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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…)

Joint Palestinian-American Dig Near Jericho Yields Clues About Early Islamic Culture

By Guest PostOctober 26, 2011Cultureamericans and palestinians, archaeologists, artifacts, bananas and lush vegetation, Bible, byzantine empire, caliph, christian and islamic communities, citrus fruits, city, culture, donald whitcomb, early islamic site, forbidden in islam, gil stein, hamdan taha, hisham palace, iconic site, ipads, islam, islamic civilization, jericho, joint palestinian american project, joshua, khirbet al mafjar, mafjar project, michael jennings, middle east, nephew, north of jericho, palestinian, palestinian director of antiquities, qasr hisham, rome, rule of caliph hisham, spatial relationship, sub tropical environment of palms, Technology, the tree of life, walid

As the Byzantine Empire was in decline, Islam began to dominate the Middle East, with a remarkable culture that showed a command of technology and an appreciation of art and decoration, research by archaeologists shows.

In order to study Islamic civilization in its earliest days, Donald Whitcomb, who directs the Islamic Archaeology project at the Oriental Institute, is undertaking a project with Palestinian colleagues to further excavate an early Islamic site north of Jericho that contains a palace, a bathhouse and what was probably a settlement to the north. (more…)

For UCLA Expert on Chumash Indians, Roughly Hewn Beads are Child’s Play

By Guest PostMay 8, 2011Culture, Scienceamerican southwest pueblos, archaeologist, archaeology, artifacts, bead makers, beads, california, channel islands, chumash, chumash indians, chumash people, craft apprenticeship, europeans, france, global archaeological record, jeanne arnold, North America, olivella, olivella biplicata shells, Paris, santa cruz island, shells, southern california, stone age, ucla

As the world’s leading authority on beads manufactured from shells by California’s Chumash Indians, UCLA archaeologist Jeanne Arnold was stumped by a series of anomalous artifacts excavated at former settlements on the Channel Islands.

Pierced with more than one hole, often at unconventional angles or too close to the edges, the oddly configured multi-hole beads differ considerably from the smooth, round, precisely drilled beauties that served as currency among the Chumash prior to the arrival of Europeans in Southern California. (more…)

Tag Archives: artifacts

How Computers Push on the Molecules They Simulate

Joint Palestinian-American Dig Near Jericho Yields Clues About Early Islamic Culture

For UCLA Expert on Chumash Indians, Roughly Hewn Beads are Child’s Play