After four weeks, the researchers noticed that the tomato plants that had been treated with carbon nanotubes had two times the biomass and two times the height of their non-treated counterparts. The current theory is that the nanotubes penetrate the seed coat of the tomato seeds, allowing water to more rapidly penetrate the seeds and boost their development. Interestingly, the root systems were similar in all of the plants, so the nanotubes did not change the way the roots established themselves. Another issue is that the nanotubes seem to be causing abnormally long internodes, and that might affect the ultimate outcome regarding the viability of mature plants. Additionally, carbon nanotubes as fertilizer might present hazards when used for food plants, since they were found to trigger some toxic effects in mice.In the end, though, it appears that carbon nanotubes may be more versatile than originally imagined.More information: The research has been published in ACS Nano: Carbon Nanotubes Are Able To Penetrate Plant Seed Coat and Dramatically Affect Seed Germination and Plant Growth, DOI: 10.1021/nn900887m© 2009 PhysOrg.com Image: ACS Nano, DOI: 10.1021/nn900887m Silicon nanotubes for hydrogen storage in fuel cell vehicles 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. According to New Scientist, Mariya Khodakovskaya, a plant biologist, and Alexandru Biris, a nanotechnologist, used carbon nanotubes to encourage germination of tomato plants. Tomato seeds were planted, some with a growth medium containing carbon nanotubes, and some without nanotubes in the growth medium. It took only three days for more than 30% of the nanotube tomato seeds to begin sprouting. In that time, none of the non-treated seeds had even germinated.In fact, it took 12 days for 32% of the tomato seeds without nanotube help to germinate. Citation: Can Nanotubes Help Your Garden Grow? (2009, October 6) retrieved 18 August 2019 from https://phys.org/news/2009-10-nanotubes-garden.html (PhysOrg.com) — When we think of nanotubes, we often think of solar panels and physical science. However, it appears that nanotubes can also provide valuable help to plants as a fertilizer. Just add carbon nanotubes, say researchers at the University of Arkansas in Little Rock, and you can get plants that grow faster and bigger than their counterparts. Image credit: Jack Dykinga. These are tomatoes grown with the ACC synthase gene.
Explore further More information: Stuart Licht, Baohui Wang, Susanta Ghosh, Hina Ayub, Dianlu Jiang, and Jason Ganley.” J. Phys. Chem. Lett. 2010. 11 2363-2368. DOI:10.1021/jz100829s Copyright 2010 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. Citation: Solar-powered process could decrease carbon dioxide to pre-industrial levels in 10 years (2010, July 22) retrieved 18 August 2019 from https://phys.org/news/2010-07-solar-powered-decrease-carbon-dioxide-pre-industrial.html The new process, called Solar Thermal Electrochemical Photo (STEP) carbon capture, was recently suggested theoretically by a team of scientists from George Washington University and Howard University, both in Washington, DC. Now, in a paper just published in The Journal of Physical Chemistry Letters, the scientists have experimentally demonstrated the STEP process for the first time.“The significance of the study is twofold,” Stuart Licht, a chemistry professor at George Washington University, told PhysOrg.com. “Carbon dioxide, a non-reactive and normally difficult-to-remove compound, can be easily captured with solar energy using our new low-energy, lithium carbonate electrolysis STEP process, and with scale-up, sufficient resources exist for STEP to decrease carbon dioxide levels in the atmosphere to pre-industrial levels within 10 years.”As the scientists explain, the process uses visible sunlight to power an electrolysis cell for splitting carbon dioxide, and also uses solar thermal energy to heat the cell in order to decrease the energy required for this conversion process. The electrolysis cell splits carbon dioxide into either solid carbon (when the reaction occurs at temperatures between 750°C and 850°C) or carbon monoxide (when the reaction occurs at temperatures above 950°C). These kinds of temperatures are much higher than those typically used for carbon-splitting electrolysis reactions (e.g., 25°C), but the advantage of reactions at higher temperatures is that they require less energy to power the reaction than at lower temperatures. The STEP process is the first and only method that incorporates both visible and thermal energy from the sun for carbon capture. Radiation from the full solar spectrum – including heat – is not usually considered an advantage in solar technologies due to heat’s damage to photovoltaics. Even in the best solar cells, a large part of sunlight is discarded as intrinsically insufficient to drive solar cells as it is sub-bandgap, and so it is lost as waste heat. By showing how to take advantage of both the sun’s heat and light for capturing and splitting carbon dioxide, the STEP process is fundamentally capable of converting more solar energy than either photovoltaic or solar thermal processes alone. The experiments in this study showed that the technique could capture carbon dioxide and convert it into carbon with a solar efficiency from 34% to 50%, depending on the thermal component. While carbon could be stored, the production of carbon monoxide could later be used to synthesize jet, kerosene, and diesel fuels, with the help of hydrogen generated by STEP water splitting.“We are exploring the STEP generation of synthetic jet fuel and synthetic diesel,” Licht said, “and in addition to carbon capture, we are developing STEP processes to generate the staples predicted in our original theory, such as a variety of metals and bleach.”• Learn about becoming PhysOrg.com sponsor and ads-free website Team to chemically transform carbon dioxide into carbon-neutral liquid fuels In the Solar Thermal Electrochemical Photo (STEP) carbon capture process, the sun’s visible light and heat are used to capture large amounts of carbon dioxide from the atmosphere and convert it to solid carbon for storage or carbon monoxide for fuel generation. Image copyright: Stuart Licht, et al. ©2010 American Chemical Society. (PhysOrg.com) — By using the sun’s visible light and heat to power an electrolysis cell that captures and converts carbon dioxide from the air, a new technique could impressively clean the atmosphere and produce fuel feedstock at the same time. The key advantage of the new solar carbon capture process is that it simultaneously uses the solar visible and solar thermal components, whereas the latter is usually regarded as detrimental due to the degradation that heat causes to photovoltaic materials. However, the new method uses the sun’s heat to convert more solar energy into carbon than either photovoltaic or solar thermal processes alone. 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.
SkyNET drone prototype. Diagrams showing the PAAE (pilot, attack, attack, enlist) procedure used by the SkyNET drone. Black dots represent targets. In b the targets are networks. In c the targets are both networks and hosts. More information: SkyNET: a 3G-enabled mobile attack drone and stealth botmaster, www.usenix.org/events/woot11/t … final_files/Reed.pdfAbstractSkyNET is a stealth network that connects hosts to a botmaster through a mobile drone. The network is comprised of machines on home Wi-Fi networks in a proximal urban area, and one or more autonomous attackdrones. The SkyNET is used by a botmaster to commandtheir botnet(s) without using the Internet. The drones are programmed to scour an urban area and compromise wireless networks. Once compromised, the drone attacks the local hosts. When a host is compromised it joins both the Internet-facing botnet, and the sun-facing SkyNET. Subsequent drone ﬂights are used to issue command and control without ever linking the botmaster to the botnet via the Internet. Reverse engineering the botnet, or enumerating the bots, does not reveal the identity of the botmaster. An analyst is forced to observe the autonomous attack drone to bridge the command and control gap. In this paper we present a working example, SkyNET complete with a prototype attack drone, discuss the reality of using such a command and control method, and provide insight on how to prevent against such attacks.via Technology Review (PhysOrg.com) — Sven Dietrich, an assistant professor in computer science at the Stevens Institute of Technology, and two of his students have given a demonstration of an aerial drone, that they say could be used to spy on wireless networks, at last month’s USENIX Security Conference. In their presentation, and paper, they say that such drones could be used to move close enough to WiFi connections to eavesdrop or potentially serve as a control unit in a botnet. Dietrich says such a drone could also be fitted with a solar panel to keep the battery charged, which would allow it to park near a vulnerable site and do its dirty work almost indefinitely. To make things even easier for the shady characters who wish to quietly plug in to a weakly protected site, the drone can be directed to its target using a 3G smartphone.This is not the first time that someone has shown that wireless networks could be compromised by remotely controlled aircraft. A demonstration of a reconfigured Army drone following a cell phone signal was shown at the recent Black Hat security conference for example.The point in these demonstrations is not to scare people, though they most certainly might do just that, but to highlight the risks people and companies take when they don’t properly secure their WiFi networks, and to hopefully incite others to find ways to make future systems more secure so that users won’t be so vulnerable to such attacks. Citation: Group shows botnet threat in the future may come from the sky (2011, September 9) retrieved 18 August 2019 from https://phys.org/news/2011-09-group-botnet-threat-future-sky.html Explore further Hacker drone launches airborne cyber attacks © 2011 PhysOrg.com The drone, essentially a toy quadricopter (helicopter with four rotors) purchased from a store and configured with a small computer, cameras, software and wireless technology cost the team just $600 to put together, which they say means that almost anyone could construct one and begin using it to listen in on private networks.While certainly the threat of such a drone eavesdropping on a private or corporate wireless network is rather unsettling, worse is the ease with which such a “toy” could be used to serve as the control unit of a botnet (large numbers of computers infected with code that allows them to be controlled by an outside source. ) Because they would be free from tethers on the ground, law enforcement would find it exceedingly difficult, if not impossible to track them down to stamp out the botnet. And that’s a very bad thing, because botnets exist primarily to steal valuable information (such as credit card and bank numbers) off of personal computers, though in some cases they are used more as a tool to bring down web portals via denial of service attacks. 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.
Play Magnetically guided movement of a microrocket at a speed of about 100 micrometers per second. Video credit: Wei Gao, et al. ©2012 American Chemical Society The scientists predict that this capability could prove especially useful for a variety of biomedical applications as well as monitoring industrial processes such as semiconductor processing. In addition, because the microrocket’s speed is directly related to the solution’s pH, the devices could be used for sensitive pH sensing, such as detecting changes in stomach acidity. With its biggest advantage of being fueled by its acidic environment, without the need for additional fuel, the microrockets could further expand the scope of micromotor applications in many directions.“With further improvements and optimization, we hope to improve and expand the working environments to milder conditions and extend the lifetime of such microrockets to longer periods,” Wang said. “We are also exploring new materials to broaden the scope of our microengines towards new environments.” (PhysOrg.com) — Recently, researchers have been designing a wide variety of self-propelled micromotors, many of which operate using an oxygen-bubble propulsion mechanism that requires a high concentration of hydrogen peroxide fuel. Since hydrogen peroxide is hazardous at high concentrations, this requirement has hindered practical applications, especially biomedical uses. Now in a new study, scientists have designed and built a new type of micromotor that propels itself through acidic environments with hydrogen bubbles, and requires no additional fuels. At extremely low pH levels, the micromotors can travel at speeds of up to 100 body lengths per second, prompting the scientists to call them “microrockets.” The microrockets are in the shape of tiny tubes, measuring about 10 micrometers long with diameters varying from 2 to 5 micrometers. The researchers fabricated the tubes out of the common polymer polyaniline (PANI) in templates, and then electrodeposited a thin layer of zinc on the inner surface. When the microrockets are immersed in any highly acidic solution, the zinc loses electrons and – due to having a more negative redox potential than hydrogen – promotes the production of hydrogen bubbles. The researchers experimented with using other metals, such as iron and lead, but they did not produce as many bubbles as zinc.Tests showed that the microrockets’ speed increases as the pH of the solution decreases. The fastest speed of 1,050 micrometers per second (equivalent to about 100 body lengths per second) was achieved by a 5-micrometer-diameter microrocket at a pH of -0.2. The speed decreased to about 10 micrometers per second at a pH of 1.3. Although the microckets have a limited pH range, the researchers noted that they could be useful in the stomach, which has a pH range of 0.8-2.0, as well as in some types of human serum. Time-lapse images of a microrocket (a) approaching, (b) capturing, (c) transporting, and (d) releasing a target sphere. Image credit: Wei Gao, et al. ©2012 American Chemical Society Journal information: Journal of the American Chemical Society The microrockets’ speed depends on the pH of the solution. Red and black curves represent microrockets with diameters of 5 and 2 micrometers, respectively. Image credit: Wei Gao, et al. ©2012 American Chemical Society More information: Wei Gao, et al. “Hydrogen-Bubble-Propelled Zinc-Based Microrockets in Strongly Acidic Media.” Journal of the American Chemical Society. DOI: 10.1021/ja210874s While the microrockets can move autonomously in this way, the researchers also showed that it’s possible to control their direction and even to make them pick up and release cargo. The scientists did this by depositing a magnetic layer on the microcket’s outer surface, and then magnetically guiding the device in the preferred direction. They showed that a microcket could magnetically capture a polystyrene cargo, transport it on a predetermined path, and then release it by rapidly changing the magnetic field direction. Copyright 2012 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. Tiny battery is also a nanomotor PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen The researchers, Wei Gao, Aysegul Uygun, and Joseph Wang from the University of California, San Diego, have published their study on the hydrogen-bubble-propelled microrockets in a recent issue of the Journal of the American Chemical Society.“This is the first reported example of chemically-powered microrockets that can be self-propelled without an external fuel (such as the common hydrogen peroxide),” Wang told PhysOrg.com. “Such acid-powered microrockets could greatly expand the scope of applications of nano-/microscale motors toward new extreme environments (e.g., the human stomach or silicon wet-etching baths) and could thus lead to diverse new biomedical or industrial applications ranging from targeted drug delivery or nanoimaging to the monitoring of industrial processes.” Explore further Play Slow-motion video of a microrocket self-propelled at a speed of about 500 micrometers per second. Video credit: Wei Gao, et al. ©2012 American Chemical Society Tests also showed that the lifetime of the microrockets can vary from 10 seconds to 2 minutes, depending on the rate of zinc dissolution. The more zinc the rocket has, and the higher the pH of the solution, the longer the microrocket’s lifetime. Citation: Bubble-propelled microrockets could operate in the human stomach (2012, January 18) retrieved 18 August 2019 from https://phys.org/news/2012-01-bubble-propelled-microrockets-human-stomach.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. Back view of SpeechJammer prototype. Image: arXiv:1202.6106v1 The idea is based on the fact that to speak properly, we humans need to hear what we’re saying so that we can constantly adjust how we go about it, scientists call it delayed auditory feedback. It’s partly why singers are able to sing better when they wear headphones that allow them to hear their own voice as they sing with music, or use feedback monitors when onstage. Trouble comes though when there is a slight delay between the time the words are spoken and the time they are heard. If that happens, people tend to get discombobulated and stop speaking, and that’s the whole idea behind the SpeechJammer. It’s basically just a gun that causes someone speaking to hear their own words delayed by 0.2 seconds. Front view of SpeechJammer prototype. Image: arXiv:1202.6106v1 Citation: Researchers develop ‘SpeechJammer’ gun that can quash human utterances (2012, March 2) retrieved 18 August 2019 from https://phys.org/news/2012-03-speechjammer-gun-quash-human-utterances.html © 2011 PhysOrg.com And after that, new laws will have to be written to govern their use, of course, because no matter how much people would like to force others to shut up, they’ll hate it just as much it when it’s pointed at them. Overview of SpeechJammer. Image: arXiv:1202.6106v1 [cs.HC] (PhysOrg.com) — Imagine sitting around a conference table with several of your colleagues as you hold an important meeting. Now imagine your boss pulling out what looks like a radar gun for catching speeding motorists and aiming at any of you that speak to long, very nearly instantly causing whoever is speaking to start stuttering then mumbling and then to stop speaking at all. That’s the idea behind the SpeechJammer, a gun that can be fired at people to force them to stop speaking. It’s the brainchild of Koji Tsukada and Kazutaka Kurihara, science and technology researchers in Japan. They’ve published a paper describing how it works on the preprint server arXiv. More information: SpeechJammer: A System Utilizing Artificial Speech Disturbance with Delayed Auditory Feedback, Kazutaka Kurihara, Koji Tsukada, arXiv:1202.6106v1 [cs.HC] arxiv.org/abs/1202.6106AbstractIn this paper we report on a system, “SpeechJammer”, which can be used to disturb people’s speech. In general, human speech is jammed by giving back to the speakers their own utterances at a delay of a few hundred milliseconds. This effect can disturb people without any physical discomfort, and disappears immediately by stop speaking. Furthermore, this effect does not involve anyone but the speaker. We utilize this phenomenon and implemented two prototype versions by combining a direction-sensitive microphone and a direction-sensitive speaker, enabling the speech of a specific person to be disturbed. We discuss practical application scenarios of the system, such as facilitating and controlling discussions. Finally, we argue what system parameters should be examined in detail in future formal studies based on the lessons learned from our preliminary study. To make that happen, the two attached a directional microphone and speaker to a box that also holds a laser pointer and distance sensor and of course a computer board to compute the delay time based on distance from the speaker. To make it work, the person using it points the gun at the person talking, using the laser pointer as a guide, then pulls the trigger. It works for distances up to a hundred feet.The two say they have no plans to market the device, but because the technology is so simple, it’s doubtful they could patent it anyway. The idea though is likely to spread like wildfire. Surely it won’t be long before Oscar winners are jammed instead of herded offstage by increasing the music volume. Or hecklers in a crowd silenced at a moment’s notice. And just as surely human rights advocates will decry the use of such a device by politicians or government leaders, just as consumers will demand a much smaller version that will allow them to silence people that annoy them from afar, anonymously. Explore further Researchers devise a way to make a simple quantum computer using holograms
More information: www.dragoninnovation.com/proje … 6-dash-the-diy-robot “With this campaign, we’re funding the beta development of Dash, and we need your help. We’re only producing one thousand robots, so get your Dash before we run out!” they announced on the crowdfunding site. “When you back us, you’ll be getting more than just an awesome robot. You’ll be participating in the beta development of our product,” they said. “With your help, we can bring Dash out of the lab and into everyone’s hands.”Nick Kohut, chief executive officer and co-founder of Dash Robotics, hopes their fast runners will make a difference in the price barriers that turn a lot of parents and hobbyists away from educational robots that could provide fun and learning experiences for youths. “Most educational robots today cost hundreds of dollars – that’s not realistic for most families,” said Kohut. The team, now as a company called Dash Robotics, announced Thursday that they will deliver their first robots through the crowdfunding Dragon Innovation. The latter is a crowdfunding platform, aimed at backing makers and their projects. The campaign will help the team move their robots from research prototype to the “beta” product phase, in anticipation of launching Dash commercially next year. Dash, as they hope, will carry the distinction of being the world’s fold-able, programmable, origami robot that more people can afford.The Dash kit comes with laser-cut body components, motor, transmission, and plug-and-play electronics. The assembly should take about an hour, and videos online will help show the assembly process. Once assembled, the plan is for a free app that can be used to control Dash from an iOS smartphone or tablet. The creators are developing a mobile app to control Dash robots over Bluetooth. (The team is building mobile apps so that the robot can be smartphone or tablet-controlled.) As for Android support, the team said they will work hard to support Android devices but at this point they said they could not make any guarantee. The team will support iOS devices such as iPhones and iPads that have Bluetooth 4.0. In alpha form, and unassembled, the robot runner kit is forty dollars and the robot only runs in a straight line. These will be the first to ship. In beta form, they are building steering into the device and it will be more extensible. The beta is sixty-five dollars. They aim for beta shipping in spring 2014. Fully assembled as a complete unit is one hundred dollars. For Dash Robotics, this fast runner is a first step. They are interested in enabling robots to talk to each other, which would extend the possibilities to fighting insect-like robots or cooperative insect-like robots on a mission, guided by the smartphone. At the time of this writing, they raised $21,950 out of a $64,000 goal with 26 days left to go. Citation: Dash Robotics crowdfunding ‘origami’ runner you can assemble at home (2013, September 6) retrieved 18 August 2019 from https://phys.org/news/2013-09-dash-robotics-crowdfunding-origami-runner.html Explore further (Phys.org) —A team of Berkeley PhD engineers who worked in the school’s lab explored animal locomotion strategies and shared an interest in prototypes made quickly and cheaply, particularly fast robotic runners that could be affordable and easy to explore. People found them appealing and started asking if the robots were for sale. Idea. Think origami. The team worked out a novel way to manufacture new fast-running robot prototypes quickly and cheaply. The team, Nick Kohut, Paul Birkmeyer, Andrew Gillies and Kevin Peterson, dedicated to the spirit of a maker movement, have embarked on a mission to commercially offer robot kits for less than $70 and have made their goal a crowdfunding campaign. They plan on having the robots shipped in a flat pack as a kit and then folded out and assembled by the user at home, complete with tabs and slots to guide the way. Simple electronics for controlling the robots are included with the kit. Printed inchworm robot makes self-assembly moves (w/ Video) © 2013 Phys.org 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. (Phys.org)—Astronomer Burak Ulaş, with the Izmir Turk College Planetarium in Turkey has taken his work into a musical dimension, using star oscillations as a source for a musical composition. He has uploaded a paper describing what he has done along with sheet music and an audio recording of his work to the preprint server arXiv—along with a shout-out to other pioneers in the field, from Kepler to Pythagoras to modern composer scientists Jenő Keuler and Zoltán Kolláth. Explore further More information: The Multiperiodic Pulsating Star Y Cam A as a Musical Instrument, arXiv:1507.07307 [physics.pop-ph] arxiv.org/abs/1507.07307AbstractIn this study we generate musical chords from the oscillation frequencies of the primary component of oscillating eclipsing Algol system Y Cam. The parameters and the procedure of the musical chord generation process from the stellar oscillations are described in detail. A musical piece is also composed in appropriate scale for Y Cam A by using the generated chords from the results of the asteroseismic analysis of the stellar data. The music scores and the digital sound files are provided for both the generated chords and the musical composition. Our study shows that the further orchestral compositions can be made from the frequency analysis results of several pulsating stars by using the procedure stated in present study Citation: Astronomer creates music using star oscillations (2015, August 13) retrieved 18 August 2019 from https://phys.org/news/2015-08-astronomer-music-star-oscillations.html Sheet music for the composition. Credit: arXiv:1507.07307 [physics.pop-ph] Astronomers and other star-gazers have long associated celestial bodies with music, the twinkling of some stars offers a tempting back-beat and some stars in particular offer a variety of opportunities. One such star, Y Cam A, Ulaş noted, offered enough oscillation data for its use in creating chords. It is actually a binary, which accounts for its twinkling, but instead of a steady on-off blinking, the system actually oscillates at four different frequencies. He mapped the lowest tone to the note A using the free online music synthesizer Audacity, then used that as a base to map three of the stars oscillating frequencies to notes commonly used in a chord progression popular in much of modern music—G, C, D. Playing the notes in the manner in which they were “broadcast” by Y Cam A resulted in an interesting tune, to say the least. To jazz up with the piece, quite literally, he added music he had created before (played on a piano) based on Y Cam A’s whole tones that corresponded to a diminished whole tone scale, which is often used in jazz music. The result is a mixed bag of eerie pulsating sounds combined with a simple piano melody.But that is not the end of the story, the current composition is based on just one star— Ulaş envisions using the oscillations from a multitude of other various stars to drive music played on a variety of instruments—combined they could provide the basis for an entire cosmic orchestral piece, which could be used perhaps, in video games, as the soundtrack for space based movies, or simply as something interested people could listen to while pondering the vast night sky. Journal information: arXiv © 2015 Phys.org Is that Mozart or a machine? Software can compose music in classical, pop or jazz styles
Collisions generate gas in debris disks PausePlay% buffered00:0000:00UnmuteMuteDisable captionsEnable captionsSettingsCaptionsDisabledQuality0SpeedNormalCaptionsGo back to previous menuQualityGo back to previous menuSpeedGo back to previous menu0.5×0.75×Normal1.25×1.5×1.75×2×Exit fullscreenEnter fullscreen (a) The accretion disk model with the disk surface temperature. (b) The model dust emission map derived from the disk model. This model map is roughly the same as the observed map of the disk. Credit: Lee et al. (Phys.org)—A team of researchers from the U.S. and Taiwan has captured the first clear image of a young star surrounded by an accretion disk. In their paper published in the journal Science Advances, the team describes how the image was captured and details of their find. An illustration of an accretion disk feeding a central young star, or protostar, and the gaseous jet ejected from the protostar. Credit: Yin-Chih Tsai/ASIAA (a) The accretion disk model with the disk surface temperature. (b) The model dust emission map derived from the disk model. This model map is roughly the same as the observed map of the disk. Credit: Lee et al. Jet and disk in the HH 212 protostellar system: (a) A composite image of the jet, produced by combining images from different telescopes. The orange image around the center shows the accretion disk at 200 AU resolution. (b) Close-up of the center of the dusty disk at 8 AU resolution. Asterisks mark the possible position of the central protostar. A dark lane is seen in the equator. Our solar system is shown in the lower right corner for size comparison. (c) An accretion disk model that can reproduce the observed dust emission in the disk. Credit: ALMA (ESO/NAOJ/NRAO)/Lee et al. Jet and disk in the HH 212 protostellar system: (a) A composite image of the jet, produced by combining images from different telescopes. The orange image around the center shows the accretion disk at 200 AU resolution. (b) Close-up of the center of the dusty disk at 8 AU resolution. Asterisks mark the possible position of the central protostar. A dark lane is seen in the equator. Our solar system is shown in the lower right corner for size comparison. (c) An accretion disk model that can reproduce the observed dust emission in the disk. Credit: ALMA (ESO/NAOJ/NRAO)/Lee et al. Explore further © 2017 Phys.org Astrophysics have theorized that accretion disks form around young stars acting as food, helping the young star to grow bigger. Such an accretion disk would also make up the material that would over time accrete into planets. But until now, no clear image of an accretion disk had been made because the technology to do so did not exist. Now, thanks to hard work by the team and the ALMA radio telescope in Chile, that has changed.ALMA came online just four years ago—at a cost of $1.4 billion, it holds the record for the most expensive radio telescope ever built. But it also offers unprecedented resolution, capturing images in sharp detail that have appeared as fuzzy blobs in prior images. That resolution allowed the researchers to zoom in on a young star named IRAS 05413-0104 (part of the HH212 system and believed to be just 40,000 years old) that had around it a rotating accretion disk. Such disks are believed to be made of matter such as silicate, iron and other interstellar matter, and provide a steady source of food for the star. And because the disks are triple layered with brighter outer layers, the researchers describe it as looking like a hamburger. More information: Chin-Fei Lee et al. First detection of equatorial dark dust lane in a protostellar disk at submillimeter wavelength, Science Advances (2017). DOI: 10.1126/sciadv.1602935AbstractIn the earliest (so-called “Class 0”) phase of Sun-like (low-mass) star formation, circumstellar disks are expected to form, feeding the protostars. However, these disks are difficult to resolve spatially because of their small sizes. Moreover, there are theoretical difficulties in producing these disks in the earliest phase because of the retarding effects of magnetic fields on the rotating, collapsing material (so-called “magnetic braking”). With the Atacama Large Millimeter/submillimeter Array (ALMA), it becomes possible to uncover these disks and study them in detail. HH 212 is a very young protostellar system. With ALMA, we not only detect but also spatially resolve its disk in dust emission at submillimeter wavelength. The disk is nearly edge-on and has a radius of ~60 astronomical unit. It shows a prominent equatorial dark lane sandwiched between two brighter features due to relatively low temperature and high optical depth near the disk midplane. For the first time, this dark lane is seen at submillimeter wavelength, producing a “hamburger”-shaped appearance that is reminiscent of the scattered-light image of an edge-on disk in optical and near infrared light. Our observations open up an exciting possibility of directly detecting and characterizing small disks around the youngest protostars through high-resolution imaging with ALMA, which provides strong constraints on theories of disk formation. Journal information: Science Advances Play Video explaining how a “dusty hamburger” (an accretion disk) feeds a central young star, or protostar, during the onset of an extra-solar system. Credit: Chin-Fei Lee/Lauren/ASIAA The captured image lays to rest one critique of the prediction of accretion disks around young stars, which was that the magnetic field from the core of the star would be so strong that it would prevent the accretion disk from spinning, thus preventing its ability to gather matter. That is clearly not the case, as the new image shows. Also seen in the image were gaseous jets ejected from the star, which appear to pierce the hamburger at its center.It is believed that more information about the formation of stars will contribute to understanding both the history of our sun and how planets form, perhaps offering a better way of filtering star systems while searching for signs of life beyond our own planet. Citation: First clear image made of accretion disk surrounding young star (2017, April 20) retrieved 18 August 2019 from https://phys.org/news/2017-04-image-accretion-disk-young-star.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.
Extraterrestrial sources of radiation with a regular periodicity, known as pulsars, are usually detected in the form of short bursts of radio emission. Radio pulsars are generally described as highly-magnetised, rapidly rotating neutron stars with a lighthouse beam of radiation that produces the pulsed emission.However, finding new, long-period radio pulsars with a spin period of over 5.0 seconds is challenging for astronomers. Notably, only five of the 10 longest-period pulsars known have been found in periodicity searches, mainly due to their consistently larger aggregated flux over time.Recently, a group of researchers led by Chia Min Tan of the Jodrell Bank Centre for Astrophysics in Manchester, UK, has found a new radio pulsar with a relative long spin period.The detection was made in July 2017, using the LOw Frequency ARray (LOFAR) radio telescope network located mainly in the Netherlands, as part of the LOTAAS survey. LOTAAS is an all-Northern-sky survey for pulsars and fast transients at a central observing frequency of 135 MHz.Follow-up observations of the newly found pulsar were conducted using various ground-based observatories, including Green Bank Telescope, Lovell Telescope and Nancay Telescope.”We subsequently detected pulsations from the pulsar in the interferometric images of the LOFAR Two-meter Sky Survey, allowing for sub-arcsecond localization,” the astronomers wrote in the paper.Located some 5,200 light years away from the Earth, PSR J0250+5854 is a rotation-powered pulsar, what means the loss of rotational energy of the star provides the power for the radio emission. It has a spin period of approximately 23.5 seconds, which makes it the slowest-spinning radio pulsar known.Moreover, PSR J0250+5854 also has the slowest spin period when compared to any other known magnetars and X-ray dim isolated neutron stars (XDINSs). The authors of the paper noted that the similarity of the rotational parameters of the newly detected pulsar to the XDINSs and magnetars indicates a possible connection between them.The researchers also found that PSR J0250+5854 has surface magnetic field strength of 26 trillion G, age of 13.7 million years and spin-down luminosity of 82 octillion erg/s. According to the paper, these values suggest a dipolar magnetic field configuration in this pulsar.In concluding remarks, the scientists emphasized the importance of their discovery, noting that it has significantly expanded the known range of rotation-powered pulsar periods. They added that LOTAAS has the potential in discovering more slow-spinning pulsars similar to PSR J0250+5854 or even with slower spin periods. Explore further © 2018 Phys.org More information: LOFAR discovery of a 23.5-second radio pulsar, arXiv:1809.00965 [astro-ph.HE] arxiv.org/abs/1809.00965 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. An international team of astronomers has discovered a new radio pulsar as part of the LOFAR Tied-Array All-Sky Survey (LOTAAS). The newly detected object, designated PSR J0250+5854, turns out to be the slowest-spinning radio pulsar known to date. The finding is reported in a paper published September 4 on arXiv.org. Discovery plot of PSR J0250+5854, folded at the fundamental period of 23.535 s, as inferred by the harmonically related candidates from the same observation. Note that, in the discovery observation, there was no candidate identified at the fundamental period itself. Credit: Tan et al., 2018. Citation: Slowest-spinning radio pulsar detected by astronomers (2018, September 17) retrieved 18 August 2019 from https://phys.org/news/2018-09-slowest-spinning-radio-pulsar-astronomers.html New pulsar discovered during a search for a companion to a low-mass white dwarf
The Canadian High Commission, in collaboration with Seher, is organizing Autumn Sonata, an exhibition of photographs by Tarun Mathur, capturing the beauty of autumn in Canada, at Alliance Francaise in Lodhi Road from 26 to 31 October. ‘I wanted to do some work based on the theme Autumn for which I did lots of research on Internet. Canada, especially its east coast, is extremely beautiful during the onset of Autumn. So I decided to go and work there,’ said Mathur. Also Read – ‘Playing Jojo was emotionally exhausting’Giving details of the project, the photographer said, ‘There are vast areas dedicated to nature and wildlife in Canada called Provincial Parks which are located near the big cities. In October last year, I travelled from Toronto to Algonquin Park, Mont Tremblant National Park and then to Vancouver to capture the beautiful landscape. This year I wanted to shoot in the Rocky Mountains so I started from Calgary and went to Banff, Jasper and Edmonton and from there to a few parks in Saskatchewan like Prince Albert Park and Cypress Hills park.’ Also Read – Leslie doing new comedy special with NetflixMathur also rued that there aren’t much to see in India during autumn. ‘In India, we don’t see much of autumn so maple leaves are totally unknown to us. I want to highlight the manner in which Canada protects and preserves its natural environment and wildlife. We should do the same in our country,’ Mathur said.Mathur’s tryst with the lens started with print media. After working with some newspapers, he decided to turn his hobby into a full time profession. He learnt the tricks of the trade under the guidance of veteran photographer Kasinath. ‘I began as a photo journalist while in college but later drifted away due to several reasons. I am now making a comeback after 25 years with this project,’ said Mathur.According to Mathur, some of the best places to see the beauty of autumn are in Canada, New Zealand, Finland and Norway where population is comparatively less. ‘In India, the ideal location would be Kashmir but I haven’t seen the valley yet,’ he said. The exhibition comprises several photographs priced between Rs 12,000 and Rs 15000.DETAILAt: Alliance Francaise,72, Lodhi Estate, Lodi RoadWhen: 26 October to 31 October Timings:11am to 7 pmPhone: 4350 0200