Explore further Physicists have investigated little-known solutions to Maxwell’s equations, in which light beams can be linked and knotted in various configurations. Credit: Irvine and Bouwmeester. ©2008 Nature. Citation: Physicists hope to tie light beams in knots (2008, September 12) retrieved 18 August 2019 from https://phys.org/news/2008-09-physicists_1.html Physicists William Irvine of New York University and Dirk Bouwmeester of the University of California, Santa Barbara, and Leiden University in The Netherlands have published a study in Nature Physics on their analysis of knotted light. The scientists looked at the physical properties of knotted light and discovered that it can be experimentally generated using circularly polarized laser beams.In some little-known solutions to Maxwell’s equations, all the electric and magnetic field lines form circles that are all linked to each other. These loops of field lines can be used to construct the donut shape of a torus. In such a scenario, each circle wraps around the torus once, and no two circles cross each other. Smaller tori could then be nested within larger ones, filling three-dimensional space with circles of light beams. These solutions differ from any known existing form of light because of the intricate knotted structure, the physicists told PhysOrg.com. As they explained, this structure is based on the Hopf fibration, which was introduced in 1931 to mathematically investigate the structure of spheres in four and higher dimensions, a topic that seemingly has nothing to do with light. After investigating knotted light’s properties, the physicists determined that they could use laser fields to create the structures. Starting with a single-pulsed beam of circularly polarized light, and tightly focusing the beam, it should be possible to create various shapes of looped light beams. By using holographic techniques and a spatial light modulator, the shape and profile of the looped light could also be controlled. These same techniques have recently been used to produce Airy beams, which are light beams that don’t spread out as they propagate.Currently the physicists are preparing for an experimental realization of the new solutions either using electromagnetic radiation in the optical regime, i.e. light, or in the microwave regime. The main challenge will be to deal with ultra-short pulses of radiation in order to create a broad spectrum of frequencies as needed for the construction of the light knots. Because knotted light beams have both beamlike properties and unique unexplored properties, the physicists predict that creating the beams could have applications in several areas. These could include applications in plasma confinement, atomic particle trapping, manipulating cold atomic ensembles, and generating soliton-like solutions in nonlinear media.More information: Irvine, William T. M. and Bouwmeester, Dirk. “Linked and knotted beams of light.” Nature Physics, Vol. 4, September 2008, pp. 716-720.Copyright 2008 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. Usually, light beams shine in a straight line, with the possible exception of light being bent by gravity. But scientists are now investigating how to make light beams into looped and knotted configurations. The possibility for these structured light beams arises from some curious solutions to Maxwell’s equations, which describe the fundamentals of electricity and magnetism. Multicolored light twists in new knotted ways 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.
Explore further Citation: Creating power from water (2011, March 25) retrieved 18 August 2019 from https://phys.org/news/2011-03-power.html Image credit: J. Am. Chem. Soc., 2009, 131 (11), pp 3838-3839. DOI: 10.1021/ja900023k More information: www.suncatalytix.com/tech.html This technology, which can be used with gray water, could be used to power a mini power plant, that would be about the size of a refrigerator, according to the researchers. Of course, those plans could change, since this research is really only it its early stages. By next year the team expects to be able to power a small home with only roughly a bottle and a half of water.While specifics of the deal have not been made public at this time, The Tata Group’s mission is to being basic needs and other essential resources to low-income peoples, and the best guess is that this technology will involve that market. 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) — Creating power from water. I bet when I say that you picture a dam or a large turbine being pushed by hundreds of thousands of gallons of water, all rushing at tremendous speeds. It is a cool, and accurate, image of how most power comes from water. That is not to say that it is the only way that power can come from water. © 2010 PhysOrg.com Researchers at the The Tata Group have been working with Daniel Nocera, an MIT scientist and founder of SunCatalytix, have found a new way to coax power out of water. If you’re wondering how that was accomplished here are the basics. The research team placed an artificial sheet of artificial cobalt- and phosphate-coated silicon into a jar of water. This produced an effect similar to photosynthesis. The splitting of hydrogen from water was used to generate power from the sun. Interestingly enough, this technique was able to produce more power than the current generation of solar panels. Catalyst could power homes on a bottle of water, produce hydrogen on-site (w/ Video)
Journal information: Science A power law is where a relationship between two quantities exists that can be described mathematically where one measurement is directly related to the outcome of another. In their perspective the authors describe it as related via an exponent which can be mathematically described. One example is where the surface area of a sphere is firmly fixed to its radius, i.e. the area increases proportionally as the radius does. In such cases, its scalable, it doesn’t matter how large or small the sphere is, its surface area can still be calculated using the same formulaic relationship. It’s also meaningful, i.e. the relationship formula can be used to actually calculate sphere surface areas.In their perspective, the authors use the relationship between the metabolic performance of an organism and its body size, which biologists describe using allometric scaling, a power law, to make their assertions. Research has shown that using such a formula allows scientists to calculate the second when obtaining the first through measurement, regardless of body size, a clear and useful thing when studying virtually any organism.In their perspective, however, the authors point out that not all areas of science are so compliant, which leads to all manner of assumptions regarding outcomes that may or may not be true. One prime example is when researchers collect data points and find they can draw a line though them, which suggests a correlation. Unfortunately, quite often other lines could have just as easily been drawn, indicating there was no correlation at all. The point here is that in scenarios where the power law cannot be applied, researchers are often left to make educated guesses, going on little more than intuitive leaps based on past experience. This is especially important when it is a practicable impossibility to obtain a reasonably large sample size.They also point out that many instances occur in research where the power law is applied in ways that don’t actually make sense. For example, if a line is drawn though a set of data points showing correlation, it won’t matter much if that line doesn’t offer any real insight into what is being demonstrated.Because of such scenarios, the authors conclude that it might behoove the scientific community, both researchers and readers of scientific papers alike, to apply some bit of skepticism to such claims when they are made. 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. Explore further Citation: A frank discussion of the power law and linking correlation to causation (2012, February 10) retrieved 18 August 2019 from https://phys.org/news/2012-02-frank-discussion-power-law-linking.html An example power-law graph, being used to demonstrate ranking of popularity. To the right is the long tail, and to the left are the few that dominate (also known as the 80-20 rule). Image: Wikipedia. (PhysOrg.com) — Michael Stumpf a mathematics professor at Imperial College in London, and Mason Porter a lecturer at Oxford have teamed together to write and publish a perspective piece in Science regarding the inexact science of trying to apply the power law to situations in science where it’s not always easy to show a direct link between correlation and causation, a key problem they say, in much of the science that is conducted today. © 2011 PhysOrg.com Libel case against the scientific journal Nature begins More information: Critical Truths About Power Laws, Science 10 February 2012: Vol. 335 no. 6069 pp. 665-666. DOI: 10.1126/science.1216142The ability to summarize observations using explanatory and predictive theories is the greatest strength of modern science. A theoretical framework is perceived as particularly successful if it can explain very disparate facts. The observation that some apparently complex phenomena can exhibit startling similarities to dynamics generated with simple mathematical models (1) has led to empirical searches for fundamental laws by inspecting data for qualitative agreement with the behavior of such models. A striking feature that has attracted considerable attention is the apparent ubiquity of power-law relationships in empirical data. However, although power laws have been reported in areas ranging from finance and molecular biology to geophysics and the Internet, the data are typically insufficient and the mechanistic insights are almost always too limited for the identification of power-law behavior to be scientifically useful (see the figure). Indeed, even most statistically “successful” calculations of power laws offer little more than anecdotal value.
© 2018 Phys.org A team of astronomers from Germany and Hungary has detected a new group of co-moving young stars. The newly found group is located in the Upper Centaurus Lupus (UCL) section of the Scorpius–Centaurus Association. The finding is reported in a paper published December 29 on the arXiv pre-print repository. The Scorpius–Centaurus Association (Sco-Cen) is an association of massive young stars of spectral type O and B. Located at a mean distance of 400 light years away from the Earth, it is the nearest region of recent massive star formation. One of its subgroups is the UCL, which is almost entirely covered by star-forming regions, except for a small area in the south-eastern corner of this subgroup. Now, a group of researchers led by Siegfried Röser of the Heidelberg University in Germany, has found a compact, young moving group of stars in this particular area of UCL.The newly detected group, named V1062 Sco Moving Group (V1062 Sco MG for short), was found by analyzing the data available in the Gaia-TGAS proper motion catalog in late 2016. Next, the researchers conducted follow-up observations of V1062 Sco MG using the FEROS instrument at the MPG/ESO 2.2 m Telescope in La Silla, Chile, in order to confirm the discovery and with the aim of determining fundamental parameters of this group.”We detected a hitherto unknown moving group or cluster in the Upper Centaurus Lupus section of the Sco-Cen OB-association,” the scientists wrote in the paper.According to the study, V1062 Sco MG is a co-moving group of 63 young stars at the edge of the UCL section, some 570 light years away from the Earth. “Altogether, we found 12 members with confirmed radial velocities and parallaxes, 31 with parallaxes or radial velocities, and 20 candidates from the convergent point method,” the paper reads.However, although the stars of this group are generally young, they are not coeval, as their ages range from four to 25 million years. At the moment, the researchers cannot explain this age spread.The authors of the paper emphasized that the newly found group is strongly co-moving and its one-dimensional velocity dispersion is less than 1.0 km/s. When it comes to the masses of the members of the group, they range from 0.7 to 2.6 solar masses.Although the researchers identified dozens of members of V1062 Sco MG, still many stars of this group remain undetected. The authors of the study believe that the Gaia Data Release 2 (from ESA’s Gaia satellite), expected to be published in April 2018, will reveal new and fainter members of the group. Further studies of V1062 Sco MG and other co-moving groups could provide important information about the process of star formation in associations. Explore further The location of the V1062 Sco Moving Group (red circle). Credit: Röser et al., 2017. 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. Astronomers identify dozens of new OB-type stars in the Cygnus OB2 stellar association Citation: Astronomers discover a new co-moving group of stars (2018, January 9) retrieved 18 August 2019 from https://phys.org/news/2018-01-astronomers-co-moving-group-stars.html More information: A new compact young moving group around V1062 Sco, arXiv:1712.10143 [astro-ph.SR] arxiv.org/abs/1712.10143AbstractAims. We are searching for new open clusters or moving groups in the Solar neighbourhood. Methods. We used the Gaia-TGAS catalogue, cut it into narrow proper motion and parallax slices and searched for significant spatial over-densities of stars in each slice. We then examined stars forming over-densities in optical and near-infrared colour-magnitude diagrams to determine if they are compatible with isochrones of a cluster. Results. We detected a hitherto unknown moving group or cluster in the Upper Centaurus Lupus (UCL) section of the Sco-Cen OB-association at a distance of 175 pc from the Sun. It is a group of 63 co-moving stars with ages of less than 10 to about 25 Myr. For the brightest stars, which are present in the Gaia-TGAS catalogue the mean difference between kinematic and trigonometric distance moduli is about 0:01 mag with a standard deviation of 0.11 mag. Fainter cluster candidates are found in the HSOY catalog, where no trigonometric parallaxes are available. For a subset of our candidate stars, we obtained radial velocity measurements at the MPG/ESO 2.2-metre telescope in La Silla. Altogether we found twelve members with confirmed radial velocities and parallaxes, 31 with parallaxes or radial velocities, and 20 candidates from the convergent point method. The isochrone masses of our 63 members range from 2.6 M_Sun to 0.7 M_Sun.
Vivek Vinay Natya Sangit, conceptualised by Devajit Bandopadhyay and to be performed by Riddhi Bandopadhyay and Sujoy Prasad Chatterjee, took all back to Swami Vivekananda’s valuable lessons on the concepts of universal truth and social awakening. Held to commemorate the 150th birth anniversary of Swami Vivekananda, the event at NSD’s Adhikalp brought together some of the best minds in the Capital.Chatterjee, one of the best known elocutionists and theatre artistes from Kolkata, enthralled the audience with the recitals from Vivekananda’s poetry as Riddhi Bandopadhyay performed the vocal renditions connected to the verses. Bengal has a very distinctive musical heritage and traditionally music pervades all cultural practices, especially celebrations. Continuing with that legacy, Chatterjee points out that Vivekananda was a trained musician himself and his songs were heavily influenced by Bangla Natyasangeet. What was performed was a selection of songs from the Sangit Kalpataru that connects Vivekananda’s verses along with the songs, like the song Shango Amar Dhula Khela from the play Bhisma by DL Roy was performed alongside the poem My Play is Done. Chatterjee, who is all set to perform his first international solo show at Singapore on 29 May, added that the celebrations did not only focus on music, the teachings of the great man are inherent in beautiful connect of poetry and songs.
Doordarshan National will be unfurling its vibrancy in the grand colors of purple and pink with a fresh palette of programming from Monday, 17 November. The channel will be re-dedicated to the nation with the byline Doordarshan National – Desh Ka Apna Channel. The channel will focus on traditional family values – Rishtey Nation Before Self – Rashtra Gaurav and Trustworthiness – Dilon Mein Vishwas.The fresh look and feel, with which these shows are slotted, is aimed at recreating the legacy of Doordarshan in providing quality Information, Education and Entertainment. Also Read – ‘Playing Jojo was emotionally exhausting’The new programmes that are to be launched on the channel are Happy Homes – Khatte-meethe jeevan ke rang , starting from 17 November and slotted at 7pm is a light comedy of unity in diversity when people speaking different languages and from different regions live together in a colony. At 7:30 pm Khwabon ke darmiyan – Sach aur sapno se jhoojhti zindagi, is to be aired. This show will highlight the struggle to bridge the gap between dreams and reality for women in changing social context. Also Read – Leslie doing new comedy special with NetflixAt 8 Pm Khamosh sa afsana – Jidd aur armano ka fasana, has a fine cast of talented stalwarts like Tom Alter, Roopa Ganguly, M.K. Raina who are the central characters in a story depicting the struggle of a daughter fighting to balance her work and managing her disabled parents. It will be followed by Zindagi ek Bhanwar – Rajneeti me mahila ka raaj. This is a political drama aims at reaching out to the aspirations of society and desiring changes in quality of life. At 9:30 pm – Dard Ka Rishta – Badalte Sambandhon ki kahani will be starting from Monday. followed by Jab Jab Bahar Ayee – Janmon ka bandhan ya bandhish. A serial which touches upon a dilemma of husband and wife trying to keep their family together and finding happiness not withstanding their personal differences.Doordarshan National is also building their weekend prime-time with two shows Janmon ka Bandhan and Prakriti.Janmon ka Bandhan’ – Insaani rishton ka tana bana starting 21 November, airing Friday to Sunday at 7 pm is a women-centric family drama while Prakriti– Kudrat ko bachane ki jung tracks the story of an ideal forest officer who endeavours to save nature. It is set against the backdrop of scenic Jim Corbett Park. It will air from 22 November, every Sat and Sun at 8:30 pm.
Darjeeling: The ban on sale of certain non-organic vegetables and fruits in Sikkim by the Sikkim Democratic Front government, has started to take a toll on the vegetable and fruit market of Siliguri. It has also drawn flak from different quarters in Sikkim. The All Sikkim Trader’s Association has also decided to seek legal recourse against the ban.In a bid to further boost the image of it being an organic state, the Sikkim government led by Chief Minister Pawan Chamling, has announced a ban on sale of certain non-organic vegetables, fruits, spices and condiments and a cereal from April 1. Also Read – Heavy rain hits traffic, flightsA Home department, government of Sikkim order, dated March 31, 2018, regulated the sale of certain non-organic agricultural and horticultural commodities, with an objective to “prevent risk to the health of human beings, animals and environment” and “deemed it expedient that such commodities shall be liable to be seized and disposed of.” Amidst scarcity of vegetables and fruits coupled with skyrocketing prices, the enforcement team of the Horticulture department, government of Sikkim, has been conducting raids in markets in Gangtok and surrounding areas, having confiscated non-organic vegetables worth more than Rs 4 lakh. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedHuge pits were dug at Majhitar, Rangpo and East Sikkim and the confiscated vegetables and fruits were dumped in those pits on Wednesday.”This move to ban non-organic produce will definitely lead to a food scarcity and there is nothing much that we can do. Owing to short supply of vegetables, prices have skyrocketed, that too in this peak tourist season. We have no other option than to go to court against this,” stated Lakpa Sherpa, vice-president, All Sikkim Trader’s Association. Sherpa informed that Sikkim farmers cannot meet the requirements, especially during tourist season. More than 95 percent of the vegetables and fruits are brought in from Siliguri in West Bengal.The ban has emerged as a major economic crisis for traders in Siliguri. “Both traders and farmers of Bengal are being affected. Both the Khuchro Byabshai Samity and Siliguri Fruits and Vegetables Commission Agents have written to the West Bengal government to help resolve this issue. Earlier, it was a near blanket ban. However now, they are allowing potatoes, onion, garlic, chilies, carrot and tomatoes to be taken from Siliguri to Sikkim,” stated Tapan Saha of the regulated market, Siliguri. Around 70 tonne of vegetables used to make their way from the Siliguri market to Sikkim before the ban. The social media too is rife with criticism over the way the confiscated vegetables were disposed of on Wednesday.Many feel that the confiscated vegetables could have been distributed in old-age homes, orphanages and among the poor and needy. If not in Sikkim, they could have been sent back to Bengal. “Throwing food away is like stealing from the poor and hungry. It is a crime,” stated J Chettri, in a social media post.Even the Opposition parties are up in arms against this move in Sikkim. “During a meeting with the Union Home minister Rajnath Singh, I updated him on the imbroglio concerning the organic issue of Sikkim, wherein the Sikkimese people’s right to food and preferences has been snatched away by this draconian law. The Home minister expressed surprise and anguished over such an immature exercise,” claimed Sonam Lama, MLA, Sikkim Krantikari Morcha.The Sikkim National People’s Party has demanded an immediate roll back of the ban. The party has also demanded a thorough inquiry by an independent and impartial agency into the “organic mission”, based on the findings of the CAG as documented in their annual reports, since the inception of the mission.
Kolkata: The newly opened Misti Hub in New Town did brisk business on Saturday and Sunday and people from all across the town had gathered to buy mouth-watering sweets.The parking bay was full and special parking arrangements were made on the service road. Parking is free on the earmarked area for half an hour. The hub is the only of its kind in Bengal where renowned sweetmakers of Kolkata are sharing the same roof with the traditional sweet meat sellers – the sarbhaja of Krishnanagar, langcha of Shatigarh and with mihidana and sitabhog of east Burdwan. The hub is opened from 12 noon to 9 pm. It will help the airport bound passengers to buy the special sweets of Bengal on way back home. Proper signs will be put up on Biswa Bangla Sarani to facilitate the airport bound buyers.The 10 branded shops that have been set up at the hub are KC Das, Bancharam, Gupta Brothers, Balaram Mullick and Radharaman Mullick, Ganguram Sweets, Nalin Chandra Das, Mithai, Sweet Bengal, New Nabakrishna Guin and Hindusthan Sweets (shop no. 10).HIDCO had imposed a condition that those opening shops at the hub must have experience of 25 years or more. A central atrium with glass walls will bring the sunlight inside.The hub is a combination of tradition and modernity. There will be a caretaker on behalf of Housing Infrastructure Development Corporation ( HIDCO) to look after the facilities. The hub has been built on a shop-in-shop concept. There is a potential market of Bengali sweets both in the country and abroad.Meetings had been held between the sweet shop owners and HIDCO officials including its chairman Debashis Sen where the idea was discussed. The sweet meat sellers accepted the proposal and the hub has come up near Eco Park.The New Town Kolkata Development Authority (NKDA) has made special arrangements to issue trade licences to the shop owners.All the shop owners have come up with new variety of sweets including the modern ones. They are manufactured and packaged maintaining quality health.The hub has given opportunity to the residents of New Town and its neighbourhood to buy quality sweets without visiting Kolkata.