Galactic nuclei offer some indication of axionlike particles

first_imgRight now, there are experiments going on in many laboratories, attempting to determine whether axionlike particles really do exist. One is happening at CERN, and that is the experiment Burrage is most interested in. “The experimenters are using what is called the CERN Axion Solar Telescope,” she says. “It has a cap on the end of a telescope pointed at the sun that would keep out photons. Axionlike particles, though, would pass through the cap. Then a magnetic field would be passed through the telescope, changing any axionlike particles into photons. If you could see light, even with the cap on, it would be a good indicator of the existence of these particles.” Other experiments are going on at Fermi Lab and at DESY, and involve a similar process that would result in the appearance of light “passing through” a thick barrier.At the present time, though, Burrage and her colleagues are interested in looking at the dimming results of other astronomical objects. “We are interested in the lab results of the experiments with axionlike particles, but we are not involved. Instead, we are looking to see if other types of astronomical objects are affected as the way active galactic nuclei are. If these effects are seen in observations of other objects, the case for axionlike particles is strengthened.”More information: Clare Burrage, Anne-Christine Davis, Douglas J. Shaw, “Active Galactic Nuclei Shed Light on Axionlike Particles,” Physical Review Letters (2009). Avialable online: link.aps.org/doi/10.1103/PhysRevLett.102.201101 . Copyright 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 This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Citation: Galactic nuclei offer some indication of axionlike particles (2009, May 28) retrieved 18 August 2019 from https://phys.org/news/2009-05-galactic-nuclei-indication-axionlike-particles.html (PhysOrg.com) — “Axionlike particles are interesting because they come up regularly when scientists study string theory. By looking at their properties, you hope to learn about string theory, or some other unified theory of physics. From a cosmological point of view, axionlike particles are of interest because they could be connected to dark energy,” Clare Burrage tells PhysOrg.com. The main hiccup in this study of axionlike particles, however, is the fact that their existence – much like their cousins, axions – has yet to be proven. Explore further Burrage is a scientist at Deutsches Elektonen-Synchrotron DESY in Hamburg, Germany. She believes that some cosmological evidence for axionlike particles might have been found. Along with Anne-Christine Davis at the Centre for Mathematical Sciences in Cambridge, U.K., and Douglas Shaw at Queen Mary University of London, Burrage has been studying luminosity relations in active galactic nuclei. The team believes that their results offer a good case for the existence of axionlike particles, which are thought to have low mass and weak interactions. Their work is available in Physical Review Letters: “Active Galactic Nuclei Shed Light on Axionlike Particles.”“For a long time, it has been speculated that a magnetic field could be used to change photons into axionlike particles. It is possible to look for these particles in the laboratory, and it is also possible to look for them using astronomy. We are looking for axionlike particles in astronomy, first by comparing observations of active galactic nuclei to what we expect to be the effects of the presence of axionlike particles.”Active galactic nuclei are compact regions at the centers of galaxies. These nuclei are characterized by higher than normal luminosity. Using galactic centers for reference has long been a practice when discovering distant objects and determining cosmic evolution. Burrage and her peers suggest that active galactic nuclei appear dimmer than they should, due to the presence of axionlike particles. “We have seen in the past that if photons pass through a magnetic field, like one might have near galactic nuclei, and they are converted to axionlike particles, you would lose a lot of light,” she explains. “You would see a much dimmer object than expected. That is what we are seeing when we look at the precision measurements we have studied.”Burrage points out that, while the results of this data crunching are encouraging, they are not conclusive. “The problem with astronomy is that you can’t go out and poke the galaxy,” she says. “There’s a lot about the physics that we don’t understand. There could be another explanation that mimics the effects we are looking for. We need to see it in the lab as well, if we want to back up our assertion that we are dealing with axionlike particles.” 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. Is dark matter made of axions?last_img read more

New pint sized particle accelerator leads the way to clean nuclear energy

first_img(PhysOrg.com) — Researchers at Daresbury science park in Britain have offered a glimpse into what might be the future of nuclear energy production by showcasing a scaled down particle accelerator; one, that when combined with others just like it, could produce nuclear energy based on thorium, rather than uranium. Dubbed the Electron Machine with Many Applications (EMMA), the accelerator, a much smaller version of the kind used in physics research, such as the Large Hadron Collider, could be used to provide an accelerated beam necessary for the type of nuclear reaction used in a theoretical thorium plant. The EMMA ring in relation to the main ERLP (ALICE) accelerator. Thorium, named for the Norse god of thunder, is a silver-white metal found in abundance all over the planet, and is only very slightly radioactive and as such is a member of the elements known as actinides which, like uranium, occasionally spin off particles which make it useful for energy production. But unlike uranium, thorium is relatively clean because it decays much faster leaving far less reactive byproducts behind; and because it requires a constant bombardment of particles to keep it reacting, is incapable of producing a meltdown; something on the minds of people in the aftermath the Fukushima disaster.That’s where EMMA enters the picture. To produce the constant stream of particles needed to keep a thorium reaction going, an accelerator is needed, but it wouldn’t have to be the huge billion dollar kind, more like the kind you could fit in your garage, or in this case in a lab on the boggy Cheshire flatland, just east of Liverpool, where reporters from the U.K. newspaper Mail, were recently given a tour. They report that EMMA is “an object of scientific beauty…” Scientists have known since the 1950’s that thorium could be used to produce electricity, just as uranium is today; what kept them from doing so was the desire to use technology that could be used in conjunction with atomic weapons, which pushed thorium research aside due to its impracticality for such applications. Today however, things have obviously changed, several countries besides Britain are taking a very hard look at thorium and the ways it could be put to good use and at small particle accelerators too; the team in Britain is also currently at work designing the Particle Accelerator for Medical Applications (Pamela) to be used to help treat hard to reach cancer in patients. © 2010 PhysOrg.com A future energy giant? India’s thorium-based nuclear planscenter_img Explore further Citation: New pint sized particle accelerator leads the way to clean nuclear energy (2011, June 20) retrieved 18 August 2019 from https://phys.org/news/2011-06-pint-sized-particle-nuclear-energy.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.last_img read more

Meteorite find may be missing half of interstellar collision

first_img Journal information: Earth and Planetary Science Letters Citation: Meteorite find may be ‘missing half’ of interstellar collision (2014, July 1) retrieved 18 August 2019 from https://phys.org/news/2014-07-meteorite-interstellar-collision.html For several years scientists have debated the reason behind a lull, then sudden resurgence of biodiversity on planet Earth a little over 500 million years ago—some suggest the resurgence was due to a sudden major increase in the number of meteorite impacts. The increase, theorists suggest, came about due to an impact between two asteroids, likely somewhere between Jupiter and Mars. Debris from the remains of one of those objects is believed to be the source of L chondrites, which have been found in many places around the globe. But, until now, no evidence of the other asteroid has been found on Earth, putting a damper on the theory—some have suggested the second asteroid simply vaporized on impact. The meteorite found in Sweden has reignited interest, however, because it’s possible it is a piece of that second asteroid (because it appears to have been part of the same meteor shower as the L chondrites), which if true, will add a lot of credence to the entire theory that seeks to explain the sudden resurgence of life during the early part of the Ordovician period.The meteorite was found by quarry workers three years ago—other meteorites have been found in the same quarry before, but all of them were L chondrites. It was different from the other’s, the researchers noted, after studying its crystals, but was in the same rock layer and dating in the lab, suggesting it arrived during the same time period as part of a wider meteor shower. While still in the same class of primitive achondrites as L chondrites, it’s not exactly the same because of small differences in its elemental composition. The team is hopeful that the finding suggests that others will be found, hopefully some that can offer more evidence of their origin.The unique meteorite has not been given an official name yet—for now it’s simply being referred to as the “mysterious object.” The Thorsberg quarry and the Mysterious Object. (A) Thorsberg quarry on June 15, 2013. The Österplana church is seen in the back. (B) The Mysterious Object from the Glaskarten 3 bed. The meteorite is 8 × 6.5 × 2 cm in size. It was found in the youngest quarried bed of the Thorsberg quarry, at the top of the section. Credit: Earth and Planetary Science Letters, Volume 400, 15 August 2014, Pages 145–152. Explore further Research shows collision created Chelyabinsk asteroidcenter_img (Phys.org) —A team of researchers with members from the U.S., Sweden and Switzerland studying a meteorite found in a Swedish quarry is reporting that the rock is unlike anything else ever found. In their paper published in Earth and Planetary Science Letters, they suggest the meteorite might just be evidence of a collision between two asteroids millions of years ago. 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. More information: A fossil winonaite-like meteorite in Ordovician limestone: A piece of the impactor that broke up the L-chondrite parent body? Earth and Planetary Science Letters, Volume 400, 15 August 2014, Pages 145–152. www.sciencedirect.com/science/ … ii/S0012821X14003367AbstractAbout a quarter of all meteorites falling on Earth today originate from the breakup of the L-chondrite parent body ∼470 Ma ago, the largest documented breakup in the asteroid belt in the past ∼3 Ga. A window into the flux of meteorites to Earth shortly after this event comes from the recovery of about 100 fossil L chondrites (1–21 cm in diameter) in a quarry of mid-Ordovician limestone in southern Sweden. Here we report on the first non-L-chondritic meteorite from the quarry, an 8 cm large winonaite-related meteorite of a type not known among present-day meteorite falls and finds. The noble gas data for relict spinels recovered from the meteorite show that it may be a remnant of the body that hit and broke up the L-chondrite parent body, creating one of the major asteroid families in the asteroid belt. After two decades of systematic recovery of fossil meteorites and relict extraterrestrial spinel grains from marine limestone, it appears that the meteorite flux to Earth in the mid-Ordovician was very different from that of today. © 2014 Phys.orglast_img read more

JPL scientists predict future space probes will have artificial intelligence to operate

first_imgCredit: CC0 Public Domain More information: Robotic space exploration agents, Science Robotics (2017). robotics.sciencemag.org/lookup … /scirobotics.aan4831AbstractLimitations on interplanetary communications create operations latencies and slow progress in planetary surface missions, with particular challenges to narrow–field-of-view science instruments requiring precise targeting. The AEGIS (Autonomous Exploration for Gathering Increased Science) autonomous targeting system has been in routine use on NASA’s Curiosity Mars rover since May 2016, selecting targets for the ChemCam remote geochemical spectrometer instrument. AEGIS operates in two modes; in autonomous target selection, it identifies geological targets in images from the rover’s navigation cameras, choosing for itself targets that match the parameters specified by mission scientists the most, and immediately measures them with ChemCam, without Earth in the loop. In autonomous pointing refinement, the system corrects small pointing errors on the order of a few milliradians in observations targeted by operators on Earth, allowing very small features to be observed reliably on the first attempt. AEGIS consistently recognizes and selects the geological materials requested of it, parsing and interpreting geological scenes in tens to hundreds of seconds with very limited computing resources. Performance in autonomously selecting the most desired target material over the last 2.5 kilometers of driving into previously unexplored terrain exceeds 93% (where ~24% is expected without intelligent targeting), and all observations resulted in a successful geochemical observation. The system has substantially reduced lost time on the mission and markedly increased the pace of data collection with ChemCam. AEGIS autonomy has rapidly been adopted as an exploration tool by the mission scientists and has influenced their strategy for exploring the rover’s environment. Despite recent successes, such as placing roving robots on Mars and sending craft to Venus, Saturn and other parts of the solar system, space scientists all agree that space science is still difficult. It is not easy to design a craft capable of venturing out to distant points in space and have them work as designed. All manner of difficulties must be imagined and measures taken to account for them. In the future, Chien and Wegstff suggest, things are only going to get more difficult as scientists send craft farther into space. Doing so, they suggest, will require more probes, which means they will have to be a lot smarter—in many situations, they may have to carry out their entire mission without intervention from humans back on Earth. They will have to be able to learn, too, so that they can change how they go about their activities. This, the pair notes, means that they will have to be equipped with advanced artificial intelligence systems that are capable of understanding requirements and carrying out activities autonomously that will serve to achieve desired goals.Such systems, for example, will need to be able to identify situations like the difference between normal planetary conditions and a storm that has arisen. Or they might need to be able to recognize changes in season, the difference between snow and ice, or when water is moving. They will need to be able to use their tools to look at their surroundings and to choose the best parts to study, and perhaps use what they find to conduct further studies.Adding intelligence to robotic probes, the researchers suggest, could enable probes sent to places as far away as Alpha Centauri, which would take so long that the generation of scientists receiving the data will succeed the generation that launched the mission. Because of that, the probe will need to know how to do everything itself. 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. Citation: JPL scientists predict future space probes will have artificial intelligence to operate autonomously (2017, June 22) retrieved 18 August 2019 from https://phys.org/news/2017-06-jpl-scientists-future-space-probes.html NASA develops AI for future exploration of extraterrestrial subsurface oceanscenter_img Journal information: Science Robotics © 2017 Phys.org (Phys.org)—A pair of space scientists working at NASA’s Jet Propulsion Laboratory at the California Institute of Technology has written a Focus piece for the journal Science Robotics. Steve Chien and Kiri Wagstaff suggest that future space probes will be given enough intelligence to carry out much of their mission without prompts from people back on Earth. Explore furtherlast_img read more

Fossilized brains of ancient sea creatures found in northern Greenland

first_img 520-million-year-old arthropod brains turn paleontology on its head © 2018 Phys.org The fossils are from Kerygmachela kierkegaardi, a type of sea creature that lived from approximately 521 to 514 million years ago. The creatures were approximately 25 centimeters in length, had large eyes and had 11 feather-shaped swimming flaps on their sides. They also had a long, thin tail, long twin appendages on their round heads, which they apparently used for grasping prey, and, as this new evidence shows, a single-segment brain. It is the brain that is newsworthy in this new effort—prior fossilized samples of Kerygmachela have been found before, but this is the first time that fossilized brains have been uncovered. The fossilized brains, the team notes, are made of thin carbon films.The team reports that they found 15 fossilized brains in all, some of which also had associated fossilized nervous system tissue. Because the brains had just one segment, it is assumed that they were less complex than those with three segments, suggesting limited behavioral attributes. These findings call into question the assumption that the common ancestor of all arthropods and vertebrates had three-segmented brains. But, the team also notes, despite having just one segment, the creature clearly had enough brain power to survive during the Cambrian explosion. They also note that the creature’s large eyes represent an intermediate evolutionary step between creatures with very simple eyes and those with eyes that are far more complex.The fossils were located at a site named Sirius Passet on the northern tip of Greenland. The researchers found them by canvassing shale plots on land and using hammers to crack apart layers of shale which had protected the fossils from the elements over millions of years, allowing for the preservation of the fossilize brains. The fossilized brains represent some of the oldest ever found. Journal information: Nature Communications More information: Tae-Yoon S. Park et al. Brain and eyes of Kerygmachela reveal protocerebral ancestry of the panarthropod head, Nature Communications (2018). DOI: 10.1038/s41467-018-03464-wAbstractRecent discoveries of fossil nervous tissue in Cambrian fossils have allowed researchers to trace the origin and evolution of the complex arthropod head and brain based on stem groups close to the origin of the clade, rather than on extant, highly derived members. Here we show that Kerygmachela from Sirius Passet, North Greenland, a primitive stem-group euarthropod, exhibits a diminutive (protocerebral) brain that innervates both the eyes and frontal appendages. It has been surmised, based on developmental evidence, that the ancestor of vertebrates and arthropods had a tripartite brain, which is refuted by the fossil evidence presented here. Furthermore, based on the discovery of eyes in Kerygmachela, we suggest that the complex compound eyes in arthropods evolved from simple ocelli, present in onychophorans and tardigrades, rather than through the incorporation of a set of modified limbs. 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.last_img read more

From the gentlemen in fiction

first_imgWhat is all about a teenager’s passion? How many of them kick start their pursuit of dreams right from the moment as a budding enthusiast? Are they all about getting glued to their play stations on the couch? Not all of them. A 16 year old Delhi inspiration Ayush Ansal has begun his venture of becoming an author with his first novel The Gentlemen of Finance released at the Indian Habitat Center this 3 April. Ayush, born and brought up in New Delhi is pursuing his secondary education in Gordonstoun, Scotland. Also Read – ‘Playing Jojo was emotionally exhausting’The Stein Auditorium of IHC was packed with an young legion interspersed with their vanguards presided by the Minister of State for Corporate Affairs, an young Sachin Pilot, who unveiled the book. The Other guests of honor were Dr Nick Argent, Director, The British School, Vanita Uppal, Principal, Secondary, The British School and the Kapish Mishra, Managing Director, Rupa Publications.Sushil Ansal, Chancellor, Ansal University welcomed the gathering and felicitated the author in his pursuit of his dream and to develop his skills as a big wheel, as the title of the book suggests. Sachin Pilot congratulated Ayush on his efforts and to continue his pursuit of heart and mind.Ayush, an avid guitarist, who has titled the chapters of his book with his favorite songs believes that his emphasis on dedication and determination has led to him being able to balance the demands of academics with other interests.last_img read more