a) Spontaneous parametric down conversion: A photon from a laser beam excites a nonlinear medium (usually a crystal) to a virtual level that decays spontaneously into two possible paths. Either an identical laser photon is created or a pair of photons appear. Their energy adds up to the energy of the laser photon. Photons from all colors (wavelengths) can be obtained. b) The photon pairs follow directions given by linear momentum conservation. F designate an optical interference filter. Image: Geraldo A. Barbosa, arXiv:1202.5434v1 [q-bio.NC] © 2011 PhysOrg.com Mercedes demos DICE — Interactive dashboard and Heads-Up display (PhysOrg.com) — Geraldo Barbosa, professor of electrical engineering and computer science at Northwestern University has posed an interesting challenge. He wonders if the human eye and brain together are capable of actually seeing entangled images. This is not a philosophical question, as he has phrased the query as part of a practical experiment that someone with the proper lab could actually carry out. To that end, he’s posted a paper on the preprint server arXiv with the hope that a physics team will take up the challenge. Explore further The whole idea is based on entanglement and the means by which researchers make it come about. What they do is shoot a laser at a non-linear crystal causing the photons in the beam to be converted into lower frequency entangled pairs. Those pairs are then directed to sensors which individually are able to measure a fuzzy or blurred “image”. But when both of the entangled photons are taken together as a single measurement, the image sharpens. These images are of course far too small for the human eye to see, plus they don’t last long enough for them to be seen anyway. To address these issues, researchers have taken to firing lasers that are formed into patterns such as a doughnut shape in a continuous sequence. The result is a steady stream of entangled pairs being created in the shape of a doughnut.Barbosa wants to know what would happen if instead of forming a doughnut shape, the lasers were made to look like a letter in the alphabet, such as the letter A, and then of course if it were made large enough to be seen by the human eye. Two entangled letter As should be created and seeable albeit in a lower frequency. If that happened, would the human eye when paired with the brain’s abilities, be able to merge the two into a sharp readable image, or would we see just the individual blurred images captured by just one sensor?Barbosa doesn’t know, and neither does anyone else, thus he suggests someone or some group build an experiment to find out.The ability to see things differently than we are accustomed to seeing isn’t anything new of course. Some animals can see things in the infrared spectrum for example and evidence has been slowly emerging as described here, here and here, suggesting that some migrating birds are able to “see” the Earth’s magnetic field. So maybe it’s possible that we see entangled images every day, and just don’t know it.Hopefully someone will take Barbosa up on his challenge, and then we’ll all find out if it’s possible or not. More information: Can humans see beyond intensity images? by Geraldo A. Barbosa, arXiv:1202.5434v1 [q-bio.NC] arxiv.org/abs/1202.5434AbstractThe human’s visual system detect intensity images. Quite interesting, detector systems have shown the existence of different kind of images. Among them, images obtained by two detectors (detector array or spatially scanning detector) capturing signals within short window times may reveal a “hidden” image not contained in either isolated detector: Information on this image depend on the two detectors simultaneously. In general, they are called “high-order” images because they may depend on more than two electric fields. Intensity images depend on the square of magnitude of the light’s electric field. Can the human visual sensory system perceive high-order images as well? This paper proposes a way to test this idea. A positive answer could give new insights on the “visual-conscience” machinery, opening a new sensory channel for humans. Applications could be devised, e.g., head position sensing, privacy in communications at visual ranges and many others.via ArXiv blog Citation: Professor proposes challenge to prove whether people can see entangled images (2012, February 29) retrieved 18 August 2019 from https://phys.org/news/2012-02-professor-people-entangled-images.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.
Physics duo create tractor beam using dual Bessel beams More information: Acoustic Tractor Beam, Phys. Rev. Lett. 112, 174302 – Published 30 April 2014. dx.doi.org/10.1103/PhysRevLett.112.174302ABSTRACTNegative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system. (a) Nonconservative pushing force exerted on an object by a plane wave as a result of strong backscattering. (b) Decreasing of the pushing force due to an enhanced forward scattering in a nonparaxial beam. (c) The authors used a target designed to maximize the forward scattering of acoustic radiation, leading to a pulling nonconservative force towards the source: an acoustic tractor beam. Credit: APS/Alan Stonebraker (Phys.org) —A team of researchers with members from the U.K., Scotland and the U.S. has built a functioning acoustic tractor beam in a lab—one that is able to pull objects of centimeter size. In their paper published in the journal Physical Review Letters, the team describes how they built their device, why it works and to what applications it might be put. Journal information: Physical Review Letters Because of the stipulations required to make it work, applications that could make use of such a tractor beam are clearly limited, though the researchers suggest it might prove useful in some medical situations. Experimental configuration to demonstrate negative radiation forces with a planar ultrasonic array. (a) Scaled cross-sectional geometry of the 550 kHz planar matrix array source and hollow, prism-shaped targets suspended above the array. Linear phase gradients applied to the array elements produce wave fronts steered at θ=50.6° towards the array center line. Active subapertures, forming a hollow core with diameter Δxn, are stepped towards the center line by the array element pitch, with a corresponding lateral (±x) shift in the transmitted local wave fronts and an axial (−z) shift of the intersection with the axis. (b),(c) Normalized maps of simulated instantaneous pressure field and (d),(e) measured magnitude of the pressure field produced by the transmitting subapertures illustrated under the field maps. Credit: (c) PRL, DOI: 10.1103/PhysRevLett.112.174302 Tractor beams, as we all know are a staple of science fiction—a beam is emitted from a spaceship that can be used to lock on to other objects, such as another space ship, and then used to move that other object in any direction, most interestingly, in the same direction from which the beam is being emitted—pulling it in. Tractor beams seem counterintuitive as beams of light tend to push objects away, rather than attract them—but, as prior research has shown, optical tractor beams can be created at the nanoparticle level, e.g. optical tweezers. In this new effort, the research team has extended the abilities of a tractor beam by using one based on acoustics, rather than optics.Sending a beam (wave) at an object and having it pull the object closer rather than push it can work because of the scattering of the wave that occurs when it collides with the object and if the wave is sent at an angle to the object. If the scattering and angle are controlled just right, a low pressure zone can be created in front of the object, in effect, pushing it back towards the origin of the beam. In the lab, the researchers used ultrasonic sound waves in a tank of water. They put an array of ultrasound emitters at the bottom of the tank and used a hollow isosceles triangular prism as the object to be pulled. Using an array of emitters allowed for very precisely controlling the wave, which allowed for directing energy onto the outer surface of the object, causing backscattering that led to the frontal low pressure zone, which in turn led to pushing the object back towards the wave source. An analogy would be squeezing a chocolate chip with your fingers, forcing it to move in whatever direction you choose. Citation: Researchers build acoustic tractor beam (2014, May 8) retrieved 18 August 2019 from https://phys.org/news/2014-05-acoustic-tractor.html Explore further © 2014 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. The content is provided for information purposes only.
Scientists have speculated about the ability to evolve designless nanoscale networks of inanimate matter with the same robust capacities as natural computers, but have not yet realized the concept. Now, a group of researchers reports in Nature Nanotechnology a disordered nanomaterials system that was artificially evolved by optimizing the values of control voltages according to a genetic algorithm. Using interconnected metal nanoparticles, which act as nonlinear single-electron transistors, the researchers were able to exploit the system’s emergent network properties to create a universal, reconfigurable Boolean gate. The authors note that their system meets the requirements for a cellular neural network—universality, compactness, robustness and evolvability. Their approach works around the device-to-device variations that are becoming increasingly difficult to align as semiconductors approach the nanoscale, and which result in uncertainties in performance.Their system is a disordered nanoparticle network that can be reconfigured in situ into any two-input Boolean logic gate by tuning six static control voltages. It exploits the rich emergent behavior of up to 100 arbitrarily interconnected nanoparticles. For the experiment, the researchers used 20 nm gold nanoparticles interconnected with insulating molecules. These single-electron transistors express strongly nonlinear switching behavior, and the researchers looked for logic gates among the mutual interactions between them.The fastest method proved to be artificial evolution. They developed a genetic algorithm that followed the well-known rules of natural selection, considering each control voltage as a gene and the complete set of system voltages as a genome. The best-performing (i.e., “fittest”) genomes were preserved and improved via a composite cloning-breeding approach. The desirable traits of the initial, mostly low-performing genomes were passed selectively to subsequent generations. For each logic gate evolved, the genetic algorithm almost always converged to a viable genome within less than 200 generations. The researchers note that due to the slow input signals they used, the process took about an hour; optimizing the system set-up could result in faster evolution. “Using the artificial evolution procedure… we succeeded to realize fully configurable, robust Boolean logic in disordered nanoparticle networks at our base temperature of ~0.3 K. These results comprise the first experimental demonstration of exploiting disordered matter at the nanoscale for computational functionality,” the authors write.They note that the system meets the criteria for the physical realization of cellular neural network and that the same evolutionary approach with a more sophisticated electrode layout could yield many more computational tasks. “Our evolutionary approach works around device-to-device variations at the nanoscale and the accompanying uncertainties in performance, which is increasingly becoming a bottleneck for the miniaturization of conventional electronic circuits. The results, therefore, also need to be seen in the light of these exciting possibilities,” they write. © 2015 Phys.org Citation: Researchers use disordered matter for computation, evolving breakthrough nanoparticle Boolean logic network (2015, September 25) retrieved 18 August 2019 from https://phys.org/news/2015-09-disordered-evolving-breakthrough-nanoparticle-boolean.html Working electronic circuits produced through artificial evolution 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. More information: “Evolution of a designless nanoparticle network into reconfigurable Boolean logic.” Nature Nanotechnology (2015) DOI: 10.1038/nnano.2015.207AbstractNatural computers exploit the emergent properties and massive parallelism of interconnected networks of locally active components. Evolution has resulted in systems that compute quickly and that use energy efficiently, utilizing whatever physical properties are exploitable. Man-made computers, on the other hand, are based on circuits of functional units that follow given design rules. Hence, potentially exploitable physical processes, such as capacitive crosstalk, to solve a problem are left out. Until now, designless nanoscale networks of inanimate matter that exhibit robust computational functionality had not been realized. Here we artificially evolve the electrical properties of a disordered nanomaterials system (by optimizing the values of control voltages using a genetic algorithm) to perform computational tasks reconfigurably. We exploit the rich behaviour that emerges from interconnected metal nanoparticles, which act as strongly nonlinear single-electron transistors, and find that this nanoscale architecture can be configured in situ into any Boolean logic gate. This universal, reconfigurable gate would require about ten transistors in a conventional circuit. Our system meets the criteria for the physical realization of (cellular) neural networks: universality (arbitrary Boolean functions), compactness, robustness and evolvability, which implies scalability to perform more advanced tasks. Our evolutionary approach works around device-to-device variations and the accompanying uncertainties in performance. Moreover, it bears a great potential for more energy-efficient computation, and for solving problems that are very hard to tackle in conventional architectures.
What do you think of the current music scene in India. There’s a whole new buzz about our music. What is your opinion.To be honest we have no idea what is going on now in India music wise. It’s one of our major goals when we are there. Finding out what is hot and what is not. We love traditional and classic Indian music, and also love the Indian pop culture. But it has been a while since we were there…The young generation is trying to experiment. Is that a good thing always? Also Read – ‘Playing Jojo was emotionally exhausting’Music is like fashion and design, a sign of the times, giving each time its own look or sound score. Always on the move, always taking steps forwards, sometimes looking back at older styles and reinventing them. There have been great new artistes lately, pushing the boundaries of music a little forward. Unfortunately. there has not been a style which has been revolutionary in the past eight years or so, like Charleston, jazz, rock and roll, hippie, disco, punk, new wave, house music, techno and electro have been in their era. It seems there are too few angry young people and lots of music is made to make as much money as possible, not to create or stir a revolution. But for sure this will change, it’s the nature of human beings, to change, sometimes slowly, sometimes fast. We can’t wait to hear what the future sounds like. Also Read – Leslie doing new comedy special with NetflixWhat do you think sets you guys apart?There are not that many DJs who do music for the fashion industry. You have to love both music and fashion and know how both worlds work. The music industry is mostly afraid of fashion, mainly because they do not understand what it is all about, the fashion industry loves music though… We love both worlds and we love putting on a show. We are perfectionists and always looking for ways to do things different so the music you’ll hear at a show stands out and makes the clothes look good! You have been associated with a lot of different kinds of music. What keeps you going?There’s so much music, from ethnic to classical, from pop to experimental and underground. It’s like finding treasures all the time, and finding out how things can work with collections is like an experimental puzzle. You never know what a designer comes up with, there’s always the challenge to make it work out. We love it.Some inspirations and experiences which have enriched you.To be honest, it’s always the next show which is the most inspiring, the kick of finding out what to do and making it work. And, as we said, there’s so much music in the world, there’s always an artiste who we do not know, or a certain style which opens a complete new world for us. Lately, we have been inspired by new young artistes like Trippple Nippples from Japan and Grimes from the USA, but are also digging deep into the music made by French singer and composer Serge Gainsbourg and are discovering the works of minimal classical composer Otte.If you were making a debut, hypothetically, at this point of life what do you think as a newcomer you are likely to offer your audience?Guts and the power to create something fresh! If you had to do something all over again what would that be?If we listen to some of our really old mixes we would do them completely differently. In the beginning we were thinking of electronic dance music, while nowadays we are open to any style of music.Does India listen to anything other than Bollywood? Of course it does. The music from India has a great history, there’s beautiful classical and traditional music and there has to be new stuff and artistes which we do not know [yet]. We can’t wait for the workshop where we are hopefully going to find out much and much more.
The evening brought together acclaimed Bollywood poets at ICCR’s (Indian Council for Cultural Relations) poetical soiree: From Rahat Indori of Munnabhai MBBS fame to Padma Shri Nida Fazli who has Star screen award for Sur in his kitty besides his popular film songs in Razia Sultan and Sarfarosh. MP Karan Singh lit up the lamps as the chief guest for the occasion. He began the evening with a tribute to the power of goddess and woman to mark the onset of Navratras.The auditorium reverberated with fervent applause and praise unequivocally, by an audience enraptured with the line up of poets and poetesses. It concluded with a promise of continuing the tradition of holding Kavi Sammelan atleast once a year by ICCR.
The show titled Bhumi brings together yoga, spirituality and organic relationship with the Earth to spread uplifting, hopeful messages to inspire the audience.Bhumi is the brainchild of Goura Prema, India’s Got Talent Finalist and Director of Natya Nectar. Presented by the Natya Nectar International Dance Company, Bhumi is rooted in the earth, but supported by four pillars that will provide a strong base to hold up this monumental performance.What Bhumi stands for the aesthetic rendering of the relationship between Mother Earth and her inhabitants. It will explore environmental issues, in India, that lead to diseases, and health concerns, which impact our future. But more importantly, it will highlight the solutions. The four supporting mediums will interlace a narrative of holistic life. Also Read – ‘Playing Jojo was emotionally exhausting’Prema started her dance academy Natya Nectar Dance Company in 2008 in New Delhi. Her vision is to make a deep impact on audiences around the world, with the great stories of Mahabharat, Ramayana and Bhagavad-gita. Her passion for art forms has been extended to aerial silks and acro yoga as well with equal amount of poise. She has been practicing Aerial Silks for over 6 years and has received extensive training in San Francisco and LA.When: 5 November, 7:30 onwardsWhere: Kamani Auditorium
India has the largest population of vulnerable and street children in the world. 11 million of these kids are living or working on the brutal streets, out of education, and are not recognized officially in any way. To help this less fortunate kids find their way, PayUMoney and MasterCard present a rare opportunity Colour My Life to the previleged children. This initiative allows fortunate and school going children to help the less fortunate and underprivileged ones. Also Read – ‘Playing Jojo was emotionally exhausting’Through the campaign, we have the chance to instill great values in the children by encouraging them to visualize, empathize and portray the rough life of street children. Thus invoking a sense of compassion and responsibility of the privileged towards the underprivileged. We have an opportunity to raise awareness amongst the privileged class that, an extremely vulnerable group of children need our attention and help in providing them with a safe educated, healthy and sound environment. Also Read – Leslie doing new comedy special with NetflixEvery street child should not only be made aware of their right to education but also have the facility to exercise this right.The chidren have a chance to contribute towards this cause through their simple artwork. Each participating student will be required to pay a small amount of Rs.10. This sum will be shared with India Vision Foundation, an NGO that works towards improving the lives of street children.4500 students from 150 schools registered in the campaign where 1200+ art work were uploaded. Out of the total 1200+ entries so far, top 50 will be selected through an online voting mechanism and Jury’s discretion. The top 50 entries will be exhibited today . Out of these 50 arts, top 6 winners will be selected and felicitated by Kiran Bedi. The final top 6 entries will win cash prize worth Rs 11,000 each. The top 50 entries will be sold through an online and offline auction and the money raised through it will be handed over to India Vision Foundation.When: 26 April Where: Epicentre, GurgaonTiming: 2.30-7 pm
The walk will trace the origin of Sufism, it’s advent in India, the several orders of Sufism and the characteristic differences as well as the Pir and Murid (master and disciple) relationship. The walk will be covering the following monuments and ruins in the same sequence – Hauze-e-Samsi (water tank), Jahaz Mahal (water boat palace from 15th century), Jharna (water fall from 18th century), Khawaja Syed Ghaznavi’s darga (a sufi saint from the Qadri order), Kala Mahal (an old khanaqha which is now a Madarassa), Zafar Mahal (Bahadhur Shah Zafar’s summer palace) and Khawaja Qutubuddin Bakhtiyar. The walk will end with a theatre performance of Bahadur Shah Zafar II inside the Zafar Mahal. The booking will be closed after 20 participants, so sign up quick!When: 14 September Meeting Point: Chattarpur Metro Station Timing: 9.30 am to 12.00 pm Charges: Rs 1000/person, a group book of 3 or more: Rs 900/person