No, the Universe is not expanding at an accelerated rate...

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Boris2, Oct 24, 2016.

  1. Boris2 Valued Senior Member

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    http://www.sciencealert.com/no-the-universe-is-not-expanding-at-an-accelerated-rate-say-physicists

    Interesting.
     
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  3. paddoboy Valued Senior Member

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    Yes it is already being discussed here.....
    https://www.yahoo.com/news/m/8659d54f-16bc-30bc-af53-8220313a2ce4/ss_accelerating-universe.html
    My comment? New research and much work needing to be done.
    from your link.......
    "Naturally, a lot of work will be necessary to convince the physics community of this, but our work serves to demonstrate that a key pillar of the standard cosmological model is rather shaky," says Sarkar.

    "Hopefully, this will motivate better analyses of cosmological data, as well as inspiring theorists to investigate more nuanced cosmological models."



    The paper:
    http://www.nature.com/articles/srep35596
    Marginal evidence for cosmic acceleration from Type Ia supernovae

    Abstract

    The ‘standard’ model of cosmology is founded on the basis that the expansion rate of the universe is accelerating at present — as was inferred originally from the Hubble diagram of Type Ia supernovae. There exists now a much bigger database of supernovae so we can perform rigorous statistical tests to check whether these ‘standardisable candles’ indeed indicate cosmic acceleration. Taking account of the empirical procedure by which corrections are made to their absolute magnitudes to allow for the varying shape of the light curve and extinction by dust, we find, rather surprisingly, that the data are still quite consistent with a constant rate of expansion.




     
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  5. danshawen Valued Senior Member

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    ""We analysed the latest catalogue of 740 Type Ia supernovae - over 10 times bigger than the original samples on which the discovery claim was based - and found that the evidence for accelerated expansion is, at most, what physicists call '3 sigma'," reports lead researcher, Subir Sarkar, from the University of Oxford."

    Three sigma is still "at most" 99.7% certainty.

    For those looking for actual work, here is some of the cosmology work "needing to be done" in connection with this finding.

    I want everyone to notice something about this finding that seems forgotten in any analysis I've seen so far. ANY Doppler shift measurement is simply a measure of acceleration without regard to assigning it a direction. As such, the evidence found to be 99.7% convincing here could simply mean that the larger population of type 1a supernovae were actually rotating about some central point. Furthermore, if the CMBR is a little "hotter" in the Southern Hemisphere than it is in the North, THAT MEASUREMENT IS ALSO ELIGIBLE TO BE INTERPRETED AS DOPPLER SHIFT, and therefore, we already have found and know the SENSE, DIRECTION, AND CENTER of that rotation. All that needs to be done now is for someone who knows what it is they are doing to correlate the two data sets. The Doppler derived acceleration could simply mean that the whole aggregation of type 1a supernovae are rotating about something, the same way just about everything seems to be doing on scales from galaxies to atomic structure. How hard could it be to find that out? Don't forget to take time dilations into account in your analysis. They will in general be different depending on how far each type 1a supernova is from the center of rotation. On such vast scales, this particular correction cannot be neglected.

    As pointed out (by me) in another thread, conservation of energy is a hard law of physics that cannot be broken unless you are trying to say that the universe at large or dark energy is the perpetual motion machine that creates energy from nothing the way real physics cranks often claim. "Dark energy", if it even exists, must be conserved also. Only our "New Age" or mainstream cosmologists whom I ignore here would claim that it is otherwise.
     
    Last edited: Oct 24, 2016
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  7. The God Valued Senior Member

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  8. Boris2 Valued Senior Member

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  9. The God Valued Senior Member

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    No, it is not mentioned on this thread. If you are referring to Paddoboy post #2, then also it does not mention timojin thread, even though he knew about it.
     
  10. Boris2 Valued Senior Member

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    I took already discussed here to mean this forum as it is not discussed on Yahoo.
     
  11. paddoboy Valued Senior Member

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    Remembering all the hooha after "OPERA" neutrino experiment, claimed that they had achieved FTL results.
    And of course the rather premature announcement by BICEP2....
    Wise as usual to wait until repeat experiments confirm this result.
    Whatever the results of future experiments show and whether any modification to our present accepted cosmology picture is needed, it will be done and achieved by reputable mainstream scientists, just as the two false results above were clarified by mainstream scientists.
     
  12. Spellbound Banned Valued Senior Member

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    Why is dark energy considered mysterious? And does the accelerating one-way expansion imply universes within universes, "meta-verses" in which our universe is but a matrix within such a "super-structure"? And when do the turtles stop? In this instance acceleration would exceed the speed of light, which means the boundary is massless. If the universe is growing, what is it growing into?

    Click here: https://books.google.ca/books?id=S0TVCgAAQBAJ&pg=PA56&lpg=PA56&dq=matter opposite direction decelertion of universe&source=bl&ots=U1pg-kUA_o&sig=H8ds_JQNRLq0jSseNsW3Qt9fNeY&hl=en&sa=X&ved=0ahUKEwi94oycqvnPAhVY42MKHd0uBDkQ6AEIKDAC#v=onepage&q=matter opposite direction decelertion of universe&f=false
     
    Last edited: Oct 26, 2016
  13. Spellbound Banned Valued Senior Member

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    Do you have equations (Friedman etc.) that might mathematically indicate absolute magnitude for expansion? "Extinction by dust" implies that the physical universe will either die or transition. Is this consistent with String theoretical views and the universe as a hologram?
     
    Last edited: Oct 26, 2016
  14. paddoboy Valued Senior Member

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    21,703
    Because we are not sure of the exact nature of it, although the CC of Einstein fame maybe it.
    Not that I am able to envisage: In my opinion, in other words this is just speculation, perhaps the singularity that our universe arose from may have been the arse end of a BH in another Universe, and possibly the singularity regions of BH's in this Universe may lead via wormholes and ERB's to other outpourings of spacetime, creating other universes.
    Good question: We don't know.
    The latest data from WMAP and other experiments, show that our universe is flat to within small tolerances, and probably infinite.
    As per the BB, the universe/spacetime was the evolution of spacetime as we know it, and is all there is: As the universe has no center, [other than the center of our observable universe] it is also expanding into nothing: It is simply expanding. It is all there is within the bounds of our theories at this time.
     
  15. Spellbound Banned Valued Senior Member

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    11. The Telic principle simply asserts that this is the case; the most fundamental imperative of reality is such as to force on it a supertautological, conspansive structure. Thus, the universe “selects itself” from unbound telesis or UBT, a realm of zero information and unlimited ontological potential, by means of telic recursion, whereby infocognitive syntax and its informational content are cross-refined through telic (syntax-state) feedback over the entire range of potential syntax-state relationships, up to and including all of spacetime and reality in general. . . the Extended Superposition Principle, a property of conspansive spacetime that coherently relates widely-separated events, lets the universe “retrodict” itself through meaningful cross-temporal feedback (p. 38)

    From link.
     
  16. paddoboy Valued Senior Member

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  17. danshawen Valued Senior Member

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    This:

    http://cds.cern.ch/record/475494/files/0011070.pdf


    which purports to explain superluminal expansion of the universe in a manner that things in a distant region of space receding superluminally can be observed is bunk because "a region of space that is moving" has no more meaning than dividing a number by zero. If you want us to believe that a region of space can move, then design an experiment that can demonstrate it. You can't. If you could, that demonstration would violate special relativity's edict that no locally performed experiment can determine either absolute motion or a preferred reference frame. And if this were the case, Michelson Moreley or later attempts to determine absolute motion would not have all yielded null results. Suggesting that GR offers a refuge for the idea of superluminal expansion is likewise a cop out. An extreme red shift does not suggest superluminal acceleration to anyone but one of those New Age or conehead cosmologists.

    A fixation on the idea of using the Hubble constant to support superluminal expansion of the universe is akin to a preference for the accuracy of dead reckoning instead of GPS for navigation in the middle of an ocean. That is to say, in a contest of the veracity of Hubble's Law vs. Relativity, Relativity wins every time no contest.

    So, "universe expansion not accelerating" is not really much of a surprise. Never saw a Nobel prize revoked before, but I suppose it's a possibility.
     
    Last edited: Oct 27, 2016
  18. paddoboy Valued Senior Member

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    21,703
    First its spacetime, secondly, just because you fail to understand the deeper universal expansion picture, does not make it bunk.
    Perhaps you need to supply a link/reference or citation supporting your own bunk.
    In the meantime as per the claim of FTL a few years ago, much research is to be done before this finding is verified as presently interpreted.
    I also recall you speaking of Kip Thorne in less then complimentary tones, along with gravitational radiation a while back: Seems like other Tom, Dick's and Harry's, you have a problem with much.
    So why not express your concerns via the proper channels?

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  19. PhysBang Valued Senior Member

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    Nope. Not only nope, but this doesn't even apply to all of the measurement. Not all redshit in these supernovae are Doppler redshift; Doppler redshift is the redshift (or blueshift in some cases) associated with the movement of a supernova with respect to the cosmological mean. This could be due to the peculiar motion of the galaxy or galaxy cluster hosting the supernova or it could be due to the motion of the supernova within that structure. A measurement of Doppler redshift/blueshift is a measurement of the velocity in the direction of the observation. The other sources of redshift/blueshift come from cosmological expansion and the effects of gravity based on mass-energy distribution. Redshift from cosmological expansion is also aligned in the direction of the observation.
    No, for all the reasons listed above.
    Well, since we do actually identify the primary anisotropy in the CMB as due to a Doppler like effect, we do identify that we are moving relative to the cosmological mean in a specific direction. No rotation, no center.

    Welcome to all cosmology since 2003. Seriously, that is what people have been doing and why people believe in dark energy and why this particular study of supernovae is not, on its own, going to convince many people.
    And as pointed out by others, at the cosmological scale, there are many ways to define conservation of energy, not all of which agree and none of which are universally adopted. Like always, danshawen is ignoring the actual science.

    (This is why he has me on ignore, because I actually bring up the science and ask him relevant questions on it.)
     
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  20. PhysBang Valued Senior Member

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    "Extinction by dust" means that light is dimmed by dust between the emitter of light and the device used to measure and record that light.
     
  21. danshawen Valued Senior Member

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    Granted that could be the case. But if there were a center, how could you tell? One end of the sky or hemisphere would be continuously accelerating toward us. The other end of the sky or hemisphere would be continuously accelerating away from us. Is this not what we observe?

    You get a red Doppler shift if something is moving away from you, but also if it is moving, up or down, left or right or any combination of those vector velocities. You get a blue Doppler shift iff something is moving toward you, or else you are moving toward it.

    And you also get a PAIR of Doppler shifts if something is rotating, if you look in the right directions. "Blue vs red" Doppler shift is the same thing as "warmer vs. cooler", and it works exactly the same way for microwave background radiation as it does for visible light or infrared.

    If you and the thing you are observing are in the same inertial frame of reference, you get exactly no Doppler shift.

    And finally, there is a gravitational red Doppler shift associated with general relativistic time dilation, although this is typically a much smaller shift than ones caused by relative motion.

    I'm only suggesting, the DE acceleration, if any actually exists, from type 1a supernovae could simply be a rotation. To answer this question, you would need to explain why should aggregate rotation affect only smaller scales and not the largest? If angular momentum is conserved on one scale but not another, you would have some tall explaining to do.
     
  22. danshawen Valued Senior Member

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    The Hubble expansion would still be observed in the above scenario. Replace the word "blue" with a shift that is just "less red". Now interpreting DE acceleration as rotation works fine as described.

    FTL acceleration because space itself expands is still bunk. That would result in paddoboy's scenario of being red shifted so far, you could not observe anything at all. Just like falling into a black hole, and with the same result.
     
  23. paddoboy Valued Senior Member

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    Rubbish again.
    As I said previously, your apparent less then complimentary tones on Thorne, verging on vitriol, speaks volumes on your knowledge or lack thereof on this subject. That also extended to gravitational radiation.

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    So again, why not express your concerns via the proper channels, because really like a couple of others that frequent science forums, to try and invalidate cosmological theories, your bunkum will wither and fade into oblivion, never to be heard of again.
    Rotational Universe?
    This possibility has been discussed for decades, without any of the problems you claim could be construed with accelerating expansion.
    I did find this.......................
    http://physics.stackexchange.com/questions/1048/what-if-the-universe-is-rotating-as-a-whole


    If you believe wholeheartedly in Mach's principle, then there is no way to test empirically for rotation of the universe as a whole, since there is nothing else for it to be rotating relative to. However, general relativity is not very Machian, and it offers a variety of ways in which an observer inside a sealed laboratory can detect whether the lab is rotating. For example, she can observe the motion of a gyroscope, or measure whether the Sagnac effect is zero. There are alternative theories of gravity, such as Brans-Dicke gravity, that are more Machian than GR,[Brans 1961] and in these theories there is probably no meaningful sense in which the universe could rotate. However, solar-system tests[Bertotti 2003] rule out any significant deviations from GR of the type predicted by Brans-Dicke gravity, so that it appears that the universe really is as non-Machian as GR says it is.

    It is therefore possible according to general relativity to have cosmologies in which the universe is rotating. Historically, one of the earliest cosmological solutions to the Einstein field equations to be discovered was the Gödel metric, which rotates and has closed timelike curves. If we lived in a rotating universe such Gödel's example, the rate of rotation would have to be expressed in terms of angular velocity, not angular momentum. Angular velocity is what is measured by a gyroscope or the Sagnac effect, and GR doesn't even have a definition of angular momentum that applies to cosmological spacetimes.

    A rotating universe does not have to have a center of rotation, and it can be homogeneous. In other words, we could determine a direction in the sky and say that the universe was rotating counterclockwise at a certain rate about the line connecting us to that point on the celestial sphere. However, aliens living somewhere else in the universe could do the same thing. Their line would be parallel to ours, but there would be no way to tell whether one such line was the real center of rotation.

    To find out whether the universe is rotating, in principle the most straightforward test is to watch the motion of a gyroscope relative to the distant galaxies. If it rotates at an angular velocity -ω relative to them, then the universe is rotating at angular velocity ω. In practice, we do not have mechanical gyroscopes with small enough random and systematic errors to put a very low limit on ω. However, we can use the entire solar system as a kind of gyroscope. Solar-system observations put a model-independent upper limit of 10^-7 radians/year on the rotation,[Clemence 1957] which is an order of magnitude too lax to rule out the Gödel metric.

    A rotating universe must have a certain axis of rotation, so it must have a particular type of anisotropy that picks out a certain preferred direction. We can therefore look at the cosmic microwave background and see whether its anisotropy contains a preferred axis.[Collins 1973] Such observations impose a limit that is tighter than provided by solar-system measurements (perhaps 10^-9 rad/yr[Su 2009] or 10^-15 rad/yr[Barrow 1985]), but such limits are model-dependent.

    Because all of the present observation are consistent with zero rotational velocity, it is not possible to attribute any prominent cosmological role to rotation. Centrifugal forces cannot contribute significantly to cosmological expansion, or to the way your head feels when you're hung over.
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    also
    https://arxiv.org/pdf/0902.4575v3.pdf
     
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