By Deborah Zabarenko
WASHINGTON
(Reuters) - By tracking cosmic ``music'' and slamming particles
of gold together, scientists said on Monday they are closer to
finding out what happened just after the theoretical Big Bang
at the birth of the universe.
In the millionth
of a second following the primordial blast some 15 billion years
ago, physicists think the universe changed from an almost unimaginably
dense object the size of a baseball to a violently expanding mess
of subatomic particles.
The universe
continues to expand to this day, scientists believe, but much
more slowly.
To try to
replicate this early, messy time, scientists at the Brookhaven
National Laboratory (news - web sites) fired bits of gold -- actually
the nuclei of gold atoms, called gold ions -- at each other at
nearly the speed of light.
That speed
is nearly 186,000 miles per second.
They wanted
to duplicate what they believe happened in the instant after the
Big Bang, when the universe was composed of a roiling soup of
subatomic particles they call the quark-gluon plasma.
Quarks and
gluons are normally trapped inside protons and neutrons -- which
are parts of atoms -- but in the early universe they were free-floating,
according to John Cramer, a physicist at the University of Washington
who worked on the experiment.
When the gold
nuclei slammed together, ``They made a fireball and the fireball
emitted particles for a shorter time than we expected and the
explosion was more violent,'' Cramer said in an interview at the
American Physical Society's spring meeting in Washington.
The research
strongly suggests but does not prove that the quark-gluon plasma
exists, another piece in the puzzle of how the universe was formed.
Future experiments using the Relativistic Heavy Ion Collider (news
- web sites) at Brookhaven, the government's 5,265-acre site in
Suffolk County, New York, will investigate further, Cramer said.
'Music' In
Cosmic Microwaves
Further support
for the theory of massive expansion in the first moments of the
universe came from physicists who detected what they called the
``music of creation'' in waves that rippled through the cosmos
in its earliest instants.
These are
not sounds that can be heard but have been detected by sensitive
instruments that took readings from Antarctica, where the search
for cosmic microwaves is less muddied by the same kinds of microwaves
encountered routinely on Earth for communications transmission
and cooking.
These instruments
looked back in time to about 400,000 years after the Big Bang,
where they found minute variations in the cosmic microwave background
radiation left from the original explosion.
This finding
is in line with what cosmologists believe about the first instant
after the Big Bang, in which violent rapid expansion occurs in
a process known as inflation.
``Inflation
is the dynamite behind the Big Bang,'' Michael Turner, a cosmologist
at the University of Chicago, said in commenting on these findings.
``We're still questing for the match.''
Theorists
predicted that the size of the structures that formed in the early
universe would create a ``harmonic series'' of peaks that would
be branded on the cosmic microwave background.
Last year,
using data from a balloon-borne instrument called Boomerang that
circled over Antarctica in 1998, scientists detected one ``note''
in this harmonic series.
This was a
strong indicator that the cosmic microwave background bore the
imprint of inflation, but new analyzes of data from Boomerang
and another Antarctic instrument known as DASI offer evidence
of ``overtones'' -- two more peaks in the series -- that give
more weight to the inflation theory.
These analyzes
of Boomerang and DASI research were presented on Sunday at the
physicists' meeting.
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