be challenged all the time and why? is too good a tool to do without.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 3, Interesting) by Coward, Anonymous on Thursday January 09 2020, @03:41PM (2 children)
It always seemed more reasonable that scientists should try to describe what is happening instead of why. Theories are created to describe this knowledge of what, and together with the resulting equations form an algorithmic compression of knowledge. A tighter theory is favored because it gives more compression. That's the reason to want simplification. Sometimes the data deviate from the old theory and a new, more accurate, theory is needed.
Why? is more a religious question that science doesn't have to answer. Why? can also be dismissed as a human construct, while what is more neutral.
(Score: 3, Touché) by hendrikboom on Thursday January 09 2020, @08:25PM (1 child)
Why did the rock fall to the ground?
Because it was following a geodesic in space-time that was curved by the earth's mass.
Sounds like an answer to a why question to me.
Why in English can be answered by a cause or a purpose.
-- hendrik
(Score: 2) by Coward, Anonymous on Friday January 10 2020, @01:44PM
What happens after you drop the rock?
You get all of the same answers from "what" without the baggage of being stuck in a recursive loop.
(Score: 1, Funny) by Anonymous Coward on Thursday January 09 2020, @07:05AM
There will be no "why" when he sees your "smokey eye" shadow! There will only be "why not?"
(Score: 3, Touché) by Mojibake Tengu on Thursday January 09 2020, @09:26AM
Why you were taught that?
Respect Authorities. Know your social status. Woke responsibly.
(Score: 4, Insightful) by PiMuNu on Thursday January 09 2020, @09:54AM (10 children)
> universe-shaking adjustments to phyics
No! Maybe universe-shaking adjustments to your preconceived notions of what physics should be.
Your preconceived notions require that cosmological constant is 0, but this is not required by any physical principle. So we should let it float, and then see what value best fits *the data*.
It is "easier" if the earth is at the centre of the universe.
It is "easier" if Galilean relativity is correct.
It is "easier" if there is no dark energy.
But we should always modify the theory to fit observation, not the other way around.
(Score: 0) by Anonymous Coward on Thursday January 09 2020, @01:55PM
True, but the constant was only invented to save the static universe hypothesis. A hypothesis that Hubble showed was incorrect, when he showed that the universe was expanding (as the constant-less equations showed was likely).
Only later did they resurrect this constant when the data seemed to show that the universal expansion was accelerating.
(Score: 4, Informative) by Coward, Anonymous on Thursday January 09 2020, @03:19PM (6 children)
In your other examples, there was no way to square the observations with the theory, or make the theory hang together consistently. That's why the old theories failed and were replaced. For dark energy, the "observations" are not observations at all, but belief that magic sauce "standardization" can turn supernovae into standard candles of known brightness. Rather than admitting that these standardization adjustments are a weak basis for the follow-on theory of dark energy, cosmologists have gone all-in.
This wouldn't be the first time that systematic errors were underestimated [stackexchange.com] and for sociological reasons, physicists held on to a wrong conclusion for decades.
(Score: 2) by DannyB on Thursday January 09 2020, @03:35PM
Bring back the Aether [wikipedia.org] (aka, Luminiferous aether [wikipedia.org])
The lower I set my standards the more accomplishments I have.
(Score: 2) by PiMuNu on Thursday January 09 2020, @08:26PM (4 children)
I am all for dropping dark energy if the data turns out not to support it because of a wrong systematic error (or any other reason).
I just object to the grandparent preferring this theory or that theory on the grounds of prettiness or some other subjective thing.
(Score: 2) by Coward, Anonymous on Sunday January 12 2020, @07:54AM (3 children)
Physics is about describing the world with the fewest possible terms. So yes, that does imply a preference for an explanation of supernova magnitudes that does not rely on the cosmological constant. Einstein didn't like [scitation.org] the constant either.
(Score: 2) by PiMuNu on Monday January 13 2020, @10:07AM (2 children)
> Physics is about describing the world with the fewest possible terms.
That's a pretty big statement.
1. We have been lucky so far that the reductionist approach works. But there is no reason that it should.
2. We know General Relativity is incomplete. E.g. vacuum energy can come into play which is not well understood. A later iteration of standard model may constrain cosmological constant to non-zero value.
So in general if the data doesn't support 0 cosmological constant then we have to follow the data.
There is a slight subtlety, which maybe you don't know? General Relativity is built on a couple of axioms:
1. speed of light is true for gravity
2. gravitation mass is the same as inertial mass - i.e. force from a planet is bigger because it has more "gravitation mass" and force required to push a truck is big because it has more "inertial mass"
There axioms constrain lots of things, but don't constrain the cosmological constant.
> Einstein didn't like the constant either.
I know, but it doesn't mean it is wrong. Falling back on [famous physicist] is a lazy argument. I think there should be a physics equivalent of Godwin Rule!
(Score: 3, Insightful) by Coward, Anonymous on Monday January 13 2020, @02:50PM (1 child)
Every new term in physics is worth a Nobel Prize. If only to protect physics from human selfishness, skepticism against new claims is required.
(Score: 2) by PiMuNu on Monday January 13 2020, @03:19PM
> skepticism against new claims is required.
Can't argue with that; and given the nature of TFA, justified!
(Score: 1) by unhandyandy on Friday January 10 2020, @03:47AM (1 child)
"Your preconceived notions require that cosmological constant is 0"
No, my preconceived notion is that we haven't overlooked 68% of the universe over the 10000 years of recorded history. That notion may be wrong, but it requires more evidence to set it aside than has been produced.
(Score: 2) by PiMuNu on Friday January 10 2020, @10:50AM
> over the 10000 years of recorded history.
That is an insane point of view, are you a troll?
We overlooked physics for about 9600 years of recorded history.
We overlooked any theoretical understanding of gravitation for about 9700 years of recorded history.
We overlooked any theoretical understanding of electromagnetism for about 9800 years of recorded history.
We overlooked cosmology/general relativity for about 9900 years of recorded history.
Do you deny physics? Perhaps you just deny general relativity?