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Non-expanding solution to redshift observations

  1. Yes

    11.1%
  2. No

    55.6%
  3. It is worth crunching the numbers to find out.

    33.3%
  1. Aug 20, 2012 #1
    I do not have the solution referenced in the title, but I seriously ask if one could possibly exist.

    Given the observed redshift data, can there be a solution to any mathematical model which DOES NOT result in an expanding universe?

    Credit to user Chronos sig line:
    If a theory appears to be the only one possible, assume you don't understand the problem. - Popper

    Two possible alternative theories to consider in reconciling the data with a non-expanding universe:

    Redshift due to changing propagation of light over the duration of the cosmos.
    The spectral redshift of distant cosmic light sources is presumed to be due to rarefied light carriers (photons); analagous to rarefied sound carriers (air molecules). In lieu of the usual receding train analogy, consider the Doppler effect as it manifests in various materials. http://arstechnica.com/science/2011/03/inverse-doppler-effect/
    Hypothesize that the composition of the early universal was such that the average speed of light through "empty" space was slower than it is through the vacuous "empty" space of the current universe. Assume a smooth slow transition from then to now. Note: "empty" in this context does not necessarily imply vacuum. It is just a label for the transparent column between a distant object and an earthbased observer. Given that hypothesis and a non-expanding universe; it is reasonable to conclude that the light from extremely distant light sources would take longer to arrive at earth than would be expected if the average speed of light through "empty" space were constant. An expected earth based observation based on this hypothesis when looking at extremely distant light sources; would be a shift of characteristic spectral lines in the direction of the red end of the visible spectrum; due to the rarefied arrival of photons traveling at a lower average speed over the entire course of their journey.

    Redshift due to simultaneous contraction of all matter in the universe.
    Hypothesize that all matter everywhere is slowly shrinking at uniform rates. This means that subatomic particles are shrinking but the relative distance between them in an atom remains proportionally consistent. The fundamental forces continue to operate in a consistent manner. Gravity and atomic forces still pull stuff together. All of our tools for measuring would be shrinking too, thus almost everything locally would appear unchanged. One way the shrinking may be observable would be to look deep into the (past)cosmos at the spectra of light generated from the fusion of atoms. In the distant past, the spectra of a given element would result from fusion of larger atoms than the spectra of the same element in the present. Given that everything else is proportional, it might be assumed that the spectra generated from larger identically configured atoms would result in 'slower' but still characteristic spectra. QED redshift.
     
    Last edited: Aug 20, 2012
  2. jcsd
  3. Aug 20, 2012 #2

    bcrowell

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    We have a FAQ about this: https://www.physicsforums.com/showthread.php?t=506994 [Broken]

    Many cosmological theories have been considered. The current standard model of cosmology isn't the only one that was considered a priori to be possible; it's simply the only one that has survived the confrontation with experiment.

    We have a FAQ about this, too: https://www.physicsforums.com/showthread.php?t=511385 [Broken]

    The distinction between this explanation and the standard description is equivalent to a change of coordinates, which in general relativity is unobservable. Your hypothesis is an acceptable way of describing standard cosmology, and it doesn't make any testable predictions that are different from the predictions of standard cosmology.
     
    Last edited by a moderator: May 6, 2017
  4. Aug 20, 2012 #3
    Thank you bcrowell. It is hard to tell from your response where you would land in the poll. "Can a plausible model of redshift data be created without expanding universe?" It appears you would say yes, a plausible model is possible(or they already exist), but they will never produce any testable results. First, would that be an accurate characterization of your position? If so, do you believe it is worth developing such models anyway? I would guess your answer would be no. Your links, which you were a contributor on, seem somewhat nihilist in this area.
    I am of the opinion that while standard models represent the most likely correct answer; it is still vital that slight resources are dedicated to continually maintaining alternate possible, though unlikely and potentially untestable, theories until they are proven impossible. Having these quixotic theories at the ready, constantly updated with current observations may just give someone the added perspective they need to reveal something truly groundbreaking.
     
  5. Aug 20, 2012 #4

    Drakkith

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    Well, everyone has their opinion. I feel it's a waste of time and resources.
     
  6. Aug 21, 2012 #5
    It is not enough to come up with a mechanism that explains observable redshifts without expansion. You also need to be able to explain why general relativity is wrong on cosmological scales.
     
  7. Aug 21, 2012 #6

    mfb

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    How do they differ from a simple coordinate transformation in the big bang + expanding space model?

    If you define "meter" and "second" based on atomic clocks, the size and time of everyday objects and the speed of light have to stay constant, unless physics is really changing (e.g. a variation of the fine-structure constant).
    If you define "meter" and "second" based on CMB photons, the size of everyday objects and the speed of light shrink all the time, but physics stays the same.

    This gets redshifted in expanding spacetime, too.
     
  8. Sep 5, 2012 #7
    Redshift due to simultaneous contraction of all matter in the universe.

    There is a minor difference between the two descriptions that amounts to more than just a change of coordinates.
    What would be the result of this experiment. Equip a spacecraft, bound far from earth, with measurement tools(camera) and a clock. Equip an earth orbiting satellite with identical equipment and synchronize the clocks. Using the spacecrafts' known travel time and instantaneous velocities, integrate the effects of relativity and adjust the clock so that synchronicity is possible).
    Focus both 'observers' on the same distant celestial object and snap a synchronized photo.
    Continue snapping synchronized photos such that the period between photos is equal to the light transit time from distant based observer to the Earth based observer.
    The end result is that you now have 2 sets of photos. Earth Photos EP = {e0, e1, e2, ...} and Distant Photos DP = {d0, d1, d2, ...}where dn and en+1 are photos of the same celestial object depicting the same moment in that celestial object's history.
    However, en+1 will have been taken AFTER dn and thus the instrument that took en+1 (camera frame analogous to measuring stick) has been subjected to the shrinking/expanding for longer than the instrument which took dn.
    Therefore:
    If the universe is expanding but the matter is not, the size of the instruments will not have changed. In photo dn the celestial object will fill more of the frame than in en+1 by that factor attributable to the distance between the observers.

    Presumably, the image size will be unchanged in either case. While the photon size may shrink after leaving it's source, each photon's trajectory should remain about the same on average. If the universe is shrinking, the size of the distant instruments will be larger than the size of the Earth instruments. Therefore, all else being equal, if all matter in the universe is shrinking, the celestial subject in dn should fill less of the frame than expected.

    The other possibility would be if the celestial subject in dn filled more of the frame than expected.

    Could this experiment actually be done with existing data using existing images? The period between photos is not a hard and fast requirement, it just made it easier to explain.

    Dustin Maki
     
  9. Sep 6, 2012 #8

    mfb

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    How do you determine if the distant observer is at rest relative to earth? How do you fix the distance, when the universe is expanding / objects are shrinking?

    This is true in both models.
    The size of a camera does not influence the angle under which objects appear.

    Relative to the timescales and size of space, all our measurements are basically done at a single position in space and time.
     
  10. Sep 6, 2012 #9
    It doesn't matter if the distant observer is at rest relative to earth. All that needs to be known are the relative angles to the subject and the distance from the distant observer to the earth observer at the time the shots are taken. That is, the distance between the point where the distant observer was, and the point where the earth observer is. This will be calculated with unmodified units.

    Yes, "In photo dn the celestial object will fill more of the frame than in en+1 by that factor attributable to the distance between the observers." That is true in both cases, but in the shrinking universe case, the effect will be lessened due to the camera frame being larger at the time the distant photo is taken. Think of it like taking an identical photo but with a camera designed with a larger image sensor. You get the same image, but it falls on a smaller proportion of the image sensor.
     
  11. Sep 6, 2012 #10

    mfb

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    That is not how cameras work - and in fact, they cannot work as you want to. If you scale everything in a camera, you still get a working camera which will take the same images.
    The camera can measure the apparent angle of the object in an objective way.
     
  12. Sep 6, 2012 #11
    Clamtrox, Can I ask what you mean by this and why you think it?

    Regards,

    Noel.
     
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