Micromacro entangled cat states could one day test quantum gravity

first_img Journal information: Physical Review Letters In order to extend quantum effects to the macroscopic level, physicists are working on creating entanglement between a macroscopic and microscopic system. This situation is very similar to that of the entanglement between the quantum state of the macroscopic cat and that of the microscopic decaying nucleus. So far, micro-macro entanglement has been experimentally demonstrated in optical systems, and is currently being pursued in other areas, such as electro-mechanical and opto-mechanical systems.In a new study published in Physical Review Letters, physicists Roohollah Ghobadi, et al., have proposed a method for generating optomechanical micro-macro entanglement. One of the most intriguing outcomes of bringing quantum effects to the macroscopic level using this approach is that it could allow researchers to test for wave function collapse due to quantum gravity, which is predicted to occur on a much shorter timescale than wave function collapse due to environmentally induced decoherence.”Our proposal allows for observation of the genuine macroscopic superposition of massive objects,” Ghobadi told Phys.org. “It also looks promising to test some collapse models.”The proposed method involves storing one component of an entangled state of light (consisting of just one or a few photons) in a mechanical resonator (consisting of billions of atoms). During this process, the initial microscopic entangled state of photons is amplified with a strong coherent beam, the photons are converted into phonons, and then the entangled states are retrieved. This approach makes it possible to create optomechanical “cat states,” in which the quantum states of the photons and phonons are in superposition. The researchers write that the scheme is realizable with current technology, and if realized, would be the second demonstration ever of optomechanical entanglement. To test proposals for quantum gravity-induced wave function collapse, future experiments could be performed that compare the collapse time (estimated to be on the order of microseconds) to the collapse time of environmentally induced decoherence (on the order of milliseconds).”It is interesting to do the proposed experiment for different masses in order to distinguish the decoherence due to a collapse model from conventional environmentally induced decoherence,” said coauthor Christoph Simon, Physics Professor at the University of Calgary.In addition, by varying other factors such as the amplification and the number of phonons, researchers could use this method to look for other types of deviations from quantum physics in this little-explored regime of micro-macro entanglement and superposition.”One possible direction is to apply the method proposed here to create cat states in other systems,” Ghobadi said. “It is also interesting to look at its application in quantum information processing.” (Phys.org) —In Schrödinger’s famous thought experiment, a cat’s quantum state becomes entangled with the quantum state of a decaying nucleus, resulting in the odd situation that the cat is both alive and dead at the same time. The thought experiment was originally intended to convey the absurdity of applying quantum mechanics to macroscopic objects, but recently physicists have been questioning whether “quantum” effects such as entanglement and superposition may apply on all scales. 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: R. Ghobadi, et al. “Optomechanical Micro-Macro Entanglement.” PRL 112, 080503 (2014). DOI: 10.1103/PhysRevLett.112.080503 © 2014 Phys.orgcenter_img What if quantum physics worked on a macroscopic level? Citation: Micro-macro entangled ‘cat states’ could one day test quantum gravity (2014, April 16) retrieved 18 August 2019 from https://phys.org/news/2014-04-micro-macro-entangled-cat-states-day.html Proposed setup for generating optomechanical “cat states,” a form of micro-macro entanglement in which the quantum states of photons and phonons are in superposition. Credit: R. Ghobadi, et al. ©2014 American Physical Society Explore furtherlast_img read more

Study shows one reason why pigeons so rarely crash

first_img More information: Pigeons trade efficiency for stability in response to level of challenge during confined flight, C. David Williams, PNAS, DOI: 10.1073/pnas.1407298112 AbstractIndividuals traversing challenging obstacles are faced with a decision: they can adopt traversal strategies that minimally disrupt their normal locomotion patterns or they can adopt strategies that substantially alter their gait, conferring new advantages and disadvantages. We flew pigeons (Columba livia) through an array of vertical obstacles in a flight arena, presenting them with this choice. The pigeons selected either a strategy involving only a slight pause in the normal wing beat cycle, or a wings-folded posture granting reduced efficiency but greater stability should a misjudgment lead to collision. The more stable but less efficient flight strategy was not used to traverse easy obstacles with wide gaps for passage but came to dominate the postures used as obstacle challenge increased with narrower gaps and there was a greater chance of a collision. These results indicate that birds weigh potential obstacle negotiation strategies and estimate task difficulty during locomotor pattern selection. Explore further Feral pigeon (Columba livia) in flight. Credit: Alan D. Wilson/Wikipedia/CC BY-SA 2.5 © 2015 Phys.org City dwellers know that pigeons are some of the best flyers around, unlike robins and other birds, pigeons rarely collide with cars, buildings, trees or any other obstacle. That skill has not gone unnoticed—scientists and engineers have been working for years to duplicate their abilities. In this new effort, Williams and Biewener taught some of their tamed specimens to fly through a corridor to get to a meal, then introduced obstacles and high speed cameras to find out how it is that the birds are so good at avoiding objects in their path.The obstacles were plastic pipes, placed vertically some distance apart from one another. To pass between the pipes, the birds had to scrunch themselves a bit, but how they did so, the researchers found, depended on how far apart the pipes were. They noted that when the pipes were at least a half a wing length apart, the birds lifted their wings as if to flap as they approached the obstacle, but then held them steady, above their heads as they passed between the pipes, then flapped down as soon as they were through—a technique that led to very little loss of altitude, which meant it was quite efficient. But if the pipes were moved closer together, they pulled their wings into their body, a less efficient approach, but one much less likely to result in wing damage. To make sure the first approach was not merely coincident based on where the wings were when the birds arrived at the obstacle, the researchers filmed them multiple times, finding the same result each time.Because the birds used two different techniques for allowing them safe passage through the pipe obstacles, based on what they observed as they approached, the researchers believe that choosing which technique to use was a deliberate act, which meant the birds somehow made a choice of which technique to use, just before they passed through—very impressive, especially when noting that birds, except for some such as crows or magpies, are not generally known for their smarts. Citation: Study shows one reason why pigeons so rarely crash (2015, March 3) retrieved 18 August 2019 from https://phys.org/news/2015-03-pigeons-rarely.htmlcenter_img Journal information: Proceedings of the National Academy of Sciences Researchers conduct study to determine impact of using drones to study birds 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. (Phys.org)—A pair of researchers with Harvard University has uncovered one of the secrets behind pigeons’ impressive flight abilities. In their paper published in Proceedings of the National Academy of Sciences, David Williams and Andrew Biewener describe how they videotaped some of the birds flying through an obstacle course they made, and what they found when they examined the footage.last_img read more

Curiosity rover finds possible evidence of ancient explosive volcanoes on Mars

first_imgThis low-angle self-portrait of NASA’s Curiosity Mars rover shows the vehicle at the site from which it reached down to drill into a rock target called “Buckskin.” Bright powder from that July 30, 2015, drilling is visible in the foreground. Credit: NASA/JPL-Caltech/MSSS Curiosity finds rocks that might point to a continental crust on Mars 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. (Phys.org)—A large team of researchers from across the U.S. studying data sent back from Mars by the Curiosity rover has found evidence of tridymite, a type of mineral associated with explosive volcanoes here on Earth. In their paper published in Proceedings of the National Academy of Sciences, the team describes how the rover found the sample, the testing it underwent, and why it might lead to rethinking the early history of the Red planet. More information: Richard V. Morris et al. Silicic volcanism on Mars evidenced by tridymite in high-SiOsedimentary rock at Gale crater, Proceedings of the National Academy of Sciences (2016). DOI: 10.1073/pnas.1607098113AbstractTridymite, a low-pressure, high-temperature (>870 °C) SiO2 polymorph, was detected in a drill sample of laminated mudstone (Buckskin) at Marias Pass in Gale crater, Mars, by the Chemistry and Mineralogy X-ray diffraction instrument onboard the Mars Science Laboratory rover Curiosity. The tridymitic mudstone has ∼40 wt.% crystalline and ∼60 wt.% X-ray amorphous material and a bulk composition with ∼74 wt.% SiO2 (Alpha Particle X-Ray Spectrometer analysis). Plagioclase (∼17 wt.% of bulk sample), tridymite (∼14 wt.%), sanidine (∼3 wt.%), cation-deficient magnetite (∼3 wt.%), cristobalite (∼2 wt.%), and anhydrite (∼1 wt.%) are the mudstone crystalline minerals. Amorphous material is silica-rich (∼39 wt.% opal-A and/or high-SiO2 glass and opal-CT), volatile-bearing (16 wt.% mixed cation sulfates, phosphates, and chlorides−perchlorates−chlorates), and has minor TiO2 and Fe2O3T oxides (∼5 wt.%). Rietveld refinement yielded a monoclinic structural model for a well-crystalline tridymite, consistent with high formation temperatures. Terrestrial tridymite is commonly associated with silicic volcanism, and detritus from such volcanism in a “Lake Gale” catchment environment can account for Buckskin’s tridymite, cristobalite, feldspar, and any residual high-SiO2 glass. These cogenetic detrital phases are possibly sourced from the Gale crater wall/rim/central peak. Opaline silica could form during diagenesis from high-SiO2 glass, as amorphous precipitated silica, or as a residue of acidic leaching in the sediment source region or at Marias Pass. The amorphous mixed-cation salts and oxides and possibly the crystalline magnetite (otherwise detrital) are primary precipitates and/or their diagenesis products derived from multiple infiltrations of aqueous solutions having variable compositions, temperatures, and acidities. Anhydrite is post lithification fracture/vein fill. To date, planetary scientists believe that the geological history of Mars has been very tame compared to our own home planet—this is, they believe, because Mars does not have shifting plates that lead to big earthquakes and explosive volcanoes. Evidence of volcanoes on that planet to date has shown them to be of the steady flowing type such as those that led to the creation of the Hawaiian Islands—they form due to melting hot mantel plumes just below the surface. But now, a mineral find might mean scientists will have to rethink the ancient history of Mars.The Curiosity rover has been rolling around in Gale crater since 2014, and last year it began digging and studying samples from an area known as Marias Pass. The research team noted that the makeup of the rocks there appeared to suggest silica, so they subjected them to X-ray analysis. That showed the samples to have a very high level of tridymite, which was both surprising and thought provoking because it conflicted so sharply with the history that has been written for the planet—they suggest it appears likely that the mineral was created somewhere else on the planet and was carried to the crater basin. This is because prior research has suggested parts of the basin were once filled with water—that Martian lake would have been filled by streams and rivers coming from distant places bringing with them and depositing sediments, some of which could have been material ejected or formed by explosive volcanoes. But if Mars did have such volcanoes, the team wonders, how did they form in the absence of plate tectonics?The findings by the team and their theories are likely just the first stage of what will be many projects aimed at reevaluating Mars’ history, or looking for ways that tridymite might be created without the intense heat of a violent volcanic eruption.center_img Citation: Curiosity rover finds possible evidence of ancient explosive volcanoes on Mars (2016, June 14) retrieved 18 August 2019 from https://phys.org/news/2016-06-curiosity-rover-evidence-ancient-explosive.html Journal information: Proceedings of the National Academy of Sciences © 2016 Phys.org Explore furtherlast_img read more

Pop theatre Manto flavour of NSD fest

first_imgThe crossover between literature, performance, classicism and its modern interpretations will be on showcase at the 15th Bharat Rang Mahotsav, the National School of Drama’s (NSD) annual theatre festival.The festival will celebrate the legacy Saadat Hasan Manto, William Shakespeare and popular theatre in the perspective of the modern Indian stage.Announcing the 15-day theatre gala, NSD chairperson Amal Allana said the festival will bring to the Capital and twin venue of Jaipur a total of 87 plays, lectures, interactions, offsite projects and special packages. It will open with Also Read – ‘Playing Jojo was emotionally exhausting’Atmakatha, a two-hour play directed by Vinay Sharma, featuring former Bollywood actor Kulbhushan Kharbanda. It will mark the actor’s return to the stage, Allana said. ‘The wider variety of plays this year has allowed us to package them into categories. The ‘Manto section’ has six plays adapted from stories by Manto and the section on Shakespeare will explore the ‘inter-cultural influence on the dramatist’ with seven productions,’ Allana said, adding: ‘The focus will be on popular theatre that evolved from the Parsi form of theatre in the second half of 19th century.’ The 450 entries from which 87 were shortlisted were from across regions and genres that were not always ‘dependent on the government for support’. Also Read – Leslie doing new comedy special with NetflixThe Indian panorama with 11 productions and 52 other performances — adaptations, re-visitings, improvisations, devised plays and traditional renditions — will reflect contemporary theatre practises. The Shakespeare panorama will play host to the likes of indigenous improvisations of King Lear, a solo performance from Turkmenistan, an Assamese adaptation of Julius Caeser, a Hindi makeover of Twelfth Night, Piya Behroopia that played at the Globe Theatre in London last season, Footsbarn Theatre’s Indian Tempest as physical theatre. Wendy Jehlen of the US will present excerpts from Hamlet, Macbeth, Othello and Titus Andronicus in a choreographed non-verbal piece as The Knocking Within.A Malayalee adaptation, Yamadoothu: After the Death of Othello in Malayalam from Kerala, based on Shakespeare’s Othello will also be staged. Pointing to the trends in Indian contemporary theatre, Amal Allana said: ‘the trend to go back to traditional forms of theatre has waned’.‘We don’t have to go back to folk theatre and traditional theatre to sustain contemporary theatre. Plays are being staged as performances and devised scripts. There is more exchange and effort between theatre people because of greater a sense of participation and lack of original scripts,’ Allana said.She said: ‘The complexity of new theatre has brought in wake more non-verbal plays and physical theatre’. NSD director Anuradha Kapur said ‘there was a flowering of another kind of script that were meant to be read. We are reading scripts and performing them as well’. Bharat Rang mahotsav will feature plays divided into several categories.last_img read more

I would be very happy if Kaminey 2 happens

first_imgShahid Kapoor’s Haider with Vishal Bhardwaj is ready to come out, but that is not enough for the actor. His wish is that the filmmaker should make Kaminey 2 with him.While reports are doing the round that Shahid is, in fact, already a part of Kaminey 2, the actor said: ‘I would be very happy if Kaminey 2 happens.’ Released in 2009, Kaminey starred Shahid in a double role and he won accolades for his performance from all quarters. It also starred Priyanka Chopra and it brought out the news of the affair the two actors had, which lasted for a few months after the movie released. The actors, however, still maintain that they are in good terms with each other. Also Read – A fresh blend of fame‘I had an amazing experience with Vishal sir working on Kaminey and now Haider. I just hope he casts me in his next film and I hope that this film is Kaminey 2,’ the 33-year-old said here Wednesday on the sets of reality show Cine Stars Ki Khoj.In fact, Bhardwaj has already locked a story. ‘He has an amazing story and I think everyone should tell him to make it because he is difficult to convince. But he has a story and a romantic version of Dhan te nan also. I have been telling him he should do it, but he is a filmmaker and he has his own thoughts,’ he added.An adaptation of William Shakespeare’s play Hamlet, Haider also stars Shraddha Kapoor. The film will hit theatres on  2 October.last_img read more

Welcome planned for Pakistan hockey team cancelled after Peshawar attack

first_imgA grand welcome planned for Pakistan’s hockey team which won a silver medal in Champions Trophy was on Tuesday called off after a brazen Taliban attack on a military-run school that killed at least 160 people, mostly children.The Pakistan Hockey Federation said the ceremony has been cancelled following the attack on the Army Public School on Warsak Road in Khyber Pakhtunkhwa’s Peshawar city. The ceremony was planned to welcome the players who took Pakistan to the final of the just-concluded tournament in India after a gap of 16 years. Also Read – Khel Ratna for Deepa and Bajrang, Arjuna for JadejaThe players were to be driven in a motorcade to Lahore after their return home via the Wagah Border. The federation said the ceremony would be held at a suitable time. The team lost to Germany in the final. In one of the most gruesome attacks on children anywhere in the world, at least six Taliban militants stormed the school and went classroom-to-classroom shooting indiscriminately.At least 160 people, most of them children, were killed in the attack, which was a reaction to Pakistan military’s campaign against the militants.last_img read more

Gujs junior health min UP MLA down

first_imgAfter Gujarat Assembly Speaker, couple of IAS officers, Gujarat University Vice Chancellor, now Gujarat’s Minister of State for Health Shankarbhai Chaudhary has been tested positive. While, Vijay Mishra, a Samajwadi MLA from Gyanpur has also been tested positive for H1N1.last_img

Bengal CM remembers Swami Vivekananda on death anniversary

first_imgKolkata: West Bengal Chief Minister Mamata Banerjee today remembered Swami Vivekananda on his 116th death anniversary and urged the people to live up to the ideals the spiritual leader espoused. “On this day, the great philosopher, Swami Vivekananda attained Mahasamadhi. Remembering him on this solemn occasion. Let us strive to live up to the ideals he espoused, Banerjee wrote on her Twitter handle. Swami Vivekananda, who passed away on July 4 in 1902, played an important role in the spiritual enlightenment of the masses. He spread the Vedanta philosophy in the West and established the Ramakrishna Math and Ramkrishna Mission to serve the poor. “He taught the world the true meaning of Hinduism: universal brotherhood,” Banerjee said.last_img read more

Aggressive driving a reflection of surrounding culture

first_imgAggressive driving behaviour is a reflection of a person’s surrounding culture, both on the road and on a broader social level, says a study.The findings suggest that some countries and cultures may be more susceptible to aggressive or competitive driving behaviours due to their social environment, and that improvements in that arena would also be seen in driving behaviour.“The choice to be competitive versus cooperative always starts with culture, by the influences around us and the way other people behave, ‘said one of the researchers Haizhong Wang, assistant professor of transportation engineering at Oregon State University in the US.  Also Read – ‘Playing Jojo was emotionally exhausting’“And it’s clear there’s a role for education and experience, where studies have shown the value of young drivers participating in driver education programmes and receiving positive guidance from their parents and peers,” Wang noted.The study also implies that different social conditions might ultimately translate into better drivers.However, these dangerous behaviours are becoming a worldwide phenomenon of almost epidemic proportions partly as a reaction to overcrowded road networks, the researchers said. Also Read – Leslie doing new comedy special with NetflixThe findings, published in the journal Procedia Engineering, showed that such behaviour is more pronounced in men than in women.The research was done with drivers in China where competitive driving is very common. The problems in China as it becomes increasingly crowded with drivers, however, reflect similar concerns at varying levels around the world, Wang said. In this analysis, the researchers concluded that drivers in congested situations generally believed that the chaotic traffic state was responsible for their competitive behaviour and they had no option other than to compete for space, the right-of-way, and gain advantages through speed and spacing.In simple terms, it was right and proper that they should try to keep up with or get ahead of traffic; that was the example being set for them, and they drove that way because everyone else did.However, the study also suggested that “personality traits draw on and are influenced by aspects of one’s social environment.” It is prevalent in India too where the surroundings play an important part.last_img read more

Weather likely to improve from today mercury set to dip further

first_imgKolkata: The weather condition in the city will improve from Wednesday, leading to a further drop in temperature, predicted the Regional Metereological Centre at Alipore on Tuesday. Meanwhile, Sandakphu witnessed mild snowfall on Tuesday, for the first time this winter season. It was a light drizzle accompanied by snowfall.The weather office also predicted that the city’s sky may remain cloudy from Wednesday morning and there will be a little drizzle in some parts of the city as well as South Bengal districts. The districts may witness bright sunshine from Thursday, as the cyclonic storm ‘Phethai’ has been weakened. Also Read – Rain batters Kolkata, cripples normal life”As the cyclonic condition clears, the mercury will start to drop further from Wednesday. There will be light drizzle in some parts of the city, even on Wednesday. The cyclonic storm has lost momentum due to the constant blowing of the northwesterly wind in the state. The wind will intensify further, as soon as the sky gets cleared,” a senior official of the Alipore Met office said. It may be mentioned that the city and South Bengal districts witnessed light to moderate rainfall on Tuesday, as was predicted. ‘Phethai’ has been hovering in the coastal areas of Odisha after it turned into a low-pressure zone. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedIt may be mentioned that during last week, the minimum temperature had shot up as moisture in the air had been rising after the formation of a low pressure trough over Bay-of-Bengal. The mercury had started climbing due to the incursion of moisture since last week. The districts like North 24-Parganas, South 24-Parganas, Hooghly and Howrah received light rainfall overnight, while districts like East Midnapore, West Midnapore, Purulia and Bankura received light to moderate rainfall on Tuesday. The districts also experienced strong gusty winds. According to a weather official, the temperature may dip to 9 degree Celsius during Christmas this year. Traffic movement in various parts of the city was slow on Tuesday morning, due to the drizzle. The temperature on Tuesday remained around 16 degree Celsius. “The temperature on Wednesday may hover around 14 degree Celsius, while it will drop further from Thursday. As the clouds start disappearing from Wednesday, the mercury will slide further down,” the weather official said.last_img read more