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B How to debunk the idea we are the center of the universe

  1. Aug 2, 2017 #1
    My creationist grandpa says that we are at the center of the universe and that other galaxies are in spherical shells around us and claim that this means we are in a special place in the universe.

    Basically he believes in the "quantized redshifts" thing you may or may not have heard of, which basically says that the redshift data of galaxies suggest that every cluster of galaxies are in a spherical shell around us. I'm probably not explaining this very well. Here is a creationist website that goes into details about this http://creation.com/our-galaxy-is-the-centre-of-the-universe-quantized-redshifts-show.

    The thing is I don't know the story here. Is the problem in the math that is being done? Is the problem in the accuracy and precision of the equipment that collected the data? My grandpa in an engineer and has a much better understanding of mathematics then I do. I am just a high school graduate that takes an interest in science on the internet.

    What am I missing? What do I need to know? I have looked for answers debunking this, and haven't really seen anything that I could understand.
     
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  3. Aug 2, 2017 #2

    PeterDonis

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    The basic story is that this phenomenon, quantized redshifts, is not fully understood, and as long as that's the case, people will be able to construct speculative models like those your grandfather believes, which cannot be debunked because there is no well-confirmed theory to use to debunk them. As far as I can tell from a brief search around the Internet, there is not general agreement among astronomers even on the presence of or magnitude of the effect, let alone on possible explanations. So your grandfather is basically picking the explanation he likes best in an area where we don't know for sure what the correct explanation is.
     
  4. Aug 2, 2017 #3
    The idea that other galaxies orbit our Milky Way makes about as much sense as other planets revolving around Earth; it is a fringe theory that will continue to fade away as modern science progresses.

    Here's something you may find interesting:


    https://www.physicsforums.com/threads/great-attractor-and-the-cmb-dipole.903330/
     
  5. Aug 2, 2017 #4

    mfb

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    The good old god of the gaps. You cannot refute it because it is not even an argument.

    We won't understand every single measurement in the foreseeable future, and it is not clear if we will ever do so. You can always pick your favorite thing that is not yet understood and claim "god did it". People did it with the day and night cycle, with the weather, with the planets, with organic chemistry, with species and many more things.
     
  6. Aug 2, 2017 #5

    kimbyd

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    Quantized redshift is basically bunk. Typically what happens is one group of scientists comes up with a statistical test that they claim shows redshift quantization. Then others point out that they missed factor X, Y, or Z, and that once you take that factor into account the quantization disappears. This song and dance seems to crop up once every few years.

    But you'll have a really hard time proving it to his satisfaction. There are, after all, a number of scientific papers that do claim to show quantization. It would be very easy for him to point to one of those. It's much harder to get across the comprehensive body of scientific research that does not support this at all.
     
  7. Aug 2, 2017 #6
    Odd, I was under the impression that we could determine the distance galaxies are away from us with a fair bit of accuracy. Enough that this would be easy to prove or disprove this concept.
     
  8. Aug 2, 2017 #7

    kimbyd

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    Oh, we can determine their distances with a fair bit of accuracy, using a particular definition of distance. The important point is that we could, if we wanted to, use a different measure of distance. In fact, cosmologists use a wide variety of distance measures in practice depending upon the situation.

    The point is not that we have no information about distance, but that there is no fundamental reason to decide that one measure of distance is better than another. This is why we have distance measures that are known by terms like "comoving distance", "angular diameter distance", "luminosity distance", and "parallax distance". Each has a very precise definition, and each can be measured with a high degree of precision given the right conditions. It's also pretty easy to convert one distance to another. But not one of these is the "true" distance, because such a thing doesn't exist in a curved space-time. Cosmologists use whichever distance is most useful for the task at hand.
     
  9. Aug 2, 2017 #8

    Chronos

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    One of the more thorough debunks of redshift periodicity is this one; https://arxiv.org/abs/astro-ph/0506366, Critical Examinations of QSO Redshift Periodicities and Associations with Galaxies in Sloan Digital Sky Survey Data, by Zhang and Tang. The SDSS records the redshift of millions upon millions of galaxies and quasars across more than 1/3 of the night sky, so any objections based on sample size are rendered beyond moot. This is the same source used to construct the 3D map of the universe as depicted here http://www.sdss3.org/press/dr9.php.
     
    Last edited: Aug 2, 2017
  10. Aug 2, 2017 #9
    Now I'm even more confused. The article talking about the redshifts basically implies that galaxies are 3.1 million light years away from us in every direction, then 6.2 million light years away then 9.3 etc. Basically putting us in the middle of many rings of galaxies, ever increasing in size out to at least 300 million light years.

    I'm so confused, it would seem to me either this is or isn't true. Which measure would we use to find out, and why isn't this easy to debunk?
     
  11. Aug 2, 2017 #10

    Bandersnatch

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    No, the creationist article in the OP is just trying to make that impression.
    The idea that redshift is quantized is a statistical one. The hypothesis does not state that there are Ptolemaic-like concentric spheres on which galaxies are embedded, with void between - galaxies are distributed every which way. What is suggested, is that there is some clumping around discrete distances, that is unlikely to be the result of random chance.
    So it's patently not that galaxies are 3.1 million ly away in every direction - just point to the Andromeda, which is some 2.5 Mly away, or take a look at the distribution of galaxies in our Local Group:
    683px-Local_Group.svg.png

    The claim is that once you average over all the distances to all the galaxies, there emerges a pattern of clumping. The problem is, and this is a recurring issue in looking for patterns in statistics, that it's relatively easy to botch the analysis, and end up seeing patterns where there are none.

    Anyway, if your uncle or anyone else is claiming that galaxies are distributed only on spheres of 3.1 Mly radius, then they're wrong.
    If they're claiming there's statistical clumping around certain values, then they're on tenuous grounds evidence-wise - they're not outright wrong (nor right), but their claim is also not so juicy.
     
    Last edited: Aug 2, 2017
  12. Aug 2, 2017 #11

    russ_watters

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    So we have that this "quantized redshift" thing is basically like seeing Jesus in the soap bubbles on your shower curtain, but I have a more direct but different angle:
    If we're not even at the center of the Earth-moon system, much less the solar system, how can we possibly be at the center of the universe?
     
  13. Aug 2, 2017 #12

    kimbyd

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    It's simply not true at all that galaxies are at multiples of that (or any) distance. The reason it's hard to debunk to a person like your grandfather is that confirmation bias is a really powerful motivator, and there are scientific articles that claim that there is some periodicity (note: no scientific articles exist that show perfect periodicity, it's always a statement more like "galaxies are more likely to be found at certain distances than others", as clarified by Bandersnatch above).

    A quick summary:
    1. No scientific article exists that claims that galaxies are always at even multiples of distance. It's always expressed in terms of "more likely".
    2. These patterns disappear when you include lots of data and look at it carefully.
     
  14. Aug 2, 2017 #13

    mfb

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    Even the publication linked at the website only sees a weak correlation after a detailed statistical analysis. It is so weak that you won't see a pattern by eye if you make a plot of the observed distances. And they don't make a plot for this reason.
    As a random example with a plot, check the blue and red lines in the upper graphs here. They are not constant, they have a highly significant periodic oscillation in it (it is the second detected gravitational wave event, black is the contribution from gravitational waves). Does that mean the data points are arranged in separate spikes? Clearly not, and by eye you don't even see that there is something special in the datasets.
     
  15. Aug 2, 2017 #14

    russ_watters

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    I double-like this. I think other posts have said similar things, but not forcefully/unequivocally enough, and that's why the message isn't getting through to the OP. It's a "feature" of science that nothing is ever 100%, but an emphasis on that can make things seem much less sure than they really are.
     
  16. Aug 2, 2017 #15
    My twist is to say "God did it" and wait for scientists to explain how cool and amazing the universe really is. : )
     
  17. Aug 3, 2017 #16

    Chronos

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    It's perfectly ok to say 'god did it', it's another thing to say how. 'God' obviously prefers random distributions, as evidenced in all other sciences [e.g., biology and chemistry]. Why would an omnipotent creator elect to make cosmology such a singular exception to the random order so pervasive in all other sciences?
     
  18. Aug 4, 2017 #17
    One way to debunk the idea that Earth is the center of the Universe is to propose that Mars is the real center, or Pluto for that matter.
    That idea is equally feasible, and as with Earth, it cannot be proven to be false.
     
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