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Does Fine Structure Constant Vary From Place to Place?

  1. Nov 3, 2011 #1

    Dotini

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    http://www.swinburne.edu.au/chancel.../10/natures-laws-may-vary-across-the-universe

    One of the laws of nature may vary across the Universe, according to a study published today in the journal Physical Review Letters.

    One of the most cherished principles in science - the constancy of physics - may not be true, according to research carried out at the University of New South Wales (UNSW), Swinburne University of Technology and the University of Cambridge.

    The study found that one of the four known fundamental forces, electromagnetism - measured by the so-called fine-structure constant and denoted by the symbol ‘alpha' - seems to vary across the Universe.

    "The results astonished us," said Professor Webb. "In one direction - from our location in the Universe - alpha gets gradually weaker, yet in the opposite direction it gets gradually stronger."

    "The discovery, if confirmed, has profound implications for our understanding of space and time and violates one of the fundamental principles underlying Einstein's General Relativity theory," Dr King added.



    Apparently these findings are based on observations of quasars. It may be prudent to suspect their observations were defective in some way.

    Respectfully submitted,
    Steve
     
    Last edited: Nov 3, 2011
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  3. Nov 3, 2011 #2

    Chronos

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    This has been tested and debated for years, not just with astrophysical measurements, but, a number of methods - atomic clocks, the Oklo natural reactor and meteorites to name a few. For a recent review paper see
    arXiv:1111.0092 - The Constancy of the Constants of Nature: Updates
    In a nutshell, virtually all data sources to date indicate any variation over time is vanishingly small. It is worth mentioning that if the fine structure constant varied significantly over the age of the universe, distant stars would behave oddly and in ways that would surely be detectable with modern equipment.
    The conclusion reached in the article you linked is a bit aggregious. Asserting variation in the fine structure constant varies over time and direction is very bold and has plenty of implications - not the least of which would be falsification of the the Copernican Principle. The odd stellar behavior previously mentioned would be exacerated by direction as well as time. I suspect a systematic error is unaccounted for in their results. Bold claims require bold evidence.
     
  4. Nov 3, 2011 #3

    Dotini

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    Bejeebers! I honestly had no idea the matter was so serious.

    Most respectfully,
    Steve
     
  5. Nov 5, 2011 #4
    Except that they did not measure alpha, but interpreted observations as if were due to a changing alpha. That is different.
     
  6. Nov 5, 2011 #5

    Dotini

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    http://en.wikipedia.org/wiki/Quasar
    Quasars show a very high redshift, which is an effect of the expansion of the universe between the quasar and the Earth.[2] They are among the most luminous, powerful, and energetic objects known in the universe. They tend to inhabit the very centers of active young galaxies and can emit up to a thousand times the energy output of the Milky Way. When combined with Hubble's law, the implication of the redshift is that the quasars are very distant—and thus, it follows, objects from much earlier in the universe's history. The most luminous quasars radiate at a rate that can exceed the output of average galaxies, equivalent to one trillion suns.

    Some quasars display changes in luminosity which are rapid in the optical range and even more rapid in the X-rays. Because these changes occur very rapidly they define an upper limit on the volume of a quasar; quasars are not much larger than the Solar System.[4] This implies an astonishingly high energy density.[5] The mechanism of brightness changes probably involves relativistic beaming of jets pointed nearly directly toward us.




    Quasars surely "behave oddly". It's no wonder the people who look at them come up with some pretty odd ideas.

    Respectfully,
    Steve
     
  7. Nov 6, 2011 #6

    Chronos

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    I fail to comprehend your point.
     
  8. Nov 6, 2011 #7

    Dotini

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    ^^^^This sounds very anti-Copernican.
    If all these these quasars studied are pointing at us, surely there must be gazillions of them pointing elsewhere?

    If paid, professional astronomers are openly publishing anti-Copernican heresy, it demands a clear explanation of why it is not, or else they must be harried out of business, right?

    Respectfully,
    Steve
     
    Last edited: Nov 6, 2011
  9. Nov 6, 2011 #8

    D H

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    Do the math. Surely there must be tens of million to billions of them pointing elsewhere. The current estimate is that there are 350 billion galaxies in the visible universe, the vast majority of which we are seeing when they were very young (i.e., right when galaxies with active galactic nuclei were at their peak).
     
  10. Nov 7, 2011 #9

    Chronos

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    Just how many quasars was the study result based on? I assume it was less than 350 billion.
     
  11. Nov 7, 2011 #10

    D H

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    A much smaller number. It was a bit more than 100.

    You are missing Dotini's point, and the point of my rebuttal to his point. Dotini was expressing incredulity at the very concept of quasars being active galactic nuclei (AGN) one of whose relativistic jets just happens to be "pointed nearly directly toward us." That is exactly the currently accepted explanation of quasars. Most of the energy radiated by an AGN is restricted to a pair of highly collimated jets. We will see what appears to be an anomalously bright object if one of those jets happen to be aimed more or less toward us. A pair of jets each with an angular diameter of 16 degrees are highly collimated compared to a uniform radiation over 4 pi steradians. Some quasars appear to be even more highly collimated; some jets have an angular diameter of only 5 degrees. This tight a jet means energy is concentrated in about 1/1000 of the sky.

    Assuming there are one million quasars (the current catalog has about 200,000), and assuming all of them have jets collimated to 5 degrees means there are about one billion such AGNs overall. Using a lower set of number (our catalog is more or less complete, and jets are collimated to 20 degrees) yields about 13 million such AGN overall. So, somewhere between 10 million and a billion AGNs overall. This result is not out of line with the 350 billion estimated galaxies in the universe.
     
  12. Nov 7, 2011 #11

    D H

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    Given that this result is now in the news and may have broader implications to physics and cosmology, the rules applied to the purportedly faster than light neutrinos also applies here.

    Before posting in this thread, we'd like to ask readers to read three things:

    1. The https://www.physicsforums.com/showthread.php?t=414380". Don't forget the section on overly speculative posts.
    2. The paper http://arxiv.org/abs/1008.3907
    3. The previous posts in this thread
     
    Last edited by a moderator: Apr 26, 2017
  13. Nov 7, 2011 #12

    D H

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    These results have been published in a peer-reviewed physics journal, and a rather respectable one at that. The paper in question is Phys. Rev. Lett. 107, 191101 (2011).

    An arxiv preprint is at http://arxiv.org/abs/1008.3907

    Here is an interview with one of the authors of the paper: http://www.sciencefriday.com/program/archives/201111043 [Broken].
     
    Last edited by a moderator: May 5, 2017
  14. Nov 9, 2011 #13

    Dotini

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    http://www.astronomy.swin.edu.au/~mmurphy/res.html [Broken]

    A summary of the research from Michael Murphy's site, with numerous valuable links.

    Respectfully submitted,
    Steve
     
    Last edited by a moderator: May 5, 2017
  15. Nov 10, 2011 #14
    Not only the Copernican principle but its realization in cosmology:the Cosmological principle, would be in serious trouble as this variation breaks both isotropy and homogeneity.
     
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