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Million Galaxy Study Yields Improved Cosmic Creation Model

By Hugh Ross - April 23, 2018
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The more we learn about the universe the more we gain confidence in the biblically predicted big bang creation model1. In the most recent issue of the Astrophysical Journal, a team of nine South Korean and Chinese astronomers performed a clustering analysis of 1,133,326 galaxies from the Sloan Digital Sky Survey Data Release 12 to achieve the most precisely defined and constrained cosmic creation model to date.2

The galaxies the nine astronomers analyzed spanned distances ranging from 1.9–7.5 billion light-years. Specifically, the nine astronomers established the most detailed and precise constraints to date on the properties of the universe’s cosmic mass density and dark energy density. They did this by applying the Alcock-Paczynski test on their very large sample of galaxies. What follows in the next several paragraphs is a somewhat technical explanation, but the details help establish the big bang implications.

In 1979, astronomers Charles Alcock and Bohdan Paczynski published a paper in Nature in which they developed a technique for measuring the cosmic expansion rate, the nature of dark energy, and the spatial geometry of the universe that was independent of the evolutionary history of galaxies.3 This evolution-free test measured the distances to galaxies by comparing the measured angular sizes of galaxies to their sizes determined by the differences in redshifts from the near sides of the galaxies to the far sides.

The Alcock-Paczynski test was not applied until recently because it requires the telescope instrumentation to measure redshifts to extremely high precision. Such precision redshift measuring capability was not possible until just a few years ago.

The Alcock-Paczynski test works well if there is no preferential alignment of galaxies either along or perpendicular to our line-of-sight. Such preferential alignment can be effectively eliminated with a large enough sample of galaxies and galaxy clusters. However, the motions of galaxies are not purely determined by the cosmic expansion rate. Overlapping a galaxy’s velocity due to the cosmic expansion rate is a much smaller, but not trivial, movement of the galaxy generated by its gravitational interactions with nearby massive galaxies. All Alcock-Paczynski tests inevitably are affected by such peculiar motions of galaxies.

The nine astronomers found a way to minimize the effect of peculiar galaxy motions. They achieved this minimization through a statistical analysis of a very large sample of galaxies spanning both a wide range of redshifts and a wide range of galaxy cluster sizes. The Data Release 12 of the Sloan Digital Sky Survey of galaxies delivered the very large sample of galaxies that they needed. In a previous paper, the team demonstrated how their analysis gave them high-precision cosmological constraints.4 In their most recent paper, the team added an improved methodology that gave them a more accurate and reliable determination of the probable errors in their measurements of the cosmological parameters.

Combining their analysis of the Alcock-Paczynski effect on 1,133,326 galaxies from the Sloan Digital Sky Survey Data Release 12 with data from the Planck and WMAP maps of the cosmic microwave background radiation, the baryon-acoustic oscillations, the type Ia supernovae, and the Cepheid variable stars, the nine astronomers produced the following determinations of the cosmic mass density and the nature of cosmic dark energy:5
Ωm = 0.301 ± 0.008
w0 = -1.042 ± 0.067
wa = -0.07 ± 0.29

Ωm = 0.301 means that 30.1 percent of the total cosmic density is comprised of matter. Since the universe’s geometry measures flat to four places of the decimal, the cosmic dark energy density, ΩΛ = 1.000 – 0.301 = 0.699. If dark energy is entirely explained by the cosmological constant, then w0 exactly = -1.0 and wa (the first derivative of w0, a measure of possible change in w0) exactly = 0. That w0 = -1.042 ± 0.067 and wa = -0.07 ± 0.29 implies that—more strongly than any previous measurement—the accelerated expansion of the universe is driven by the cosmological constant or some other dark energy component that has no evolution.

In the fourth edition of The Creator and the Cosmos that we released last month, I cited the best measurements to date of the cosmic mass density and the cosmic dark energy density. Those measurements were Ωm = 0.2934 ± 0.0107 and ΩΛ = 0.707 ± 0.012.6 Compared to the determinations by the nine astronomers, the measurements are remarkably consistent. This consistency, together with the greater precision of the new determinations, demonstrates that we are fully justified in being increasingly confident in the biblically predicted big bang creation model.

Endnotes
  1. Hugh Ross and John Rea, “Big Bang—The Bible Taught It First,” in Hugh Ross, The Creator and The Cosmos: How the Latest Scientific Discoveries Reveal God, 4th ed. (Covina, CA: RTB Press, 2018), 25–31.
  2. Xiao-Dong Li et al., “Cosmological Constraints from the Redshift Dependence of the Alcock-Paczynski Effect: Dynamical Dark Energy,” Astrophysical Journal 856 (April 1, 2018): id. 88, doi:10.3847/1538-4357/aab42e.
  3. Charles Alcock and Bohdan Paczynski, “An Evolution Free Test for Non-Zero Cosmological Constant,” Nature 281 (October 4, 1979): 358–59, doi:10.1038/281358a0.
  4. Xiao-Dong Li et al., “Cosmological Constraints from the Redshift Dependence of the Alcock-Paczynski Effect: Application to the SDSS-III BOSS DR12 Galaxies,” Astrophysical Journal 832 (December 1, 2016): id. 103, doi:10.3847/0004-637X/832/2/103.
  5. Xiao-Dong Li et al., “Cosmological Constraints from the Redshift Dependence of the Alcock-Paczynki Effect: Dynamical Dark Energy,” 5.
  6. Ross, The Creator and the Cosmos, 50–53.

Category
  • Universe Design
  • Dark Energy & Dark Matter
  • Laws of Physics
  • Big Bang Theory
Tags
  • Sloan Digital Sky Survey
  • Cubic Galileon Gravity Model
  • Creation Model
  • Cosmological Constant
  • Cosmic Mass Density
  • Big Bang
  • Alcock-Paczynski Effect
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