Providing concise yet thorough accounts of research papers from journals devoted to physics and the physical sciences. The department’s items are written and selected by Physics Today staff. After publication online, some of the department’s items appear later in the print issue.
With modest alterations, a perfect reflector of sound can become an excellent transmitter.
The information-carrying benefits of entanglement can survive in a lossy environment—even if the entanglement itself does not.
Electrolysis can extract metallic iron from iron ore, but only if the electrodes are up to it.
An analysis of two Moon rocks rules out one explanation for the puzzling longevity of our satellite's dipolar magnetic field.
Triggered by a laser pulse, a properly loaded nanogun could, at least in principle, fire a powerful stream of energetic protons.
Experiments with a spinning tank full of liquid metal may help explain why some planets' magnetic and rotational axes align and others' don't.
In a blazing wildfire, soil temperatures don’t necessarily increase with vegetative fuel and fire intensity.
The cosmos is just a little bit older and slower than we thought.
Researchers can now probe the brain neuron by neuron deep beneath the surface without cutting it apart.
The rise with energy of the positron-to-electron flux ratio has now been observed to flatten out.
A tiny explosion from a laser pulse comes in handy when you need a broadband signal.
A suite of techniques has laid bare the mysterious and physiologically debilitating structures.
Lab experiments could enable seismologists to map hot spots, plumes, and other structures in Earth's deep interior.
The curious consequence of relativistic quantum mechanics manifests as a short-lived bound electronic state.
A new study highlights the potential of low-orbiting satellites to observe earthquakes.
They're believed to accumulate and annihilate in the Sun's core.
An interdisciplinary collaboration tests whether birds can recognize a model’s reproduction of their own songs.
In the quest for cheap-yet-efficient solar cells, seeding a template bears fruit.
The short-lived knots untie themselves via an orderly sequence of reconnections.
High-speed dust triggers radio emission that threatens spacecraft's electrical systems.
The results from a new team, like those from three long-standing groups, show a slow rise over the past century.
Water is Earth's principal greenhouse molecule: It's responsible for well over half of the atmosphere's absorption of solar and terrestrial radiation.
A plane wave that interferes with its reflection can scatter off particles in a way that sends some of them upstream and others downstream.
The Fermi orbiter has revealed a long-sought signature of pion decay in the gamma-ray spectra of two supernova remnants.
Detecting the tiny magnetic field from a few thousand atomic nuclei is a first step toward imaging molecular structures directly.
A novel camera that can refocus images after they have been captured proves suitable for observing clouds of microparticles.
Precise radioisotope dating answers the objection that hundreds of thousands of years may have separated the meteor crash and the mass extinction.
Wireless communications networks unwittingly listen to the falling rain.
The thinning and breaking of blood-plasma filaments reveals the fluid’s viscoelasticity.
An array of semiconducting nanowires can absorb nearly as much light as a thin film but at lower cost.
The Milky Way's nearby twin is a good place to study galaxy formation.
Tinkering with an organism’s electric signaling can affect its growth in powerful and often surprising ways.
Observations by the Chandra X-Ray Observatory reveal the corkscrewed trail of particles emitted from the nearby Vela pulsar.
A ship-based measurement campaign reveals that mercury diffuses in and out of the South China Sea at rates that are high, seasonal, and troubling.
If a nanopore is sufficiently wide, folded DNA molecules can squeeze through. But where do the folds form?
A groundwater flow model reveals that merging tributaries have an affinity for the angle 2π/5.
Driven with an ultraintense and ultrashort light pulse, silica’s electrical conductivity can rise and fall by 18 orders of magnitude during a single optical cycle.
Organic LEDs are an emerging technology for electronic displays and lighting. And the materials that can be used to make them just got more diverse.
The building block of life as we know it, carbon forms in stars in a subtle and nontrivial way. Now the veil has been lifted on the structure of a fleeting resonance of that important nucleus.
A phase transition between hydrated salts is at the heart of a process that corrodes sculptures and buildings.
Intense laser bombardment creates an array of microcavities that help trap UV, visible, and IR light.
New evidence shows that a well-known phase of ice is even more complex than thought.
New experiments hint at what could be the lowest-density liquid ever found in nature.
A film of vanadium dioxide is just 1/65 the thickness of the wavelength it absorbs.
In a particle detector at a high-energy collider, anemic ionization would be their calling card.
In a new experiment, the complex rotational and vibrational motions of molecules are not a hindrance but a help.
A new design that peels off easily without damaging sensitive skin could be particularly valuable in neonatal care units.
Results from the Baryon Oscillation Spectroscopic Survey are consistent with standard cosmology and strengthen the case for dark energy.
Confocal microscopy reveals that Ebola virus exploits its host cells' own internal scaffolding to help it self-assemble and move.
New simulations provide insights into how a cooling effect known since the 1930s might be exploited.
New theory explains why trains of short laser pulses produce exceptionally uniform plasma shockwaves.
The first observations of highly electrified droplets in a rubbery polymer reveal the connection between fluid instabilities and the polymer’s dielectric breakdown.
New precautions in the repetition of an old experiment have wiped out its evidence for an exotic quantum phase of matter.
Micron-sized spheres offer a useful model for studying phase-transition dynamics.
As the relative motions of reactants become small enough, quantum effects manifest themselves.
Energy transitions in the three-body systems are intriguingly different from what theory calculates.
In the past three years, ice losses in West Antarctica have been offset by ice gains in East Antarctica.
The inherent disorder in microfluidic channels may provide an easy road to controllable on-chip lasers.
The two quantum opticians are honored "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems."
When submerged wires are exploded, they can transform the most common liquid on Earth into something far more exotic.
Coherent nonlinear Raman scattering can be harnessed to image molecular contrasts inside rocks.
A newly fabricated device can read and write information using the spin of an electron bound to a single atom.
Predicted half a century ago, time-reversal asymmetry in particle physics has only now been clearly demonstrated.
High-resolution atomic force microscopy can map out subtle variations in a molecule’s electronic structure.
Complex, nonlinear interactions between ocean waves can be frequently observed at beaches near low tide—and may affect tsunamis.
A recent experiment demonstrates that nonlinear optics can erase frequency differences in photons emitted by solid-state devices.
A new technique has the potential to separate healthy red blood cells from misshapen, diseased ones.
Made with a one-two punch of femtosecond laser processing and chemical etching, the optomechanical device is ripe for integration into larger systems.
A peculiar coexistence of synchrony and asynchrony has now been seen in experiments.
A simple gradient in channel depth can suppress the interfacial instability that always occurs when a less viscous fluid pushes against a more viscous one.
The Sun's brightness and surface magnetic activity rise and fall on an 11-year cycle.
The unidentified molecule reacts with sulfur dioxide, with implications for climate and human health.
Multiwavelength photoacoustics can detect and identify trace gases at parts-per-million concentrations.
New analyses of a mineral dug up in the Koryak Mountains of Russia reveal that it formed under extreme conditions during a meteorite collision.
By reducing ship traffic, the Great Recession enabled researchers to quantify an important source of low-frequency undersea noise.
High-quality data now enable a thorough testing of cloud simulations, which are getting closer to a passing grade.
The thin, flexible sensor can distinguish between a poke, a rub, and a twist.
Interaction with binary partners affects the life and death of the heaviest stars.
When a fluid is complex, a favorite buoyancy law breaks down.
Computer simulations boost confidence in a new medical technology that uses carbon nanotubes to generate x rays.
A new technique offers a stable train of laser pulses with a controllable amount of twist.
A single laser could replace an array of microphones as a useful tool for locating sounds in air.
It takes a sample of tree rings of unprecedented continuity and consistency to reveal a cosmic influence on Earth's climate.
With an appropriate electric field, viable and nonviable cells can be coaxed to migrate in opposing directions.
A defocusing technique reveals that particles can stick together in an otherwise pristine plasma “crystal.”
Further work will show whether it’s the last piece of the standard model or a sign of new physics.
Before an eruption, earthquakes and a rising sea floor sometimes herald the event. Detailed measurements reveal the dynamics of volcanism on a mid-ocean ridge.
The Kepler orbiter has unveiled two very different exoplanets in closely adjacent orbits.
After a decade of effort, astronomers have pinpointed the brightest submillimeter radiation source in the Hubble Deep Field.
Reflected thermal radiation sheds new light on painted surfaces.
A mathematical model suggests how pathogenic bacteria continue to thwart antibiotic treatment.
Physicists now have another tool for studying an important nuclear fuel.
An ocular puzzle is resolved in a new numerical simulation of human tears.
The layered composites conduct heat anisotropically, to counterintuitive effect.
By spraying quantum dots onto a graphene flake in a circuit, researchers have produced a phototransistor a billion times as sensitive as any prior graphene-based device.
The standard theory predicts that the ultramassive twins prefer to be born with the same handedness.
Single photons are a key ingredient in quantum information systems, but producing them on demand is difficult.
Nuclear magnetic resonance is a mature and powerful tool. But its theoretical underpinning has a significant omission.
The sensors can “smell” the difference between similar molecules.
Hieroglyphs on the walls of a small building predate well-studied codices by hundreds of years.
A device dubbed a sonic screwdriver helps corroborate a fundamental law of angular momentum.
Electrical conductance measurements reveal what may be a massless, chargeless, and spinless quasiparticle of zero energy.
PHYSICS UPDATE: Increasing CO2 preceded the great glacial retreat 18 000 years ago.
Two new studies revise key parameters used in radiometric dating.
It now seems unlikely that the bursts can be the only source of ultra-high-energy cosmic rays.
PHYSICS UPDATE: For quantum computation, qubits need to be isolated from their environment but connected to each other. For one kind of spin qubits, a means to achieve both has now been demonstrated.
We normally think of ultrasound as emanating from a medical device pressed against the body and of sonar as useful mainly for submarines and bats. But now humans can usefully combine the two in open air.
Once the tsunami of last March reached Hawaii, its wave energy took more than six hours to dissipate amid the islands' reefs, channels, and harbors.
A new model of capsid self-assembly treats biomolecules as balls and springs, with surprisingly good results.
A new lithographic method patterns UV-sensitive, water-absorbing polymers to produce complex, self-folding shapes.
If none of their three mixing angles is zero, neutrinos may be responsible for the cosmic shortage of antimatter.
Theory and experiment combine to examine an important ultrafast process in polyatomic molecules.
Different constituents play follow-the-leader during demagnetization, with an unexpected yet telling delay.
If spacetime is grainy, it may imprint a telltale signature on radiation interacting with a mechanical oscillator in a resonant cavity.
A modified commercial diode laser can generate intense flashes of coherent violet light on demand.
A new algorithm identifies the malignancy of thyroid nodules on the basis of the nodules' elasticity.
Conventional theory says you should be able to see through the tiny bubbles; new experiments say you can’t.
Researchers exploit the accumulation of polarized spin between two ferromagnetic metals to magnetically control the flow of heat across the interface.
How could a few volcanic winters chill the Northern Hemisphere for half a millennium?
The barrel opens only in the presence of certain target cells.
New research shows that anyone can start a rumor, but some people are better positioned to stifle them.
The currently accepted value for the planet’s rotation period is inconsistent with a new topographic map of its surface.
Icy clouds of carbon dioxide that float in the Martian atmosphere can form thanks to the cooling effect of gravity waves.
Its features are smaller than can be achieved with conventional photolithography.
An elusive but atmospherically important molecule yields to kinetic measurement for the first time.
The Milky Way seems to have more planets than stars
Quantum computing promises greater efficiency than classical computing. Quantum communication promises tamper-proof security. Combine the two and you get blind quantum computing.
The possibility was anticipated theoretically 16 years ago and could be used in applications as a semiconductor diagnostic.
The performance of diesel and rocket engines may be improved by exploiting size differences in droplets.
Anticyclonic winds in the Arctic are whipping up a vast reservoir of fresh water that could dissipate if the winds' rotation reverses.
Transported by specially designed microcapsules, the particles exit only when they arrive at a crack in a damaged material.
Locally heating a glass fiber is a surprisingly simple way to create and tune a microresonator.
There’s less and less room for particle theory’s long-sought capstone to hide.
Solar cells based on semiconductor nanocrystals can produce more than one electron–hole pair per incoming photon.
Periodic arrangements of crevasses produce a bandgap that can prevent flexing in the shelf interior.
A tabletop optical system can measure parts per quadrillion traces of the rare carbon isotope.
The photosynthetic system of an ocean-dwelling bacterium has been wired to allow electrons to quantum mechanically tunnel, rather than diffuse, between its reacting protein species.
As the world's oceans continue to absorb atmospheric CO2, the resulting changes could adversely affect coral reefs.
Silicon carbide, a material that’s already widely used for electronics, may also be suitable for quantum computation.
A recently developed technique for mass-producing nanoparticles shows its versatility.
Absorption spectra reveal intergalactic clouds with no elements that require a stellar furnace.
Using a new method, researchers have produced the lowest-density material ever made.
The ever-present oblique waves in a flapping flag are primarily responsible for the lift force that offsets the pull of gravity.
Two new algorithms automate a process that used to rely on expert assessments.
Inspired by the nanostructures in the wing of a male Papilio ulysses, researchers have made a silicon wafer that both repels water and strongly absorbs light.
Instead of looking at a surface pixel by pixel, a new microscope takes a more global view to achieve improved resolution.
The symmetry of a molecule affects its adsorption and movement atop an insulator.
The long-standing puzzle of how a hydrogen molecule can hold on to an extra electron for so long has finally been experimentally resolved.
Near IR lasers, fluorescently tagged nanoparticles, and tomographic reconstruction form the basis of a prototype device that could help surgeons locate and excise tumors.
A new spectroscopic design that alters the geometry of a key optical element advances the development of a portable noninvasive glucose monitor.
Bell’s inequalities are the quintessential test of a system’s nonlocality. But experiments show that the test can be fooled—if one ignores the fine print.
Sometimes, when the nozzle gets in the way, a plasma cutting torch goes haywire. A new study sheds some light on why.
As it sails across Earth during a solar eclipse, the lunar shadow creates a bow wave in the ionosphere like a moving boat does in water.
Sunlight, silicon, and readily available catalysts turn water into hydrogen and oxygen.
Researchers have outlined a recipe for fashioning subwavelength optical components from plasmonic antennas.
A subtle quantum interference effect controls how a cloud of atoms in an optical cavity responds to just a single photon.
Saul Perlmutter, Adam Riess, and Brian Schmidt are the recipients of this year's Nobel Prize in Physics for their momentous 1998 discovery.
By tinkering with light’s quantum fluctuations, researchers have improved the sensitivity of one of the interferometers that they hope will one day detect the elusive gravitational waves.
Photoemission techniques can be used to tease out the chiral orientation of metal-oxide substrates that selectively adsorb chiral molecules.
Evaporation of a trapped liquid can arrange nanoparticles into tunable patterns with long-range order.
New findings suggest that contrary to conventional wisdom, nanobubbles can host explosions.
A simple process for fabricating an antireflective coating may in time be applied to make more efficient solar cells.
A record-sensitive nuclear magnetic resonance experiment proves we still don’t know all there is to know about the most abundant liquid on the planet.
A sample of asteroid dust has clinched the link between them.
Embedded in a pair of shoes, circuits composed of a train of conductive droplets can generate a few watts of power—enough to charge a cell phone during a casual stroll.
Crumpled sheets of paper are a familiar form to most of us, but they still hold many secrets.
Few energy sources match the energy densities of hydrocarbon fuels. Fuel cells and lithium-air batteries tap into atmospheric oxygen to increase their efficiencies but the nanoscale dynamics are not well understood until now.
The orbiting PAMELA charged-particle spectrometer has revealed a significant population of antiprotons magnetically trapped in Earth’s inner Van Allen Belt.
Protein filaments made by some bacteria may bridge the gap between solid-state electronics and biological systems.
Using a single nonlinear optical element, researchers have entangled dozens of the comb’s optical modes.
Correlations in the concentrations of hundreds of different biomolecules could provide a way to diagnose obstructive nephropathy early and effectively.
Equations inspired by population-dynamics theory may help explain drizzles, downpours, and disappearing clouds.
Though a loudspeaker’s pressure field isn’t nearly strong enough to blow you backward, acoustic pressure can suspend millimeter-sized objects against the force of gravity.
Researchers combine optical trapping and frequency comb technology to control and measure the interaction of light with degenerate quantum gases.
A specialized leaf on the vine Marcgravia evenia uses acoustics to lure pollinating bats.
Short-range spin waves known as paramagnons are strong enough to hold electron pairs together in high-temperature superconducting cuprates.
The cooling and damping of a micromechanical oscillator’s motion to the ground state could pave the way to storage of quantum information and generation of entangled states in mechanical systems.
To properly extrapolate the past and future positions of Earth, one has to include not just the Sun, Moon, and other planets, but also asteroids. Still, such calculations can only go so far.
Every second, Earth expels 44 terajoules of energy into space. Much of that energy arises from the decay of radioactive isotopes but the remainder flows from an energy reservoir created billions of years ago, as our planet formed.
With new high-resolution data, researchers can determine that the background has been gravitationally distorted without knowing where the distorting foreground structures are.
Modeling the erosion history of a now-buried landscape reveals how the rock, which formed under water, was once lifted above sea level.
Perturbing biomolecules and then watching them relax may be a kind, gentle way to study protein folding in vivo.
A low-tech experiment demonstrates how time-reversal methods and an array of the cans can be used to beat the diffraction limit.
It hasn’t been found yet, but the limits are getting interesting.
A closer look at contact-induced static charge
The first appearance of electron neutrinos amidst an underground beam of muon neutrinos has been reported by Japan's T2K collaboration.
A new computer simulation sheds light on why the coastal city sometimes endures dangerous ozone pollution
If you chill helium-3 atoms enough, they settle into a single collective ground state, a Bose–Einstein condensate, that is a superfluid. Theorists can now characterize the vigorous turbulence that results from shaking or stirring in fermionic superfluids.
Researchers led by the University of Melbourne’s Lloyd Hollenberg have carried out magnetic resonance experiments on individual nanodiamonds placed inside human cells.
Researchers in France have figured out how to beat the Walker breakdown, a turbulence-triggering instability that slows down the switching of magnetic moments.
First-generation stars were not only very massive, as is generally thought, but also very rapidly spinning, with surface speeds as high as 800 km/s.
Albert Einstein’s description of Bose–Einstein condensation is based on a statistical argument, but experiences in the lab sometimes diverge from the textbook example.
Several noninvasive imaging techniques have been explored to detect skin cancer, but they can't distinguish between melanins. A nonlinear optical pump–probe technique may fix this problem.
Results of an experiment conceived around 1960 to test general relativity and launched in 2004 were announced at a NASA press conference earlier this month: Albert Einstein’s theory passed.