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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: 5, Interesting) by DrkShadow on Thursday January 09 2020, @04:15AM (7 children)
I finally found it.
Years ago, I read an article saying that the study leading to the ground-breaking announcement that the expansion of the universe was accelerating was based on a sample size of.. wait for it.. 75 supernovae. Based on a sample of 75 events, they concluded that the universe was expanding at an ever-increasing rate, drew up the dark matter/dark energy debate, and oh the money that has been spent on this weakly-backed theory.
A couple years ago a new study came out that used modern science and a greater sample size (740 events) and doesn't come to the conclusion that the universe is definitely expanding at an increasing rate.
https://www.sciencealert.com/no-the-universe-is-not-expanding-at-an-accelerated-rate-say-physicists [sciencealert.com]
Another nail in the coffin of Dark science. We know everything! ;-)
(Score: 1, Insightful) by Coward, Anonymous on Thursday January 09 2020, @05:00AM (2 children)
There are broader implications to the debate, because key proponents of the consensus dark-energy theory (which relies heavily on curve fits) went on to found Berkeley Earth [berkeleyearth.org], where they have been touting curve fits based on CO2 and global temperature.
(Score: 3, Informative) by Coward, Anonymous on Thursday January 09 2020, @06:25PM (1 child)
Down-mod me all you want, but it is known from machine learning that large neural networks learning from small data sets often overfit [wikipedia.org]. Scientists are also neural networks, and these data sets are small.
(Score: 2) by Coward, Anonymous on Thursday January 09 2020, @06:35PM
And bigger neural networks (many people in the consensus) perform even worse than small ones when there is too little data.
(Score: 4, Interesting) by FatPhil on Thursday January 09 2020, @09:48AM (1 child)
Sarkar's result was 3-sigma in favour of accelerating expansion.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Thursday January 09 2020, @12:46PM
And the non-accelerating scenario wasn't consistent with other observations, like the universe having matter in it.
(Score: 2) by DannyB on Thursday January 09 2020, @03:37PM (1 child)
So is The Big Crunch back in style once again?
To transfer files: right-click on file, pick Copy. Unplug mouse, plug mouse into other computer. Right-click, paste.
(Score: 0) by Anonymous Coward on Thursday January 09 2020, @04:45PM
It is. Recently in Nature Astronomy: https://www.nature.com/articles/s41550-019-0906-9 [nature.com]
Same w/o paywall: https://arxiv.org/abs/1911.02087 [arxiv.org]