New analysis suggests dark energy might not be necessary

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The uncertainty of science: A new peer-reviewed paper in a major astronomy science journal suggests that dark energy might not actually exist, and that the evidence for it might simply be because the original data was biased by the Milky Way’s own movement.

What [the scientists in this new paper] found is that the best fit to the data is that the redshift of supernovae is not the same in all directions, but that it depends on the direction. This direction is aligned with the direction in which we move through the cosmic microwave background. And – most importantly – you do not need further redshift to explain the observations.

If what they say is correct, then it is unnecessary to postulate dark energy which means that the expansion of the universe might not speed up after all.

Why didn’t Perlmutter and Riess [the discoverers of dark energy] come to this conclusion? They could not, because the supernovae that they looked were skewed in direction. The ones with low redshift were in the direction of the CMB dipole; and high redshift ones away from it. With a skewed sample like this, you can’t tell if the effect you see is the same in all directions.

The link is to a blog post by a physicist in the field, commenting on the new paper. Below the fold I have embedded a video from that same physicist that does a nice job of illustrating what she wrote.

This paper does not disprove dark energy. It instead illustrates the large uncertainties involved, as well as show solid evidence that the present consensus favoring the existence of dark energy should be questioned.

But then, that’s how real science works. When the data is sketchy or thin, with many assumptions, it is essential that everyone, especially the scientists in the field, question the results. We shall see now if the physics community will do this.

Hat tip to reader Mike Nelson.


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  • wayne

    holy cow, there’s an entire Industry devoted to “dark energy.” (these people, will not go quietly….)
    ‘Dark Energy’ = “Luminiferous aether.”

  • I’ve always been surprised by the zealotry and the absolute certainty that scientists have pushed this the idea of dark energy. It reminds me of climate science. I saw a professor give a talk a while back and he touched on the topic, and he was a little emotional and defensive about the topic without being prompted. Given the nature of the data (it’s indirect measurements and noise, etc…), I’ve always thought that some of the dark matter conclusions should have been treated with a little more caution. I’m very curious as to how this will work itself out.

  • wayne

    Dark Energy (Lecture 1)
    Dr. Varun Sahni
    [part of “Cosmology – The Next Decade” Program presentation]
    International Center for Theoretical Sciences, January 2019

    “Is dark energy really just a cosmological constant (Lambda), or is it something dynamical, perhaps even a clue that Einstein’s general relativity needs modifications at cosmological scales? Is dark matter a new particle beyond the Standard Model, and do its microscopic properties leave any imprint at cosmological or galactic scales (e.g., deep inside galaxy clusters, or in dwarf galaxies)? The nature of dark matter would also have very interesting consequences for the reionization history of the Universe, which is already being constrained by observations of high redshift quasars and galaxies and is expected to be determined in considerable detail by upcoming and future 21cm experiments.”

  • Lee S

    I have plenty to chew on here…. Thanks for keeping me stimulated while I am trying to recover from the flu!
    I haven’t started digging into the links yet, but I have always thought that dark energy and dark matter ( both of which originated as “place holders” ) are pretty dodgy concepts and it’s much more likely that we are missing something much more fundamental in cosmology….

  • Edward

    From Robert’s quote from the link: “Why didn’t Perlmutter and Riess [the discoverers of dark energy] come to this conclusion?

    Did Perlmutter and Riess discover dark energy or did they conclude that it is there in order to explain the observations? Wouldn’t the phrase “the inventors of dark energy” be more appropriate, since dark energy has yet to be observed directly?

  • Edward: It is important to know that Perlmutter and Riess were part of two completely independent research teams. They both came to the same conclusions, independently. Moreover, as astronomer Mario Livio once told me, the result was exactly the opposite of what they expected, so they both worked very hard to challenge it.

    I do not suspect malfeasance here. It instead falls under the uncertainty of science, which is especially uncertain on the edges of cosmology, where the hard facts are so tenuous.

  • wayne

    “Fashion, Faith and Fantasy in Physics”
    Dr. Roger Penrose
    The Royal Institution March 2017

    “Can the following of fashion, blind faith, or flights of fantasy have anything seriously to do with the scientific quest to understand the universe? Surely not – but Roger Penrose argues that researchers working at the extreme frontiers of physics are as susceptible to these forces as anyone else, and that fashion, faith, and fantasy, while sometimes highly productive in physics, may be leading today’s researchers astray in three of that field’s most important areas—string theory, quantum mechanics, and cosmology.”

  • wayne

    here we go…
    psychedelic country music:
    (who would have thought?!)

    Sturgill Simpson
    “Turtles All The Way Down”
    (The official VEVO music-video)
    April 2014

  • wayne

    hope you feel better!


    “The Trouble with Physics”
    Lee Smolin *2006*
    Microsoft Research

  • Phil Berardelli

    I covered the discovery of dark energy at the time, and I interviewed Riess and found him to be scrupulous and sincere, and by no means dogmatic. He and the other researchers derived the discovery from the data about the Type 1A redshifts. The supernovae were considered the standard candles of the universe — something that also has been called into question in the intervening years by subsequent observations. If these latest findings do indeed cast doubt on the existence of dark energy, I’m sure that Riess and his colleagues at STScI will work to reconcile them with the earlier findings or will begin to search for an alternative explanation. In my experience, they represent the best of their field.

  • Edward

    I do not think that there is malfeasance, but I do think that the astronomical field raised the dark energy hypothesis to something that resembles theory status without first finding real evidence of dark energy. Usually, accepting a hypothesis as thoroughly as astronomers did requires more exploration or experimentation. A theory requires more evidence than we have for dark energy.

    Oh, and look! You have presented yet another reason to suspect that the hypothesis is incorrect.

    At least the big bank theory has the cosmic microwave background to back it up.

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