Science News
Scientists Find "Fingerprint" of Human Activities in Recent Tropopause Height Changes
A team of scientists, including Michael Wehner of LBNL's Computational Research Division, has determined that human-induced changes in ozone and well-mixed greenhouse gases are the primary drivers of recent changes in the height of the tropopause. The team is led by Ben Santer of LLNL and their work is described in a paper entitled, "Contributions of Anthropogenic and Natural Forcing to Recent Tropopause Height Changes," which appears in the July 25, 2003 edition of Science. Read More »
Simulation Computed at NERSC Matches Historic Gamma-Ray Burst
After three decades of scientific head-scratching, the origins of at least some gamma-ray bursts (GRBs) are being revealed, thanks to a new generation of orbiting detectors, fast responses from ground-based robotic telescopes, and a new generation of computers and astrophysics software. Read More »
New Computational and Scientific Results at NERSC: Science-of-Scale Applications Achieve Significant Results and up to 68% of Peak Performance on 10 Tflop/s IBM SP (3-10-03)
Initial results from NERSC’s 10 teraflop/s IBM SP supercomputer, which became available for general use in early March 2003, show scientific applications running at up to 68% of the system’s theoretical peak speed, compared with the 5–10% of peak performance typical for scientific applications running on massively parallel or cluster architectures. Read More »
NERSC Helps Get the Physics out of KamLAND Data
The Standard Model of Particle Physics, which has successfully explained fundamental physics since the 1970s, predicts that neutrinos have no mass and come in three types or "flavors," electron, muon, and tau. But for the past four years, solar neutrino experiments at the Super-Kamiokande Observatory (Super-K) in Japan and the Sudbury Neutrino Observatory (SNO) in Canada have offered compelling evidence that neutrinos do have nonzero mass and oscillate between the three flavors Read More »
NERSC Helps Climate Scientists Complete First Ever 1,000-Year Run of Nation's Leading Climate Change Modeling Application
Scientists from the National Center for Atmospheric Research (NCAR) have just completed a 1,000-year run of a powerful new climate system model on a supercomputer at the U.S. Department of Energy's National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. Accurately predicting global climate change demands complex and comprehensive computer simulation codes, the fastest supercomputers available and the ability to run those simulations long enough to model century after century of the global climate. Read More »
Are the Digits of Pi Random?
David H. Bailey, chief technologist of the Department of Energy's National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory, and his colleague Richard Crandall, director of the Center for Advanced Computation at Reed College, Portland, Oregon, have taken a major step toward answering the age-old question of whether the digits of pi and other math constants are "random." Their results are reported in the Summer 2001 issue of Experimental Mathematics. Read More »
A Lucky Catch: The Oldest, Most Distant Type Ia Supernova Confirmed by Supercomputer Analysis at NERSC
An exploding star dubbed SN 1997ff, caught once on purpose and twice by accident by NASA's Hubble Space Telescope, is the oldest and most distant Type Ia supernova ever seen, according to a recent analysis by the Department of Energy's National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. Read More »
BOOMERANG Antarctic Balloon Flight Sees a Flat Universe
On April 26, 2000, the international BOOMERANG consortium led by Andrew Lange of the California Institute of Technology and Paolo de Bernardis of Università de Roma, "La Sapienza," announced results of the most detailed measurement yet made of the cosmic microwave background radiation (CMB). Read More »
An Algorithm for the Ages
Among the top 10 "Algorithms of the Century" announced in the January/February, 2000, issue of Computing in Science and Engineering magazine is the integer-relation algorithm dubbed PSLQ, discovered by mathematician and sculptor Helaman Ferguson of Maryland's Center for Computing Sciences, and implemented in practical computer software by David Bailey, chief technologist of the National Energy Research Scientific Computing Center (NERSC) at the Department of Energy's Lawrence Berkeley National… Read More »
Solved at Last: A Fundamental Problem of Quantum Physics
For over half a century, theorists have tried and failed to provide a complete solution to scattering in a quantum system of three charged particles, one of the most fundamental phenomena in atomic physics. Such interactions are everywhere; ionization by electron impact, for example, is responsible for the glow of fluorescent lights and for the ion beams that engrave silicon chips. Read More »
BOOMERanG Analysis Finds Flat Universe
Newly released data from the 1997 North American test flight of BOOMERanG, which mapped anisotropies in the cosmic microwave background radiation (CMB) in a narrow strip of sky, show a pronounced peak in the CMB "power spectrum" at an angular scale of about one degree, strong evidence that the universe is flat. Analyzed at the Department of Energy's National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory, the new… Read More »
New Biological Database Seeks Out Products of Alternative Gene Splicing
In its first half year of operation, a new database that identifies clusters of proteins arising from alternative gene splicing has received more than 35,000 requests from researchers in genetics and cell and developmental biology around the world. Read More »
NERSC and the Fate of the Universe
When the National Energy Research Scientific Computing Center (NERSC) moved to Berkeley Lab in 1996, a computational science program was created to encourage collaborations between physical and computer scientists. The Supernova Cosmology Project's work was one of the first projects funded; it demonstrates how high-performance computing can accelerate scientific discovery. Read More »
A Flaw in the Law
Turbulence is a primal force that can be seen all around us, from the scudding of clouds to the frothing of the sea, from the wrinkling of flames to the swirling of leaves. It is especially important to the study of aerodynamics, in which correctly calculating the effects of turbulence can determine whether or not an airplane remains aloft. Since 1938, the standard equation presented in aerodynamics and engineering textbooks for calculating the forces exerted on a solid object by turbulence has… Read More »
Powerful Computers Advance Fusion Research at the Princeton Plasma Physics Laboratory
Scientists at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) report a major advance in the computer modeling of fusion plasmas in the September 18 edition of Science magazine. The new results were obtained utilizing the massively parallel processing (MPP) capabilities of the DOE's National Energy Research Scientific Computing Center (NERSC) at the Lawrence Berkeley National Laboratory in Berkeley, California. Read More »
Did the Big Bang Come With Strings Attached?
The power of supercomputers at the National Energy Research Scientific Computing Center (NERSC) has enabled Julian Borrill of the Department of Energy’s Lawrence Berkeley National Laboratory to model, in striking detail, a possible state of the universe only a hundred billionth of a trillionth of a trillionth of a second after the Big Bang. Read More »
Quantum Dot Simulations From T3E Make Journal Cover
Results of million-atom Quantum Dot simulations performed on the Cray T3E at NERSC by Alex Zunger's group at the National Renewable Energy Laboratory in Golden, Colo., will appear on the cover of the February issue of the Materials Research Society Bulletin. Read More »
Berkeley Researchers Eliminate One Theory in Mystery of Missing Xenon, but Find New Clues About Element's Behavior
Scientists at Ernest Orlando Lawrence Berkeley National Laboratory and the University of California, Berkeley, looking into the "mystery of the missing xenon" have found strong evidence against one leading theory and, along the way, discovered new information about the behavior of the element. Read More »
Protein Dynamics and Biocatalysis
Investigators: P. A. Bash, Northwestern University Medical School and M. Karplus, Harvard University Research Objectives A guiding principle of molecular biology is that the structure of a biomolecule defines its function. This principle is especially true in the case of the protein molecules known as enzymes, which serve as highly specific and extraordinarily efficient catalysts of biochemical reactions. Despite the growing availability of the atomic structures of enzymes, details of the… Read More »
Theoretical Study on Catalysis by Protein Enzymes and Ribozyme
Principal Investigator: Martin Karplus, Harvard University Research Objectives The goal of this project is to develop a greater understanding of the mechanisms involved in enzyme catalysis and related protein functions. We are studying two types of enzymes: proteins and a nucleic acid (hammerhead ribozyme). Computational Approach For active-site models in the gas phase, ab initio or density functional (DFT) calculations are used. A few calculations with continuum dieletric models are… Read More »
QM/MM Studies of the Triosephosphate Isomerase-Catalyzed Reaction
Triosephosphate isomerase (TIM) is a dimeric enzyme that catalyzes the conversion between dihydroxyacetone phosphate (DHAP) and R-glyceraldehyde 3-phosphate (GAP), which is an important step in glycolysis (the enzymatic breakdown of carbohydrates). TIM increases the reaction rate by more than109 times, and has thus been referred to as a “perfect” enzyme. Many experimental techniques have been used to study the enzyme, supplemented by a number of theoretical calculations, but the complex… Read More »
Theoretical Study on Catalysis by Protein Enzymes, Ribosome, and Molecular Motors
Principal Investigator: Martin Karplus, Harvard University Research Objectives This project's goal is to develop a greater understanding of the mechanisms involved in enzyme catalysis and related protein functions. We are studying the protein enzymes chorismate mutase, flavoxireductase, and aminopeptidase, and a nucleic acid enzyme, the hammerhead ribosome. We are also studying another class of enzymes known as molecular motors, which play important roles in bioenergy transduction and gene… Read More »
