Europa’s salty surface goes well with fries. NASA/JPL/University of Arizona Europa, the fourth-biggest moon orbiting gas giant Jupiter, hides a salty, liquid ocean underneath its icy shell and thus, may harbor the ingredients necessary for life. A new study has found that Europa’s surface is full of sodium chloride — table salt — and concludes the hidden ocean underneath Europa’s ice may be more similar to Earth’s oceans than previously imagined. The study, published Wednesday in Science Advances by researchers at Caltech and NASA’s Jet Propulsion Laboratory, show for the first time how yellow patches on Europa’s surface, first noticed by NASA proves Voyager and Galileo decades ago, actually indicate the presence of sodium chloride. More astonishing is the fact the table salt has been hidden in plain view for years. Scientists just hadn’t been looking for it. “Sodium chloride is a bit like invisible ink on Europa’s surface,” NASA’s Kevin Hand said in a press release. “Before irradiation, you can’t tell it’s there, but after irradiation, the color jumps right out at you.” To make the discovery, the team irradiated plain white table salt in a laboratory that simulated the conditions present on Europa. They found that the white salt turned a shade of yellow — the same shade of yellow spotted by NASA’s Galileo spacecraft on its imaging missions between 1995 and 2003. To confirm, they turned the Hubble Space Telescope to Europa and had it confirm the yellows on the surface were giving off a chemical signal that represented the irradiated table salt. It did.It’s a particularly important finding because of what it can tell us about the subsurface ocean chemistry. If the sodium chloride does originate from within Europa, then the moon’s ocean may resemble Earth’s much more closely. In a far-flung future, it could provide somewhere to mine as a resource or even settle. However, the authors note that they can’t yet say whether the surface table salt definitely represents the compositon of the subsurface ocean.Still, it opens the door for further investigation of Europa and suggests it may even be more geologically active than scientists once thought. If you want to sneak a look at Jupiter and its moons, there’s no better time. Jupiter is so close to the Earth right now that you only need a pair of binoculars. Europa is particularly bright so you shouldn’t have trouble spotting it. Take some popcorn and make a night of it. 3 Share your voice Comments Tags Space geeks tweak NASA images of Jupiter’s red spot 20 Photos Sci-Tech
Two men were killed in separate incidents of lightning strike at Tuardanga and Kadakati villages in Satkhira’s Ashasuni on Tuesday morning, reports UNB.The deceased were identified as Bhajhari Mandol, 50, son of late Mangal Mandol of Tuardanga village and Jahangir Hossain, 34, of Kadakati village of the upazila.Shahidul Islam, officer-in-charge of Ashasuni police station, said a thunderbolt struck Bhajhari around 6:00am while he was going outside for working, leaving him dead on the spot.Meanwhile, another thunderbolt hit Jahangir Hossain while he was fishing in his enclosure, leaving him dead on the spot.Later, locals recovered the bodies, the OC added.
A 55-year-old woman was killed by a covered van which hit her while crossing the road in the capital’s Badda area in front of Fuji Tower on Saturday morning.The deceased, Rizia Begum, 55, is from Gangni of Kushtia. She came to Dhaka to visit her son Abdul Mannan.Leaving her son’s house, Rizia was crossing the road on the way to the bus stop. The van hit her then.The deceased was immediately rushed to the Dhaka Medical College Hospital’s (DMCH) emergency unit. The physicians there declared her dead.Sub-inspector Md Bacchu Miah of DMCH police camp said the body had been sent to the morgue for autopsy.Police seized the van and are looking for the driver to arrest him, added the SI.
“The Dirac monopole is conceptually the simplest model for a magnetic point charge (i.e. a magnetic monopole) and this makes the Dirac monopole important,” Pietilä said. “Monopoles in general can be any point-like defects in a three-component vector field defined in three spatial dimensions, but they are not necessarily associated with a singular filament (the Dirac string).”Through modeling, Pietilä and Möttönen theoretically demonstrate that the Dirac string can be split into two parts by modifying the external magnetic field, which breaks the rotation symmetry of the system. In this case, state-of-the-art experimental methods that measure changes in particle density and spin density could be used to detect a signature of the monopole. In addition, in spin-1 BEC, the spin texture is topologically unstable, allowing it to be removed. Through simulations, the scientists show that removing the monopole could be done by turning off the external magnetic fields. The monopole “unwinds” itself along the Dirac string and leaves behind a closed vortex ring. The speed of the unwinding depends on how quickly or gradually the magnetic field is turned off.The existence of magnetic monopoles has far-reaching implications for many research areas, including the laws of quantum mechanics, theories of elementary particles, and cosmology. Experimentally confirming the existence of monopoles would provide long-sought evidence for some ideas, and possibly open up the doors to other new ones.“The existence of magnetic monopoles implies that the electric charge has to be quantized (that is, it can only appear as an integral multiple of the elementary charge),” Pietilä said. “Existence of magnetic monopoles has also certain cosmological implications. Since monopoles in general are related to the spontaneous symmetry breaking, they impact the unified theories describing the interactions between the elementary particles. In the context of condensed matter physics, monopoles typically arise as a manifestation of some exotic collective behavior of matter and can be used to explain the unusual characteristics of such systems.”More information: Ville Pietilä and Mikko Möttönen. “Creation of Dirac Monopoles in Spinor Bose-Einstein Condensates.” Physical Review Letters 103, 030401 (2009). link.aps.org/doi/10.1103/PhysRevLett.103.030401Copyright 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. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. (PhysOrg.com) — For decades, scientists have been intrigued by the hypothetical existence of magnetic monopoles – particles with only a north or south magnetic pole, thus having a nonzero magnetic charge. But while modern theories predict their existence, monopoles have not yet been experimentally observed, despite numerous attempts. Recently, physicists have introduced a new method to create analogies to magnetic monopoles, and predict that they could be observed with current technology. Possible configurations for the spin texture of a Bose-Einstein condensate. These defects give rise to a vorticity field that is equivalent to the magnetic field of a magnetic monopole. Credit: Pietilä and Möttönen. Explore further Citation: Physicists Propose a Method to Observe Dirac Monopoles (2009, July 28) retrieved 18 August 2019 from https://phys.org/news/2009-07-physicists-method-dirac-monopoles.html Ville Pietilä and Mikko Möttönen, both of the Helsinki University of Technology in Finland and the University of New South Wales in Australia, have published their theoretical demonstration in a recent issue of Physical Review Letters. Here, they explain how applying an external magnetic field to a Bose-Einstein condensate (BEC) – a large group of cold atoms that exhibits coherent quantum properties – can create point-like topological defects on the spin texture of the BEC. These defects give rise to a vorticity field that is essentially equivalent to the magnetic field of a magnetic monopole.“Since all experimental attempts to find magnetic monopoles have proven to be futile, there is no experimental evidence supporting the existence of magnetic monopoles,” Pietilä told PhysOrg.com. “Other types of monopoles without the Dirac string have been realized in experiments already in the early ‘90s in liquid crystals. An analogy of the real space magnetic monopole was reported to occur in the crystal momentum space of a metallic ferromagnet, but the experimental evidence in this case is somewhat indirect. Dirac monopoles in the more general settings are predicted to occur in various systems such as superfluid Helium-3 and dilute spin-1 Bose-Einstein condensate but so far there are no (direct) experimental observations although they may have been present in some of the Helium-3 experiments. There is also a very recent suggestion on how to induce a magnetic monopole to a band insulator.“Since magnetic monopoles have never been observed, it is pertinent to ask whether there is something unphysical in the whole concept,” he continued. “Our work shows that at least the Dirac monopole can be realized experimentally, thus indicating that it is more than just a theoretical curiosity. However, it should be stressed that our work does not tell anything about the existence of magnetic monopoles in the electromagnetic field.”Pietilä and Möttönen predict that it should be possible to design an experiment to detect the monopole in this situation, if it does exist. As they explain, the magnetic field of the monopole is provided by a Dirac string, which is a line extending from the monopole to infinity. The Dirac string explains why the monopole charge comes in discrete quanta. Since the Dirac string carries two quanta of angular momentum, it is expected to be prone to splitting into two separate strings, each carrying a single quantum. Making magnetic monopoles, and other exotica, in the lab
Kolkata: The Calcutta High Court on Friday refused to stay the election for the Mayoral post in Kolkata Municipal Corporation, which will be held on Monday, December 3. KMC chairperson Mala Roy held a meeting with the councillors and urged them to be present for the voting and use their democratic rights. 114 out of 122 elected councillors of Trinamool Congress attended the meeting.It may be mentioned that Firhad Hakim, who holds the post of state Urban Development and Municipal Affairs minister, has been chosen as the Mayor designate by the councillors of Trinamool Congress, following former Mayor Sovan Chatterjee’s resignation from the post. Also Read – Rain batters Kolkata, cripples normal lifeCPI(M) councillor Bilquis Begum had moved the High Court, challenging Hakim’s election on the ground that he was not an elected councillor from any of the wards of the civic body. Justice Debangshu Basak on Friday directed the state and KMC to file affidavits in opposition to the petition of the CPI(M) councillor and said that the matter will be further heard on December 17. The petitioner has challenged the Kolkata Municipal Corporation (Second Amendment) Bill, 2018, which was passed by the state Assembly recently. It has also received the assent of the Governor, which allows a person who is not an elected councillor, to be made a Mayor of KMC. The person, however, would have to be elected within six months, in order to continue in the post. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killed”Some of the councillors could not turn up today (Friday) because of ill health and two of them are presently abroad. But all of them are expected to attend the elections on Monday, which will be held from 1 to 2.30 pm,” said Roy. When asked whether Sovan Chatterjee, who is a councillor of ward 131, will turn up for voting, Roy said: “The message regarding the elections has been passed to all the councillors.” There will be four booths where councillors will be voting. The oath-taking ceremony of the Mayor is also expected to take place on Monday after the announcement of the results. Mina Debi Purohit from BJP will contest against Hakim for the Mayoral post, while Left Front and Congress have announced that they will boycott the voting.