(PhysOrg.com) — “One of the many reasons people study ultracold gases is for their potential as model quantum systems,” Deborah Jin tells PhysOrg.com. “There is a need to model quantum many-body systems because a lot of important physics – from condensed matter and material physics to nuclear and particle physics – increasingly require an understanding of complicated quantum behavior. Ultracold gases can possible provide that through models we can interact with, helping to close the gap between what we can describe theoretically and what actually happens.” Copyright 2010 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 This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Physicists work to understand atomic collisions important to ultracold quantum gasses Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
Citation: Engineers build time cloak that hides messages in laser light (2014, December 1) retrieved 18 August 2019 from https://phys.org/news/2014-12-cloak-messages-laser.html Explore further 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 team of engineers at Purdue University has succeeded in building a time cloak based on dual laser broadcast communications channels sent through a common medium. In their paper published in the journal Optica, the team describes how they improved on earlier work to create a time cloak that allows for hiding data in high-speed data communications. ‘Cloaking’ device uses ordinary lenses to hide objects across continuous range of angles Most people have heard of a cloaking device, it’s a means of covering an object so as to prevent it from being seen. Less well known are time cloaks, which hide events rather than objects. A team of engineers at Purdue has been investigating this idea and last year, came up with a way to transfer data that was hidden, by time cloaking, across a communications channel. The drawback was that the approach was too successful, the data couldn’t be read by anyone. Now, the team has improved their cloaking approach to the extent that it allows data to be time cloaked for transmission, and uncloaked by those that know how, all while keeping the data cloaked (hidden) from everyone else’s perspective.A time cloak works by masking evidence of the existence of an event. One way to do it is to control the flow of photons streaming from a laser. The idea is to insert data into a stream in a way that appears to the casual observer as steady, but in fact was interrupted to allow for data insertion, then resumed. Only those in the know beforehand would realize that data had ever existed in the stream. But, the catch is that those in the know must have a means for extracting that data—that’s what the team at Purdue has now developed.The device works by means of two communications channels based on lasers with two different frequencies. One of the frequencies is normal, in that it’s not time cloaked. The second is time cloaked and thus events that occur in it are hidden, except from those that know how to access them. The light from both channels travels down the same length of fiber cable, allowing someone who knows about the cloaked channel to tap in to the correct one to gain access to the data it holds. This approach allows those in the know to access hidden data, and also to fend off interlopers hoping to disrupt the communications.Besides being useful as a security measure, the researchers believe their technique could help improve high-speed data transmissions in the near future. © 2014 Tech Xplore Basic outline of temporal cloak. (a) Waveform progression for multiwavelength cloak. Blue and red lines denote the intensity in the channels to be cloaked and to receive the data, respectively. Roman numerals represent various points in the circuit: I, input to first phase modulator; II, after quarterTalbot dispersion; III, at event plane just prior to event modulation; IV, at event plane immediately after modulation; V, before compensating quarterTalbot dispersion; VI, at output. Only the red channel is impacted by the data modulation, which is an alternating zero–one sequence in this example. (b) Experimental setup. Boxes at the input and output show differences between the multiwavelength cloak (“WDM Experiment”) and data-as-input cloak (“Data Experiment”). Blue fibers and Bragg gratings signify anomalous dispersion, whereas red represents normal dispersion. CFBG, chirped fiber Bragg grating; SMF, single-mode fiber; DCF, dispersion-compensating fiber. Credit: Optica, Vol. 1, Issue 6, pp. 372-375 (2014) DOI: 10.1364/OPTICA.1.000372 More information: Temporal cloaking for data suppression and retrieval, Optica, Vol. 1, Issue 6, pp. 372-375 (2014) dx.doi.org/10.1364/OPTICA.1.000372AbstractRecent research on time cloaking has revealed a fascinating approach to hide temporal events from an interrogating optical field, by opening up and subsequently closing intensity gaps in a probe beam. Experiments thus far have demonstrated temporal cloaking of nonlinear interactions and high-speed optical data. Here we report a temporal cloak with the new capability not only to hide optical data, but also to concurrently transmit it along another wavelength channel for subsequent readout, masking the information from one observer while directing it to another. Additionally, the cloak succeeds in passing modulated data unscathed through a scrambling event, providing a new form of tampering resistance. Both examples launch a paradigm shift in temporal cloaking: instead of using time cloaks primarily to disrupt communication, we show how they can also improve data transmission, in turn greatly widening the range of possible applications in telecommunications.
© 2015 Phys.org Citation: New group seeks to timeline the Anthropocene—when humans became the dominant force on Earth (2015, April 3) retrieved 18 August 2019 from https://phys.org/news/2015-04-group-timeline-anthropocenewhen-humans-dominant.html (Phys.org)—A team of four scientists has published a Perspectives piece in the journal Science outlining their arguments for reaching back further in time than others have suggested for the beginning of the Anthropocene—a geologic epoch defined by the impact of homo sapiens on planet Earth. William Ruddiman, Erle Ellis, Jed Kaplan and Dorian Fuller suggest that current arguments that point to modern exploits overlook the huge impact of forest clearing and farming many thousands of years ago. Clouds over Australia are shown. Credit: NASA
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. © 2019 Science X Network A team of researchers with members from Norway, Austria, Russia and Germany has found a kind of bacteria that oxidizes methane. In their paper published in Proceedings of the National Academy of Sciences, the group describes their findings and suggest their work could lead to progress in combating global warming. Credit: CC0 Public Domain Defusing the methane bomb—we can still make a difference Citation: Bacteria that oxidizes methane found in common soil (2019, April 9) retrieved 18 August 2019 from https://phys.org/news/2019-04-bacteria-oxidizes-methane-common-soil.html Journal information: Proceedings of the National Academy of Sciences Scientists have reached consensus that global warming is happening, and that it is because humans continue to pump greenhouse gases into the atmosphere. The main culprit is carbon dioxide, but there are other greenhouse gases making their way into the atmosphere, as well—one of them is methane. Humans produce methane naturally, via flatulence, as do animals. It also results from production of rice and other crops, and released it during oil extraction. To combat global warming, we stop emitting methane, or find a way to remove it. In this new effort, the researchers report a natural way to remove methane from the air by supporting a type of bacteria that oxidizes it.Scientists have suspected for many years that one or more types of bacteria oxidize methane because testing has shown that methane levels drop in places where there is soil present.The researchers report that they have isolated a type of bacteria that lives in soil and oxidizes methane: Methylocapsa gorgona. It is very common and is found all around the globe. It can also live on very low concentrations of the gas. On the downside, the researchers found that it is also quite fragile, and activities like farming can kill it.The researchers suggest that M. gorgona could possibly be an effective methane sink if used properly. They also acknowledge that creative ideas are required before such applications could come to fruition. They go so far as to suggest the bacteria might be genetically altered to force it to consume more methane. But in the meantime, the discovery could lead to changes in farming practices that prevent the destruction of the bacteria, allowing vast stretches of land to once again remove methane from the air. More information: Alexander T. Tveit et al. Widespread soil bacterium that oxidizes atmospheric methane, Proceedings of the National Academy of Sciences (2019). DOI: 10.1073/pnas.1817812116 Explore further
How paradoxical are our lives are! We live in a conservative society in a modern country. There are some who dare to experiment with unconventional things while there are others who prefer to remain behind closed doors.Madhav Mehta belongs to the former category. This 22-year-old theatre artist has come out with his directorial debut, titled Kasturba Panda ki Pantie. The 75 minute production is presented by Epic Shit Entertainment.The play is the story of Kasturba, the frustrated wife of a failed businessman named Ranjan Panda. Since his business isn’t doing good, he plans to rent out parts of his Sundar Nagar home but does not find too many takers. One day Kasturba gets to know that superstar Salman Khan will be coming to the famous Sundar Nagar Diwali mela. Kasturba, being a huge Sallu fan, rushes to the mela to catch a glimpse of the superstar. As she stretches on her tiptoes to get a good view of the man, her petticoat and panties slip off. And all of a sudden, the number of parties interested in taking up Ranjan’s rental offer skyrockets. Also Read – ‘Playing Jojo was emotionally exhausting’The play is a one-man show, played by Farhad Colabavala who dresses as all the different characters in the play. It is a narration followed by dialogue. ‘It’s a solo performance by Farhad which explores the state of a modern, conservative, married Indian woman in Delhi. I have known Farhad for four years and we have done theatre together. I adapted this play only keeping him in mind,’ said Madhav.’Doing this one-man show has been challenging, but overall a very enriching experience. Switching between characters without losing the flow has been a learning experience, which has helped me evolve as an actor. It’s been a really fun process, working with such a great team of people backed by an absolutely hilarious script,’ said Farhad. Also Read – Leslie doing new comedy special with NetflixMadhav says his play is not meant for the general theatregoers. ‘To begin with, the story is not in your usual play format. This format requires the play to be much tighter, with acting at a different plane to hold the attention of the audience. It belongs to an adult comedy genre and also caters to feminist thoughts at the same time,’ he said.And that must be noted.DETAILAt: Akshara Theatre, Baba Kharak Singh Marg, Connaught Place When: 22-24 February Timings: 4 pm and 8 pm Tickets: Rs 400
Indian Ocean, India’s first Indo-rock fusion band are into their 25 years of existence now. Marking this event, the band is now up with their new album Tandanu. After Sushmit Sen, one of the founder members, left the band, Indian Ocean have collaborated with biggies in music. We got talking with Amit Kalim, the drummer and percussionist of the band. Here are excerpts…Being Amit Kilam, how do you feel associated with the band?Feels great. I have been associated with the band for 20 years now. I am really very happy. It gives me immense satisfaction contributing to the band. I feel lucky. Also Read – ‘Playing Jojo was emotionally exhausting’Tell us something about your new album TandanuThis is the seventh album of our band. It is formed in collaboration with some great musicians of our country. The album have seven songs and each song features one musician with whom we have collaborated. It is a fresh piece of music with no influence from the bollywood music.This is your first album after Sushmit Sen left the band. What difference you guys felt working without him? We didn’t miss Sushmit. After he left, we have a new guitar player Nikhil Rao. Everything was new for him and for us as well. We had to do a lot more of practice than we used to do while Sushmit was there. We started from the basics again. This time the idea was fresh. It was a whole new album with a whole new sound and a new face. It was the time we kept reinventing ourselves and worked really very hard. Also Read – Leslie doing new comedy special with NetflixYou are collaborating with biggies in music for your new album. How was the experience?Working with all the big star Vishwa Mohan Bhatt, Vishal Dadlani, Selva Ganesh, Karsh Kale, Shankar Mahadevan, Shubha Mudgal and Kumaresh Rajagopalan was a real experience. These guys are really amazing. I lack words to express how it felt.25 years of existence of Indian Ocean now. How has the journey been so far?The journey was fantastic. Inspite of all the ups and downs we faced throughout years, we are left with no regrets. I just wish the journey goes on for years after. How would you guys define your musical philosophy?Practically we don’t have any philosophy. Called for music we don’t make music for public. We make music for ourself and hope that the public likes it. We just have to be happy and than only we can be true and can make really good music which everyone will accept.In our country how easy or difficult it is to make a mark in music?Well, according to me it is as easyor as difficult as you make it to be. In India a lot of things have changed. More people can come up with their talent. There are a lot new festivals which can help you showcase your talent. You have to be ready for a long process. Nothing is spontaneous. What/ Who would you take as your greatest inspiration?Calling it inspiration, I cannot take a single name. There are a lot of people whom I met throughout the journey of life. All of them inspires me in one way or another. Any act of kindness or cruelty by anyone do leaves a vital mark in my life. What lies next in the pipeline?There are no plans yet. Tandanu was a very big project which left us with a very tight schedule. We haven’t planned anything for future now.
Kolkata: Intellectuals have urged people not to get swayed by rumour and instigation. They were talking to the media at Press Club on Wednesday afternoon. They had gathered under the banner of “Esho sampriti jao bibhajan.”Nrisingha Prasad Bhaduri, noted scholar, said united fights should be put up immediately to stop misinterpretation of Ramayana. “The term Hindu has been grossly misinterpreted and wrong messages have been sent to the people,” he said. Also Read – Heavy rain hits traffic, flightsHossenur Rahaman, noted historian, said Bengal has set an example of communal harmony in South East Asia, because of great people like Rabindranath and Nazrul, along with many more who have consolidated peace and harmony.Poet Subodh Sarkar said it is most unfortunate that “they” (meaning BJP) have given arms in the hands of children. “The people should not get swayed by the rumours,” he maintained.Suvaprasanna said that for many generations, Ram Navami was observed in Bengal in some households. “But there were no weapons. I saw my mother offering Puja to Ram. It was observed peacefully,” the eminent artist said. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedPoet Joy Goswami said efforts should be made to establish “peace in society.” “Peace can be established through music, poetry and exchange of views. Like-minded people should be united against evil,” he said.Litterateur Abul Basar said he had come to attend the meeting as he finds that “Mamata Banerjee is a symbol of communal harmony.” He said the political and social scenario in India has drastically changed after the demolition of Babri Masjid. “There are some who try to let loose Hindus against the Muslims and vice-versa, to reap benefit out of the chaos,” Basar added.River expert Kalyan Rudra said the need of the hour is to restore peace in society. “There are some who are trying to destabilise society and we should fight against them wholeheartedly to restore normalcy,” he said.
Kolkata: A woman was killed and three of her family members along with two others received injuries, some of them critically when the private car they were traveling in hit a dumper.The incident took place in Jamuria area of Asansol on early Wednesday morning. All the injured victims were rushed to a hospital in Asansol. According to the hospital sources, two of the injured victims are stated to be very critical. The deceased has been identified as Sudeshna Sarkar. Also Read – Heavy rain hits traffic, flightsPolice said Jayanta Sarkar, a resident of Andal’s Bahula area was taking his mother Dipali Sarkar to Asansol for consulting a doctor on early Wednesday morning. His wife Sudeshna and his 6-year-old son were also accompanying them. It was learnt that there were two of his neighbours travelling in the car one of who was driving the car when the accident took place.According to police, the accident took place at Tapasi when the car rammed into a dumper. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe frontal portion of the car was damaged in the accident. Locals heard a loud thud and rushed to the spot to find that the injured persons were wreathing in pain inside the car, a portion of which was damaged due to the intensity of the accident. After being informed, police reached the spot and rescued the victims some of whom were taken to a hospital in Ranigunge while the others were rushed to a hospital in Asansol.According to the preliminary investigation, police suspect that the accident might have occurred when the driver had fallen asleep. Police are, however, looking into all possible angles into the accident. The circumstantial evidences suggest that the car was running at a high speed when it hit the dumper coming from the opposite direction. Sudeshna Sarkar was taken to a hospital in Ranigunge along with two others while the doctors pronounced her brought dead. Other three members of the Sarkar family have been undergoing treatment in an Asansol hospital.Police have seized both the vehicles while the driver of the dumber has fled the spot immediately after the accident. A probe has been initiated by the police in this regard.
Kolkata: West Bengal Chief Minister Mamata Banerjee on Tuesday greeted Shiv Sena chief Uddhav Thackeray on the occasion of the party’s 52nd Foundation Day. “Heartiest greetings to Uddhav Thackeray Ji and all Shiv Sena workers on the 52nd Foundation Day of their party,” Banerjee tweeted. Banerjee, who is playing an active role in promoting the idea of a federal front together with regional party leaders to counter the Bharatiya Janata Party (BJP) in the 2019 general elections, has spoken positively of the Maharashtra-based party’s decision to contest all future elections independently. In spite of being the BJP’s ally in both Maharashtra and at the Centre, the Shiv Sena and the saffron outfit have been at loggerheads for several months. It has also backed Delhi Chief Minister Arvind Kejriwal’s ongoing sit-in protest.