Cosmologists Reveal First Detailed Images of Early Universe
Dolores Beasley
Headquarters, Washington, DC
April 26, 2000
(Phone: 202/358-1753)
Amber Jones
National Science Foundation, Arlington, VA
(Phone: 703/306-1070)
RELEASE: 00-67
An international team of cosmologists has released the
first detailed images of the universe in its infancy. The
images reveal the structure that existed in the universe
when it was a tiny fraction of its current age and 1,000
times smaller and hotter than it is today. Detailed
analysis of the images is already shedding light on some of
cosmology’s outstanding mysteries — the nature of the
matter and energy that dominate intergalactic space and
whether space is “curved” or “flat.”
The project, dubbed BOOMERANG (Balloon Observations of
Millimetric Extragalactic Radiation and Geophysics),
obtained the images using an extremely sensitive telescope
suspended from a balloon that circumnavigated the Antarctic
in late 1998. The balloon carried the telescope at an
altitude of almost 120,000 feet (37 kilometers) for 10 1/2
days. The results will be published in the April 27 issue
of Nature.
Today, the universe is filled with galaxies and
clusters of galaxies. But 12 to 15 billion years ago,
following the Big Bang, the universe was very smooth,
incredibly hot and dense. The intense heat that filled the
embryonic universe is still detectable today as a faint
glow of microwave radiation visible in all directions. This
radiation is known as the cosmic microwave background
(CMB). Since the CMB was first discovered by a ground-based
radio telescope in 1965, scientists have eagerly sought to
obtain high-resolution images of this radiation. NASA’s
Cosmic Background Explorer satellite discovered the first
evidence for structures, or spatial variations, in the
microwave background in 1991.
The BOOMERANG images are the first to bring the cosmic
microwave background into sharp focus. The images reveal
hundreds of complex regions visible as tiny variations —
typically only 100-millionths of a degree Celsius (0.0001
C) — in the temperature of the CMB. The complex patterns
visible in the images confirm predictions of the patterns
that would result from sound waves racing through the early
universe, creating the structures that by now have evolved
into giant clusters and super-clusters of galaxies.
“The structures in these images predate the first star
or galaxy in the universe,” said U.S. team leader Andrew
Lange of the California Institute of Technology, Pasadena.
“It is an incredible triumph of modern cosmology to have
predicted their basic form so accurately.”
Italian team leader Paolo deBernardis of the
University of Rome La Sapienza added: “It is really
exciting to be able to see some of the fundamental
structures of the universe in their embryonic state. The
light we have detected from them has traveled across the
entire universe before reaching us, and we are perfectly
able to distinguish it from the light generated in our own
galaxy.”
The BOOMERANG images cover about 3 percent of the sky.
The team’s analysis of the size of the structures in the
cosmic microwave background has produced the most precise
measurements to date of the geometry of space-time, which
strongly indicate that the geometry of the universe is
flat, not curved. This result is in agreement with a
fundamental prediction of the “inflationary” theory of the
universe. This theory hypothesizes that the entire universe
grew from a tiny subatomic region during a period of
violent expansion occurring a split second after the Big
Bang. The enormous expansion would have stretched the
geometry of space until it was flat.
NASA’s National Scientific Balloon Facility was
instrumental in flying the giant helium balloon that
carried the instruments above the earth’s atmosphere. The
National Science Foundation (NSF), which provides logistic
support for all U.S. scientific operations in Antarctica,
facilitated the launch near McMurdo Station and recovery of
the payload after the flight. The constant sunshine and
prevailing winds at high altitudes in Antarctica were
essential to maintaining a stable long-duration balloon
flight for the BOOMERANG project. The balloon, with a
volume of 28 million cubic feet (800,000 cubic meters),
carried the two-ton telescope 5,000 miles (8,000 km) and
landed within 31 miles (50 km) of its launch site.
The 36 team members are from 16 universities and
organizations in Canada, Italy, the United Kingdom and the
United States. Primary support for the BOOMERANG project
comes from NSF and NASA in the United States; the Italian
Space Agency, Italian Antarctic Research Programme and the
University of Rome La Sapienza in Italy; and the Particle
Physics and Astronomy Research Council in the United
Kingdom. The Department of Energy’s National Energy
Research Scientific Computing Center provided
supercomputing support in the United States.
More information on and images of BOOMERANG can be found
at:
http://www.physics.ucsb.edu/~boomerang/
More information on the NASA Scientific Balloon Program can
be found at:
http://www.wff.nasa.gov/pages/scientificballoons.html
