The Wilkinson Microwave Anisotropy Probe (WMAP) has been gathering data regarding the earliest moments of the universe since it’s launch on June 30, 2001.

 WMAP spacecraft diagram.jpg

NASA this week released five years of data collected by WMAP that includes three major findings:

  1. New evidence that cosmic neutrinos fly all around the universe penetrating everything in their path;
  2. Clear evidence the first stars created a cosmic ‘fog’ after more than 400 million years; and,
  3. New constraints on the expansion of the universe in the first trillionth of second of birth.

WMAP measures the oldest light left over from the beginnings of the universe. This light lost Piechartenergy as the universe expanded over the last 13.7 billion years such that now the energy is seen as microwaves, which the WMAP is designed to detect and measure. Microwave light seen by WMAP when the universe was only 380,000 years old shows neutrinos constituted 10% of the universe, photons 15%, dark matter 63%, atoms 12% and not much dark energy.

WMAP data shows the present universe to consist of 4.6% atoms, 23% dark matter, 72% dark energy and less than 1% neutrinos. Neutrinos were so plentiful in the early universe they affected the microwaves that WMAP sees suggesting that with 99.5% confidence, a cosmic neutrino background element was present.

WMAP has also found new insights into when the first generation of stars began. The glow from these stars created a thin fog consisting of electrons in their surrounding gas that scatters microwaves, like light from a car’s headlights scatters when shined into fog. This fog began about 400 million years after the big bang and lasted for 500 million years.

WMAP image of background cosmic radiation

Cosmic Microwave Background Radiation map


Lastly, WMAP data now places constraints on the inflation scenarios of the early expansion of the universe, with some scenarios eliminated altogether.

Results of this WMAP data were issued in seven papers submitted to the Astrophysical Journal.

See this link for the actual NASA news release: http://www.nasa.gov/home/hqnews/2008/mar/HQ_08076_WMAP_release.html

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