Scientists use world's fastest supercomputer to model origins of the unseen universeOctober 27, 20091 of the largest-ever computer models explores dark matter and dark energy, 2 cosmic constituents that remain a mystery LOS ALAMOS, New Mexico - Understanding dark energy is the number one issue in explaining the universe, according to Salman Habib, of the Laboratory's Nuclear and Particle Physics, Astrophysics and Cosmology group. "Because the universe is expanding and at the same time accelerating, either there is a huge gap in our understanding of physics, or there is a strange new form of matter that dominates the universe - 'dark energy' - making up about 70 percent of it," said Habib. "In addition, there is five times more of an unknown 'dark matter' than there is ordinary matter in the universe, and we know it's there from many different observations, most spectacularly, we've seen it bend light in pictures from the Hubble Space Telescope, but its origin is also not understood." Even though it's looking at only a small segment of the "accessible" universe, Habib's "Roadrunner Universe" model requires a petascale computer because, like the universe, it's mind-bendingly large. The model's basic unit is a particle with a mass of approximately one billion suns (in order to sample galaxies with masses of about a trillion suns), and it includes 64 billion and more of those particles. The model is one of the largest simulations of the distribution of matter in the universe, and aims to look at galaxy-scale mass concentrations above and beyond quantities seen in state-of-the-art sky surveys. "We are trying to really understand how to more completely and more accurately describe the observable universe, so we can help in the design of future experiments and interpret observations from ongoing observations like the Sloan Digital Sky Survey-III. We are particularly interested in the Large Synoptic Survey Telescope (LSST) in Chile, in which LANL is an institutional member, and DOE and NASA's Joint Dark Energy Mission (JDEM)," said Habib. "To do the science in any sort of reasonable amount of time requires a petascale machine at the least." The Roadrunner Universe model relies on a hierarchical grid/particle algorithm that best matches the physical aspects of the simulation to the hybrid architecture of Roadrunner. Habib and his team wrote an entirely new computer code that aggressively exploits Roadrunner's hybrid architecture and makes full use of the PowerXCell 8i computational accelerators. They also created a dedicated analysis and visualization software framework to handle the huge simulation database. "Our effort is aimed at pushing the current state of the art by three orders of magnitude in terms of computational and scientific throughput," said Habib. I'm confident the final database created by Roadrunner will be an essential component of dark universe science for years to come." DOE/Los Alamos National Laboratory |
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| Related Supercomputer Current Events and Supercomputer News Articles Getting a grip on school timetables A new approach to solving the problem of school timetabling, known as a GRASP, has been developing by researchers in Brazil. They report details in a forthcoming issue of the International Journal of Operational Research. A Superbright Supernova That's the First of Its Kind An extraordinarily bright, extraordinarily long-lasting supernova named SN 2007bi, snagged in a search by a robotic telescope, turns out to be the first example of the kind of stars that first populated the Universe. More than powerful! German research computer QPACE is the most energy efficient in the world At the 2009 Supercomputing Conference in Portland, Oregon (USA), the high-performance computer QPACE (QCD Parallel Computing on the Cell) was recognized today as the most energy-efficient supercomputer in the world. LANL Roadrunner models nonlinear physics of high-power lasers For years scientists have struggled with the difficult physics of inertial confinement fusion. This is the attempt to compress a target capsule containing isotopes of hydrogen with high-powered lasers to high enough pressure and temperature to initiate fusion burn. Scientists use world's fastest supercomputer to create the largest HIV evolutionary tree Supporting Los Alamos National Laboratory's role in the international Center for HIV/AIDS Vaccine Immunology (CHAVI) consortium, researchers are using the Roadrunner supercomputer to analyze vast quantities of genetic sequences from HIV infected people in the hope of zeroing in on possible vaccine target areas. Science at the Petascale: Roadrunner Results Unveiled The world's fastest supercomputer, Roadrunner, at Los Alamos National Laboratory has completed its initial "shakedown" phase doing accelerated petascale computer modeling and simulations of a variety of unclassified, fundamental science projects. Key new ingredient in climate model refines global predictions For the first time, climate scientists from across the country have successfully incorporated the nitrogen cycle into global simulations for climate change, questioning previous assumptions regarding carbon feedback and potentially helping to refine model forecasts about global warming. Kraken becomes first academic machine to achieve petaflop The National Institute for Computational Sciences' (NICS's) Cray XT5 supercomputer-Kraken-has been upgraded to become the first academic system to surpass a thousand trillion calculations a second, or one petaflop, a landmark achievement that will greatly accelerate science and place Kraken among the top five computers in the world. Research Team Finds First Evolutionary Branching for Bilateral Animals In the most computationally intensive phylogenetic analysis to date, an international research team led by Brown University has found the first evolutionary branching for bilateral animals. Berkeley Lab Scientists' Computer Code Gives Astrophysicists First Full Simulation of Star's Final Hours The precise conditions inside a white dwarf star in the hours leading up to its explosive end as a Type Ia supernova are one of the mysteries confronting astrophysicists studying these massive stellar explosions. More Supercomputer Current Events and Supercomputer News Articles |
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