ISRO went for the stars. Now it’s being celebrated on the 2000 rupee banknote.
Astronomers look a spiral galaxy in the eye
The massive eye in the middle IC 2613 is the product of a rare cosmic tidal wave
Four easy routes to the Lorentz transformations: addendum to ‘Lorentz transformations and the wave equation’
In this paper I briefly discuss and compare four easy derivations of the Lorentz transformations.
Two of these derivations assume the invariance of the Minkowski spacetime interval in inertial
frames and the other two assume the invariance of the d?…
Comment on ‘Lorentz transformations and the wave equation’
In this comment we make some clarifications with respect to certain asumptions and demands required
by Ricardo Heras in his paper entitled ‘Lorentz transformations and the wave equation’ (2016 Eur. J.
Phys. 37 [http://https://doi.org/10.1088/0143…
A laboratory activity for teaching natural radioactivity
This paper presents an educational approach for teaching natural radioactivity using commercial
granite samples. A laboratory activity focusing on the topic of natural radioactivity is designed to
develop the knowledge and understanding of undergradu…
Comment on ‘Lorentz transformations and the wave equation’
In this comment we make some clarifications with respect to certain asumptions and demands required
by Ricardo Heras in his paper entitled ‘Lorentz transformations and the wave equation’ (2016 Eur. J.
Phys. 37 [http://https://doi.org/10.1088/0143…
A laboratory activity for teaching natural radioactivity
This paper presents an educational approach for teaching natural radioactivity using commercial
granite samples. A laboratory activity focusing on the topic of natural radioactivity is designed to
develop the knowledge and understanding of undergradu…
Four easy routes to the Lorentz transformations: addendum to ‘Lorentz transformations and the wave equation’
In this paper I briefly discuss and compare four easy derivations of the Lorentz transformations.
Two of these derivations assume the invariance of the Minkowski spacetime interval in inertial
frames and the other two assume the invariance of the d?…
Evidence for Marginal Stability in Emulsions
Author(s): Jie Lin, Ivane Jorjadze, Lea-Laetitia Pontani, Matthieu Wyart, and Jasna BrujicConfocal microscopy experiments reveal the effect of pressure on the spectrum of the vibrational modes for compressed emulsions. The observed scaling behavior in …
Quantum Entanglement as a Diagnostic of Phase Transitions in Disordered Fractional Quantum Hall Liquids
Author(s): Zhao Liu and R. N. Bhatt
Quantum entanglement could be used as a diagnostic for spotting disorder-driven topological phase transitions in fractional quantum Hall liquids.
[Phys. Rev. Lett. 117, 206801] Published Tue Nov 08, 2016
Smooth Horizonless Geometries Deep Inside the Black-Hole Regime
Author(s): Iosif Bena, Stefano Giusto, Emil J. Martinec, Rodolfo Russo, Masaki Shigemori, David Turton, and Nicholas P. WarnerA novel class of horizonless supersymmetric black holes in five dimensions and their dual field theory descriptions are constr…
Synthesis of Freestanding Graphene on SiC by a Rapid-Cooling Technique
Author(s): Jianfeng Bao, Wataru Norimatsu, Hiroshi Iwata, Keita Matsuda, Takahiro Ito, and Michiko KusunokiThe addition of a rapid-cooling step to the epitaxial growth of graphene on silicon carbide can yield higher-quality graphene sheets.[Phys. Rev. …
Smooth Horizonless Geometries Deep Inside the Black-Hole Regime
Author(s): Iosif Bena, Stefano Giusto, Emil J. Martinec, Rodolfo Russo, Masaki Shigemori, David Turton, and Nicholas P. WarnerA novel class of horizonless supersymmetric black holes in five dimensions and their dual field theory descriptions are constr…
Evidence for Marginal Stability in Emulsions
Author(s): Jie Lin, Ivane Jorjadze, Lea-Laetitia Pontani, Matthieu Wyart, and Jasna BrujicConfocal microscopy experiments reveal the effect of pressure on the spectrum of the vibrational modes for compressed emulsions. The observed scaling behavior in …
Synthesis of Freestanding Graphene on SiC by a Rapid-Cooling Technique
Author(s): Jianfeng Bao, Wataru Norimatsu, Hiroshi Iwata, Keita Matsuda, Takahiro Ito, and Michiko KusunokiThe addition of a rapid-cooling step to the epitaxial growth of graphene on silicon carbide can yield higher-quality graphene sheets.[Phys. Rev. …
Quantum Entanglement as a Diagnostic of Phase Transitions in Disordered Fractional Quantum Hall Liquids
Author(s): Zhao Liu and R. N. Bhatt
Quantum entanglement could be used as a diagnostic for spotting disorder-driven topological phase transitions in fractional quantum Hall liquids.
[Phys. Rev. Lett. 117, 206801] Published Tue Nov 08, 2016
Flying the fantastic four
This month, a single Ariane 5 rocket is set to propel four Galileo satellites into orbit for the navigation constellation’s first-ever quadruple launch. Mission controllers are training intensively for the complex space delivery.
Cassini video shows methane clouds develop and fade over Titan
The time-lapse movie may answer some questions about Titan’s cloud dynamics
Cassini video shows methane clouds develop and fade over Titan
The time-lapse movie may answer some questions about Titan’s cloud dynamics
Should future Mars missions include hunts for life?
Forty years after Viking, arguments remain about whether it found life
Galileo system status
A video update on the 17 November Ariane 5 launch of four Galileo satellites, to bring the total number of European navigation satellites in orbit from 14 to 18
Dynamical interactions between two uniformly magnetized spheres
Studies of the two-dimensional motion of a magnet sphere in the presence of a second, fixed sphere
provide a convenient venue for exploring magnet–magnet interactions, inertia, friction, and rich
nonlinear dynamical behavior. These studies exploit …
Dynamical interactions between two uniformly magnetized spheres
Studies of the two-dimensional motion of a magnet sphere in the presence of a second, fixed sphere
provide a convenient venue for exploring magnet–magnet interactions, inertia, friction, and rich
nonlinear dynamical behavior. These studies exploit …
NASA Small Satellites Will Take a Fresh Look at Earth
NASA is launching six next-generation, Earth-observing small satellite missions to demonstrate innovative approaches for studying our changing planet.
A Box of ‘Black Magic’ to Study Earth from Space
CubeSats are challenging JPL engineers to build next-gen antennas.
A Box of ‘Black Magic’ to Study Earth from Space
CubeSats are challenging JPL engineers to build next-gen antennas.
NASA Small Satellites Will Take a Fresh Look at Earth
NASA is launching six next-generation, Earth-observing small satellite missions to demonstrate innovative approaches for studying our changing planet.
Large Cross-Phase Modulations at the Few-Photon Level
Author(s): Zi-Yu Liu, Yi-Hsin Chen, Yen-Chun Chen, Hsiang-Yu Lo, Pin-Ju Tsai, Ite A. Yu, Ying-Cheng Chen, and Yong-Fan ChenMicroscopic clouds of cold atoms can mediate interactions between weak pulses of light at the level required for quantum logic wi…
Large Cross-Phase Modulations at the Few-Photon Level
Author(s): Zi-Yu Liu, Yi-Hsin Chen, Yen-Chun Chen, Hsiang-Yu Lo, Pin-Ju Tsai, Ite A. Yu, Ying-Cheng Chen, and Yong-Fan ChenMicroscopic clouds of cold atoms can mediate interactions between weak pulses of light at the level required for quantum logic wi…
The exoplanet closest to home has a new observer
The Parkes telescope is studying Proxima Centauri b to see if there’s life there
Little Gem in jewel tones
Space Science Image of the Week: Planetary nebula shows off its beautiful turquoise and rose quartz tones in new Hubble image
Explore Morocco
As the COP22 climate change summit begins in Marrakesh, explore Morocco with this mosaic from Sentinel-2. Experience Sentinel-2’s high-resolution imaging capabilities directly in your browser
An elementary approach to the gravitational Doppler shift
In college physics courses, treatment of the Doppler effect is usually done far from the first
introduction to kinematics. This paper aims to apply a graphical treatment to describe the
gravitational redshift, by considering the Doppler effect in two…
A note on the electric and magnetic susceptibilities
The linear electric and magnetic susceptibilities exhibit different values in Gaussian and SI units
even when these constants are dimensionless. In this note we fix this practical inconvenience by
redefining the permittivity and permeability of a lin…
The role of emissivity during the cooling of a body: an experimental design for a laboratory classroom
Mechanisms of heat transfer and Newton’s law of cooling are introduced in the first physics and
biophysics courses for a number of university science majors. Several papers have commented on the
derivation of the exponential decay and validity of t…
Which dipole are you studying in lab?
We explore the similarities and differences between the electric dipole studied in introductory
physics and the purportedly equivalent elementary experiment in which the electric potential is
measured on a conductive sheet as a current flows. The for…
A note on the electric and magnetic susceptibilities
The linear electric and magnetic susceptibilities exhibit different values in Gaussian and SI units
even when these constants are dimensionless. In this note we fix this practical inconvenience by
redefining the permittivity and permeability of a lin…
A general realistic treatment of the disk paradox
Mechanical angular momentum is not conserved in systems involving electromagnetic fields with
non-zero electromagnetic field angular momentum. Conservation is restored only if the total
(mechanical and field) angular momentum is considered. Previous …
Transmission and reflection of a molecule with a dipole moment incident upon a circular hole in a two-dimensional conducting sheet
We consider a one-dimensional molecule with a permanent electric dipole moment incident along the
line of symmetry of a circular hole in an infinite two-dimensional conducting sheet. We calculate
the probabilities of reflection p R and transmission p…
Which dipole are you studying in lab?
We explore the similarities and differences between the electric dipole studied in introductory
physics and the purportedly equivalent elementary experiment in which the electric potential is
measured on a conductive sheet as a current flows. The for…
The role of emissivity during the cooling of a body: an experimental design for a laboratory classroom
Mechanisms of heat transfer and Newton’s law of cooling are introduced in the first physics and
biophysics courses for a number of university science majors. Several papers have commented on the
derivation of the exponential decay and validity of t…
An elementary approach to the gravitational Doppler shift
In college physics courses, treatment of the Doppler effect is usually done far from the first
introduction to kinematics. This paper aims to apply a graphical treatment to describe the
gravitational redshift, by considering the Doppler effect in two…
NASA, FEMA Hold Asteroid Emergency Planning Exercise
What would we do if we discovered a large asteroid on course to impact Earth? That highly unlikely scenario was discussed at a recent NASA-FEMA tabletop exercise.
Watching Summer Clouds on Titan
New video shows bright clouds of methane drifting across Saturn’s largest moon, Titan.
Watching Summer Clouds on Titan
New video shows bright clouds of methane drifting across Saturn’s largest moon, Titan.
NASA, FEMA Hold Asteroid Emergency Planning Exercise
What would we do if we discovered a large asteroid on course to impact Earth? That highly unlikely scenario was discussed at a recent NASA-FEMA tabletop exercise.
Week In Images
Our week through the lens: 31 October – 4 November 2016
ESA and the Vatican join forces to save data in the digital age
At a ceremony held in Vatican City today, ESA and the Vatican Apostolic Library have agreed to continue their years-long cooperation on the preservation, management and exploitation of archived information.
Ultimate Precision Bound of Quantum and Subwavelength Imaging
Author(s): Cosmo Lupo and Stefano PirandolaQuantum imaging can distinguish between two point-like light sources that are classically indistinguishable, according to theoretical analysis. This may lead to coherent imaging techniques as alternatives to c…
Far-Field Superresolution of Thermal Electromagnetic Sources at the Quantum Limit
Author(s): Ranjith Nair and Mankei TsangQuantum imaging can distinguish between two point-like light sources that are classically indistinguishable, according to theoretical analysis. This may lead to coherent imaging techniques as alternatives to clas…
Laser Particle Stimulated Emission Microscopy
Author(s): Sangyeon Cho, Matjaž Humar, Nicola Martino, and Seok Hyun Yun
Embedding nanoscale lasers in a biological cell could lead to optical images with resolution smaller than the laser light’s wavelength.
[Phys. Rev. Lett. 117, 193902] Published Fri Nov 04, 2016
Laser Particle Stimulated Emission Microscopy
Author(s): Sangyeon Cho, Matjaž Humar, Nicola Martino, and Seok Hyun Yun
Embedding nanoscale lasers in a biological cell could lead to optical images with resolution smaller than the laser light’s wavelength.
[Phys. Rev. Lett. 117, 193902] Published Fri Nov 04, 2016
Ultimate Precision Bound of Quantum and Subwavelength Imaging
Author(s): Cosmo Lupo and Stefano PirandolaQuantum imaging can distinguish between two point-like light sources that are classically indistinguishable, according to theoretical analysis. This may lead to coherent imaging techniques as alternatives to c…
Far-Field Superresolution of Thermal Electromagnetic Sources at the Quantum Limit
Author(s): Ranjith Nair and Mankei TsangQuantum imaging can distinguish between two point-like light sources that are classically indistinguishable, according to theoretical analysis. This may lead to coherent imaging techniques as alternatives to clas…
There’s super-hype for this month’s Super Moon
The Full Moon on November 13/14 will be bigger and brighter than normal, but it won’t be easy to tell from a casual glance.
New images of the Schiaparelli crash site
High-res color images give more insight about the lander’s demise
Scientists snare their first ever observations of a solar wave erupting upward from a sunspot
Solar scientists have a problem: They haven’t been able to fully explain why the Sun’s atmosphere is about 100 times hotter than its surface.
Now, observations of a solar wave rising up from a sunspot may help explain at least one of the wa…
Pío XI
Earth observation image of the week: Chile’s Bernardo O’Higgins National Park and the Pío XI Glacier, also featured on the Earth from Space video programme
Schiaparelli crash site in colour
New high-resolution images taken by a NASA orbiter show parts of the ExoMars Schiaparelli module and its landing site in colour on the Red Planet.
Sentinel satellites reveal east–west shift in Italian quake
New information on the effects of the 30 October earthquake that struck central Italy continues to emerge as scientists analyse radar scans from satellites.
Stretching an Elastic Loop: Crease, Helicoid, and Pop Out
Author(s): Yasuaki Morigaki, Hirofumi Wada, and Yoshimi Tanaka
Experiments with paper ribbons show how one can predict the final shape of a loop when the ribbon’s ends are pulled tight.
[Phys. Rev. Lett. 117, 198003] Published Thu Nov 03, 2016
Stretching an Elastic Loop: Crease, Helicoid, and Pop Out
Author(s): Yasuaki Morigaki, Hirofumi Wada, and Yoshimi Tanaka
Experiments with paper ribbons show how one can predict the final shape of a loop when the ribbon’s ends are pulled tight.
[Phys. Rev. Lett. 117, 198003] Published Thu Nov 03, 2016
Earth from Space
Join us Friday, 4 November, at 10:00 CET for the ‘Earth from Space’ video programme. This week features the glaciers of Chile’s Bernardo O’Higgins National Park
The largest space scope ever built is finished
The James Webb Space Telescope is finally completed after 20 years
A record of ancient tectonic stress on Mars
Sets of ridges and troughs some 1000 km north of the giant Olympus Mons volcano contain a record of the intense tectonic stresses and strains experienced in the Acheron Fossae region on Mars 3.7–3.9 billion years ago.
Hermitian and gauge-covariant Hamiltonians for a particle in a magnetic field on cylindrical and spherical surfaces
We construct the Hermitian Schrödinger Hamiltonian of spin-less particles and the gauge-covariant
Pauli Hamiltonian of spin one-half particles in a magnetic field, which are confined to cylindrical
and spherical surfaces. The approach does not requi…
An elementary argument for the magnetic field outside a solenoid
The evaluation of the magnetic field inside and outside a uniform current density infinite solenoid
of uniform cross-section is an elementary problem in classical electrodynamics that all
undergraduate Physics students study. Symmetry properties of t…
Curiosity Mars Rover Checks Odd-looking Iron Meteorite
Laser-zapping of a globular, golf-ball-size object on Mars by NASA’s Curiosity rover confirms that it is an iron-nickel meteorite fallen from the Red Planet’s sky.
Curiosity Mars Rover Checks Odd-looking Iron Meteorite
Laser-zapping of a globular, golf-ball-size object on Mars by NASA’s Curiosity rover confirms that it is an iron-nickel meteorite fallen from the Red Planet’s sky.
Mars in Lanzarote
Human spaceflight and robotic exploration image of the week: Exploring Mars on Earth
Measurement-Device-Independent Quantum Key Distribution Over a 404 km Optical Fiber
Author(s): Hua-Lei Yin, Teng-Yun Chen, Zong-Wen Yu, Hui Liu, Li-Xing You, Yi-Heng Zhou, Si-Jing Chen, Yingqiu Mao, Ming-Qi Huang, Wei-Jun Zhang, Hao Chen, Ming Jun Li, Daniel Nolan, Fei Zhou, Xiao Jiang, Zhen Wang, Qiang Zhang, Xiang-Bin Wang, and Jian…
Measurement-Device-Independent Quantum Key Distribution Over a 404 km Optical Fiber
Author(s): Hua-Lei Yin, Teng-Yun Chen, Zong-Wen Yu, Hui Liu, Li-Xing You, Yi-Heng Zhou, Si-Jing Chen, Yingqiu Mao, Ming-Qi Huang, Wei-Jun Zhang, Hao Chen, Ming Jun Li, Daniel Nolan, Fei Zhou, Xiao Jiang, Zhen Wang, Qiang Zhang, Xiang-Bin Wang, and Jian…
Italy on the move
Scientists are analysing Sentinel-1 radar images from before and after the 30 October earthquake that struck central Italy to reveal just how much the ground has shifted
Massive stars destroy their own spawning grounds
The Pillars of Creation are also sites of cosmic destruction
The Thirty Meter Telescope has a possible new location
After protests, the TMT board had to conceive a Plan B
Astronomers find a ‘nearly-naked’ supermassive black hole
A close galactic encounter gave these astronomers an interesting discovery
Why did the apple fall? A new model to explain Einstein?s gravity
Newton described gravity as an attractive force between two masses but Einstein?s General Theory of
Relativity provides a very different explanation. Implicit in Einstein?s theory is the idea that
gravitational effects are the result of a distortion …
Why did the apple fall? A new model to explain Einstein’s gravity
Newton described gravity as an attractive force between two masses but Einstein’s General Theory of
Relativity provides a very different explanation. Implicit in Einstein’s theory is the idea that
gravitational effects are the result of a distort…
Do it yourself: make your own thermoacoustic engine with steel wool or rice
The construction of two demonstrators of thermoacoustic engines is proposed in this paper, using
common material from hardware stores. A brief discussion about the thermoacoustic effect highlights
the main parameters controlling the generation of sel…
New, Space-Based View of Human-Made Carbon Dioxide
Scientists have produced the first global maps of human emissions of carbon dioxide ever made solely from satellite observations, using data from NASA’s OCO-2.
New, Space-Based View of Human-Made Carbon Dioxide
Scientists have produced the first global maps of human emissions of carbon dioxide ever made solely from satellite observations, using data from NASA’s OCO-2.
Making a stir
Technology image of the week: friction stir welding used to make a titanium propellant tank for space
We may have some insight into how Saturn got its gorgeous rings
A new model may explain what caused the rings around Saturn, Uranus, and Neptune
The solar system may have ejected Moon and Mars-sized worlds into interstellar space
By crunching numbers, astronomers discover that many worlds may be gone forever from our corner of the cosmos.
An orientable search coil
We provide a design for a low cost orientable search coil that can be used to investigate the
variation of magnetic flux with angle. This experiment is one of the required practical activities
in the current A level physics specification for the AQA …
Analysing simple motions using the Doppler effect—‘seeing’ sound
The Doppler effect has seen widespread use in the past hundred years. It is used for medical
imaging, for measuring speed, temperature, direction, etc, and it makes the spatial relations of
motion easy to map. The Doppler effect also allows GPS recei…
Teaching renewable energy using online PBL in investigating its effect on behaviour towards energy conservation among Malaysian students: ANOVA repeated measures approach
This research aimed to investigate whether online problem based learning (PBL) approach to teach
renewable energy topic improves students’ behaviour towards energy conservation. A renewable energy
online problem based learning (REePBaL) instruction…
‘Gamma Anna’: a classroom demonstration for teaching the concepts of gamma imaging
Gamma imaging is at the interface of medicine and physics and thus its teaching is important in both
fields. Pedagogic literature highlights the benefits of interactive demonstrations in teaching: an
increase in enjoyment and interest, as well as imp…
A modern Galileo tale
The year 2014 marked the four-hundred-and-fiftieth anniversary of Galileo’s birth, making it the
perfect occasion to present and illustrate a G eo G ebra applet which reproduces some of Galileo’s
celebrated experiments on the uniformly accelerate…
Analysing simple motions using the Doppler effect??seeing? sound
The Doppler effect has seen widespread use in the past hundred years. It is used for medical
imaging, for measuring speed, temperature, direction, etc, and it makes the spatial relations of
motion easy to map. The Doppler effect also allows GPS recei…
?Gamma Anna?: a classroom demonstration for teaching the concepts of gamma imaging
Gamma imaging is at the interface of medicine and physics and thus its teaching is important in both
fields. Pedagogic literature highlights the benefits of interactive demonstrations in teaching: an
increase in enjoyment and interest, as well as imp…
An orientable search coil
We provide a design for a low cost orientable search coil that can be used to investigate the
variation of magnetic flux with angle. This experiment is one of the required practical activities
in the current A level physics specification for the AQA …
Analysing simple motions using the Doppler effect—‘seeing’ sound
The Doppler effect has seen widespread use in the past hundred years. It is used for medical
imaging, for measuring speed, temperature, direction, etc, and it makes the spatial relations of
motion easy to map. The Doppler effect also allows GPS recei…
Teaching renewable energy using online PBL in investigating its effect on behaviour towards energy conservation among Malaysian students: ANOVA repeated measures approach
This research aimed to investigate whether online problem based learning (PBL) approach to teach
renewable energy topic improves students’ behaviour towards energy conservation. A renewable energy
online problem based learning (REePBaL) instruction…
‘Gamma Anna’: a classroom demonstration for teaching the concepts of gamma imaging
Gamma imaging is at the interface of medicine and physics and thus its teaching is important in both
fields. Pedagogic literature highlights the benefits of interactive demonstrations in teaching: an
increase in enjoyment and interest, as well as imp…
A modern Galileo tale
The year 2014 marked the four-hundred-and-fiftieth anniversary of Galileo’s birth, making it the
perfect occasion to present and illustrate a G eo G ebra applet which reproduces some of Galileo’s
celebrated experiments on the uniformly accelerate…
Metawaveguide for Asymmetric Interferometric Light-Light Switching
Author(s): Han Zhao, William S. Fegadolli, Jiakai Yu, Zhifeng Zhang, Li Ge, Axel Scherer, and Liang Feng
An all-optical switch design uses an asymmetric waveguide that reduces the beam power requirements, which is essential for making such devices practical.
[Phys. Rev. Lett. 117, 193901] Published Mon Oct 31, 2016
Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory
Author(s): A. Aab et al. (Pierre Auger Collaboration)The Pierre Auger Observatory has detected more muons from cosmic-ray showers than predicted by the most up-to-date particle-physics models.[Phys. Rev. Lett. 117, 192001] Published Mon Oct 31, 2016
Metawaveguide for Asymmetric Interferometric Light-Light Switching
Author(s): Han Zhao, William S. Fegadolli, Jiakai Yu, Zhifeng Zhang, Li Ge, Axel Scherer, and Liang Feng
An all-optical switch design uses an asymmetric waveguide that reduces the beam power requirements, which is essential for making such devices practical.
[Phys. Rev. Lett. 117, 193901] Published Mon Oct 31, 2016
Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory
Author(s): A. Aab et al. (Pierre Auger Collaboration)The Pierre Auger Observatory has detected more muons from cosmic-ray showers than predicted by the most up-to-date particle-physics models.[Phys. Rev. Lett. 117, 192001] Published Mon Oct 31, 2016