Citation: Claim of supersolid helium disproved by original researcher (2012, October 15) retrieved 18 August 2019 from https://phys.org/news/2012-10-supersolid-helium.html Solid objects hold their shape due to a lattice structure made of atoms. Quantum theory suggests that under very cold conditions, quantum effects can cause some of the atoms in a structure to begin to move freely, thereby acting as a frictionless liquid, resulting in a supersolid. Chan and his earlier partner Eunseong Kim believed they had proven the existence of supersolid helium after conducting an experiment that involved cooling helium that had been collected inside of a type of glass known as Vycor. The helium-glass mixture was hung from a chamber that was spun in first one direction, then the other, oscillating back and forth. As the temperature was brought down, the researchers noted that the oscillation rate increased. This, they claimed, was the result of some of the helium atoms inside slipping between the others in the lattice—a clear sign of a supersolid. Three years later, a team led by John Beamish suggested that bulk helium, rather than becoming a supersolid as it was cooled, instead became stiffer, accounting for the increased oscillation rate found by Chan and Kim. Subsequent experiments by other researchers have found actual examples of this phenomenon and have since named it quantum plasticity. Seeking to settle the matter once and for all, Chan and new partner Duk Kim redesigned the original experiment in a way that eliminated the possibility of bulk helium forming in a gap between the chamber and the helium-glass mixture. Doing so resulted in no increase in the rate of oscillation as the chamber was cooled. This result suggests that the increased oscillation rate of the earlier experiment was due to quantum plasticity, not the development of a helium supersolid. This new research doesn’t disprove theories regarding supersolids of course. Rather, it demonstrates that faulty research can sometimes lead to new discoveries such as, in this case, quantum plasticity. Journal information: Physical Review Letters Probable observation of a supersolid helium phase Explore further The original torsional oscillator used by Kim and Chan in 2004. Credit: M. Chan/Penn State © 2012 Phys.org More information: Absence of Supersolidity in Solid Helium in Porous Vycor Glass, Phys. Rev. Lett. 109, 155301 (2012) DOI: 10.1103/PhysRevLett.109.155301AbstractIn 2004, Kim and Chan carried out torsional oscillator measurements of solid helium confined in porous Vycor glass and found an abrupt drop in the resonant period below 200 mK. The period drop was interpreted as probable experimental evidence of nonclassical rotational inertia. This experiment sparked considerable activities in the studies of superfluidity in solid helium. More recent ultrasound and torsional oscillator studies, however, found evidence that shear modulus stiffening is responsible for at least a fraction of the period drop found in bulk solid helium samples. The experimental configuration of Kim and Chan makes it unavoidable to have a small amount of bulk solid inside the torsion cell containing the Vycor disk. We report here the results of a new helium in Vycor experiment with a design that is completely free from any bulk solid shear modulus stiffening effect. We found no measurable period drop that can be attributed to nonclassical rotational inertia.via Physics Focus (Phys.org)—Moses Chan, co-author of a paper published in 2004 describing work that resulted in claims of the discovery of supersolid helium, has now co-authored another paper, published in Physical Review Letters, describing flaws in his original research. He and new colleague Duk Kim redesigned the original experiment: this time, they found no evidence of a supersolid. 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.
Alexandria, the original town plan superimposed on the reconstruction by Mahmoud-Bey (1866) (Courtesy of CEAlex Archives J-Y. Empereur). Journal information: Oxford Journal of Archaeology 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. A photograph of the early 19th century showing the Canopic road, looking west (courtesy C. Pallini). Alexander III, known more commonly as Alexander the Great was King of Macedon, a state that existed in northern ancient Greece. By the age of thirty he had built one of the largest empires of the ancient world, running from Egypt in the west, to the Indus River in the east. At the time of his birth, the city of Alexandria had not yet been built; he founded the city in 331 BC realizing its future importance as a shipping hub. Since that time, the city has become famous as the site of one of the seven wonders of the ancient world; it’s 400 foot lighthouse at the mouth of its harbor and as the home of Cleopatra and the Royal Library of Alexandria.The researchers write that aligning the city with Alexander’s birth date would have been a way to highlight the king’s power. They next plan to study other cities that were part of the ancient king’s empire to see if they can find other solar patterns. (Phys.org)—Giulio Magli and Luisa Ferro with the Politecnico of Milan claim in a paper published in the Oxford Journal of Archaeology that new evidence they’ve uncovered shows that the ancient city of Alexandria in Egypt was built to align with the sun on the date that Alexander the Great was born. Instead of running parallel to the Mediterranean Sea, they say, the city’s main thoroughfare Canopic Road aligns nearly perfectly with the rising sun as it would have appeared July 20, 356 BC by the Julian calendar. Egypt announces find of ancient cat goddess temple © 2012 Phys.org Historians and archeologists have been studying Alexandria in an attempt to locate the Macedonian king’s tomb which is believed to be in the city in a gold casket inside of a glass sarcophagus. This new research, the authors write, may help with that search.Suspecting that Alexandria may have been built around a solar event occurring during Alexander’s lifetime, the researchers used simulation software to plot the rise of the sun for the day he was born. Doing so revealed that it rose less than half of a degree off the route of the city’s main course. They also found that the “King’s Star” Regulus, located in the head of the constellation Leo, rose in a similar alignment.The researchers note that it was a common practice in ancient times to base architectural designs on astronomical events, pointing out that the Great Pyramid at Giza has been found to be aligned along compass points. Explore further More information: THE ASTRONOMICAL ORIENTATION OF THE URBAN PLAN OF ALEXANDRIA, Oxford Journal of Archaeology, DOI: 10.1111/j.1468-0092.2012.00394.x (ArXiv PDF)AbstractAlexander the Great founded Alexandria in 331 BC. An examination of the topography of the city today allows the identification of the essential elements of the original urban system, and shows that the site was chosen mainly for religious and symbolic reasons. In fact, Alexandria was the prototype of a series of Hellenistic towns designed as ‘king’s towns’ that aimed to make explicit the divine power of their founder. We examine the orientation of the orthogonal grid, which was based on a main longitudinal axis, and show that this axis is orientated to the rising sun on the day of Alexander the Great’s birth. At the time of foundation, ‘King’s Star’ Regulus was also rising along the same direction.via DailyMail Citation: Archaeoastronomers claim Alexandria was built to align with Alexander the Great’s birth date (2012, October 17) retrieved 18 August 2019 from https://phys.org/news/2012-10-archaeoastronomers-alexandria-built-align-alexander.html
Citation: Anthropologist offers possible explanation for collapse of ancient city of Teotihuacan (2015, March 17) retrieved 18 August 2019 from https://phys.org/news/2015-03-anthropologist-explanation-collapse-ancient-city.html (Phys.org) —Linda Manzanilla, an anthropologist with Universidad Nacional Autónoma de México has published a paper in Proceedings of the National Academy of Sciences, offering a possible explanation for the collapse of the early central Mexican city of Teotihuacan—she believes it was due to clashes between groups with differing economic interests. The ruins of Teotihuacan can be seen today at a location approximately 30 miles northeast of modern Mexico City, and offer testament to the flourishing metropolis that once was home to approximately 125,000 people, making it the most populous city in the pre-Columbia Americas. The city got its start around 100 BCE, but was completely decimated by the eighth century. Why it collapsed has been a subject of debate among historians and anthropologists for several years. In this new effort, Manzanilla suggests it was not drought or invaders that brought down the great city, but internal strife among its inhabitants.Manzanilla is basing her claims on her examination of parts of the ruins, along with an analysis of human remains and other artifacts that have been found in the area. She suggests that because of volcanic eruptions in the first and fourth centuries, people were forced to move from the southern basin, and wound up in Teotihuacan, which resulted in a mix of ethnicities. Activity markers, nutritional patterns, isotopes and ancient DNA analysis showed that the immigrants (some of whom brought specialized skills along with them) tended to live on the outskirts of the city in different neighborhoods and were given specific jobs by businessmen that helped to bolster the economy. But it also led to rivalries between the neighborhoods. As time passed, she believes that tensions arose between wealthy businessmen, neighborhood leaders and those that were part of the government. The tension was increased, she claims, by the government insisting on retaining control of all natural resources. Eventually, that tension boiled over and the result was an angry mob of people burning down major parts (administration and ritual buildings) of the city and trashing sculptures and other iconic structures, and eventually to total collapse of the city.She reports that thus far, no evidence of a foreign invasion of any type has been found. 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. Decapitated males from Teopancazco, a neighborhood within the ancient Mexican city of Teotihuacan. Credit: Linda Manzanilla Journal information: Proceedings of the National Academy of Sciences Explore further © 2015 Phys.org Mexico archaeologists explore Teotihuacan tunnel (Update) More information: Cooperation and tensions in multiethnic corporate societies using Teotihuacan, Central Mexico, as a case study, Linda R. Manzanilla, PNAS, DOI: 10.1073/pnas.1419881112AbstractIn this paper, I address the case of a corporate society in Central Mexico. After volcanic eruptions triggered population displacements in the southern Basin of Mexico during the first and fourth centuries A.D., Teotihuacan became a multiethnic settlement. Groups from different backgrounds settled primarily on the periphery of the metropolis; nevertheless, around the core, intermediate elites actively fostered the movement of sumptuary goods and the arrival of workers from diverse homelands for a range of specialized tasks. Some of these skilled craftsmen acquired status and perhaps economic power as a result of the dynamic competition among neighborhoods to display the most lavish sumptuary goods, as well as to manufacture specific symbols of identity that distinguished one neighborhood from another, such as elaborate garments and headdresses. Cotton attire worn by the Teotihuacan elite may have been one of the goods that granted economic importance to neighborhood centers such as Teopancazco, a compound that displayed strong ties to the Gulf Coast where cotton cloth was made. The ruling elite controlled raw materials that came from afar whereas the intermediate elite may have been more active in providing other sumptuary goods: pigments, cosmetics, slate, greenstone, travertine, and foreign pottery. The contrast between the corporate organization at the base and top of Teotihuacan society and the exclusionary organization of the neighborhoods headed by the highly competitive intermediate elite introduced tensions that set the stage for Teotihuacan’s collapse.
Citation: New stars discovered in the Rho Ophiuchi Dark Cloud (2016, May 26) retrieved 18 August 2019 from https://phys.org/news/2016-05-stars-rho-ophiuchi-dark-cloud.html More information: arxiv.org/pdf/1605.07365.pdf Rho Ophiuchi Dark Cloud is a dark nebula of gas and dust located some 460 light years away in the constellation of Ophiuchus, making it one of the closest stellar nurseries to our planet. This dense nest of stellar objects is a perfect target for astronomers to search for newborn baby stars.Recently, Pillitteri and his colleagues decided to conduct a detailed X-ray study of this cloud to track down possible newly born stars. They have analyzed the data provided by ESA’s XMM-Newton space observatory, which observed the multiple star system Rho Ophiuchi and its surroundings in August 2013. The spacecraft is able to conduct narrow- and broad-range spectroscopy and to perform simultaneous imaging of objects in both X-ray and optical wavelengths, enabling detailed studies of star-forming regions.Three European photon imaging cameras (EPIC) mounted on XMM-Newton allowed the scientists to detect dozens of X-ray sources, 22 of which turned out to be diskless class III young stars.”We detected 89 X-ray sources (…) Based on infrared and X-ray properties, we can distinguish between young stellar objects belonging to the cloud and background objects. Among the cloud members, we detect three debris disk objects and 22 diskless class III young stars,” the researchers wrote in the paper.According to the study, these stars belong to a small cluster born about five to 10 million years ago during a previous event of star formation just north of a dense core of the cloud, designated L1688. This core itself is believed to contain a stellar population of about 300 young stellar objects. The age of the cluster could be confirmed by the near absence of stars with disks. The scientists try to explain this absence: “We speculate that the densest part cloud was larger in the past and that a fraction of the stars have since migrated away from the cloud. What we observe now is the patchy ‘left-over’ cloud of a process of star formation that did not occur uniformly across the cloud,” the paper reads.The astronomers noted that a proper indication of the age of the stellar objects in Rho Ophiuchi Dark Cloud along with assessment of the ratio of stars without disks to stars still bearing a disk could be crucial to our understanding of star-forming processes in stellar nurseries. They endorse future X-ray observations of multi-core clouds, emphasizing that current motion studies and infrared observations are unsatisfactory for regions distant than 3,000 light years.”Proper motion studies have insufficient sensitivity, photometric selection is strongly contaminated by field stars, and spectroscopic selection requires an enormous effort to study hundreds or thousands of stars – even when using new multi-fiber facilities. Infrared studies are helpful (when crowding is not extreme), but they are sensitive only to stars with circumstellar material, bright in infrared, but insensitive to objects without disks, i.e., class III pre-main-sequence stars,” the scientists wrote. © 2016 Phys.org Star-forming ring spotted around distant supergiant star Kappa Ori Main panel: composite RGB image of WISE images and X-rays. Channel bands: blue = EPIC 0.3-8.0 keV; green = 3.4µm; red = 22 µm. The team indicated the XMM-Newton pointing and the L1688 region which has been extensively studied. ρ Ophiuchi sits at the center of a ring of warm dust that has likely been cleared by its stellar winds. Inset image: composite RGB image of EPIC MOS and PN. Channel bands: red = 0.3-1.0 keV; green = 1.0-3.0 keV; blue = 3.0-8.0 keV. Different colors of the XMM-Newton sources indicate soft (yellow) or hard (blue) X-ray spectra. Image credit: Pillitteri et al., 2016 An international team of astronomers led by Ignazio Pillitteri of the Palermo Astronomical Observatory in Italy has announced the discovery of 22 new young stellar objects in a star-forming region called the Rho Ophiuchi Dark Cloud. The newly detected stars constitute a small cluster formed about five to 10 million years ago. The findings are presented in a research paper published online on May 24 on arXiv.org. 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.
A wildebeest wearing a RVC wildlife tracking collar. The collar electronics on the top side of the collar are balanced by a battery box, seen under the neck. Credit: Professor Alan Wilson 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. Prior observation of the wildebeest in the wild has shown that the large animals migrate across parts of Africa looking for food and water. It is one of the few characteristics of the animals that draws attention. Normally they only make it into nature documentaries when they are eaten by other more photogenic animals. Some wildebeest herds have been found to travel as far as 1,900 kilometers—sometimes attracting tourists as they go. Perhaps just as remarkable, the animals do it during the heat of day, which can soar to over 38 degrees C. And until now, it was believed that the creatures, also known as gnu, needed to stop during such migrations each day to drink water. But the researchers with this new effort found that wildebeests can travel for up to five days without drinking any water at all. Curious as to how they could accomplish this feat, the researchers darted several specimens and took muscle tissue samples for study back in their lab.The researchers found that the muscle tissues were extremely efficient. Administering electric shocks while measuring the amount of heat released showed that approximately 62.6 percent of the energy used by the muscles went into muscle movement—just a third was lost as heat. The researchers point out that such high efficiency has only ever been surpassed by turtles. Most animals have muscles that are far less efficient, with an average of just 25 percent efficiency. A wildebeest wearing a RVC tracking collar. The black globe thermometer and humidity sensor can be seen on the left side. Credit: Professor Alan Wilson The researchers also point out that such high muscle efficiency is why the animals are able to walk so long without drinking—with less heat loss, less water is required for cooling. That means less is given off as evaporation, resulting in less need for drinking.The wildebeest is thus the largest animal to have its muscle efficiency measured directly, and offers a framework for studying other animals in the field as well. Journal information: Nature © 2018 Phys.org More information: Nancy A. Curtin et al. Remarkable muscles, remarkable locomotion in desert-dwelling wildebeest, Nature (2018). DOI: 10.1038/s41586-018-0602-4 Explore further Sarcolipin tricks muscle cells into using more energy, burning fat Citation: Wildebeests’ super-efficient muscles allow them to walk for days without drinking (2018, October 25) retrieved 18 August 2019 from https://phys.org/news/2018-10-wildebeests-super-efficient-muscles-days.html A team of researchers with the University of London, University College London and the University of Botswana has found that the wildebeest has extremely efficient muscles. In their paper published in the journal Nature, the researchers describe their study of the migrating animal and what they found.
Explore further The researchers, Ermioni Papadopoulou and Petros Koumoutsakos at ETH Zürich, Constantine M. Megaridis at the University of Illinois at Chicago, and Jens H. Walther at ETH Zürich and the Technical University of Denmark, have published a paper on the fast-moving water droplets in a recent issue of ACS Nano.”We can get very high-speed directed transport of water droplets on the nanoscale, without expending any energy but simply through the patterning of graphene,” Koumoutsakos told Phys.org. “This may have important applications in nano-fabrication and precise drug delivery. It also provides for the first time a simple quantitative explanation for the ultrafast transport of water at the nanoscale.”This nano-/microscale mode of transport is very different than anything observed on the macroscale. The graphene surface was structurally patterned to create wettability gradients, ranging from hydrophobic to hydrophilic. The water nanodroplets, each consisting of approximately 1500 water molecules, were then placed on the surface. The different surface patterns created large contact angles on the hydrophobic domains and smaller contact angles on the hydrophilic domains. The differences in the contact angles at the advancing and receding ends of the water droplets set the droplets in motion and accelerated them forward.Similar mechanisms are found in nature, such as on the surface of the Namib desert beetle and the vein network of banana leaves. These surfaces have patterns that result in the improved collection and transport of water. In experiments with the graphene, the researchers observed water droplet velocities on the order of 100 meters per second, which is two orders of magnitude faster than the highest velocities reported for water droplets propelled by certain other methods, such as surface energy gradients. As expected, smaller droplets move faster than larger ones due to the larger droplets’ increased inertia and greater friction with the surface.After analyzing the underlying mechanisms for the water transport, the researchers derived a scaling law and developed a model that can be used to predict droplet trajectories. This information can be used to design future devices for potential applications, such as high-efficiency drug delivery, electricity generation, and ultrafast heat dissipation for nano- and microscale systems. The researchers plan to further investigate high-speed water transport mechanisms in places other than graphene.”We are examining ultrafast transport of water in other nanostructures, such as carbon nanotubes,” Koumoutsakos said. More information: Papadopoulou et al. “Ultrafast Propulsion of Water Nanodroplets on Patterned Graphene.” ACS Nano. DOI: 10.1021/acsnano.9b00252 A comparison of velocities of water nanodroplets on patterned graphene, a race car, and a cheetah. Credit: Papadopoulou et al. ©2019 American Chemical Society Are we at the limits of measuring water-repellent surfaces? Journal information: ACS Nano © 2019 Science X Network In a new study, researchers have propelled water nanodroplets across a graphene surface at speeds of up to 250 km (155 miles) per hour—which, for comparison, is about twice as fast as a sprinting cheetah. The water droplets’ ultrafast velocities don’t require any pump, but instead occur simply due to the geometric patterns on the graphene surface, which create different contact angles at the front and back of the moving droplets to propel them forward. Citation: Water nanodroplets zip across graphene faster than a cheetah (2019, May 20) retrieved 18 August 2019 from https://phys.org/news/2019-05-nanodroplets-graphene-faster-cheetah.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.
Read the whole story: The Chronicle of Higher Education The psychologist Todd Kashdan writes, “If you want people to be interested, committed, and willing to devote effort to learning, mastering, and using these skills for the long haul, then you can’t avoid the initial step of stimulating excitement.” In short, if you really want a student like Alex to learn and succeed, something needs to happen first: You need to engage him. Alex can do all of that — but he could use your help. As his instructor, you can stimulate his curiosity with an inspiring and energizing presentation style, with activities and assignments that maximize his sense of control over the material, and with expertise that helps him reach just a bit beyond his current abilities. To have any hope of learning the material, Alex needs to actually involve himself in the course. He needs to direct his attention to the lecture and the problem sets. He must be willing to use his working memory to attempt solutions rather than daydream about his life outside the small windowless room full of equations. He needs to decide the information is important enough to commit to memory and then be motivated to grapple with it later, on his own time, to prepare for the exams. Consider a student in an introductory math class — let’s call him Alex. Alex had some unpleasant experiences with math in high school. When he got to college, he tested into a math course below the level that would count toward his general-education requirements. He is thus feeling wary about the semester, and resents having to “waste” expensive college credit on a course that he is unlikely to enjoy and that won’t get him any closer to his degree.
Theatre is a creative platform to create awareness and challenge minds. An increasing number of people especially in metros are audience to shows that highlight their creative side, believe most theatre connoisseurs.With this belief, the play U-Turn will provide some food for thought. Starring Poonam Dhillon and Asif Sheikh, the story revolves around an uncanny relationship between a man and a woman and their unusual musings.‘U Turn is a melody but not traditional, it is a clash of generation cultures but not an advised propaganda, it is the charter of changes you are facing and you might not be prepared for it. This is a very contemporary and rare play on the life reality,’ said Asif. Also Read – ‘Playing Jojo was emotionally exhausting’The play has a humourous element to the story of two people in love who couldn’t be with each other. They meet accidently meets and their journey starts. Asif is a retired Army officer while Poonam is a housewife from Pune. ‘They take you away with them and leave you at times when you try thinking that the situation resembles with your life. It can quite universal,’ said Poonam.Poonam is back to Delhi theatre stage after long with U Turn. Her earlier plays — Also Read – Leslie doing new comedy special with NetflixPerfect Wife, Perfect Husband and Pyar Mai Kabhi Kabhi were appreciated. ‘Delhi is always a temptation. The play was in Marathi and I heard a lot about it. Being a part of its Hindi version is great,’ added Poonam.She has been away from celluloid since 2009. Is retirement on her mind now? ‘I can never take a complete break from films. I started out when I was quite young and now over more than two decades, I have achieved enough. My work is more of a pleasure for me and I am aiming for a much balanced life now,’ Poonam said.U turn to films then it seems.DETAILAt: Chinmaya Mission, Lodi Road when: Today Timings: 6 pm onwards
He further demanded that the LG should make arrangements for permanent fast track courts for the trial of cases of rape against women in Delhi which should deliver judgments within six months.In a letter written to the L-G, Upadhyay said it has often been seen that there is negligence in the initial medical tests of rape victims due to which the evidence becomes weak. “At least four hospitals in Delhi should be designated for medical test of the rape victims where there should be a panel of lady doctors,” said Upadhyay in the letter. It’s important to mention that setting up of fast track courts was in the election manifesto of all the political parties including BJP, Aam Aadmi Party and the Congress but nothing could materialise due to short lived AAP government followed by the President’s rule. “Besides, ensuring speedy justice in rape cases, the police patrolling must be increased and police reforms be introduced to handle the rape cases properly,” he added, expressing his concern on poor collection of evidences by the police. Also Read – Company director arrested for swindling Rs 345 croreAam Aadmi Party, however, criticised both BJP and the Union Home Minister. “The government and the Home Minister also owe an explanation on what the government has done for women’s security in the past six months. Women’s security was one of the main issues the BJP had picked up during its election campaign,” said AAP spokesperson, alleging the issue was raised by the BJP only to gain political mileage during the elections. The party also blamed the Central government’s insensitivity towards the issue which is imperative from the government’s deciding to discontinue women-only taxi service “Sakha”, which was started after the Nirbhaya incident. Also Read – Man who cheated 20 women on matrimonial websites arrestedNot just that, the government has also scrapped Rs 200 crore One Stop Crisis Centre for women in distress which was conceived after the December 16 case. The Centre was aimed at giving medical, police, legal and emergency services to women in distress. “It’s strange that the government happily allocated Rs 600 crore for security of VIPs but refused to spend Rs 200 crore for women’s security. These two decisions of the government clearly show that the BJP is not serious about the matter,” alleged AAP.
tKolkata: In a major move the Kolkata Municipal Corporation (KMC) on Wednesday pulled down a century-old “dangerous and dilapidated” building in Central Kolkata.The civic authorities had earlier identified the building as dilapidated and requested the residents to vacate the premises. But despite the KMC notice, the residents continued to stay in the house. It had also put up a notice in front of the house.KMC usually does not pull down old structures that are occupied on humanitarian grounds and requests the residents to repair them. But the requests only evoke lukewarm responses. Also Read – Heavy rain hits traffic, flightsThe residents continue to stay in the old houses and KMC is blamed when portions of these houses collapse. In 2017, as many as 22 people who used to live in old dilapidated and dangerous houses, had died.As monsoon poses a serious threat to these structures, the Building department of KMC had decided to demolish these houses. A KMC team led by the senior officials of the Building department and demolition workers began pulling down the old tenanted house on Rani Rashmoni Road. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedThe building, not repaired for the past 50 years or more, was occupied by tenants who pay monthly rent that vary between Rs 25 to Rs 50 per month. The owner said that it is not possible for him to repair the building with this amount.Senior civic officials said around 2,000 buildings have been identified, which are dangerous and dilapidated. The civic authorities have failed to identify the owners of some of these houses. “The problem lies with the houses where the ownership is not known. The tenants had trespassed the houses and are not paying any rent,” they said. On March 10, 2017, the Bengal Legislative Assembly had unanimously passed The Kolkata Municipal Corporation (Amendment) Bill, which gives KMC the power to auction a building, pull it down and construct a new one with proper rehabilitation of the tenants, where the owners have failed to repair the structures.KMC had put up billboards all over the city, requesting the owners of buildings that are more than 50 years old, to examine the health of the structures by an empanelled structural engineer. Senior civic officials said some owners of old buildings have shown interest in pulling down the houses with proper rehabilitation of the tenants.”We cannot allow inmates of old dilapidated buildings to die every year. We will continue to pull down these structures for the safety and security of the occupants of the adjacent buildings,” a senior civic official said.