Fwd: WMAP Reveals Neutrinos, End of Dark Ages, First Second of Universe

[Henk Elegeert]

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---------- Forwarded message ----------
From: NASA News <hqnews at mediaservices.nasa.gov>
Date: Fri 07 Mar 2008 17:00:01 EST
Subject: WMAP Reveals Neutrinos, End of Dark Ages, First Second of Universe
To: NASA News <hqnews at mediaservices.nasa.gov>


March 7, 2008

 J.D. Harrington
 Headquarters, Washington
 202-358-5241
 j.d.harrington at nasa.gov

 Robert Naeye/Rob Gutro
 Goddard Space Flight Center, Greenbelt, Md.
 301-286-4453/4044

 Lisa De Nike
 Johns Hopkins University, Baltimore, Md.
 443-287-9960
 Lde at jhu.edu

 Kitta MacPherson
 Princeton University, Princeton, N.J.
 609-258-5729
 kittamac at princeton.edu

 Rebecca Johnson
 University of Texas at Austin McDonald Observatory
 512-475-6763
 rjohnson at astro.as.utexas.edu

 RELEASE: 08-079

 WMAP REVEALS NEUTRINOS, END OF DARK AGES, FIRST SECOND OF UNIVERSE

 WASHINGTON - NASA released this week five years of data collected by
 the Wilkinson Microwave Anisotropy Probe (WMAP) that refines our
 understanding of the universe and its development. It is a treasure
 trove of information, including at least three major findings:


 New evidence that a sea of cosmic neutrinos permeates the universe
 Clear evidence the first stars took more than a half-billion years to
 create a cosmic fog
 Tight new constraints on the burst of expansion in the universe's
 first trillionth of a second

 "We are living in an extraordinary time," said Gary Hinshaw of NASA's
 Goddard Space Flight Center in Greenbelt, Md. "Ours is the first
 generation in human history to make such detailed and far-reaching
 measurements of our universe."

 WMAP measures a remnant of the early universe - its oldest light. The
 conditions of the early times are imprinted on this light. It is the
 result of what happened earlier, and a backlight for the later
 development of the universe. This light lost energy as the universe
 expanded over 13.7 billion years, so WMAP now sees the light as
 microwaves. By making accurate measurements of microwave patterns,
 WMAP has answered many longstanding questions about the universe's
 age, composition and development.

 The universe is awash in a sea of cosmic neutrinos. These almost
 weightless sub-atomic particles zip around at nearly the speed of
 light. Millions of cosmic neutrinos pass through you every second.

 "A block of lead the size of our entire solar system wouldn't even
 come close to stopping a cosmic neutrino," said science team member
 Eiichiro Komatsu of the University of Texas at Austin.

 WMAP has found evidence for this so-called "cosmic neutrino
 background" from the early universe. Neutrinos made up a much larger
 part of the early universe than they do today.

 Microwave light seen by WMAP from when the universe was only 380,000
 years old, shows that, at the time, neutrinos made up 10% of the
 universe, atoms 12%, dark matter 63%, photons 15%, and dark energy
 was negligible. In contrast, estimates from WMAP data show the
 current universe consists of 4.6% percent atoms, 23% dark matter, 72%
 dark energy and less than 1 percent neutrinos.

 Cosmic neutrinos existed in such huge numbers they affected the
 universe's early development. That, in turn, influenced the
 microwaves that WMAP observes. WMAP data suggest, with greater than
 99.5% confidence, the existence of the cosmic neutrino background -
 the first time this evidence has been gleaned from the cosmic
 microwaves.

 Much of what WMAP reveals about the universe is because of the
 patterns in its sky maps. The patterns arise from sound waves in the
 early universe. As with the sound from a plucked guitar string, there
 is a primary note and a series of harmonics, or overtones. The third
 overtone, now clearly captured by WMAP, helps to provide the evidence
 for the neutrinos.

 The hot and dense young universe was a nuclear reactor that produced
 helium. Theories based on the amount of helium seen today predict a
 sea of neutrinos should have been present when helium was made. The
 new WMAP data agree with that prediction, along with precise
 measurements of neutrino properties made by Earth-bound particle
 colliders.

 Another breakthrough derived from WMAP data is clear evidence the
 first stars took more than a half-billion years to create a cosmic
 fog. The data provide crucial new insights into the end of the "dark
 ages," when the first generation of stars began to shine. The glow
 from these stars created a thin fog of electrons in the surrounding
 gas that scatters microwaves, in much the same way fog scatters the
 beams from a car's headlights.

 "We now have evidence that the creation of this fog was a drawn-out
 process, starting when the universe was about 400 million years old
 and lasting for half a billion years," said WMAP team member Joanna
 Dunkley of the University of Oxford in the U.K. and Princeton
 University in Princeton, N.J. "These measurements are currently
 possible only with WMAP."

 A third major finding arising from the new WMAP data places tight
 constraints on the astonishing burst of growth in the first
 trillionth of a second of the universe, called "inflation", when
 ripples in the very fabric of space may have been created. Some
 versions of the inflation theory now are eliminated. Others have
 picked up new support.

 "The new WMAP data rule out many mainstream ideas that seek to
 describe the growth burst in the early universe," said WMAP principal
 investigator, Charles Bennett, of The Johns Hopkins University in
 Baltimore, Md. "It is astonishing that bold predictions of events in
 the first moments of the universe now can be confronted with solid
 measurements."

 The five-year WMAP data were released this week, and results were
 issued in a set of seven scientific papers submitted to the
 Astrophysical Journal. For further information, see

 http://wmap.gsfc.nasa.gov

 Prior to the release of the new five-year data, WMAP already had made
 a pair of landmark finds. In 2003, the probe's determination that
 there is a large percentage of dark energy in the universe erased
 remaining doubts about dark energy's very existence. That same year,
 WMAP also pinpointed the 13.7 billion year age of the universe.

 Additional WMAP science team institutions are: the Canadian Institute
 for Theoretical Astrophysics, Columbia University, University of
 British Columbia, ADNET Systems, University of Chicago, Brown
 University, and UCLA.

 For related images to this story, please visit on the Web:

 http://www.nasa.gov/topics/universe/features/wmap_five.html


 -end-

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