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How Computers Push on the Molecules They Simulate

By Guest PostJanuary 9, 2013Scienceacceleration, albert einstein, algorithm, analytical results, artifacts, atoms and molecules, behavior, Berkeley, berkeley lab, calculation, california, california institute, chemical fuel, collide, computer method, conserve energy, david sivak, digital representation, digitize time, dna repair, driving force, effective friction, energy dense, equation, error, finite time steps, fluid, french physicist, gavin crooks, john chodera, langevin dynamics, model brownian motion, modeling molecular system, modern computer, molecular machines, molecular scale motion, molecule, momentum, natural system, nonequilibrium driving force, nonequilibrium statistical mechanics, particle, passage of time, paul langevin, photosynthesis, pollen grain, qb3, quantitative biosciences, quantum mechanics, real world, simulation, source, tenacious errors, theoretical method, thermal energy, toy models, university, velocity, water, water molecules

Berkeley Lab bioscientists and their colleagues decipher a far-reaching problem in computer simulations

Because modern computers have to depict the real world with digital representations of numbers instead of physical analogues, to simulate the continuous passage of time they have to digitize time into small slices. This kind of simulation is essential in disciplines from medical and biological research, to new materials, to fundamental considerations of quantum mechanics, and the fact that it inevitably introduces errors is an ongoing problem for scientists.

Scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have now identified and characterized the source of tenacious errors and come up with a way to separate the realistic aspects of a simulation from the artifacts of the computer method. The research was done by David Sivak and his advisor Gavin Crooks in Berkeley Lab’s Physical Biosciences Division and John Chodera, a colleague at the California Institute of Quantitative Biosciences (QB3) at the University of California at Berkeley. The three report their results in Physical Review X. (more…)

BOSS Quasars Unveil a New Era in the Expansion History of the Universe

By Guest PostNovember 21, 2012Scienceacceleration, analytic techniques, ancient universe, andreu font ribera, apache point observatory, bao, baryon, baryon acoustic oscillations, berkeley lab, bigboss, bill carithers, BOSS, clouds, cosmology, dark energy, dark matter, data sets, david schlegel, deceleration, density variation, digital sky survey, early universe, evolution, expanse of sky, expansion, gas clouds, gas density, gravity, hydrogen absorption lines, intergalactic gas, lyman alpha forest, mocks, new mexico, nicholas ross, oscillation, patrick mcdonald, quasars, riemann linux cluster, sdss, sloan, Space, spectra, spectroscopic, survey, universe, volume

Berkeley Lab scientists and their Sloan Digital Sky Survey colleagues use quasars to probe dark energy over 10 billion years in the past

BOSS, the Baryon Oscillation Spectroscopic Survey, is mapping a huge volume of space to measure the role of dark energy in the evolution of the universe. BOSS is the largest program of the third Sloan Digital Sky Survey (SDSS-III) and has just announced the first major result of a new mapping technique, based on the spectra of over 48,000 quasars with redshifts up to 3.5, meaning that light left these active galaxies up to 11.5 billion years in the past.

“No technique for dark energy research has been able to probe this ancient era before, a time when matter was still dense enough for gravity to slow the expansion of the universe, and the influence of dark energy hadn’t yet been felt,” says BOSS principal investigator David Schlegel, an astrophysicist in the Physics Division of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “In our own time, expansion is accelerating because the universe is dominated by dark energy. How dark energy effected the transition from deceleration to acceleration is one of the most challenging questions in cosmology.” (more…)

Peak Risk About 16 Years Old for Teens Misusing Prescription Drugs

By Guest PostMay 11, 2012Healthacceleration, adolescents, college age years, data, james c anthony, jonathan troost, michigan state university, misusing, prescriber, prescription drugs, public health, teens

EAST LANSING, Mich. — The peak risk for misusing prescription pain relievers occurs in mid-adolescence, specifically about 16 years old and earlier than many experts thought, according to a new study by Michigan State University researchers.

The results, based on recent nationwide surveys of nearly 120,000 U.S. adolescents, suggest prevention programs may need to be introduced earlier, in childhood and early adolescence, said James C. Anthony of MSU’s Department of Epidemiology and Biostatistics. (more…)

Kinect in the Classroom: Scratching the Surface of Potential

By Guest PostMarch 6, 2012Education, Technologyacceleration, austin, brazil, cameron evans, cheryl arnett, classroom, department of labor, disneyland, games, guinness world records, imagination, India, jack chang, jebediah pavleas, kinect, kinect effect, magic kingdom, Microsoft, robin angotti, saudi arabia, skype, stem, sunset elementary school, sxswedu, taiwan, Technology, texas, university of washington bothell, velocity, xbox 360

*First graders are using Kinect for Xbox 360 to get to places like Disneyland (on a map, at least), and high school students are graphing mathematical equations with their bodies.*

CRAIG, Colo. – March 6, 2012 – First-grade teacher Cheryl Arnett spent much of last summer playing Kinect for Xbox 360 with her grandkids.

For fun, yes, but the 19-year veteran teacher at Sunset Elementary School in Craig, Colo., also had an agenda. A longtime lover of technology, Arnett was looking for ways to teach with Microsoft’s controller-free device. When she brought Kinect to her classroom at the start of this school year, the reaction from her enthralled students was “over the top,” she said. (more…)

Scientists Discover a New Tiger Shark Hunting Technique

By Guest PostJune 8, 2011Natureacceleration, carl meyer, cosmopolitan predators, depth, digital still cameras, hawaii institute of marine biology, high resolution accelerometers, himb, hunting behavior of tiger sharks, japanese national institute of polar research, prey, reef and pelagic fishes, swimming dynamics, swimming speed, temperature, three dimensional spaces, tiger sharks, unicornfish, university of florida, university of hawaii at manoa, university of tokyo, west coast of hawaii island, yo yo swimming patterns

In a joint research effort between the University of Hawaiʻi at Mānoa’s Hawai‘i Institute of Marine Biology (HIMB), University of Tokyo, the Japanese National Institute of Polar Research, and the University of Florida, scientists have shed new light on the hunting behavior of tiger sharks by studying their swimming dynamics off the west coast of Hawai‘i Island. (more…)

Spacecraft will Enable Scientists to Study Space Environment around Moon, Earth

By Guest PostNovember 2, 20102 commentsScienceacceleration, artemis, artemis spacecraft, aurora borealis, earth, electrodynamics, Environment, events, gravity, lunar environment, macroscale interactions, magnetic field, mission, moon environment, NASA, particle acceleration, reconnection, satellites, Space, spacecraft, substorms, sun-earth-moon, themis, time history, turbulence, vassilis angelopoulos

Two spacecraft are now beginning to study the moon’s environment as part of NASA’s ARTEMIS mission, whose principal investigator is Vassilis Angelopoulos, a UCLA professor of Earth and space sciences.

One of these satellites has been in the lunar environment since Aug. 25, and the second arrived Oct. 22, marking the start of the ARTEMIS mission to gather new scientific data in the sun-Earth-moon environment.

About the image: An artist’s rendering of the two ARTEMIS spacecraft in the lunar environment. Image credit: NASA/SVS (more…)

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