Understanding Physics is a great end in itself, but is also crucial to keep pace with developments
in modern technology. Wireless power transfer, known to many only as a means to charge electric
toothbrushes, will soon be commonplace in charging phon…
Revisiting the ‘unmixing experiment’ through argumentation
This paper focuses on a series of activities for students at middle school to college level,
designed to instill a sound understanding of fluids and the properties of fluids. The first
activities investigate diffusion and molecular size and these are…
How to make a soft, rough surface transparent
A transparent elastomer is made opaque by making one of its surfaces rough. By squeezing the rough
surface against a piece of glass, the roughness is smoothed out and the elastomer becomes
transparent.
Measurement of the sound absorption coefficient for an advanced undergraduate physics laboratory
We present a simple experiment that allows advanced undergraduates to learn the basics of the
acoustic properties of materials. The impedance tube-standing wave method is applied to study the
normal absorption coefficient of acoustics insulators. The…
Analyzing collisions in classical mechanics using mass–momentum diagrams
We show the value of mass–momentum diagrams for analyzing collision problems in classical mechanics
in one dimension. Collisions are characterized by the coefficient of restitution and the momenta of
the interacting particles both before and after …
Equilibrium charge distribution on a finite straight one-dimensional wire
The electrostatic properties of uniformly charged regular bodies are prominently discussed on
college-level electromagnetism courses. However, one of the most basic problems of electrostatics
that deals with how a continuous charge distribution reach…
Geometric mechanics of ray optics as particle dynamics: refraction index with cylindrical symmetry
Starting from the Fermat principle of geometrical optics, we analyse the ray dynamics in a graded
refractive index system device with cylindrical symmetry and a refractive index that decreases
parabolically with the radial coordinate. By applying Ham…
Electro-optic control of photographic imaging quality through ‘Smart Glass’ windows in optics demonstrations
An experimental setup allowing the modeling of conditions in optical devices and in the eye at
various degrees of scattering such as cataract pathology in human eyes is presented. The scattering
in cells of polymer-dispersed liquid crystals (PDLCs) a…
Geometric mechanics of ray optics as particle dynamics: refraction index with cylindrical symmetry
Starting from the Fermat principle of geometrical optics, we analyse the ray dynamics in a graded
refractive index system device with cylindrical symmetry and a refractive index that decreases
parabolically with the radial coordinate. By applying Ham…
Equilibrium charge distribution on a finite straight one-dimensional wire
The electrostatic properties of uniformly charged regular bodies are prominently discussed on
college-level electromagnetism courses. However, one of the most basic problems of electrostatics
that deals with how a continuous charge distribution reach…
Analyzing collisions in classical mechanics using mass–momentum diagrams
We show the value of mass–momentum diagrams for analyzing collision problems in classical mechanics
in one dimension. Collisions are characterized by the coefficient of restitution and the momenta of
the interacting particles both before and after …
Measurement of the sound absorption coefficient for an advanced undergraduate physics laboratory
We present a simple experiment that allows advanced undergraduates to learn the basics of the
acoustic properties of materials. The impedance tube-standing wave method is applied to study the
normal absorption coefficient of acoustics insulators. The…
Electro-optic control of photographic imaging quality through ‘Smart Glass’ windows in optics demonstrations
An experimental setup allowing the modeling of conditions in optical devices and in the eye at
various degrees of scattering such as cataract pathology in human eyes is presented. The scattering
in cells of polymer-dispersed liquid crystals (PDLCs) a…
Can Poor Air Quality Mask Global Warming’s Effects?
In the 1900s, the U.S. warmed everywhere except the Southeast, where warming didn’t begin till the 1990s. A study finds air quality improvements may have played a role.
Can Poor Air Quality Mask Global Warming’s Effects?
In the 1900s, the U.S. warmed everywhere except the Southeast, where warming didn’t begin till the 1990s. A study finds air quality improvements may have played a role.
Primordial Black Holes and $r$-Process Nucleosynthesis
Author(s): George M. Fuller, Alexander Kusenko, and Volodymyr Takhistov
A dramatic scenario in which a compact black hole eats a spinning neutron star from inside might explain a nearby galaxy’s unexpectedly high abundance of heavy elements.

[Phys. Rev. Lett. 119, 061101] Published Mon Aug 07, 2017
Conductance of a Freestanding Conjugated Molecular Wire
Author(s): Torben Jasper-Tönnies, Aran Garcia-Lekue, Thomas Frederiksen, Sandra Ulrich, Rainer Herges, and Richard Berndt
The conductance of a molecule standing perpendicular to a substrate is found to be dependent on the geometry, orbital symmetries, and bonds of the molecule.

[Phys. Rev. Lett. 119, 066801] Published Mon Aug 07, 2017
Astronomers just mapped the inside of a supernova
It turns out these events could be even more impressive than we thought.
Box of life
Technology image of the week: This pioneering microbiology life-support experiment flew in space 30 years ago this week
Summer fireworks
Space Science Image of the Week: Rosetta captured views of the comet during its most active phase two years ago
New Clues to Universe’s Structure Revealed
Three JPL scientists are part of the Dark Energy Survey, which is helping to further our understanding of the structure of the universe.
New Clues to Universe’s Structure Revealed
Three JPL scientists are part of the Dark Energy Survey, which is helping to further our understanding of the structure of the universe.
Nonlinear Self-Action of Light through Biological Suspensions
Author(s): Anna Bezryadina, Tobias Hansson, Rekha Gautam, Benjamin Wetzel, Graham Siggins, Andrew Kalmbach, Josh Lamstein, Daniel Gallardo, Edward J. Carpenter, Andrew Ichimura, Roberto Morandotti, and Zhigang ChenA laser beam sent through a suspension…
Oscillation of Branching Ratios Between the $\mathrm{D}(2s)+\mathrm{D}(1s)$ and the $\mathrm{D}(2p)+\mathrm{D}(1s)$ Channels in Direct Photodissociation of ${\mathrm{D}}_{2}$
Author(s): Jie Wang, Qingnan Meng, and Yuxiang MoPreviously predicted oscillations in the electronic states of atoms after the dissociation of a hydrogen molecule are observed experimentally.[Phys. Rev. Lett. 119, 053002] Published Fri Aug 04, 2017
Search for the Dimuon Decay of the Higgs Boson in $pp$ Collisions at $\sqrt{s}=13\text{ }\text{ }\mathrm{TeV}$ with the ATLAS Detector
Author(s): M. Aaboud et al. (ATLAS Collaboration)The ATLAS collaboration has placed an upper limit on the decay rate of Higgs bosons into pairs of muons within a factor of three of the Standard Model prediction.[Phys. Rev. Lett. 119, 051802] Published …
Week in Images
Our week through the lens: 31 July – 4 August 2017
New Horizons may visit twice the object for the same price
MU69 could be hiding a strange secret: it’s one object, not two.
Total Eclipse of 2016 HO3?
Learn whether Earth’s second moon can cause solar eclipses.
Pressure-Dependent Friction on Granular Slopes Close to Avalanche
Author(s): Jérôme Crassous, Antoine Humeau, Samuel Boury, and Jérôme Casas
Experiments show that the mass of an object determines whether it slides down a sandy slope, which may explain why ants get trapped in antlions’ traps.

[Phys. Rev. Lett. 119, 058003] Published Thu Aug 03, 2017
Paolo and Mares
Human spaceflight image of the week: ESA astronaut Paolo Nespoli tests his muscles
Two Voyagers Taught Us How to Listen to Space
Over the mission’s 40 years, NASA’s Voyager spacecraft have paved the way for modern deep space communications.
NASA Selects Proposals to Study Sun, Space Environment
NASA has selected nine proposals under its Explorers Program, including one managed by JPL.
Five Years Ago and 154 Million Miles Away: Touchdown!
NASA’s Curiosity Mars rover, which landed near Mount Sharp five years ago this week, is examining clues on that mountain about long-ago lakes on Mars.
Hubble Detects Exoplanet with Glowing Water Atmosphere
Scientists have discovered the strongest evidence to date for a stratosphere on a planet outside our solar system.
NASA Selects Proposals to Study Sun, Space Environment
NASA has selected nine proposals under its Explorers Program, including one managed by JPL.
Five Years Ago and 154 Million Miles Away: Touchdown!
NASA’s Curiosity Mars rover, which landed near Mount Sharp five years ago this week, is examining clues on that mountain about long-ago lakes on Mars.
Hubble Detects Exoplanet with Glowing Water Atmosphere
Scientists have discovered the strongest evidence to date for a stratosphere on a planet outside our solar system.
Two Voyagers Taught Us How to Listen to Space
Over the mission’s 40 years, NASA’s Voyager spacecraft have paved the way for modern deep space communications.
Optical Control of the Resonant Dipole-Dipole Interaction between Rydberg Atoms
Author(s): Sylvain de Léséleuc, Daniel Barredo, Vincent Lienhard, Antoine Browaeys, and Thierry Lahaye
The interaction between two Rydberg atoms is modified experimentally by addressing one of the two atoms with a laser beam.

[Phys. Rev. Lett. 119, 053202] Published Wed Aug 02, 2017
Frictional Magneto-Coulomb Drag in Graphene Double-Layer Heterostructures
Author(s): Xiaomeng Liu, Lei Wang, Kin Chung Fong, Yuanda Gao, Patrick Maher, Kenji Watanabe, Takashi Taniguchi, James Hone, Cory Dean, and Philip KimThe first experimental study of frictional drag effect between two monolayer sheets of graphene separa…
Astronomy magazine’s interactive eclipse 2017 widget
This tool has the answers to your eclipse day questions.
Breakthrough Starshot takes its first step toward interstellar travel
First … low Earth orbit. But eventually, these chip-sized spacecraft could explore Proxima Centauri.
Nanobot’s giant leap
Technology image of the week: This highly mobile jumping Nanobot is designed to make a profit on the Moon
Nanobot’s giant leap
Technology image of the week: This highly mobile jumping Nanobot is designed to make a profit on the Moon
Vega lofts two satellites on second launch this year

This morning Arianespace launched a Vega rocket carrying two Earth observation satellites for Italy, France and Israel encased in Vega’s lighter protective fairing.
Vega lofts two satellites on second launch this year

This morning Arianespace launched a Vega rocket carrying two Earth observation satellites for Italy, France and Israel encased in Vega’s lighter protective fairing.
The illusive sound of a Bundengan string
The acoustics of a vibrating string is frequently used as a simple example of how physics can be
applied in the field of art. In this paper we describe a simple experiment and analysis using a
clipped string. This experiment can generate scientific c…
Just how much do the planets affect the tides?
The influence of the planets, and planetary alignment on the Earth’s tides is addressed. Starting
from Newton’s law of gravitation, the tidal influence of any celestial body is expressed in terms of
its apparent size and its density. From this, p…
The illusive sound of a Bundengan string
The acoustics of a vibrating string is frequently used as a simple example of how physics can be
applied in the field of art. In this paper we describe a simple experiment and analysis using a
clipped string. This experiment can generate scientific c…
Just how much do the planets affect the tides?
The influence of the planets, and planetary alignment on the Earth’s tides is addressed. Starting
from Newton’s law of gravitation, the tidal influence of any celestial body is expressed in terms of
its apparent size and its density. From this, p…
Designing Kitaev Spin Liquids in Metal-Organic Frameworks
Author(s): Masahiko G. Yamada, Hiroyuki Fujita, and Masaki OshikawaVersatile materials called metal-organic frameworks might be good systems in which to search for quantum spin liquids.[Phys. Rev. Lett. 119, 057202] Published Tue Aug 01, 2017
How to watch the total solar eclipse online
Viewing options for astronomy fans outside totality.
Improving physics teaching materials on sound for visually impaired students in high school
When visually impaired students attend regular high school, additional materials are necessary to
help them understand physics concepts. The time for teachers to develop teaching materials for such
students is scarce. Visually impaired students in re…
Active learning of geometrical optics in high school: the ALOP approach
A group comparison experiment of two high school classes with pre and post instruction testing has
been carried out to study the suitability and advantages of using the active learning of optics and
photonics (ALOP) curricula in high schools of devel…
Improving physics teaching materials on sound for visually impaired students in high school
When visually impaired students attend regular high school, additional materials are necessary to
help them understand physics concepts. The time for teachers to develop teaching materials for such
students is scarce. Visually impaired students in re…
NASA’s Voyager Spacecraft Still Reaching for the Stars After 40 Years
Humanity’s farthest and longest-lived spacecraft, Voyager 1 and 2, achieve 40 years of operation and exploration this August and September.
First and Farthest: How the Voyagers Blazed Trails
Few missions can match the achievements of NASA’s groundbreaking Voyager 1 and 2 spacecraft during their 40 years of exploration.
NASA’s Voyager Spacecraft Still Reaching for the Stars After 40 Years
Humanity’s farthest and longest-lived spacecraft, Voyager 1 and 2, achieve 40 years of operation and exploration this August and September.
First and Farthest: How the Voyagers Blazed Trails
Few missions can match the achievements of NASA’s groundbreaking Voyager 1 and 2 spacecraft during their 40 years of exploration.
Mass and Moment of Inertia Govern the Transition in the Dynamics and Wakes of Freely Rising and Falling Cylinders
Author(s): Varghese Mathai, Xiaojue Zhu, Chao Sun, and Detlef LohseThe oscillations of neutrally buoyant cylinders depend on rotational freedom of the objects, as well as their mass.[Phys. Rev. Lett. 119, 054501] Published Mon Jul 31, 2017
Evidence for Weakly Correlated Oxygen Holes in the Highest-T_{c} Cuprate Superconductor HgBa_{2}Ca_{2}Cu_{3}O_{8+δ}
Author(s): A. Chainani, M. Sicot, Y. Fagot-Revurat, G. Vasseur, J. Granet, B. Kierren, L. Moreau, M. Oura, A. Yamamoto, Y. Tokura, and D. Malterre
Oxygen-hole correlations in HgBa2Ca2Cu3O8+δ, the highest Tc mercury-based cuprate superconductor, are found to be weaker than those seen in any other cuprate superconductor.

[Phys. Rev. Lett. 119, 057001] Published Mon Jul 31, 2017
Testing Galileo
Each Galileo satellite must go through a rigorous test campaign to assure its readiness for space
NASA has selected nine proposals for Explorers Program
These missions will study the Sun and our space environment, as well as develop instruments.
Extreme stellar factory

Space Science Image of the Week: Massive stars emerge from glowing gas and dust in one of the Milky Way’s most active stellar nurseries
Extreme stellar factory

Space Science Image of the Week: Massive stars emerge from glowing gas and dust in one of the Milky Way’s most active stellar nurseries
The flying kettle
A warm meal was quickly delivered by a drone from an ESA business incubator start-up to the last inhabitant in a remote village in Portugal.
The flying kettle
A warm meal was quickly delivered by a drone from an ESA business incubator start-up to the last inhabitant in a remote village in Portugal.
Docking replay
Paolo Nespoli and crewmates arrive at the International Space Station, aboard Soyuz MS-05
Docking replay
Paolo Nespoli and crewmates arrive at the International Space Station, aboard Soyuz MS-05
Welcome aboard
Paolo Nespoli, Randy Bresnik and Sergey Ryazanskiy arrive at the International Space Station
Welcome aboard
Paolo Nespoli, Randy Bresnik and Sergey Ryazanskiy arrive at the International Space Station
ESA astronaut Paolo Nespoli starts third mission on Space Station
ESA astronaut Paolo Nespoli, NASA astronaut Randy Bresnik and Roscosmos commander Sergei Ryazansky were launched into space yesterday from the Baikonur cosmodrome in Kazakhstan at 15:41 GMT (17:41 CEST). Their Soyuz MS-05 spacecraft circle…
ESA astronaut Paolo Nespoli starts third mission on Space Station
ESA astronaut Paolo Nespoli, NASA astronaut Randy Bresnik and Roscosmos commander Sergei Ryazansky were launched into space yesterday from the Baikonur cosmodrome in Kazakhstan at 15:41 GMT (17:41 CEST). Their Soyuz MS-05 spacecraft circle…
Asteroid Flyby Will Benefit NASA Detection and Tracking Network
Scientists plan to use a small asteroid’s close approach to Earth this October to test NASA’s network of observatories and scientists who work with planetary defense.
Asteroid Flyby Will Benefit NASA Detection and Tracking Network
Scientists plan to use a small asteroid’s close approach to Earth this October to test NASA’s network of observatories and scientists who work with planetary defense.
Size-Dependent Localization in Polydisperse Colloidal Glasses
Author(s): D. Heckendorf, K. J. Mutch, S. U. Egelhaaf, and M. Laurati
Imaging of the individual particles of a glass reveals the different behaviors of slightly smaller vs slightly larger particles, suggesting new ways to adjust the properties of commercial glasses.

[Phys. Rev. Lett. 119, 048003] Published Fri Jul 28, 2017
Week In Images
Our week through the lens: 24-28 July 2017
You can watch the Great American Eclipse in 4K on Astronomy.com
Our website will host an HD livestream of the event from Denver, Colorado.
Irrawaddy Delta
Earth observation image of the week: the peninsulas and islands of the Irrawaddy Delta in Myanmar captured by Sentinel-2, also featured on the Earth from Space video programme
Eclipse Balloons to Study Effect of Mars-Like Environment on Life
Microbes carried to the edge of space during the Aug. 21 eclipse will be analyzed by NASA’s Ames Research Center and JPL.
Eclipse Balloons to Study Effect of Mars-Like Environment on Life
Microbes carried to the edge of space during the Aug. 21 eclipse will be analyzed by NASA’s Ames Research Center and JPL.
Vita mission liftoff
Watch a replay of the Vita mission liftoff on 28 July
Vita mission liftoff
Watch a replay of the Vita mission liftoff on 28 July
Excitation and Control of Plasma Wakefields by Multiple Laser Pulses
Author(s): J. Cowley, C. Thornton, C. Arran, R. J. Shalloo, L. Corner, G. Cheung, C. D. Gregory, S. P. D. Mangles, N. H. Matlis, D. R. Symes, R. Walczak, and S. M. Hooker
Trains of laser pulses can be used to accelerate high-repetition-rate electron bunches to high energies.

[Phys. Rev. Lett. 119, 044802] Published Thu Jul 27, 2017
Superadditivity of the Classical Capacity with Limited Entanglement Assistance
Author(s): Elton Yechao Zhu, Quntao Zhuang, and Peter W. ShorThe capacity of quantum communication channels is predicted to switch from additive to superadditive when entanglement assistance is limited.[Phys. Rev. Lett. 119, 040503] Published Thu Jul 2…
Earth from Space

Join us Friday, 28 July, at 10:00 CEST for the ‘Earth from Space’ video programme
One plant at a time

Precision farming is set to become even more precise with a new camera drawing on satellite imaging.
Thanks to research with ESA on new cameras, hyperspectral cameras flying on drones are now able to see details as small as 4–5 cm.
One plant at a time

Precision farming is set to become even more precise with a new camera drawing on satellite imaging.
Thanks to research with ESA on new cameras, hyperspectral cameras flying on drones are now able to see details as small as 4–5 cm.
New Insights into Titan’s Complex Chemistry
Cassini has made a surprising detection of a molecule that is instrumental in producing complex organics within the hazy atmosphere of Saturn’s moon Titan.
New Insights into Titan’s Complex Chemistry
Cassini has made a surprising detection of a molecule that is instrumental in producing complex organics within the hazy atmosphere of Saturn’s moon Titan.
In-Plane Propagation of Light in Transition Metal Dichalcogenide Monolayers: Optical Selection Rules
Author(s): G. Wang, C. Robert, M. M. Glazov, F. Cadiz, E. Courtade, T. Amand, D. Lagarde, T. Taniguchi, K. Watanabe, B. Urbaszek, and X. Marie
The electric field of light emitted from transition metal dichalcogenide monolayers is found to be oriented perpendicularly to the monolayer plane.

[Phys. Rev. Lett. 119, 047401] Published Wed Jul 26, 2017
Ready to roll
Human spaceflight image of the week: Soyuz is rolled out ahead of Vita mission launch
Astronomers detect a supernova brighter than all the Milky Way’s stars combined
This may be the earliest supernova ever detected.
Africa grows green

Technology image of the week: ESA’s Proba-V minisatellite shows vegetation bloom across the African Sahel with the coming of the rainy season
Correlation of understanding of physics and psychological symptoms among high-school students in Greece
Depression may essentially influence cognitive function contributing to poor school performance. The
present study undertakes to determine the existence and strength of correlation between depressive
symptomatology and other mental conditions with th…
Finding the acceleration and speed of a light-emitting object on an inclined plane with a smartphone light sensor
This study investigates how the acceleration and speed of a light-emitting object on an inclined
plane may be determined using a smartphone’s light sensor. A light-emitting object was released from
the top of an inclined plane and its illuminance v…
Large, Distant Comets More Common Than Previously Thought
NASA’s WISE spacecraft, scanning the entire sky at infrared wavelengths, has delivered new insights about distant cometary wanderers.
NASA Solves a Drizzle Riddle
What makes clouds drizzle? A new study overturns a common assumption about raindrop size.
NASA Solves a Drizzle Riddle
What makes clouds drizzle? A new study overturns a common assumption about raindrop size.
Large, Distant Comets More Common Than Previously Thought
NASA’s WISE spacecraft, scanning the entire sky at infrared wavelengths, has delivered new insights about distant cometary wanderers.