Tests of Big Bang Cosmology
http://edu-observatory.org/olli/tobbc/Week3.html   or   index.html


Tests of Big Bang Cosmology

  The Big Bang Model is supported by a number of important
  observations, each of which are described in more detail
  on separate pages:

  1. The expansion of the universe

  Edwin Hubble's 1929 observation that galaxies were generally
  receding from us provided the first clue that the Big Bang
  theory might be right.

  2. The abundance of the light elements H, He, Li

  The Big Bang theory predicts that these light elements
  should have been fused from protons and neutrons in the
  first few minutes after the Big Bang.

  3. The cosmic microwave background (CMB) radiation

  The early universe should have been very hot. The cosmic
  microwave background radiation is the remnant heat leftover
  from the Big Bang.

  The existence of the CMB radiation was first predicted by
  Ralph Alpher in 1948 in connection with his research on Big
  Bang Nucleosynthesis undertaken together with Robert Herman
  and George Gamow. It was first observed inadvertently in
  1965 by Arno Penzias and Robert Wilson at the Bell Telephone
  Laboratories in Murray Hill, New Jersey. The radiation was
  acting as a source of excess noise in a radio receiver they
  were building. Coincidentally, researchers at nearby
  Princeton University, led by Robert Dicke and including Dave
  Wilkinson of the WMAP science team, were devising an
  experiment to find the CMB. When they heard about the Bell
  Labs result they immediately realized that the CMB had been
  found. The result was a pair of papers in the Astrophysical
  Journal (vol. 142 of 1965): one by Penzias and Wilson
  detailing the observations, and one by Dicke, Peebles, Roll,
  and Wilkinson giving the cosmological interpretation.
  Penzias and Wilson shared the 1978 Nobel prize in physics
  for their discovery.

  Uniform color oval representing the temperature variation
  across the sky of the CMB. Today, the CMB radiation is very
  cold, only 2.725 above absolute zero, thus this radiation
  shines primarily in the microwave portion of the
  electromagnetic spectrum, and is invisible to the naked eye.
  However, it fills the universe and can be detected
  everywhere we look. In fact, if we could see microwaves, the
  entire sky would glow with a brightness that was
  astonishingly uniform in every direction. The picture at
  left shows a false color depiction of the temperature
  (brightness) of the CMB over the full sky (projected onto an
  oval, similar to a map of the Earth). The temperature is
  uniform to better than one part in a thousand! This
  uniformity is one compelling reason to interpret the
  radiation as remnant heat from the Big Bang; it would be
  very difficult to imagine a local source of radiation that
  was this uniform. In fact, many scientists have tried to
  devise alternative explanations for the source of this
  radiation, but none have succeeded.

  These three measurable signatures strongly support the
  notion that the universe evolved from a dense, nearly
  featureless hot gas, just as the Big Bang model predicts.

Back to the Beginning Origins Nova Neil Degrasse Tyson HD (53 min)
  o Discovery (Start 6:25)

Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results

  We present cosmological parameter constraints based on the
  final nine-year WMAP data, in conjunction with additional
  cosmological data sets. The WMAP data alone, and in
  combination, continue to be remarkably well fit by a
  six-parameter LCDM model. When WMAP data are combined with
  measurements of the high-l CMB anisotropy, the BAO scale, and
  the Hubble constant, the densities, Omegabh2, Omegach2, and
  Omega_L, are each determined to a precision of ~1.5%. The
  amplitude of the primordial spectrum is measured to within
  3%, and there is now evidence for a tilt in the primordial
  spectrum at the 5sigma level, confirming the first detection
  of tilt based on the five-year WMAP data. At the end of the
  WMAP mission, the nine-year data decrease the allowable
  volume of the six-dimensional LCDM parameter space by a
  factor of 68,000 relative to pre-WMAP measurements. We
  investigate a number of data combinations and show that their
  LCDM parameter fits are consistent. New limits on deviations
  from the six-parameter model are presented, for example: the
  fractional contribution of tensor modes is limited to r<0.13
  (95% CL); the spatial curvature parameter is limited to
  -0.0027 (+0.0039/-0.0038); the summed mass of neutrinos is
  <0.44 eV (95% CL); and the number of relativistic species is
  found to be 3.84+/-0.40 when the full data are analyzed. The
  joint constraint on Neff and the primordial helium abundance
  agrees with the prediction of standard Big Bang
  nucleosynthesis. We compare recent PLANCK measurements of the
  Sunyaev-Zel'dovich effect with our seven-year measurements,
  and show their mutual agreement. Our analysis of the
  polarization pattern around temperature extrema is updated.
  This confirms a fundamental prediction of the standard
  cosmological model and provides a striking illustration of
  acoustic oscillations and adiabatic initial conditions in the
  early universe.

Planck 2013 results. I. Overview of products and scientific results

  The ESA's Planck satellite, dedicated to studying the early
  universe, was launched on May 2009 and has been surveying the
  microwave and submillimetre sky since August 2009. In March
  2013, ESA and the Planck Collaboration publicly released the
  initial cosmology products based on the first 15.5 months of
  Planck operations, along with a set of scientific and
  technical papers and a web-based explanatory supplement. This
  paper describes the mission and its performance, and gives an
  overview of the processing and analysis of the data, the
  characteristics of the data, the main scientific results, and
  the science data products and papers in the release.

Dark Energy Survey reveals most accurate measurement of 
universe's dark matter

  Dark Energy Survey scientists have unveiled the most
  accurate measurement ever made of the present large-scale
  structure of the universe. These measurements of the amount
  and 'clumpiness' (or distribution) of dark matter in the
  present-day cosmos were made with a precision that, for the
  first time, rivals that of inferences from the early
  universe by the European Space Agency's orbiting Planck

  "This result is beyond exciting," said Scott Dodelson of
  Fermilab, one of the lead scientists on this result. "For
  the first time, we're able to see the current structure of
  the universe with the same clarity that we can see its
  infancy, and we can follow the threads from one to the
  other, confirming many predictions along the way."