Elu, loodus, teadus ja tehnoloogia
Author(s): H. Yasuda and J. Yang
Structures made solely from folded rigid planes exhibit both tunable negative Poisson’s ratio and structural bistability allowing for the construction of new types of mechanical metamaterials.
[Phys. Rev. Lett. 114, 185502] Published Tue May 05, 2015
Author(s): Stephen M. Wu, John E. Pearson, and Anand BhattacharyaA spin current is experimentally generated in various insulating paramagnets using thermal gradients, a surprising result as, unlike ferromagnetic insulators, paramagnets do not hold thei…
Human spaceflight and operations image of the week: Sentinel-2 mission control team trains for launch
A team discovered an exceptionally luminous galaxy more than 13 billion years in the past; it existed so long ago that it appears to be only 100 million years old.
The ability to peek into the atmospheres of rocky “super-Earths” and observe conditions on their surfaces marks an important milestone toward identifying habitable planets outside the solar system.
NASA’s Mars Exploration Program has begun using systematic precautions to prevent Mars orbiters from flying too close to each other.
Author(s): Rafael G. Henríquez Rivera, Kushal Sinha, and Michael D. Graham
During blood flow, white blood cells and platelets segregate near vessel walls, a phenomenon known as margination. A new kinetic theory allows the different segregation regimes to be defined, showing that, under certain conditions, the concentration of cells at the walls goes to zero.
[Phys. Rev. Lett. 114, 188101] Published Mon May 04, 2015
Author(s): A. J. Bestwick, E. J. Fox, Xufeng Kou, Lei Pan, Kang L. Wang, and D. Goldhaber-Gordon
Thin films of magnetic topological insulators can exhibit a nearly ideal quantum Hall effect without requiring an applied magnetic field.
[Phys. Rev. Lett. 114, 187201] Published Mon May 04, 2015
Clear evidence now suggests that the heating mechanism depends on regular but intermittent explosive bursts of heat, rather than on continuous gradual heating.
Further observations by astronomers using the Green Bank Telescope revealed that this pulsar is part of only a handful of double neutron star systems.
Space Science Image of the Week: This cool view of the Cygnus region in the Milky Way reveals young stars waiting to be born
Registration is open for a free online course that provides an introduction to monitoring climate change using satellite Earth observation.
NASA and its partners are gathering the best available science and information on the April 25 magnitude 7.8 earthquake in Nepal to assist in relief and humanitarian operations.
Author(s): Niklas Romming, André Kubetzka, Christian Hanneken, Kirsten von Bergmann, and Roland Wiesendanger
Atomic-scale imaging reveals the shape and size of a technologically interesting magnetic quasiparticle.
[Phys. Rev. Lett. 114, 177203] Published Fri May 01, 2015
Scientists have discovered an exoplanet with Saturn’s mass and Jupiter’s radius orbiting a small, cool star.
This finding may help astronomers understand how the largest black holes were able to grow so rapidly in the early universe.
Our week through the lens: 27 April – 1 May 2015
With four years and 4,105 orbits around the planet, the spacecraft determined Mercury’s surface composition, revealed its geological history, discovered its internal magnetic field is offset from the planet’s center, and verified its polar deposi…
An elongated crater called “Spirit of St. Louis,” with a rock spire in it, dominates a recent scene from the panoramic camera (Pancam) on NASA’s Mars Exploration Rover Opportunity.
Author(s): P.-T. Brun, Basile Audoly, Neil M. Ribe, T. S. Eaves, and John R. Lister
A new model can predict the patterns formed by a viscous jet falling onto a moving surface.
[Phys. Rev. Lett. 114, 174501] Published Thu Apr 30, 2015
Author(s): Victor V. Albert, Leonid I. Glazman, and Liang JiangSystems with nontrivial topological properties can be constructed from electric circuits consisting of capacitors and inductors.[Phys. Rev. Lett. 114, 173902] Published Thu Apr 30, 2015
Author(s): M. Aguilar et al. (AMS Collaboration)Higher accuracy measurements of the proton cosmic ray spectrum at high energies show that it deviates from the long held single power law behavior.[Phys. Rev. Lett. 114, 171103] Published Thu Apr 30, 2015
Author(s): G. D’Adamo, D. Marenduzzo, C. Micheletti, and E. Orlandini
An applied electric field could reconfigure the structure of colloidal defects dispersed within a liquid crystal.
[Phys. Rev. Lett. 114, 177801] Published Thu Apr 30, 2015
The new Industry Portal provides concrete information on ESA’s Business Opportunities, informative material on how to do business with ESA and access to useful educational tools
The Sentinel-1A satellite has given us a clearer picture of the ground deformation caused by the 25 April earthquake in Nepal
Niisiis, neli aastat ümber Merkuuri tiirelnud USA kosmoseagentuuri sond Messenger lõpetas oma töö ja kukkus alla. Missioon oli erakordselt edukas, kestis kolm aastat kauem kui planeeritud ning andis teadlastele ohtralt uurimismaterjali. Üks kõige kaunimaid pilte, mis Merkuuri kohta saadi, on näha allpool. Sellele klikkides avaneb täisvaade, mis on eriti detailirohke. Aga mis on õigupoolest pildil? […]
New observations demonstrate how the different dusty pillars of this iconic object are distributed in space and reveal many new details, including a previously unseen jet from a young star.
The space telescope has observed a baffling X-ray glow at the heart of the Milky Way that could involve different classes of stellar corpses.
After a mission of nearly 11 years, the spacecraft has run out of fuel and will smash into the planet’s surface at about 3:26 p.m. EDT.
In this paper, the Schr?dinger equation in the presence of a screened Coulomb potential and a
uniform field is analysed using matched asymptotic expansions. When the cup well potential has a
very short range, approximate analytical expressions for th…
In this we design a simple and insightful way to achieve Kepler?s first two laws for planets. The
approach is quite different from what we have done for the Earth before. It is because the
planet?Sun distance can be determined only through the Earth?…
In this paper, the Schrödinger equation in the presence of a screened Coulomb potential and a
uniform field is analysed using matched asymptotic expansions. When the cup well potential has a
very short range, approximate analytical expressions for t…
The rarely mentioned fact that a pure boost in general distorts the axes of the boosted frame is
shown to influence significantly the Thomas precession effect as observed in the laboratory frame.
As a result the Thomas precession appears to be accomp…
We discuss the role of the internal forces and how their work changes the energy of a system. We
illustrate the contribution of the internal work to the variation of the system’s energy, using a
pure mechanical example, a thermodynamical system and…
In this we design a simple and insightful way to achieve Kepler’s first two laws for planets. The
approach is quite different from what we have done for the Earth before. It is because the
planet–Sun distance can be determined only through the Ea…
In this work we revisit the study of the gravitational interaction in the context of the special
theory of relativity. It is found that, as long as the equivalence principle is respected, a
relativistic nonlinear energy conservation theorem arises in…
NASA’s NuSTAR has spotted a mysterious glow of high-energy X-rays in the heart of the Milky way that could be the “howls” of dead stars as they feed on stellar companions.
On 25 April, a 7.8-magnitude earthquake struck Nepal, claiming over 5000 lives and affecting millions of people. Satellite images are being used to support emergency aid organisations, while geo-scientists are using satellite measurements …
Technology image of the week: Unboxing BepiColombo’s Mercury Magnetospheric Orbiter at ESA’s Test Centre
ESA is set to support Japan’s ‘touch-and-go’ Hayabusa-2 spacecraft, now en route to a little-known asteroid, helping to boost the scientific return from this audacious mission.
Author(s): Armin Tavakoli, Alley Hameedi, Breno Marques, and Mohamed BourennaneA significant gain in the success probability of recovering bits from an encoded sequence has been achieved with quantum random access codes, outperforming their classical c…
Scientists interpreted the latest image data to reveal that the dwarf planet has broad surface markings – some bright, some dark – including a bright area at one pole that may be a polar cap.
Despite young molecular clouds containing far less oxygen than the Sun, theorists still found as much water vapor in the early universe as we see in the Milky Way today.
The team discovered the planets by detecting a wobble of the star HD 7924 as a result of the gravitational pull of the planets orbiting around it.
New antiviral drugs to treat Ebola patients in West Africa have been tested with the help of a transportable diagnostics laboratory developed with ESA’s support.
NASA’s Low-Density Supersonic Decelerator test vehicle has arrived at the U.S. Navy’s Pacific Missile Range Facility in Kauai, Hawaii.
Author(s): A. Palladino, G. Pagliaroli, F. L. Villante, and F. Vissani
The highest energy neutrinos ever recorded have a flavor distribution of neutrinos that is consistent with the particles having a cosmic origin.
[Phys. Rev. Lett. 114, 171101] Published Tue Apr 28, 2015
Author(s): M. G. Aartsen et al. (IceCube Collaboration)
The highest energy neutrinos ever recorded have a flavor distribution of neutrinos that is consistent with the particles having a cosmic origin.
[Phys. Rev. Lett. 114, 171102] Published Tue Apr 28, 2015
Human spaceflight and operations image of the week: Newly refitted Airbus A310 aircraft on the runway and ready for its first flight for weightless research
Observations revealed new properties of the first exoplant ever discovered around a normal star — 51 Pegasi b.
Studies show that supernovae with strong engines and lighter particles produce gamma-ray bursts.
Space Science Image of the Week: Saturn’s moon Hyperion may be a potato-shaped lump of porous rock but, as discovered by Cassini, it is more intriguing than it seems
The Deep Space Atomic Clock mission will explore how to better navigate spacecraft and collect data with more precision.
The websites and a mobile app selected for best-of-the-Web honors represent the diversity of NASA’s online offerings.
Author(s): Stephanie Höhn, Aurelia R. Honerkamp-Smith, Pierre A. Haas, Philipp Khuc Trong, and Raymond E. Goldstein
Images of an algal embryo transitioning into an adult give physicists a rare opportunity to test a mechanical model of morphogenesis.
[Phys. Rev. Lett. 114, 178101] Published Mon Apr 27, 2015
Author(s): Zengwei Zhu, Xiao Lin, Juan Liu, Benoît Fauqué, Qian Tao, Chongli Yang, Youguo Shi, and Kamran Behnia
Measurements of the Fermi surface of WTe2 demonstrate that it is nearly a perfectly compensated semimetal.
[Phys. Rev. Lett. 114, 176601] Published Mon Apr 27, 2015
The Event Horizon Telescope has made a step toward taking the first detailed pictures of black holes by adding the South Pole Telescope to its instrumentation lineup.
Aatomid ja molekulid astuvad keemilistesse reaktsioonidesse ergastatud seisunditest, millel on väga lühike eluiga ning mida ei ole seni olnud võimalik katseliselt uurida. Nüüd on Masakazu Yamazaki (Tohoku Ülikool, Jaapan) töörühm saanud selliste, vaid pikosekundeid kestvate seisundite kohta infot, mõõtes neilt hajunud elektronide energiaid. Tulevikus loodavad uurijad saada 3D kujutisi ergastatud olekutes molekulide elektronpilvedest ning uurida […]
An Ariane 5 has lifted off from Europe’s Spaceport in Kourou, French Guiana and delivered two telecom satellites into their planned orbits.
Teadlased on suutnud ära mõõta üksiku magnetväljas ringorbiidil liikuva elektroni kiirguse. Eksperimendis, mida tuntakse ka Projekt 8 nime all ja milles osales 27 teadlast kuuest teadusasutusest USA-st ja Saksamaalt, mõõdeti väga täpselt ära üksiku elektroni kiirguse sagedus, mis omakorda annab täpse hinnangu elektroni energiale. Kui elektroni energia mõõtmise täpsust õnnestuks veel parandada, saaks sellistest eksperimentidest […]
Wolfgang Pauli (25.04.1900 – 14.12.1958) on sündinud Viinis juudi perekonnas, õppinud Müncheni ülikoolis. 19-aastaselt koostas ta põhjaliku ülevaate eri- ja üldrelatiivsusteooriast, mida Einstein ise kõrgelt hindas ja mis jäi aastateks parimaks sellekohaseks ülevaateks. Doktorikraadi kaitses 1922 Müncheni ülikoolis, seejärel töötas Göttingenis, Kopenhaagenis ja Hamburgis. 1928 pages ähvardava natsismiohu eest Šveitsi, kus sai Zürichi Tehnikaülikooli professoriks. […]
NASA’s Dawn spacecraft entered into its first science orbit on Thursday, April 23, as scheduled.
Author(s): P. Schellart et al.Radio waves generated by cosmic rays provide an unprecedented view of the elusive electric fields in thunderstorms.[Phys. Rev. Lett. 114, 165001] Published Fri Apr 24, 2015
Author(s): Ken H. Nagai, Yutaka Sumino, Raul Montagne, Igor S. Aranson, and Hugues Chaté
Large vortex and lane structures, as well as other coherent patterns, form in active systems when underdamped stochastic dynamics are modeled.
[Phys. Rev. Lett. 114, 168001] Published Fri Apr 24, 2015
Our week through the lens: 20-24 April 2015
If clusters of galaxies merge, a huge shock wave can drive the birth of a new generation of stars.
Hubble data has yielded tens of thousands of scientific papers, and its powerful camera continues to beam back breathtaking images of the universe.
These compact elliptical galaxies likely have been flying out of their home clusters by interactions with larger galaxies.
Earth observation image of the week: a Sentinel-1 image over the US state of Florida, also featured on the Earth from Space video programme
USA teadlased on loonud laseri, mis on ühtaegu väga väike ja reguleeritava lainepikkusega. Loodud laser on vaid mõne nanomeetri paksune, see koosneb läbipaistvate plaatide vahele asetatud ja värvainega ümbritsetud kulla nanoosakeste ruudustikust. Uue laseri abil loodetakse efektiivsemalt jälgida vähiuuringutes kasutatavaid biomarkereid. USA teadlaste loodud seadme skeem on alumisel pildil. Kollased täpid on seal kulla nano-osakesed, […]
This week marks the 25th anniversary of the launch of NASA’s Hubble Space Telescope, and JPL is celebrating its significant role in the historic mission.
The second satellite for Europe’s Copernicus programme is set for launch on 12 June. Discover the ‘colour vision’ mission
The latest satellite for the European Commission’s environmental Copernicus programme has arrived safe and sound in French Guiana for launch on 12 June. Carrying a multispectral imager, Sentinel-2A is set to give us a new perspective of our land and vegetation.
Author(s): Rajita Menon and Kirill S. KorolevMicrobial cooperation involves the diffusion of nutrients from one species to another, but too high a diffusion rate weakens the cooperative bond.[Phys. Rev. Lett. 114, 168102] Published Thu Apr 23, 2015
Author(s): Matthew Evans et al. Ground-based interferometric gravitational wave detectors are predicted to suffer from instabilities that strongly limit the sensitivity of the detectors. Arising from a coupling between optical and mechanical resonances…
Celebrating 25 years of the Hubble Space Telescope, this montage presents the incredible range of images that have helped to shape our view of the Universe
This glittering tapestry of young stars exploding into life in a dramatic fireworks display has been released today to celebrate 25 incredible years of the Hubble Space Telescope.
Join us Friday, 24 April, at 10:00 CEST for the ‘Earth from Space’ video programme. This week features a Sentinel-1 image over the US state of Florida
The coalition hopes to better understand the various components of exoplanets, as well as how the stars and neighbor planets interact to support life.
The sparkling centerpiece of Hubble’s silver anniversary fireworks is a giant cluster of about 3,000 stars called Westerlund 2.
Katie Paterson’s ESA-supported work Campo del Cielo, Field of the Sky – which included a symbolic return to space for a chunk of meteorite – has been shortlisted for the International Prize for Contemporary Art, granted by the Foundation Prince Pierre de Monaco.
Paljude komposiitmaterjalidest valmistatud detailide valmistamisel ja parandamisel on vaja neid kuumutada. Kui töödeldavad esemed on väga suured või on nad juba kusagile külge kruvitud (näiteks lennukile), siis võib kuumutamine olla vägagi kulukas ja aeganõudev protsess. Ka energia tarbimise poolest – tüüpiliselt tuleb sellisel töötlusel esmalt üles soojendada ahi, alles pärast seda saab asuda detaili kallale, […]
The possibility of quantum interference of a composite object with many internal degrees of freedom
is studied, such that the internal degrees play a role of an internal environment. In particular, if
the internal degrees have a capacity for an irrev…
In my article (Featonby 2015 Phys. Educ. 50 256), I looked at how the behaviour of a spinning top
differs when it is set to spin on a gentle incline.
Creativity can be viewed from different perspectives, such as the creative thinking process, the
product, the creative environment and the individual. The physics domain, which is based on
experiments, research, hypotheses and thinking outside the bo…
Improving the scientific literacy of non-scientists is an important aim, both because of the
ever-increasing impact of science on our lives and because understanding science enriches our
experience of the natural world. One route to improving scienti…
A projectile is launched vertically from the surface of an isolated planet. It collides with and
sticks to a satellite of equal mass that is initially moving in a circular orbit around the planet.
Conservation of mechanical energy, angular momentum, …
The possibility of quantum interference of a composite object with many internal degrees of freedom
is studied, such that the internal degrees play a role of an internal environment. In particular, if
the internal degrees have a capacity for an irrev…
A new coupled pendulum chain system is developed to vividly simulate the solitary solutions of the
sine-Gordon (SG) equation. Transmission processes of three kinds of solitons (kink, anti-kink and
breather) are systematically observed by using a high…
We describe an experiment in which the rotation of the polarization of light propagating in an
optically active water solution of D-fructose tends to be inhibited by frequent monitoring whether
the polarization remains unchanged. This is an example o…
The link between trigonometry and forces can be a conceptually difficult one for some A-level
students. This article describes a simple, practical investigation that students can carry out using
three force metres to find the horizontal and vertical …
This article describes an alternative method to determine the refractive index of transparent
liquids. The method only requires a laser pointer, a ruler and a modified fish tank.
The phenomena of free-fall weightlessness have been demonstrated to students for many years in a
number of different ways. The essential basis of all these demonstrations is the fact that in
free-falling, gravitationally accelerated systems, the weig…
Improving the scientific literacy of non-scientists is an important aim, both because of the
ever-increasing impact of science on our lives and because understanding science enriches our
experience of the natural world. One route to improving scienti…
A student realizes that a point particle that is able to rise at a given point P 0 at height H when
launched vertically from the origin O of a Cartesian plane at a fixed initial speed V 0 cannot
reach, by means of a direct shot from a small spring cannon, a point P positioned at the same height
H and distance d from P 0 , with 0 < d ≤ R , where R is the maximum horizontal distance attainable
with an optimum throw at an angle of 45°. However, the student realizes that, in the absence of air
resistance, conservation of energy does not prevent this possibility. Therefore, in order to reach
point P , the student uses a perfectly reflecting surface, opportunely inclined with respect to the
horizontal. The full story of how this is done will be narrated in this article.
David Smith talks to Nobel Prize-winning graphene pioneer Konstantin Novoselov about his early
career in Russia and his move to Manchester, where he is currently involved in setting up the
National Graphene Institute.
Creativity can be viewed from different perspectives, such as the creative thinking process, the
product, the creative environment and the individual. The physics domain, which is based on
experiments, research, hypotheses and thinking outside the bo…
The bounce of a ball is a seemingly innocuous event that can be used to illustrate many aspects of
elementary and even advanced mechanics. Both normal and oblique bounces on a rigid surface are
considered in this article, emphasizing qualitative feat…
Many icebergs are vulnerable to capsizing. In doing so the gravitational potential energy of the ice
is increased, while that of the displaced sea water is decreased. Applying the principle of the
conservation of energy shows that by capsizing, there…
