Tests of Big Bang Cosmology
http://map.gsfc.nasa.gov/universe/bb_tests.html
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
http://map.gsfc.nasa.gov/universe/bb_tests_exp.html
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
http://map.gsfc.nasa.gov/universe/bb_tests_ele.html
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
http://map.gsfc.nasa.gov/universe/bb_tests_cmb.html
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)
https://www.youtube.com/watch?v=_qFacTKNyCA
o Discovery (31 min starting at 6:25 to 37:00)
Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Parameter Results
http://arxiv.org/abs/1212.5226
http://arxiv.org/pdf/1212.5226v3
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
http://arxiv.org/abs/1303.5062
http://arxiv.org/pdf/1303.5062v1.pdf
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
https://www.sciencedaily.com/releases/2017/08/170803120620.htm
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
observatory.
"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."
sam.wormley@gmail.com