Elu, loodus, teadus ja tehnoloogia
Author(s): R. Kukreja, S. Bonetti, Z. Chen, D. Backes, Y. Acremann, J. A. Katine, A. D. Kent, H. A. Dürr, H. Ohldag, and J. Stöhr
X-ray magnetic circular dichroism detects the transient magnetic moments that are induced in a nonmagnetic material by spin injection from a ferromagnet.
[Phys. Rev. Lett. 115, 096601] Published Mon Aug 24, 2015
Author(s): Camilla Pellegrini, Johannes Flick, Ilya V. Tokatly, Heiko Appel, and Angel RubioTime-dependent density functional theory for quantum electrodynamics is successfully applied to electronic structure calculations via a quantum-optical treatmen…
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.
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 head of planetary science says the agency could send a spacecraft to explore Uranus and/or Neptune, as well as their ocean moons.
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.
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…
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…
A set of classical multi-wire proportional chambers was designed and constructed with the main
purpose of efficient cosmic muon detection. These detectors are relatively simple to construct, and
at the same time are low cost, making them ideal for ed…
We present a simple diffraction experiment with m -bonacci gratings as a new interesting
generalization of the Fibonacci ones. Diffraction by these non-conventional structures is proposed
as a motivational strategy to introduce students to basic rese…
Our week through the lens: 17-21 August 2015
Author(s): I. Gierz, F. Calegari, S. Aeschlimann, M. Chávez Cervantes, C. Cacho, R. T. Chapman, E. Springate, S. Link, U. Starke, C. R. Ast, and A. Cavalleri
Ultrafast dynamics of photoexcited electron-hole pairs produced by subfemtosecond pulses in graphene may have implications for petahertz electronic and optoelectronic devices.
[Phys. Rev. Lett. 115, 086803] Published Fri Aug 21, 2015
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.
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.
New images show a pockmarked icy landscape of Saturn’s moon.
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?
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.
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…
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…
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 …
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?
Simon Jolly talks to David Smith about his early physics career and his current involvement in
proton therapy in the UK.
A smartphone acceleration sensor is used to study two-dimensional harmonic oscillations. The data
recorded by the free android application, Accelerometer Toy, is used to determine the periods of
oscillation by graphical analysis. Different patterns o…
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…
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.
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…
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…
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…
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,…
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…
The continuing fascination of young people with celestial bodies leads them to pose challenging
questions to their science teachers, such as how was the universe born? How were the stars formed?
In this paper we present an extremely inexpensive but h…
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…
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…
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…
If the end of a long chain, which is contained in an elevated beaker, is dropped over the edge of
the beaker and falls, it is observed that as the speed of the chain increases the chain rises to
form a loop well above the top of the beaker. The name …
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…
Description unavailable
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 …
An Ariane 5 lifted off tonight from Europe’s Spaceport in Kourou, French Guiana, and delivered two telecom satellites into their planned orbits.
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.
In a series of media opportunities Wednesday, Aug. 26, through Friday, Aug. 28, NASA experts will present an up-to-date global outlook on current conditions and future projections of sea level rise.
Relive the highlights of NASA’s Spitzer Space Telescope mission with a new digital calendar.
Author(s): M. G. Aartsen et al. (IceCube Collaboration)
Using Earth as a neutrino filter, the IceCube neutrino experiment strengthens its claim that it has detected neutrinos from powerful astrophysical accelerators outside our Galaxy.
[Phys. Rev. Lett. 115, 081102] Published Thu Aug 20, 2015
Author(s): C. Zhang, A. M. Grubb, A. J. Seed, P. Sampson, A. Jákli, and O. D. Lavrentovich
Edge dislocations in chiral smectic liquid crystals are directly observed using cryo-transmission electron microscopy.
[Phys. Rev. Lett. 115, 087801] Published Thu Aug 20, 2015
Author(s): Silvia Viciani, Manuela Lima, Marco Bellini, and Filippo CarusoA system of optical fibers and cavities is used to simulate noise-assisted transport through a network. This system could potentially allow the contribution of noise to the trans…
This new image of powerful remnants of dead stars and their mighty action on the surrounding gas from ESA’s XMM-Newton X-ray observatory reveals some of the most intense processes taking place at the centre of our galaxy, the Milky Way.
The study shows that pebble accretion can produce the observed structure of the solar system as long as the pebbles formed slowly enough that the growing gas giant planets have time to gravitationally interact with one another.
Curiosity investigated a geological contact zone and rocks that are unexpectedly high in silica and hydrogen content.
A new NASA report shows land in California’s San Joaquin Valley is sinking faster than ever as Californians continue pumping groundwater in response to the historic drought.
NASA scientists provide real science to debunk wild Internet rumors about an alleged September asteroid impact.
Author(s): C. Adolph et al. (COMPASS Collaboration)A new axial-vector meson is observed during the diffractive reaction of pions on a hydrogen target.[Phys. Rev. Lett. 115, 082001] Published Wed Aug 19, 2015
Author(s): A. Depresseux, E. Oliva, J. Gautier, F. Tissandier, G. Lambert, B. Vodungbo, J-P. Goddet, A. Tafzi, J. Nejdl, M. Kozlova, G. Maynard, H. T. Kim, K. Ta Phuoc, A. Rousse, P. Zeitoun, and S. Sebban
Researchers have developed a compact, circularly polarized x-ray source for studying biological matrerials.
[Phys. Rev. Lett. 115, 083901] Published Wed Aug 19, 2015
Technology image of the week: what look like Venetian blinds have been crucial to keep Rosetta’s temperature regulated
New modeling shows that the supernova shock wave that helped form the Sun also could be responsible for the spin of our solar system.
ESA astronaut Andreas Mogensen, Soyuz spacecraft commander Sergei Volkov and Kazakh cosmonaut Aidyn Aimbetov arrived in Baikonur, Kazakhstan, yesterday. This is their last destination before heading to the International Space Station in th…
Today’s HTV supply launch from Japan to the International Space Station also marks the arrival in orbit of one of ESA’s smallest missions yet – a CubeSat which will test miniaturised technologies for space, set to be followed by many more in coming years.
Human spaceflight and operations image of the week: aurora over Concordia research station in Antarctica
In their study of physics beyond the first year of University?termed upper-division in the US, many
of students? primary learning opportunities come from working long, complex back-of-the-book style
problems, and from trying to develop an understandi…
The paper describes the usage of a conventional lamp equipped with a linear halogen bulb for physics
experiments. The irradiance gain and limitation of spectral resolution are treated in detail
theoretically and verified experimentally. The analysis …
In this work, we propose an inexpensive laboratory practice for an introductory physics course
laboratory for any grade of science and engineering study. This practice was very well received by
our students, where a smartphone (iOS, Android, or Windo…
In their study of physics beyond the first year of University—termed upper-division in the US, many
of students’ primary learning opportunities come from working long, complex back-of-the-book style
problems, and from trying to develop an underst…
The stability of the new horizontal axis Levitron 3 is compared with that of the vertical axis
device. The rotation frequency ranges are similar because they are determined by the same
precessional micro-trap, for which some theory is given. But the …
After taking a low-angle selfie at its latest drilling site, NASA’s Curiosity Mars rover has departed the area called “Marias Pass,” where it had been working since May.
Mars enthusiasts can participate in NASA’s journey to Mars by adding their names to a silicon microchip headed to Mars aboard NASA’s InSight Mars lander, scheduled to launch next year.
Author(s): Raphael Bousso and Netta Engelhardt
A relation between the area of a novel class of surfaces and the thermodynamic entropy has been proven, extending the results of Hawking’s 1971 area theorem.
[Phys. Rev. Lett. 115, 081301] Published Tue Aug 18, 2015
Author(s): Pree-Cha Kiatkirakajorn and Lucas GoehringExperiments explain why solidifying colloids sometimes form zigzagging stripes as they dry.[Phys. Rev. Lett. 115, 088302] Published Tue Aug 18, 2015
Author(s): Xiao Wang, Yisheng Chai, Long Zhou, Huibo Cao, Clarina-dela Cruz, Junye Yang, Jianhong Dai, Yunyu Yin, Zhen Yuan, Sijia Zhang, Runze Yu, Masaki Azuma, Yuichi Shimakawa, Huimin Zhang, Shuai Dong, Young Sun, Changqing Jin, and Youwen Long
Electric and magnetic polarization are spontaneously produced in an unlikely material—one with a highly symmetric crystal structure.
[Phys. Rev. Lett. 115, 087601] Published Tue Aug 18, 2015
The mission confirms that the Moon’s exosphere is made up of mostly helium, argon, and neon.
New dwarf galaxy candidates could mean our sky is more crowded than we thought.
Space Science Image of the Week: Mirrors like these will help JWST look back 13.5 billion years to see the first stars and galaxies forming.
Author(s): Alex Geringer-Sameth, Matthew G. Walker, Savvas M. Koushiappas, Sergey E. Koposov, Vasily Belokurov, Gabriel Torrealba, and N. Wyn EvansAre gamma rays from a nearby dwarf galaxy a beacon of dark matter or a false alarm?[Phys. Rev. Lett. 115,…
The newly discovered ring galaxy, dubbed Kathryn’s Wheel, is seven times closer than anything similar found before.
This study not only includes the well-known signatures of cities and streets, but also the effects of faint indirectly scattered light.
Author(s): Michal P. Heller and Michał Spaliński
The method of resurgence used in quantum field theories can address foundational aspects of relativistic hydrodynamics and its applicability to systems having large flow gradients.
[Phys. Rev. Lett. 115, 072501] Published Fri Aug 14, 2015
Author(s): Kungang Zhang, Fangjie Liu, Adam J. Williams, Xiaopeng Qu, James J. Feng, and Chuan-Hua ChenLiquid droplets that gather on a fine, water-repelling fiber kick themselves off the fiber as they coalesce.[Phys. Rev. Lett. 115, 074502] Published …
Our week through the lens: 10-14 August 2015
In a complicated mystery of double star systems, merging galaxies, and twin black holes, astronomers are explaining a series of unusual supernovae found beyond the typical confines of their galaxies.
NASA’s Cassini spacecraft will zip past Saturn’s moon Dione on Monday, Aug. 17 — the final close flyby of this icy satellite during the spacecraft’s long mission.
The Copernicus Emergency Management Service is using radar images from Sentinel-1A to map the devastating flood in Myanmar
ESA’s Rosetta today witnessed Comet 67P/Churyumov–Gerasimenko making its closest approach to the Sun. The exact moment of perihelion occurred at 02:03 GMT this morning when the comet came within 186 million km of the Sun.
Author(s): S. CarlipThe entropy of a black hole in loop quantum gravity is computed. The four-dimensional boundary term, that must be added to the loop quantum gravity action due to the presence of a black hole, maps to gravity in three dimensional spa…
Author(s): F. Albrecht, J. Repp, M. Fleischmann, M. Scheer, M. Ondráček, and P. Jelínek
A new scanning-probe-microscopy technique can image the polarity of individual chemical bonds.
[Phys. Rev. Lett. 115, 076101] Published Thu Aug 13, 2015
Author(s): Philipp Burda, Ruth Gregory, and Ian G. Moss
In some models, primordial black holes would have acted as seeds of Higgs vacuum decay reducing the Universe’s lifetime from trillions of years to fractions of a second. These regions of parameter space are thus ruled out.
[Phys. Rev. Lett. 115, 071303] Published Thu Aug 13, 2015
The new planet, discovered using the Gemini Planet Imager, is a million times fainter than its parent star and shows the strongest methane signature ever detected on an alien world.
After uncovering a major calibration error, scientists show that the newly corrected sunspot numbers now provide a homogenous record of solar activity dating back some 400 years.
The measurement of Maxwell’s displacement current has remained a veritable challenge. Here we
present a novel approach that allows a detailed verification in a lecture hall-type experiment.
Analytical solutions of the N -dimensional non-relativistic wave equation with the non-central
generalized Kratzer potential with arbitrary angular momentum have been investigated within the
framework of the asymptotic iteration method. In hyperspher…
The R?nyi entanglement entropy is calculated exactly for mode-partitioned isolated systems such as
the two-mode squeezed state and the multi-mode Silbey?Harris polaron ansatz state. Effective
thermodynamic descriptions of the correlated partitions ar…
Team-based learning (TBL) is an established model of group work which aims to improve students?
ability to apply discipline-related content. TBL consists of a readiness assurance process (RAP),
student groups and application activities. While TBL has…
The time-dependent quantum perturbation theory developed by Born, Heisenberg and Jordan in 1926 is
revisited. We show that it not only reproduces the standard theory formulated in the interaction
picture, but also allows one to construct more accurat…
Geckos have inspired a technology to make things stick together in space.
Author(s): R. Aaij et al. (LHCb Collaboration)A new type of particle containing five quarks has been observed by the LHCb experiment.[Phys. Rev. Lett. 115, 072001] Published Wed Aug 12, 2015
Author(s): A. Lazicki, J. R. Rygg, F. Coppari, R. Smith, D. Fratanduono, R. G. Kraus, G. W. Collins, R. Briggs, D. G. Braun, D. C. Swift, and J. H. Eggert
Solid tin has been compressed to a record high pressure without undergoing melting.
[Phys. Rev. Lett. 115, 075502] Published Wed Aug 12, 2015
When a Dutch company working on soil pollution teamed up with ESA to build a better, bacteria-based air filter for space, they also created the foundation for a new way of keeping iron pipelines from corroding in the ground.
Today, ESA signed contracts for the development of the Ariane 6 new‑generation launcher, its launch base and the Vega C evolution of the current small launcher.
By studying the lightest supermassive black hole found to date, scientists hope to better understand of such objects of different sizes grow.
The dramatic event on Comet 67P/Churyumov-Gerasimenko was so powerful that it even pushed away the incoming solar wind.
Next time you tune in to public radio or the hottest Top 40 radio station, you’ll be using some of the same tools NASA uses to unravel the mysteries of the universe.
A dramatic outburst from Rosetta’s target comet is recorded by several instruments, including the Double Focusing Mass Spectrometer, which uses NASA-built electronics.
Author(s): Bing Liu, Thijs H. Besseling, Alfons van Blaaderen, and Arnout ImhofRod-shaped particles in a liquid arrange into a variety of structures when subjected to confining walls, an effect that might be used to design optical materials.[Phys. Rev….