Waves & Packets
Aug. 18, 2012

Interview with Ted Williams: New director of the South African Astronomical Observatory
Waves and Packets
Professor Theodore Williams has accepted the position of director of the South African Astronomical Observatory. Formerly, he was a professor at Rutgers University. He is the chairman of the board of the Southern African Large Telescope. His research interests include optical observations of extragalactic objects and instrument development. Current research projects are: the measurement of the kinematics of both stars and gas in barred spiral galaxies; measuring the velocities of stars in the dense cores of globular clusters; detecting and measuring the velocities of planetary nebula surrounding elliptical galaxies; and refining the Tully-Fisher technique for measuring the distances to galaxies. Waves and Packets interviewed Williams at the 2012 Annual Meeting of the South African Institute of Physics in Pretoria about his new position as director of SAAO.More

South African astronomers hold town meeting
NSBP
Astronomers and government officials from the Department of Science and Technology and the National Research Foundation gathered in Pretoria, South Africa, on July 8-9 to generally "strengthen the astronomy community in South Africa" and specifically "to share ideas and concerns, to improve communications" and to "create more coherence in this vast and exciting terrain of astronomy in South Africa," according to Nithaya Chetty, convener and head of astronomy at the NRF.

Government speakers made the following clear: Because of the advantages of South Africa's geographic location, government is willing to invest heavily in astronomy, astrophysics and cosmology. Government expects however, returns to South African society in the form of human capital development, both in science and engineering, and through public outreach significant increases in science awareness and scientific literacy.More

Interview with Tony Beasly: New director of the National Radio Astronomy Observatory
Waves and Packets
Last February the overseer of the National Radio Astronomy Observatory appointed Dr. Anthony Beasly as the next NRAO director. Originally from Australia, Beasly has had a distinguished career in radio astronomy. He has played a key role in the planning and commissioning of several major instruments and facilities. In his most recent appointment his skills were used in ecological research, where those colleagues too have large networks of major scientific facilities. In a wide-ranging interview with Waves and Packets, Beasly discusses the future of NRAO and of radio astronomy in general, global collaborations like the Square Kilometer Array and VLBI, the U.S. astronomy portfolio in tough budgetary times and the promise of citizen-science in making profound discoveries.More

Prototype 'Mott transistor' developed
Physics World
Researchers in Japan have unveiled a prototype of a "Mott transistor." In a field effect transistor, when it is in the "on state" a voltage is applied between the source electrode and the drain electrode. Charge carriers then move in this field and the aim is for there to be as much current as possible. In the "off state" there is no voltage and as little current as possible. Finding a material where the off current is zero and on current is large is a technological challenge, but using a Mott insulator could present a solution.

Mott insulators are materials that should behave as metals according to conventional band theories but that act as insulators under certain conditions owing to quantum-mechanical correlations between neighboring electrons. For reasons that are complex and not entirely understood, however, sudden phase transitions can be induced between the insulating state and the metallic state. Among other things, this metal–insulator transition can be induced by an electric field. While the gate voltage in an ordinary transistor simply modulates the resistance of a semiconductor, the gate voltage in a Mott transistor could turn an insulator into a metal. Various research groups have tried to produce Mott transistors in the past, but they have failed to generate the electric fields needed to induce the metal–insulator transition at the surface of the Mott insulator. This new device is described in Nature.More

Graphene layers can make sensitive optical detectors
American Physical Society
Like many other materials, graphene has two different types of vibrational waves. Higher-energy waves involve neighboring atoms moving in different directions. These "optical" vibrations ultimately limit the extraordinary acceleration of electrons in graphene. But gently heated electrons do not have enough energy to create these vibrations. Instead, they have to share their energy with "acoustic" vibrational modes, in which nearby atoms all move in synchrony, as in ordinary sound waves. In a report published in Physical Review Letters a team of physicists working in France report painstaking measurements of electron-acoustic phonon coupling constant in monolayer graphene. More

What not to do with your physics education
Science Careers
Brooke Allen offers some thoughts on the perils of physics on Wall Street. More

New experiment achieves extraordinarily large negative refractive indices for radio waves
Ars Technica
A multinational team of researchers has constructed a metamaterial made of aluminum gallium arsenide strips on top of a gallium arsenide substrate. The construction produced a two-dimensional electron gas where the electrons' motion was confined to the interface between the strips and the substrate. At very cold temperatures, the material bent light much more strongly than has been accomplished before. In the process, it provides a new understanding of kinetic inductance, i.e., the Newtonian acceleration of electrons via the interaction with light. The result where their two-dimensional electron gas has a larger kinetic inductance than three-dimensional metals is reported in Nature.More

Research team fabricates artificial retinas with high pixel density
Laser Focus World
Retinal degenerative diseases like age-related macular degeneration and retinitis pigmentosa cause loss of "image capturing" photoreceptors. Most of the inner "image-processing" retinal neurons typically are relatively well preserved. Methods to restore sight to the visually impaired typically involve external cameras and implanted wired electrode arrays to stimulate these neurons; however, the required components are bulky, pixel density is low and the delivered image cannot be scanned naturally by the eye. In response to these drawbacks, researchers have developed wireless, photovoltaically driven, subretinal arrays of photodiodes to stimulate the inner retinal neurons that transmit signals to retinal ganglion cells when illuminated with pulsed near-infrared light. The scheme eliminates the need for complex electronics and wiring and preserves the natural link between image perception and eye movement. The system and underlying physics are described in Nature Photonics. More

Ed Witten explains why quantum mechanics says a black hole should be able to let some things out
PhysOrg
Science is running a series of reviews and perspectives written by leaders in the field on the current state of knowledge and theories regarding black holes. Some discuss what is believed to happen if two black holes collide, others describe what happens as binary stars are sucked up by black holes and whether intermediate-size black holes really exist. Yet another by doctoral fellow Rubens Reis, discusses a lucky break that allowed scientists to listen to the "cry" of the last bits of some matter just before being consumed by another black hole. But generating the most interest perhaps, is an article by Edward Witten of the Institute for Advanced Study. He argues that one of the most basic beliefs about black holes, namely, that nothing can ever escape its gravitational pull, is wrong, but only sort of.More

Sobering budget outlook for nuclear physics research
American Institute of Physics
Stuart Freedman, chair of the National Research Council committee that wrote NP 2010: An Assessment and Outlook for Nuclear Physics recently gave a briefing to the President's Council of Advisors on Science and Technology. In discussing the changes in the funding outlook that occurred during the preparation of the report he said that the U.S. Department of Energy budget was on a trajectory that was increasing at a reasonable rate that would accommodate all of the items recommended in the long-range plan. But as the committee was ending its work and its report issued, new budget realities began to emerge. The budget did not increase. In fact, it decreased slightly. And it is not recognized that the program conceived just months before is not longer practical withing existing budgets.More

Nuclear physics slated for big cuts in Italy
Physics World
Italy's National Institute of Nuclear Physics is slated to bare severe cuts to its budget over the next three years. INFN stands to lose just over $11 million this year — some 3.8 percent of its budget — and more than $29 million (10 percent) in both 2013 and 2014. These cuts are apparently much larger than for other research areas in the Italian government's research funding portfolio. Fabiola Gianotti, spokesperson for CERN's ATLAS experiment, and Guido Tonelli, former spokesperson of the neighboring CMS detector, have written an open letter to the media saying that if the cuts are confirmed, "the INFN would find it impossible to continue its activities effectively and to honor its national and international commitments."More

New research on noninvasive heart and cancer imaging reported in Journal of Biomedical Optics
SPIE
The July issue of SPIE's Journal of Biomedical Optics is a special section on noninvasive technologies for imaging breast, heart and other tissues. Papers cover advances such as using molecular resonance imaging for a noninvasive, portable test for breast cancer, optical coherence tomography for monitoring of heartbeat arrhythmias such as flutter and fibrillation, and other biomedical applications of diffuse optics imaging technologies. The new special section on biophotonics topics is the latest in a series published every two years in the Journal of Biomedical Optics in conjunction with the biennial Biophotonics Graduate Summer School on the island of Ven, Sweden. More

Topological insulator researchers bag Dirac prize
Physics World
Three condensed-matter physicists, who have advanced our understanding of a strange type of material known as a "topological insulator," have won this year's Dirac medal from the International Centre for Theoretical Physics in Trieste, Italy. Duncan Haldane of Princeton University, Charles Kane of the University of Pennsylvania and Shoucheng Zhang of Stanford University, all in the U.S., have scooped the $5,000 prize, which is named after the British Nobel-prize-winning theorist Paul Dirac.

Topological insulators are currently one of the hottest topics in condensed-matter physics. Insulators on the inside, they manage to conduct electricity on their surface thanks to special surface electronic states that are "topologically protected," which means that — unlike ordinary surface states — they cannot be destroyed by impurities or imperfections. Moreover, the conducting electrons arrange themselves into spin-up electrons traveling in one direction and spin-down electrons traveling in the other. Such a "spin current" could be useful for anyone wishing to build a practical "spintronic" device that exploits the spin, rather than the charge, of the electrons. More

Long-predicted fluctuations in cell membranes observed for 1st time
National Institute of Standards and Technology
A long-standing mystery in cell biology may be closer to a solution thanks to measurements taken at the National Institute of Standards and Technology and France's Institut Laue-Langevin, where scientists have used neutron spin echo spectroscopy to observe changes in the thickness of a model cell membrane for the first time. The findings, which are reported in Physical Review Letters, confirm that long-predicted fluctuations occur in the membranes, may help biologists understand many basic cellular functions, including how membranes form pores.More

The physics of how animals shake themselves dry
The Washington Post
Researchers at the Georgia Institute of Technology in Atlanta have studied 16 soggy species, including mice, dogs, tigers and bears, and found that each creature tunes its shaking speed to get as dry as possible without wasting too much energy. Small animals shake the fastest in order to generate the force required to overcome the surface tension that holds water to fur, whereas large animals — whose size makes it easier to generate sufficient force — move slower to reach a comparable degree of dryness. Under some conditions animals can generate forces between 10 and 70 times that of gravity — high enough that the animals have to close their eyes to prevent damage from the extreme centrifugal forces. Their results are published in the Journal of the Royal Society Interface.More

Update: CERN physicists break record for hottest man-made material
PhysOrg
The ALICE collaboration has announced that they have achieved a quark-gluon plasma temperature that is 38 percent higher than the previous record-setting temperature achieved at Brookhaven National Lab's Relativistic Heavy Ion Collider. The ALICE team at CERN uses beams of lead in the collider, while the ATLAS and CMS teams, which of course announced the Higgs result in July, use proton beams. Breaking temperature records is not where the interesting physics lays however. RHIC has reportedly found evidence for hadronization in its quark-gluon plasma. And ALICE is more interested in the conditions under which quark-gluon plasma comes to exist in hopes of better understanding its properties. ALICE reported their first preliminary results from the large sample of Pb-Pb collisions recorded in 2011 at the Quark Matter 2012 Conference the week of Aug. 13, including the tracking of charm energy loss. More

Phoenix cluster sets record pace at forming stars
NASA
Astronomers have observed that stars are forming in the Phoenix cluster at the highest rate ever observed for the middle of a galaxy cluster. The object also is the most powerful producer of X-rays of any known cluster and among the most massive. The data also suggest the rate of hot gas cooling in the central regions of the cluster is the largest ever observed. The results, which were obtained via NASA's Chandra X-ray Observatory, the National Science Foundation's South Pole Telescope and eight other world-class observatories, may force astronomers to rethink how these colossal structures and the galaxies that inhabit them evolve. The Phoenix cluster is located about 5.7 billion light years from Earth. It is named not only for the constellation in which it is located, but also for its remarkable properties. The results are published in Nature.More

National Society of Black Physicists jobs board postings
NSBP
Chamberlain Fellowship
Assistant Professor of Physics, tenure track
Faculty Positions in Science, Technology, and Innovation
Project Leader: Nanoscale Measurements for Energy Storage Technologies
LBNL Divisional Fellow — Theoretical Particle Physics
2-Year Full-Time Postdoctoral Fellowship in Acoustics
Divisional Fellow — Experimental Particle Physics
IceCube Computing Facilities Manager
JWST Mission System Engineer
Assistant Professor — Experimental Condensed Matter and Materials Physics — Ohio State University
Deputy Director, National High Magnet Field Laboratory
National Astrophysics and Space Science Program
Postdoctoral Research Associate Positions


More

Increase your options for graduate or REU program admissions
NSBP
The NSBP GradApps and REUApps services are open to all students and allows them to upload all the elements of an admissions application, including academic and work history, transcripts, letters of recommendation and a personal statement. Graduate and REU programs can subscribe to these databases to increase the programs' applicant pool, while at the same time allowing students can put their credentials in front of more programs than to which they would otherwise apply. More

Latest research from Nanotechnology
IOP Publishing
Low voltage flexible nonvolatile memory with gold nanoparticles embedded in poly(methyl methacrylate)

Utilizing insulating nanoparticles as the spacer in laminated flexible polymer solar cells for improved mechanical stability

Multifunctional, flexible electronic systems based on engineered nanostructured materials

Continuous phase-shift lithography with a roll-type mask and application to transparent conductor fabrication

Graphene-based photonic devices for soft hybrid optoelectronic systemsMore

Latest research from Wave Motion
Wave Motion
Particle dynamics in the KdV approximation

The elastodynamic Liénard–Wiechert potentials and elastic fields of nonuniformly moving point and line forces

Reconstruction of the impedance Schrödinger equation from the modulus of the reflection coefficients

Lorentz-covariant electromagnetic fields in (N+1)-spacetime—An axiomatic approach to special relativity

A nonstandard wave decomposition to ensure the convergence of Debye series for modeling wave propagation in an immersed anisotropic elastic plateMore