Keyword: magnetism

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  • A Diamond the Size of Earth - is this Jupiter's core?

    12/28/2018 10:47:49 AM PST · by Red Badger · 57 replies
    www.guide-to-the-universe.com ^ | 12/28/2018 - Undated | Staff
    In his book "2061 - Odyssey Three" (the third of his Space Odyssey series), Arthur C. Clarke put forward the intriguing proposal that the core of the planet Jupiter was, in fact, a diamond the size of Earth. Now Clarke, even though a science fiction author of some repute, had a science background and always tried to bring rigorous scientific accuracy to his stories. So, could his proposition be possible? The somewhat predictable answer is - we don't know. But we can analyse the possibility within known scientific parametres, to see if it is, at least, possible. For diamond to...
  • Juno Finds that Jupiter’s Gravitational Field is “Askew”

    10/27/2017 7:55:03 AM PDT · by BenLurkin · 29 replies
    Jupiter’s gravity field varies with depth, which indicated that material is flowing as far down as 3,000 km (1,864 mi). Combined with information obtained during previous perijoves, this latest data suggests that Jupiter’s core is small and poorly defined. This flies in the face of previous models of Jupiter, which held that the outer layers are gaseous while the interior ones are made up of metallic hydrogen and a rocky core. ... Another interesting find was that Jupiter’s gravity field varies with depth, which indicated that material is flowing as far down as 3,000 km (1,864 mi). Combined with information...
  • A Whole New Jupiter: First Science Results from NASA’s Juno Mission

    05/25/2017 5:04:05 PM PDT · by BenLurkin · 16 replies
    nasa ^ | May 25, 2017 | Dwayne Brown / Laurie Cantillo
    Early science results from NASA’s Juno mission to Jupiter portray the largest planet in our solar system as a complex, gigantic, turbulent world, with Earth-sized polar cyclones, plunging storm systems that travel deep into the heart of the gas giant, and a mammoth, lumpy magnetic field that may indicate it was generated closer to the planet’s surface than previously thought. “We are excited to share these early discoveries, which help us better understand what makes Jupiter so fascinating,” said Diane Brown, Juno program executive at NASA Headquarters in Washington. "It was a long trip to get to Jupiter, but these...
  • Most Recent Reversal of Earth’s Magnetic Field Lasted 22,000 Years

    08/08/2019 2:00:05 PM PDT · by BenLurkin · 20 replies
    sci-news.com ^ | 08/08/2019
    The researchers combined magnetic readings and radioisotope dating of samples from seven lava flow sequences to recreate the magnetic field over a span of about 70,000 years centered on the latest geomagnetic reversal. They accurately dated the lava flows by measuring the argon produced from radioactive decay of potassium in the rocks. They found that the final reversal was quick by geological standards, less than 4,000 years. But it was preceded by an extended period of instability that included two excursions — temporary, partial reversals — stretching back another 18,000 years. The lava flow data was corroborated by magnetic readings...
  • New Laws of Attraction: Scientists Print Magnetic Liquid Droplets

    07/20/2019 5:18:22 PM PDT · by BenLurkin · 15 replies
    lbl.gov ^ | July 18, 2019 | Theresa Duque
    Inventors of centuries past and scientists of today have found ingenious ways to make our lives better with magnets – from the magnetic needle on a compass to magnetic data storage devices and even MRI body scan machines. All of these technologies rely on magnets made from solid materials. But what if you could make a magnetic device out of liquids? Using a modified 3D printer, a team of scientists at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have done just that. Their findings, to be published July 19 in the journal Science, could lead to a...
  • Ancient Tree With Record of Earth's Magnetic Field Reversal in Its Rings Discovered

    07/15/2019 9:21:19 AM PDT · by SunkenCiv · 93 replies
    Newsweak ^ | Thursday, July 4, 2019 | Hannah Osborne
    An ancient tree that contains a record of a reversal of Earth's magnetic field has been discovered in New Zealand. The tree -- an Agathis australis, better known as its M&Ccedilori name kauri -- was found in Ngawha, on New Zealand's North Island, during excavation work for the expansion of a geothermal power plant, stuff.nz reports. The tree, which had been buried in 26 feet of soil, measures eight feet in diameter and 65 feet in length. Carbon dating revealed it lived for 1,500 years, between 41,000 and 42,500 years ago... The lifespan of the kauri tree covers a point...
  • Controllable fast, tiny magnetic bits

    01/04/2019 7:06:59 PM PST · by BenLurkin · 11 replies
    Phys.org ^ | January 4, 2019 by | Denis Paiste, Massachusetts Institute of Technology
    [A] bit of heat production from resistance is a desirable characteristic in metallic thin films for spintronic applications such as solid-state computer memory. Similarly, while defects are often undesirable in materials science, they can be used to control creation of magnetic quasi-particles known as skyrmions. In separate papers published this month in the journals Nature Nanotechnology and Advanced Materials, researchers in the group of MIT Professor Geoffrey S.D. Beach and colleagues in California, Germany, Switzerland, and Korea, showed that they can generate stable and fast moving skyrmions in specially formulated layered materials at room temperature, setting world records for size...
  • {Simulated] Geomagnetic jerks finally reproduced and explained

    04/22/2019 1:23:36 PM PDT · by BenLurkin · 22 replies
    Phys.org ^ | April 22, 2019
    The Earth's magnetic field experiences unpredictable, rapid, and intense anomalies that are known as geomagnetic jerks. Initially described in 1978, geomagnetic jerks are unpredictable events that abruptly accelerate the evolution of the Earth's magnetic field, and skew predictions of its behaviour on a multi-year scale. The Earth's magnetic field is produced by the circulation of matter within its metallic core, via the energy released when this core cools. Researchers know of two types of movements that cause two types of variations in the magnetic field: those resulting from slow convection movement, which can be measured on the scale of a...
  • Shifting North Magnetic Pole Forces Unprecedented Navigation Fix

    01/11/2019 9:23:46 PM PST · by artichokegrower · 99 replies
    gCaptain ^ | January 11, 2019 | Alister Doyle
    Rapid shifts in the Earth’s north magnetic pole are forcing researchers to make an unprecedented early update to a model that helps navigation by ships, planes and submarines in the Arctic, scientists said.
  • Earth’s magnetic pole is on the move, fast. And we don’t know why

    01/12/2019 9:17:53 AM PST · by shove_it · 66 replies
    News Corp Australia Network ^ | 12 Jan 2019 | Jamie Seidel
    Earth’s magnetic field is what allows us to exist. It deflects harmful radiation. It keeps our water and atmosphere in place. But now it’s acting up — and nobody knows why. Planet Earth is alive. Deep beneath its skin, its life blood — rivers of molten iron — pulse around its core. And this mobile iron is what generates the magnetic field that causes auroras — and keeps us alive. But, according to the science journal Nature, something strange is going on deep down below. It’s causing the magnetic North Pole to ‘skitter’ away from Canada, towards Siberia. “The magnetic...
  • Scripps researchers discover new force driving Earth's tectonic plates

    07/06/2011 12:16:41 PM PDT · by decimon · 20 replies · 1+ views
    'Hot spots' of plume from deep Earth could propel plate motions around globeBringing fresh insight into long-standing debates about how powerful geological forces shape the planet, from earthquake ruptures to mountain formations, scientists at Scripps Institution of Oceanography at UC San Diego have identified a new mechanism driving Earth's massive tectonic plates. Scientists who study tectonic motions have known for decades that the ongoing "pull" and "push" movements of the plates are responsible for sculpting continental features around the planet. Volcanoes, for example, are generally located at areas where plates are moving apart or coming together. Scripps scientists Steve Cande...
  • Life is found in deepest layer of Earth's crust

    11/19/2010 1:25:40 PM PST · by Fractal Trader · 120 replies
    The New Scientist ^ | 18 November 2010 | Michael Marshall
    IT'S crawling with life down there. A remote expedition to the deepest layer of the Earth's oceanic crust has revealed a new ecosystem living over a kilometre beneath our feet. It is the first time that life has been found in the crust's deepest layer, and an analysis of the new biosphere suggests life could exist lower still. On a hypothetical journey to the centre of the Earth starting at the sea floor, you would travel through sediment, a layer of basalt, and then hit the gabbroic layer, which lies directly above the mantle. Drilling expeditions have reached this layer...
  • Breakthrough Achieved in Explaining Why Tectonic Plates Move the Way They Do

    07/16/2010 7:42:12 AM PDT · by decimon · 40 replies · 2+ views
    Scripps Institution of Oceanography ^ | July 15, 2010 | Unknown
    Researchers at Monash University and Scripps Institution of Oceanography identify movements of plate and plate boundaries; could substantially improve models of tectonic motionScripps Institution of Oceanography / University of California, San DiegoA team of researchers including Scripps Institution of Oceanography, UC San Diego geophysicist Dave Stegman has developed a new theory to explain the global motions of tectonic plates on the earth's surface. The new theory extends the theory of plate tectonics - a kinematic description of plate motion without reference to the forces behind it - with a dynamical theory that provides a physical explanation for both the motions...
  • Sea floor records ancient Earth

    03/23/2007 11:06:03 PM PDT · by Ernest_at_the_Beach · 66 replies · 4,679+ views
    BBC ^ | Friday, 23 March 2007, 09:09 GMT | Jonathan Fildes Science and technology reporter, BBC News
    The ancient sea floor was discovered in southwest Greenland A sliver of four-billion-year-old sea floor has offered a glimpse into the inner workings of an adolescent Earth.The baked and twisted rocks, now part of Greenland, show the earliest evidence of plate tectonics, colossal movements of the planet's outer shell. Until now, researchers were unable to say when the process, which explains how oceans and continents form, began. The unique find, described in the journal Science, shows the movements started soon after the planet formed. "Since the plate tectonic paradigm is the framework in which we interpret all modern-day geology,...
  • Amazon River Once Flowed in Opposite Direction

    10/24/2006 9:54:37 PM PDT · by SunkenCiv · 36 replies · 505+ views
    PhysOrg ^ | October 24, 2006 | University of North Carolina at Chapel Hill
    Russell Mapes, a graduate student from Grass Valley, Calif., ...explains that these sediments of eastern origin were washed down from a highland area that formed in the Cretaceous Period, between 65 million and 145 million years ago, when the South American and African tectonic plates separated and passed each other. That highland tilted the river's flow westward, sending sediment as old as 2 billion years toward the center of the continent. A relatively low ridge, called the Purus Arch, which still exists, rose in the middle of the continent, running north and south, dividing the Amazon's flow - eastward toward...
  • Ice Ages Blamed On Tilted Earth

    04/30/2006 4:35:48 PM PDT · by blam · 77 replies · 1,750+ views
    Live Science ^ | 3-30-2005
    Ice Ages Blamed on Tilted Earth By Michael Schirber LiveScience Staff Writer posted: 30 March 2005 In the past million years, the Earth experienced a major ice age about every 100,000 years. Scientists have several theories to explain this glacial cycle, but new research suggests the primary driving force is all in how the planet leans. The Earth’s rotation axis is not perpendicular to the plane in which it orbits the Sun. It's offset by 23.5 degrees. This tilt, or obliquity, explains why we have seasons and why places above the Arctic Circle have 24-hour darkness in winter and constant...
  • Earth’s magnetic field is acting up and geologists don’t know why

    01/10/2019 7:52:13 PM PST · by BenLurkin · 126 replies
    Nature ^ | 09 January 2019 | Alexandra Witze
    The magnetic pole is moving so quickly that it has forced the world’s geomagnetism experts into a rare move. On 15 January, they are set to update the World Magnetic Model, which describes the planet’s magnetic field and underlies all modern navigation, from the systems that steer ships at sea to Google Maps on smartphones. The most recent version of the model came out in 2015 and was supposed to last until 2020 — but the magnetic field is changing so rapidly that researchers have to fix the model now. The problem lies partly with the moving pole and partly...
  • 'True polar wander' may have caused ice age

    11/20/2018 5:32:39 PM PST · by BenLurkin · 34 replies
    phys.org ^ | November 19, 2018, | Rice University
    Like any spinning object, Earth is subject to centrifugal force, which tugs on the planet's fluid interior. At the equator, where this force is strongest, Earth is more than 26 miles larger in diameter than at the poles. Gordon said true polar wander may occur when dense, highly viscous bumps of mantle build up at latitudes away from the equator. If the mantle anomalies are massive enough, they can unbalance the planet, and the equator will gradually shift to bring the excess mass closer to the equator. The planet still spins once every 24 hours and true polar wander does...
  • Researchers find fast flip in Earth’s magnetic field

    08/23/2018 12:39:17 PM PDT · by BenLurkin · 22 replies
    earthsky.org ^ | | August 22, 2018 | Deborah Byrd
    A research team led by scientists in Taiwan and [Red] China announced on August 21, 2018, that Earth’s protective magnetic field has undergone relatively rapid shifts in the past, including one lasting just two centuries. That’s fast in contrast to the thousands of years thought to be needed for a magnetic pole reversal, an event whereby magnetic south becomes magnetic north and vice versa. Such an event might leave Earth with a substantially reduced magnetic field for some unknown period of time, exposing our world to dangerous effects from the sun. If it occurred in today’s world of ubiquitous electric...
  • Africa PHENOMENON threatens to FLIP Earth's magnetic field, taking the poles with it

    03/08/2018 10:41:30 AM PST · by SunkenCiv · 101 replies
    Express.co.uk ^ | Wednesday, March 7, 2018 | Sakura Evans
    New research shows the most significant weakening is happening under Africa which has been dubbed the 'South Atlantic Anomaly' (SAA). As well as giving us our north and south poles, the magnetic field blankets the Earth, protecting it from solar winds and cosmic radiation. The forcefield has weakened significantly over the past 160 years and scientists now suggest it could be in the process of flipping. Such a change would be a switch in magnetic polarity and would see compasses point south rather than north. Scientists believe such an occurrence has actually happened several times in the history of our...