Controlling Photons for Use in Quantum Computing

first_img Rempe, a Director at Germany’s Max Planck Institute for Quantum Optics, and a team of fellow scientists believe they have solved the problem of producing and controlling photons by using an optical cavity. Rempe and his colleagues, Doctors Wilk, Webster and Specht at the Max Planck Institute, and Doctor Kuhn at the University of Oxford, have completed an experiment in which they were able to control the direction of a photon emitted from an atom, and its polarization. “This represents a great single-photon source that we can control,” Rempe says. The team details the results of the ground breaking experiment in a paper that appears in Physical Review Letters with the title, “Polarization-Controlled Single Photons.” In the experiment, laser pulses were used to make a single atom emit photons in a stream. “Typically, if you excite an atom and it emits a photon, you can’t control the direction it is emitted in,” Rempe explains. He describes, in an email, an optical cavity, consisting of a pair of mirrors facing each other. These mirrors are separated by a distance of only 1 mm, and used to set the direction of the emitted photons. “The cavity influences the atom so that photons it produces are likely to be emitted in a direction perpendicular to the surface of the mirrors,” Rempe says. “Once emitted, a photon bounces between the mirrors thousands of times before passing through one of them to escape into the laboratory in a known direction.”Rempe admits that the generation of single photons inside an optical cavity has been demonstrated before. But this new experiment adds another layer to the work done before. Rempe’s group takes the control demonstrated in prior optical cavity experiments one step further by being able to determine the polarization of the photons produced. A magnetic field is applied to the atom, allowing different polarizations to be produced, depending on the frequency of the laser pulses used. So, not only can the direction of the photons be controlled, but it is now also possible to completely control all the photon’s degrees of freedom.This, Rempe says, is only a first step towards using quantum processes for computing and communicating. He hopes that his team’s work can lead to additional advances in quantum information processing. “We should be able to extend our scheme to produce photons that are entangled with the internal state of the atom,” says Rempe. “This would be a first step towards creating a quantum network which would allow quantum information to be transferred between different laboratories.” He emphasizes that this new process “opens more possibilities in quantum information processing.” By Miranda Marquit, Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Citation: Controlling Photons for Use in Quantum Computing (2007, February 13) retrieved 18 August 2019 from https://phys.org/news/2007-02-photons-quantum.html “Quantum information science makes use of the quantum nature of particles to perform computation,” Gerhard Rempe explains to PhysOrg.com. “One approach is to use single particles of light – photons – as the basis of the computer, storing information in a property of the light such as its polarization. To do this, you need a source able to produce photons under full control.” This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.center_img Explore further An atom in a cavity extracts highly pure single photons from weak laser lightlast_img read more

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Can Newtons 2nd Law be Violated on Earth

first_img Ignatiev has devised a way of detecting one such special case, dealing with small accelerations on earth. This type of experiment is something widely considered so difficult that it has been dismissed in the past as impossible. “We already have observation of this theory in astrophysical evidence,” Ignatiev, a scientist at Melbourne’s Theoretical Physics Research Institute in Australia, points out. “I want to look at how it works on earth.” Ignatiev’s Suggestion on how this could be accomplished has been published in Physical Review Letters as “Is Violation of Newton’s Second Law Possible?”And the implications if Newton’s 2nd Law is violated under special conditions on earth? “Well,” says Ignatiev, “this is dealing with fundamental physics. If Newton’s Law can be seen to be violated on Earth, then everything we know has to be re-evaluated.”But this is where the difficulties with Ignatiev’s Suggestion begin. “The conditions for testing this are really special,” he explains. “Time and place have to be accounted for.” According to Ignatiev, the possible places to conduct this experiment lie 80 degrees north and south of the equator. “These are latitudes in places like Antarctica and Greenland — not exactly hospitable areas.” But timing is important as well. “It must be very finely tuned,” Ignatiev insists. “Only two instances during the year, around the two equinox dates, for about 1/1000th of a second.”If these experiments were to take place, Ignatiev says that scientists would look for what he calls the SHLEM effect. This acronym stands for static high latitude equinox modified inertia and would be noticed in a condition where the forces of the earth’s rotation on its axis, and of the orbital force of the earth as it moves around the sun, would be canceled out. “This would lead to a tiny shift to be detected,” Ignatiev explains.But how feasible is this? Aside from the calculations that he says he already has for figuring the dates, times and locations for the SHLEM effect to manifest, Ignatiev says that the experiment could be done — it’s not impossible as previously thought. “Gravitational wave detectors are great starting points,” he says. Ignatiev explains that searching for tiny shifts in gravity could help understand tiny displacements, or accelerations. “Even though we are looking at different forces,” Ignatiev says, “the methods of detecting for gravity can be borrowed for this research. After all, gravity is a weak force with all sorts of tiny shifts, and the acceleration shifts are likewise weak and tiny.” And, he adds, there are plenty of these gravitational wave detectors in use and more being built. “There are many of them available, and they could further this research.”Despite the special conditions needed to test for violations of Newton’s 2nd Law on Earth, Ignatiev feels that it would be worthwhile. “This would be difficult, but not impossible. The SHLEM effect is the key. And if we can find a violation, it would be huge for fundamental physics.”Ignatiev’s paper is available free online at arxiv.org/abs/gr-qc/0612159 .Update: Paper ref. Phys. Rev. D 77, 102001 (2008), gr-qc/0802.1599Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Astrophysicists have found evidence that a corrected version of Newton’s 2nd Law (which deals with the acceleration of mass) works well on the grand scale of the universe. These modifications to Newtonian physics are known as “modified Newtonian dynamics (MOND). “Newton offers a foundation for classical mechanics in the relationship of force, mass and accelerations,” Alex Ignatiev explains to PhysOrg.com. “These are always true, except in special cases.” Citation: Can Newton’s 2nd Law be Violated on Earth? (2007, March 20) retrieved 18 August 2019 from https://phys.org/news/2007-03-newton-2nd-law-violated-earth.htmlcenter_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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Research group devises a way to control surface plasmon polaritons

first_img(a) Schematic of a unidirectional SPPs coupler. The coupler consists of an array of rectangular apertures with spatially varying orientations on a metal film. (b) Ordinary and anomalous refraction and diffraction for the two circular polarization states. The anomalous diffraction orders are asymmetric about the surface normal. (c) Dispersion curve of SPPs and the momentum matching condition for ordinary and anomalous diffraction orders. (d) Only one of the anomalous diffraction orders in (b) can be matched to the SPP dispersion relation to launch unidirectional SPP due to the asymmetry in the anomalous diffraction orders. Interestingly, when the helicity of the incident beam is reversed, so is the direction of the SPP excitation. SPP, surface plasmon polariton. Credit: (c) Nature Publishing Group, Light: Science & Applications (2013) 2, e70; doi:10.1038/lsa.2013.26 (Phys.org) —A team made up of researchers from the U.K., China and Germany has developed, for the first time, a way to control surface plasmon polaritons (SPPs), perhaps paving the way to integrated plasmonic circuits. In their paper published in Light: Science & Applications, describing their achievement, the team details how they created a metal film with nanometer-sized holes in it set in a certain way to allow for controlling the quasiparticles that arise during the interaction between light and a metal surface. © 2013 Phys.org Citation: Research group devises a way to control surface plasmon polaritons (2013, April 8) retrieved 18 August 2019 from https://phys.org/news/2013-04-group-surface-plasmon-polaritons.html Imaging nanoporous metals with beams of electrons provides deep insights into unusual optical properties The idea is essentially, to couple light to the surface of a metamaterial, in a specific direction. Normally, when light strikes such a surface, SPPs in the form of quasiparticles arise due to the mixing of light with surface electrons—they’re part light and part electron wave and exist only very near the metal surface. When the SPPs are excited under normal conditions, they tend to propagate in every direction, which isn’t very useful. In this new effort, the team devised a means for controlling the direction in which they flow.To get the SPPs to move only in the desired direction, the team created what they describe as a “metasurface” by covering a material with a metal film that had rectangular nanometer-sized holes in it—all situated in a particular fashion to impact the quasiparticles in desired ways. In so doing, they found they could control the direction in which the SPPs flowed by switching the circular polarization direction of the light that was shined on it—right or left. The holes cause phase delays, the researchers explain, which breaks the symmetry of the excitation of the SPPs in two directions, thus their orientation is critical. Because of that they found that that they could cause the SPPs to run in one or the other direction on command, by simply adjusting the apertures.The team took their research further by adding polarization modulators to the film which resulted in the creation of a plasmonic circuit that they were able to control. They next plan to improve the coupling that occurs in the film and to perhaps find a means for allowing LCD control of the propagation of the SPPs—that, they say, would allow for the design of much more complex circuits. More information: Helicity dependent directional surface plasmon polariton excitation using a metasurface with interfacial phase discontinuity, Light: Science & Applications (2013) 2, e70; doi:10.1038/lsa.2013.26 . Published online 29 March 2013AbstractSurface plasmon polaritons (SPPs) have been widely exploited in various scientific communities, ranging from physics, chemistry to biology, due to the strong confinement of light to the metal surface. For many applications, it is important that the free space photon can be coupled to SPPs in a controllable manner. In this Letter, we apply the concept of interfacial phase discontinuity for circularly polarizations on a metasurface to the design of a novel type of polarization-dependent SPP unidirectional excitation at normal incidence. Selective unidirectional excitation of SPPs along opposite directions is experimentally demonstrated at optical frequencies by simply switching the helicity of the incident light. This approach, in conjunction with dynamic polarization modulation techniques, opens gateway towards integrated plasmonic circuits with electrically reconfigurable functionalities.via Nanotechweb Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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Study shows graphene able to withstand a speeding bullet

first_img More information: Dynamic mechanical behavior of multilayer graphene via supersonic projectile penetration, Science 28 November 2014: Vol. 346 no. 6213 pp. 1092-1096. DOI: 10.1126/science.1258544ABSTRACTMultilayer graphene is an exceptional anisotropic material due to its layered structure composed of two-dimensional carbon lattices. Although the intrinsic mechanical properties of graphene have been investigated at quasi-static conditions, its behavior under extreme dynamic conditions has not yet been studied. We report the high–strain-rate behavior of multilayer graphene over a range of thicknesses from 10 to 100 nanometers by using miniaturized ballistic tests. Tensile stretching of the membrane into a cone shape is followed by initiation of radial cracks that approximately follow crystallographic directions and extend outward well beyond the impact area. The specific penetration energy for multilayer graphene is ~10 times more than literature values for macroscopic steel sheets at 600 meters per second.Press release Journal information: Science PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen A microbullet traveling at supersonic speed is captured in this composite of three timed images as it makes its way toward a suspended sheet of multilayer graphene. Experiments carried out at Rice University show graphene is 10 times better than steel at absorbing the energy of a penetrating projectile. The bubble at left is a polymer film expanding away from the gold substrate that transfers energy from a laser to the microbullet. Credit: Thomas Research Group/Rice University Materials scientist Edwin “Ned” Thomas, left, dean of the George R. Brown School of Engineering at Rice University, and Jae-Hwang Lee, a former postdoctoral researcher in his lab and now an assistant professor at the University of Massachusetts, Amherst, found graphene is stronger than steel in tests with microbullets. The researchers hold a polymer encasing bullets, the focus of a previous experiment. Credit: Tommy LaVergne/Rice University Explore further Materials scientist Edwin “Ned” Thomas, left, dean of the George R. Brown School of Engineering at Rice University, and Jae-Hwang Lee, a former postdoctoral researcher in his lab and now an assistant professor at the University of Massachusetts, Amherst, found graphene is stronger than steel in tests with microbullets. The researchers hold a polymer encasing bullets, the focus of a previous experiment. Credit: Tommy LaVergne/Rice University Research unlocks potential of super-compound Rice University scientists fired microbullets at supersonic speeds in experiments that show graphene is 10 times better than steel at absorbing the energy of a penetrating projectile. Credit: Jae-Hwang Leecenter_img A microbullet traveling at supersonic speed is captured in this composite of three timed images as it makes its way toward a suspended sheet of multilayer graphene. Experiments carried out at Rice University show graphene is 10 times better than steel at absorbing the energy of a penetrating projectile. The bubble at left is a polymer film expanding away from the gold substrate that transfers energy from a laser to the microbullet. Credit: Thomas Research Group/Rice University Citation: Study shows graphene able to withstand a speeding bullet (2014, November 28) retrieved 18 August 2019 from https://phys.org/news/2014-11-graphene-bullet.html Scientists know that graphene sheets are tough, due to their dense one atom think structure. Until now, however, no one has tested the material for use as armor—to protect against being struck by a speeding bullet. In this new effort, the researchers did just that, albeit at a much smaller scale.Scientists have yet to figure out a way to mass produce sheets of graphene in large sizes, thus, for this experiment, the researchers confined their efforts to a very small scale. Their firing range consisted of using a laser to vaporize gold filaments to serve as the gunpowder. The explosion pushed micron-sized glass bullets at graphene targets—10 to 100 sheets placed together to form a mat—at speeds up to 6,700 mph (approximately a third of the speed of a real bullet fired from an M16 machine gun). Electron microscopy was used to measure how well the graphene sheets absorbed the impact.The researchers found that the sheets were able to dissipate the energy of the bullet by stretching backwards—sort of like when someone jumps on a trampoline. Tiny cracks also formed radially, using up more of the energy. In analyzing the results, the researchers found that the graphene was able to perform twice as well as Kevlar, the material currently used in bullet-proof vests, and up to ten times as well as steel. Put another way, the graphene was able to absorb aproximately 0.92MJ/kg of projectile energy, while steel can typically absorb 0.08MJ/kg when both are being tested at similar speeds. Play Jae-Hwang Lee briefly shows how the micro-ballistic experiment was performed using the advanced laser induced projectile impact test (a-LIPIT) apparatus. Credit: Rice University The ability of graphene to dissipate energy, the team explains, is due to a high degree of stiffness combined with low density, which means that energy can move through it very quickly, allowing for the dissipation of energy from something traveling as fast as a bullet. The researchers efforts show that graphene could very well mean a better bullet-proof vest, if a way could be found to produce it in enough quantity and at a low enough price. © 2014 Tech Xplore (Phys.org)—A team of researchers working at Rice University in the U.S. has demonstrated that graphene is better able to withstand the impact of a bullet than either steel or Kevlar. In their paper published in the journal Science, the team describes how they set up a miniature firing range in their laboratory and used it to test the strength of graphene sheets. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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How particles pack in a confined space

first_imgPictured is a sampling of clusters of the Platonic solids, each of which packs densely inside a sphere. These clusters are a subset of a larger collection generated by Teich et al. using Monte Carlo simulations with spherical confinement. Results show a wide variety of resultant symmetries and structures for clusters of up to 60 constituent polyhedra, with implications for a range of experimental applications, including colloidal materials design, drug delivery, and the creation of metamaterials. Image courtesy of E. Teich and J. Proctor (University of Michigan, Ann Arbor MI 48109). Credit: Erin G. Teich, Greg van Anders, Daphne Klotsa, Julia Dshemuchadse, and Sharon C. Glotzer Journal information: Proceedings of the National Academy of Sciences Citation: How particles pack in a confined space (2016, February 10) retrieved 18 August 2019 from https://phys.org/news/2016-02-particles-confined-space.html To discern how various anisotropic solids pack within a confined space, Erin G. Teich, Greg van Anders, Daphne Klotsa, Julia Dshemuchadse, and Sharon C. Glotzer of the University of Michigan, conducted Monte Carlo simulation studies to examine how Platonic solids pack three-dimensionally within a sphere. They compared these clusters to clusters of spherical particles packed within a sphere and found that unlike cluster packing in infinite space, within a closed container particle shape is less influential on the structure of optimal packings. Instead, the structures of optimal packings are significantly affected by the shape of the container, and clusters made of different particle shapes adopt similar optimal structures in a variety of cases. Additionally, they found that there are certain numbers of particles, or magic numbers, of a given shape that correspond to particularly high cluster densities. Their work appears in the Proceedings of the National Academy of Sciences.Their initial studies compared the densest packed clusters of each of the Platonic solids with clusters of spheres. Cluster packing can occur in various geometries and layers. Similarity to sphere cluster packing was determined using mathematical methods. Of the Platonic solids, the icosahedron had the greatest number of cluster geometries that matched closely to clusters of spheres, and, indeed, its three-dimensional shape is most closely spherical. The other shapes progressively decreased in similarity to sphere cluster packings with dodecahedra having several similar geometries, followed by octahedra, and then cubes. No clusters of tetrahedra were structurally similar to their corresponding cluster of spheres.Teich, et al. found that the clusters of particles that most resembled clusters of spheres typically packed in layers of optimal spherical codes, demonstrating the influence of the container shape on optimal packing structure. An optimal spherical code at a particular value of N is a way of packing N spheres most tightly inside a spherical shell. Interestingly, both bulk icosahedra and dodecahedra packed in layers of optimal spherical codes in a majority of cases even though they are dual to each other, or the faces and vertices are switched on these two shapes. One would expect “opposite” packing, but instead, both adopt optimal spherical code layering, which indicates the container is more important than particle shape. Explore further (Phys.org)—Many biological systems involve dense packing of a large amount of material or particles in a confined space. For example, eukaryotes’ nuclei hold about two meters of DNA that is tightly wound into chromosomes. On the larger scale pharmaceutical packaging, manufacturing, and transport all involve trying to pack the most amount of material within a small space. Furthermore, nanotechnology and material sciences are concerned with particle packing and layering. While the concept of packing the most amount of material in a small space is simple, understanding how particles of various shapes pack is not. More information: Erin G. Teich et al. Clusters of polyhedra in spherical confinement, Proceedings of the National Academy of Sciences (2016). DOI: 10.1073/pnas.1524875113AbstractDense particle packing in a confining volume remains a rich, largely unexplored problem, despite applications in blood clotting, plasmonics, industrial packaging and transport, colloidal molecule design, and information storage. Here, we report densest found clusters of the Platonic solids in spherical confinement, for up to constituent polyhedral particles. We examine the interplay between anisotropic particle shape and isotropic 3D confinement. Densest clusters exhibit a wide variety of symmetry point groups and form in up to three layers at higher N. For many N values, icosahedra and dodecahedra form clusters that resemble sphere clusters. These common structures are layers of optimal spherical codes in most cases, a surprising fact given the significant faceting of the icosahedron and dodecahedron. We also investigate cluster density as a function of N for each particle shape. We find that, in contrast to what happens in bulk, polyhedra often pack less densely than spheres. We also find especially dense clusters at so-called magic numbers of constituent particles. Our results showcase the structural diversity and experimental utility of families of solutions to the packing in confinement problem. Computational study finds maximum packing density of 55,000 different shapes Studies looking at cluster density provided several insights. First, as expected, cluster density increases as the number of particles increases until the particles approximate a spherical shape. Then, density increases much more slowly, expected to level off as the number of particles goes to infinity. Additionally, there are certain numbers of particles at which density significantly increases. These numbers differ for the different particle shapes. At these particular particle numbers, deemed magic numbers, the cluster density is larger and is greater than the cluster density for clusters with one less or one more particle.”Our results show that polyhedra adopt an incredibly diverse array of cluster structures merely when we force them to pack inside a sphere, the simplest type of three-dimensional container,” says Erin Teich, lead author of the study. “Not only are these clusters experimentally relevant, but they also demonstrate the tightly-coupled relationship between packing structure and the packing environment. This relationship has only just begun to be explored- we plan to tackle it by examining clusters formed by different particle shapes packing in a variety of confining geometries.” Teich, et al.’s results reveal that contrary the hypothetical case in infinite space, spheres are not necessarily the worst packing particle within a confined space, and unlike three-dimensional packing on in infinite space, packing within a confined space depends less on particle shape and more on the ability of the particle clusters to take on the container’s shape. Some of the cluster symmetries observed here demonstrate optimal density and packing within a particular confined space, which has implications for analogous biological and material systems. © 2016 Phys.org This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. 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Egyptian mummies found to have oldest figurative tattoos

first_imgCredit: British Museum A team of researchers from across Europe has found tattoos on two mummies at the British Museum, making them the oldest known examples of figurative tattoos. In their paper published in Journal of Archaeological Science, the group describes their study of dark splotches on preserved mummy skin. New tattoos discovered on Oetzi mummy More information: Renée Friedman et al. Natural mummies from Predynastic Egypt reveal the world’s earliest figural tattoos, Journal of Archaeological Science (2018). DOI: 10.1016/j.jas.2018.02.002 Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.center_img Two mummies, one male, the other female, housed in the British Museum, were discovered over a century ago in Gebelein, a city that once existed in ancient Egypt—they have become part of a popular collection that is open to the public. In this new effort, the researchers were interested in dark splotches on the preserved skin. When they shined infrared light on the blotches, they observed distinct images.The team reports that the light revealed the outline of a Barbary sheep and a wild bull with horns on the upper arm of the male, and S-shaped designs and, on the shoulder of the female, a motif resembling the batons used in rituals. A closer look showed that the outlines were under the skin, and were likely made using soot from a fire, probably with a needle made from copper or bone.The record for the oldest tattoo is held by Ötzi the Iceman, but his tattoos were all geometric shapes. The images on the two mummies in the museum depict actual objects or beings, making them figurative, and are the oldest known example of such tattoos at 5000 years, breaking the old record by a thousand years.In addition to setting a record for tattoos, the finding also shows that archaeologists have been wrong in assuming that only women at the time were tattooed. The different types of tattoos also provide hints as to their purpose. Strong animals with horns likely communicated strength and bravery. The batons on the female, on the other hand, were generally used by women during rituals, and tattooing them on the skin likely represented an extension of that function. The researchers suggest that tattooing in the ancient culture was likely also a means for advertising status or other attributes. © 2018 Phys.org Journal information: Journal of Archaeological Science Citation: Egyptian mummies found to have oldest figurative tattoos (2018, March 2) retrieved 18 August 2019 from https://phys.org/news/2018-03-egyptian-mummies-oldest-figurative-tattoos.htmllast_img read more

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A possible explanation for varying measurements of Venuss rotation rate

first_img © 2018 Phys.org A trio of researchers with the University of California and Sorbonne Universités has found a possible explanation for why Venus probes have found different day lengths for the planet. In their paper published in the journal Nature Geoscience, T. Navarro, G. Schubert and S. Lebonnois describe a theory they have developed based on observational data. Explore further Credit: CC0 Public Domain Image: Cloudy Venus More information: T. Navarro et al. Atmospheric mountain wave generation on Venus and its influence on the solid planet’s rotation rate, Nature Geoscience (2018). DOI: 10.1038/s41561-018-0157-xAbstractThe Akatsuki spacecraft observed a 10,000-km-long meridional structure at the top of the cloud deck of Venus that appeared stationary with respect to the surface and was interpreted as a gravity wave. Additionally, over four Venus solar days of observations, other such waves were observed to appear in the afternoon over equatorial highland regions. This indicates a direct influence of the solid planet on the whole Venusian atmosphere despite dissimilar rotation rates of 243 and 4 days, respectively. How such gravity waves might be generated on Venus is not understood. Here, we use general circulation model simulations of the Venusian atmosphere to show that the observations are consistent with stationary gravity waves over topographic highs—or mountain waves—that are generated in the afternoon in equatorial regions by the diurnal cycle of near-surface atmospheric stability. We find that these mountain waves substantially contribute to the total atmospheric torque that acts on the planet’s surface. We estimate that mountain waves, along with the thermal tide and baroclinic waves, can produce a change in the rotation rate of the solid body of about 2 minutes per solar day. This interplay between the solid planet and atmosphere may explain some of the difference in rotation rates (equivalent to a change in the length of day of about 7 minutes) measured by spacecraft over the past 40 years.center_img Journal information: Nature Geoscience Citation: A possible explanation for varying measurements of Venus’s rotation rate (2018, June 20) retrieved 18 August 2019 from https://phys.org/news/2018-06-explanation-varying-venus-rotation.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Measurements of the rotation speed of Venus have varied over the years for unknown reasons. It is known that it takes 243 Earth days for the planet to spin just once, but exact measurements have varied by an average of seven minutes. Prior research has also shown that the atmosphere circulates around the planet much faster—getting all the way around in just four Earth days. In this new effort, the researchers suggest they might have found at least one of the characteristics causing the planet to spin at variable speeds, and it has to do with atmospheric circulation.The researchers started with a long-standing wave that has been observed in Venus’s cloud formations—a wave approximately 10,000 kilometers long. They noted that similar waves have been seen on Earth, due to air colliding with mountains, but those typically dissipate rapidly due to air currents. But the atmosphere on Venus is notably thicker than on Earth, an observation that intrigued the researchers. They created a simulation to recreate the cloud formations seen on Venus and introduced the idea of mountains on the surface as the cause. After adding in all known ingredients in Venus’s atmosphere and accounting for the planet’s size and density, they finished by adding mountains on the surface. They then ran the simulation.The researchers report that the simulation did show a wave formed in the cloud tops, similar to that seen on the actual planet. But they also found that the braking effect caused by the atmosphere running into the mountains actually slowed the spin of the planet—the amount depended on the time of day. They found that on average, though, the effect was enough to cause up to two minutes of variation in planet spin speed—not enough to account for the observed seven minutes of variability, but enough to suggest other physical features could be playing a similar role.last_img read more

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When Employees Feel Grateful Theyre Less Likely to Be Dishonest

first_imgDishonesty in the workplace can be a major problem for any business. Recent estimates suggest that theft and fraud by employees reduce the profits of U.S. businesses by $50 billion annually. And to make matters worse, the problem is growing. The Association of Certified Fraud Examiners noted that non-cash thefts in workplaces increased over 10% from 2002 to 2018. — My colleagues and I, however, believe that there might be a different way to address the problem — one that works from the “bottom-up.” What I mean by this is a strategy that doesn’t rely on people remembering to try to control selfish impulses, but rather one that automatically strengthens’ people’s ability to resist temptation. Since our past work had revealed that feelings of gratitude work in just this way — that they effortlessly enhance patience and self-control — we wanted to see if gratitude would also reduce dishonest behavior. The toll, however, isn’t just a financial one. Working in an environment with unethical peers not only can cause stress, but also can lead honest employees to either leave the company or begin to adopt unethical norms for themselves, thereby exacerbating the effects on a corporation’s culture. To examine this question, we conducted two experiments, the results of which will be published in the journal Psychological Science. In one of these experiments, we asked 141 people to participate in an online study using Amazon MTurk that purportedly examined different types of memories. To induce appropriate emotional states, we randomly assigned each person to write about a time they felt grateful, a time they felt happy and amused, or about the events of their typical day (i.e., a neutral memory). Read the whole story: Harvard Business Reviewlast_img read more

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Traditions at heart

first_imgThe Capital can feel and  enjoy the essence of the Punjabi music and culture as the Festival of Traditional Music of Punjab is ready to go live. Punjabi Aademy, Dept. of Art and Culture, Delhi Govt. brings us the two days Punjabi Kheyal Bandishes (compositions) and Thumri and Sufiana Kalaam. The audience will indulge into the mood by the melodious renditions of veteran singers like  Ustad Mazhar Ali Khan and Jawad Ali Khan, Baljeet Singh Namdhari among others. Also Read – ‘Playing Jojo was emotionally exhausting’The opening day of the festival (30 May) will feature Baljeet Singh Namdhari and  Pt Somdutt Battu. Ud Jawad Ali Khan, Ud Mazhar Ali Khan and Alankar Singh will be closing the festival on the following day (31 May).Mazhar Ali is a Hindustani classical vocalist of the Patiala Gharana, known for his performances of dadra and thumri. He has performed in India, Pakistan, and North America. He is the grandson of the doyen of the Patiala Gharana, Ustad Bade Ghulam Ali Khan. Jawad Ali is the brother of Mazhaar Ali and vocalist of Kasur Patiala Gharana. He started his musical career in the early 80’s. He is also a vocalist of All India Radio. He has performed at almost every music conference of India with his brother Mazhaar.  Also Read – Leslie doing new comedy special with NetflixTalking about Punjabi Academy, Delhi, after independence it emerged as a cosmopolitan city of diverse cultures and languages. It has always been the endeavor of the Delhi Administration to provide all possible facilities for the development and promotion of different languages and projection of the composite culture of Delhi. Ever since its inception the Academy has been playing a catalytic role in the proliferation of Punjabi literary and cultural activities in the spheres of music, folk dances, seminars, symposia, short story, poetry, novel, literary criticism, drama etc. During the last two decades, the Academy has assumed a significant role and status of premier organization in the field of Punjabi language, literature and culture.When: 30 –31 May, 6.30 pm onwardsWhere: Indian International Centrelast_img read more

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Flagging off

first_imgDharmendra Pradhan, Minister of State (Independent Charge) for Petroleum & Natural Gas flagged off the IndianOil sponsored Spirit of Freedom- adventure for social outreach, motorbike expedition of Pathfinders to Ladakh today in the presence of B Ashok, Chairman, Indian Oil Corporation Limited.Addressing the Pathfinders group and the gathering at the flag off ceremony of the bikers rally, Dharmendra Pradhan, MoS (Incharge) for Petroleum & Natural Gas urged the audience to observe a minute’s silence to pay homage to the people who lost their lives in the recent floods in Jammu & Kashmir. The people living in mountainous regions face many hardships and each day is a test of survival for them. Also Read – ‘Playing Jojo was emotionally exhausting’The ongoing natural disaster in Jammu & Kashmir (J&K) is a cause of concern and the government is taking all possible measures to provide relief to the victims. He also mentioned that the challenge today is to manage mountain regions in a sustainable manner so as to avoid degradation and subsequent increase in poverty and hunger in these regions.The minister said that IndianOil is currently supporting and making all possible arrangements to ensure the supply of petroleum products in the flood affected areas of J&K. Pradhan informed the gathering that the Prime Minister has announced a relief fund of Rupees One Thousand Crore for the flood victims of J&K and the utilization of the fund is being monitored on daily basis. He also said that the Prime Minister has advised every  ministry to extend support to the flood victims of J&K and render all possible support to bring life back on track in the affected areas. Also Read – Leslie doing new comedy special with NetflixWhile addressing the audience, B Ashok, Chairman, IndianOil lauded the efforts of the Pathfinders which promises to make a difference to the people living in remote Himalayan region. Talking about the crisis in J&K, Ashok mentioned that IndianOil has also ensured supply of petroleum products like petrol, diesel, cooking gas etc. in the region.This year the expedition would visit Chushul, a valley in Ladakh as well as Turtuk village which is at the extreme corner of the Indian border whose accessibility is a challenge. A troop of 7 bikes with 15 members would roughly cover 3500 Kms in a span of 15 days in the trans Himalayan region of India. The expedition aims to spread awareness about environment degradation in the Himalayas among the school children in the remote villages of Ladakh as well as to reach out to the underprivileged in these inaccessible and hilly areas.last_img read more

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