Herschel and Planck teams are recipients of a prestigious aerospace industry award.
‘Hedgehog’ Robots Hop, Tumble in Microgravity
Hedgehog is a new concept for a robot that is specifically designed to overcome the challenges of traversing small solar system bodies.
NASA’s TES Satellite Instrument Gives New Insight into Water Cycle
NASA satellite measurements have given scientists a better understanding of what happens to rain and snow that fall on land, with a few surprising findings.
iriss blog
Follow the entire 10-day mission of ESA astronaut Andreas Mogensen to the International Space Station with behind-the-scenes info on the iriss blog
Galileo: fit for flight
Europe’s ninth and tenth Galileo satellites being fixed to the dispenser that will secure them during their 11 September launch
Spaceship Earth
Come and see how images of Earth from space show how science meets art at a new exhibition at Ars Electronica in Linz, Austria
At Saturn, one of these rings is not like the others
During equinox, one part of the rings didn’t cool as expected, which allowed scientists to model what they might be like on the inside.
What happened to early Mars’ atmosphere? New study eliminates one theory
A new analysis of the largest known deposit of carbonate minerals on Mars suggests that the original martian atmosphere may have already lost most of its carbon dioxide by the era of valley network formation.
Earth from Space
Join us Friday, 4 September, at 10:00 CEST for the ‘Earth from Space’ video programme. This week features a Sentinel-2A satellite image of the Australian Northern Territory.
Comment on ‘Wind-influenced projectile motion’
We comment on the article ‘Wind-influenced projectile motion’ by Bernardo et al (2015 Eur. J. Phys.
36 [http://dx.doi.org/10.1088/0143-0807/025016] 025016 ) where they examine the trajectory of a
particle that is subjected to gravity and a linear…
The statics of the wedge-shaped jar opener
This paper analyzes the static equilibrium of a simple jar opener on the basis of rigid-body
mechanics with friction. The opener-lid system is described as a disk lying inside a wedge, where
only one side has friction; the disk is assumed to be acted…
NASA Soil Moisture Radar Ends Operations, Mission Science Continues
NASA SMAP observatory managers have determined its radar can no longer return data, but the mission continues to produce high-quality science with its radiometer instrument.
At Saturn, One of These Rings is not like the Others
One section of Saturn’s rings may be loaded with chunks of solid ice, possibly shards from a destroyed moon, according to a new study by Cassini scientists.
Cosmic recycling in the Prawn Nebula
This new image of IC 4628 (Gum 56) shows newborn stars formed by the remains of the most massive suns of a previous generation.
Comet Hitchhiker would take tour of small bodies
This concept puts forth a new way to get into orbit and land on comets and asteroids using the kinetic energy of these small bodies.
One man and his robot
Technology image of the week: ESA’s head of telerobotics introducing the rover Andreas Mogensen will soon be operating from orbit
Full replay: iriss launch
Watch the full replay of Soyuz TMA-18M launch to the International Space Station with ESA astronaut Andreas Mogensen
ESA astronaut Andreas Mogensen launched to Space Station
ESA astronaut Andreas Mogensen, commander Sergei Volkov and Aidyn Aimbetov were launched into space this morning2 Septemberat 04:38 GMT (06:38 CEST) from Baikonur cosmodrome, Kazakhstan.
iriss liftoff
Replay: ESA astronaut Andreas Mogensen, commander Sergei Volkov and Aidyn Aimbetov launched into space 2 September at 04:37 GMT (06:37 CEST) from Baikonur cosmodrome, Kazakhstan.
What Happened to Early Mars’ Atmosphere? New Study Eliminates One Theory
The amount of Martian atmosphere trapped by mineral formation appears inadequate to account for a warm environment when rivers cut valleys on ancient Mars.
Comet Hitchhiker Would Take Tour of Small Bodies
A concept for orbiting and landing on multiple asteroids and comets is being developed at JPL.
Space nears
Human spaceflight and operations image of the week: Thumbs up for the crew being launched to the International Space Station on Wednesday
LISA Pathfinder set for launch site
Scheduled for launch later this year, the mission will pave the way for future space-based projects to observe gravitational waves.
LISA Pathfinder set for launch site

LISA Pathfinder, ESA’s demonstrator for spaceborne observations of gravitational waves, is ready to leave for Europe’s Spaceport in Kourou, French Guiana.
Latest Galileos closing in on launch

Europe’s ninth and tenth Galileo satellites have been attached to the dispenser that will hold them during their flight up into space, then release them into their planned orbits.
New, Ultrathin Optical Devices Shape Light in Exotic Ways
Researchers have developed innovative flat, optical lenses as part of a collaboration between JPL and the Caltech.
NASA to Study Arctic Climate Change Ecosystem Impacts
NASA has begun a multi-year field campaign to investigate ecological impacts of the rapidly changing climate in Alaska and northwestern Canada.
Space Station docking
After a two-day flight in space, ESA astronaut Andreas Mogensen, commander Sergei Volkov and Aidyn Aimbetov will arrive at the International Space Station on 4 September. Watch live from 07:20 GMT (09:20 CEST)
Launch preview
Space Science Image of the Week: LISA Pathfinder, planned for a Vega launch later this year, will pave the way for gravitational-wave observatories in space
Utah’s Canyonlands becomes newest dark sky park
America’s darkest stretch of land gets another International Dark-Sky Park after National Park Service officials complete a sustained effort to make their lights night-sky friendly.
New Horizons Selects Kuiper Belt Target
NASA selects the next target for New Horizons, a Kuiper Belt object a billion miles past Pluto.
Greenland Campaign Takes Flight to Measure Ice Sheet
An airborne campaign over Greenland this summer helps scientists prepare for a satellite mission that will monitor global ice sheets.
NASA’s Summer Research on Sea Level Rise in Greenland
Researchers camped on Greenland’s ice sheet this summer studied streams that form atop the ice and carry meltwater to the ocean, where it adds to sea level rise.
Week In Images
Our week through the lens: 24-28 August 2015
Galileo satellites fuelled and ready for launcher attachment

Europe’s latest Galileo satellites are fully fuelled, leaving them ready to be attached to their launcher upper stage in preparation for their 11 September launch.
Interstellar seeds could create oases of life
New research by Harvard astrophysicists shows that if life can travel between the stars, it would spread in a characteristic pattern that we could potentially identify.
Hubble finds that the nearest quasar is powered by a double black hole
The finding suggests that the brilliant cores of active galaxies may commonly host two central supermassive black holes that fall into orbit about one another as a result of the merger between two galaxies.
Call For Media: Press briefing on launch of Galileo satellites 9/10
The next two satellites in Europe’s Galileo satellite navigation system will be launched together on 11 September, taking its orbital constellation a step closer to initial services. Media are invited to take part in an audio briefing on 1…
60 days and 60 nights … in bed
On 9 September, the first of 12 men will go to bed for 60 days as part of important research into stopping the wasting effects that spaceflight has on the human body. Although they may be putting their feet up, it is set to be a far from r…
Hawaii’s Supreme Court begins to hear Thirty Meter Telescope case
The state’s highest court started hearing oral arguments today over the fate of what could one day be the world’s largest telescope, which protesters say would desecrate their sacred land.
Understanding quantum phenomena without solving the Schrödinger equation: the case of the finite square well
An approximate formula for the energy levels of the bound states of a particle in a finite square
well are obtained, without using the Schrödinger equation. The physics and mathematics involved in
this approach are accessible to a gifted high school…
Now you can run naked and shout Eureka!
A common mistake in introductory physics textbooks is the omission of the buoyant force exerted by
the air on an object floating in a liquid. One previous work (Lan 2000 Phys. Teach. 38 [http://
http://dx.doi.org/10.1119/1.880449] 125 ) includes that…
Increase of entropy in the thermalization of two blocks: a simpler proof
The thermalization of two blocks with distinct initial temperatures put inside an insulated
recipient is an irreversible process to which the entropic version of the second law of
thermodynamics applies, so the entropy of this system must increase. I…
Derivation of the Drude conductivity from quantum kinetic equations
The Drude formula of ac (frequency-dependent) electric conductivity has been established as a simple
and practically useful model to understand the electromagnetic response of simple free-electron-like
metals. In most textbooks of solid-state physics…
Conservation laws and laser cooling of atoms
The straightforward application of energy and linear momentum conservation to the
absorption/emission of photons by atoms allows us to establish the essential features of laser
cooling of two level atoms at low laser intensities. The lowest attainabl…
Smallest 3-D Camera Offers Brain Surgery Innovation
A tiny 3-D camera for potential use in brain surgery, has been honored with a technology award.
Longer flight to the International Space Station for Andreas Mogensen
ESA astronaut Andreas Mogensen will leave for the International Space Station from Baikonur cosmodrome in Kazakhstan on 2 September with commander Sergei Volkov and Kazakh cosmonaut Aidyn Aimbetov. Their flight in the Soyuz TMA-18M spacecr…
Station street view

‘Float’ and explore in detail each module of the International Space Station in this 360° panoramic view
Onsager Coefficients in Periodically Driven Systems
Author(s): Karel Proesmans and Christian Van den BroeckPeriodically driven thermodynamic systems near equilibrium cannot have finite fluxes with zero dissipation.[Phys. Rev. Lett. 115, 090601] Published Thu Aug 27, 2015
Astronaut Andreas to try sub-millimetre precision task on Earth from orbit
Early September will see the very first force-feedback-based teleoperation of a rover-based robotic arm system on Earth from the International Space Station, orbiting 400 km above our heads.
Discovering dust-obscured active galaxies as they grow
A research group discovered 48 dust-obscured galaxies, and since these galaxies are thought to harbor a rapidly growing black hole in their centers, these results give scientists clues for understanding the evolution of galaxies and supermassive black …
Chandra data suggest giant collision triggered “radio phoenix”
This reignited electron cloud radiating primarily at radio frequencies lies in Abell 1033.
The Fingerprints of Sea Level Rise
When you fill a sink, the water rises at the same rate to the same height in every corner. That’s not the way it works with our rising seas.
NASA Zeroes in on Ocean Rise: How Much? How Soon?
Intensive research, aided by NASA observations and analysis, points to an unavoidable future sea level rise of several feet. The question is, how quickly will it happen?
NASA’s OMG Mission Maps Greenland’s Coastline
NASA’s Oceans Melting Greenland program will study how the oceans are eating away at Greenland’s ice sheet and help scientists predict sea level rise.
Warming Seas and Melting Ice Sheets
NASA is applying its unique capabilities to the challenge of understanding global sea level rise.
A cosmic butterfly
The shimmering colours of the Twin Jet Nebula show off in new Hubble Space Telescope image
New Method for a Continuous Determination of the Spin Tune in Storage Rings and Implications for Precision Experiments
Author(s): D. Eversmann et al. (JEDI collaboration)The spin precession frequency of a charged particle in a storage ring is determined with substantially increased precision. This allows for improved measurements of the electric dipole moments of charg…
First Detection of the Acoustic Oscillation Phase Shift Expected from the Cosmic Neutrino Background
Author(s): Brent Follin, Lloyd Knox, Marius Millea, and Zhen PanThe free-streaming cosmic neutrino background has been observed by a unique decomposition of the acoustic oscillations in the cosmic microwave background.[Phys. Rev. Lett. 115, 091301] Pub…
Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at sqrt[s] =200 GeV
Author(s): L. Adamczyk et al. (STAR Collaboration)Measurements from STAR collaboration experiments at RHIC reveal that gluons and quarks may contribute equally to the spin angular momentum of a proton.[Phys. Rev. Lett. 115, 092002] Published Wed Aug 26…
Diffraction-Unlimited Position Measurement of Ultracold Atoms in an Optical Lattice
Author(s): Yuto Ashida and Masahito Ueda
Ultracold atoms in an optical lattice could be imaged on length scales below the diffraction limit by tracking the collapse of the system’s many-body wavefunction.

[Phys. Rev. Lett. 115, 095301] Published Wed Aug 26, 2015
New Hubble image of the Twin Jet Nebula
The new image highlights the bipolar planetary nebula’s shells and its knots of expanding gas in striking detail.
NASA satellites help explain coronal heating
Scientists have directly observed an essential part of the process for how magnetic waves in the Sun heat the solar plasma.
Dawn Sends Sharper Scenes from Ceres
The closest-yet views of Ceres, delivered by NASA’s Dawn spacecraft, show the small world’s features in unprecedented detail, including Ceres’ tall, conical mountain; crater formation features and narrow, braided fractures.
Ready for launch
Human spaceflight and operations image of the week: ESA astronaut Andreas Mogensen testing his spacesuit before launch on 2 September
Gaia’s first year of scientific observations

Last Friday, 21 August, ESA’s billion-star surveyor, Gaia, completed its first year of science observations in its main survey mode.
UCLA physicist tests theories of dark energy by mimicking the vacuum of space
His findings helped reveal how strongly dark energy interacts with normal matter.
Dawn sends sharper scenes from Ceres
The spacecraft’s view is now three times as sharp as in its previous mapping orbit, revealing exciting new details of this intriguing dwarf planet.
ESO and ESA Directors General sign Cooperation Agreement

On 20 August 2015 the Director General of ESO, Tim de Zeeuw, and the Director General of ESA, Johann-Dietrich Woerner, signed a cooperation agreement between the two organisations at ESO’s offices in Santiago, Chile. The ESA Director General was accompanied by Álvaro Giménez, Director of Science and Robotic Exploration at ESA, and Fabio Favata, Head of the ESA Programme Coordination Office.
Filamentary cosmic cloud

Space Science Image of the Week: ESA’s Herschel space observatory has explored the turbulent depths of a large, dense, and dramatic cosmic cloud known as Mon R2
NASA’s next big spacecraft mission could visit an ice giant
NASA’s head of planetary science says the agency could send a spacecraft to explore Uranus and/or Neptune, as well as their ocean moons.
The tumultuous heart of our galaxy
A new XMM-Newton image shows the powerful remnants of dead stars and their mighty action on the surrounding gas near the Milky Way’s center.
A simple derivation of the Schrödinger uncertainty relation
We show how the Schrödinger uncertainty relation for a pair of observables can be deduced using the
Cauchy–Schwarz inequality plus successive applications of the commutation relation involving the two
observables. Our derivation differs from the o…
A simple derivation of the Schr?dinger uncertainty relation
We show how the Schr?dinger uncertainty relation for a pair of observables can be deduced using the
Cauchy?Schwarz inequality plus successive applications of the commutation relation involving the two
observables. Our derivation differs from the orig…
Week In Images
Our week through the lens: 17-21 August 2015
Chasing ice

Satellite images show that the fastest moving glacier in the world shed a chunk of ice measuring around 12.5 sq km this week – one of the most significant calving events on record.
New data from Antarctic detector firms up cosmic neutrino sighting
The evidence is important because it heralds a new form of astronomy using neutrinos, the nearly massless high-energy particles generated in black holes, massive exploding stars, and the energetic cores of galaxies.
Cassini’s final breathtaking close views of Dione
New images show a pockmarked icy landscape of Saturn’s moon.
Paper clip mystery?the question
The principle of this experiment is to lower a paperclip held on a cotton thread towards a string
magnet and deduce what might happen and why?
How does frosted glass become transparent??the answer
In my article (Temiz 2015 Phys. Educ . 50 509) I asked how we can see the other side of the frosted
paper. Here I answer the questions posed.
Exploring Kepler?s laws using an interactive whiteboard and Algodoo
Combining an interactive whiteboard with the right software, and with an appropriate instructional
approach, is crucial for its productive use in physics classrooms. We describe how the interactive
whiteboard can be used in combination with a physics…
Measuring Young?s modulus the easy way, and tracing the effects of measurement uncertainties
The speed of sound in a solid is determined by the density and elasticity of the material. Young?s
modulus can therefore be calculated once the density and the speed of sound in the solid are
measured. The density can be measured relatively easily, a…
A simple device for studying the relativity of motion
The fundamentals of classical mechanics are the foundation of more complicated and ingenious
physical theories. Therefore, an educational experiment revealing to students the physical nature of
mechanical phenomena is important. The effectiveness of …
Paper clip mystery—the question
The principle of this experiment is to lower a paperclip held on a cotton thread towards a string
magnet and deduce what might happen and why?
Interview: With proton precision
Simon Jolly talks to David Smith about his early physics career and his current involvement in
proton therapy in the UK.
Solving a problem by using what you know: a physicist looks at a problem in ecology
Two philosophical ideas motivate this paper. The first is an answer to the question of what is an
appropriate activity for a physicist. My answer is that an appropriate activity is anything where
the tools of a physicist enable him or her to make a c…
How does frosted glass become transparent?—the answer
In my article (Temiz 2015 Phys. Educ . 50 509) I asked how we can see the other side of the frosted
paper. Here I answer the questions posed.
Exploring Kepler’s laws using an interactive whiteboard and Algodoo
Combining an interactive whiteboard with the right software, and with an appropriate instructional
approach, is crucial for its productive use in physics classrooms. We describe how the interactive
whiteboard can be used in combination with a physics…
Low cost alternatives to commercial lab kits for physics experiments
Conducting experiments in physics using modern measuring techniques, and particularly those
utilizing computers, is often much more attractive to students than conducting experiments
conventionally. However, the cost of professional kits in the Czech…
A low-cost demonstration kit for locating an image formed by a plane mirror integrated with a ray diagram
This article introduces a low-cost, easy to make apparatus that can be used to locate the position
of an image formed by a plane mirror. The apparatus is combined with a method used to identify an
image’s position by drawing a ray diagram, based on…
Measuring Young’s modulus the easy way, and tracing the effects of measurement uncertainties
The speed of sound in a solid is determined by the density and elasticity of the material. Young’s
modulus can therefore be calculated once the density and the speed of sound in the solid are
measured. The density can be measured relatively easily,…
An unsolved electric circuit: a common misconception
Despite a number of theories in circuit analysis, little is known about the behaviour of ideal equal
voltage sources in parallel, connected across a resistive load. We neither have any theory that can
predict the voltage source that provides the load…
Work, gravitational energy and the Great Pyramid
According to the Greek historian Herodotus, it took a task force of 100 000 men and 20 years to
build up the Great Pyramid of Gizeh or Khufu’s Pyramid. In this work we discuss an analytical
solution obtained in the framework of basic Newtonian me…
A simple wave driver
This study was done to develop a simple and inexpensive wave driver that can be used in experiments
on string waves. The wave driver was made using a battery-operated toy car, and the apparatus can be
used to produce string waves at a fixed frequency…
Generating pedagogical content knowledge in teacher education students
Some pre-service teaching activities can contribute much to the learning of pedagogical content
knowledge (PCK) and subsequent teaching as these activities are generating PCK within the
pre-service teacher’s own classroom. Three examples are descri…
Optics demonstrations using cylindrical lenses
In this paper we consider the main properties of cylindrical lenses and propose several
demonstrational experiments that can be performed with them. Specifically we use simple glasses full
of water to demonstrate some basic geometrical optics princip…
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Time to ditch non-SI units in physics teaching?
The current use of two sets of units in the UK continues to be a source of muddle and confusion.
Young people are taught metric (SI) units in school but, in the outside world, still have to contend
with units such as inches, feet, pounds, stones and …
Ariane 5’s fourth launch of 2015

An Ariane 5 lifted off tonight from Europe’s Spaceport in Kourou, French Guiana, and delivered two telecom satellites into their planned orbits.
Cassini’s Final Breathtaking Close Views of Dione
A pockmarked, icy landscape looms beneath NASA’s Cassini spacecraft in new images of Saturn’s moon Dione taken during the mission’s last close approach to the small, icy world.