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  • richardmitnick 7:13 am on October 8, 2018 Permalink | Reply
    Tags: , , , , Scientists develop a new way to remotely measure Earth’s magnetic field, UBC-University of British Columbia   

    From University of British Columbia: “Scientists develop a new way to remotely measure Earth’s magnetic field” 

    U British Columbia bloc

    From University of British Columbia

    October 2, 2018

    Chris Balma
    balma@science.ubc.ca
    604.822.5082
    c 604-202-5047

    1
    Polar Mesospheric clouds. University of British Columbia researchers have helped develop a new way to remotely measure Earth’s magnetic field in the atmosphere. Credit: NASA

    Researchers in Canada, the United States and Europe have developed a new way to remotely measure Earth’s magnetic field—by zapping a layer of sodium atoms floating 100 kilometres above the planet with lasers on the ground.

    The technique, documented in Nature Communications, fills a gap between measurements made at the Earth’s surface and at much higher altitude by orbiting satellites.

    “The magnetic field at this altitude in the atmosphere is strongly affected by physical processes such as solar storms and electric currents in the ionosphere,” says Paul Hickson an astrophysicist at the University of British Columbia (UBC) and author on the paper.

    “Our technique not only measures magnetic field strength at an altitude that has traditionally been hidden, it has the side benefit of providing new information on space weather and atomic processes occurring in the region.”

    Sodium atoms are continually deposited in the mesosphere by meteors that vaporize as they enter Earth’s atmosphere. Researchers at the European Southern Observatory (ESO), the University of Mainz and UBC used a ground-based laser to excite the layer of sodium atoms and monitor the light they emit in response.

    “The excited sodium atoms wobble like spinning tops in the presence of a magnetic field,” explains Hickson. “We sense this as a periodic fluctuation in the light we’re monitoring, and can use that to determine the magnetic field strength.”

    Hickson and UBC PhD student Joschua Hellemeier developed the photon counting instrument used to measure the light coming back from the excited sodium atoms, and participated in observations conducted at astronomical observatories in La Palma.

    The ESO team, led by Bonaccini Calia, pioneered world-leading laser technology for astronomical adaptive optics used in the experiment. Project lead Felipe Pedreros and Dmitry Budker (Johannes Gutenberg University), Simon Rochester and Ronald Holzloehner (ESO), experts in laser-atom interactions, led the theoretical interpretation and modeling for the study.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U British Columbia Campus

    The University of British Columbia is a global centre for research and teaching, consistently ranked among the 40 best universities in the world. Since 1915, UBC’s West Coast spirit has embraced innovation and challenged the status quo. Its entrepreneurial perspective encourages students, staff and faculty to challenge convention, lead discovery and explore new ways of learning. At UBC, bold thinking is given a place to develop into ideas that can change the world.

     
  • richardmitnick 3:40 pm on October 2, 2018 Permalink | Reply
    Tags: , , , Sabancaya—a so-called “laboratory volcano” in the Peruvian Andes, UBC-University of British Columbia, Vital volcano insights come at a cost during UBC scientists’ summer expedition,   

    From University of British Columbia: “Vital volcano insights come at a cost during UBC scientists’ summer expedition” 

    U British Columbia bloc

    From University of British Columbia

    Oct 1, 2018
    Erik Rolfsen

    It started out like the camping trip from hell, but it turned into the research expedition of a lifetime for three University of British Columbia volcanologists.

    Colin Rowell and Johan Gilchrist, PhD students in UBC’s department of earth, ocean and atmospheric sciences, travelled in late May with professor Mark Jellinek to meet French and Peruvian research teams at Sabancaya—a so-called “laboratory volcano” in the Peruvian Andes. Such volcanoes have short and frequent eruptions that are safely viewed from a few kilometres away. The Peruvians had invaluable local knowledge of the volcano, so conditions seemed ideal for the international team to observe and collect data.

    Conditions, of course, can change.

    Rowell and Jellinek beat Gilchrist to the mountains by a day. Their first night was a harbinger of what was to come. After a slow, four-wheel drive along rocky routes that were barely marked, they hastily set up camp on an exposed plateau at 5,000 metres before night fell on the desert mountains. The temperature dropped to -25 C overnight, and they felt it.

    Tea would warm them up, but they hadn’t been able to find proper camp stove fuel in Arequipa or Chivay, the towns along their route. So they carried diesel from local gas stations in jerry cans. Cooking with diesel, they discovered, is messy.

    “We got up there the next day and spotted them and thought, ‘OK, good, they’ve settled,’” recalled Gilchrist. “Then we got closer and they were just covered in this black soot. I said, ‘What have you guys been doing up here, coal mining?’ I couldn’t believe how filthy they were after just one night.”

    They may have woken up filthy, but they also woke up to their first volcanic eruption.

    “It was absolutely awe-inspiring,” said Rowell. “That was a big morale boost. We found our stride, adjusted to the altitude, and the volcano started doing its spectacular thing.”

    1
    Members of the research team observe Sabancaya from camp, where they had set up their new Doppler radar instrument. Courtesy: Colin Rowell and Johan Gilchrist.

    2
    Sabancaya sends a plume of smoke, gas and ash into the air. Debris from its eruptions can reach a height of five kilometres. Courtesy: Colin Rowell and Johan Gilchrist.

    3
    The Doppler radar instrument developed by members of the French team can measure the volume and velocity of particles in a volcanic plume. Courtesy: Colin Rowell and Johan Gilchrist.

    4
    El Misti over Arequipa. Courtesy: Colin Rowell and Johan Gilchrist.

    Gilchrist’s late arrival had spared him a night of shivering in his tent with a soot-covered face, but for him the worst was still to come. Sometime after landing in Peru, he had picked up a stomach bug. By his third day in camp, the stomach bug, altitude sickness and partial blindness from an old eye injury that was being irritated by airborne ash had knocked him flat. He had to rest in his tent while others hiked nearby peaks for a good look at the volcano.

    To the team’s delight, the volcano erupted like clockwork every four and a half hours. They could watch plumes of volcanic rocks, gas and ash rise five kilometres against a cloudless blue sky. Rowell’s thermal camera measured the plumes’ heat and turbulence properties, while Gilchrist captured the volume and velocity of particles using a new Doppler radar instrument brought by his French colleagues. They will use that data to build computer models of how volcanic plumes behave–how high they rise, when they fall, how much ash they contain and how hot they become.

    The team was thrilled with the quantity and quality of the data, but Rowell and Jellinek were concerned about Gilchrist’s health. All he could do was crawl out of his tent, force down some food, drink hot tea and take notes by his camera. Then he’d crawl back in the tent to suffer for a few hours before the next volcanic eruption.

    Rowell and Jellinek were scheduled to leave earlier than Gilchrist, and thought they might bring their ailing partner back home as well. But when Gilchrist accompanied them back to Chivay, with its cleaner air and lower elevation, he felt recharged. His bug was subsiding, and he stayed another week to collect data from the camp below Sabancaya.

    “We went into this trip not quite knowing how it would go, and there were definitely some demoralizing moments, but we came away with a really inspiring experience and a dataset that is going to give us some unique insight,” said Rowell. “That was a really good feeling for all of us.”

    The value of the data sank in for Gilchrist near the end of his trip, when he climbed El Misti, a volcano looming over the growing city of Arequipa, home to 800,000 people. From Misti’s summit, Gilchrist could see inside its crater–a fresh, active volcano full of red rocks, crystallized lava and swirling gases. Down the slope, he saw small homes scattered throughout the foothills, illegal but tolerated settlements of rural migrants who have moved to the city for work. Those people were, and are, in the danger zone.

    “They’re right there,” Gilchrist said. “And this thing will erupt again. It has erupted in the past. When it does, I hope the people of Arequipa are ready.”

    It was a sobering reminder of why Gilchrist, Rowell, Jellinek and their colleagues do the work they do — to make the unpredictable a little more predictable, and perhaps save lives.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U British Columbia Campus

    The University of British Columbia is a global centre for research and teaching, consistently ranked among the 40 best universities in the world. Since 1915, UBC’s West Coast spirit has embraced innovation and challenged the status quo. Its entrepreneurial perspective encourages students, staff and faculty to challenge convention, lead discovery and explore new ways of learning. At UBC, bold thinking is given a place to develop into ideas that can change the world.

     
  • richardmitnick 10:02 am on August 21, 2018 Permalink | Reply
    Tags: For The First Time Physicists Know How to Measure The Force of Light's Momentum, , , , UBC-University of British Columbia   

    From University of British Columbia via Science Alert: “For The First Time, Physicists Know How to Measure The Force of Light’s Momentum” 

    U British Columbia bloc

    University of British Columbia

    ScienceAlert

    From Science Alert

    21 AUG 2018
    MICHELLE STARR

    1
    (NASA/JPL-Caltech)

    How much pressure does light exert on the matter with which it interacts? It’s a problem that’s confounded scientists for nearly 150 years – and it may now have a solution. A team of researchers have come up with a method for measuring the effect a photon has on matter.

    Even though a photon has no mass, it does have momentum, which can be defined within the framework of special relativity.

    And this momentum exerts a force. It was all the way back in 1619 that the pressure exerted by light was hypothesised. In his treatise De Cometi, German mathematician and astronomer Johannes Kepler put forth that light from the Sun exerting pressure was the reason a comet’s tail always trails away from the Sun.

    It wasn’t until 1873 that Scottish physicist James Clerk Maxwell hypothesised in A Treatise on Electricity and Magnetism that this was linked to momentum.

    Clerk Maxwell – whose work provided a critical foundation for Einstein’s work on relativity – surmised that light is a form of electromagnetic radiation that carries momentum and thus exerts pressure.

    But the momentum – and therefore the radiation pressure – of a photon is vanishingly small, which means measuring it directly is extremely tricky.

    “Until now, we hadn’t determined how this momentum is converted into force or movement,” explained engineer Kenneth Chau of the University of British Columbia Okanagan Campus in Canada.

    “Because the amount of momentum carried by light is very small, we haven’t had equipment sensitive enough to solve this.”

    Spoiler: our current technological capabilities still aren’t sensitive enough to detect the momentum of a photon directly. But Chau and colleagues from Slovenia and Brazil have figured out a way to gauge the effects of a photon’s momentum.

    They built an apparatus around a mirror. Heat shielding went around it to protect the experiment from outside interferences, while sensitive acoustic sensors were equipped.

    When they fired laser pulses at the mirror, this sent elastic waves moving across its surface. These, detected by the acoustic sensors, open the door to being able to calculate the radiation pressure being exerted by the momentum of the photons.

    “We can’t directly measure photon momentum, so our approach was to detect its effect on a mirror by ‘listening’ to the elastic waves that travelled through it,” Chau said.

    “We were able to trace the features of those waves back to the momentum residing in the light pulse itself, which opens the door to finally defining and modelling how light momentum exists inside materials.”

    This isn’t just really neat science – it could have important practical applications.

    For example, being able to accurately calculate radiation pressure could pave the way to better solar sail technology – a method of propellant-free propulsion for spacecraft that uses radiation pressure on a sail in lieu of wind.

    It could also allow for better optical tweezers, a method of trapping and manipulating incredibly small particles – down to the scale of a single atom.

    “We’re not there yet,” Chau said, “but the discovery in this work is an important step and I’m excited to see where it takes us next.”

    The research has been published in Nature Communications.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U British Columbia Campus

    The University of British Columbia is a global centre for research and teaching, consistently ranked among the 40 best universities in the world. Since 1915, UBC’s West Coast spirit has embraced innovation and challenged the status quo. Its entrepreneurial perspective encourages students, staff and faculty to challenge convention, lead discovery and explore new ways of learning. At UBC, bold thinking is given a place to develop into ideas that can change the world.

     
  • richardmitnick 12:04 pm on August 6, 2018 Permalink | Reply
    Tags: , , , , , , UBC-University of British Columbia, Vancouver Sun   

    From University of British Columbia via Vancouver Sun: “Radio telescope near Penticton opening new doors in astrophysics” 

    U British Columbia bloc

    From University of British Columbia

    via

    1

    Vancouver Sun

    August 5, 2018

    A new radio telescope near Penticton has allowed space watchers to see bursts of light travelling from a far-away galaxy in a discovery they say could open new doors in understanding the universe.

    A new radio telescope has allowed space watchers to see bursts of light travelling from a far-away galaxy in a discovery they say could open new doors in understanding the universe and the study of star systems.

    The revolutionary radio telescope housed in an observatory south of Penticton, is at the centre of the Canadian Hydrogen Intensity Mapping Experiment, or CHIME.

    CHIME Canadian Hydrogen Intensity Mapping Experiment A partnership between the University of British Columbia, the University of Toronto, McGill University, Yale and the National Research Council of Canada, at the Dominion Radio Astrophysical Observatory in British Columbia

    It is a collaboration by several North American universities, including the University of British Columbia, the University of Toronto, McGill University, Yale and the National Research Council of Canada.

    Deborah Good, a UBC PhD student working on the project, said unlike a normal radio dish, this radio telescope is made up of four cylinders containing 1,024 antennae that can measure fast, short-lived bursts of light found on the radio wave spectrum called fast radio bursts.

    Fast radio bursts are made up of photons, which are particles of light that can be dispersed by gas and dust found it space. The further away they are, the more dispersed they will be.

    The telescope was originally designed to chart hydrogen and measure the historical expansion of the universe.

    Good said the majority of the bursts they previously detected were measured around 1,400 megahertz, making the bursts detected on July 25 at 580 megahertz an illuminating find.

    While the telescope is extremely sensitive, Good said it’s a bit like looking for a needle in a haystack using a large magnifying glass.

    “If you look in the right place, you’ll find it. It’s just hard to figure out where that place is,” she said.

    Radio waves occur naturally from cosmic objects and lightning strikes, and are longer waves of light than the human eye can normally see, like the infrared and ultraviolet spectras.

    On a typical day, the telescope detects between two and 50 fast radio bursts. After a previous burst measuring 700 megahertz was spotted, Good said they were worried that might be the lowest frequency they could see with the telescope, or that perhaps they weren’t searching for the right frequencies.

    “We’re kind of relieved to see that, indeed, we get to see things in the lower half of the band,” she said during a telephone interview.

    Good likened the telescope to studying a group of college students: observing 20 college students would not necessarily give you enough data to analyze, but if you studied several thousand, the data becomes significantly deeper and allows researchers to find trends.

    “If I know there’s one guy with glasses, that doesn’t tell me if glasses are just a feature that college students can have, or if this guy is some other type of thing because he’s a college student with glasses,” Good said while explaining the importance of measuring more fast radio bursts so researchers can better understand what they’ve found so far.

    Researchers have detected several more such bursts recently, she said, but they are still measuring the information and she couldn’t go into further detail. The recent discoveries are very exciting and a bit of luck after weeks of hard work, she said.

    “With astronomy we’re trying to detect something that’s out there and we don’t get to control when it shows up,” said Good, referring to the difficulty of the experiment versus more typical scientific experiments with human control.

    For those hoping the radio bursts might be a sign of alien life, Good dispels that notion.

    “There’s a bunch of theories right now, but one thing we’re really confident about is that it’s not aliens,” she said laughing.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    U British Columbia Campus

    The University of British Columbia is a global centre for research and teaching, consistently ranked among the 40 best universities in the world. Since 1915, UBC’s West Coast spirit has embraced innovation and challenged the status quo. Its entrepreneurial perspective encourages students, staff and faculty to challenge convention, lead discovery and explore new ways of learning. At UBC, bold thinking is given a place to develop into ideas that can change the world.

     
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