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Clocking an Accelerating Universe: First Results from BOSS

By Guest PostApril 4, 2012Scienceaccelerate, adam riess, apache point observatory, bao, baryon acoustic oscillation, berkeley lab, beth reid, big bang, brian schmidt, cmb, cosmic microwave background, dan long, dark energy, david schlegel, density peak, einstein, eric huff, euclidean universe, Galaxy, george smoot, gravitational attraction, gravity, high z supernova, hubble, martin white, megaparsecs, Milky Way, new mexico, nobel prize, phenomenon, redshifts, saul perlmutter, scp, sdss, sloan telescope, spectrograph, statistical analysis, universe, zosia rostomian

Berkeley Lab scientists are the leaders of BOSS, the Baryon Oscillation Spectroscopic Survey. They and their colleagues in the third Sloan Digital Sky Survey have announced the most precise measurements ever made of the era when dark energy turned on.

Some six billion light years distant, almost halfway from now back to the big bang, the universe was undergoing an elemental change. Held back until then by the mutual gravitational attraction of all the matter it contained, the universe had been expanding ever more slowly. Then, as matter spread out and its density decreased, dark energy took over and expansion began to accelerate.

Today BOSS, the Baryon Oscillation Spectroscopic Survey, the largest component of the third Sloan Digital Sky Survey (SDSS-III), announced the most accurate measurement yet of the distance scale of the universe during the era when dark energy turned on. (more…)

Closest Type Ia Supernova in Decades Solves a Cosmic Mystery

By Guest PostDecember 21, 2011Sciencecosmic mystery, dark energy, expansion of universe, light curve, thermonuclear supernova

Early close-ups of a Type Ia supernova allow Berkeley Lab scientists and their colleagues to picture its progenitor and infer how it exploded

Type Ia supernovae (SN Ia’s) are the extraordinarily bright and remarkably similar “standard candles” astronomers use to measure cosmic growth, a technique that in 1998 led to the discovery of dark energy – and 13 years later to a Nobel Prize, “for the discovery of the accelerating expansion of the universe.” The light from thousands of SN Ia’s has been studied, but until now their physics – how they detonate and what the star systems that produce them actually look like before they explode – has been educated guesswork. (more…)

Physicists Set Strongest Limit on Mass of Dark Matter

By Guest PostNovember 30, 2011Sciencedark energy, dark matter, dark matter collisions, dark matter particle, detecting dark matter, expansion of universe, mass

Brown University physicists have set the strongest limit for the mass of dark matter, the mysterious particles believed to make up nearly a quarter of the universe. The researchers report in Physical Review Letters that dark matter must have a mass greater than 40 giga-electron volts. The distinction is important because it casts doubt on recent results from underground experiments that have reported detecting dark matter

PROVIDENCE, R.I. [Brown University] — If dark matter exists in the universe, scientists now have set the strongest limit to date on its mass. (more…)

Berkeley Lab’s Saul Perlmutter wins Nobel Prize in Physics

By Guest PostOctober 4, 2011Science2011 nobel prize in physics, accelerating expansion of the universe, adam riess, anisotropy of the cosmic microwave background radiation, astrophysicist, berkeley lab, brian schmidt, Chile, dark energy, department of energy, expansion of the universe, france, george smoot iii, gravity, high z supernova search team, international supernova cosmology project, Japan, knowledge, lawrence berkeley national laboratory, mysterious force, nature of dark energy, nobel prize, nobel prize in physics, paul alivisatos, saul perlmutter, spain, supernova cosmology project, supernovae, Sweden, swedish kroner, united kingdom, united states, university of california at berkeley

BERKELEY, CA — Saul Perlmutter, an astrophysicist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley, has won the 2011 Nobel Prize in Physics “for the discovery of the accelerating expansion of the universe through observations of distant supernovae.” Perlmutter heads the international Supernova Cosmology Project, which pioneered the methods used to discover the accelerating expansion of the universe, and he has been a leader in studies to determine the nature of dark energy.

Perlmutter shares the prize with Brian Schmidt and Adam Riess, leader of the High-z Supernova Search Team and first author of that team’s analysis, respectively, which led to their almost simultaneous announcement of accelerating expansion. (more…)

NASA Telescope Helps Confirm Nature of Dark Energy

By Guest PostMay 20, 2011Science3 d map, albert einstein, anglo australian telescope, australia, big bang, caltech, chris blake, christopher martin, constant force, cosmic time, dark energy, dark matter, galaxies, galaxy evolution explorer, gravitational attractions, gravity, how dark energy works, jon morse, melbourne, NASA, siding spring mountain, swinburne university of technology, universe

PASADENA, Calif. — A five-year survey of 200,000 galaxies, stretching back seven billion years in cosmic time, has led to one of the best independent confirmations that dark energy is driving our universe apart at accelerating speeds. The survey used data from NASA’s space-based Galaxy Evolution Explorer and the Anglo-Australian Telescope on Siding Spring Mountain in Australia.

The findings offer new support for the favored theory of how dark energy works — as a constant force, uniformly affecting the universe and propelling its runaway expansion. They contradict an alternate theory, where gravity, not dark energy, is the force pushing space apart. According to this alternate theory, with which the new survey results are not consistent, Albert Einstein’s concept of gravity is wrong, and gravity becomes repulsive instead of attractive when acting at great distances. (more…)

Measuring the Distant Universe in 3-D

By Guest PostMay 7, 2011Science3 d map, absorption, anže slosar, apache point observatory, bao, baryon acoustic oscillation, baryon oscillation, baryon oscillation spectroscopic survey, berkeley lab, bill carithers, BOSS, centers of galaxies, dark energy, david schlegel, james rich, lyman alpha forest, map intergalactic hydrogen gas, new mexico, of light years, precision tool, quasars, red galaxies, redshift, sdss, sloan digital sky survey, sloan telescope, spectrum, supermassive black holes, universe, wiggly structure

*Berkeley Lab-led BOSS proves it can do the job with quasars*

The biggest 3-D map of the distant universe ever made, using light from 14,000 quasars — supermassive black holes at the centers of galaxies many billions of light years away — has been constructed by scientists with the third Sloan Digital Sky Survey (SDSS-III).

The map is the first major result from the Baryon Oscillation Spectroscopic Survey (BOSS), SDSS-III’s largest survey, whose principal investigator is David Schlegel of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). The huge new map was presented at the April meeting of the American Physical Society in Anaheim, CA, by Anže Slosar of Brookhaven National Laboratory. (more…)

Search for Dark Matter Narrowed by New Data From XENON100

By Guest PostApril 16, 2011Sciencebackground radiation, bombarding earth, cosmological observations, dark energy, dark matter, Germany, gran sasso national laboratory, mysterious dark matter, Netherlands, particle physics, particles, universe, weakly interacting massive particles, wimps, xenon collaboration, xenon100 experiment

*Collaboration reveals results from 100-day experiment*

Today, scientists from the XENON collaboration announced the result from their search for the elusive component of our universe known as dark matter. After analyzing one hundred days of data taken with the XENON100 experiment, they see no evidence for the existence of Weakly Interacting Massive Particles (WIMPs), the leading candidates for the mysterious dark matter. The XENON100 experiment is operated deep underground at the Gran Sasso National Laboratory of the Italian National Institute for Physics (INFN). (more…)

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