“The one sentence statement of general relativity is that ‘gravity is the curvature of spacetime,’” explains Dr. Sean Carroll, assistant professor of physics at the University of Chicago. “Really, the differences come in understanding what that sentence means.” 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. Carroll says that origin of the theory of general relativity dates to 1905, when scientists, notably including Albert Einstein, realized that space and time are related characteristics of a four-dimensional existence. “When you meet someone for coffee,” says Carroll, “you have to give four numbers of where to meet. Three of them are in space — latitude, longitude, and height above ground — and the fourth is what time to meet.”However, within this new 4-D framework, says Carroll, Einstein could not understand gravity, and how it worked in spacetime. He decided that rather than being a force, like electromagnetism, gravity must be a property: a geometric curvature. Even though we agree that the angles of a triangle add up to 180 degrees, this rule changes when a curve is involved. When that same triangle is put on a sphere, the angles add up to more than 180 degrees. Likewise, when the curvature of spacetime is recognized, the basic rules thought to apply to gravity are changed.Lately, though, general relativity has been looked at closely. Carroll says that while no evidence exists for the overthrow of the theory of general relativity, there are some points where general relativity may not apply. “General relativity is doing really well,” he explains to PhysOrg.com, “but there are two places where it might break down.”These two places, Carroll says, have to do with very short distances and on very large scales. With very short distances, in terms of quantum mechanics, there are problems with gravity and with general relativity. The theory does not apply in the same way as it does with longer spacetime distances. “In classical general relativity, spacetime has a geometry; in quantum gravity, there should be a wave function that tells us what the likelihood is that spacetime has one of various geometries,” Carroll explains. Even though no experiment exists yet that has cracked the theory of quantum gravity, a new test is being developed in Europe to try and work toward just that (read about it on PhysOrg.com: http://www.physorg.com/news12054.html).The other breakdown might occur on large scales. There is still much about the larger scales that remain hypothetical. General relativity is one of those things. “There is still a question of how much curvature is caused by a certain amount of energy and mass,” says Carroll. “Einstein suggested an equation that related energy to the curvature of spacetime, but it may be right in some circumstances and not in others.” He explains that breaking down dark energy and matter is necessary to understand the implications, but that, so far, their existence is only known through their gravity. “That could be a sign that general relativity breaks down at this scale.”Carroll also addresses the case of special relativity. “Special relativity is special because it is a special case of general relativity. General relativity is, well, general, and special relativity is one particular case.”In the case of special relativity, gravity is “turned off.” Carroll explains that gravity can be ignored in this subset because it is such a weak force. “Special relativity deals with the idea that different people moving at different velocities will have different perceptions of what they see, and gravity is not taken into account.” But, he continues, work with particle accelerators show that special relativity is extremely accurate for many experiments.Understanding general relativity is more a function of realizing that gravity is a property of spacetime, and one of its properties is gravity, which is actually a curvature. The effects we see, explains Carroll, comes from the fact that particles cannot move in a straight line. “Particles are trying to move in straight lines,” he says, “but there are no straight lines because spacetime is curved.”By Miranda Marquit, Copyright 2006 PhysOrg.com Citation: Generally Speaking: A Primer on General Relativity (2006, April 13) retrieved 18 August 2019 from https://phys.org/news/2006-04-primer-relativity.html
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Citation: Researchers Demonstrate Quantum Teleportation and Memory in Tandem (2008, January 30) retrieved 18 August 2019 from https://phys.org/news/2008-01-quantum-teleportation-memory-tandem.html Explore further Coupling qubits to sound in a multimode cavity 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. In research that may be a key step toward real-life quantum communication—the transmission of information using atoms, photons, or other quantum objects—researchers created an experiment in which a quantum bit of information is transported across a distance of seven meters and briefly stored in memory. This is the first time that both quantum memory and teleportation, as the information transfer is known, have been demonstrated in a single experiment. The experiment was performed by scientists from the University of Heidelberg in Germany, the University of Science and Technology of China, and the Atomic Institute of the Austrian Universities in Austria. The work was led by Prof. Jian-Wei Pan, a physicist at the University of Heidelberg.A quantum bit, or qubit, is the most basic unit of quantum information. It takes the form of a particular configuration, or “state,” of an atom or photon. Unlike a traditional computer bit, the most basic piece of information a computer can store, qubits represent the superposition of “0” and “1,” rather than either a 0 or 1. Additonally, a qubit cannot be copied in the traditional sense. It can only be transferred, without leaving any trace of the original.Quantum teleportation is the way to transfer an unknown quantum state to a distant location without getting any information about the state in the course of this transfer. When a qubit is teleported across a distance, the process is remarkable in that the sending and receiving qubits are not physically connected in any way, and do not “know” of each other’s existence. But through a quantum phenomenon called entanglement, one qubit is nonetheless able to assume the quantum state of another without physically interacting with it.In the present research, described in the January 20 online edition of Nature Physics, an unknown quantum state of a photonic qubit is transferred into quantum memory via teleportation and is stored by two clusters of rubidium atoms. Each cluster contains approximately one million atoms, collected by a magneto-optical trap. The teleported photonic qubit can be stored in memory and read out up to eight microseconds (millionths of a second) before the state is lost.“Such an interface to map the quantum states of photons onto the quantum states of matter, and to retrieve them without destroying the quantum character of the stored information, is an essential part of future quantum technologies,” said Pan to PhysOrg.com. “It represents an important step towards efficient and scalable connection of quantum networks.”The quantum states carried by the photonic qubits are encoded in the photons’ polarization, or the alignment of the photons’ emitted electric fields. Each rubidium cluster encodes the information as a collective spin state over all of the electrons in the cluster. Like other unchangeable properties like mass and charge, spin, or angular momentum, is an intrinsic characteristic of an electron.First, the research group entangled the polarization state of the photons and the spin state of the atom clusters. This entanglement is then exploited to teleport the unknown state of a single photonic qubit onto an atomic qubit seven meters away. This is done by taking a simultaneous measurement of the entangled photons and the photon to be teleported. Taking that measurement entangles the two photons and projects the second photon’s state onto the atom clusters.This setup does have some serious problems. The quantum memory duration is very short and the probability that the photon will be teleported is low. Therefore, the researchers say that “significant improvements” need to be made before the scheme could be used in practical applications.Citation: Yu-Ao Chen, Shuai Chen, Zhen-Sheng Yuan, Bo Zhao, Chih-Sung Chuu, Jörg Schmiedmayer & Jian-Wei Pan Nature Physics advance online publication, 20 January 2008 (DOI:10.1038/nphys832).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.
Molecular Imaging of Cells Likely with New Take on Atomic Force Microscopy Scanning electron microscope images of a cancerous (left) and normal cell, showing the differences in cell “brush.” Image courtesy Igor Sokolov. (PhysOrg.com) — Scientists know that cancerous cells and normal cells have different physical features, but the details of these differences, and why they occur, are not well understood. In a recent edition of Nature Nanotechnology, researchers report measurements of certain physical differences between the surfaces of normal and cancerous cells, suggesting a new way to characterize cancer cells and a possible route for detection. Explore further The group, composed of researchers from the Nanoengineering and Biotechnology Laboratories Center at Clarkson University, was studying human cervical cells. Led by Igor Sokolov, they focused on the cells’ surface features, including microridges and hair-like microvilii, which, perhaps acting like sensors, are one key way that the cells interact with their environment. Together, these features form a cell’s “brush.”They found that normal cervical cells tend to have a brush layer consisting of a single average length – 2.4 micrometers (millionths of a meter) – while the cancerous cells have mostly two typical lengths – 2.6 and 0.45 micrometers. Additionally, their analysis showed that the long cancer-cell brush is about half as dense as that of the normal-cell brush while the short cancer-cell brush is more than twice as dense.The group made these findings using an atomic force microscope (AFM), a high-resolution device that can resolve details down to a fraction of a nanometer. The AFM works by scanning a surface with a tiny cantilever, a beam supported on one end so that it can move up and down. In an AFM, the beam is tipped with a nanometer-scale curved needle often made of silicon or silicon nitride. When brought near a sample, forces between the needle tip and the surface cause the cantilever to deflect. When the entire surface is scanned, the result is a set of force data that represents a surface map of the sample. By analyzing the forces, researchers can recover the nature and type of surface interactions. In previous studies, scientists treated the surface of a cell as flat. In their work, the Clarkson researchers used various supporting techniques, including electron microscopy and confocal scanning laser microscopy, to show that the cell surface is sufficiently “brushy” to be visible in the AFM data. The researchers processed the forces using a “brush on soft surface” model, the type of model used to study polymer brushes (polymer chains tethered to a surface). Prior to this work, scientists had not looked at cell brush in this way.The AFM method has an edge over other microscopy techniques, such as electron microscopy, because it can work with viable cells, avoiding misrepresentations of the cell structure and saving time on sample preparation.More information: Nature Nanotechnology advance online publication 12 April 2009, DOI:10.1038/nnano.2009.77© 2009 PhysOrg.com Citation: Scientists Measure Differences Between Normal and Cancer Cell Surfaces (2009, May 5) retrieved 18 August 2019 from https://phys.org/news/2009-05-scientists-differences-cancer-cell-surfaces.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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. Big eared townsend bat (Corynorhinus townsendii) Credit: Public Domain Journal information: Science Advances Citation: Models suggest little brown bats more susceptible to fungus than bigger bats (2016, February 1) retrieved 18 August 2019 from https://phys.org/news/2016-02-brown-susceptible-fungus-bigger.html Explore further More information: D. T. S. Hayman et al. Environment, host, and fungal traits predict continental-scale white-nose syndrome in bats, Science Advances (2016). DOI: 10.1126/sciadv.1500831 © 2016 Phys.org (Phys.org)—A team of researchers with members from several institutions in New Zealand and the U.S. has found, via modeling, that little brown bats in North America are likely more susceptible to dying due to a certain fungal infection than bigger brown bats, due to their size and habitat. The team has published their results in the journal Science Advances. Scientists and environmentalists alike have become concerned as the number of little brown bats in North America dying due to a fungal infection known as white-nose syndrome, has climbed into the millions. The fungus attacks the facial skin while the bats are hibernating, causing them to wake from hibernation early—that in turn causes them to die from exposure due to early expenditure of energy reserves. Prior studies have shown that other bats in North America and Europe are not harmed by the fungus and that has led to this newest effort to find out why there is such a stark difference between species.To learn more, the researchers conducted simulations to better understand the conditions that lead to fungal growth and then developed models based on the simulations they ran. Next they built models that mimicked the energy requirements of hibernating bats, taking into account the energy needs for the little brown bats, big brown bats, and also their European cousins, serotine and greater mouse-eared bats. They also noted that white-nose syndrome is relatively new to North America—prior studies have indicated the fungus migrated from Europe.In studying the results offered by all of the models, the researchers found that the energy requirements of hibernating bats varied by species as did metabolic rates, and that both were related to size. They also found that the fungus showed faster growth in areas of high humidity. The team also noted that the little brown bats, besides being smaller than all the others under study, also tended to hibernate in more humid parts of the country.Taken together, the data from the models suggests that it is likely the reason that little brown bats are more susceptible to dying from the fungus is because of their smaller size and because they hibernate in areas where the fungus grows faster. The team also suggests that European bats may have evolved traits that help them fight off the fungus—over their much longer history with the disease. Explaining species differences in bat mortality from white-nose syndrome
What happens when art meets heritage? The Ananya Dance Festival will bring you the answer. One of the most awaited classical dance festivals, it features specially designed group choreographs that light up the majestic Old Fort every year.The five-day classical dance extravaganza is in its 11th year. It is organised by the Department of Art, Culture, Languages of the Government of Delhi and Seher in association with Archaeological Survey of India [ASI], which celebrates its 150 years. Also Read – ‘Playing Jojo was emotionally exhausting’‘Ananya is an attempt to popularise the Indian classical arts among the youth. In this age of reality television, our heritage and culture needs to be repackaged innovatively and preserved amongst the future generations. The festival is one such attempt to showcase Indian classical dances in their purest form so that the traditional arts would reach out to more and more people of all ages and strata of society,’ said Sanjeev Bhargava, Creative Director, Ananya. Also Read – Leslie doing new comedy special with NetflixThe festival will start with an opening Bharatnatyam performance titled ‘Shiva Shakti’ based on Lord Shiva and his consort Parvathi [Shakti].‘Shiva Shakti is a dance centered on energy. It depicts the synergised power mingled with Panch Pota [five elements]. The 50 minute choreographed ballet will be put up by a troupe of 11 artistes,’ explained choreographer Saroja Vaidyanathan.Nearly hundred school children will also get a chance to interact with artistes at the festival. The workshop also aims to extend Ananya’s endeavour of introducing people to the possibilities of making a connection with traditional arts and architecture in their own lives and the potential of continuing to experiment with these in the contemporary era. ‘This time we have also introduced an outreach programme whose objective is two fold. One to foster a vision of taking Indian culture to the students. And the second is to present the creative industry – music, dance, theatre, art and related professions to be encouraged amongst the younger generation as viable alternative career options,’ added Bhargava.DETAILAt: Purana Qila [Old Fort]When: 6 October – 10 October Timings: 7 pm onwards Entry: Free
Even at the age of 65 Carlos Santana can rock and play his uniquely soulful guitar as enigmatically and with as much fervor as he did in Woodstock of 1969. With his tight band comprising of a strong rhythm and horn section, the 10 Grammy winner was a treat for all the rock fans at the F1 Rocks concert at Galgotia University grounds last Sunday. The concert was presented by Vladivar and produced by DNA Networks.The repertoire was a collection of his greatest hits but the fascinating quality Santana has that he can get together a completely new line up of backing musicians that deliver. And deliver they did with powerhouse support. His current touring line-up includes Tony Lindsay on Vocals, Raul Rekow on Congas, Dennis Chambers on Drums, Karl Perrazzo on Percussions, Benjamin Rietveld on Bass and David Mathews on Keyboards. Also Read – ‘Playing Jojo was emotionally exhausting’Although this was Santana’s first outing in India he is no stranger to the country as he has been inspired by Indian spirituality in the past and even temporarily adopted the middle name of ‘Devadip’. In a press conference the previous evening he said that he used music to spread world peace and heal the planet and to come to India was to connect with spiritual principles whose awareness he imbibed in the sixties. He said they do what religion and politicians have failed to do and at the concert too he again reiterated that he brings the message of One Light, One Love and Peace. Also Read – Leslie doing new comedy special with NetflixA high point in the concert was with his wife Cindy Blackman on the drums. She is also an acclaimed jazz and rock drummer having toured with Lenny Kravitz and other jazz greats. She backed Santana playing his ever spiritually uplifting classic ‘Europa’ culminating in a dexterous drum solo. Santana was in his electrifying best in a mesmerizing lead solo in ‘Jingo’. Other memorable compositions rendered were ‘Evil Ways’, ‘Black Magic Woman’, ‘Oye Como Va’, ‘Smooth’ and the ever popular ‘Soul Sacrifice’ which included a medleys of his favourite riffs and even the James Bond Theme! The only composition that failed to inspire initially was ‘Game of Love’ as Tipriti of Soulmate who was invited on stage was not familiar with the song but Santana deserves praise for his magnanimity to encourage her. She however excelled in ‘Smooth’ as well as ‘Make Somebody Happy’ along with vocalist Tony Lindsay who himself is an 11 Grammy winner and has spent 20 years with Santana as a frontman.Soulmate were the opening act and set the mood with their great blues originals with Tipriti and her powerful vocals and Rudy on lead guitar. Rudy also presented his track ‘Moon Flower’ inspired by Santana’s ‘Europa’.
Kolkata: Asansol Durgapur Development Authority (ADDA) is all set to introduce an app to facilitate payment of dues by the residents, right through their android or iOS mobile phone. ADDA will soon be integrating all the offices and shops located on land under it for systematic mopping up of the rent dues. It may be mentioned that a new payment gateway service namely “ADDA online” was launched in July last year, so that residents could pay all sort of taxes online right from their home. In the second phase, ADDA will integrate shops and both government and private offices that are entitled to pay rent to it for being situated on its land. “Most of these businessmen would visit our office once in three months, collect details of payments and then clear the dues. Delayed payments have become a cause of worry. Hence, we have decided to launch an app ensuring on-time payments. They will receive the details of their payment dues by 5th of every month and have to clear off the dues by the end of the month. They will have deposit the amount in an account of a private bank with which we have tied up for this purpose,” Arun Prasad, CEO of ADDA said adding that they are in talks with a couple of nationalised banks too in this regard. Since its inception, ADDA, through its online payment gateway, has earned revenue of Rs 11 crore with more than 3,000 customers being registered. The payment gateway was devised for collection of various fees like development charges, water charges, mortgage fees, transfer fees, ground rent among others. Presently, payment for as many as nineteen fees can be done through this portal. With the integration of shops and offices, ADDA will be earning at least Rs 3 crore more. Also Read – Heavy rain hits traffic, flights”The manual system to pay fees took a lot of time in processing and reflecting in our system. However, through this app-based online mode of payment, it will get processed immediately. Most importantly, residents do not have to take any hassle of traveling all the way to our office for payments,” chairman of ADDA Tapas Banerjee said. The app-based service will be launched in July when ADDA will observe the first anniversary of its online payment system. ADDA covers an extensive area of 1603 square km comprising two municipal corporations and eight development blocks.
Kolkata: The stage is set for pandal-hopping with the pleasant sky and forecast of no further rain. The Pujas in South Kolkata and Southwest Kolkata have lined up a number of innovative themes to attract the revellers.Mudiali Club on S R Das Road has adopted the theme Mayer Aanchal. The blend of dokra with Banglar patachitra and collaboration between various folk and tribal art forms from Bengal will come alive at the pandal. ‘Sankhas’ and ‘polas’ have been used to deck up the pandal. Also Read – Rain batters Kolkata, cripples normal lifeThe Shibmandir Club on Lake Temple Road is following the theme Maatir Taney Mayer Kache Phera. The jungles are getting depleting with rapid urbanisation. However, people should not forget their roots. The new generation settled abroad or outside the state should return to their roots, which is the message being reciprocated through the theme.Naktala Udayan Sangha is delivering the message that moments are fleeting and cannot be captured, through its theme Kal (Time). Meanwhile, the famous Suruchi Sangha is celebrating mother and soil together through their theme. Flowers and earthen pots in various shapes and shades have been used for pandal decoration. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedBhowanipore Swadhin Sangha acknowledges the contribution of the Santhals in the freedom struggle of the country, through its theme of Joy Jitkaur Deban Mena (Say we shall overcome), which is based on a Santhali poem penned by Chief Minister Mamata Banerjee. Hogla leaves, barks of trees, leaves of maize, earthen pots and oil lamps have been used to decorate the pandal. Santhal adivasis will be present in the pandal with their typical musical instruments like dhamsa and madol, for entertaining pandal-hoppers. Badamtala Ashar Sangha at Rashbehari Crossing speaks for equal opportunity and equality for women through its theme Sab Charitra Kalpanik. 66 Palli on Nepal Bhattacharjee Street depicts the slow revival of taant and the turnaround of the weavers thorough their theme Taant: Bengal’s own weave.Tridhara Sammilani near Deshapriya Park is trying to revive the lost traditions of Bengal through the theme Prakriti Ratan e Shajabo Joton e. The aim is to familiarise generation Y with the clay and jute artisans of the state, whose prowess remains unacknowledged in this mechanised world.Chetla Agrani is portraying the emptiness experienced after loss through its theme Bisharjan. A palatial building has been erected for people to understand the futility of existence, along with a pond in front of the idol where visitors will see the reflection of Devi Durga. The pond would serve as a symbol where people can shed their sins.Santoshpur Lake Pally between Sukanta Setu and EM Bypass has the theme Maayer Heshel. The ingredients used in the kitchen to prepare meals have been used to decorate the pandal. Six tonnes of turmeric has been used for the same. Behala Natun Dal appeals to the children through their theme to feel the happiness of nature and break the shackles of the digital world in which they are engrossed.