http://phys.org/physics-news/physics/ en-us PhysOrg Team Phys.Org provides the latest news on physics, materials, nanotech, science and technology. Scientists have developed an X-ray imaging method that could drastically improve the contrast of computed tomography (CT) scans whilst reducing the radiation dose deposited during the scan. The new method is based on the combination of the high contrast obtained by an X-ray technique known as grating interferometry with the three-dimensional capabilities of CT. It is also compatible with clinical CT apparatus, where an X-ray source and detector rotate continuously around the patient during the scan. The results are published in Proceedings of the National Academy of Sciences (PNAS) dated June 4-8, 2012. http://phys.org/news258036502.html Physics - General Physics 2012-06-04T15:00:10-07:00 In the biggest result of its kind in more than ten years, physicists have made the most sensitive measurements yet in a decades-long hunt for a hypothetical and rare process involving the radioactive decay of atomic nuclei. http://phys.org/news258036635.html Physics - General Physics 2012-06-04T14:00:01-07:00 Researchers from the Institute of Materials Structure Science at KEK and RIKEN discovered a new phenomenon, “electronic ferroelectricity,” through electric polarization measurements and synchrotron X-ray diffraction experiments. http://phys.org/news258019077.html Physics - General Physics 2012-06-04T08:58:13-07:00 (Phys.org) -- In the centennial year of Max von Laue’s discovery that X-ray diffraction can be used to unravel the atomic architecture of molecules, a new approach to the determination of high-resolution structures has been demonstrated. An international team of researchers has analyzed tiny protein crystals using short pulses of X-ray light from the world’s first hard X-ray free-electron laser, the US Department of Energy’s 300 million dollar Linac Coherent Light Source at Stanford. The study demonstrates the immense potential of free-electron lasers for obtaining the structures of macromolecules from tiny crystals when illuminated with the blazing intensity of the ultrashort free-electron laser X-ray pulses, even though the crystals are destroyed in the process. In the current study, their structural analysis reveals details with a spatial resolution of 0.2 millionth of a millimeter. http://phys.org/news257763759.html Physics - General Physics 2012-06-01T10:02:50-07:00 (Phys.org) -- Whether the Higgs boson exists could be settled by the end of summer, say University of Michigan physicists involved in the search for the missing piece of particle physics' Standard Model. http://phys.org/news257757517.html Physics - General Physics 2012-06-01T08:20:51-07:00 In this month's Physics World, Sidney Perkowitz, Candler Professor of Physics Emeritus at Emory University, explains how applied physics led to the innovation of flameless cooking in the late 19th century and addresses the challenge of feeding a rapidly growing population in a cleaner, more efficient way. http://phys.org/news257743170.html Physics - General Physics 2012-06-01T04:22:02-07:00 An international team led by SLAC National Accelerator Laboratory has proved how the world's most powerful X-ray laser can assist in cracking the structures of biomolecules, and in the processes helped to pioneer critical new investigative avenues in biology. http://phys.org/news257689199.html Physics - General Physics 2012-05-31T14:00:16-07:00 While SLAC's Linac Coherent Light Source was designed to push the limits as a high-energy X-ray laser, users' requests have led staff at the facility to successfully step it back to a lower minimum energy for some experiments. http://phys.org/news257585745.html Physics - General Physics 2012-05-30T09:00:02-07:00 (AP) — Nestled nearly 5,000 feet beneath the earth in the gold boom town of Lead, S.D., is a laboratory that could help scientists answer some pretty heavy questions about life, its origins and the universe. http://phys.org/news257574193.html Physics - General Physics 2012-05-30T05:40:01-07:00 The widely-held belief that moisture in the air during humid conditions helps make a cricket ball swing has been clean bowled in a scientific study. http://phys.org/news257570329.html Physics - General Physics 2012-05-30T04:19:06-07:00 (Phys.org) -- Why do the bubbles in a glass of stout beer such as Guinness sink while the beer is settling, even though the bubbles are lighter than the surrounding liquid? That’s been a puzzling question until now, as a team of mathematicians from the University of Limerick has shown that the sinking bubbles result from the shape of a pint glass, which narrows downwards and causes a circulation pattern that drives both fluid and bubbles downwards at the wall of the glass. So it’s not just the bubbles themselves that are sinking (in fact, they're still trying to rise), but the entire fluid is sinking and pulling the bubbles down with it. http://phys.org/news257510798.html Physics - General Physics 2012-05-29T11:46:54-07:00 Friction is a key phenomenon in applied physics, whose origin has been studied for centuries. Until now, it has been understood that mechanical wear-resistance and fluid lubrication affect friction, but the fundamental origin of sliding friction has been unknown. http://phys.org/news257503639.html Physics - General Physics 2012-05-29T09:49:17-07:00 NPL scientists have made the first measurements of airborne acoustic free-field pressures using a laser technique based on photon correlation spectroscopy. http://phys.org/news257496263.html Physics - General Physics 2012-05-29T07:45:43-07:00 New York University physicists have developed a method that models biological cell-to-cell adhesion that could also have industrial applications. http://phys.org/news257415266.html Physics - General Physics 2012-05-28T15:00:01-07:00 (Phys.org) -- In a recently published paper, the LHCb Collaboration has reported on a possible deviation from the Standard Model. Theorists are now working to calculate precisely this effect and to evaluate the implications that such unexpected result could have on the established theory. http://phys.org/news257408731.html Physics - General Physics 2012-05-28T07:25:42-07:00 (Phys.org) -- An international collaboration of scientists, including Thomas Blum, associate professor of physics, is reporting in landmark detail the decay process of a subatomic particle called a kaon – information that may help answer fundamental questions about how the universe began. http://phys.org/news257152899.html Physics - General Physics 2012-05-25T08:21:53-07:00 Many people anticipating the creation of an invisibility cloak might be surprised to learn that a group of American researchers has created 25 000 individual cloaks. http://phys.org/news257094354.html Physics - General Physics 2012-05-24T19:00:01-07:00 Researchers from Vestfold University College in Norway have created a simple, efficient energy harvesting device that uses the motion of a single droplet to generate electrical power. http://phys.org/news257100462.html Physics - General Physics 2012-05-24T18:10:01-07:00 Physicists have trapped and cooled exotic particles called excitons so effectively that they condensed and cohered to form a giant matter wave. http://phys.org/news257080023.html Physics - General Physics 2012-05-24T12:07:27-07:00 (Phys.org) -- The laws of classical electromagnetism that were developed in the 19th century are the same laws that scientists use today. They include Maxwell’s four equations along with the Lorentz law, which describes the force exerted by electric and magnetic fields on charged particles. But Masud Mansuripur, a professor of Optical Sciences at The University of Arizona in Tucson, is now arguing that the Lorentz law of force is incompatible with special relativity and momentum conservation, and should be abandoned. In a recent issue of Physical Review Letters, he has suggested replacing the Lorentz law with a more general expression of electromagnetic force density, such as one developed by Albert Einstein and Jakob Laub in 1908. http://phys.org/news257069877.html Physics - General Physics 2012-05-24T09:50:01-07:00 'Tractor beams' of light that pull objects towards them are no longer science fiction. Haifeng Wang at the A*STAR Data Storage Institute and co-workers have now demonstrated how a tractor beam can in fact be realized on a small scale. http://phys.org/news257068727.html Physics - General Physics 2012-05-24T09:20:01-07:00 First of all, the neutrinophone isn’t really a phone. It has the potential to be used for communication across immense distances—including into outer space—but even Jeff Nelson says the neutrinophone’s debut was “little more than an outreach stunt.” http://phys.org/news257060289.html Physics - General Physics 2012-05-24T06:38:34-07:00 Although it's invisible, dark matter accounts for at least 80 percent of the matter in the universe. No one knows what it is, but most scientists would bet on weakly interacting massive particles, or WIMPs. http://phys.org/news256998676.html Physics - General Physics 2012-05-23T13:31:51-07:00 Plutonium is the most complex element in the periodic table, yet it is also one of the most poorly understood ones. But now a well-known scientific technique, nuclear magnetic resonance (NMR) spectroscopy, may turn out to be the perfect tool for uncovering some of plutonium’s mysteries. http://phys.org/news256994284.html Physics - General Physics 2012-05-23T12:30:01-07:00 (Phys.org) -- A team of scientists from the University of Hawaii are working on microrobots created from bubbles of air in a saline solution. The bubbles take on their title of “robots” as a laser is deployed to work as an engine to power the bubbles’ directions and speed. The microrobots follow the positions of the projected light; multiple microrobots can be controlled at once. Among the demonstrations is an example of how bubble microrobots can pass around glass microbeads. Using a fine-tipped syringe filled with air and saline solution, the scientists went to work on making these robots out of bubbles. http://phys.org/news256993894.html Physics - General Physics 2012-05-23T12:11:49-07:00 Based on research she conducted for her doctoral dissertation several years ago, Jatila van der Veen, a lecturer in the College of Creative Studies at UC Santa Barbara and a research associate in UC Santa Barbara's physics department, created a new approach to introductory physics, which she calls "Noether before Newton." Noether refers to the early 20th-century German mathematician Emmy Noether, who was known for her groundbreaking contributions to abstract algebra and theoretical physics. http://phys.org/news256988946.html Physics - General Physics 2012-05-23T10:50:23-07:00 (Phys.org) -- An electron’s spin is separate from its motion, and is suitable for use in both highly-precise magnetic sensing as well as a qubit in quantum computing. Recently, scientists at the University of Konstanz in Germany have theoretically investigated the coupling of electron spin in carbon nanotube quantum dots, showing that the carbon nanotube’s nanomechanical vibrations can significantly affect the spin of an electron trapped on it. Moreover, their findings also theoretically show that the carbon nanotube itself can be affected by the electron’s spin. The researchers state that their findings have important implications for magnetic and mass nanosensors, quantum computing and other nanoscale applications. http://phys.org/news256979923.html Physics - General Physics 2012-05-23T08:50:01-07:00 (Phys.org) -- JQI experimentalists under the direction of Ian Spielman are in the business of using lasers to create novel environments for neutral atoms. For instance, this research group previously enticed electrically neutral atoms to act like charged particles moving in magnetic and electric fields. The behavior of particles in strong electromagnetic fields, along with arbitrary control of the said fields, is central to both condensed matter physics, and quantum information science. http://phys.org/news256894798.html Physics - General Physics 2012-05-22T08:40:32-07:00 (Phys.org) -- Quantum physics and plant biology seem like two branches of science that could not be more different, but surprisingly they may in fact be intimately tied. http://phys.org/news256889606.html Physics - General Physics 2012-05-22T07:13:33-07:00 (Phys.org) -- A team of French scientists studying the properties of Leidenfrost drops has found that liquid oxygen drops can be manipulated and controlled using a magnetic field at room temperature. They describe their work and the properties they’ve uncovered in a paper to be published in the journal Physical Review E. http://phys.org/news256812575.html Physics - General Physics 2012-05-21T10:20:01-07:00