Astronomers have produced a highly detailed image of the Crab Nebula by combining data from telescopes spanning nearly the entire breadth of the electromagnetic spectrum.
Observatories Combine to Crack Open the Crab Nebula
Astronomers have produced a highly detailed image of the Crab Nebula by combining data from telescopes spanning nearly the entire breadth of the electromagnetic spectrum.
Ultrafast Reversal of the Ferroelectric Polarization
Author(s): R. Mankowsky, A. von Hoegen, M. Först, and A. Cavalleri
The ferroelectric polarization in LiNbO3 is transiently reversed with ultrashort optical pulses. The reversal is induced for both directions.
[Phys. Rev. Lett. 118, 197601] Published Wed May 10, 2017
Density-Functional Theory of the Fractional Quantum Hall Effect
Author(s): Jianyun Zhao, Manisha Thakurathi, Manish Jain, Diptiman Sen, and J. K. Jain
An alternative DFT approach on fractional quantum Hall systems uses composite fermions rather than electrons, thus sidestepping the problem of fractional orbital occupation.
[Phys. Rev. Lett. 118, 196802] Published Wed May 10, 2017
Ultrafast Reversal of the Ferroelectric Polarization
Author(s): R. Mankowsky, A. von Hoegen, M. Först, and A. Cavalleri
The ferroelectric polarization in LiNbO3 is transiently reversed with ultrashort optical pulses. The reversal is induced for both directions.
[Phys. Rev. Lett. 118, 197601] Published Wed May 10, 2017
Density-Functional Theory of the Fractional Quantum Hall Effect
Author(s): Jianyun Zhao, Manisha Thakurathi, Manish Jain, Diptiman Sen, and J. K. Jain
An alternative DFT approach on fractional quantum Hall systems uses composite fermions rather than electrons, thus sidestepping the problem of fractional orbital occupation.
[Phys. Rev. Lett. 118, 196802] Published Wed May 10, 2017
The Fermi Satellite detected its billionth gamma ray
The billionth time’s the charm.
Merging galaxies wrap their black holes in dusty shrouds
Only high-energy X-rays escape to tell astronomers about the accreting black holes within.
The wild wild worlds: a guide to the weirdest planets in the Milky Way
These are the most extreme planetary orbits in the universe.
International rescue
Technology image of the week: a rescue drone designed to save lives, developed by an ESA-based start-up in the Netherlands
NASA Delivers Detectors for ESA’s Euclid Spacecraft
Three detector systems for the Euclid mission have been delivered to Europe for the spacecraft’s infrared instrument.
Merging Galaxies Have Enshrouded Black Holes
Galaxies that are far along in the merging process are completely covered in a cocoon of gas and dust, a study using NuSTAR finds.
Merging Galaxies Have Enshrouded Black Holes
Galaxies that are far along in the merging process are completely covered in a cocoon of gas and dust, a study using NuSTAR finds.
NASA Delivers Detectors for ESA’s Euclid Spacecraft
Three detector systems for the Euclid mission have been delivered to Europe for the spacecraft’s infrared instrument.
Bloch Waves in Minimal Landau Gauge and the Infinite-Volume Limit of Lattice Gauge Theory
Author(s): Attilio Cucchieri and Tereza Mendes
Bloch’s theorem for electrons in crystalline solids is used in numerical simulations of gauge theories to extrapolate simulations on small number of lattice sites to infinite sites, improving the simulation efficiency.
[Phys. Rev. Lett. 118, 192002] Published Tue May 09, 2017
Possible Dark Matter Annihilation Signal in the AMS-02 Antiproton Data
Author(s): Ming-Yang Cui (崔明阳), Qiang Yuan (袁强), Yue-Lin Sming Tsai, and Yi-Zhong Fan (范一中)
Recently released data on cosmic-ray antiprotons may contain hints of dark matter, as revealed by two new analyses.
[Phys. Rev. Lett. 118, 191101] Published Tue May 09, 2017
Novel Dark Matter Constraints from Antiprotons in Light of AMS-02
Author(s): Alessandro Cuoco, Michael Krämer, and Michael Korsmeier
Recently released data on cosmic-ray antiprotons may contain hints of dark matter, as revealed by two new analyses.
[Phys. Rev. Lett. 118, 191102] Published Tue May 09, 2017
Velocity Fluctuations in Sedimenting Brownian Particles
Author(s): Johannes Möller and Theyencheri Narayanan
During the early stages of sedimentation, synchrotron x-ray studies show that Brownian particles flow similarly to non-Brownian suspensions before Brownian motion takes over.
[Phys. Rev. Lett. 118, 198001] Published Tue May 09, 2017
Bloch Waves in Minimal Landau Gauge and the Infinite-Volume Limit of Lattice Gauge Theory
Author(s): Attilio Cucchieri and Tereza Mendes
Bloch’s theorem for electrons in crystalline solids is used in numerical simulations of gauge theories to extrapolate simulations on small number of lattice sites to infinite sites, improving the simulation efficiency.
[Phys. Rev. Lett. 118, 192002] Published Tue May 09, 2017
Possible Dark Matter Annihilation Signal in the AMS-02 Antiproton Data
Author(s): Ming-Yang Cui (崔明阳), Qiang Yuan (袁强), Yue-Lin Sming Tsai, and Yi-Zhong Fan (范一中)
Recently released data on cosmic-ray antiprotons may contain hints of dark matter, as revealed by two new analyses.
[Phys. Rev. Lett. 118, 191101] Published Tue May 09, 2017
Novel Dark Matter Constraints from Antiprotons in Light of AMS-02
Author(s): Alessandro Cuoco, Michael Krämer, and Michael Korsmeier
Recently released data on cosmic-ray antiprotons may contain hints of dark matter, as revealed by two new analyses.
[Phys. Rev. Lett. 118, 191102] Published Tue May 09, 2017
Velocity Fluctuations in Sedimenting Brownian Particles
Author(s): Johannes Möller and Theyencheri Narayanan
During the early stages of sedimentation, synchrotron x-ray studies show that Brownian particles flow similarly to non-Brownian suspensions before Brownian motion takes over.
[Phys. Rev. Lett. 118, 198001] Published Tue May 09, 2017
Comet 67P is making its own oxygen gas
A Caltech chemical engineering professor used his laboratory research to explain 67P’s oxygen atmosphere.
This Chinese telescope team is making a 7,000 mile journey to the eclipse
An optical telescope built by the Chinese researchers starts its journey to 2017’s Great American Solar Eclipse
Future EO
Follow the “Paradigm shifts and future prospects in Earth observation” seminar via live webstream on 11 May at 09:00 CEST
Alaska Tundra Source of Early-Winter Carbon Emissions
Warmer temperatures and thawing soils may be driving an increase in emissions of carbon dioxide from Alaskan tundra to the atmosphere, particularly during the early winter.
Alaska Tundra Source of Early-Winter Carbon Emissions
Warmer temperatures and thawing soils may be driving an increase in emissions of carbon dioxide from Alaskan tundra to the atmosphere, particularly during the early winter.
Study of J/ψ Production in Jets
Author(s): R. Aaij et al. (LHCb Collaboration)
A study of J/ψ production in jets reveals the weaknesses of a widely used method of simulating high-energy particle collisions.
[Phys. Rev. Lett. 118, 192001] Published Mon May 08, 2017
Study of J/ψ Production in Jets
Author(s): R. Aaij et al. (LHCb Collaboration)
A study of J/ψ production in jets reveals the weaknesses of a widely used method of simulating high-energy particle collisions.
[Phys. Rev. Lett. 118, 192001] Published Mon May 08, 2017
Not just ‘revenge porn’ – image-based abuse hits 1 in 5 Australians
The first comprehensive research on “revenge porn” has revealed the mass scale of victimisation across Australia, with one in five people suffering image-based abuse, according to a study by Monash University and RMIT University.
I spy…
Space Science Image of the Week: Looking into the Cheops telescope that will study planets circling other stars
I spy…
Space Science Image of the Week: Looking into the Cheops telescope that will study planets circling other stars
Investigation of the rolling motion of a hollow cylinder using a smartphone’s digital compass
This study used a smartphone’s digital compass to observe the rolling motion of a hollow cylinder on
an inclined plane. The smartphone (an iPhone 4s) was attached to the end of one side of a hollow
cylinder to record the experimental data using the…
Introducing 12 year-olds to elementary particles
We present a new learning unit, which introduces 12 year-olds to the subatomic structure of matter.
The learning unit was iteratively developed as a design-based research project using the technique
of probing acceptance. We give a brief overview of …
Activities to investigate wavelength-shifting optical fibers
Understanding principles and operation of optical fibers is important for students of physics due to
increased applications of fiber optics in today’s technological world. In an effort to devise new
activities to study such fibers, we obtained samp…
Eye-tracking of visual attention in web-based assessment using the Force Concept Inventory
This study used eye-tracking technology to investigate students’ visual attention while taking the
Force Concept Inventory (FCI) in a web-based interface. Eighty nine university students were
randomly selected into a pre-test group and a post-test …
Determining the speed of sound in the air by sound wave interference
Mechanical waves propagate through material media. Sound is an example of a mechanical wave. In
fluids like air, sound waves propagate through successive longitudinal perturbations of compression
and decompression. Audible sound frequencies for human…
A mean field approach to the Ising chain in a transverse magnetic field
We evaluate a mean field method to describe the properties of the ground state of the Ising chain in
a transverse magnetic field. Specifically, a method of the Bethe–Peierls type is used by solving
spin blocks with a self-consistency condition at t…
Investigating and improving student understanding of the expectation values of observables in quantum mechanics
The expectation value of an observable is an important concept in quantum mechanics since
measurement outcomes are, in general, probabilistic and we only have information about the
probability distribution of measurement outcomes in a given quantum s…
Microscopic and probabilistic approach to thermal steady state based on a dice and coin toy model
In this article we present an educational approach to thermal equilibrium which was tested on a
group of 13 undergraduate students at the University of Trento. The approach is based on a
stochastic toy model, in which bodies in thermal contact are re…
Scaling, scattering, and blackbody radiation in classical physics
Here we discuss blackbody radiation within the context of classical theory. We note that
nonrelativistic classical mechanics and relativistic classical electrodynamics have contrasting
scaling symmetries which influence the scattering of radiation. A…
Eye-tracking of visual attention in web-based assessment using the Force Concept Inventory
This study used eye-tracking technology to investigate students’ visual attention while taking the
Force Concept Inventory (FCI) in a web-based interface. Eighty nine university students were
randomly selected into a pre-test group and a post-test …
Determining the speed of sound in the air by sound wave interference
Mechanical waves propagate through material media. Sound is an example of a mechanical wave. In
fluids like air, sound waves propagate through successive longitudinal perturbations of compression
and decompression. Audible sound frequencies for human…
A mean field approach to the Ising chain in a transverse magnetic field
We evaluate a mean field method to describe the properties of the ground state of the Ising chain in
a transverse magnetic field. Specifically, a method of the Bethe–Peierls type is used by solving
spin blocks with a self-consistency condition at t…
Investigating and improving student understanding of the expectation values of observables in quantum mechanics
The expectation value of an observable is an important concept in quantum mechanics since
measurement outcomes are, in general, probabilistic and we only have information about the
probability distribution of measurement outcomes in a given quantum s…
Microscopic and probabilistic approach to thermal steady state based on a dice and coin toy model
In this article we present an educational approach to thermal equilibrium which was tested on a
group of 13 undergraduate students at the University of Trento. The approach is based on a
stochastic toy model, in which bodies in thermal contact are re…
Scaling, scattering, and blackbody radiation in classical physics
Here we discuss blackbody radiation within the context of classical theory. We note that
nonrelativistic classical mechanics and relativistic classical electrodynamics have contrasting
scaling symmetries which influence the scattering of radiation. A…
Investigation of the rolling motion of a hollow cylinder using a smartphone’s digital compass
This study used a smartphone’s digital compass to observe the rolling motion of a hollow cylinder on
an inclined plane. The smartphone (an iPhone 4s) was attached to the end of one side of a hollow
cylinder to record the experimental data using the…
Introducing 12 year-olds to elementary particles
We present a new learning unit, which introduces 12 year-olds to the subatomic structure of matter.
The learning unit was iteratively developed as a design-based research project using the technique
of probing acceptance. We give a brief overview of …
Activities to investigate wavelength-shifting optical fibers
Understanding principles and operation of optical fibers is important for students of physics due to
increased applications of fiber optics in today’s technological world. In an effort to devise new
activities to study such fibers, we obtained samp…
Is Climate Changing Cloud Heights? Too Soon to Say
With 10 years of MISR satellite data, scientists suspected global cloud heights might be getting lower. With 15 years of data, they’ve found it’s too early to say for sure.
Is Climate Changing Cloud Heights? Too Soon to Say
With 10 years of MISR satellite data, scientists suspected global cloud heights might be getting lower. With 15 years of data, they’ve found it’s too early to say for sure.
Holography of Wi-fi Radiation
Author(s): Philipp M. Holl and Friedemann Reinhard
The Wi-Fi signals that provide internet access can also produce images of the transmitter’s 3D surroundings, even through walls.
[Phys. Rev. Lett. 118, 183901] Published Fri May 05, 2017
Transition from Collisional to Collisionless Regimes in Interpenetrating Plasma Flows on the National Ignition Facility
Author(s): J. S. Ross et al.
A transition from a Coulomb-collision-dominated regime to a collisionless-collective-scattering regime is observed at the NIF in plasmas with high Mach numbers.
[Phys. Rev. Lett. 118, 185003] Published Fri May 05, 2017
Holography of Wi-fi Radiation
Author(s): Philipp M. Holl and Friedemann Reinhard
The Wi-Fi signals that provide internet access can also produce images of the transmitter’s 3D surroundings, even through walls.
[Phys. Rev. Lett. 118, 183901] Published Fri May 05, 2017
Transition from Collisional to Collisionless Regimes in Interpenetrating Plasma Flows on the National Ignition Facility
Author(s): J. S. Ross et al.
A transition from a Coulomb-collision-dominated regime to a collisionless-collective-scattering regime is observed at the NIF in plasmas with high Mach numbers.
[Phys. Rev. Lett. 118, 185003] Published Fri May 05, 2017
Week In Images
Our week through the lens: 1-5 May 2017
Week In Images
Our week through the lens: 1-5 May 2017
Amsterdam
Earth observation image of the week: a Sentinel-2 image over part of the western Netherlands, also featured on the Earth from Space video programme
Reply to Comment on ‘A note on heat reservoirs and the like’
We show that the claim that our definition of reversibility for processes in a system is incorrect
is based on erroneous or irrelevant reasoning.
Comment on ‘A note on heat reservoirs and the like’
This comment addresses some points in the paper by de los Santos and López-Lacomba (2013 Eur. J.
Phys. 34 [http://https://doi.org/10.1088/0143-0807/34/3/659] 659 ). More specifically, we clarify
the use of the Clausius relation and argue that the pr…
Driven damped harmonic oscillator resonance with an Arduino
In this paper we propose a simple experimental apparatus that can be used to show quantitative and
qualitative results of resonance in a driven damped harmonic oscillator. The driven oscillation is
made by a servo motor, and the oscillation amplitude…
Free oscilloscope web app using a computer mic, built-in sound library, or your own files
We have developed an online oscilloscope program which allows users to see waveforms by utilizing
their computer microphones, selecting from our library of over 30 audio files, and opening any *.mp3
or *.wav file on their computers. The oscilloscope …
Discovering the gas laws and understanding the kinetic theory of gases with an iPad app
Carrying out classroom experiments that demonstrate Boyle’s law and Gay-Lussac’s law can be
challenging. Even if we are able to conduct classroom experiments using pressure gauges and
syringes, the results of these experiments do little to illumi…
A teaching-learning sequence about weather map reading
In this paper a teaching-learning sequence (TLS) introducing pre-service elementary teachers (PET)
to weather map reading, with emphasis on wind assignment, is presented. The TLS includes activities
about recognition of wind symbols, assignment of wi…
Three-in-one resonance tube for harmonic series sound wave experiments
In this study we constructed a special three-in-one resonance tube for a harmonic series sound waves
experiment. It is designed for three different experiments: both-open-end, one-closed-end and
both-closed-end tubes. The resonance tube consists of a…
Reply to Comment on ‘A note on heat reservoirs and the like’
We show that the claim that our definition of reversibility for processes in a system is incorrect
is based on erroneous or irrelevant reasoning.
Comment on ‘A note on heat reservoirs and the like’
This comment addresses some points in the paper by de los Santos and López-Lacomba (2013 Eur. J.
Phys. 34 [http://https://doi.org/10.1088/0143-0807/34/3/659] 659 ). More specifically, we clarify
the use of the Clausius relation and argue that the pr…
Driven damped harmonic oscillator resonance with an Arduino
In this paper we propose a simple experimental apparatus that can be used to show quantitative and
qualitative results of resonance in a driven damped harmonic oscillator. The driven oscillation is
made by a servo motor, and the oscillation amplitude…
Free oscilloscope web app using a computer mic, built-in sound library, or your own files
We have developed an online oscilloscope program which allows users to see waveforms by utilizing
their computer microphones, selecting from our library of over 30 audio files, and opening any *.mp3
or *.wav file on their computers. The oscilloscope …
Discovering the gas laws and understanding the kinetic theory of gases with an iPad app
Carrying out classroom experiments that demonstrate Boyle’s law and Gay-Lussac’s law can be
challenging. Even if we are able to conduct classroom experiments using pressure gauges and
syringes, the results of these experiments do little to illumi…
A teaching-learning sequence about weather map reading
In this paper a teaching-learning sequence (TLS) introducing pre-service elementary teachers (PET)
to weather map reading, with emphasis on wind assignment, is presented. The TLS includes activities
about recognition of wind symbols, assignment of wi…
Three-in-one resonance tube for harmonic series sound wave experiments
In this study we constructed a special three-in-one resonance tube for a harmonic series sound waves
experiment. It is designed for three different experiments: both-open-end, one-closed-end and
both-closed-end tubes. The resonance tube consists of a…
Ariane 5’s second liftoff this year
Ariane 5 has delivered two telecom satellites, SGDC and Koreasat-7, into their planned orbits.
Ariane 5’s second liftoff this year
Ariane 5 has delivered two telecom satellites, SGDC and Koreasat-7, into their planned orbits.
NASA Rover Samples Active Linear Dune on Mars
As it drives uphill from a band of rippled sand dunes, NASA’s Curiosity Mars rover is toting a fistful of dark sand for onboard analysis that will complete its investigation of those dunes.
Dawn Mission Honored by RNASA Foundation
Members of NASA’s Dawn mission were honored with awards from the Rotary National Award for Space Achievement (RNASA) Foundation at a banquet in Houston on April 28, 2017.
Dawn Mission Honored by RNASA Foundation
Members of NASA’s Dawn mission were honored with awards from the Rotary National Award for Space Achievement (RNASA) Foundation at a banquet in Houston on April 28, 2017.
NASA Rover Samples Active Linear Dune on Mars
As it drives uphill from a band of rippled sand dunes, NASA’s Curiosity Mars rover is toting a fistful of dark sand for onboard analysis that will complete its investigation of those dunes.
AIRS: 15 Years of Seeing What’s in the Air
The 15-year-old AIRS instrument is an asset for weather forecasters and climate scientists worldwide, providing detailed 3-D maps of the atmosphere’s weather-making layer.
AIRS: 15 Years of Seeing What’s in the Air
The 15-year-old AIRS instrument is an asset for weather forecasters and climate scientists worldwide, providing detailed 3-D maps of the atmosphere’s weather-making layer.
New Tool May Assist US Regional Sea Level Planning
A new tool may help planners and decision makers identify key regions of the U.S. coastline that are vulnerable to regional sea level changes on 10- to 20-year timescales.
New Tool May Assist US Regional Sea Level Planning
A new tool may help planners and decision makers identify key regions of the U.S. coastline that are vulnerable to regional sea level changes on 10- to 20-year timescales.
Õpilaste teadustööde riiklikul konkursil
Õpilaste teadustööde riiklikul konkursil võitis Eesti Füüsika Seltsi eripreemia Hartvig Tooming Tallinna Prantsuse Lütseumist töö “Tumeenergia mõju galaktikaparvede massi määramisele viriaalmeetodiga” eest. Kosmoloogia on hetkel üks Eesti eesrindlikumatest teadussuundadest. Autor tegi põhjaliku töö ning demonstreeris keeruliste materjalidega tegelemise ja analüüsimise oskust. Kuigi töö teema on võrdelmisi raske, suutis Hartvig selle tulemusi tõlgendada ning seda ka […]
Listening for Cassini
Operations image of the week: ESA’s deep-space dish antennas in Argentina and Australia get ready for science with the international Cassini orbiter
Matter-Wave Tractor Beams
Author(s): Alexey A. Gorlach, Maxim A. Gorlach, Andrei V. Lavrinenko, and Andrey NovitskyTheory shows that the quantum-mechanical wave of a beam of particles can exert a pulling force on a small particle, just as other waves do.[Phys. Rev. Lett. 118, 1…
Quantum Hall Spin Diode
Author(s): J. P. Eisenstein, L. N. Pfeiffer, and K. W. West
A bilayer two-dimensional electron system, known for its use as a magnetic tunnel junction, can also behave as a nearly ideal spin diode when the spins are antiparallel.
[Phys. Rev. Lett. 118, 186801] Published Thu May 04, 2017
Experimental Determination of Dynamical Lee-Yang Zeros
Author(s): Kay Brandner, Ville F. Maisi, Jukka P. Pekola, Juan P. Garrahan, and Christian Flindt
Lee-Yang zeros–complex singularities of the free energy in systems of finite size–are experimentally determined for the first time.
[Phys. Rev. Lett. 118, 180601] Published Thu May 04, 2017
Matter-Wave Tractor Beams
Author(s): Alexey A. Gorlach, Maxim A. Gorlach, Andrei V. Lavrinenko, and Andrey NovitskyTheory shows that the quantum-mechanical wave of a beam of particles can exert a pulling force on a small particle, just as other waves do.[Phys. Rev. Lett. 118, 1…
Quantum Hall Spin Diode
Author(s): J. P. Eisenstein, L. N. Pfeiffer, and K. W. West
A bilayer two-dimensional electron system, known for its use as a magnetic tunnel junction, can also behave as a nearly ideal spin diode when the spins are antiparallel.
[Phys. Rev. Lett. 118, 186801] Published Thu May 04, 2017
Experimental Determination of Dynamical Lee-Yang Zeros
Author(s): Kay Brandner, Ville F. Maisi, Jukka P. Pekola, Juan P. Garrahan, and Christian Flindt
Lee-Yang zeros–complex singularities of the free energy in systems of finite size–are experimentally determined for the first time.
[Phys. Rev. Lett. 118, 180601] Published Thu May 04, 2017
Earth from Space
Join us Friday, 05 May, at 10:00 CEST for the ‘Earth from Space’ video programme
Hubble images the distant universe through a cosmic lens
This galaxy cluster offers a peek at objects in the early universe sitting behind it.
Scientists found a wave of ultra hot gas bigger than the Milky Way
Big waves keep on rolling. Perseus Galaxy Cluster keep on burning.
Test site for ESA-backed airbreathing engine
Work began today on building the UK’s latest rocket engine test facility, designed for firing the engine core of the ESA-backed SABRE propulsion system within three years.
Test site for ESA-backed airbreathing engine
Work began today on building the UK’s latest rocket engine test facility, designed for firing the engine core of the ESA-backed SABRE propulsion system within three years.
New Movie Shows Cassini’s First Dive over Saturn
A new movie sequence of images from NASA’s Cassini shows the view as the spacecraft swooped over Saturn during its first Grand Finale dive on April 26.
New Movie Shows Cassini’s First Dive over Saturn
A new movie sequence of images from NASA’s Cassini shows the view as the spacecraft swooped over Saturn during its first Grand Finale dive on April 26.
Facile Anhydrous Proton Transport on Hydroxyl Functionalized Graphane
Author(s): Abhishek Bagusetty, Pabitra Choudhury, Wisssam A. Saidi, Bridget Derksen, Elizabeth Gatto, and J. Karl JohnsonA proposed graphene-based material could offer speedy transport of protons without the need for water.[Phys. Rev. Lett. 118, 186101…
Facile Anhydrous Proton Transport on Hydroxyl Functionalized Graphane
Author(s): Abhishek Bagusetty, Pabitra Choudhury, Wisssam A. Saidi, Bridget Derksen, Elizabeth Gatto, and J. Karl JohnsonA proposed graphene-based material could offer speedy transport of protons without the need for water.[Phys. Rev. Lett. 118, 186101…