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B Theory that challenges Einstein's physics could soon be put to rest

  1. Nov 28, 2016 #1


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    Surly the variable speed of light is a dead dog, this article says it is not, and the theory can be tested

    But some researchers have suggested that the speed of light could have been much higher in this early universe. Now, one of this theory's originators, Professor João Magueijo from Imperial College London, working with Dr Niayesh Afshordi at the Perimeter Institute in Canada, has made a prediction that could be used to test the theory's validity..

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  3. Nov 28, 2016 #2


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    Here's the arxiv link for the source paper:

    Seems interesting, and it's good that they make some very definite predictions. But it won't be easy to distinguish this model from inflation. I think the main difficulty with this model being accepted will be that they don't have a reasonable mechanism by which the speed of light might vary.
  4. Nov 28, 2016 #3
    What's the vetting process for a new theory like this? Do authors still go through the peer review/journal publishing process or is it all about citations these days (this paper currently has 1). I ask because I've read Sean Carroll speak negatively about the journal publication process as being too "20th century".
  5. Nov 28, 2016 #4


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    There is no formal vetting process. It's all a matter of convincing other scientists. In general, the way to do that is to have multiple different types of evidence that converge on the same picture.

    With this particular model, for example, even if further experiments dramatically narrowed the measurements of the spectral index (and related parameters), and the narrowed results still fit this model, it will not convince a large number of physicists just because there isn't independent confirmation. If somebody were to use this model to come up with a completely different observation or experiment that could test the model in a different way, then they would be at the point of convincing some people.

    If you want a picture of how this is done, take a look at this essay:

    The essay goes over a bunch of different pieces of evidence. In particular, many of the types of evidence use entirely different sorts of observations, varying from the abundances of light elements to the variations on the CMB to the typical distances between galaxies, to name a few. The fact that these very different types of measuring the same model agree with one another gives us confidence in the model.

    Note that inflation also has similar observational difficulties (in that it's difficult to come up with independent evidence). The main reason why it's the preferred model is because the model behind it is a natural extension of existing high-energy physics.
  6. Nov 29, 2016 #5


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    Science is ruled by consensus. A new theory evolves much like ancient religions. It begins with an idea and a small group of apostles who spread the word then peaks in a vast swarm of adherents. It transforms via an apostate who overturns the establishment view with a new idea and predictions that accomodate both past and future observations.
  7. Nov 29, 2016 #6


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    Eh. There's frequently not any one single person pushing a new theory. Not any longer, anyway. Physics these days is generally done by large teams of people, or at the very least large numbers of distributed people. The last example of something like this happening was probably General Relativity. Quantum Mechanics, for example, wasn't led by any one single physicist. Neither were the later relativistic additions to quantum mechanics that led to the development of the Standard Model of Particle Physics. The discoveries of dark matter and dark energy were also large, combined efforts by many people with no single scientist standing out among them.

    New discoveries aren't typically led by a single person any longer because if they were that simple, they would have been discovered long ago.
  8. Nov 29, 2016 #7
    Doesn't loop quantum gravity not only allow but requires the speed of light to vary?
  9. Nov 29, 2016 #8


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    From what I can tell, LQG requires that different wavelengths of light travel at different speeds. This isn't the same thing as the speed of light changing, but rather that very high-energy light doesn't respect Lorentz invariance.
  10. Dec 27, 2016 #9
    Wow! Was not aware of the process. To clarify, before Copernicus the scientific consensus was the universe was centered around the earth. Is that all it takes to become mainstream theory? I ask because mainstream theory is the boundary on this forum.
    Thanks for the information.
  11. Dec 27, 2016 #10

    Vanadium 50

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    Yes. Of course, the fact that you have to reach back almost 500 years says something. And there are plenty of sites that will answer your own questions with crackpot woo. And yet you are here. That says something too.
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