From: yee@atlas.arc.nasa.gov (Peter Yee)
Subject: Big Bang Theory passes toughest test [Release 93-5] (Forwarded)
Apparently-To: sci-space-news@ames.arc.nasa.gov
Followup-To: sci.space
Originator: yee@atlas.arc.nasa.gov
Reply-To: yee@atlas.arc.nasa.gov (Peter Yee)
Organization: NASA Ames Research Center, Moffett Field, CA
Date: Thu, 7 Jan 1993 23:09:53 GMT

Paula Cleggett-Haleim
Headquarters, Washington, D.C.                                 January 7, 1993
(Phone:  202/358-0883)                                                           10:30 A.M. EST

Randee Exler
Goddard Space Flight Center, Greenbelt, Md.
(Phone:  301/286-7277)


RELEASE:  93-5

BIG BANG THEORY PASSES TOUGHEST TEST


	The Big Bang Theory passed its toughest test yet with the latest
results reported from NASA's Cosmic Background Explorer (COBE) team at the
American Astronomical Society meeting in Phoenix, Ariz., today.

	Precise measurements made by COBE's FIRAS of the afterglow from the
Big Bang -- the primeval explosion that began the universe approximately 15
billion years ago -- show that 99.97 percent of the early radiant energy of the
universe was released within the first year after the Big Bang itself.

	"Radiant energy" is energy emitted in any form of light, from x-rays
and gamma rays to visible and infrared light or even radio waves.  COBE's Far
Infrared Absolute Spectrophotometer (FIRAS) was designed to receive the
microwave and infrared energy from the Big Bang.

	"The Big Bang theory comes out a winner," said COBE Project Scientist
and FIRAS Principal Investigator Dr. John C. Mather of NASA's Goddard Space
Flight Center, Greenbelt, Md.  "This is the ultimate in tracing one's cosmic
roots," Mather said.

	All theories that attempt to explain the origin of large scale
structure seen in the universe today now must conform to the constraints
imposed by these latest measurements.

	This includes theories that postulate large amounts of energy released
by such things as black holes, exploding supermassive stars or the decay of
unstable elementary particles.  In other words, there were not a lot of "little
bangs," as suggested by some theories.

	The Big Bang Theory predicts that the spectrum of relic radiation
should be that of a perfect "black body" unless there were major energy
releases more than a year after the explosion.  (A black body is a hypothetical
cosmic body that absorbs all radiation falling on it, but reflects none
what-so-ever.  A black body emits at the same temperature at every wavelength.)
These latest FIRAS results reveal that later energy releases did not occur.

	The COBE scientists now can say that the temperature of the afterglow
radiation is 2.726 degrees above absolute zero (273 degrees below zero on the
Celsius scale) with an uncertainty of only 0.01 degrees.

	Today's announcement is the result of analyzing data from the FIRAS
during its 10 months of observations.  Hundreds of millions of measurements
were combined to obtain these unprecedentedly pre
	"Making certain that all of the measurements were combined correctly
required exquisitely careful work and lengthy analysis by a large team of COBE
scientists," Mather reported.

	"We are seeing the cold glow still remaining from the initially very
hot Big Bang.  These results now limit the size of any 'after shocks' following
the Big Bang.  The closer we examine the Big Bang the simpler the picture
gets," said Mather.

	"It took us 18 years of careful effort to reach this point, but now we
can say that the Big Bang Theory has been tested against observations to a fine
degree of precision," explained Mather.

	"Experimental evidence of the Big Bang was first found by Edwin Hubble
in the 1920's.  He found that distant galaxies in ever direction are going away
from us with speeds proportional to their distance.  Therefore, gallaxies that
are farther away are going faster.  This is exactly the pattern that would
occur if the entire universe originated in a single explosion, now called the
Big Bang.

	Papers on these results and their implications soon will be submitted
to the Astrophysical Journal for publication.

	COBE, launched Nov. 18, 1989, is managed by NASA's Goddard Space
Flight Center, for NASA's Office of Space Science and Applications,
Astrophysics Division, Washington, D.C.
Newsgroups: sci.space.news