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
A handout picture provided by the Iranian presidency on 8 May 2018 shows president Hassan Rouhani giving a speech on Iranian TV in Tehran. Photo: AFPUS president Donald Trump is not fit for his job, the speaker of Iran’s parliament said on Wednesday following his decision to back out of the international nuclear pact on Iran.Trump pulled the United States out of the deal on Tuesday, raising the risk of conflict in the Middle East, upsetting European allies and casting uncertainty over global oil supplies.“Trump does not have the mental capacity to deal with issues,” parliament speaker Ali Larijani told the assembly, broadcast live on state TV.Members of parliament burned a US flag and a symbolic copy of the Iran deal, known officially as the Joint Comprehensive Plan of Action (JCPOA), as a session of parliament began. They also chanted “Death to America”.“Trump’s abandoning of the nuclear deal was a diplomatic show…Iran has no obligation to honour its commitments under the current situation,” Larijani said. “It is obvious that Trump only understands the language of force.”General Mohammad Baqeri, the chief of staff of Iran’s military, said Iran had not had to sign the deal.“But that arrogant country (America) did not even stand by its signature,” the Islamic Republic News Agency (IRNA) quoted him as saying.President Hassan Rouhani said on Tuesday Iran would remain committed to the deal without Washington despite Trump’s decision to withdraw from it. The pact was designed to deny Tehran the ability to build nuclear weapons.“If we achieve the deal’s goals in cooperation with other members of the deal, it will remain in place. … By exiting the deal, America has officially undermined its commitment to an international treaty,” Rouhani said in a televised speech.“I have ordered the foreign ministry to negotiate with the European countries, China and Russia in coming weeks. If at the end of this short period we conclude that we can fully benefit from the JCPOA with the cooperation of all countries, the deal would remain,” he said.French foreign minister Jean-Yves Le Drian said the deal with Iran was “not dead” and added that president Emmanuel Macron would speak later in the day to Rouhani.Le Drian said Macron’s contact with Rouhani would be followed by meetings next week, probably on Monday, involving the Iranians and European counterparts from France, Britain and Germany.Trump’s decision drew fierce criticism from Iranian officials and could give hardliners long opposed to the deal a greater edge over Rouhani.“The biggest damage of the Iran deal was legitimising and sitting at the negotiating table with America,” Iran’s army chief Seyed Abdul Rahim Moussavi said, according to the Iranian Students’ News Agency (ISNA).Moussavi said America’s withdrawal from the Iran deal should also be a lesson to Saudi Arabia which was drawing closer to the United States, ISNA reported.Shi’ite Muslim Iran has been locked in a regional power struggle with Sunni Muslim Saudi Arabia that has spilled into the wars in Syria and Yemen, where they have backed opposing sides, and fuelled political rivalries in Iraq and Lebanon.The United States’ Gulf Arab allies, who see Iran as a major security threat, expressed strong support for Trump.Under the deal, struck between Iran, the United States, Russia, China, Britain and France and Germany, Tehran curbed its nuclear programme in return for them lifting sanctions.‘SHENANIGANS’Trump’s decision sets the stage for a resurgence of political infighting within Iran’s complex power structure, Iranian officials told Reuters. It could tip the balance of power in favour of hardliners looking to constrain Rouhani’s ability to open up to the West.“They will blame Rouhani. They will continue their shenanigans at home and abroad. And they will have the US to blame for the failure of the economy,” said Abbas Milani, director of the Iranian Studies programme at Stanford University.Rouhani tried to assure ordinary Iranians, frustrated by high unemployment and stagnant living standards, that Trump’s decision would have no impact on Iran’s oil-reliant economy.“Our heroic people will not be affected by this psychological attack…Iran’s economic progress will continue. Our people should not be worried at all,” he said.Iran’s ruling elite fears a revival of anti-government protests in January that revealed the establishment was vulnerable to popular anger fuelled by economic hardship. At least 21 people were killed in the protests.TOUGH STATEMENTTrump said he would reimpose economic sanctions on Tehran immediately. His decision puts pressure on his European allies, which are reluctant to join the United States in reimposing sanctions on Iran.The US Treasury said the United States would reimpose a wide array of Iran-related sanctions after the expiry of 90- and 180-day wind-down periods, including sanctions aimed at Iran’s oil sector and transactions with its central bank.Iran’s supreme leader, Ayatollah Ali Khamenei, whose hostility towards Washington is the glue that holds together Iran’s faction-ridden leadership, had said Iran would “shred” the deal if the United States pulled out.Rouhani said Iran was ready to resume its curbed nuclear activities if Iran’s interests were not guaranteed under a deal without the United States.Under the 2015 deal, Iran stopped producing 20 per cent enriched uranium and gave up the majority of its stockpile in return for most international sanctions on it being lifted.
The company also brought Apple Music to Amazon’s Echo speakers late last year, and earlier this year announced partnerships with a number of TV manufacturers to bring iTunes to smart TVs.Ironically, Apple hasn’t been as forthcoming about its own speakers. The Homepod, which first launched a year ago, still doesn’t support any third-party music services. Popular on Variety Apple’s music service is apparently heading to Google Home speakers: Apple Music has appeared as a supported service in Google’s Home app for iPhones, Macrumors was first to report Monday night.The service can’t currently be activated on Google Home speakers, but the appearance of the listing suggests that this could change any day. An Apple spokesperson didn’t immediately respond to a request for comment; a Google spokesperson sent the following statement via email:“Apple Music is currently only available for Google Assistant users on mobile phones. We have nothing to announce regarding updates to Google Home.”Apple used to be fairly protective of its own services, reserving them for users of its own devices. This changed with Apple Music, which has been available on Android ever since late 2015, a few months after the service launched on iPhones. ×Actors Reveal Their Favorite Disney PrincessesSeveral actors, like Daisy Ridley, Awkwafina, Jeff Goldblum and Gina Rodriguez, reveal their favorite Disney princesses. Rapunzel, Mulan, Ariel,Tiana, Sleeping Beauty and Jasmine all got some love from the Disney stars.More VideosVolume 0%Press shift question mark to access a list of keyboard shortcutsKeyboard Shortcutsplay/pauseincrease volumedecrease volumeseek forwardsseek backwardstoggle captionstoggle fullscreenmute/unmuteseek to %SPACE↑↓→←cfm0-9Next UpJennifer Lopez Shares How She Became a Mogul04:350.5x1x1.25×1.5x2xLive00:0002:1502:15
“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