Quantum dots as midinfrared emitters Explore further Now, though, that view has changed. Kambhampati says that he and his colleagues at McGill University in Montreal, Quebec, Canada have figured out how to train lasers to properly drive a quantum dot so that light amplification is in line with theories developed years ago. Ryan Cooney, Samuel Sewall, D.M. Sagar and Kambhampati present the results of their experiment in Physical Review Letters: “Gain Control in Semiconductor Quantum Dots via State-Resolved Optical Pumping.”“We figured that if you took the quantum dot that most had given up on,” continues Kambhampati, “that we could figure out why it wasn’t working as predicted, and try to determine what went wrong. We found out that it was all in the way that experiments were done. By virtue of the available driving lasers, previous experiments were coincidentally done under conditions that were actually best for blocking the useful amplification process. Quantum dots may actually be more useful for light amplification than previously imagined. They have the potential to be very powerful.”Kambhampati and his peers discovered that the clue to getting the quantum dots to properly amplify light was in the color of the laser light used to power the dot. “Each quantum dot is different,” Kambhampati explains. “Everything absorbs different colors of light, and that is true of quantum dots. We found that you have to know which colors works for which dots. Certain colors will produce amplification as theoretically predicted. The color of the laser being used to pump the dot is one of the most important factors.” Once you know that information, it is possible to use the laser to drive the quantum dot appropriately. The Montreal group “trained” their lasers to find the correct color in order to pump the quantum dot in such a manner as to amplify the light. In this manner, they were able to stimulate emission in quantum dots using specific interactions. The way that these quantum dots are pumped, “squeezing” light into the box-like structure, makes a big difference in the output seen.Even though Kambhampati can see uses for such light amplifiers down the road – especially in terms of fiber optics and long-distance telecommunications, he acknowledges that there are some fairly significant hurdles to overcome. The first problem is that right now the lasers used to drive the dots are prohibitively expensive for commercial use. “Telecom companies don’t have the same scientific lasers that we have to produce different colors. The eventual goal is to be able to make small, cheap practical lasers that can be used commercially.” He says that there are already efforts underway to figure out how to fine tune lasers to work in this manner, but “sometimes there is a long path from science to engineering to manufacturing.”Kambhampati remains hopeful, however. And he also points out that there are some other interesting things to learn on a fundamental from this experiment. “We saw some things that no one has seen before – things not seen in a quantum well.” In addition to long-term commercial uses, it is possible that this experiment could help other investigations dealing with extremely short pulses, or that require an efficient white light source.“Really, this is just the beginning. A number of interesting ideas, fundamentally and practically, may come out of this ability to control the output of a quantum dot.”More information: Ryan R. Cooney, Samuel L. Sewall, D.M. Sagar, and Patanjali Kambhampati, “Gain Control in Semiconductor Quantum Dots via State-Resolved Optical Pumping.” Physical Review Letters (2009). Available online: link.aps.org/doi/10.1103/PhysRevLett.102.127404 . Copyright 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. (PhysOrg.com) — “Quantum wells have been instrumental in telecommunications, enabling light amplification,” Patanjali Kambhampati tells PhysOrg.com, “but theory has suggested that a very small – colloidal – quantum dot could amplify light even better than a quantum well. There have been problems, however, in getting lasers to work properly with colloidal quantum dots, so focus has shifted to other types of structures.” Citation: ‘Squeezing’ light into quantum dots (2009, April 1) retrieved 18 August 2019 from https://phys.org/news/2009-04-quantum-dots.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.
(PhysOrg.com) — Semiconductors provide the bases for many different avenues of device research. Indeed, many of the technological devices that are commonplace in our society are reliant on semiconductors. However, as we increasingly explore the opportunities afforded on the nanoscale, new semiconductor materials are needed. One of the more promising semiconducting materials at this level is the carbon nanotube (CNT). More information: Lai, et al., “Engineering the band gap of carbon nanotube for infrared sensors,” Physical Review Letters (2009). Available online: link.aip.org/link/?APPLAB/95/221107/1 Copyright 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. Citation: Using CNTs as infrared sensors (2010, January 4) retrieved 18 August 2019 from https://phys.org/news/2010-01-cnts-infrared-sensors.html Explore further “There is great promise in using a carbon nanotubes for sensors.” Ning Xi tells PhysOrg.com. Xi is John D. Ryder Professor of Electrical and Computer Engineering at Michigan State University, and leads a group that is working on engineering CNT band gaps for use as infrared sensors. Xi worked with Kin Wai Chiu Lai, Carmen Kar Man Fung and Hongzhi Chen at Michigan State, and Tzyh-Jong Tarn at Wasington University in St. Louis to develop a process that is described in Applied Physics Letters: “Engineering the band gap of carbon nanotube for infrared sensors.” This project is supported by the Office of Naval Research.“For semiconductor material, the band gap is one of the most important parameters,” Xi explains. “The band gap represents how much energy is needed to move an electron. In order for the electron to move, it has to be able to jump over this gap. You have to change the composition of the material in order to change the band gap, and this is very difficult. People have been trying all kinds of ways to do this for years.”As far as sensors are concerned, using CNTs with different band gaps can help pinpoint different types of light. “Infrared light has a certain wavelength,” Xi says. “You need a certain band gap to detect this. If you have nanotubes with different band gaps, you can design a sensor to detect different spectrum of infrared. And since these nanotubes are so small, arraying different CNTs with different band gaps is possible.”In order to engineer the band gaps so that they can provide the semiconducting sensors, Xi and his colleagues created a process of stripping away layers of multi-wall CNTs. “The interesting thing with carbon nanotubes is that the band gap depends on the radius. If you have a multi-wall nanotube, you can peel away the outer layer to change the radius. And that changes the band gap as well. Instead of changing the semiconductor material, it is possible to tune the band gap to the proper value, one step at a time.”Xi and his colleagues and collaborator developed a process that allows them to use feedback control to remove layers of multi-wall CNTs. “We were able to do this experimentally, with relative ease compared to earlier processes for band gap tuning,” Xi points out. “We were able to generate different types of carbon nanotubes with different band gaps, and able to detect multiple wavelengths of light across a spectrum.” Being able to tune a band gap without having to make a new material is a big step forward in semiconductors, and Xi hopes that this process can be used for other purposes. “We are primarily interested in infrared nanosensors, but there could be other applications for this technology.” 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. Boron Nitride Nanotubes More Amenable Than Carbon
Explore further (Phys.org) — Back in November, a paper posted to a preprint server arXiv by three British physicists prompted some heated debate regarding the nature of the quantum wave function, a probability function that physicists use to help them better understand the quantum world. At the time, the three refrained from joining in on subsequent discussions on the paper due to pending acceptance of the paper in the journal Nature Physics. Now that the paper has been accepted and printed, the three, Matthew Pusey, Jonathan Barrett and Terry Rudolph are openly defending their assertion that the wave function is real, not some function that is dependent on available information for the user when using it. At the heart of the issue are the contrasting ideas on the very nature of quantum mechanics itself. In their paper, the British physicists contend that the wave function is not just a tool that can be used for statistical purposes, but can measure actual real things. Others have suggested that it cannot be a real tool because of inconsistencies in observable quantum mechanics, such as entanglement. Because of such inconsistencies, physicists such as Einstein contended that our knowledge or model of quantum mechanics is incomplete, not wrong. It’s possible the thinking goes, as an example, that because two distant entangled particles react in identically the same way at the same time, seemingly sharing information faster than the speed of light, that there is some new element of quantum mechanics at work that would allow for such a real world phenomenon to exist, rather than an example of the failure of quantum mechanics theory itself. Another example is the differing views regarding Schrödinger’s cat. Some might say the wave function could be used to prove whether the unseen and thus un-measurable cat is truly dead or alive, whereas others, such as Einstein would say that because the inquisitor has only partial knowledge, no true answer can be given.The problem with proving which view is true is the theory that most agree on and that is that quantum states can be changed simply by measuring them, which means, that as things stand now, physicists have no way of proving what state existed prior to measurement. But that doesn’t mean the wave function can’t be used to measure a quantum state, Pusey et al say, because the true state did exist before measurement occurred. At that moment it was real, they say, as is the wave function and they believe they have proved it. Journal information: Nature Physics Does the quantum wave function represent reality? © 2012 Phys.Org More information: On the reality of the quantum state, Nature Physics (2012) doi:10.1038/nphys2309Quantum states are the key mathematical objects in quantum theory. It is therefore surprising that physicists have been unable to agree on what a quantum state truly represents. One possibility is that a pure quantum state corresponds directly to reality. However, there is a long history of suggestions that a quantum state (even a pure state) represents only knowledge or information about some aspect of reality. Here we show that any model in which a quantum state represents mere information about an underlying physical state of the system, and in which systems that are prepared independently have independent physical states, must make predictions that contradict those of quantum theory.via Nature News Citation: Paper stirs up controversy over the nature of the quantum wave function (2012, May 9) retrieved 18 August 2019 from https://phys.org/news/2012-05-paper-controversy-nature-quantum-function.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. The researchers’ definition of a physical property is illustrated here. Image (c) Nature Physics (2012) doi:10.1038/nphys2309
Too scary to be real, research looks to quantify eeriness in virtual characters Citation: Uncanny Valley robots essay resurfaces 42 years later (2012, June 13) retrieved 18 August 2019 from https://phys.org/news/2012-06-uncanny-valley-robots-essay-resurfaces.html (Phys.org) — An essay on robots by a professor in Japan over 40 years ago has just got its official translation. Many in robotics and other science circles will say better late than never for an official translation of Yasahiro Mori’s paper, “The Uncanny Valley” which was published in a Japanese journal called Energy 42 years earlier. The essay has generated interest about the extent and limitations of making robots more and more human-like in human-robot interaction. An English translation was done in 2005 but the translation that has been authorized and and reviewed by Mori was published Tuesday in IEEE Spectrum. “I have noticed that, in climbing toward the goal of making robots appear human, our affinity for them increases until we come to a valley (Figure 1), which I call the uncanny valley.” That observation from his original essay is what sparked conversations and interest among robotic designers over the years. Mori maintains that humans are drawn to human-like robots with positive feelings of affinity until the robot moves or reveals itself in such a way that triggers the person’s realization that it is not human. Then it becomes “uncanny” or in popular-culture terms, creepy. Affinity is lost. In his essay, Mori expressed this experience in a graph, and he also offered an example, the prosthetic hand. The human being gets an “eerie sensation,” he said, when realizing that the hand is not real. “We could be startled during a handshake by its limp boneless grip together with its texture and coldness. When this happens, we lose our sense of affinity, and the hand becomes uncanny. In mathematical terms, this can be represented by a negative value.” He adds that when a prosthetic hand that is near the bottom of the uncanny valley starts to move, the sensation of eeriness intensifies.The official translation on Tuesday is accompanied by an interview with Mori, who can look at the validity of his remarks 42 years later, when robotics has gone through so many developments. A counterpoint to the popularity of Mori’s essay has been the contention that the essay was an essay, after all, of limited scientific value.Mori said, “I have read that there is scientific evidence that the uncanny valley does indeed exist; for example, by measuring brain waves scientists have found evidence of that. I do appreciate the fact that research is being conducted in this area, but from my point of view, I think that the brain waves act that way because we feel eerie. It still doesn’t explain why we feel eerie to begin with.“ Mori said that pointing out the existence of the uncanny valley was intended as advice for people who design robots rather than a scientific statement itself.Mori said he still thinks that designers should steer clear of making robots too lifelike, falling into the valley. ” I have no motivation to build a robot that resides on the other side of the valley…Why do you have to take the risk and try to get closer to the other side?” He said he did not even find it interesting to develop a robot that looks “exactly” like a human.Mori spoke approvingly about Asimo as “invigorating,” a robot inviting positive feelings but appearing as different from humans.The two translators of the essay are Karl F. MacDorman, associate professor of human computer interaction at the School of Informatics, Indiana University. and Norri Kageki, a journalist who writes about robots. Explore further More information: spectrum.ieee.org/automaton/ro … s/the-uncanny-valleyspectrum.ieee.org/automaton/ro … n-the-uncanny-valley © 2012 Phys.Org Image: Wikipedia. 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.
(A) Illustration of a genuine quantum router. The control photon can be in arbitrary superposition states with coecients c0; c1 that determine the path of the signal photon. (B) The entanglement-based approach to implementation of a genuine quantum router. With a bit of pre-shared entanglement, the quantum router can be realized with linear optical devices. The control coecients c0; c1 are imprinted through operation on the control photon alone with a polarization rotator and a lter. The routing is realized with a polarization beam splitter (PBS) and a wave plate on the signal photon. Image from arXiv:1207.7265v1 [quant-ph] 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. Physicists build first single-photon router © 2012 Phys.org Explore further More information: Experimental demonstration of an entanglement-based quantum router, arXiv:1207.7265v1 [quant-ph] arxiv.org/abs/1207.7265AbstractWe report an experiment that demonstrates full function of a quantum router using entangled photons, where the paths of a single-photon pulse are controlled in a coherent fashion by polarization of another single photon. Through a projective measurement, we prepare the polarization of the control photon in arbitrary superposition states, leading to coherent routing of the target photon in quantum superposition of different paths. We demonstrate quantum nature of this router through optical measurements based on quantum state tomography and show an average fidelity of $(93.24pm 0.23)%$ for the quantum routing operation. The trick in routing quantum data is that reading the information from a signal that tells a router where to send data, causes that data or signal to be destroyed; that’s just how quantum mechanics works, so the ordinary way of routing data on a network won’t work. To get around that problem, the researchers used two of the special properties of quantum particles, namely, entanglement, whereby whatever happens to one, automatically happens to another and the fact that a particle is capable of representing two states at once (i.e. both 1 and 0).To build their router the team first generated a photon with superposition (one that has both horizontal and vertical polarization states); they then converted the photon to two entangled photons that also had superposition states. Then they treated one of the entangled pair as the control signal and the other as the data signal. When the control signal is read, and destroyed, the router gains the information it needs to know regarding which of two optical fiber cables to send the data signal, and thus, routes the data signal down the desired path.The researchers aren’t claiming they’ve come up with a solution for building a quantum Internet, as clearly their router is only capable of routing a single cubit, but it does demonstrate that routing quantum data is possible, and that’s something that until now, no one else has been able to do. And it also gives hope to researchers that someday a new and different type of quantum router will be created that really will allow for a true quantum Internet, and if that happens, data transmission will likely become so fast, that it will cease to be a topic of conversation. Citation: Chinese team builds first quantum router (2012, August 7) retrieved 18 August 2019 from https://phys.org/news/2012-08-chinese-team-quantum-router.html Journal information: arXiv (Phys.org) — With all the talk of quantum computers, little notice has been made of work on what is known as a quantum Internet, which is where data is sent across a web of computers via devices that work at the quantum, rather than atomic level, thereby increasing the speed of the whole system. The holdup at this point is in creating devices capable of routing such information. Now it appears that a team of physicists working from Tsinghau University in China have proven that it’s possible to do so. They have, as they describe in the paper they’ve uploaded to the preprint server arXiv, built a working quantum router capable of routing one cubit.
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. Researcher Pasi Lähteenmäki discussed the challenges he and his colleagues – G. S. Paraoanu, Juha Hassel and Pertti J. Hakonen – encountered in their study. Regarding their demonstration of the dynamical Casimir effect using a Josephson metamaterial embedded in a microwave cavity at 5.4 GHz, Lähteenmäki tells Phys.org that the main challenge in general is to get high-quality samples. In addition, Lähteenmäki adds, they had to ensure that the origin of the noise is quantum and not some unaccounted source of excess noise, such as thermal imbalance between the environment and the sample, or possibly leakage of external noise.Modulating the effective length of the cavity by flux-biasing the SQUID (superconducting quantum interference device) metamaterial had its challenges as well. “The pump signal needs to be rather strong, yet at the same time one wants to be sure that no excess noise enters the system through the pump line, Lähteenmäki notes, “and good filtering means high attenuation, which is a requirement contradictory to a strong signal. Also,” Lähteenmäki continues, “at 10.8 GHz the pump frequency is rather high – and at that frequency range both the sample and the setup is rather prone to electrical resonances which can limit the usable frequencies.” In short, the flux profile needs to be such that the pumping doesn’t counteract itself. In addition, trapping flux in SQUID loops can also become a problem, limiting the range of optimal operating points and causing excess loss.The researchers also showed that photons at frequencies symmetric with respect to half the modulation frequency of the cavity are generated in pairs. “In general, with frequency locked signal analyzers today the extraction of this correlation is not particularly problematic – especially since the low noise amplifier noise is not correlated at different frequencies,” Lähteenmäki explains. That said, issues related to data collection and averaging include amplifier gain drift and phase randomization of the pump signal (relative to the detection phase) if the state of the generator is changed. “The noise temperature of the low noise amplifier sets some limits to the amount of data that needs to be collected, especially in the case where one is operating in the regime of low parametric gain.” More information: Dynamical Casimir effect in a Josephson metamaterial, PNAS Published online before print February 12, 2013, doi:10.1073/pnas.1212705110 Journal information: Proceedings of the National Academy of Sciences Citation: Ex nihilo: Dynamical Casimir effect in metamaterial converts vacuum fluctuations into real photons (2013, March 8) retrieved 18 August 2019 from https://phys.org/news/2013-03-nihilo-dynamical-casimir-effect-metamaterial.html (Phys.org) —In the strange world of quantum mechanics, the vacuum state (sometimes referred to as the quantum vacuum, simply as the vacuum) is a quantum system’s lowest possible energy state. While not containing physical particles, neither is it an empty void: Rather, the quantum vacuum contains fluctuating electromagnetic waves and so-called virtual particles, the latter being known to transition into and out of existence. In addition, the vacuum state has zero-point energy – the lowest quantized energy level of a quantum mechanical system – that manifests itself as the static Casimir effect, an attractive interaction between the opposite walls of an electromagnetic cavity. Recently, scientists at Aalto University in Finland and VTT Technical Research Centre of Finland demonstrated the dynamical Casimir effect using a Josephson metamaterial embedded in a microwave cavity. They showed that under certain conditions, real photons are generated in pairs, and concluded that their creation was consistent with quantum field theory predictions. Copyright 2013 Phys.org All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of Phys.org. Light particles illuminate the vacuum Explore further Lastly, the team also found that at large detunings of the cavity from half the modulation frequency, they found power spectra that clearly showed the theoretically-predicted hallmark of the dynamical Casimir effect. “Large detunings imply low intensity of generated radiation,” notes Lähteenmäki. “This means long averaging times, so the system should be kept stable for a long period. Also, the system needs to be fairly resonance-free over a large range of frequencies to get decent data – and/or one needs to know the characteristics of these resonances and noise temperature of the low noise amplifier rather well.”Lähteenmäki points out that addressing these issues required a number of insights and innovations. “We combated amplifier drift by continuously switching the pump on and off, and recording the difference in the observed output power, suitable operating points were searched for using trial and error, and trapping the photon flux was eliminated by applying a heat pulse to the sample and letting it cool down again. The researchers also magnetically shielded the sample with a superconductive shield, and minimized the effect of losses by changing the coupling of the existing samples by making different valued vacuum coupling capacitors with focused ion beam (FIB) cuts.”However,” Lähteenmäki stresses, “our biggest issue – ruling out the source of classical noise as opposed to quantum noise – was accomplished primarily by characterizing the sample and the environment well” Thermal imbalance was ruled out by the symmetry of the sparrow-tail shape of the noise spectrum.It was essential for the scientists to clearly demonstrate that the observed substantial photon flux could not be assigned to parametric amplification of thermal fluctuations. “By characterizing the parametric gain with a network analyzer,” Lähteenmäki notes, “we found that in order to explain the amount of noise one gets, the device would need to have significantly higher gain than is observed if the only source of noise was thermal.” Moreover, confirming that photon pair creation is a direct consequence of the noncommutativity structure of quantum field theory was equally important. “Basically the experimental results fit the theoretical predictions rather well – and in the absence of other sources of noise, the theory implies that we should get no output from this sort of device. Since we see output consistent with the theoretical predictions, the conclusion was logical.”Moving forward, Lähteenmäki describes next steps in their research. “Instead of a continuous wave pump, we could have a straight flux line and feed it with a step-like flux pulse,” Lähteenmäki says. “This would allow the creation of an analogue to a black hole event horizon. In fact,” he adds, “we’re hoping to create an artificial event horizon in a metamaterial similar to the one used in our current research and study Hawking radiation originating from it. Also, it would be nice to be able to run experiments on Bell’s inequalities.” His personal interests, Lähteenmäki says, are fundamental quantum mechanics, quantum information and properties of the vacuum itself.”The obvious applications for these devices,” he notes, “come from quantum computation, and in general they may serve as components for multitude of sensitive measurements. I believe the interest towards low loss metamaterials is high and the field is just getting started. Our results show that these devices have potential and can offer a fruitful platform for many experiments and perhaps practical devices as well. Improving such devices – especially eliminating the losses and making them function more robustly – would allow them to create a general purpose component suitable for creating entangled microwave photon pairs, low noise amplification, squeezed vacuum, and other functions that can be very useful for quantum computation and general experiments in the quantum mechanics and in studying the vacuum.”Another possibility, Lähteenmäki adds, is to create a metamaterial which would allow them to stop signal propagation in the material entirely and allow them to resume it later. “This would act as a kind of slow light memory that would store the photon for later use.”Other areas of research might benefit from their study as well, Lähteenmäki says. “There are some connections to cosmology, the big bang, cosmic inflation, and other areas. These metamaterials could possibly offer an analogy to such events and serve as a platform to simulate the evolution of such conditions. Who knows,” he ponders, concluding that “perhaps we’d find clues to the mysteries of dark matter and dark energy or other fundamental questions from such systems.” (a) Equivalent electrical and mechanical circuits: the modulation of the Josephson inductance in the metamaterial by a magnetic φext varies the wave length λ with respect to the cavity length, which is analogous to modulating the effective length d of the cavity by mechanical means. The coupling capacitor is equivalent to a semitransparent mirror. (b) Schematics of the measurement setup. The metamaterial sample is a 4-mm-long coplanar waveguide with 250 embedded SQUIDs, each junction having a critical current of ~ 10 μA. The modulation of the flux through the SQUIDs is realized through a lithographically fabricated spiral coil underneath the metamaterial. (c) Resonant frequency ωres/2π vs. reduced magnetic flux φext/φ0 without the pump signal; the DC operating point for DCE experiments is denoted by a green circle. The inset displays the measured phase of the scattering parameter S11 while sweeping frequency, which yields d arg(S11)/dφext = d arg(S11)/dfÍdf/dφext . The steepness of the variation in the phase arg(S11) governs the effective “movement of the mirrors”. Copyright © PNAS, doi:10.1073/pnas.1212705110
NASA plots daring flight to Jupiter’s watery moon (Phys.org) —Scientists at NASA’s Jet Propulsion Laboratory (JPL) have been working on a device that may one day explore the underside of ice on Europa, Jupiter’s moon. NASA completed an early prototype of the rover it hopes will give us more information about Europa, with its abundant water and energy and chemistry. A National Geographic video shows the rover, called BRUIE (Buoyant Rover for Under-Ice Exploration) being taken for a run in Alaska. The team is interested in Europa, with its frozen, fissured surface and all. NASA’s notes on Europa tell us it is an icy world slightly smaller than Earth’s moon. A unique feature about Europa in the solar system is its global ocean of water in contact with a rocky seafloor. According to NASA, Europa could be a promising place to look for life beyond Earth. Europa’s surface is mostly solid water ice, extremely smooth and crisscrossed by fractures. Citation: Rover under-ice prototype may lead to Europa search (2014, June 25) retrieved 18 August 2019 from https://phys.org/news/2014-06-rover-under-ice-prototype-europa.html Explore further © 2014 Phys.org More information: solarsystem.nasa.gov/planets/p … Display=OverviewLongwww.nationalgeographic.com/astrobiology/ That last bit about an untethered vehicle operated through satellite link is a key part of their story. National Geographic described the moment when the engineers knew the satellite could work. “An electronic signal travels from NASA’s Jet Propulsion Lab in Pasadena, California, to a robotic rover clinging to the underside of foot-thick ice on an Alaskan lake. The rover’s spotlight begins to glow.” The milestone involves a quest to develop an unmanned vehicle that may one day plumb the icy reaches of Europa.NASA’s Galileo mission explored the Jupiter system from 1995 to 2003, with flybys of Europa. It obtained the closest images to date of the moon’s fractured surface. Attracting attention were strange pits and domes that suggested ice possibly slowly turning over, or convecting, due to heat from below. Last year, NASA announced evidence from researchers using the Hubble Space Telescope that Europa might be actively venting plumes of water into space. A National Geographic video indicates the NASA effort is interesting not only because of Europa but because of the advances the Jet Propulsion Laboratory team made in developing its early prototype. This, after all, is a roving, untethered vehicle being shown under the Alaskan ice. When the probe reaches Europa, its search for life may be modeled on a trial such as this one. With explanations by astrobiologist Kevin Hand, the video shows testing around the frozen lakes of Barrow, Alaska. The scientists turned to Alaska’s ecosystems where lakes freeze over every year, representative of life in an extreme environment, and helping to guide the NASA team in assessing if a world like Europa could harbor life. They cut a hole in the ice, put the Rover underneath the ice and handed over control to engineers at the Jet Propulsion Laboratory.”So we think this was the first time ever, that an underwater, under-ice, untethered vehicle has been operated through satellite link.” 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.
As Game of Thrones barrels to its conclusion, impatient fans can find torrents of rumors and alleged leaks as to who will rule Westeros when the curtain closes. We will not be linking to these flagrant would-be spoilers, but we can offer proprietary information that spoils nothing: The psychological personality profiles that drive the motivations of the remaining contenders. TIME is currently running a scientifically crafted survey that determines how closely your personality aligns with each of five major characters—Cersei, Daenerys, Tyrion, Arya and Jon Snow. The questions, compiled for TIME by a team of research psychologists, are all drawn from established social and behavioral science and measure your attitudes toward leadership and self-regard. But to pull this off, there was one dataset that we had to collect ourselves: meaningful information on the personalities of the characters themselves. So this project began with a low-profile stage in which devoted fans took our survey on behalf of the five characters, answering each question as they believe the characters would have answered. This phase was conducted before the current season began, so the profiles do not reflect anything that has happened recently, but rather their general tendencies in how they feel and behave. Read the whole story: TIME
It was sheer curiosity that led to a beautiful serendipity which has now become a mission for author-classical singer Vikram Sampath, who has created an archive of Indian classical music, carnatic music, folk music and speeches from the pre-Independence era, digitised them and built a national treasure online.The Archive of Indian Music(AIM) is a museum of sorts to listen to the golden voices of bygone era. The recordings span 1902 to 1952 and boast of many known and unknown names like Bhimsen Joshi, Devika Rani, Abdul Karim Khan, Hirabai Barodekar and Madurai Mani Iyer among others. It can be accessed at Also Read – ‘Playing Jojo was emotionally exhausting’www.archiveofindianmusic.org.‘I was curious to listen to the voice of legendary singer Gauhar Jaan (the first Indian voice to be recorded in 1902) while I was writing a book on her. It was during the research that I realised there were old gramophone recordings of known and unknown singers in abominable condition,’ Sampath, 33, told in an interview. ‘I started collecting them and reached out to record collectors. Some generous people donated. This is how the process began accidentally. One thing led to the another by chance,’ he said, adding he has around 100,000 records for digitising, of which 10,000 have already been transferred. Also Read – Leslie doing new comedy special with NetflixThe BITS Pilani alumnus has penned three well-researched books on history and music: Splendours of Royal Mysore, My Name is Gauhar Jaan – The life and times of a musician and Voice of the Veena: S. Balachander, a biography.The pilot of the site went online in January. After receiving an overwhelming response from music connoisseurs, the team is now working on making the final version user friendly.There was never any intention of minting money through the site, Sampath said.To sustain and monetise the site, he has plans to create audio-visual exhibitions across India.
In memory of the renowned actor-filmmaker Rituparno Ghosh, India Habitat Centre’s film club collaborates with the Directorate of Film Festivals and Calcutta Presidency College Alumni Association to pay a tribute to the director with a retrospective of his choicest works. Remembring Rituparno, the on-going series of screenings includes interactions with scholars and critics well versed with his works. Spanning over a forthnight, these film screenings have a plethora of cinematic marvels for the film buffs in the capital. It will showcase Also Read – ‘Playing Jojo was emotionally exhausting’ Chokher Bali- A passion of play, Shobh Charitro Kalponik (All characters are imaginary), Abohomaan( The eternal), Memories in march, and end with a bang with the winner of Special Jury National Award in 2012, Chitrangdha, on 17 July. Kicking off with Unishe April (19 April) on the first of July, the film club screened Ashukh(Malaise) and the National Award winning best feature film in 2003, Shubho Muhurat on 2 and 4 July, respectively. Head over and experience Ghosh’s cinematic excellence through his films.
The News Services Division (NSD) of All India Radio has launched a year-long celebration to mark the 75th year of news transmission in Tamil, Marathi and Gujarati. NSD started news transmission in various languages in the wake of World War- II way back in 1939. Since its inception to date, NSD has contributed immensely in taking news to every small corner of the country. From a modest 27 news bulletins in 1939-40, All India Radio today puts out over 650 bulletins daily for a total duration of over 56 hours in about 91 languages/dialects. Also Read – ‘Playing Jojo was emotionally exhausting’NSD has played a pivotal role in creating awareness among the people through the most difficult period of nation building during the post independence era. The language units have contributed immensely in creating awareness by providing correct and objective news. Some of the newscasters and newsreaders-cum-translators have over the years become household names for the people of that language. On the occasion 14 veteran news casters in Tamil, Telugu, Gujarati and Marathi were felicitated in presence of board of members, director general and Prasar Bharti’s chief executive officer. Also Read – Leslie doing new comedy special with NetflixMarking the completion of 74 years of language units, number of activities have been proposed to celebrate all round the year, panel discussion on the contribution of language units, various workshops for Language Units will take place, Organising various cultural programme for year long platinum jubilee celebrations. Also a Souvenir will be printed during the year with articles related to radio broadcasting written by eminent writers, broadcasters and media personnels.
Artist Puneet Kaushik presents his latest series of works titled Daraar – Beneath the Faultline at India Art Fair from January 29 to February 1. The works reflect no longer something remote, but abstractions of life itself. Kaushik’s bodies of work are aesthetic and material dimensions of extractions, accumulation, territorialisation, condensations and fractures underlying the visible reality of urban life. They are neo-expressionist, collages of kaleidoscope materials and techniques – wire mesh, paint, bead work, carpet craft, line drawings and organic dyes that bring to the surface histories of tension that exist just beneath the ordinariness of everyday lived humanity. Also Read – ‘Playing Jojo was emotionally exhausting’Known for using methodologies and traditional techniques incorporating tribal and folk art like the works are of steel wire mesh, woven hibiscus and coffee stains on paper, natural dyes, tufting the carpet technique, dabkha and bead work.In his works, Puneet has been successfully driven by a single idea or concept, injecting an element of exploration, with materials offering their own guiding agency; and in this respect he marks a posture of difference. Also Read – Leslie doing new comedy special with NetflixThe guiding concept behind the majority of the works has been around the idea of Identity, the dealing with the self. The beauty and the ugliness within the surface; the superficial and the deeper self, textured and layered by different circumstances where it is rare to be in a position to penetrate into the real self.Puneet has been intrigued by age-old traditional techniques like knitting, crochet and embroidery, rooted deep in our cultures as a means of talking about the self. For example, the traditional Tibetan technique using a process of embroidery where two or more beads are stitched in one go was normally done not only to enhance the jewellery or crown but also to thicken the surface in order to protect and keep one warm.Where: National Gallery of Modern Art When: On till March 29
In the past few weeks, Prime Minister Narendra Modi has been facing flak for not addressing the gross improprieties committed by certain senior leaders in his party. In fact on Sunday, he was criticised by opposition parties for failing to speak about the controversy involving the alleged links between former Indian Premier League Chairman Lalit Modi, Union External Affairs Minister Sushma Swaraj and Rajasthan Chief Minister Vasundhara Raje during his national radio address. However, what many opposition leaders seem to have forgotten in their rabid urge to criticise the prime minister is that he used his fortnightly radio address to focus on the girl child once again, calling for women to be gifted insurance policies on Raksha Bandhan. Selfies aside, the prime minister has taken a strong initiative on this front. Also Read – Working on improving tiesThe insurance schemes initiated by the Centre, including Pradhan Mantri Jeevan Jyoti Bima Yojana, which requires a person to pay a premium of just Rs 330 per annum to get a life insurance of Rs 2 lakh and the PM Suraksha Bima Yojana, aimed at providing accidental insurance of Rs 2 lakh at a premium of Rs 12 per annum, are steps taken in the right direction. Allied with the Atal Pension Yojana, which offers a pension of up to Rs 5,000, these schemes, if implemented, could go some way in addressing gross crimes against women like female foeticide. Data released in April by the Women and Child Development ministry state that approximately 2,000 girls die every day in India from abortion, starvation, poisoned or killed after birth. According to a survey by the Centre for Social Research, “the fear and burden of dowry,
Kolkata: The Kolkata Municipal Corporation (KMC) has taken up a massive Green Energy Development initiative, under which it will light up all its buildings including borough offices, health units, community halls and schools, with solar lights.”We have made plans to light up all our buildings using solar lights, with electricity bills shooting up by leaps and bounds. Solar photovoltaic (PV) cells will be set up on the roof of these buildings. We have already installed solar lights in as many as three parks in the city and the electricity bills have witnessed a significant dip,” a senior official of KMC’s lighting department said. Also Read – Rain batters Kolkata, cripples normal lifeThe lighting department has already forwarded a proposal in this regard to the civil department, which has started the task of examining the strength of the buildings.They will submit a report about whether the buildings of the civic body can withstand a solar PV panel weighing around 20 kg, which the lighting department plans to install on the roofs. The KMC will begin with its 16 borough offices and then will gradually proceed with its health units, community halls and schools. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed”Work will progress as per availability of funds,” the official added. The KMC has already undertaken work for illuminating 16 parks in the city with solar lights. The state government has already sanctioned Rs 52 crore for the project. It may be mentioned that three parks in the city – Deshapriya Park, Maddox Square Park and Hazra Park have already been lit up with solar lights. Deshbandhu Park, Santosh Mitra Square, College Square, Md Ali Park, Subhas Sarobar Park and many others are lined up in the list as well.It may be mentioned that a solar power plant installed at Deshapriya Park has reduced the electricity expenses by a huge margin. Around Rs 36,000 per month is being saved now at Deshapriya Park.
Kolkata: A woman lawyer in the city registered a complaint with the police against a veterinary doctor whom she accused of negligence leading to the death of her pet.The incident took place at Kankurgachi. The complainant, Sagarika Chowdhury alleged that her pet died while being sterilised by the doctor at her chamber. On the basis of the complaint, the police have started a probe. It was learnt that Chowdhury went to doctor Aparajita Chakraborty in the Kankurgachi area for sterlising her pet cat on May 26. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataAccording to her complaint, the woman lawyer alleged that she was later informed that sterlisation was performed on her pet and she could take it to her house. When Chowdhury went to see her pet, she found that it had not gained consciousness. Hence the woman decided to stay back at the doctor’s clinic till the animal regains consciousness instead of taking it home. When the woman had been waiting at the doctor’s clinic, she was asked to pay the dues in cash. Chowdhury then went to a nearby ATM kiosk to withdraw money. Also Read – Lightning kills 8, injures 16 in stateWhen she returned to the clinic, the complainant found that her pet was kept inside a bucket which was used to bring the pet to the chamber. The woman told some of the staff members of the clinic that she wanted to meet the doctor. She was told by some staffers that doctor had left the clinic already and hence she would not be able to consult her. Being concerned over the health condition of her pet, the woman asked one of the staff members as what happened to her pet. The staff member asked the woman to take her pet home as the clinic would be shut down soon. The woman was also advised not to bring the cat out of the bucket as it would take around six hours for the animal to regain consciousness. The woman returned home. She opened the cover of the bucket after a few hours and touched the animal. She found that there were blood stains on its head. She then rushed to the clinic again but failed to save the life of her pet. She found that the clinic was already shut and the pet died. Chowdhury alleged that her pet was absolutely fine when it was taken to the doctors’ chamber for the operation. She alleged that the doctor’s negligence led to the death of her pet and lodged a complaint with the Phool Bagan police station demanding a probe into the incident.
Chapra (West Bengal): A man has been arrested after a consignment of gold biscuits and US dollars was seized from his possession near the India-Bangladesh border in Nadia district, police said. Based on a tip off, BSF personnel were waiting at Hridaypur area near the India-Bangladesh border on Sunday when they intercepted the man, Buddhadeb Biswas, near the fence. Gold biscuits and bars worth over Rs 36 lakh and US dollars amounting to Rs 22.88 lakh were seized by the BSF from his possession. The seized items were handed over to the Excise Department, the police said.
Darjeeling: A special border personnel meeting between India and China was held at Nathula in Sikkim on Thursday, to commemorate the 92nd anniversary of the foundation of the People’s Liberation Army (PLA).On invitation from the PLA, a delegation of the Indian Army comprising officers and soldiers took part in the celebration. The PLA troops interacted with the visiting Indian delegation and presented a cultural programme. As a gesture of goodwill, the Indian side also reciprocated with traditional cultural events to mark the occasion. Also Read – Rs 13,000 crore investment to provide 2 lakh jobs: MamataDelegations from both sides also met at Kongra La in North Sikkim. The ceremonial meeting was headed by Brigadier-ranked officials from both sides. The celebrations provided an opportunity to both sides to display their rich culture. “Such interactions go a long way in ensuring better understanding between both armies and have contributed towards achieving common goals of peace and tranquility along the borders,” stated an Army release.
The term “Potemkin Village” was coined after a local Russian legend in which an 18th-century military governor of Crimea, Grigory Potemkin, devised a plan to impress Catherine the Great, who announced an official visit to his province. Potemkin, who was also known to be the Empress’ lover, created a number of fake villages to cover the empty landscapes, to convince Catherine that he was managing a prosperous region, filled with colorful settlements and a booming economy.The Potemkin Village. Photo by Gregor Sailer – PhotographyThe Potemkin Village. Photo by Gregor Sailer – PhotographyAccording to the story, the villages were just models made of wood, and they were even transported from one place to another, just before the Empress of Russia would pass by them.AdChoices广告inRead invented by TeadsThe Potemkin Village. Photo by Gregor Sailer – PhotographyAlthough modern historians claim that this ludicrous story is very much exaggerated, the term stuck to describe using means of deception to falsely present a situation better than it actually is.The Potemkin Village. Photo by Gregor Sailer – PhotographyRecently, it became the title of an interesting publication made by Gregory Sailer, an Austrian photographer who focused on fake urban settlements used for various purposes ― from military training to entertainment.The Potemkin Village. Photo by Gregor Sailer – PhotographySailer traveled the world searching for fake settlements ― from China and Russia to the United States and Sweden ― documenting ghost towns, all of which were built for everything else except for people to live in.The Potemkin Village. Photo by Gregor Sailer – PhotographyFor example, in the Chinese city of Gaoqiao, there is a theme park built as a Dutch town for Asian tourists who wish to feel like they’re in Europe.The Potemkin Village. Photo by Gregor Sailer – PhotographyHalfway across the globe, there is another fake town that tries to look familiar. Swedish automobile industry giant, Volvo, has its own testing ground which is built as a replica of New York’s Harlem neighborhood.The Potemkin Village. Photo by Gregor Sailer – PhotographyOn the other hand, the so-called Junction City in the Mojave desert feels like an exact replica of a Middle-Eastern settlement, with Arabic low-rise buildings and a mosque.The Potemkin Village. Photo by Gregor Sailer – PhotographyWhen it’s not used for simulating warfare in the Iraqi desert, this military compound looks like a town evacuated in a hurry. In an interview for Wired, Sailer pointed out the U.S. army training ground:“It’s fascinating that such enormous efforts are invested in constructing such sites, for millions and billions of dollars or euros, just to prepare people for war.”The Potemkin Village. Photo by Gregor Sailer – PhotographyThe Potemkin Village. Photo by Gregor Sailer – PhotographyRelated Video: Drone captures abandoned mountain top villageThe Potemkin Village. Photo by Gregor Sailer – PhotographyThe Potemkin Village. Photo by Gregor Sailer – PhotographyThe Potemkin Village. Photo by Gregor Sailer – PhotographyThe Potemkin Village. Photo by Gregor Sailer – PhotographyThe Potemkin Village. Photo by Gregor Sailer – PhotographyThe Potemkin Village. Photo by Gregor Sailer – PhotographyCheck out Gregor Sailer’s website to see more of his work.The Potemkin Village. Photo by Gregor Sailer – PhotographyIn Russia, however, the well-known tactic of masking rundown buildings with a fake facade is still very much in use.The Potemkin Village. Photo by Gregor Sailer – PhotographyAmong Sailer’s photographs, one can find real contemporary versions of Potemkin villages in the Russian town of Suzdal, where local officials decided to tidy up a bit by putting draped banners over dilapidated buildings, to welcome President Vladimir Putin.Read another story from us: The Amazing Construction of the Statue of Liberty in PhotosTo expose the nature of these giant props, Sailer photographed the cardboard and wooden buildings from all sides, deconstructing the illusion piece by piece, thus creating mesmerizing landscapes, all of which serve the purpose of generating fantasy ― whether it involved war, tourism, or car crashes.Sailer’s collection of photographs titled Potemkin Village can be purchased online, while his work remains continuously exhibited all year, in different venues and art shows, like the International Photography Festival in Arles.
HudsonMonday, Aug. 1210:04 a.m. Central St. MVA, property damage.10:26 a.m. Christian Ave. Disturbance, general.2:46 p.m. Highland Commons E. Animal complaint.5:37 p.m. Manning St. Larceny/forgery/fraud.Tuesday, Aug. 135:23 a.m. Summer St. MVA, property damage.1:15 p.m. Wilkins St. Larceny/forgery/fraud.4:58 p.m. Central St. Suspicious activity.5:39 p.m. Washington St. MVA, property damage.10:20 p.m. Felton St. Suspicious activity.11:28 p.m. Ridge Rd. Suspicious activity.Wednesday, Aug. 1410:43 a.m. Broad St. Disturbance, general. 4:45 p.m. Technology Dr. Larceny/forgery/fraud.6:10 p.m. Technology Dr. Suspicious activity.6:28 p.m. Fort Meadow Dr. Suspicious activity.7:21 p.m. Main St. Disturbance, general.8:53 p.m. Felton St. Threats.Thursday, Aug. 152:35 a.m. Apsley St. Suspicious activity.7:40 a.m. Church St. Disturbance, general.3:43 p.m. Main St. Suspicious activity.4:59 p.m. Cottage St. Suspicious activity.8:52 p.m. Washington/Park Sts. MVA, property damage.9:56 p.m. Chestnut St./Kelly Ln. Suspicious activity.Friday, Aug. 165:25 p.m. Main/Wilkins Sts. MVA, property damage.5:35 p.m. South St. Suspicious activity.6:47 p.m. Lakeside Ave. Suspicious activity.Saturday, Aug. 1711:21 a.m. Central St. Erratic operator.11:57 a.m. Grove St. Suspicious activity.2:42 p.m. Technology Dr. Animal complaint.7:17 p.m. Brigham St. Suspicious activity.Sunday, Aug. 182:33 a.m. Central St. Suspicious activity.4:09 p.m. Loring St. Suspicious activity.4:56 p.m. Brigham St. Disturbance, general.7:03 p.m. Washington/Brigham Sts. Nosie complaint.8:30 p.m. Four Bridges Rd. Vandalism.9:18 p.m. Huron Dr. Suspicious activity.10:39 p.m. Central St. Noise complaint.The information from the police log is obtained directly from the official records maintained at each police station in our circulation area. It contains arrests and samplings of police activity. Those arrested are innocent until proven guilty. The Community Advocate will publish news of acquittals upon notification and a copy of court-issued documentation.