Physics
Scientists find way to monitor elusive collisions in space
April 24, 2013 9:10 am | News | CommentsMany collisions occur between asteroids and other objects in our solar system, but scientists are not always able to detect or track these impacts from Earth. Space scientists at the University of California, Los Angeles have now devised a way to monitor these types of collisions in interplanetary space by using a new method to determine the mass of magnetic clouds that result from the impacts.
Cause of LED efficiency droop finally revealed
April 23, 2013 9:56 am | News | CommentsResearchers at University of California, Santa Barbara in collaboration with colleagues at the École Polytechnique in France, have conclusively identified Auger recombination as the mechanism that causes light-emitting diodes (LEDs) to be less efficient at high drive currents.
Physicists find right (and left) solution for on-chip optics
April 23, 2013 7:42 am | News | CommentsA Harvard University-led team of researchers has created a new type of nanoscale device that converts an optical signal into waves that travel along a metal surface. Significantly, the device can recognize specific kinds of polarized light and accordingly send the signal in one direction or another.
NASA sees distant planets that seem ideal for life
April 19, 2013 12:33 pm | by Seth Borenstein, AP Science Writer | News | CommentsThe planet-hunting Kepler telescope has discovered two planets that seem like ideal places for some sort of life to flourish. According to scientists working with the NASA telescope, they are just the right size and in just the right place near their star. The discoveries, published online Thursday, mark a milestone in the search for planets where life could exist.
New solar cell coating could boost efficiency
April 18, 2013 2:44 pm | by David L. Chandler, MIT News Office | News | CommentsThroughout decades of research on solar cells, one formula has been considered an absolute limit to the efficiency of such devices in converting sunlight into electricity: Called the Shockley-Queisser efficiency limit, it posits that the ultimate conversion efficiency can never exceed 34% for a single optimized semiconductor junction. Now, researchers have shown that there is a way to blow past that limit.
Discovery paves the way for ultra-fast high-resolution imaging in real time
April 18, 2013 10:51 am | News | CommentsScientists in Australia have recently demonstrated that ultra-short durations of electron bunches generated from laser-cooled atoms can be both very cold and ultra-fast. The low temperature permit sharp images, and the electron pulse duration has a similar effect to shutter speed, potentially allowing researchers to observe critical but quick dynamic processes, such as the picosecond duration of protein folding.
Team produces best image yet of atoms moving real time
April 17, 2013 4:59 pm | News | CommentsUsing an ultra-bright electron source, scientists at the University of Toronto have recorded atomic motions in real time, offering a glimpse into the very essence of chemistry and biology at the atomic level. Their recording is a direct observation of a transition state in which atoms undergo chemical transformation into new structures with new properties.
Researchers create novel optical fibers
April 17, 2013 2:16 pm | News | CommentsResearchers at the University of Wisconsin-Milwaukee have found a new mechanism to transmit light through optical fibers. Their discovery marks the first practical application of a Nobel-Prize-winning phenomenon that was proposed in 1958. The team harnessed “Anderson localization” to create an optical fiber with a strong scattering mechanism that traps the beam of light as it traverses the fiber.
Device launches plasma, holds it together through the air
April 16, 2013 10:12 pm | News | CommentsA University of Missouri engineer has built a system that is able to launch a ring of plasma as far as two feet. Plasma is commonly created in the laboratory using powerful electromagnets, but previous efforts to hold the super-hot material through air have been unsuccessful. The new device does this by changing how the magnetic field around the plasma is arranged.
Cryogenic dark matter search adds new intrigue with latest result
April 16, 2013 10:21 am | News | CommentsPhysicists operating an experiment located half a mile underground in Minnesota reported this weekend that they have found possible hints of dark-matter particles. The Cryogenic Dark Matter Search experiment has detected three events with the characteristics expected of dark matter particles.
Physicists close loophole for entangled photonic systems
April 15, 2013 1:15 pm | News | Comments“Local realism” is a view of physics in which the properties of physical objects exist independently of whether or not they are observed by anyone—the “realism”—and in which no physical influence can propagate faster than the speed of light—the “locality”. Recent research at the Max Planck Institute of Quantum Optics may have eliminated the last experimental loopholes that has allowed this world view to persist.
Smashing glass at the molecular level
April 15, 2013 8:05 am | News | CommentsWhether gas trapped under a frozen water layer flows through cracks or bursts out depends on the layer's depth and temperature, according to scientists at Pacific Northwest National Laboratory. The water isn't crystalline ice; it is amorphous solid water, which is disordered and often described as a "frozen" liquid.
U.K. team improves world’s most accurate resistance measurements
April 10, 2013 12:36 pm | News | CommentsCryogenic Ltd and the National Physical Laboratory in the U.K. have designed and developed the most accurate instrument for comparative measurements of electric current. The instrument can now be used by National Measurement Institutes and laboratories around the world, providing a more accurate standard for current ratio, and ensuring current measurement is not a limiting factor in innovation.
Supercomputer assists in crunching LHC data
April 5, 2013 9:42 am | News | CommentsGordon, the unique supercomputer launched last year by the San Diego Supercomputer Center at the University of California, San Diego, recently completed its most data-intensive task so far: rapidly processing raw data from almost one billion particle collisions as part of a project to help define the future research agenda for the Large Hadron Collider (LHC).
Material turns "schizophrenic" on way to superconductivity
April 4, 2013 4:05 pm | News | CommentsRice University physicists on the hunt for the origins of high-temperature superconductivity have published new findings this week about a material that becomes “schizophrenic”—simultaneously exhibiting the characteristics of both a metallic conductor and an insulator. In a theoretical analysis in Physical Review Letters, Rice physicists offer an explanation for a strange series of observations described earlier this year by researchers at the Stanford Linear Accelerator Center in Menlo Park, Calif.
Scientists use cloud of atoms as optical memory device
April 4, 2013 9:11 am | News | CommentsTalk about storing data in the cloud. Scientists at the Joint Quantum Institute of NIST and the University of Maryland have taken this to a whole new level by demonstrating that they can store visual images within quite an ethereal memory device—a thin vapor of rubidium atoms. The effort may prove helpful in creating memory for quantum computers.
Quantum tricks drive magnetic switching into the fast lane
April 4, 2013 9:00 am | News | CommentsResearchers at the U.S. Department of Energy’s Ames Laboratory, Iowa State University, and the University of Crete in Greece have found a new way to switch magnetism that is at least 1000 times faster than currently used in magnetic memory technologies. Magnetic switching is used to encode information in hard drives, magnetic random access memory, and other computing devices.
What is behind Einstein’s turbulence?
April 4, 2013 7:48 am | News | CommentsThe American Nobel Prize Laureate for Physics Richard Feynman once described turbulence as “the most important unsolved problem of classical physics”, because a description of the phenomenon from first principles does not exist. This is still regarded as one of the six most important problems in mathematics today, but recent numerical calculations by experts in gravitational physics give an initial insight into the relativistic properties of this mysterious process
Shape from sound: New methods to probe the universe
April 3, 2013 6:11 pm | by Morgan Kelly, Office of Communications, Princeton University | News | CommentsAs the universe expands, it is continually subjected to energy shifts, or “quantum fluctuations,” that send out little pulses of “sound” into the fabric of spacetime. In fact, the universe is thought to have sprung from just such an energy shift. A recent physics paper reports a new mathematical tool that should allow one to use these sounds to help reveal the shape of the universe.
First data released from the Alpha Magnetic Spectrometer
April 3, 2013 5:51 pm | News | CommentsFollowing up on Wednesday’s surprise announcement that a cosmic ray detector on board the International Space Station had possibly made the first instrumented detection of dark matter, an article from the U.S. Department of Energy describes the methodology behind the discovery and what lies ahead for researchers.
Manipulating ultrafast spin at terahertz frequencies
April 3, 2013 10:46 am | News | CommentsThe use of femtosecond light pulses—the fastest man-made event—with photon energies ranging from X-rays (as used for instance at the HZB femto-slicing facility) to terahertz spectral range has proved to be an indispensable tool in ultrafast spin and magnetization dynamics studies. Researchers have recently demonstrated a simple but powerful way of manipulating the spins at these unprecedented speeds.
A new understanding of metallic glass
April 3, 2013 9:00 am | by David L. Chandler, MIT News Office | News | CommentsGelatin sets by forming a solid matrix full of random, liquid-filled pores—much like a saturated sponge. It turns out that a similar process also happens in some metallic glasses, substances whose molecular behavior has now been clarified by new Massachusetts Institute of Technology research detailing the “setting” of these metal alloys.
Switch to a power stroke enables tiny marine crustacean to survive
April 2, 2013 12:59 pm | News | CommentsOlympic swimmers aren’t the only ones who change their strokes to escape competitors. To escape from the jaws and claws of predators in cold, viscous water, marine copepods switch from a wave-like swimming stroke to big power strokes, a behavior that has now been revealed thanks to 3D high-speed digital holography.
Geckos keep firm grip in wet natural habitat
April 2, 2013 12:50 pm | News | CommentsA paper published this week offers a comprehensive answer to the long-debated question of how geckos are able to stick to trees and leaves during rainforest downpours. Researchers tackling this problem have discovered that wet, hydrophobic surfaces like those of leaves and tree trunks secure a gecko's grip similar to the way dry surfaces do. This link between “wettability” and adhesion could developers of synthetic adhesives.
Quantum dot commands light
April 2, 2013 10:06 am | by E. Edwards, JQI | News | CommentsAll computers, even the future quantum versions, use logic operations or “gates,” which are the fundamental building blocks of computational processes. Joint Quantum Institute scientists, led by Professor Edo Waks, have performed an ultrafast logic gate on a photon, using a semiconductor quantum dot. The logic is a Controlled-NOT gate, which is significant because it can serve as the basis for any quantum information protocol.
