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posted by janrinok on Thursday January 09 2020, @03:25AM   Printer-friendly
from the looking-for-the-wrong-thing dept.

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


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  • (Score: 2) by c0lo on Thursday January 09 2020, @06:28AM (3 children)

    by c0lo (156) Subscriber Badge on Thursday January 09 2020, @06:28AM (#941352) Journal

    but I was taught long ago that why? is not a scientific question

    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.

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    https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
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  • (Score: 3, Interesting) by Coward, Anonymous on Thursday January 09 2020, @03:41PM (2 children)

    by Coward, Anonymous (7017) on Thursday January 09 2020, @03:41PM (#941454) Journal

    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)

      by hendrikboom (1125) Subscriber Badge on Thursday January 09 2020, @08:25PM (#941584) Homepage Journal

      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

        by Coward, Anonymous (7017) on Friday January 10 2020, @01:44PM (#941860) Journal

        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.