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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…)

Testing Einstein’s E=mc2 in Outer Space

By Guest PostJanuary 5, 2013Sciencealbert einstein, andrei lebed, atomic bomb, conceptual model, cornell university library, curvature, electron, energy, energy level, everything, explosion, galileo galilei, general relativity, gps navigation, gravitational field, gravitational mass, gravity, hydrogen atom, iconic equation, mass, motion, moving object, nucleus, object, paradigm in physics, principles in physics, proton, quantum mechanics, quantum objects, relativistic, Space, special relativity, speed of light, stockholm, theory, theory of gravitation, ua physicist, unifying theory, university of arizona

UA physicist Andrei Lebed has stirred the physics community with an intriguing idea yet to be tested experimentally: The world’s most iconic equation, Albert Einstein’s E=mc2, may be correct or not depending on where you are in space.

With the first explosions of atomic bombs, the world became witness to one of the most important and consequential principles in physics: Energy and mass, fundamentally speaking, are the same thing and can, in fact, be converted into each other.

This was first demonstrated by Albert Einstein’s Theory of Special Relativity and famously expressed in his iconic equation, E=mc2, where E stands for energy, m for mass and c for the speed of light (squared). (more…)

Good Vibrations

By Guest PostAugust 17, 2012Scienceabsolute zero, amplification, attometer scale, berkeley lab, cavity optomechanics, dan stamper kurn, daniel brooks, death star, eit, electromagnetically induced transparency, electron, fabry pferot, frequency, good vibrations, gravitational wave, light, mechanical motion, mechanical resonator, microfabricated atom chip, millennium falcon, motions of objects, nathan brahms, nonclassical light, optical cavity, optomechanical amplifier, optomechanical system, optomechanical systems, optomechanics, picowatts, ponderomotive force, quantum fluctuation, quantum mechanics, quantum optical device, quantum optical effects, radiation, science fiction, squeezing, star wars, sydney schreppler, Technology, thierry botter, thomas purdy, tractor beam, ultracold atoms, ultrasensitive force sensors

Berkeley Lab and UC Berkeley Researchers Record First Direct Observations of Quantum Effects in an Optomechanical System

A long-time staple of science fiction is the tractor beam, a technology in which light is used to move massive objects – recall the tractor beam in the movie Star Wars that captured the Millennium Falcon and pulled it into the Death Star. While tractor beams of this sort remain science fiction, beams of light today are being used to mechanically manipulate atoms or tiny glass beads, with rapid progress being made to control increasingly larger objects. Those who see major roles for optomechanical systems in a host of future technologies will take heart in the latest results from a first-of-its-kind experiment.

Scientists with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley, using a unique optical trapping system that provides ensembles of ultracold atoms, have recorded the first direct observations of distinctly quantum optical effects – amplification and squeezing – in an optomechanical system. Their findings point the way toward low-power quantum optical devices and enhanced detection of gravitational waves among other possibilities. (more…)

Breakthrough Scientific Discoveries No Longer Dominated By the Very Young, Study Finds

By Guest PostNovember 11, 2011Science20th century, benjamin jones, biographical analysis, bruce weinberg, jeff grabmeier, knowledge, medicine, nobel laureates, nobel prize, nobel prize winner, northwestern university, ohio state university, physicists, physics, quantum mechanics, scientists under the age of 40, significant breakthroughs in chemistry

COLUMBUS, Ohio – Scientists under the age of 40 used to make the majority of significant breakthroughs in chemistry, physics and medicine – but that is no longer the case, new research suggests.

A study of Nobel Laureates from 1901 to 2008 in these three fields examined the age at which scientists did their prize-winning work.

Results showed that before 1905, about two-thirds of winners in all three fields did their prize-winning work before age 40, and about 20 percent did it before age 30. (more…)

Tag Archives: quantum mechanics

How Computers Push on the Molecules They Simulate

Testing Einstein’s E=mc2 in Outer Space

Good Vibrations

Breakthrough Scientific Discoveries No Longer Dominated By the Very Young, Study Finds