(PhysOrg.com) — CityWall is a large interactive touch display in central Helsinki Finland. The interactive 3D touch screen display portrays the ever changing landscape of Helsinki as nature and urban life interrelate. The touch screen and applications for the was created by Ubiquitous Interaction and MultiTouch under the auspices of the Helsinki Institute of Information Technology. The exhibit is co-funded by the 6th Framework Research Programme of the European Union. through the IPCity Project. The purpose of the interactive display is to promote a discussion on the benefits, burdens and adjustments city dwellers see in their daily lives relating to the natural world. CityWall–Helsinki Citation: Helsinki Urban/Nature Interactive Invites World-Wide Visitors Via Flickr (2008, October 14) retrieved 18 August 2019 from https://phys.org/news/2008-10-helsinki-urbannature-interactive-world-wide-visitors.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. Helsinki like many urban settings has an urban-wildlife dilemma. In recent years wild rabbits have moved to the city looking for vegetation and a warm place to hunker down and propagate. Helsinki´s city centers, gardens, parks and neighborhoods have been overtaken by rabbits. For some Helsinki residents the rabbits lumbering around monuments, hillsides and scrambling through the city presents a picturesque view. For other residents, the rabbits are a tremendous nuisance. City workers, avid gardeners, health and safety residents don´t find the rabbits one bit cute. Toppled over trash cans, rabbit pellets and destroyed gardens is not a pretty sight in their opinion. The city officials have decided to cull the rabbit population as a solution to the urban-wildlife dilemma. The CityWall interactive touch display allows visitors to upload pictures and comments to the Flickr page. The pictures and comments are then automatically included in the CityWall interactive exhibition in Helsinki. The pictures and comments are divided into two-categories. If you think the nature is a “nice thing” submit your comments and pictures to cwnicehki. If you wish to comment that nature can be a nuisance, submit your comments and pictures to cwnuishski. Everyone is welcome to submit comments and pictures. Anyone wishing to do so will need to use their own Flickr account or establish one at no charge. Contributors are urged to include tags like Helsinki, CityWall and cwhkirabbits if your comment is about the urban rabbits. Thus far the comments both for and against man´s interaction with nature in Helsinki are about even. Some contributors offer photos of Snow Geese causing traffic problems, overgrown bushes blocking bike paths and rabbits ravishing the Helsinki Botanical Gardens. Other contributors point out the difference between the Helsinki Hare and Rabbit. The Hare has longer, black-tipped ears and appears to have longer and more muscular legs. Another distinction is made between the Arctic Hare a family member of the Irish or Celtic Hare and the Brown Hare. Pictures of Hares engaging in pre-connubial boxing matches, resting by the seaside and parks provides a distinctly different view of man´s interaction with nature in an urban setting. Other contributors see both the positive and negative aspects of trees, plants and wild life and appear to be seeking answers for co-habitation with nature. Whether global warming is the cause of wildlife´s exodus into Helsinki or a combination of factors is up for discussion. The 3D interactive touchscreen with a world view stands for the proposition that all views are equally important in understanding the whole.
Black-tailed prairie dogs (Cynomys ludovicianus) are known for their extremely social behavior, which includes kissing, grooming and touching each other. They are also known for their complex language of around 100 different barks, chirping sounds and yelps that convey information about predators, including the type of predator, their size, direction of travel, speed, and even their color. Previous research has shown they can also describe different human beings.Groups of prairie dogs live in large, complex, and interconnected underground tunnels. They post look-outs on mounds near the tunnel system to warn of predators such as foxes, bears, snakes, predatory birds, and humans.The researchers, led by Dr Adam Eltorai of Washington University in St Louis, Missouri, recorded the behavior of a group of 25 black-tailed prairie dogs at the St Louis zoo, and at the same time counted the number of zoo visitors observing them. Dr Eltorai said their study showed that like humans, the prairie dogs often behaved differently when they were being watched, and many seemed to enjoy the attention, becoming more relaxed and spending less time watching for potential dangers as the numbers of visitors increased. As crowd numbers increased, the adult prairie dogs spent less time fighting and showed more affection toward one another, kissing and cuddling up together. The juveniles behaved differently, seeming more tense as the number of visitors to their enclosure increased. The young prairie dogs kissed and cuddled less and fought more as visitor numbers increased. 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) — Researchers in the US studying the behavior of black-tailed prairie dogs at a local zoo have discovered they behave differently, kissing and cuddling each other more when people are watching than when they are unobserved. Dr Eltorai said the behavior of the adults was surprising because humans are one of their predators, and the team expected them to be less relaxed when people were watching. He said the behavior of the young prairie dogs was possibly normal behavior for them, but becomes amplified under the stress of large numbers of observers.Black-tailed prairie dogs are native to North America, being found in much of the western parts of the US and in southern Saskatchewan in Canada.The researchers say their study may help other scientists unravel normal behavior from behavior while under observation, and may help in the design of zoo enclosures that benefit the animals.
Image: Nature, doi:10.1038/nature10748 One of the most commonly known principals in physics is that nothing can travel faster than the speed of light, but that number of course implies a vacuum, because light speed is slowed when passing through other materials. Because such a constant has been so helpful in so many studies, scientists would like to find a similar constant for the speed with which propagation moves through materials.The principle of propagation can be seen by watching a game of pool. When a player pokes a cue ball with a stick, it rolls towards its target. At the start of the game, that target is a triangle of other balls all pressed firmly together. When the cue ball hits its target, the energy from it is transferred through the balls it strikes to those behind it, all in various directions based on the velocity and angle of the cue ball and the precise setup of all the other balls. The end result is propagation of energy with balls flying every which way.Scientists would like to know if there is an actual speed limit in interactions that go on in materials that define propagation speed, because thus far, all they have to rely on is the theoretical speed limit described by the Lieb-Robinson bound.To see if they could find out, the researchers set up an experiment that had far fewer variables. They chose a one-dimensional quantum gas made up of atoms set up in an optical lattice. To form the optical lattice, they used two counter-propagating laser beams to cause the atoms to cool and congregate in troughs, or potential minima. Then, by adjusting the lasers very quickly, they were able to create what is known as a quenched system, whereby excitations occur. In this case, those excitations are known as quasiparticles, which can travel through the lattice. Then, by measuring the distance a quasiparticle traveled in a certain amount of time, they were able to arrive at the speed with which they propagated through the lattice. This is the first time that the Lieb-Robinson bound has been quantified in an experiment. The result isn’t a universal constant, like the speed of light, but it is a number that demonstrates a constant propagation speed though one material, which is groundbreaking news because it’s likely to lead to other studies that measure propagation speeds through other materials, which could have a profound impact on engineering efficient quantum channels which may help efforts to create quantum computers. More information: Light-cone-like spreading of correlations in a quantum many-body system, Nature 481, 484–487 (26 January 2012) doi:10.1038/nature10748AbstractIn relativistic quantum field theory, information propagation is bounded by the speed of light. No such limit exists in the non-relativistic case, although in real physical systems, short-range interactions may be expected to restrict the propagation of information to finite velocities. The question of how fast correlations can spread in quantum many-body systems has been long studied. The existence of a maximal velocity, known as the Lieb–Robinson bound, has been shown theoretically to exist in several interacting many-body systems (for example, spins on a lattice)—such systems can be regarded as exhibiting an effective light cone that bounds the propagation speed of correlations. The existence of such a ‘speed of light’ has profound implications for condensed matter physics and quantum information, but has not been observed experimentally. Here we report the time-resolved detection of propagating correlations in an interacting quantum many-body system. By quenching a one-dimensional quantum gas in an optical lattice, we reveal how quasiparticle pairs transport correlations with a finite velocity across the system, resulting in an effective light cone for the quantum dynamics. Our results open perspectives for understanding the relaxation of closed quantum systems far from equilibrium, and for engineering the efficient quantum channels necessary for fast quantum computations. Explore further Speed limit on the quantum highway 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: Researchers observe speed of propagation in non-relativistic lattice (2012, January 26) retrieved 18 August 2019 from https://phys.org/news/2012-01-propagation-non-relativistic-lattice.html © 2011 PhysOrg.com (PhysOrg.com) — A team of researchers have devised a means for observing the speed with which quasiparticles can travel through an optical lattice. The experiment performed at the Max-Planck-Institut für Quantenoptik, as described in the paper the team has published in Nature, was a demonstration of a method that can be used to measure propagation through a non-relativistic lattice, a first of its kind. Journal information: Nature
Schematic diagram of phonon lasing in a compound resonator system: two microtoroid resonators µR1 (green) and µR2 (blue), are coupled to each other by evanescent fields. The first resonator supports a high-Q optical mode a1, and a mechanical mode with resonance frequency Ωm. The second resonator µR2, supports a low Q optical mode a2, and its damping rate is tuned by a chromium-coated silica nanotip approaching µR2. Credit: Nature Photonics, nature.com/articles/s41566-018-0213-5 Citation: A phonon laser operating at an exceptional point (2018, July 20) retrieved 18 August 2019 from https://phys.org/news/2018-07-phonon-laser-exceptional.html Journal information: Nature Photonics , Nature Physics More information: Jing Zhang et al. A phonon laser operating at an exceptional point, Nature Photonics (2018). DOI: 10.1038/s41566-018-0213-5 Ramy El-Ganainy et al. Non-Hermitian physics and PT symmetry, Nature Physics (2018). DOI: 10.1038/nphys4323 Jacob Khurgin. Phonon lasers gain a sound foundation, Physics (2010). DOI: 10.1103/Physics.3.16 Bo Zhen et al. Spawning rings of exceptional points out of Dirac cones, Nature (2015). DOI: 10.1038/nature14889 Alois Regensburger et al. Parity–time synthetic photonic lattices, Nature (2012). DOI: 10.1038/nature11298 Aram Mooradian. Laser Linewidth, Physics Today (2008). DOI: 10.1063/1.880973 Turning loss into gain. Nature Photonics doi.org/10.1038/s41566-017-0067-2 Interview by David F. P. Pile. Gaining with loss, Nature Photonics (2017). DOI: 10.1038/s41566-017-0060-9 H. Hodaei et al. Dark-state lasers: mode management using exceptional points, Optics Letters (2016). DOI: 10.1364/OL.41.003049 To observe linewidth broadening, the physicists optically excited the mechanical mode of the experimental device with light from a tunable laser coupled to a single microresonator (green) by means of a tapered fiber. Then, to steer the system toward or away from its EP, they introduced additional loss to the second microresonator (blue) using a chromium-coated silica nanofibre tip.The interplay between gain and loss was exploited in this way to tune a phonon laser to an EP. Phonon lasing is interpreted as a three-wave parametric process in which two waves are optical and the third wave is acoustic or mechanical. Zhang et al. provided direct experimental evidence to show complete overlap of optical supermodes at EP, and that EP-enhanced optical noise can be transferred directly to mechanical noise, leading to the observed linewidth broadening in phonon lasers. The practical benefits are easy to grasp: Sound waves propagate at a speed that is about five orders of magnitude less than the speed of light, and the wavelength of sound is thus correspondingly shorter than that of light of the same frequency. This feature can enable highly precise, nondestructive measurements and imaging, as well as achieve a high concentration of energy with focused sound waves. The present work opens new perspectives for the relationship between noise and non-Hermitian physics, with potential applications in related fields such as signal processing technologies. The system can be used as an on-chip phononic device analogous to fully integrated photonic devices for information processing. More interestingly, the studied platform can broaden insights in non-Hermitian physics by enabling the detection and control of EPs in two-level or multi-level systems. Explore further Experimental studies of the EP mostly concern such parity-time symmetric systems that cleverly exploit the interplay between gain and loss to enable entirely new and unexpected features. In one such conceptual leap, unusual optical effects produced in these systems rendered the medium invisible in one direction, a step toward next-generation optical materials with unique properties not seen with natural materials. Such concepts have initiated intense research efforts to explore non-Hermitian systems both experimentally and theoretically. Before the first laser was experimentally demonstrated, Schawlow and Townes calculated the fundamental quantum limit for its linewidth; EPs are historically associated with extreme broadening of the laser linewidth—beyond the fundamental Schawlow–Townes limit. Although theoretical models have provided a framework to calculate laser linewidth, they fail to resolve the problem directly at the EP. Experimentally, it is not straightforward to steer a laser directly to an EP, since photonic laser modes become unstable close to an EP, causing chaotic lasing that could be erroneously perceived as an extremely broad laser line. What really happens to the linewidth when a laser operates at an EP in practice has therefore remained unclear up until now. Understanding the mechanisms responsible for linewidth broadening will enable laser resources with new capabilities that we did not have access to before. Zhang et al., provide an elegant new strategy to tackle this problem as published in Nature Photonics, by working with a phonon laser rather than its optical (photonic) counterpart, to observe its operation at an exceptional point. © 2018 Phys.org , Physics Today In the study, phonon lasers produce coherent sound oscillations (mechanical vibrations) induced by optical pumping, a concept previously developed by Grudinin, Vahala and co-workers ,with characteristics typical for photon lasers. In the present experiment, the researchers used a similar optomechanical system with two coupled silica whispering-gallery-mode microresonators (green and blue). The compound phonon-laser system was steered toward or away from its EP to observe the behavior of phonon lasing near an EP. , Nature Tuning a phonon laser to an exceptional point: the first column is a schematic of the distribution of the optical supermodes a± in the two resonators. The second column illustrates the frequency difference and linewidths of the two optical supermodes a±. The last column represents the linewidth of the phonon laser. The EP at which the two optical supermodes coalesce is at c, highlighted in red. The system transits from well separated and symmetrically distributed optical supermodes at a,b, to increasingly overlapping supermodes with complete overlap seen at c. Driven by the optical modes the phonon laser inherits the increased optical noise, reflected by a broadened mechanical linewidth (red box). The regime after the EP is seen at d, e, pushing the system away from the EP leading to linewidth narrowing of the phonon laser. Credit: Nature Photonics, nature.com/articles/s41566-018-0213-5 The basic quanta of light (photon) and sound (phonon) are bosonic particles that largely obey similar rules and are in general very good analogs of one another. Physicists have explored this analogy in recent experimental investigations of a phonon laser to provide insights into a long-debated issue of how a laser—or more specifically, its line width—is affected when operated at an exceptional point (EP). Exceptional points are singularities in the energy functions of a physical system at which two light modes coalesce (combine into one mode) to produce unusual effects. Until recently, the concept mainly existed only in theory, but received renewed attention with experimental demonstrations in optical systems such as lasers and photonic structures. The experimental studies involved systems with parity-time symmetry for balanced gain and loss of material, to ensure robust light intensity, immune to backscatter. While closed and lossless physical systems are described by Hermitian operators in quantum physics, systems with open boundaries that exhibit exceptional points (EPs) are non-Hermitian. , Optics Letters Researchers build fully mechanical phonon laser 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.
I always feel embarassed when I am asked to read from a book that is 24 years old,’ exclaimed Upamanyu Chatterjee at a session of the Jaipur Literature Festival, where he was expected to do just that. Chatterjee might feel shy of still receiving accolades for a book that is more than two decades old, but his readers, if the packed Durbar hall of Diggi Palace, the venue for the book reading, is any indication, aren’t tired of hearing him talk about it. The crowds turned up at Diggi Palace to not only hear Chatterjee read passages from his book, but to question him about it and get their personal copies of Also Read – ‘Playing Jojo was emotionally exhausting’English, August signed by the author.If the test of a classic is that it stands the test of time, then Upamanyu Chatterjee’s English, August definitely deserves a place in the archives of modern Indian classics. Chatterjee burst in to the still nascent field of Indian writing in English with his debut novel in 1988, and was hailed as the next big thing. It is roughly 25 years since English, August was published (1998 to 2013). Though he did come up with several books – Also Read – Leslie doing new comedy special with NetflixThe Last Burden, Mammaries of the Welfare State, Weight Loss and Way to Go, none were as famous as English, August. Many had expected Chatterjee to take up writing as a full time occupation, but like his protagonist Agastya Sen, Chatterjee settles down to being a civil servant. And when he does come to lit meets, he hardly gives a straight answer to any of the questions put to him, evading them with witty one-liners. It is as if Chatterjee is mostly having an inner dialogue and he can’t be bothered to share what amuses him. For many it is difficult to peg him right – is he a happy -civil servant-cum-reluctant-author, or reluctant-civil-servant-come-happy-author? And yet his often arrogant and wicked humour does little to diminish his popularity. ‘He reminds me of Sir Humphrey Appleby from Yes Minister,’ said a delighted young member of the audience, after Chatterjee had given a long-winded answer to a question relating to his portrayal of the civil services, which pretty much said nothing.The world and times of Agastya Sen and his creator are very different from the present. Agastya is the product of an urban India that was still very colonial in its ways. The India that it presents is the India that was being shown in the offbeat cinemas that made actors like Rahul Bose famous. Marijuana and masturbation may tie him to the youth of today, but the number of those who have their heads full of Marcus Aurelius, would be significantly lower than in Agastya’s time. While Agastya would raise his eyebrows at his subordinate’s use of ‘hardly must’ in conversation, today’s generation thrives on ‘we are like this, only’ attitude. Information explosion on television and the online media has ensured a fading of the divide between the urban and the rural world. Yet what continues to ensure the appeal of Agastya’s at times confused and at times sharp presentation of the dichotomy between his upbringing and his surroundings, is the mystery that creates a classic.
Amish Tripathi, the author of the Shiva trilogy books, was the cynosure at a launch event on 14 March, amidst a vivacious crowd. The banker turned author released the third book of the series, The Oath of the Vayuputras, along with Ajay Mago and Sanjay mago, the proprietors of Om Book Shop.Amish seemed exuberant to answer the questions from a wide range of audience from school goers, college students, professionals and house wives, after releasing the book. The evening ended with all the fans getting their copies of the book personally signed by Amish and standing together for pictures with their favorite author. Also Read – ‘Playing Jojo was emotionally exhausting’The questions from the audience were varicolored ranging from the audio visual version of The Immortals of Meluha, the first of the trilogy, which had been purchased by the Dharma Productions to the journey of the author.Amish, a fervent devotee of Lord Shiva stressed on the liberal view of religions and expressed his love for Pantheology. One of the audience also presented him a portrait of Ardhanarishvara, a composite androgynous form of Lord Shiva and his consort Parvati.The Shiva Trilogy, comprising of The Immortals of Meluha, The Secret of the Nagas and The Oath of the Vayuputras has been one of the most successful book series in the history of Indian publishing. It has sold almost a million copies in two-and-a-half years.
The evening of 23 September was one to remember for thousands of families of Palwal Region who got a gift of quality healthcare via Premia Group Premia HealthCare acquisition of a leading running hospital on the occasion of Birthday Celebration of CMD – Premia Group and real estate guru Tarun Shienh.Tarun has always been a forerunner when it comes to social causes and lending a hand to those who need it the most. Social responsibilities form an integral part of his thought process and always occupy a position in his mind. This fact is amply visible in his actions and endeavors and the night of his birthday was no different. Having announced the incredibly selfless gesture, when approached in regard to the news, he said, ‘I have always thought about giving back to the society I have flourished in. Also Read – ‘Playing Jojo was emotionally exhausting’I have taken many steps in this direction and this latest initiative is for those who deserve a future worth cherishing. Birthdays are meant to be occasions to remember and this is precisely what I intend to achieve with this announcement. It is an auspicious occasion and I wanted it to be as special for the people of Palwal as it is for me. I am happy to see myself doing something that has brought smiles to the face of others. Premia Hospital Palwal is an initiative that will mark the foray of Premia Group into Healthcare Industry.’
The dance presentation, Shiva Shakti, consisted of a series of magnificent recitals that attempted to portray the union of Shiva, the male principle and pure consciousness with Shakti, the dynamic feminine energy.The narrator of the recital explains, ‘In the ancient Indian philosophy of tantra, it is said that the Kundalini Shakti exists in every atom of the universe. Kundalini Shakti in its dormant state is represented by a coiled snake, nestled at the base of the spine. When this energy is awakened, it ascends through the seven chakras to unite above the crown of the head with Shiva. This consummation creates an experience of bliss. This Kundalini Shakti in each one of us, unites us and connects us in the dance of Shiva.’ Also Read – ‘Playing Jojo was emotionally exhausting’The show was directed by Dev Issaro, choreographed by Daksha Sheth and her daughter Isha Sharvani and the music was orchestrated by Tao Issaro. Throughout her career, Daksha Seth has explored various art movements from different corners of India: Kathak from the North, Mayurbhanj Chhau from the East, the martial art of Lakaripayattu from the South and aerial techniques of Mallakhamb from the West. She and Dev Issaro amalgamated all these disciplines with dramatic staging and innovative music to formulate a strong and vibrant dance-drama experience with indigenous roots.All the performers in the show were from the Daksha Sheth Dance Company that boasts of its unique form of dance expression that the audience enjoyed in all its vibrancy.Some of the dignitaries present at the occasion were Kiran Bedi, Shubha Mudgal, Abha Dalmia, Herbart Traxl, Shailesh Khaitan, Radha Reddy and Kaushalya Reddy.
The Prime Minister’s Office on Friday suggested that a ‘Dhanteras’ photo used on Prime Minister Narendra Modi’s facebook page was publicly available and there was no need to take permission of the photographer. PMO sources said this in the wake of claims that the photograph was protected by US Copyright law.The photograph has been used on several websites, including that of the Australian government, the sources said. The photo was sent by a creative agency which has clarified that it was available on prominent and legitimate websites which offer the option of downloading it for free, the sources said.