%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 1) News - April 26, 2000 NSF PR 00-25 Media contacts: ÊAmber Jones, NSF Ê(703) 306-1070 Êaljones@nsf.gov ÊDolores Beasley, NASA Ê(202) 358-1753 Êdbeasley@hq.nasa.gov Program contact: ÊAndrew Lange, Caltech Ê(626) 395-6887 Êael@astro.caltech.edu Cosmologists Reveal First Detailed Images of Early Universe 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 37 kilometers (120,000 feet) 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 12-15 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 that is 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 (COBE) satellite discovered the first evidence for structures, or spatial variations, in the CMB in 1991. The BOOMERANG images are the first to bring the CMB into sharp focus. The images reveal hundreds of complex regions that are 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. "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 three percent of the sky. The team's analysis of the size of the structures in the CMB 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 that occurred 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 800,000 cubic meters (28 million cubic feet), carried the two-ton telescope 8,000 km (5,000 miles) in 10 1/2 days and landed within 50 km (31 miles) 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. -NSF- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 2) Images of Early Universe Revealed Updated 6:43 AM ET April 27, 2000 By MATTHEW FORDAHL, AP Science Writer PASADENA, Calif. (AP) - The first detailed images of the embryonic universe suggest the cosmos will expand forever and not someday collapse upon itself, according to new research on the Big Bang published today. Observations from a balloon-borne telescope that circumnavigated Antarctica largely match predictions and suggest scientists are on the right track in their understanding of the earliest moments of the universe, its composition and ultimate fate. "It is an incredible triumph of modern cosmology to have predicted their basic form so accurately," said Andrew Lange of the California Institute of Technology and U.S. team leader of the $4 million international project dubbed "Boomerang." The sensitive telescope carried aloft for nearly 11 days in late 1998 measured minute variations in the cosmic microwave background radiation, a faint glow that fills the sky in all directions and is believed to be the fading remnants of the Big Bang 12 billion to 15 billion years ago. The images reveal the large-scale geometry of the cosmos and the underlying structures that were the precursors of today's clusters of galaxies. "We are seeing something like the seeds of creation of the structure of the modern universe," said Harley Thronson, senior science manager for NASA's space science office. NASA, the National Science Foundation and the Department of Energy participated in the project along with four nations and 16 universities. In the first results, published in today's journal Nature, scientists said the ripple patterns precisely match the scenario of a "flat" universe in which parallel lines never cross. The findings rule out the possibility that the fabric of space-time is curved onto itself like a sphere or bent outward like a saddle. It also means that the universe will not collapse in a big crunch. "We are really demonstrating that it's flat, and we are demonstrating that it will expand forever," said Italian team leader Paolo deBernardis of the University of Rome, La Sapienza. The flat universe also fits the so-called inflationary theory that the universe underwent a rapid expansion in a fraction of a second after its birth. "It's confirmation of the prediction of our best theory of what caused the structure of the universe," said Alan Guth, a Massachusetts Institute of Technology physicist who first proposed the theory in 1980. "It means that there's a very good chance that we're on the right track." Measurements of the small ripples indicate the large-scale geometry of the universe, which the general theory of relativity says is determined by the total amount of matter and energy in the cosmos. The Boomerang data also reveal hundreds of complex structures that represent the effects of the density variations in the early universe. They are the seeds in which clusters of galaxies would form, said Boomerang scientist John Ruhl, a physicist at the University of California, Santa Barbara. Scientists hope to further refine the data to better quantify the nature of the matter that makes up the cosmos. "What we will get is a census of the universe but without knowing what kind of things make up the population," said Edward Wright, an astronomer at the University of California, Los Angeles. Shortly after the Big Bang, the universe was made of a fog of subatomic particles and radiation hotter than the surface of the sun. It was so dense that photons - the smallest units of energy - bounced off the primordial soup. As the universe expanded and cooled, normal matter formed and the photons no longer scattered but moved freely through space. Boomerang analyzes variations that echo the final scattering, roughly 300,000 years after the Big Bang. The background radiation, which contributes to snow on earthly television sets, was first detected in 1965. But the tiny ripples or variations were not found until 1991 by NASA's Cosmic Background Explorer satellite. The satellite covered the entire sky but had a very coarse view, far too rough for scientists to see enough detail to discern complex structures. The Boomerang experiment, by comparison, covered 2.5 percent of the sky but with a resolution 35 times higher. Scientists with the Boomerang project (it stands for Balloon Observations of Millimetric Extragalactic Radiation and Geophysics) plan another flight in search of even greater detail. Two satellites will be launched in coming years that will analyze the entire sky with high precision and detail. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%