Aestus Ajith

Einstein with Edwin Hubble, in 1931, at the Mount Wilson Observatory in California, looking through the lens of the 100-inch telescope through which Hubble discovered the expansion of the universe in 1929.  Courtesy of the Archives, Calif Inst of Technology. In 1917, a year after Albert Einstein’s  general theory of relativity  was published—but still two years before he would become the international celebrity we know—Einstein chose to tackle the  entire universe . For anyone else, this might seem an exceedingly ambitious task—but this was Einstein. Einstein began by applying his  field equations of gravitation  to what he considered to be the entire universe. The field equations were the mathematical essence of his general theory of relativity, which extended Newton’s theory of gravity  to realms where speeds approach that of light and masses are very large. But his math was better than he wanted to believe—...

How does an autistic child take in information when he sits in a classroom abuzz with social activity? How long does it take someone with multiple sclerosis, which slows activity in the brain, to process the light bouncing off the windshield while she drives? Until recently, the answers to basic questions of how diseases affect the brain – much less the ways to treat them – were lost to the limitations on how scientists could study brain function under real-world conditions. Most technology immobilized subjects inside big, noisy machines or tethered them to computers that made it impossible to simulate what it’s really like to live and interact in a complex world. Adam Gazzaley, MD, PhD But now UC San Francisco neuroscientist  Adam Gazzaley , MD, PhD, is hoping to paint a fuller picture of what is happening in the minds and bodies of those suffering from brain disease with his new lab,  Neuroscape , which bridges the worlds of neuroscience and high-tech. In the N...

iStockphoto/narvikk Tuning Ideal Tensile Strengths and Intrinsic Ductility of bcc Refractory Alloys Liang Qi and D. C. Chrzan Phys. Rev. Lett.   112 ,  115503  (2014) Published March 19, 2014 Fusion reactors and turbine engines contain components made of metals that are ductile at high temperatures but become brittle and prone to cracking at room temperature. This brittleness can lead to machine failures that are both dangerous and expensive to fix. New theoretical calculations now show that an unexpected route to making certain alloyed metals more ductile at room temperature is to tune their density of conduction electrons. A brittle metal tends to crack under an applied force, while ductile metals incur a permanent stretch. Which property dominates depends both on the intrinsic crystalline arrangement of the atoms and the presence of defects: brittle materials tend to keep their crystalline symmetry until the moment that they fail; ductile materia...

K. Kobayashi  et al. , Phys. Rev. Lett. (2014) Observation of Orbital Resonance Hall Effect in (TMTSF)2ClO4 Kaya Kobayashi, H. Satsukawa, J. Yamada, T. Terashima, and S. Uji Phys. Rev. Lett.   112 ,  116805  (2014) Published March 20, 2014 Quasi- 1 D organic conductors are made up of an array of long molecular strands that confine the flow of electrons to essentially one dimension. This reduced dimensionality results in unique behaviors, such as angle-dependent magnetoresistance. New experiments with a particular quasi- 1 D organic conductor have revealed an unexpected Hall effect. As reported in  Physical Review Letters , the characteristic Hall resistance oscillates as the orientation of the magnetic field is rotated with respect to the conductor’s lattice structure. The Hall effect occurs when a magnetic field is applied perpendicular to the current flowing in a material. The magnetic force causes charge carriers to accumulate on the s...

Chukman So Antimatter Interferometry for Gravity Measurements Paul Hamilton, Andrey Zhmoginov, Francis Robicheaux, Joel Fajans, Jonathan S. Wurtele, and Holger Müller Phys. Rev. Lett.   112 ,  121102  (2014) Published March 25, 2014 Does antimatter feel the same gravitational pull as ordinary matter? The standard model of particle physics assumes this is the case, but experimental evidence remains hard to gather: measurements are complicated by the fact that antimatter is rare and annihilates when brought into contact with matter. Still, researchers are eager to test this assumption, since the standard model cannot explain the gravitational behavior of  95 %  of the Universe’s matter nor the abundance of matter vs antimatter. As reported in  Physical Review Letters , experts in antihydrogen and atom interferometry are working together to design an interferometer that could measure the free-fall acceleration of any species of atoms, in p...

R. Shimizu  et al. , Phys. Rev. Lett. (2014) Evidence of Liquid-Liquid Transition in Triphenyl Phosphite from Time-Resolved Light Scattering Experiments Ryotaro Shimizu, Mika Kobayashi, and Hajime Tanaka Phys. Rev. Lett.   112 ,  125702  (2014) Published March 26, 2014 The most familiar phase transitions of water are when it freezes into a solid or evaporates into a gas. But water, like a small handful of other liquids, can also exist in multiple liquid states, which are distinguished by their density and the local order of the molecules. Such liquid-liquid phase transitions are rare, and finding new ones would allow scientists to probe the fundamental nature of the liquid state. Writing in  Physical Review Letters , Hajime Tanaka, and co-workers from the University of Tokyo, Japan, present optics experiments showing that triphenyl phosphate (TPP)—a material commonly used as a flame retardant—exhibits a liquid-liquid phase transition. Rese...

Los Alamos postdoctoral fellow William Rice holds a crystal of strontium titanate up to the light. This crystal, previously thought to be nonmagnetic, turns out to have surprising magnetic features when treated with special “circularly polarized” light. (Phys.org) —Interest in oxide-based semiconductor electronics has exploded in recent years, fueled largely by the ability to grow atomically precise layers of various oxide materials. One of the most important materials in this burgeoning field is strontium titanate (SrTiO3), a nominally nonmagnetic wide-bandgap semiconductor, and researchers at Los Alamos National Laboratory have found a way to magnetize this material using light, an effect that persists for hours at a time. "One doesn't normally think of this material as being able to support magnetism. It's supposed to be useful – but magnetically uninteresting – stuff. So when we started shining  light  on it and saw what appeared to be extremely long-lived magnet...