The Universe has no Direction:

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Sep 22, 2016.

  1. paddoboy Valued Senior Member

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    Scientists confirm the universe has no direction
    September 22, 2016 by Hayley Dunning

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    The universe is not spinning or stretched in any particular direction, according to the most stringent test yet.


    Looking out into the night sky, we see a clumpy universe: planets orbit stars in solar systems and stars are grouped into galaxies, which in turn form enormous galaxy clusters. But cosmologists assume this effect is only local: that if we look on sufficiently large scales, the universe is actually uniform.

    The vast majority of calculations made about our universe start with this assumption: that the universe is broadly the same, whatever your position and in whichever direction you look.

    If, however, the universe was stretching preferentially in one direction, or spinning about an axis in a similar way to the Earth rotating, this fundamental assumption, and all the calculations that hinge on it, would be wrong.

    Now, scientists from University College London and Imperial College London have put this assumption through its most stringent test yet and found only a 1 in 121,000 chance that the universe is not the same in all directions.



    Read more at: http://phys.org/news/2016-09-scientists-universe.html#jCp
     
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  3. paddoboy Valued Senior Member

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    https://arxiv.org/pdf/1605.07178v2.pdf


    How isotropic is the Universe?

    A fundamental assumption in the standard model of cosmology is that the Universe is isotropic on large scales. Breaking this assumption leads to a set of solutions to Einstein’s field equations, known as Bianchi cosmologies, only a subset of which have ever been tested against data. For the first time, we consider all degrees of freedom in these solutions to conduct a general test of isotropy using cosmic microwave background temperature and polarization data from Planck. For the vector mode (associated with vorticity), we obtain a limit on the anisotropic expansion of (σV /H)0 < 4.7 × 10−11 (95% CI), which is an order of magnitude tighter than previous Planck results that used CMB temperature only. We also place upper limits on other modes of anisotropic expansion, with the weakest limit arising from the regular tensor mode, (σT,reg/H)0 < 1.0 × 10−6 (95% CI). Including all degrees of freedom simultaneously for the first time, anisotropic expansion of the Universe is strongly disfavoured, with odds of 121,000:1 against.


    Conclusions:
    In this work, we put the assumption that the Universe expands isotropically to its most stringent test todate. For the first time, we searched for signatures of the most general departure from isotropy that preserves homogeneity in an open or flat universe, without restricting to specific degrees of freedom. We have remodeled existing frameworks to analyze CMB polarization data in addition to temperature, allowing us to place the tightest constraints possible with the current CMB data. We find overwhelming evidence against deviations from isotropy, placing simultaneous upper limits on all modes for the first time, and improving Planck constraints on vorticity by an order of magnitude.
     
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  5. PhysBang Valued Senior Member

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    Nice to see attempts to justify the core assumptions of cosmology as much and as directly as possible.
     
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  7. SimonsCat Registered Member

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    Their work was flawed from the onset since they never took into consideration dark flow, which would put considerable question over some of their statements about complete homogeneity in not only distribution of matter, but also their motions.
     
  8. SimonsCat Registered Member

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    hence the statement:

    ''The universe is not spinning or stretched in any particular direction, according to the most stringent test yet.''

    Has to be sloppy work, based on dark flow, which is evidence completely to the contrary, since dark flow can be easily translatable to the residual spin of a universe. The universe doesn't spin nearly as fast today and there are reasons for that which were investigated to great depth by Hoyle and Narlikar.
     
  9. paddoboy Valued Senior Member

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    Dark flow as of today, is simply a hypothetical entity fabricated to explain an as yet unexplained peculiar galaxy cluster flow......and obviously to put it down to any universal angular momentum, is also rather hypothetical at this stage.
    https://www.nasa.gov/centers/goddard/news/releases/2010/10-023.html
    Mysterious Cosmic 'Dark Flow' Tracked Deeper into Universe
    03.10.10


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    The Coma Galaxy Cluster, also known as Abell 1656, is more than 300 million light-years away and is named for its parent constellation, Coma Berenices. It appears to participate in the dark flow. Credit: Jim Misti (Misti Mountain Observatory)

    › Larger image
    › Additional images from Goddard SVSDistant galaxy clusters mysteriously stream at a million miles per hour along a path roughly centered on the southern constellations Centaurus and Hydra. A new study led by Alexander Kashlinsky at NASA's Goddard Space Flight Center in Greenbelt, Md., tracks this collective motion -- dubbed the "dark flow" -- to twice the distance originally reported.

    "This is not something we set out to find, but we cannot make it go away," Kashlinsky said. "Now we see that it persists to much greater distances -- as far as 2.5 billion light-years away." The new study appears in the March 20 issue of The Astrophysical Journal Letters.

    The clusters appear to be moving along a line extending from our solar system toward Centaurus/Hydra, but the direction of this motion is less certain. Evidence indicates that the clusters are headed outward along this path, away from Earth, but the team cannot yet rule out the opposite flow. "We detect motion along this axis, but right now our data cannot state as strongly as we'd like whether the clusters are coming or going," Kashlinsky said.

    The dark flow is controversial because the distribution of matter in the observed universe cannot account for it. Its existence suggests that some structure beyond the visible universe -- outside our "horizon" -- is pulling on matter in our vicinity.

    Cosmologists regard the microwave background -- a flash of light emitted 380,000 years after the universe formed -- as the ultimate cosmic reference frame. Relative to it, all large-scale motion should show no preferred direction.

    The hot X-ray-emitting gas within a galaxy cluster scatters photons from the cosmic microwave background (CMB). Because galaxy clusters don't precisely follow the expansion of space, the wavelengths of scattered photons change in a way that reflects each cluster's individual motion.

    This results in a minute shift of the microwave background's temperature in the cluster's direction. The change, which astronomers call the kinematic Sunyaev-Zel'dovich (KSZ) effect, is so small that it has never been observed in a single galaxy cluster.

    But in 2000, Kashlinsky, working with Fernando Atrio-Barandela at the University of Salamanca, Spain, demonstrated that it was possible to tease the subtle signal out of the measurement noise by studying large numbers of clusters.

    In 2008, armed with a catalog of 700 clusters assembled by Harald Ebeling at the University of Hawaii and Dale Kocevski, now at the University of California, Santa Cruz, the researchers applied the technique to the three-year WMAP data release. That's when the mystery motion first came to light.

    The new study builds on the previous one by using the five-year results from WMAP and by doubling the number of galaxy clusters.

    "It takes, on average, about an hour of telescope time to measure the distance to each cluster we work with, not to mention the years required to find these systems in the first place," Ebeling said. "This is a project requiring considerable followthrough."

    According to Atrio-Barandela, who has focused on understanding the possible errors in the team's analysis, the new study provides much stronger evidence that the dark flow is real. For example, the brightest clusters at X-ray wavelengths hold the greatest amount of hot gas to distort CMB photons. "When processed, these same clusters also display the strongest KSZ signature -- unlikely if the dark flow were merely a statistical fluke," he said.

    In addition, the team, which now also includes Alastair Edge at the University of Durham, England, sorted the cluster catalog into four "slices" representing different distance ranges. They then examined the preferred flow direction for the clusters within each slice. While the size and exact position of this direction display some variation, the overall trends among the slices exhibit remarkable agreement.

    The researchers are currently working to expand their cluster catalog in order to track the dark flow to about twice the current distance. Improved modeling of hot gas within the galaxy clusters will help refine the speed, axis, and direction of motion.

    Future plans call for testing the findings against newer data released from the WMAP project and the European Space Agency's Planck mission, which is also currently mapping the microwave background.

    https://www.nasa.gov/centers/goddard/news/releases/2010/10-023.html
     
    Last edited: Jan 21, 2017
  10. SimonsCat Registered Member

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    213
    I don't accept it is hypothetical, it has been varified in a number of independent tests.
     
  11. SimonsCat Registered Member

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    213
    Don't get me wrong, there were people who wanted to give it some blows. Take this from wiki:

    ''In 2013, data from the European Space Agency's Planck satellite was claimed to show no statistically significant evidence of existence of dark flow.[5][14] However, another analysis by a member of the Planck collaboration, Fernando Atrio-Barandela, suggested the data were consistent with the earlier findings from WMAP''
     
  12. paddoboy Valued Senior Member

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    http://www.earlyuniverse.org/is-the-universe-rotating/
    extract:
    So, is the Universe rotating? Well, probably not. It is only in the unphysical scenario that we find evidence for a Bianchi component. In the physical scenario we find no need to include Bianchi models.

    However, only very simple Bianchi models have been compared to the data so far. There are more sophisticated Bianchi models that more accurately describe the physics involved and could perhaps even provide a better explanation of CMB observations.

    We’re looking into it!
    http://www.earlyuniverse.org/is-the-universe-rotating/
     
  13. SimonsCat Registered Member

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    213
    There is more evidence than just dark flow you know. Most galaxies have a handedness to their spin and the most natural model to explain how this can be so, is a rotating Godel universe with a primordial magnetic field. So the idea is that there is a specific handedness because very early on galaxies aligned their spin with the universe.

    http://physicsworld.com/cws/article/news/2011/jul/25/was-the-universe-born-spinning
     
  14. SimonsCat Registered Member

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    213
    a little like how an electron aligns itself to a magnetic field in a Stern-Gerlach experiment.
     
  15. paddoboy Valued Senior Member

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    https://arxiv.org/pdf/1412.1529v4.pdf

    DETECTABILITY OF COSMIC DARK FLOW IN THE TYPE IA SUPERNOVA REDSHIFT-DISTANCE RELATION
    24 May 2016




    ABSTRACT
    We re-analyze the detectability of large scale dark flow (or local bulk flow) with respect to the CMB background based upon the redshift-distance relation for Type Ia supernovae (SN Ia). We made two independent analyses: one based upon identifying the three Cartesian velocity components; and the other based upon the cosine dependence of the deviation from Hubble flow on the sky. We apply these analyses to the Union2.1 SN Ia data and to the SDSS-II supernova survey. For both methods, results for low redshift, z < 0.05, are consistent with previous searches. We find a local bulk flow of vbf ∼ 300 km s−1 in the direction of (l, b) ∼ (270, 35)◦ . However, the search for a dark flow at z > 0.05 is inconclusive. Based upon simulated data sets, we deduce that the difficulty in detecting a dark flow at high redshifts arises mostly from the observational error in the distance modulus. Thus, even if it exists, a dark flow is not detectable at large redshift with current SN Ia data sets. We estimate that a detection would require both significant sky coverage of SN Ia out to z = 0.3 and a reduction in the effective distance modulus error from 0.2 mag to . 0.02 mag. We estimate that a greatly expanded data sample of ∼ 104 SN Ia might detect a dark flow as small as 300 km s−1 out to z = 0.3 even with a distance modulus error of 0.2 mag. This may be achievable in a next generation large survey like LSST.



    CONCLUSION:
    We have made two independent analyses of both the Union2.1 and SDSS-II SN Ia redshift-distance relation. For the Union2.1 data we have shown that a statistically significant bulk flow can be detected in the low redshift (z < 0.05) subset. However, in the high redshift (z > 0.05) subset, at best only a marginal detection of a dark flow can be made. This is consistent with previous attempts as summarized in Table 2. On the basis of a statistical sampling of simulated low redshift data sets, with and without various dark flow velocities, we confirm that the detection of a bulk flow of ∼ 300 km s−1 is statistically significant at a better than the 99% confidence limit out to a redshift of z < 0.05. However, a similar analysis shows that no dark flow could be detected in the SDSS-II sample even if a dark flow were present. Moreover, we have shown that it is difficult to detect a dark flow velocity of vbf . 2000 km s −1 in the current high redshift Union2.1 data subset. Hence, a similar dark flow velocity to that observed at low redshifts (i.e. < 500 km s−1 ) is not detectable at the present time. The reason that the dark flow is difficult to detect for z > 0.05 can be traced to the large errors in the determined distance moduli of the SN Ia data. For a fixed error in the distance modulus, the actual error in the velocity increases with redshift. From repeated analyses similar to those of Figs. 5, 8, and 10 it was determined that the σv from the error in the distance modulus σµ, should be . vdf in order to detect a dark flow. Some improvement in the distance modulus uncertainties may come from new methods of standardizing SNe Ia, e.g. via the “twins” method of the Supernova Factory (Fakhouri et al. 2015) which reduces the intrinsic dispersion to 0.08 magnitude. Here, however, we have also explored the possibility that increasing the number of supernovae spread over the sky will reduce the uncertainty in the mean distance modulus sufficient to detect a weak dipole signature of a dark flow. The statistical uncertainty in distance estimation will go down as more, well-calibrated, supernovae are cataloged, until a systematic error limit is reached. That systematic floor is expected to be of order 0.02 mag (Betoule et al. 2014), which would be sufficient for a sensitive test of the dark flow. Moreover, we point out that the desired sample size and sky coverage may be achievable with the Large Synoptic Survey Telescope (LSST). Its photometric reliability should be 10 mmag across the whole sky (Ivezic et al. 2008) possibly giving an acceptable observing error. For such a sample, the average distance errors may be suf- ficiently well determined, although the sky distribution might expose unknown issues. Moreover, it will be a long time before a sufficient number of accurate spectroscopic follow-up redshifts are obtained. Also, for any future all sky survey, and particularly in the case of a 1/2 sky survey like LSST, one should explore the dependence of where on the sky one has sensitivity to detecting structure based on the sampling density as described in Weyant et al. (2011).
     
    Last edited: Jan 22, 2017
  16. paddoboy Valued Senior Member

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    https://arxiv.org/pdf/1508.01214v1.pdf

    Constraints on the birth of the universe and origin of cosmic dark flow:
    5 Aug 2015


    We summarize three recent efforts to constrain the first few moments of cosmic creation before and during the epoch of inflation. We consider two means to explain a slight dip in the power spectrum of the cosmic microwave background for multipoles in the range of ` = 10 − 30 from both the Planck and WMAP data. We show that such a dip could be the result of resonant creation of a massive particle that couples to the inflaton field. For best-fit models, the epoch of resonant particle creation reenters the horizon at wave numbers of k∗ ∼ 0.00011 ± 0.0004 (h Mpc−1 ). The amplitude and location of these features correspond to the creation of a number of degenerate fermion species of mass ∼ 15/λ3/2 mpl during inflation where λ is the coupling constant between the inflaton field and the created fermion species. Alternatively, one can explain the existence of such a dip as due to a jump in the inflation generating potential. We show that such a jump can also resolve the excessively large dark flow predicted from the M-theory landscape. Finally, we summarize our efforts to quantify constraints on the cosmic dark flow from a new analysis of the Type Ia supernova distance-redshift relation.



     
  17. Xelasnave.1947 Valued Senior Member

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    I find all of this most interesting.
    May I ask do you know anything about galaxy line up.
    I have read that some observation showed galaxies lining up like "beads on a string".
    This would seem to fit a sort of handyness.
    If such a line up is universal that would be most interesting.
    Thanks for you posts I find them most interesting.
    Alex
     
  18. SimonsCat Registered Member

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    213
    Hello again,

    as of such, I do not believe this primordial magnetic field ''lined galaxies up'', only their respect spins lined up with an early rotating universe, like how protons and neutrons align their spin to the atoms spin. Instead, what this ''spooky alignment'' is, I suspect, a large scale structure due to perhaps. dark matter. This is only an idea - there is clearly other theories that can be explored.
     
  19. SimonsCat Registered Member

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    213
    It might interest you to know Xelasnave, that there is also a spooky alignment of quasars spanning billions of light years.
     
  20. Xelasnave.1947 Valued Senior Member

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    Thank you.
    The implications are...they relate to each other or they relate to a "structure" of space.
    Thank you.
    Alex
     
  21. SimonsCat Registered Member

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    Probably are related yes.
     

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