In Twin Paradox Twist the Accelerated Twin is Older

first_img LSU professor resolves Einstein’s twin paradox 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 scientists then considered a situation where the large body that the twins orbit decreases in mass, while the twins’ orbiting radius stays the same. Under these circumstances, twin B’s orbiting velocity no longer follows Kepler’s laws, and so he experiences an acceleration like twin A. However, the ratio of the twins’ proper times still depends only on their velocities, not on their acceleration. Since the twins’ velocities stay the same, with twin B orbiting at a larger velocity than twin A (who is not moving at all), twin B is still younger.“According to Einstein’s relativity theory, the time measured by moving clocks runs more slowly,” Abramowicz and Bajtlik explained. “If two twins move relative to each other, for each of them the time measured by the other one runs more slowly. There is nothing contradictory or paradoxical about that. Note that, quite similarly, two twins who look at each other from a distance both have the impression that the brother looks smaller. For the twin paradox to occur, they should be brought to the same place. At the reunion the twins will find that they do not differ in size, but they may differ in age. What breaks the symmetry here? The standard answer is the acceleration. However, in many situations in which the absolute motion may be defined, the moving twin is younger, regardless of acceleration.”In the examples so far, the faster twin is younger, regardless of any acceleration. However, if the mass of the large body decreased to zero, the situation becomes the original twin paradox: twin A is not accelerated, and twin B is accelerated. In this special case, twin B is still younger – but not because he is moving faster. As the scientists explain, when the mass of the large body is zero, the explanation for the paradox changes: time dilation here is due to twin B’s acceleration, not his velocity.“The mass causes a non-zero curvature of the spacetime, and curvature gives the spacetime a structure that defines the absolute standard of rest,” the scientists explained. “In Minkowski spacetime there are no such structures, and there is no way to tell who of the twins in moving faster in an absolute way.”This version of the twin paradox is not the first to suggest that the paradox can be explained by a difference in velocity between the twins. As in the current version, previous versions also show that the twin who moves or orbits faster is younger. As the scientists emphasize, this explanation holds true for all situations in which the absolute motion of the twins can be defined in terms of some global properties of spacetime. Possibly, the scientists suggest, the explanation might even be extended to the traditional version of the twin paradox by referring to the sky, although this would require further investigation.More information: Marek A. Abramowicz and Stanislaw Bajtlik. “Adding to the paradox: the accelerated twin is older.” arXiv:0905.2428v1.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: In Twin Paradox Twist, the Accelerated Twin is Older (2009, June 9) retrieved 18 August 2019 from https://phys.org/news/2009-06-twin-paradox-older.html Physicist Marek Abramowicz of Goteborg University in Sweden and astronomer Stanislaw Bajtlik of the Nicolaus Copernicus Astronomical Center in Warszawa, Poland, have proposed the surprising new version of the twin paradox, which at first seems to run contrary to the traditional version. However, the scientists show that the traditional version is actually a specific case of a more general concept.“In the best known version of the twin paradox, the twin who is accelerated is younger,” Abramowicz and Bajtlik told PhysOrg.com. “In the version discussed by us the accelerated twin is older. It is quite surprising. It is almost as to say that ‘the older twin is younger.’”In 1905, Einstein described the ideas behind the twin paradox to demonstrate the effects of time dilation according to special relativity. In 1911, physicist Paul Langevin turned the concept into a concrete story involving two hypothetical twins. Ever since then, scientists have offered various explanations for exactly why this aging paradox occurs, and whether it is even a true paradox at all. As Abramowicz and Bajtlik note in their study, it is often claimed that the twin paradox can be explained by the acceleration of the traveling twin that occurs when he turns around to go back to Earth. Abramowicz and Bajtlik show, however, that it is not the acceleration that causes the age difference in most cases. By presenting a scenario in which the accelerated twin is older at the reunion, the scientists show that the final time difference between the twins often depends only on their velocities as measured with respect to an absolute standard of rest, and not on acceleration.In the new scenario, both twins are in circular orbit at different velocities around a large body, with the velocities measured by observers rotating with zero angular momentum with respect to the sky. Abramowicz and Bajtlik considered what happens when twin A stops moving, and so has a velocity of zero, and therefore a non-zero acceleration. Twin B continues to orbit at a set velocity corresponding to Keplerian free orbit and therefore has zero acceleration. Twin A is the accelerated twin, and twin B is not accelerated. As the scientists calculate, contrary to the classical version of the paradox, twin B is younger. center_img Just when you thought you were beginning to understand the twin paradox (maybe), scientists have found something new to ponder. In the original version of the famous thought experiment on time dilation, one twin stays on Earth while the other twin takes a rocket at nearly light speed into space, and returns to find that he is younger than his twin on Earth. But a new version of the story now shows that the twin who experiences an acceleration can be older than the twin who doesn’t accelerate, under slightly different conditions. Explore further Scientists have found that, when twins are orbiting a massive object, time dilation can cause the accelerated twin to be older if that twin is moving slower than the other twin; in this case, velocity is the deciding factor of age, and the twin with the greater velocity is younger. ©2005 Cetin Bal.last_img read more

Sahara desert project aims to power half the world by 2050

first_imgImage credit: Diginfo TV Citation: Sahara desert project aims to power half the world by 2050 (2010, December 2) retrieved 18 August 2019 from https://phys.org/news/2010-12-sahara-aims-power-world.html The Sahara Solar Breeder Project aims to begin by building a silicon manufacturing plant in the desert to transform silica in the sand into silicon of sufficiently high quality for use in solar panels. Solar power plants will be constructed using the solar panels, and some of the electricity generated will supply the energy needed to build more silicon plants to produce more solar panels, to produce more electricity…Leader of the Japanese team, Hideomi Koinuma from the University of Tokyo, said while no one has tried to use desert sand as a source of high-quality silicon before, it is the obvious choice and will be of high enough quality. 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 Desert power: A solar renaissance (PhysOrg.com) — A joint project by universities in Algeria and Japan is planning to turn the Sahara desert, the largest desert in the world, into a breeding ground for solar power plants that could supply half the world’s electrical energy requirements by 2050. © 2010 PhysOrg.com Sahara Solar Breeder Project. (DigInfo TV) The energy generated by the solar power plants will be distributed as direct current via high-temperature superconductors, a process that Koinuma said will be more efficient than using alternating current. He envisages a large network of supercooled high-voltage direct current grids capable of transporting the expected 100 GW of electricity at least 500 kilometers. Even if the grid needs to be cooled with liquid nitrogen, Koinuma said it could still be cost-competitive. (High-temperature superconductors operate at about -240°C.)The Sahara Solar Breeder Project (dubbed the Super Apollo Project by Koinuma) is being developed as part of the International Research Project on Global Issues by the Japan Science and Technology Agency (JST) and Japan International Cooperation Agency (JICA). The team expects to have to overcome many problems, including frequent sandstorms, the need to use liquid nitrogen to cool cables and to bury them in the sand to minimize fluctuations in temperature, and so on. The initial aims of the research will be focused on tackling the expected challenges and demonstrating the project’s viability. Training engineers and scientists from Africa in the entire research and development process is also a goal of the project.Another project aiming to harness solar power in the Sahara was launched last year. The Desertec Foundation aims to supply 15 percent of Europe’s electricity requirements by 2050 using high-voltage direct current transmission lines without superconductors.last_img read more

Chicago choir enthralls Capital audience

first_imgEmmy Award winning choir Chicago Children enthralled audiences by singing the national anthem Jana Gana Mana at the India Islamic Cultural Centre here.The award winning group’s India tour will continue till 3 February. The multi-racial choir performed songs in various languages from their diverse repertoire spanning classical, world gospel and popular music under the direction of president and artistic director Josphine Lee.While 45 children from diverse groups of the US kick-started with the national anthem, chorus of Jaya He reverberated throughout the auditorium Saturday. Also Read – ‘Playing Jojo was emotionally exhausting’United States Ambassador Nancy Jo Powell was also present at the event. The choir, which comprises children of ages between 12 and 18 also performing at Jaipur Literary Festival.Founded during the height of the Civil Rights Movement as a way to unite children from different backgrounds, Chicago Children’s is a non-profit organisation committed to providing multicultural choral music education.It is serving 3,000 children annually through choirs in 51 public schools.last_img read more

Join these pricks for dinner

first_imgThese guys add a wicked twist to your dinner time. Meet Humour Me, a repertoire that is all set to get you laughing as you tuck in. We spoke to director and actor Dhruv Sachdeva – the man behind Dinner with Pricks. Here’s an insight…Where did the concept of Dinner with Pricks come from?Dinner for Pricks is an absolutely original concept that I came up with early last year. It is an original script that I have written & directed. The musical content of the show has also been written and composed by me. No other entertainment company or performance-based group has ever done something like this. It is Humour Me’s first big showcase of the different kinds of entertainment we seek to offer to our audiences. We have all either experienced or heard of ‘supper theatre’ as a concept, but this is nothing like ‘supper theatre’. Here the audiences get to experience a fictional world and dine at a fantasy restaurant which only pops up for a few hours! Also Read – ‘Playing Jojo was emotionally exhausting’Humour Me is an entertainment brand that aims to change the way live entertainment is perceived by people. We don’t believe entertainment is confined to an auditorium or a particular performance space. Humour Me tries to provide the most fantastical entertainment in the most unconventional spaces when you least expect it!For example- Imagine you are a working professional at a bank, and it’s just another mundane Monday, when all of a sudden the lights go out! A bunch of armed masked men storm into the bank, threatening to take the people hostage! Suddenly the entire space is magnificently light up with a burst of colours, and dancers appear out of no where. You are suddenly in a 20-minute musical performance of actors singing and dancing. Your very mundane Monday has turned into an adventure like none other! This is no flash mob. This is your lucky day, and Broadway has decided to come to your door step and entertain you! Also Read – Leslie doing new comedy special with NetflixThe novelty of the concept for me lies in the fact that one does not expect to be dining at a fictional restaurant, and be transported to a different time, setting, whilst the entertainment is not confined to raising of the curtain, or sitting in an auditorium waiting for the show to begin and in turn be entertained. This breaks the conventional approach to entertainment, here the audiences, get the chance to be a part of an experience. Every Humour Me production aims to be different. Expect the unexpected with every Humour Me production. Tell us a bit about the concept.This is the first original musical production in the country, and an experience like none other. We create a fancy French pop-up restaurant from scratch by the name of ‘Le Cigare Volant’ (The flying cigar) purely for the purpose of this showcase. Guests make reservations at a fictional restaurant, where they are greeted by a fantastical service of waiters (actors) & other odd ball characters. To their surprise they are in a full blown musical situational comedy, where the entertainment is the scandalous jabber from the next tables! Dinner For Pricks- is a social statement on the elite of Delhi, and a satire in musical form. How was the cast brought together? Most of the actors in this production are people I have worked with in the past. Over the years I have developed a network of actors & professionals whom I respect and trust in a professional sense. However, because the demands of the creative product are specific, the casting was based on script and the specific needs of the character. This is also a musical production where actors need to be able to sing and dance as well, hence there is only small niche of performers, who have studied this discipline that one can turn to. Have you guys performed this before or is Delhi the first stop?’Dinner for Pricks’ was performed last year, on the 29 July, 2012, and Le Ciagare Volant popped up at the Park Hotel, in New Delhi. There were two shows that played to packed audiences. However, this time around the creative product (script, music, characters & decor) and experience is entirely different. We want our guests to experience something entirely new, each time they visit the fantastical Le Cigare Volant.  If you have performed it earlier what sort of reactions did you guys get?The show got an absolutely overwhelming response from it’s audiences last year. Despite having played out to an audience that is well exposed, and has probably experienced the best of what ‘live entertainment’ has to offer from around the world, the show was thoroughly appreciated! Delhi hadn’t seen original live and musical content  showcased in such a unique way. The talk and buzz from the last show still hasn’t died down, and we were absolutely thrilled. How do you expect Delhi to react to a concept like this?Delhi has suddenly seen a burst of enthusiasm from various spaces on the cultural front. It is almost as if the city has come alive in the last year or so. People from across the city have become more & more receptive to live entertainment as a medium of entertainment. The people of Delhi are thirsty for intelligent entertainment and creative offerings! Thus, Delhi audiences are very receptive to new concepts. The people of Delhi love exclusivity! A show like ‘Dinner for Pricks’ really plays to that exclusivity factor as well, where one can only make reservations for this fantastical journey once in 6 months.From an entertainment perspective, I believe the Indian theatre and live performance space lacks original intellectual properties and content. Our biggest weakness is the lack of original content with some value. We are still far away from being a structured industry where original content can hold value. There is a definite need to start developing original productions.That is where Humour Me is different. We write our own scripts, music, and have content that is our own Intellectual Property. What next for Dinner for Pricks?’Dinner for Pricks’ is a creative property that we aim to bring to the city, and to other metropolitan cities in the country year on year. We want to make ‘Le Cigare Volant’ that fantastical place that people wait for months to dine in and experience.last_img read more

Of love in times bygone

first_imgThe love story between a courtesan and a revolutionary young man was the subject of Janhaar, the play written by eminent writer and theater personality Qudsia Zaidi, performed at the Sri Ram Centre on the fourth day of the 26th Urdu Drama Festival. The six-day festival is being presented by the Delhi government’s Department of Art, Culture & Languages in association with Urdu Academy.Narrated in a unique style, with colours of humour, wit and dance, the play tracks the story of Tawaef Zareena, a beautiful dancer in the times of Nawaabs and Zamindars, who has charmed many a heart with her beauty and sensual art. The story revolves around how different men try to win her heart and outdo each other. The special focus is on the love of Javed, a maverick young man. Presented by Living Opera Theatre, the play was directed by Sheikh Khairuddin.The six-day festival being presented by Delhi Government’s Department of Art, Culture & Languages in association with the Urdu Academy is paying tribute to Abbas and Qudsia Zaidi, the pioneer of Hindustani theater. On the fifth day of the festival, Qudsia’s play Khalid ki Khala, directed by Chander Shekhar Sharma, was performed by the Mask Players Art Group. The festival will end on Saturday with Qudsia’s play Dhoban ko Kapre Diye, directed by Danish Iqbal and presented by the Social Pride Welfare Society.When: On till 18 October Where: Sri Ram Centrelast_img read more

CM should to be trusted to decide JK interest Omar

first_imgFormer Jammu and Kashmir Chief Minister Omar Abdullah on Monday said the chief minister of a state should be trusted to decide what is in the interest of his state, otherwise it was better to “dispense” the state governments and rule from the Centre directly. He, however, said that that the decision to release separatist leader Masrat Alam was J&K Chief Minister Mufti Mohammad Sayeed’s ploy to ensure that the discourse was about anything but the BJP-PDP alliance. “God knows I hold no brief for Mufti Sayeed but a CM has to be trusted to decide what is & isn’t in the interest of his/her state.last_img

Forest dept to introduce recruitment board local youths to be employed

first_imgKolkata: The state Forest department has decided to set up its own recruitment board wherein local youths would be recruited as forest security guards, state Chief Minister Mamata Banerjee said in the state Assembly on Thursday.”These youths possess knowledge of the area, so they will be able to handle forest related problems in an effective manner than the forest guards, who are recruited through Staff Selection Commission (SSC) examination,” Banerjee said in reply to a question from a Left Front MLA, who wanted to know the steps taken by the state Forest department to curb illegal cutting down of trees in forests. Also Read – Rain batters Kolkata, cripples normal lifeShe reiterated that strong action is being taken against this unfair practice and directed Forest minister Binay Krishna Barman to take up the issue seriously. Taking the cue from the Chief Minister, Barman said the state government has decided to set up Forest Recruitment Board for recruiting forest guards.”We have recently recruited 259 forest guards through SSC. These people after joining their jobs in the forests of North Bengal or the Sunderbans have expressed their reluctance in carrying out their duties and prayed for shifting to other places, where forest cover is much less like Kolkata and Howrah. Recruiting local youths will help address this issue,” the minister said. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedThe minister maintained that the department will recruit ‘Aranya Bandhus’ (friends of the forest) in every Gram Panchayat in non-forest areas. “As per rule, a person has to seek permission of the Forest department before felling a tree in a non-forest area. The person needs to approach the range officer who, then seeks the nod of the Divisional Forest Officer (DFO) and, provides the necessary permission to the person. The process is alengthy affair. The ‘Aranya Bandhus’ will now assist the owner to fast track the process of permission,” Barman added. Local youths will be employed as ‘Aranya Bandhus’ and their income will range from Rs 10,000 to Rs 15,000. “We will also offer training to these people for setting up nursery that will act as an added source of income for them. Some of the trees that they grow in the nursery will be taken by the state for plantation and the rest they will be able to sell on their own,” Barman said.last_img read more

Arms and ammunition seized in Kalyani

first_imgKrishnagar (WB): Several arms and ammunition were recovered from a house during a raid at Atghara in Nadia district, the police said. Acting on an information, police raided the area under Kalyani police station and recovered two firearms and 36 cartridges of various weapons from the house of one Arun Mondal on Monday, Superintendent of Police Nadia Rupesh Kumar said. Mondal was arrested.last_img

How marijuana use leads to severe mental disorder

first_imgCannabis or marijuana use increases neural noise in the brain, leading to a severe mental disorder in which thought and emotions are so impaired that contact is lost with external reality, says an Indian-origin researcher.The team from Yale University found that a primary active constituent of cannabis induces transient psychosis-like effects in healthy participants similar to those observed in schizophrenia.“At doses roughly equivalent to half or a single joint, the compound called ‘?9-THC’ produced psychosis-like effects and increased neural noise in humans,” explained senior author Dr Deepak Cyril D’Souza, professor of psychiatry. Also Read – ‘Playing Jojo was emotionally exhausting’The findings suggest that increased neural noise may play a role in the psychosis-like effects of cannabis. The investigators studied the effects of “?9-THC” on electrical brain activity in 24 human subjects who participated in a three-day study. If confirmed, the link between neural noise and psychosis could shed light on the biology of some of the symptoms associated with schizophrenia.“This interesting study suggests a commonality between the effects on the brain of the major active ingredient in marijuana and symptoms of schizophrenia,” stated Dr John Krystal, editor of the journal Biological Psychiatry that published the paper.last_img read more

Six artists one platform

first_imgWhen artists come together under one roof with different artworks for display, there is no place better than Lalit Kala Akademi, for art lovers. ‘Sadanga’, a group show by six contemporary artists from Kolkata, was inaugurated on Monday, February 29 at Lalit Kala Akademi, in the presence of art promoter, Manjula Singh, eminent artist Amitava Das and curator Ved Prakash Bhardwaj.The exhibition will continue till March 6. It seems that ‘bissextus’ (February 29, the extra added day in the Julian calendar every four years) was chosen especially to make the event memorable. Also Read – ‘Playing Jojo was emotionally exhausting’The show contains works of Jayosmita De, Mrityunjoy Chatterjee, Nilima Goel, Pratibha Sarkar, Samir K Dutta and Sarbani Sarkar, who work at the Lalit Kala Akademi in Kolkata. All artists, painters, print maker and sculptor represent new wave of art. They have been exploring different shades of life in metro cities, with the theme of cultural and social changes being the main focus in their creation. The one common thing is their deep concern about society even when they have separate medium of work.The artworks on display are a mix of different themes and forms, from paper mache works, to bronze sculptures to colourful paintings, all depicting meaningful connotations individually. Some of the most striking works are, ‘The king can do no wrong’ a wood work by Jayosmita De, ‘Travelogue’ by Mrityunjoy Chatterjee which is a work of pen and ink and ‘Pitcher’, a paper mache work by Nilima Goel.last_img read more