Phonon Heat Transfer...

Illustration of the quartz plates used to measure heat transfer. The coloured regions are electrodes used to position the plates. Courtesy: M Ghashami et al/Phys. Rev. Lett.)

Topics: Electrical Engineering, Experimental Physics, Thermodynamics

New insights into why heat transfer between objects is enhanced at very short separations have been gleaned by Keunhan Park and colleagues at the University of Utah and University of Pittsburgh in the US. The team made exquisitely precise measurements of how heat moves between two quartz plates that are positioned just 200 nm apart. They found that energy transfer is enhanced by about 45 times at tiny separations, which they ascribe to the coupling of surface photon polaritons across the gap between the plates.

Normally, the heat transfer between two objects at different temperatures can be approximated by assuming that the objects are “black bodies”. These are ideal entities that absorb all radiation falling on them and emit thermal radiation according to Planck’s law. Physicists have known for some time that this breaks down when objects get to within a few hundred nanometres of each other, where they exchange heat much faster than predicted by the black-body approximation. Indeed, this “near-field” enhancement has already been used in some technologies including heat extraction and thermophotovoltaic systems.

However, more widespread use of the enhancement has been hampered by a poor understanding of the effect – which is a result of significant experimental difficulties in measuring heat transfer between objects separated by just a few hundred nanometres. These challenges include controlling unwanted heat flow and achieving precise control over the orientation and separation of the two objects.

Surface phonon polaritons boost heat transfer, Hamish Johnston, Physics World

New Director...

Argonne physicist Kawtar Hafidi has been named the next director of the laboratory’s physics division. (Image by Wes Agresta/Argonne National Laboratory.)

Topics: Experimental Physics, Nuclear Physics, Research, Women in Science

Experimental nuclear physicist Kawtar Hafidi has been named the next director of Physics Division at the U.S. Department of Energy’s (DOE) Argonne National Laboratory.

Hafidi, who currently serves as the laboratory’s Associate Chief Scientist for Laboratory-Directed Research & Development (LDRD), has 17 years of experience in leading and conducting fundamental research at major accelerator facilities in the United States and Europe.  As Associate Chief Scientist, she established transparent processes aimed at supporting Argonne’s most important scientific priorities and assuring the greatest possible return on early scientific investment.

“Kawtar is an accomplished researcher with a great passion for science,” said Harry Weerts, Argonne Associate Laboratory Director for Physical Sciences and Engineering. “She brings to this role a strong vision for the future.”

As a researcher, Hafidi has focused on studying the structure of nucleons and nuclei in terms of their basic constituents, namely quarks and gluons, within the framework of the theory of strong interactions. Her work encompasses measurements of nuclear modification effects; three-dimensional imaging of nucleons and nuclei, the mechanisms of “vacuum” confinement and tests of charge symmetry violations.

Hafidi has also played a leading role in and received numerous awards for advocacy for increased diversity, both at Argonne and within the broader physics community. She is the author of more than 140 publications and has given more than 40 invited talks at international conferences, universities, and laboratories.

Argonne National Laboratory:
Kawtar Hafidi named director of Physics Division, Jared Sagoff

Fifth Force...

Credit: Avariel Falcon/Flickr, CC BY 2.0

Topics: Experimental Physics, Particle Physics, Radiation, Theoretical Physics

The Four (currently well-known) Forces: The Strong Force, the Electromagnetic Force, the Weak Force and Gravity. See: this link, which includes a brief primer on each and Feynman Diagrams on the strong and weak forces. Debate is going on now whether the new Force is evidence of Dark Energy, Dark Matter; a "Dark Photon" at 17 MeV, or what they refer to in the article as a "protophobic X (Greek letter Chi) boson." As with all reporting of scientific investigations, this is in its preliminary stages.

A laboratory experiment in Hungary has spotted an anomaly in radioactive decay that could be the signature of a previously unknown fifth fundamental force of nature, physicists say—if the finding holds up.

Attila Krasznahorkay at the Hungarian Academy of Sciences’s Institute for Nuclear Research in Debrecen, Hungary, and his colleagues reported their surprising result in 2015 on the arXiv preprint server, and this January in the journal Physical Review Letters. But the report – which posited the existence of a new, light boson only 34 times heavier than the electron—was largely overlooked.

Then, on April 25, a group of US theoretical physicists brought the finding to wider attention by publishing its own analysis of the result on arXiv. The theorists showed that the data didn’t conflict with any previous experiments—and concluded that it could be evidence for a fifth fundamental force. “We brought it out from relative obscurity,” says Jonathan Feng, at the University of California, Irvine, the lead author of the arXiv report.

Four days later, two of Feng's colleagues discussed the finding at a workshop at the SLAC National Accelerator Laboratory in Menlo Park, California. Researchers there were sceptical but excited about the idea, says Bogdan Wojtsekhowski, a physicist at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. “Many participants in the workshop are thinking about different ways to check it,” he says. Groups in Europe and the United States say that they should be able to confirm or rebut the Hungarian experimental results within about a year.

Scientific American:
Some theorists say a radioactive decay anomaly could imply a fundamental new force
Edwin Cartlidge

Two For The Price Of One...

Researchers have created a two-mode "Schrödinger's cat state" for the first time. (Courtesy: Michael S Helfenbein/Yale University)

Topics: Experimental Physics, Modern Physics, Quantum Computer, Quantum Mechanics, Schrödinger’s cat (s)

Schrödinger's cat now has a second box to play in, thanks to an international team of physicists that has created a two-mode "Schrödinger's cat state" for the first time. The experiment brings together two purely quantum properties, in that the "cat" (i.e. the photons) is simultaneously "alive and dead" (in a superposition of states) while also in two locations at once (the two boxes are entangled with one another).

The experiment is a step towards creating the larger and more sophisticated quantum states that are necessary to make quantum computing a reality. The team says that the work also demonstrates a two-logical-qubit system with in-built quantum error correction, making it a great resource for quantum metrology and quantum-communication networks.

Physics World: Schrödinger's cat lives and dies in two boxes at once
Tushna Commissariat

Magnetic Moment...

Illustration showing a proton (red) confined by magnetic-field lines (green) running down the centre of a Penning trap (yellow). (Courtesy: G Schneider, University of Mainz)

The most precise measurement ever of the proton's magnetic moment has been made by an international group of physicists. The new result – combined with a similar measurement planned for the proton's doppelganger, the antiproton – could help explain one of the deepest mysteries of physics – why the universe's matter seems to vastly outweigh its antimatter.

Every fundamental particle has a nearly identical antiparticle with opposite electric charge. Physicists' leading theories indicate that particles and their antiparticles were created in equal amounts during the Big Bang and should have annihilated each other long ago. But the universe is full of matter and lacks antimatter, suggesting that an undetected difference might exist between the two.

Physics World: Physicists lock in on proton's magnetic moment, Gabriel Popkin

RGDX...

A little something to do while vegging on the couch (nothing on the "boob tube" except COSMOS, really).

Controlling a lab from home

The Remote Control Glow Discharge (RGDX) is a plasma that you can control from the comfort of your browser. YOU have control of the entire experiment including the gas pressure inside the tube, the voltage produced by the power supply that makes the plasma, and the strength of an electromagnet surrounding the plasma. You can perform experiments from any computer anywhere in the world!

In 2002, we began developing plasma sources for educational purposes and one of our devices won 2nd place in the National Apparatus Competition sponsored by the American Association of Physics Teachers. In 2003, we began controlling our plasma sources by computer for a plasma exhibit in a science museum. The progression of this has led to remote control of a plasma from any location by anyone with an internet connection. This type of control could serve as an experimental component of an online physics class or for a school that typically does not have plasma physics equipment.

As with all other Science Education Department labs, the RGDX has been developed in large part by high school and undergraduate interns.

The Remote Glow Discharge Experiment was officially released to the public on 3/12/2014. The story can be found here.

PPPL: Remote Glow Discharge Experiment (RGDX)

PMC...

PMC stands for "Principle of Maximum Conformality." I'll let you explore it at the article's link.

I am 51 today. And physics is just as exciting to me as it was at 15...or 10...or 5...

"Throughout history, artists and poets, lovers and mystics, have known and written about the 'knowing' that comes from the loss of self - from the state of subjective fusion with the object of knowledge." Evelyn Fox Keller

"The state of feeling which makes one capable of such achievements is akin to that of the religious worshipper or of one who is in love." Albert Einstein

Three theoretical physicists have taken an important step toward eliminating theoretical ambiguities from the staggeringly complicated mathematics used to explore the interactions of quarks, the tiniest known bits of matter inside protons and neutrons, and gluons, the enigmatic particles responsible for keeping them trapped there. Simplifying these calculations can make them easier for other particle theorists to perform and lead to more accurate predictions for experimental particle physicists to test.

The theory describing those interactions is known as quantum chromodynamics (QCD), and is an important component of the Standard Model, the reigning theory of the interactions of subatomic particles.

"An important goal in high energy physics is to make predictions that are as precise as possible," said SLAC theoretical physicist Stan Brodsky. "This makes tests of QCD more rigorous. Most important, if QCD doesn't pass our experimental tests, it could reveal new physics beyond the Standard Model."

Stanford:
SLAC Theorist Helps Sharpen Tests of Fundamental Theory in High Energy Experiments

Multi-Pass Magnetometer...

Illustration showing the magnetic spins precessing with respect to the magnetic fields.
(Courtesy: J Shi/Princeton University)

An atomic magnetometer that can detect magnetic fields one hundred billion times smaller than the Earth's and does not require stringent shielding from the Earth's own field has been developed by an international group of researchers. The device is based on multi-pass atomic vapour cells and, the team says, can be used in various magnetic sensing applications such as measuring biological magnetic fields and land-mine clearance, as well as in geology and fundamental physics experiments.

Atomic magnetometers work by detecting how the energy levels of atoms are modified by an external magnetic field. This is the famous Zeeman effect – a quantum effect whereby the magnetic spin states in an atom split in the presence of an external magnetic field. This interaction between the atomic magnetic moment and external field is used to measure the field. This is normally done by using a pump laser to "polarize" the atoms by populating specific spin states, while a probe laser measures the spin precession, which is proportional to the magnetic field.

Physics World: Atomic magnetometer is most sensitive yet

Phaser Effect...

The theoretical foundations for the laser were established in 1917, when Einstein formulated the quantum theory of radiation, describing the absorption, spontaneous emission, and stimulated emission of electromagnetic radiation. Its realization stayed hidden for decades, however, before it emerged in the form of masers and lasers, which emit microwave and visible radiation, respectively. The range of emitted frequencies was soon broadened to cover wavelengths from the infrared to the x-ray range, and lasing was extrapolated beyond the realm of optics. Free-electron lasers, in which the active medium is a relativistic electron beam, helped cover extreme wavelength ranges and are now the basis for a new generation of experimental facilities for x-ray experiments. Atom lasers—emitting matter waves instead of photons—have also been demonstrated. Recently, the laser idea was extended to sound waves, leading to the conceptualization of the acoustic analog of a laser, which emits phonons (lattice vibrations) instead of photons. Now, writing in Physical Review Letters, Imran Mahboob at the NTT Basic Research Laboratories, Japan, and colleagues report on the experimental demonstration of a purely mechanical counterpart of a three-level laser scheme [1]. The device, excited by acoustic vibrations, amplifies sound waves through stimulated emission of phonons and acts as a phonon laser: a spectrally pure source of phonons with a frequency of around 1.7 megahertz (MHz).

What is the appeal of phonon lasers? One potential advantage is that their emission has smaller wavelength than that of photon lasers at the same frequency because the sound speed is much smaller than the speed of light. This could help improve the resolution of tomographic, ultrasound, and other imaging techniques. In analogy with their optical cousins, phonon lasers might deliver directional and coherent acoustic beams, which could be coupled to nanoscale mechanical engines or used in communication networks based on acoustic waves. But as the history of optical lasers suggests, most applications of future phonon lasers may be completely unexpected.

The Trekkie in me notes: from the phonon pump, the upper-to-intermediate level transition is called "Phaser Emission." Wonder if there's a stun setting?

American Physical Society: Lasers of Pure Sound

The Physics of Rembrandt...

Mock-up of Rembrandt's "An old man in military costume" with a portrait painted underneath the final work. Photo: Andrea Sartorius, © J. Paul Getty Trust (free for editorial use if credit is given)

A sophisticated X-ray technology is paving the way to uncover the secrets of a 380-year-old Rembrandt masterpiece. Underneath the Old Man in Military Costume, painted by the Dutch artist in the years 1630-31, previous investigations spotted another portrait which was only faintly distinguishable with all applied technologies. For years, art historians puzzled over the question of who is depicted on the repainted picture. 

Now, an international team of scientists has used a detailed mock-up to test different methods of looking beneath the original painting at DESYs X-ray source DORIS and at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) in the United States, as well as with a mobile X-ray scanner. The results are published as the cover story of the "Journal of Analytical Atomic Spectrometry" (JAAS) of the British Royal Society of Chemistry.

"Our experiments demonstrate a possibility of how to reveal much of the hidden picture," said first author Matthias Alfeld from the University of Antwerp (Belgium). "Compared to other techniques, the X-ray investigation we tested is currently the best method to look underneath the original painting."

Brookhaven National Labs: Mysterious Rembrandt

In Seven Days...

You Tube Channel: Space Lab

By JoVE...

If a photo is worth a thousand words, imagine the understanding that can be captured from 10 minutes at 30 frames per second. A scientific journal dedicated to video—a medium seldom seen in peer-reviewed publications—is finding out.

Increasingly, scientists include short video clips when they submit their manuscripts to a journal. But the Journal of Visualized Experiments—JoVE for short—is an online journal where video is the main medium rather than a supplement.

Each JoVE article consists of a short video segment that visually documents the required steps for performing an experiment. The video is supplemented by several paragraphs of peer-reviewed text. JoVE has developed a following in the life sciences, where being able to reproduce the results of an experiment in a timely fashion is a critical component to becoming a successful researcher.

They plan to offer an Applied Physics section July of 2012.

Technology Review: Science Journal Produces a Different Kind of Viral Video
Web site: JoVE.com

A Child Shall Lead Them...

...a fictional one, a dear literary memory so we will not become "smooth dinosaurs" (Octavia Butler, "Parable of the Sower"; "Parable of the Talents").





Web site: The B612 Foundation
The Little Prince: Asteroid B-612

Tadias...

Tadias is an online magazine for the Ethiopian-American community. It means "hi," "what's up," or "how are you?"

This is about a professor at my alma mater. The text and link will speak for itself:

"WASHINGTON, DC (TADIAS) – When Physicist Solomon Bililign was a young teacher imprisoned in Ethiopia during the “Red Terror” era, he never imagined that he would one day receive a Presidential Award in the United States.

Now a professor at North Carolina Agricultural and Technical State University, Dr. Bililign is one of nine individuals whom President Obama this week named recipients of the Presidential Award for Excellence in Science, Mathematics, and Engineering Mentoring. The honorees will receive their awards at a White House ceremony later this year. The award recognizes the role that mentoring plays in the academic and personal development of students studying science and engineering. According to the White House, candidates are nominated by colleagues, administrators, and students at their home institutions.

“Through their commitment to education and innovation, these individuals are playing a crucial role in the development of our 21st century workforce,” President Obama said. “Our nation owes them a debt of gratitude for helping ensure that America remains the global leader in science and engineering for years to come.”

Dr. Bililign said that success in science, engineering or math is not as glamorous as success in performing arts or sports in the U.S., but the economic competitiveness of the nation, depends on a solid foundation in the sciences. “Young people need to be encouraged, pushed, persuaded to do it,” he said. “Not for the money or fame but for the love of discovery and innovation. I believe every one has a gift, and a mentor’s role is to identify the gift and nurture it.”

TADIAS: Obama Honors Physicist Solomon Bililign With Presidential Award for Excellence