Researchers use centuries of data to map Earths westward magnetic field drift

first_img Citation: Researchers use centuries of data to map Earth’s westward magnetic field drift (2013, October 10) retrieved 18 August 2019 from https://phys.org/news/2013-10-centuries-earth-westward-magnetic-field.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. Scientists and explorers have known for centuries that the magnetic field that surrounds our planet drifts—ship captains made note of it in their logs as far back as the 1500’s. Research over the years has found that the magnetic field is caused by the movement of liquid iron around a solid core causing the creation of an electric current. They’ve also learned that it’s the magnetic field that protects the planet from charged particles that come streaming in from the sun—without it, life would not exist. Harder to explain is why there is more drift in the lower parts of the Western hemisphere than in the northern parts or in the east. In this new effort, the researchers used data old and new (from ship logs, to scientific observations to satellite data, etc.) to explain, they say, two reasons behind such differences in shift.The first reason is tied to the impact gravity has on the inner core and the mantle—it forces the creation of huge rotating vortexes in the outer mantel known as gyres—which are apparently more concentrated at lower latitudes. Core convection tends to push them westward.The second reason is due to the Earth cooling—as it does so, the outermost part of the liquid outer core cools as well, causing it to harden—but, it does so unevenly. The researchers say that more hardening under Indonesia causes more buoyancy which in turn causes distortions to the gyre leading to a westward shift in the magnetic field.Taken together, the researchers say a model can be built that depicts with reasonable accuracy, the drift that has occurred over the past several hundred years, and may perhaps even be used as a means for predicting future drift. That matters because changes to the magnetic field have an impact on sensitive electronic equipment and also because it would be good to know how long we can expect to be protected from the sun by it. (Phys.org) —A trio of researchers from France and Denmark has combined data obtained over the past several centuries to create a model depicting the westward drift of the Earth’s magnetic field. In so doing as they explain in their paper published in the journal Nature, the team believes it might be possible to predict where the field will drift in the future. New insights solve 300-year-old problem: The dynamics of the Earth’s core More information: Bottom-up control of geomagnetic secular variation by the Earth’s inner core, Nature 502, 219–223 (10 October 2013) DOI: 10.1038/nature12574AbstractTemporal changes in the Earth’s magnetic field, known as geomagnetic secular variation, occur most prominently at low latitudes in the Atlantic hemisphere (that is, from ?90 degrees east to 90 degrees east), whereas in the Pacific hemisphere there is comparatively little activity. This is a consequence of the geographical localization of intense, westward drifting, equatorial magnetic flux patches at the core surface. Despite successes in explaining the morphology of the geomagnetic field, numerical models of the geodynamo have so far failed to account systematically for this striking pattern of geomagnetic secular variation. Here we show that it can be reproduced provided that two mechanisms relying on the inner core are jointly considered. First, gravitational coupling5 aligns the inner core with the mantle, forcing the flow of liquid metal in the outer core into a giant, westward drifting, sheet-like gyre. The resulting shear concentrates azimuthal magnetic flux at low latitudes close to the core–mantle boundary, where it is expelled by core convection and subsequently transported westward. Second, differential inner-core growth7, 8, fastest below Indonesia, causes an asymmetric buoyancy release in the outer core which in turn distorts the gyre, forcing it to become eccentric, in agreement with recent core flow inversions. This bottom-up heterogeneous driving of core convection dominates top-down driving from mantle thermal heterogeneities, and localizes magnetic variations in a longitudinal sector centred beneath the Atlantic, where the eccentric gyre reaches the core surface. To match the observed pattern of geomagnetic secular variation, the solid material forming the inner core must now be in a state of differential growth rather than one of growth and melting induced by convective translation.center_img Journal information: Nature © 2013 Phys.org Internal fluid flow and magnetic structure. Credit: Nature 502, 219–223 (10 October 2013) doi:10.1038/nature12574 Explore furtherlast_img read more

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Weight riddle solved by Stanford bird wing test

first_img © 2015 Tech Xplore Citation: Weight riddle solved by Stanford bird wing test (2015, January 14) retrieved 18 August 2019 from https://phys.org/news/2015-01-weight-riddle-stanford-bird-wing.html Journal information: Journal of the Royal Society Interface Apart from developing an instrument for drones, the Stanford team’s investigation helps solve a riddle, said BBC News on Wednesday, a riddle about flying birds’ weight. Does a container or truck carrying birds change in weight when the birds inside are flying? Or, to say it in the Telegraph’s use of English: “Would a lorry carrying pigeons change weight if they all decided to fly?” One conclusion was reached in an episode of a US television show, said BBC News. A trailer was weighed while birds flew inside it. The answer was that it made no difference to when the birds were still. The Stanford team’s device produced a different answer; “the weight of the container would actually change as the birds flapped their wings,” said the BBC. Lentink, quoted in the Telegraph, said “you need an unpractical number of bird to cancel the fluctuations out.” Looking from wingbeat to wingbeat, he said, one sees a lot of fluctuation.”The weight of a truck containing just a few flying birds will fluctuate in time; only the lift of an incoherent flock of birds could cancel out [this change],” he said in BBC News. Hovering created double the lift during the wings’ downstroke; the birds had no need to lift their weight in the upstroke. The device is described in Journal of the Royal Society Interface. “In vivo recording of aerodynamic force with an aerodynamic force platform: from drones to birds” is by David Lentink, Andreas Haselsteiner and Rivers Ingersoll, from the department of mechanical engineering at Stanford. How they tested: they recorded the tiny forces from a single bird flying inside a specially designed chamber. They trained two Pacific parrotlets to fly from one perch to another and they examined the aerodynamic forces. Looking ahead, the researchers said their work could help fine-tune miniature drones. “Here, we demonstrate a new aerodynamic force platform (AFP) for non-intrusive aerodynamic force measurement in freely flying animals and robots.” The authors explained the AFP as a box, instrumented with load cells, that encloses the object or animal that generates the net unsteady fluid force. They said, “It works based on Newton’s third law applied to a fluid; the unsteady net fluid force needs to be supported by an equal and opposite net force that acts on the control volume boundary.” Explore further Aerodynamic force platform (AFP) working principle. Credit: Journal of the Royal Society Interface, doi: 10.1098/rsif.2014.1283center_img 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. Tiny UAVs and hummingbirds are put to test More information: : Lentink D, Haselsteiner AF, Ingersoll R. In vivo recording of aerodynamic force with an aerodynamic force platform: from drones to birds, Journal of the Royal Society Interface, rsif.royalsocietypublishing.or … tent/12/104/20141283 A new instrument may help to carry out tests to optimize miniature drones, in attempts to assess their flight performance more precisely. A team from Stanford University have shown how flapping wings enable flying animals and biomimetic robots to generate elevated aerodynamic forces. Animals with flapping wings range from insects and bats to birds and the latter have complex wing motions, such that the ways in which they are able to generate aerodynamic force are not fully understood. The team has made headway, via the measurement method they used. Thus far, measurements demonstrating this capability have been based on experiments with tethered robots and animals; indirect force calculations have been based on measured kinematics or airflow during free flight. “Remarkably,” they said, “there exists no method to measure these forces directly during free flight.” Now Prof. David Lentink’s research team have developed a sensitive device that can measure the weight of a bird in flight; the force produced by every wing flap can be measured.last_img read more

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Measurement of first ionization potential of lawrencium reignites debate over periodic table

first_img 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 gray tantalum tube surrounded by two heating elements in the center of the picture is part of the recently developed surface ion source installed in the JAEA-ISOL system in the JAEA tandem accelerator. Credit: Tetsuya K. Sato, JAEA Lawrencium is an element that does not exist in nature, scientists create it in the lab and use it for study, though the process is difficult and the result lasts for only a few seconds. In this new effort, the researchers used a known technique to create the element, then devised a way to measure its first ionization potential—which describes the amount of energy required to cause one atom of it to be turned into an ion by knocking off one of its electrons. It is this measurement that forms the basis of element placement on the periodic table. To make this measurement for lawrencium (named for Ernest Lawrence), the team created some samples by shooting boron atoms at a bit of californium—doing so caused a few atoms of a lawrencium isotope to come into existence. Those atoms were then captured using a cadmium mist iodide and placed on a piece of metal which was then heated to 2,700 kelvin—hot enough to knock electrons off of some of the atoms. After that, all it took was summing the atoms that were ionized and calculating the energy it took to make it happen. Doing so revealed that it took just 4.96 electronvolts to ionize one of the atoms, an unexpectedly small amount, which likely means that lawrencium’s outermost electron is very loosely bound, which means, that placing the element where it has been put on the periodic table up till now, might not work. As it stands now, the periodic table is arranged in columns and blocks which are based on how an atom’s electrons are put together, with different blocks relating to different types of orbital—the shape created by the path of their orbits. Lawrencium, at this time, appears to have a dumb-bell shape. These new findings create conflicting views on where the element should be placed on the table and has reignited debate on the way the table is structured in general. © 2015 Phys.org Journal information: Nature Explore further Citation: Measurement of first ionization potential of lawrencium reignites debate over periodic table (2015, April 9) retrieved 18 August 2019 from https://phys.org/news/2015-04-ionization-potential-lawrencium-reignites-debate.html (Phys.org)—A team of researchers with member affiliations from across the globe has succeeded in conducting a measurement of the first ionization potential of lawrencium. In their paper published in the journal Nature, the team describes how they achieved the feat and what they believe it means for placement on the Periodic Table of Elements. Andreas Türler of the University of Bern offers a News & Views perspective piece on the work done by the team in the same issue. Superheavy chemistry, one atom at a time The ionization energy of heavy lanthanides (black) and actinides (red) with the current result for lawrencium (Lr). The filled circle symbols represent values recorded in experiments, the ring symbols are estimated values. The two values for lawrencium are in excellent agreement, emphasizing the close correspondence between the theoretical expectations and experimental findings. Credit: Tetsuya K. Sato, JAEA More information: Measurement of the first ionization potential of lawrencium, element 103, Nature 520, 209–211 (09 April 2015) DOI: 10.1038/nature14342AbstractThe chemical properties of an element are primarily governed by the configuration of electrons in the valence shell. Relativistic effects influence the electronic structure of heavy elements in the sixth row of the periodic table, and these effects increase dramatically in the seventh row—including the actinides—even affecting ground-state configurations. Atomic s and p1/2 orbitals are stabilized by relativistic effects, whereas p3/2, d and f orbitals are destabilized, so that ground-state configurations of heavy elements may differ from those of lighter elements in the same group. The first ionization potential (IP1) is a measure of the energy required to remove one valence electron from a neutral atom, and is an atomic property that reflects the outermost electronic configuration. Precise and accurate experimental determination of IP1 gives information on the binding energy of valence electrons, and also, therefore, on the degree of relativistic stabilization. However, such measurements are hampered by the difficulty in obtaining the heaviest elements on scales of more than one atom at a time. Here we report that the experimentally obtained IP1 of the heaviest actinide, lawrencium (Lr, atomic number 103), is 4.96 electronvolts. The IP1 of Lr was measured with 256Lr (half-life 27 seconds) using an efficient surface ion-source and a radioisotope detection system coupled to a mass separator. The measured IP1 is in excellent agreement with the value of 4.963(15) electronvolts predicted here by state-of-the-art relativistic calculations. The present work provides a reliable benchmark for theoretical calculations and also opens the way for IP1 measurements of superheavy elements (that is, transactinides) on an atom-at-a-time scale.Press release The periodic table of elements including in the colored block at the bottom the lanthanides (Ln) and actinides (An). The height of each column indicates the relative first ionization potential of the corresponding element. The result obtained for lawrencium (Lr) is shown by the red column. The binding energy of the least bound valence electron in lawrencium is thus weaker than that in all other actinides and all other lanthanides. Credit: Kazuaki Tsukada, JAEAlast_img read more

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IIC to celebrate a decade with the Festival of Arts

first_imgThe festival will be held from 17 to 24 October and will exhibit a range of activities like music, dance, theatre, films, discussions and special cuisine.  The IIC Experience this year has a wide international participation from countries like South Korea, Indonesia, Philippines, Kazakhstan and Brazil. The week-long festival will include a presentation of Soordas, a music drama based on the life of the 15th century poet presented by Shekhar Sen, a Jazz Concert presented by Interplay with Sonia Saigal, a western classical and traditional Korean music with contemporary dance, a concert of Hindustani Classical Vocal by Ustad Iftikhar Husain Khan, a Kuchipudi recital by Jaikishore Mosalikanti, an evening of Traditional Music from Kazakhstan, Carnatic Vocal by Sanjay Subrahmanyan, a samba concert by Pedro Miranda and finally a Gala Night from the Philippines presenting a  Concert of Rondalla Music by Celso Espejo Rondalla.last_img read more

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Whats on Around Town

first_imgThe Street FoodGear up to indulge in delights at Dhaba by Claridges with an exciting Street Food Festival celebrating the tastes of the street. This unique food festival will provide a plethora of traditional dishes like Anda Toast, Vada Pao, Bun Omelette, and many more. Where: Dhaba by Claridges, DLF Place, Saket When: Throughout the month. Time: 3 – 7 pm   Delicious monsoonAs the city sees its first showers and gets some much needed respite from the heat, Diggin is celebrating the season with some chef specials and beverages, the perfect accompaniments required to complete this monsoon romance. While at the restaurant, as one overlooks the bright green flora after the showers or enjoys the pattering on the window panes and more. Where:  Diggin café, Anand Lok Shopping Centre When: Throughout the month Timing: 11 am to 11 pm Also Read – ‘Playing Jojo was emotionally exhausting’Foodie’s festThe season’s new food festival is here! Enjoy scrumptious Spanish feast with wide array of Tapas and Sagria. The patrons can relish delicacies in tapas palate like Gambas al Ajillo,Pollo al Pimenton ,Calamari a la Plancha ,Setas in vinegar , Tortilla Espanola ,Patatas alioli , Benderillas. Sagria’s include Rose Sangria, Kiwi rosemary sangria and much more.When: On till 31 July Where: Lodi – The Garden Restaurant, Lodhi RoadDrink and think Also Read – Leslie doing new comedy special with NetflixCocktails & Dreams Speakeasy is back with their monthly dose of Drink and Think. Join in for the hottest quiz in town! Quiz-masters Sanjay Chugh and Vikram Achanta will be throwing questions on Pop culture which shall cover movies, entertainment, celebrities, and advertising. Participants and winners stand a chance of winning goodies from the bar. So step into for a fun Quiz Night session over delectable cocktails with your friends! When:19 July Where:Cocktails & Dreams Speakeasy,Gurgaon TIME: 6.30 – 8 pmlast_img read more

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Evelyn Sharma walks for Kolkata Designer

first_imgDesigner Jyoti Sachdev Iyer launched her latest collection ‘Audacieux’ at Shaan-e-Pakistan, held in the national Capital. The model-turned actor Evelyn Sharma was the showstopper. The duo supported the cause initiated by Evelyn Sharma’s NGO ‘Seams for Dreams’.Evelyn says, “I am happy to be a part of this noble event that beautifully binds two nations. I really admire the collection. I like the fact that the designs are bold and for today’s woman.”  Also Read – ‘Playing Jojo was emotionally exhausting’‘Audacieux’ is a French word for bold, and the collection comprises of bold and edgy silhouettes. The actor recently launched her NGO ‘Seams for Dreams’ which she expresses as, “the universal love for fashion.” The NGO focuses on getting together fashionistas and their support for humanitarian purposes. This 3 day mega event focused on showcasing the culture and products by renowned Indo-Pak couturiers. This first-of-its-kind showcase aims to bring together talented designers and artisans from both sides of the border.  Also Read – Leslie doing new comedy special with NetflixDesigner Jyoti Sachdev Iyer’s line of designs comprised a range of interesting Indian wear combining western silhouettes with Indian fabrics and embellishments. The fabrics used are georgettes, chanderis, slub chanderi and stretched lycra. The western line comprised drapes in stretch fabrics. “I was anxious and excited to showcase my collection in Delhi for the first time. All my designs have traditional Indian roots and bold cuts. I hope my bold and edgy collection is appreciated.” says talented designer Jyoti Sachdev Iyer.The designs are a beautiful marriage of contemporary inspirations and traditional asthetics.last_img read more

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CBI arrests 2 including IT inspector for taking Rs 10 Lakh bribe

first_imgKolkata: The Central Bureau of Investigation (CBI) has arrested two persons, including an Income Tax inspector, on alleged charges of taking bribe of Rs 10 lakh.Income Tax inspector Dharmsheel Agrawal, who was working in the office of joint commissioner of Income Tax of Range-III in Lucknow, was arrested along with one Samrat Chandra. A case was registered in this connection under various sections of the Prevention of Corruption Act against the Income Tax inspector.It was alleged that the Income Tax inspector had demanded an illegal gratification of Rs 25 lakh for releasing FDRs worth around Rs 7 crore of a Kolkata-based private company. The FDRs were seized by the Income Tax department. The Income Tax inspector had finally agreed to take the money in phases. In the first phase he agreed to take Rs 10 lakh. CBI officers caught him and another person from Lucknow while accepting the money.last_img read more

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Bogie of Dhauli Express derails none injured

first_imgKolkata: A bogie of the Howrah-Puri Dhauli Express derailed near Panskura Station in East Midnapore on Tuesday morning.However, as the train was moving slow, none was injured in the incident that took place between Bhogpur and Panskura stations in the Howrah-Kharagpur section at around 7.10 am, a spokesperson of South Eastern Railway said. According to the official, the wheel of chair car coach B-3, which was the sixth bogie from the engine, derailed, resulting in panic among the passengers who were travelling in it. The matter was immediately informed to the senior officials of South Eastern Railway. Also Read – Rain batters Kolkata, cripples normal lifeAn accident relief train immediately rushed to the spot which is about 67 kilometres away from Howrah, with senior railway officials and engineers. The train resumed its journey towards Puri after the affected bogie was detached from the rake. The bogie was dragged a few metres from the spot where it had derailed. A senior official of South Eastern Railway said that 12703 Howrah-Secundrabad Faluknama Express halted at all stoppages of Dhauli Express up to Khurda Road Station, so that passengers en route do not face any inconvenience. Helpline numbers were made available at various stations including Howrah, Cuttak and Balasore in Odisha. Senior railway officials have started a probe in this regard. They are investigating to know if the bogie derailed due to any technical glitch. The technical management experts of South Eastern Railway also visited the spot.last_img read more

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HC restrains Vijayvargiya over defamatory statements against Abhishek Banerjee

first_imgKolkata: Calcutta High Court has issued an order of injunction restraining Kailash Vijayvargiya, national general secretary of the BJP, asking him to refrain from making defamatory statements against TMC MP Abhishek Banerjee.Vijayvargiya had alleged that Banerjee was responsible for deaths of 12 people due to illicit liquor and was linked to cattle and arms smuggling along with illegal coal extraction. The High Court observed that such defamatory statements by picking out a single individual amounted to disparagement and that Vijayvargiya had failed to provide any justification for such allegations. Also Read – Rain batters Kolkata, cripples normal lifeOn November 28, around 12 people had died after consuming illicit liquor at Chowdhurypara village in Nadia’s Shantipur. After the incident, Vijayvargiya commented that Abhishek was making money from the sale of illicit country liquor and was directly responsible for the death of those 12 persons. Such malicious statements of Vijayvargiya were published in newspapers, news channels and on the Internet. On December 1, the advocates of Abhishek Banerjee issued a cease and desist notice to Vijayvargiya, refraining him from making and circulating defamatory statements against Abhishek and also tender an unconditional apology. However, Vijayvargiya failed to give a reply to the letter. On December 5, Abhishek’s advocates instituted a suit against Vijayvargiya along with an injunction application before the High Court.last_img read more

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A festival for women farmers

first_imgAs “Women of India Organic Festival 2017” culminated after a 15-day run, Dilli Haat in INA became the foremost hub of India’s largest and most varied offerings of organic products.Organized and sponsored by the Union Ministry of Women and Child Development as an annual affair, the “Women of India Organic Festival 2017″ celebrates and promotes women farmers and entrepreneurs from across India. The total sales by the women farmers and entrepreneurs who came from 25 States was over Rs. 1.84 crores. The success of the festival added to the joy of the women farmers from the remotest corners of the country like, Ladakh, Manipur, Sikkim, Puducherry, Fazalka, Jhajhar among others. The participants had the opportunity to travel and stay in Delhi free of cost for the entire duration of the festival while enjoying the experience of selling their wholesome goods to fascinated Delhiites. Also Read – Add new books to your shelf”The Women of India Organic Festival 2017” was inaugurated at Dilli Haat by the Union Minister of Women and Child Development, Maneka Sanjay Gandhi and Minister of State, Dr Virender Kumar. Maneka Sanjay Gandhi in fact set the ball rolling by doing her Diwali gifts shopping from the Organic Festival. Her example was followed by hundreds of people who rushed to Dilli Haat to make their Diwali gifts unique. The festival from October 1-15 had people coming in droves on all days thereby giving immense encouragement to the sincere efforts of all participants. The main aim of the festival was to support and encourage women and women-led groups that promote organic farming, thus supporting their local community’s economy, creating jobs and keeping farmers thriving, in addition of course to spreading proper awareness about the benefits of organic products. Also Read – Over 2 hours screen time daily will make your kids impulsive Damyanti Devi, a farmer from Uttarakhand shared, “We are so happy that the Ministry has given us the opportunity to sell our merchandise in Delhi. We had to procure merchandise twice over as we sold our initial goods in less than a week. This monetary benefit would certainly help in my daughter’s further education.” Thokcham Sonalika Devi, a farmer from Manipur said, “We would like to thank the Ministry of Women and Child Development for organizing the “Women of India Organic Festival” and also giving us the chance to display our Chakhao black rice of Manipur, which was a total novelty for the people of Delhi. We also got many bulk orders for our products and hope to participate in many such festivals organized by the Ministry in the future too.” The participants of “Women of India Organic Festival 2017” also enrolled themselves in Mahila E-Haat, another initiative of the Ministry of Women and Child Development to meet the aspirations and needs of women entrepreneurs. This unique e-platform exponentially strengthens the socio-economic empowerment of women beyond the festival.last_img read more

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