first_img Explore further Citation: Fabricating 3D Photonic Crystals (2009, January 21) retrieved 18 August 2019 from https://phys.org/news/2009-01-fabricating-3d-photonic-crystals.html (PhysOrg.com) — “In photonic crystals, the ability to control the structure of a material in full three dimensional space, allows you to control the way that light flows through it,” John Rogers tells PhysOrg.com. “This approach to photonic materials can be useful in applications ranging from communications to lasers to optical waveguides.” Rogers, a scientist at the University of Illinois at Urbana-Champaign, and his colleagues at the University of Illinois and a team from Sandia National Laboratories in Albuquerque, New Mexico, have developed a simple technique that allows for the fabrication of silicon photonic crystals in 3-D. Their process is described in Applied Physics Letters: “Three dimensional silicon photonic crystals fabricated by two photon phase mask lithography.”“Theoretical studies of idealized structures of this general type suggest their promise for manipulating of the flow of light through devices,” Rogers continues, “but from a practical standpoint, the fabrication has been difficult. Often, these crystals are patterned in a two dimensional plane defined by a silicon wafer. If you want something three dimensional, you stack them up to form a thin structure that has some level of 3D character. Unfortunately, with this method, you have more steps, making it more involved and expensive.”The team from the University of Illinois and Sandia decided to use phase mask lithography to create a full three dimensional silicon photonic crystal from the outset. Silicon is used because it has a high index of refraction, making it ideal for applications that make use of light. “The technique we’ve achieved is the culmination of six years of work as we tried to figure out how to optimize this process.”In order to create 3-D photonic crystals, the team used rubber optical elements and a specially prepared polymer. Using a laser, it is possible to create a pattern out of the polymer to define the crystal geometry of the crystal – a mold. Next, Rogers said, the three dimensional structure mold was used as a template. “We grew silicon on the polymer template, similar to what is done in two dimensions in the microelectronics industry.” Finally, the polymer template is burned away, leaving the silicon photonic crystal behind.“One of the key aspects of this fabrication process is that it is scalable,” Rogers says. “Not only are we facilitating patterning up front, but we’re also talking about a process that we can do over large areas, such as a square meter. In addition, it has the advantage of being adaptable to technology that already exists.”The ability to create silicon photonic crystals that are larger, using a process that is less expensive and elaborate than what is normally used, offers some potential for applications dealing with light. Rogers points out that this fabrication process would be useful for reflective (or even anti-reflective) coatings, creating optical diodes and even accomplishing high speed data routing. He even sees potential to adapt the process to work on a micro level, integrating these types of techniques with electronics. “There are a number of applications that could benefit from this fabrication process, since it offers high quality, low-cost photonic crystals.”More information: Shir, D., et. al. “Three dimensional silicon photonic crystals fabricated by two photon phase mask lithography.” Applied Physics Letters (2009). Available online: link.aip.org/link/?APPLAB/94/011101/1 . 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.center_img 2-D crystals conforming to 3-D curves create strain for engineering quantum devices 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

first_img“The Dirac monopole is conceptually the simplest model for a magnetic point charge (i.e. a magnetic monopole) and this makes the Dirac monopole important,” Pietilä said. “Monopoles in general can be any point-like defects in a three-component vector field defined in three spatial dimensions, but they are not necessarily associated with a singular filament (the Dirac string).”Through modeling, Pietilä and Möttönen theoretically demonstrate that the Dirac string can be split into two parts by modifying the external magnetic field, which breaks the rotation symmetry of the system. In this case, state-of-the-art experimental methods that measure changes in particle density and spin density could be used to detect a signature of the monopole. In addition, in spin-1 BEC, the spin texture is topologically unstable, allowing it to be removed. Through simulations, the scientists show that removing the monopole could be done by turning off the external magnetic fields. The monopole “unwinds” itself along the Dirac string and leaves behind a closed vortex ring. The speed of the unwinding depends on how quickly or gradually the magnetic field is turned off.The existence of magnetic monopoles has far-reaching implications for many research areas, including the laws of quantum mechanics, theories of elementary particles, and cosmology. Experimentally confirming the existence of monopoles would provide long-sought evidence for some ideas, and possibly open up the doors to other new ones.“The existence of magnetic monopoles implies that the electric charge has to be quantized (that is, it can only appear as an integral multiple of the elementary charge),” Pietilä said. “Existence of magnetic monopoles has also certain cosmological implications. Since monopoles in general are related to the spontaneous symmetry breaking, they impact the unified theories describing the interactions between the elementary particles. In the context of condensed matter physics, monopoles typically arise as a manifestation of some exotic collective behavior of matter and can be used to explain the unusual characteristics of such systems.”More information: Ville Pietilä and Mikko Möttönen. “Creation of Dirac Monopoles in Spinor Bose-Einstein Condensates.” Physical Review Letters 103, 030401 (2009). link.aps.org/doi/10.1103/PhysRevLett.103.030401Copyright 2009 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. 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. (PhysOrg.com) — For decades, scientists have been intrigued by the hypothetical existence of magnetic monopoles – particles with only a north or south magnetic pole, thus having a nonzero magnetic charge. But while modern theories predict their existence, monopoles have not yet been experimentally observed, despite numerous attempts. Recently, physicists have introduced a new method to create analogies to magnetic monopoles, and predict that they could be observed with current technology. Possible configurations for the spin texture of a Bose-Einstein condensate. These defects give rise to a vorticity field that is equivalent to the magnetic field of a magnetic monopole. Credit: Pietilä and Möttönen. Explore furthercenter_img Citation: Physicists Propose a Method to Observe Dirac Monopoles (2009, July 28) retrieved 18 August 2019 from https://phys.org/news/2009-07-physicists-method-dirac-monopoles.html Ville Pietilä and Mikko Möttönen, both of the Helsinki University of Technology in Finland and the University of New South Wales in Australia, have published their theoretical demonstration in a recent issue of Physical Review Letters. Here, they explain how applying an external magnetic field to a Bose-Einstein condensate (BEC) – a large group of cold atoms that exhibits coherent quantum properties – can create point-like topological defects on the spin texture of the BEC. These defects give rise to a vorticity field that is essentially equivalent to the magnetic field of a magnetic monopole.“Since all experimental attempts to find magnetic monopoles have proven to be futile, there is no experimental evidence supporting the existence of magnetic monopoles,” Pietilä told PhysOrg.com. “Other types of monopoles without the Dirac string have been realized in experiments already in the early ‘90s in liquid crystals. An analogy of the real space magnetic monopole was reported to occur in the crystal momentum space of a metallic ferromagnet, but the experimental evidence in this case is somewhat indirect. Dirac monopoles in the more general settings are predicted to occur in various systems such as superfluid Helium-3 and dilute spin-1 Bose-Einstein condensate but so far there are no (direct) experimental observations although they may have been present in some of the Helium-3 experiments. There is also a very recent suggestion on how to induce a magnetic monopole to a band insulator.“Since magnetic monopoles have never been observed, it is pertinent to ask whether there is something unphysical in the whole concept,” he continued. “Our work shows that at least the Dirac monopole can be realized experimentally, thus indicating that it is more than just a theoretical curiosity. However, it should be stressed that our work does not tell anything about the existence of magnetic monopoles in the electromagnetic field.”Pietilä and Möttönen predict that it should be possible to design an experiment to detect the monopole in this situation, if it does exist. As they explain, the magnetic field of the monopole is provided by a Dirac string, which is a line extending from the monopole to infinity. The Dirac string explains why the monopole charge comes in discrete quanta. Since the Dirac string carries two quanta of angular momentum, it is expected to be prone to splitting into two separate strings, each carrying a single quantum. Making magnetic monopoles, and other exotica, in the lablast_img read more

first_img Explore further Citation: Intel’s Atom CE 4100 SoC Will Transform Internet TV (w/ Video) (2009, September 25) retrieved 18 August 2019 from https://phys.org/news/2009-09-intel-atom-ce-soc-internet.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. Dell Talking About 80-Core Chip Processor The new Atom processor is part of Intel’s new family of media processors. Formerly codenamed “Sodaville,” the new chip is the first 45nm-based System-on-Chip to be designed on Intel’s architecture.The CE4100 replaces Intel’s former CE 3100 processor which is an older Pentium core processor. Intel’s newest Atom processor core is expected to reach speeds of about 1.2GHz and offer support for a range of industry standards. Intel is also teaming up with Adobe to provide support for the Adobe Flash Player 10 on Intel’s family of CE media processors. The new CE4100 SoC also provides MPEG-4 support, 3D graphics capability, high-end audio and can also capture uncompressed 1080p video. (PhysOrg.com) — At the IDF event, in Santa Clara, California, Intel announced the debut of their newest System-on-Chip (SoC), the Intel Atom processor CE4100. The CE4100 SoC is designed exclusively to facilitate Internet content and other services to digital TVs, Blu-ray players and other entertainment devices. At the IDF event, in Santa Clara, California, Intel’s Eric Kim (Sr. VP of Intel Corporation’s Digital Home Group) commented: “The architecture of Intel media processors provides a powerful and innovative platform to showcase Flash-based applications in a vivid way. Flash Player 10 combined with the performance of the Intel media processor and its support for standards such as OpenGL ES 2.0 offers a compelling environment for Flash-based games, videos and other rich Web content and applications.”The chip also features an integrated NAND controller, along with support for DDR2 and DDR3 memory, which will provide a choice to developers of digital TVs and set-top boxes. It is not certain when the Atom CE4100-based devices will reach the market, however Intel has promised some hardware demos from its partners.© 2009 PhysOrg.comlast_img read more

first_img Explore further More information: Patent: appft1.uspto.gov/netacgi/nph-P … 45&RS=DN/20120188245AbstractThere are provided apparatuses and methods for increasing the pixel density of a digital display through mechanical actuation. In some embodiments, a display device is described having a processor configured to provide an image for display and a memory coupled to the processor. The memory stores the image and is configured to map the image to a pixel matrix. A display controller is coupled to the memory and configured to sample portions of the image and to store the portions of the image into planes. Each sampled portion comprises a different set of pixels of the pixel matrix. A display is coupled to the display controller and is configured to display the contents of the sampled planes. In particular, the display controller is configured to sequentially provide the sampled planes to the display for sequential display. At least one actuator is coupled to the display to displace the display for the displaying of the sampled planes, so that pixels of each plane are displayed in a unique location from the pixels of other planes.via: www.patentlyapple.com/patently … e-video-glasses.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. © 2012 Phys.org Citation: Apple bowl-headed patent shows wearable computing plans (2012, July 29) retrieved 18 August 2019 from https://phys.org/news/2012-07-apple-bowl-headed-patent-wearable.htmlcenter_img (Phys.org) — Like Google, Apple has plans to win recognition as wearable computing leaders. Patently Apple reports on a patent that was filed by Apple in January last year but made known earlier this week. The patent application is causing a stir over what Apple has in mind to compete with Google over the latter’s highly anticipated Project Glass heads-up display. The Apple patent in question, titled “Display resolution increase with mechanical actuation,” speaks of multiple “embodiments,” but the concept appears to relate to raising the quality of a display placed over a wearer’s eye. The patent drawings show a very odd-looking bowl over a person’s head extending out to eyewear over just one eye. The implication beyond the obtuse patent text is clear that Apple is fixed on competing with Google for the coming generation of heads-up display wearers, and, in competing, is to use its key ammunition, its own brand recognition that Apple provides high quality visuals whether on its desktop, tablet, phone or, now possibly, on video glasses. The inventor is listed on the patent application as Edward Craig Hyatt.Those bloggers watching Apple and writing about the patent news agree that the text is obtuse, ambitiously general, and hard to pin down, as a patent application for ideas that could take any form of multiple “embodiments.” Nonetheless, it can be said that the goal of Apple seems to be to improve the resolution of images seen through a head-mounted display.According to the patent application, “There are provided apparatuses and methods for increasing the pixel density of a digital display through mechanical actuation. In some embodiments, a display device is described having a processor configured to provide an image for display and a memory coupled to the processor. The memory stores the image and is configured to map the image to a pixel matrix. A display controller is coupled to the memory and configured to sample portions of the image and to store the portions of the image into planes. Each sampled portion comprises a different set of pixels of the pixel matrix. A display is coupled to the display controller and is configured to display the contents of the sampled planes. In particular, the display controller is configured to sequentially provide the sampled planes to the display for sequential display. At least one actuator is coupled to the display to displace the display for the displaying of the sampled planes, so that pixels of each plane are displayed in a unique location from the pixels of other planes.” Google patent sends ring signals to Project Glasslast_img read more

first_img Explore further More information: The gravity tunnel in a non-uniform Earth, Am. J. Phys. 83, 231 (2015); dx.doi.org/10.1119/1.4898780 . On Arxiv: arxiv.org/abs/1308.1342AbstractThis paper examines the gravity tunnel using the internal structure of Earth as ascertained from seismic data. Numerically, it is found that the time taken to fall along the diameter is 38 min, compared to 42 min for a planet with uniform density. The time taken to fall along a straight line between any two points is no longer independent of distance but interpolates between 42 min for short trips and 38 min for long trips. The brachistochrone path (minimizing the time between any two points) is similar in shape to the uniform-density solution but tends to reach a greater maximum depth and takes less time to traverse. Although the assumption of uniform density works well in many cases, the simpler assumption of a constant gravitational field serves as a better approximation to the true results. Are astronauts really weightless? A composite image of the Western hemisphere of the Earth. Credit: NASA (Phys.org)—Alexander Klotz a student at McGill University in Canada has calculated a new answer to the commonly asked physics question, how long would it take a person to fall all the way through the Earth? Instead of the commonly accepted 42 minutes, he claims it is 38. He has published his reasoning, math and conclusions in a paper published in The American Journal of Physics. © 2015 Phys.org Journal information: American Journal of Physicscenter_img If someone were to drill a hole all the way through the planet, and then somehow manage to fall into it, how long would it take them to arrive on the other side? That is a physics question put to students every year, and those who give it expect the answer to be 42 minutes. But is that answer correct? Klotz says no and has the math to prove it, Science reported.The accepted answer of 42 minutes takes into account the constantly changing impact that gravity will have (and ignoring drag due to the presence of air) on the person falling, becoming less and less of a factor as the center of the Earth is approached then growing stronger and stronger as the person heads “up” against gravity on the other side. It is accepted that the speed attained during the descent on the first half of the journey would be significant enough to cause the person to continue moving against gravity on the other side of the planet, right up until the surface is reached.But Klotz argues that it is time to start taking the different densities of the Earth’s layers into consideration—after all, a lot of research has shown that our planet is a lot denser at the center than at the crust for example—and that of course would have an impact on the person falling through. He has used seismic data to calculate the different densities at different depths and has used that data to give a more accurate answer to the falling man question, stating that it would in fact, take just 38 minutes (and 11 seconds) to fall all the way through, not 42 and (12 seconds).Interestingly, Klotz also notes that if gravity were to be assumed to be at a surface level constant throughout the duration of the trip, the math shows it would take just 38 minutes as well. , Science , arXiv Citation: New way to calculate how long it would take to fall through a hole in the Earth (2015, March 26) retrieved 18 August 2019 from https://phys.org/news/2015-03-fall-hole-earth.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.last_img read more

first_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. Citation: Best of Last Week –A radiationless revolution, progress towards a fusion reactor and neuroticism’s link to over-thinking (2015, August 31) retrieved 18 August 2019 from https://phys.org/news/2015-08-week-radiationless-revolution-fusion-reactor.html © 2015 Phys.org Explore further Tri Alpha Energy reportedly makes important breakthrough in developing fusion reactorcenter_img (Phys.org)—It has been another good week for physics as a team working at the CERN complex found evidence that suggests subatomic particles could defy the standard model—they found tau leptons and muons decaying at different rates. Also, another team at the Australian National University announced a new theory that could lead to a radiationless revolution—it describes a way to confine electromagnetic energy without leakage. And Matthew Fisher with the University of California proposed the idea of quantum cognition based on synaptic nuclear spins, i.e. neural qubits. His idea is that quantum processing with nuclear spins might be happening in the brain. Also, a company called Tri Alpha Energy reportedly made an important breakthrough in developing a fusion reactor—they found a way to hold a ball of superheated hydrogen plasma for five milliseconds. The news from space was good as well, as NASA announced that the New Horizons mission exceeded expectations—sending back images of Pluto and its moons along with a host of other valuable scientific data. Also, another team of astrophysicists found supermassive black holes in the quasar nearest Earth—within Galaxy Markarian 231, they discovered has two black holes spinning around each other.In other news, researchers working at Los Alamos National Laboratory announced that they had created quantum dot solar windows that go non-toxic and colorless, all with record efficiency—the windows capture some of the light that passes through the glass and divert it to solar cells at the edges. And a team of researchers at the University of Toronto announced that they had developed a new “tissue Velcro” that could help repair damaged hearts—it is a scaffolding upon which new heart muscle can grow. Also, another team working at MIT created a new printer called “Multifab” that 3D-prints a record 10 materials at once with no assembly required. It has a resolution of 40 microns and is the first 3D printer to use 3D scanning techniques from machine vision.And finally, if you have ever been accused of being neurotic, a small team of psychologists with King’s College in London and Columbia University in the U.S. asked the question: Is neuroticism fueled by overthinking? And they think they have found why creativity and neurosis-related unhappiness and go hand-in-hand—the same parts of the brain appear to be involved in both. In this event display from the LHCb experiment at CERN’s Large Hadron Collider, proton-proton collisions at the interaction point (far left) result in a shower of leptons and other charged particles. The yellow and green lines are computer-generated reconstructions of the particles’ trajectories through the layers of the LHCb detector. Credit: CERN/LHCb Collaborationlast_img read more

first_img Explore further More information: A comprehensive phylogeny of birds (Aves) using targeted next-generation DNA sequencing, Nature (2015) DOI: 10.1038/nature15697AbstractAlthough reconstruction of the phylogeny of living birds has progressed tremendously in the last decade, the evolutionary history of Neoaves—a clade that encompasses nearly all living bird species—remains the greatest unresolved challenge in dinosaur systematics. Here we investigate avian phylogeny with an unprecedented scale of data: >390,000 bases of genomic sequence data from each of 198 species of living birds, representing all major avian lineages, and two crocodilian outgroups. Sequence data were collected using anchored hybrid enrichment, yielding 259 nuclear loci with an average length of 1,523 bases for a total data set of over 7.8 × 107 bases. Bayesian and maximum likelihood analyses yielded highly supported and nearly identical phylogenetic trees for all major avian lineages. Five major clades form successive sister groups to the rest of Neoaves: (1) a clade including nightjars, other caprimulgiforms, swifts, and hummingbirds; (2) a clade uniting cuckoos, bustards, and turacos with pigeons, mesites, and sandgrouse; (3) cranes and their relatives; (4) a comprehensive waterbird clade, including all diving, wading, and shorebirds; and (5) a comprehensive landbird clade with the enigmatic hoatzin (Opisthocomus hoazin) as the sister group to the rest. Neither of the two main, recently proposed Neoavian clades—Columbea and Passerea1—were supported as monophyletic. The results of our divergence time analyses are congruent with the palaeontological record, supporting a major radiation of crown birds in the wake of the Cretaceous–Palaeogene (K–Pg) mass extinction. Citation: Group builds most comprehensive family tree of birds to date (2015, October 8) retrieved 18 August 2019 from https://phys.org/news/2015-10-group-comprehensive-family-tree-birds.html Building a family tree for modern birds has been difficult for scientists because of the dearth of fossil evidence going past 66 million years—the time before the mass extinction that wiped out the other dinosaurs. After the extinction, bird species evolved so rapidly that it has been difficult to use traditional genomic techniques to follow the paths of the evolution of new species, which in turn has made it almost impossible to create an accurate tree. To overcome such problems the researchers with this latest effort used a different type of genomic sequencing technique—it is called anchored hybrid enrichment and allows for sampling parts of the genome that evolved both slowly and more quickly in the flanking regions.In all the team collected and tested samples from 198 bird species (which included 390,000 bases of genomic sequence data) that together represented approximately 90 percent of all known birds—a group known collectively as Neoaves. In looking at the data they retrieved, the team found that virtually all birds (excluding flightless and some chickens and ducks) could be grouped into five sub-groups, i.e. major clads. They also found evidence that suggested that all modern birds likely evolved from a single ancestor, one that lived approximately 75 million years ago, or ten million years before all the other dinosaurs went extinct—birds in general are believed to have evolved from the dinosaur family, developing feathers approximately 150 million years ago.In addition, the researchers claim their results show (and agree with paleontology records) that there was a major radiation event following the mass extinction. Dinosaur family tree gives fresh insight into rapid rise of birds (Phys.org)—A team of researchers from several institutions in the U.S. has created the most comprehensive family tree of birds to date. In their paper published in the journal Nature the team describes the genomic sequencing technique they used and the structure of the tree they created. Gavin Thomas with the University of Sheffield, in the U.K. offers a News & Views piece on the work done by the team in the same issue, highlighting differences in phylogeny between this newer work and that conducted by another team last year.center_img House finchnigel. Credit: Wikimedia Commons © 2015 Phys.org Journal information: Nature 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

first_img More information: Dhagash Mehta et al. “Kinetic Transition Networks for the Thomson Problem and Smale’s Seventh Problem.” Physical Review Letters. DOI: 10.1103/PhysRevLett.117.028301 , Also at arXiv:1605.08459 [cond-mat.soft] This puzzle is the essence of Thomson’s problem, which asks how to arrange equal charges (such as electrons) on the surface of a sphere in a way that minimizes their electrostatic potential energy—the energy caused by all of the electrons repelling each other. According to Coulomb’s law, the total energy is inversely related to the sum of the distances between all possible pairs of charges, so the goal is to spread the charges as far apart as possible.This task is more difficult than it sounds—Thomson’s problem has been rigorously solved only for numbers of 2, 3, 4, 6, and 12 charges. In 1998, mathematician Steven Smale identified the problem of how to choose starting points close to the lowest-energy state (which makes it easier to solve Thomson’s problem) as the seventh problem on his list of 18 unsolved problems for the 21st century. Part of the reason why Thomson’s problem is so important is because its applications are so far-reaching. In 1904, J.J. Thomson originally proposed the model of charges on a sphere to describe the structure of an atom. Even though experiments disproved this “plum pudding model” long ago, the Thomson problem still has notable applications in chemistry (for understanding how electrons fill electron shells in atoms), biology (for determining the arrangements of proteins on the shells of spherical viruses), as well as in physics, computer science, and such practical applications as determining the optimal placement of communication satellites around the Earth. Spheres on treesNow in a new paper published in Physical Review Letters, a team of mathematicians, engineers, and scientists from the US, the UK, and Australia has taken a new approach to Thomson’s problem that makes it much easier to determine the lowest-energy configuration. For seven numbers of charges (every third number from 132 to 150), they have constructed tree-shaped disconnectivity graphs, where the vertical axis or “trunk” corresponds to the energy of a particular charge arrangement. Each “branch” terminates at a local minimum, which are the states that have lower energies than all of their neighboring states, and so they are candidates for the ultimate lowest energy state, the global minimum. By visualizing the problem in this way, the researchers noticed that these particular graphs don’t have lots of branches extending from lots of other branches. Instead, every branch connects to only a few other branches and then to the trunk at regularly spaced energy thresholds, so that the graph resembles a palm tree or single funnel structure.The researchers found that this “funneled potential energy landscape” is characteristic of a highly ordered structure and displays characteristics of a small-world network. As a result, it provides an important clue for finding the global minimum. It tells the researchers to start their optimization algorithms using the local minima because, in these networks, it turns out that every local minimum is always within 5-7 steps (branches) of the global minimum. This is true even for local minima that have much higher energies than the global minimum, and even when the total number of local minima is very large. (Phys.org)—How do you arrange a group of points on the surface of a sphere so that all the points are as far apart from each other as possible? With two points, the answer is easy: place them on opposite sides of the sphere, as if they are endpoints of the diameter. With three points, make them the vertices of an equilateral triangle, and so on. But as the number of points increases, so does the difficulty of the problem. By visualizing the problem from a new perspective, the researchers found that lower-energy configurations have more connections than higher-energy configurations do. Credit: Mehta et al. ©2016 American Physical Society Journal information: Physical Review Letters 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. Spin glass physics with trapped ions © 2016 Phys.org The disconnectivity graph for 147 charges on a sphere has a structure-seeking “palm tree” organization. The five lowest minimum energy configurations are shown. Credit: Mehta et al. ©2016 American Physical Society Citation: Researchers chip away at Smale’s 7th unsolved problem in mathematics (2016, July 15) retrieved 18 August 2019 from https://phys.org/news/2016-07-chip-smale-7th-unsolved-problem.html The disconnectivity graph reveals other information, such as that lower-energy local minima have more connections to other states than do higher-energy local minima. The researchers also discovered that the global minimum is always the most highly connected node in the entire network, making it the network’s central node. Implications for Thomson’s and Smale’s problemsUsing this insight from the network’s single-funneled, small-world structure, finding the global minimum for Thomson’s problem becomes much easier than before.”Our work looks at Smale’s seventh problem from a completely different perspective and sheds novel light on it,” coauthor Dhagash Mehta, at the University of Notre Dame and the University of Adelaide, told Phys.org. “In this work, methods developed by the theoretical chemistry community have helped understand a deep mathematical problem. Often it is the other way around.”As the researchers explain, it’s easier to solve Thomson’s problem in these particular cases than it is to solve Smale’s problem (of choosing good starting points). So although the results will likely be useful, they do not go very far toward solving Smale’s seventh problem.”I think ‘chip away’ is about right,” said coauthor David Wales at University Chemical Laboratories in Cambridge, UK. “There is no rigorous mathematical progress on the problem from an analytic point of view.”In the future, the researchers plan to extend this approach to larger numbers of charges. From earlier work, they expect that landscapes with more than 400 charges will start to display multiple funnels, so the small-world structure may disappear. “While we have only shown data for seven numbers, we have strong reasons to believe that the single funnel is a feature for numbers less than 150,” said coauthor Halim Kusumaatmaja at Durham University in Durham, UK. “For larger numbers, there will likely be multiple funnels. Nonetheless, the network analysis could still be exploited to help us quickly identify candidates for the global minimum.”Other lines of work include exploiting the small-world properties discovered here to improve other optimization algorithms and develop novel algorithms, as well as to incorporate weight and direction into these networks, which may provide additional insight into the Thomson problem.”The social network analogy for networks of minima of the Thomson problem will go further when we analyze other network properties of these networks of minima,” Mehta said. “Our results will also help in constructing novel algorithms to find the global minimum more efficiently by exploiting these network properties.” Explore furtherlast_img read more

first_imgUpgraded to an international crafts fair, the Surajkund Crafts Mela will be inaugurated by President Pranab Mukherjee on Saturday in Haryana’s Faridabad district in the National Capital Region. Surajkund has, since its inception, been quite a favourite with Delhiites. Assam will be the flavour of the fair this year. Nearly 20 countries, including SAARC (South Asian Association for Regional Cooperation) members, have confirmed their participation in the 27th edition of the fair, a state government spokesman said. Also Read – ‘Playing Jojo was emotionally exhausting’As many as 300 crafts persons, weavers, artisans, folk musicians and dancers would participate from the theme state of Karnataka, he pointed out. ‘Keeping in view the record participation of 12 countries in the last year’s mela, it has now been upgraded as International Crafts Mela. This year also, the countries that have confirmed their participation are Rwanda, Guinea, Tunisia, South Africa, Namibia, Zambia, Ethiopia, Congo and Egypt from the African continent. Also Read – Leslie doing new comedy special with Netflix‘Eurasian countries namely Turkmenistan, Kyrgyzstan and Tajikistan and SAARC nations Sri Lanka, Afghanistan, Bhutan, Bangladesh, Nepal and Pakistan would participate. Thailand and Peru would also participate,’ he added.Surajkund Mela Authority will provide 50 per cent rebate in the entry tickets to the disabled, senior citizens, serving soldiers and ex-servicemen. Freedom fighters will have free entry to the fair.The fortnight-long fair showcases traditional crafts from all over India and leading artisans.Surajkund derives its name from the ancient amphitheatre sun pool constructed here in the 10th century AD by Raja Suraj Pal, one of the Tomar chieftains, in the Aravalli mountain range.DETAILAt: Surajkund Mela Grounds, Faridabad When: 1-15 FebruaryTimings: 9.30 am to 7.30 pmlast_img read more

first_imgShe has crooned soft numbers in the past but now actor Shraddha Kapoor is ready to take her singing passion to another level as she is training in rock music for her next film Rock On 2.The 26-year-old actress made her singing debut with the unplugged version of the song Galliyan in Ek Villain and later lent her voice for Vishal Bhardwaj’s Haider.After the release of her latest film ABCD 2 she recorded the unplugged version of Bezubaan Phir Se. Also Read – A fresh blend of fameShraddha will be training professionally for the first time for the sequel of rock musical drama Rock On.“I like singing but I never trained before Rock On 2 happened. For this film I am training in rock genre,” Shraddha told a media person.The young star is “very excited” to work with actor-filmmaker Farhan Akhtar and considers him as one of the most talented people in the film industry.”I am very excited to work with Farhan. I have been a fan of his movies, his direction, his acting, his voice. He is one of the most talented, fearless and most inspiring people we have in the industry today. And I am tremendously happy about the fact that I am doing a film with him,” she said. Also Read – Martin Freeman confirms ‘Black Panther’ returnShraddha visited North East for a recce with the Rock On 2” team and has already started working on the film’s music with Farhan, who became a singing sensation after Rock On.“Farhan and I were practising a song recently. It was lovely. He is so funny and so passionate about what he does it’s just amazing,” she said.Rock On 2, the much awaited sequel to 2008 hit, will also see Arjun Rampal, Prachi Desai, Shahana Goswami reprising their roles. Director Abhishek Kapoor will not return for the sequel.The cast will begin shooting in Shillong this September and the film is slated to release next year.last_img read more

first_imgChief Minister Nitish Kumar’s tweet likening himself to ‘chandan’ (sandalwood), which remains unaffected despite snakes wrapping themselves around it, has created a flutter in poll-bound Bihar as it is being seen as directed against his ally Rashtriya Janata Dal (RJD) chief Lalu Prasad Yadav.One @SunilVChandak posed a question to Kumar on his programme “Ask Nitish” on Twitter on July 20 – “#AskNitish if you win with Laluji and the numbers are significant, how you will be able to give good development-ordinated government?”  Also Read – Need to understand why law graduate’s natural choice is not legal profession: CJIIn reply, Kumar had tweeted, “Bihar’s development is my sole agenda. Jo Rahim uttam prakriti, ka kari sakat kusang. Chandan vish vyapat nahi, lipte rahat bhujang (Bad company doesn’t affect a virtuous man, as the sandalwood tree is not affected by snakes who wriggle around it).”  Also Read – Health remains key challenge in India’s development: KovindKumar’s comments quoting 16th century poet Rahim were seen as a veiled attack on Yadav, with whose party Kumar’s JD(U) has entered into an uneasy coalition.When media asked Yadav about the tweet, the RJD chief said though he did not know the facts, it was probably directed against the BJP. “Nitish Kumar should clarify about his tweet,” he said.Interestingly, when Kumar was declared the CM candidate of the ‘secular alliance’ last month, Yadav had said he was ready to drink “poison” to crush the “cobra” of communalism in Bihar, which was seen as reflecting his discomfort at the JD(U) leader helming the coalition. Nitish will welcome PM Bihar CM Nitish Kumar on Wednesday said he would welcome PM Narendra Modi at the airport on Saturday and attend his programmes if invited by the ministries concerned. “I have no idea if my name is there in the foundation stone or not. Whatever be the case, I will go to welcome the PM during his visit here,” he said.last_img read more

first_imgKolkata: Police have arrested three persons from Sonarpur in South 24-Parganas and seized around 900 kg of banned firecrackers from them.Acting on a tip off, the police raided and arrested the trio when they were travelling in a car. They searched the car and found three large plastic bags containing banned fire crackers.Police received prior information about a car, carrying banned crackers, that will pass through Netaji Subhas Chandra Bose Road at Rajpur near Sonarpur. To get hold of them, policemen went to the spot in plainclothes. On late Sunday night, they found a car approaching and immediately started a search operation of the same. Also Read – Rain batters Kolkata, cripples normal lifeAfter finding those plastic bags, they took the three men to the police station and investigation revealed that the plastic bags contained banned firecrackers.A police officer said: “There were around 900 kg banned firecrackers in the plastic bags.”Police are now trying to get more information about the three arrested persons. They are also trying to know the purpose behind taking such a huge quantity of banned fire crackers.The police officer said that usually such a huge quantity of banned firecrackers gets seized in October and November ahead of Diwali. “Hence, it is important for us to investigate into the case to find out why did they indulge in it now,” the officer said.Police have intensified the search operations and undertaken all necessary steps to check the selling of banned firecrackers.It may be mentioned that the police and administration together have taken several steps to check selling of banned firecrackers as it leads to pollution.last_img read more

first_imgKolkata: BJP should take the blame for the “shabby arrangement” at Prime Minister Narendra Modi’s rally at Midnapore, where 90 people were injured due to collapse of a canopy, Trinamool Congress leader Saugata Roy said in the Lok Sabha.”The Prime Minister addressed the Kisan Kalyan rally in Midnapore. People were brought in from Jharkhand, Odisha. During the rally, a tent collapsed, leaving 90 people injured, of which 50 were women. BJP had organised the rally. They must take blame for the shabby arrangement,” Roy said during Zero Hour. Also Read – Rain batters Kolkata, cripples normal lifeA makeshift tent had collapsed during Modi’s rally in Midnapore on July 16, following which the Centre had sought a report from the Bengal government.The tent was erected next to the main entrance of the rally venue to shelter people from the rain and the incident had happened when the Prime Minister was mid-way through his speech.Meanwhile, a team comprising senior officials of the Ministry of Home Affairs visited the spot in connection with the incident. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedJoint Secretary Arti Bhatnagar and two senior SPG officials visited the spot after holding a detailed discussion with senior officials of the district administration and police.The police have also been looking into the role of the decorators that had erected the pandal. It may be mentioned that no fault of the Public Works Department was found with regard to the collapse, according to sources in Nabanna.It has been stated that the area was under the SPG from seven days ahead of the rally. So, the state police does not have much to do in this connection.last_img read more

first_imgKolkata: The 10th edition of Apeejay Kolkata Literary Festival will see the participation of writers, poets and dignitaries from China, Italy, France, Australia, Singapore, USA, UK and Pakistan, alongside noted names from Indian literary circles. Scheduled to take place from January 18 to 20 next year, it will feature Andrew Sean Greer, Pulitzer winner for Fiction 2018; Ira Mukhoty, known for her feminist writing; Devdutt Pattanaik, mythology expert and author; Ramchandra Guha, historian; Ravinder Singh, Young Adult author; Upamanyu Chatterjee, celebrated writer; Ravish Kumar, journalist, Poet and author; along with veteran Bollywood actor Naseeruddin Shah. Also Read – Rain batters Kolkata, cripples normal life “Apeejay Kolkata Literary Festival (AKLF) has connected, empowered and mobilised new voices and ideas since its inception in 2010. In the last nine years, the festival has contributed greatly to restoring Kolkata’s literary edge, a distinct and valued identity, I felt, at the time, it was losing. “AKLF has developed as the fountainhead of the mission we pursue 365 days at Oxford Bookstores – of books, reading, literature, writers, publishers, building readership, creating awareness and attraction for the world of books and popularising the whole gamut that goes with books and publishing,” said Priti Paul, Director, Apeejay Surrendra Group. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed Novelist of the much acclaimed “All The Lives We Never Lived” Anuradha Roy; former Jammu and Kashmir Chief Minister Farooq Abdullah; and Sahitya Akademi winner Jerry Pinto will also be participating. They will be joined by Ashwin Sanghi, Rajmohan Gandhi, Shashi Tharoor, Shobhaa De, and Ratna Pathak Shah. AKLF 2019 will focus on health, current affairs, women’s issues, and children’s literature among other themes. The 10th edition of the festival will be held in Park Street’s iconic spaces giving everyone an opportunity to (re)visit, admire and enjoy their tangible and intangible heritage.last_img read more

first_imgKolkata: The Calcutta High Court on Friday refused to stay the election for the Mayoral post in Kolkata Municipal Corporation, which will be held on Monday, December 3. KMC chairperson Mala Roy held a meeting with the councillors and urged them to be present for the voting and use their democratic rights. 114 out of 122 elected councillors of Trinamool Congress attended the meeting.It may be mentioned that Firhad Hakim, who holds the post of state Urban Development and Municipal Affairs minister, has been chosen as the Mayor designate by the councillors of Trinamool Congress, following former Mayor Sovan Chatterjee’s resignation from the post. Also Read – Rain batters Kolkata, cripples normal lifeCPI(M) councillor Bilquis Begum had moved the High Court, challenging Hakim’s election on the ground that he was not an elected councillor from any of the wards of the civic body. Justice Debangshu Basak on Friday directed the state and KMC to file affidavits in opposition to the petition of the CPI(M) councillor and said that the matter will be further heard on December 17. The petitioner has challenged the Kolkata Municipal Corporation (Second Amendment) Bill, 2018, which was passed by the state Assembly recently. It has also received the assent of the Governor, which allows a person who is not an elected councillor, to be made a Mayor of KMC. The person, however, would have to be elected within six months, in order to continue in the post. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed”Some of the councillors could not turn up today (Friday) because of ill health and two of them are presently abroad. But all of them are expected to attend the elections on Monday, which will be held from 1 to 2.30 pm,” said Roy. When asked whether Sovan Chatterjee, who is a councillor of ward 131, will turn up for voting, Roy said: “The message regarding the elections has been passed to all the councillors.” There will be four booths where councillors will be voting. The oath-taking ceremony of the Mayor is also expected to take place on Monday after the announcement of the results. Mina Debi Purohit from BJP will contest against Hakim for the Mayoral post, while Left Front and Congress have announced that they will boycott the voting.last_img read more

first_imgIs your teenage daughter popping pills to shed weight? Beware, she may be at an increased risk of harming hormones, growth as well as mental health, researchers warned.The findings showed that diet pills are unsafe for all ages but especially for teenagers due to the presence of toxic chemicals in the supplements.These pills interfere with the body systems and result in nutritional deficiencies, particularly of iron and calcium, the researchers said. Also Read – Add new books to your shelf”In growing children and teenagers, even a marginal reduction in energy intake can be associated with growth deceleration,” dailymail.co.uk quoted the Canadian Pediatric Society researchers as saying. Weight loss pills are advertised as the quick solution to shedding pounds and obtaining the perfect figure, but they come with potentially dangerous side effects, including increased heart rate, fainting, unusual bleeding and heart attacks.Diet pills can also cause and, in extreme cases they can rip apart the stomach lining and even lead to death, the study showed. Further, researchers from the University of Minnesota said a startling 63 per cent of teenage girls use “unhealthy weight control behaviours” to maintain a slim shape.About 22 per cent of teenage females use “very unhealthy weight control behaviours”. The use of diet pills in teenage girls had a significant spike in a five-year span, jumping from 7.5 per cent to 14.2 per cent in 2006, they claimed.Instead of turning to diet pills, exercise, changing eating habits and drinking more water, mediation, are other healthy ways to lose weight, the reseachers said.last_img read more

first_imgAs you start ageing, skin may begin to sag as a consequence of a natural loss and weakening of collagen and elastin. However keeping in mind a few basic steps can help you in getting rid of the sagging skin. Experts list some steps: -Smart SPF: UV damage speeds up the loss of firmness of the skin, therefore wearing a moisturizer with a broad spectrum sunscreen on a daily basis is the easiest way to help prevent sagging. -Moisturize smartly: It is highly recommended to apply a moisturizer with vitamins C and E both morning and night to your face and neck. Moisturizing is important to keep the skin firm and smooth as you age. While selecting the right moisturizer, look for ingredients like Alose Vera, soy protein, among others. -Need extra effort: To improve the appearance of the skin that is already slightly saggy, you should look for moisturizer with the right, powerful ingredients. Go for a moisturizer that contains peptides and Niacinimide (or vitamin B3).last_img read more

first_imgMost people never get to see the Northern or Southern lights phenomenon up close, let alone a front row view from a seat in an airplane. A New Zealand company chartered a ‘Flight to the Lights’ for 134 people to witness the show first hand on an 8-hour chartered flight.The video from the trip looks like CGI.last_img

first_imgGuests:Doug Gottlieb, Cuttino Mobley, and Dahntay Jones Also:– Dak looks bad talking about Brady’s money– Where Colin was right/wrong– Predicting Kyler Murray’s landing spot– Even the Celtics’ ‘Process’ is flawed America has a big enough football appetite for AAF to surviveThe talk of the weekend was the debut of the Alliance of American Football, and it’s calculation that it can survive by filling the void in America’s football soul during the dead time after the Super Bowl.Colin isn’t crazy about the league’s name – AAF kind of works though- but does think that it can at least be viable because there is real money behind it and America will consume less than NFL quality football to get their fix. No one is saying that the AAF will immediately become a billion dollar juggernaut, but there’s enough demand in the market to support it if it’s done well.last_img read more

first_img Free Webinar | Sept 5: Tips and Tools for Making Progress Toward Important Goals Attend this free webinar and learn how you can maximize efficiency while getting the most critical things done right. Brought to you by PCWorld Register Now » 3 min read December 5, 2007 A few years back, when I replaced my aging Athlon XP-based home-built PC with a faster, quieter system, I stored the old one away presuming that someday I’d do something interesting with it. Microsoft’s Windows Home Server proved the perfect excuse to do just that. The end result is a highly useful, though sometimes frustratingly simplistic, addition to my home tech lineup.Windows Home Server is Microsoft’s first stab at a consumer server product that sits at the heart of your network where other PCs can access its content. Available now on hardware such as HP’s MediaSmart Home Server or as a $180 software package from system-builder sites such as Newegg, Windows Home Server lets you store and stream media files, back up multiple PCs, and connect remotely via the Web. Plus, Microsoft says that add-on features such as video recording and home automation are on the way from third-party vendors.Windows Home Server requires an ethernet connection between the server and the network (Microsoft deemed wireless networking too flaky). I installed a prerelease copy of the operating system in about 2 hours; the only snag I hit involved enabling the remote Web access features. My router turned out to be the problem, and one I wasn’t able to resolve with tech support. To connect client PCs to the server, you install a simple console application on each that also lets you tweak the server’s settings.Soon, I was streaming music, photos, and standard-definition video to my 802.11g-enabled notebook, flawlessly. I experienced some stutters with a high-def test video file, but that’s an 802.11g bandwidth issue. Everything streamed cleanly to my ethernet-connected Windows XP Pro PC and my Xbox 360. The 360 connection is great, as it allows me to access media where I most enjoy it: on my couch, in front of my HDTV.Windows Home Server also lets you back up the entire contents of each connected PC to the server’s hard drive, as a compressed file that it updates daily with only the changes that have occurred since the last backup. The backup feature is quite slick, and it illustrates the degree to which Microsoft has successfully simplified an often-complicated process. You can add more hard drives to the server, and even enable data duplication (essentially RAID 1 data mirroring). But the nitty-gritty settings for such features are largely inaccessible, hidden behind basic wizards and check boxes.Simplicity is great, but I think enthusiasts like me will want access to more knobs and switches. Microsoft might envision a home server in every house, but I’m not sure the average PC user would even know what to do with one (yet). After having lived with the server for a few weeks, though, I can’t imagine not having one–a clear sign that it’s filling a need in my geek household. Better yet, it let me pull my old workhorse PC out of retirement.last_img read more