Tag Archives: electron

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…)

Flexing Fingers for Micro-Robotics: Berkeley Lab Scientists Create a Powerful, Microscale Actuator

By Guest PostDecember 18, 2012Scienceartificial muscles, beckoning finger, berkeley lab, chromium metal layer, chun cheng, electron, electronic behaviors, flex, human muscle cells, junqiao wu, kai liu, kevin wang, metal, microactuator, microfluidics, micron, microscale actuator, natural application, oxide material, phase transitions, phenomena, phillip m. duxbury, piezoelectric device, piezoelectric technology, ramamoorthy ramesh, subhendra d mahanti, Technology, temperature variation, university of california, vanadium dioxide, zhenting cheng

Berkeley, Calif., Dec. 2012 — Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley, have developed an elegant and powerful new microscale actuator that can flex like a tiny beckoning finger. Based on an oxide material that expands and contracts dramatically in response to a small temperature variation, the actuators are smaller than the width of a human hair and are promising for microfluidics, drug delivery, and artificial muscles.

“We believe our microactuator is more efficient and powerful than any current microscale actuation technology, including human muscle cells,” says Berkeley Lab and UC Berkeley scientist Junqiao Wu. “What’s more, it uses this very interesting material—vanadium dioxide—and tells us more about the fundamental materials science of phase transitions.” (more…)

Measuring Table-Top Accelerators’ State-of-the-Art Beams

By Guest PostNovember 4, 2012Scienceaccelerator, berkeley lab, boundary, chen lin, coherent, cotr, density modulation, electron, electron beam, electron laser, fusion research, high density, high energy, hydrogen gas, initial momentum, jeroen van tilborg, laser plasma acceleration, light regime, light source, loasis, longitudinal slice, lpa, modulation, momentum, mylar foil, optical, particle count, photon pattern, plasma, pulse, radiation, transition, ultrathin, vacuum, wim leemans, xray window

Studies by Berkeley Lab scientists of electron beam quality in laser plasma accelerators include novel tests for slice-energy spread

Part Two: Slicing through the electron beam

Wim Leemans of Berkeley Lab’s Accelerator and Fusion Research Division heads LOASIS, the Laser and Optical Accelerator Systems Integrated Studies, an oasis indeed for students pursuing graduate studies in laser plasma acceleration (LPA). Among the most promising applications of future table-top accelerators are new kinds of light sources, in which their electron beams power free electron lasers.

“If our LPA electron bunches had good enough quality for free electron lasers – and were really only femtoseconds long – we should see a particular kind of radiation called coherent optical transition radiation, or COTR,” Leemans says. “So I assigned my doctoral student Chen Lin, a graduate of Peking University and now a postdoc there, to find it.” (more…)

How Silver Turns People Blue

By Guest PostOctober 27, 2012Scienceabsorb, acidic environment, agnes kane, antimicrobial, argyria, base membrane, bioavailable salt, bloodstream, brown researcher, brown university, charged ions, disorder, electron, environmental impact, exposure scenario, frances liu, germs, gi tract, grayish blue, health tonics, jingyu liu, medical treatment, nanoparticle, particle, photochemical reaction, protein, robert hurt, salt ion, silver, silver atom, silver salt, skin, toxic, toxicity, zhongying wang

Ingesting silver — in antimicrobial health tonics or for extensive medical treatments involving silver — can cause argyria, condition in which the skin turns grayish-blue. Brown researchers have discovered how that happens. The process is similar to developing black-and-white photographs, and it’s not just the silver.

PROVIDENCE, R.I. [Brown University] — Researchers from Brown University have shown for the first time how ingesting too much silver can cause argyria, a rare condition in which patients’ skin turns a striking shade of grayish blue.

“It’s the first conceptual model giving the whole picture of how one develops this condition,” said Robert Hurt, professor of engineering at Brown and part of the research team. “What’s interesting here is that the particles someone ingests aren’t the particles that ultimately cause the disorder.” (more…)

Another Advance on the Road to Spintronics

By Guest PostOctober 21, 2012Sciencealbert einstein, alexander gray, analyzer, basis, berkeley lab, charles fadley, computing industry, contamination, data, dilute, electron, electronic structure, energy conversion, energy-efficient, exchange model, facility, ferromagnetic, gallium arsenide, gallium atom, gamnas, harpes, hyogo, jan minar, Japan, jun fujii, kelvin, magnetic atom, magnetic semiconductor, memory architecture, nanoscale device, new technique, p d, peter stone, photoelectric effect, photoemission, photovoltaic cell, processing, room temperature, shigenori ueda, spin, spintronic application, spintronic technology, spring8, storage, surface reaction, synchrotron radiation, xray angle, yoshiyuki yamashita

Berkeley Lab Researchers Unlock Ferromagnetic Secrets of Promising Materials

Spintronic technology, in which data is processed on the basis of electron “spin” rather than charge, promises to revolutionize the computing industry with smaller, faster and more energy efficient data storage and processing. Materials drawing a lot of attention for spintronic applications are dilute magnetic semiconductors – normal semiconductors to which a small amount of magnetic atoms is added to make them ferromagnetic. Understanding the source of ferromagnetism in dilute magnetic semiconductors has been a major road-block impeding their further development and use in spintronics. Now a significant step to removing this road-block has been taken.

A multi-institutional collaboration of researchers led by scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), using a new technique called HARPES, for Hard x-ray Angle-Resolved PhotoEmission Spectroscopy, has investigated the bulk electronic structure of the prototypical dilute magnetic semiconductor gallium manganese arsenide. Their findings show that the material’s ferromagnetism arises from both of the two different mechanisms that have been proposed to explain it. (more…)

Freezing Electrons in Flight

By Guest PostOctober 13, 2012Science1878, arizona, artificial, arvinder sandhu, atmosphere, atom, attosecond, camera, chemical process, destruction, eadweard muybridge, earth, electron, electron emission, electronic devices, electronic motion, emulsion plate, excited atom, femtosecond, formation, ground, henry timmers, high energy, horse, iconic series, laser flash, laser pulses, microscopic dynamics, molecular process, muybridge, mystery, natural, niranjan shivaram, oxygen molecule, ozone, phenomena, photo, photograph, physical, quintillionths, real-time, second, stroboscopy, super excited, technique, touch, ultrafast, ultraviolet light, university, upper atmosphere, zeptosecond

Using the world’s fastest laser pulses, which can freeze the ultrafast motion of electrons and atoms, UA physicists have caught the action of molecules breaking apart and electrons getting knocked out of atoms. Their research helps us better understand molecular processes and ultimately be able to control them in many possible applications.

In 1878, a now iconic series of photographs instantly solved a long-standing mystery: Does a galloping horse touch the ground at all times? (It doesn’t.) The images of Eadweard Muybridge taken alongside a racetrack marked the beginning of high-speed photography.

Approximately 134 years later, researchers in the University of Arizona department of physics have solved a similar mystery, one in which super-excited oxygen molecules have replaced the horse, and ultrafast, high-energy laser flashes have replaced Muybridge’s photo emulsion plates. (more…)

First Stars, Galaxies Formed more Rapidly than Expected

By Guest PostSeptember 9, 2012Scienceanalysis, anisotropy probe, Antarctica, astronomer, background, Berkeley, california, christian reichardt, cmb, cosmic microwave, cosmological evolution, data, earth axis, electron, Epoch, Galaxy, geographic, herschel satellite, high resolution, hydrogen atom, image, john carlstrom, kavli foundation, microwave, millimeter wavelength, national, neutral, neutral gas, oliver zahn, period, plasma, polar plateau, proton, radiation, reionization, s chandrasekhar, science foundation, south pole, star, telescope, ultraviolet light, universe, university, wilkinson

Analysis of data from the National Science Foundation’s South Pole Telescope, for the first time, more precisely defines the period of cosmological evolution when the first stars and galaxies formed and gradually illuminated the universe. The data indicate that this period, called the epoch of reionization, was shorter than theorists speculated — and that it ended early.

“We find that the epoch of reionization lasted less than 500 million years and began when the universe was at least 250 million years old,” said Oliver Zahn, a postdoctoral fellow at the Berkeley Center for Cosmological Physics at the University of California, Berkeley, who led the study. “Before this measurement, scientists believed that reionization lasted 750 million years or longer, and had no evidence as to when reionization began.” (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…)