Waves & Packets
Dec. 1, 2012

Cosmologists propose new paradigm for understanding early universe
Penn State University
Using their technique of loop quantum cosmology, physicists at Penn State University have, for the first time, extended quantum physics and geometry to the extremely high density states that existed in the Planck era, i.e., the first 10-43 seconds of the universe. This new discovery, to be published in Physical Review Letters, provides a conceptual and mathematical framework of quantum gravity for showing that the large-scale structures we now see in the universe evolved from fundamental quantum fluctuations in the geometry of space-time during the Planck epoch. The mathematical framework in this work evolves quite naturally to the anisotropy in the cosmic microwave background, as has been observed. This framework provides new opportunities for testing competing theories of modern cosmology against breakthrough observations expected from next-generation telescopes. More

On characterizing the topology of neutron start crusts
American Physical Society
The matter in the outermost layer, or "crust," of a neutron star is believed to host a variety of phases in which dense regions of nucleons are filled with voids of lower density. The presence of the phases, euphemistically referred to as "nuclear pasta" because of their resemblance to the shapes of lasagna, gnocchi, and spaghetti, may affect the emission of neutrinos, the primary mechanism by which the neutron star cools. In Physical Review C, a team of physicists report that a set of topological and geometric descriptors (volume, area, and Euler characteristic) can accurately identify each pasta phase predicted by a classical molecular dynamics model that is consistent with low- to medium-energy nuclear reactions. The model results in a labeling scheme that could be used to directly map the geometry of phases to its effect on neutrino emission and neutron star cooling. Since the model does not depend on a priori assumptions about the phase structures, the model should also clarify the balance of forces and parameters that lead to the formation of each phase. More

A cautionary tale about preprints and publishers
APS News
Last year a team of physicists in the United Kingdom posted to arXiv a paper entitled, On the reality of the quantum state. The paper was then submitted to Nature for publication. During the refereeing process, the research team leader posted a follow-up paper to arXiv that seemed to refute the findings of the first paper. The second posting to arXiv led to much confusion in both the underlying physics and in the journal's editorial policies. And this is where perhaps the knowledge discovery and communication interests of scientists diverged from Nature's editorial and business interests. Scientists, by using preprint servers like arXiv, want to get new discoveries into the public-realm into scientific debates as soon as possible. Journals like Nature want to publish high-impact, original research papers. And in addition to copyrights, they want to control the privileges and perils of brand placement that come with any publicity covering the discovery. The cautionary tale involving Terry Rudolph, scholarly journals and their editorial and business interests, along with understanding what the quantum wave function really represents, gives physicists a lot to think about.More

Increase your options for graduate or REU program admissions
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

Black hole discovery shakes galaxy evolution models
Science 2.0
The recent discovery of the most massive black hole ever has upended the model that astronomers believe exists between the sizes of black holes and their host galaxies. Black holes exist in the center bulge of galaxies. It is almost axiomatic amongst astronomers that the black hole's mass is approximate 0.1 percent of the mass of the central bulge. The recently discovered black hole in the relatively small galaxy NGC 1277 has a mass that is nearly 59 percent of the mass of the central bulge, and 14 percent of the galaxy's total mass. The implications of this discovery are striking. NC 1277 does not show signs of being the result of a galactic collision, or being effected by other galaxies in any way. So it appears to have evolved 'naturally' this way, i.e., with a presumptively out-of-proportion black hole. As mentioned in the Nature paper, five other galaxies have been identified that might have over-massive black holes; more could be out there. And it is not yet even hypothesized as to where such galaxies fit in the known evolution sequence of galaxies.More

Phase diagrams of magnesium oxide under extreme conditions could explain exoplanet properties
Ars Technica
The discovery of more and more exoplanets has expanded the list of metals and metal oxides that scientists have to consider as constituents of planetary cores. In this regard, i.e., in planetary cores where the temperatures and pressures are very high, "metals" can include anything from solid hydrogen, to water ice, to any number of transition metal oxides. Magnesium oxide is representative of rocky planet cores, and a team at Carnegie Institution, Howard University and Lawrence Berkeley Lab has studied the material at pressures up to 1.4 TPa. As reported in Science, they used laser-induced shock compression and found two important phase transitions: one at 8,500 Kelvin and 0.5 TPa, and the other at 10,200 Kelvin and 0.65 TPa. The first transition was presumably to a solid crystal form only heretofore predicted in theoretical calculations. The second transition was apparently a melting from a solid phase to a liquid phase. The implications of this discovery for planetary observations are profound. As planets cool from the initial violent collisions that form them, structural phases in the core material can lead to planetary contraction or expansion. And if the core materials have magnetic properties and they transition to a liquid state, this could mean that dynamos and wandering rotational and magnetic poles could result. More

Flash x-ray laser technique yield 1st protein structure at atomic resolution
Science Magazine
For the first time, so-called 'serial femto-second crystallography' (SFX) has revealed the atomic-level structure of a protein of paramount research interest. The SFX technique depends on ultra-intense, ultra-short, x-ray bursts from a free-electron laser to take snapshots of a continuous steam of tiny protein crystals before the radiation has time to destroy the material. Most protein structures have been found using synchrotron x-ray sources and necessarily large crystals. Getting a protein crystal to grow to sufficient size and that diffracts well at reasonable temperatures is a major hurdle in protein crystallography, and many proteins refuse to yield such crystals. One such protein is the cysteine protease, cathepsin B, from Trypanosoma brucei (TbCatB), a promising drug target for the treatment of sleeping sickness, a fatal infectious disease that is fairly common in Africa. Using SFX scientists were able to obtain a three-dimensional native protein structure at 2.1 Å resolution. Besides the physical structure, the result allows physical chemists to understand a plausible chemical mechanism for inhibiting the enzyme. This new result, reported in Science, is an exciting milestone in molecular biophysics, human and animal health. More

Funding cut for SuperB collider kills project
Physics World
The Italian government has withdrawn its $325 million support for the SuperB collider. The loss of the Italian funding, which had been foreshadowed for at least a year, will likely kill the $1.3 billion project. Using the SuperB physicists would have collided electrons and positrons at 6.7 GeV where they would have decayed to B mesons. Physicists would have been able to study the subtle differences in how particles and their antiparticles decay and could help shed light on the mystery of why there is so much more matter than antimatter in the universe. This problem is actually being pursued by the LHCb collaboration at CERN; although while LHC collisions may result in greater B meson production, hadron collisions also produce more constituents and processes that make for greater challenges in precise isolation of B meson decay signals. B meson decay is also being pursued at Japan's SuperKEKB project and several other lepton colliders. Studying neutrino-less tau lepton decay, or "charged lepton flavor violation", was also a key scientific mission for the facility.More

Breakthrough in thermoacoustic imaging may make medical clinic appearance soon
Physics World
A technique that shoots microwaves into tissue and monitors the resulting acoustic waves may soon be common in clinical settings. Thermoacoustic imaging using microwaves can have higher contrast and is more penetrative than conceptually similar photoacoustic imaging, but the microwave method is too dangerous to use on humans. The breakthrough made by physicists in China and reported in Physical Review Letters comes from using short nanosecond pulses of microwaves. The nanosecond pulses reduce the wavelengths of the acoustic waves, and importantly they reduce the tissue's exposure to harmful microwaves. The technical challenge over the years has been to find ways to achieve short-pulsed microwave sources. With this new advance the researchers were able to achieve micron-level resolution and microwave exposure dosages 100 times lower than American safety standards. This result could make microwave-induced thermoacoustic tomography, which has the potential to image human bodies without using harmful X-rays or other ionizing radiation achievable within five years.More

Nanoparticles convert solar energy directly to steam
Laser Focus World
Physicists at Rice University's Laboratory for Nanophotonics have developed SiO2/Au and carbon-based nanoparticles that can convert solar energy directly into steam, even from icy cold water. The particles work at 24 percent efficiency, much better than current solar panels. The particle system described in the journal ACS Nano depends upon surface plasmon resonance where adsorption of radiation leads to collective oscillations of their delocalized conduction electrons. When excited on resonance, energy not reradiated through light scattering is dissipated through Landau (nonradiative) damping, resulting in a dramatic rise in temperature in the nanometer-scale vicinity of the particle surface. One of the effects of heating water at the surface of buoyant particles in this way is that there is no need to heat the bulk fluid, resulting in greater energy efficiency. While this nanoparticle system can be used to produce energy, the researchers have their eye more immediately on distillation and waste water treatment applications. More

Fiscal cliff update: Scientific R&D stands to lose 31,000 jobs and face a starvation diet
Discovery News
A study conducted for the Aerospace Industries Association suggests that 31,000 scientists stand to lose their jobs if sequestration takes place. (See 7 Policy Issues that Every Physicist Should Follow.) With one month to go before the automatic tax increases and spending cuts are set to occur there are few signs of compromise between the political parties. The disruptions to science enterprises could be deep, permanent, and extend far beyond American borders. Many scientific societies, including the National Society of Black Physicists and the American Physical Society have been calling upon Congress to act soon to avert the fiscal crisis. There are tools for individual members to communicate to their Representative and Senators what going over the so-called fiscal cliff would mean to scientific discovery, to overall economic growth, and to their personal job futures.More

National Society of Black Physicists jobs board postings
REU Student
Tenure Track Experimentalist Specializing in the Physics of Organic Electronic Materials
Vacuum Equipment Group Leader
Assistant Professor, Department of Radiology at Stanford University
Condensed Matter Theory Faculty Positions
Two-Year Visiting Assistant Professor of Physics
Tenure-track Position Applied Physics - Cornell University
Assistant Professor - University of Wisconsin-Eau Claire
Faculty Position in Computational Science — Virginia Tech College of Science
Faculty Positions in Interdisciplinary Science/Science Education Research
Faculty Positions in Science, Technology, and Innovation
Postdoctoral Research Position in Stellar Astrophysics at the Space Telescope Science Institute
Faculty Position in Experimental Astrophysics and Cosmology
Tenure-track Assistant Professor of Physics — Duquesne University
Tenure-Track Assistant Professor of Physics and Astronomy — Valparaiso University
Chair, Department of Physics
National Radio Astronomy Observatory Research Experience for Undergraduates
Renewable Energy REU at Colorado School of Mines
Lecturer (Physics), U.S. Coast Guard Academy
Experimental Particle Physics FacultyMore

Latest research from Physica Scripta
IOP Publishing
Searching for new physics through atomic, molecular and optical precision measurements

Nonlinear behavior of the surface waves between two magnetic fluid layers

Gamma-ray sensor based on an iron chloride tetraphenyl porphyrin/p-silicon heterojunction diode

Hidden assumptions in the derivation of the theorem of Bell

An alternative to the conventional micro-canonical ensembleMore

Latest research from New Astronomy
Photometric and spectroscopic observations of the F3+M3 eclipsing binary T-Lyr0-08070

Is the Sgr dSph a dark matter dominated system?

Study of the chemical evolution and spectral signatures of some interstellar precursor molecules of adenine, glycine & alanine

Extrasolar planet searches at the TUG: Test observations and capabilities

BVRI lightcurves of supernovae SN 2011fe in M101, SN 2012aw in M95, and SN 2012cg in NGC 4424

Implementation of an efficient logarithmic-Hamiltonian three-body codeMore