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    Category Astronomy/Space

    Some Black Holes Erase your Past

    February 22, 2018, Categories  Physics, Astronomy/Space

    A spacetime diagram of the gravitational collapse of a charged spherical star to form a charged black hole. An observer traveling across the event horizon will eventually encounter the Cauchy horizon, the boundary of the region of spacetime that can be predicted from the initial data. UC Berkeley's Peter Hintz and his colleagues found that a region of spacetime, denoted by a question mark, cannot be predicted from the initial data in a universe with accelerating expansion, like our own. This violates the principle of strong cosmic censorship. Credit: APS/Alan Stonebraker

    A spacetime diagram of the gravitational collapse of a charged spherical star to form a charged black hole. An observer traveling across the event horizon will eventually encounter the Cauchy horizon, the boundary of the region of spacetime that can be predicted from the initial data. UC Berkeley’s Peter Hintz and his colleagues found that a region of spacetime, denoted by a question mark, cannot be predicted from the initial data in a universe with accelerating expansion, like our own. This violates the principle of strong cosmic censorship. Credit: APS/Alan Stonebraker

    Einstein’s equations allow a non-determinist future inside some black holes. Physicists insist on determinism: your past and present determine your future uniquely, per Einstein’s equations of general relativity...

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    Amateur astronomer captures rare 1st Light from Massive Exploding Star

    February 22, 2018, Categories  Astronomy/Space

    Supernova 2016gkg (indicated by red bars) in the galaxy NGC 613, located about 40 million light years from Earth in the constellation Sculptor. Credit: Image by UC Santa Cruz and Las Campanas Observatory, Chile

    Supernova 2016gkg (indicated by red bars) in the galaxy NGC 613, located about 40 million light years from Earth in the constellation Sculptor. Credit: Image by UC Santa Cruz and Las Campanas Observatory, Chile

    First observation of optical light from shock breakout in a supernova explosion. First light from a supernova is hard to capture; no one can predict where and when a star will explode. An amateur astronomer has now captured on film this first light, emitted when the exploding core hits the star’s outer layers: shock breakout. Subsequent observations by astronomers using the Lick and Keck observatories helped identify it as a Type IIb supernova that slimmed down from 20 to 5 solar masses before exploding.

    During tests of a new camera, Víctor Buso captured images of a distant galaxy b...

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    Laser-ranged Satellite measurement now accurately reflects Earth’s Tidal perturbations

    February 21, 2018, Categories  Astronomy/Space

    Laser-ranged satellite measurement now accurately reflects Earth's tidal perturbations

    The Lustbühel Satellite Laser Tacking. Credit: Jörg Weingrill (CC BY 2.0 [5])

    The most precise ever laser satellite measurement method provides new clues to relativity. Tides on Earth have a far-reaching influence, including disturbing satellites’ measurements by affecting their motion. This disturbance can be studied using a model for the gravitational potential of Earth, taking into account the fact that Earth’s shape is not spherical. The LAser RElativity Satellite (LARES), is the best ever relevant test particle to move in Earth’s gravitational field.

    In a new study published in EPJ Plus, LARES proves its efficiency for high-precision probing of General Relativity and fundamental physics...

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    Magnetic field traces Gas and Dust Swirling around Supermassive Black Hole

    February 21, 2018, Categories  Astronomy/Space

    The colour scale in the image shows the amount of infrared (heat) radiation coming from warm dust particles in the filaments and luminous stars within a light year of the Galactic centre. The position of the black hole is indicated by an asterisk. The lines trace the magnetic field directions and reveal the complex interactions between the stars and the dusty filaments, and the impact that they and the gravitational force has on them. Credit: E. Lopez-Rodriguez / NASA Ames / University of Texas at San Antonio. Click for a larger image

    The colour scale in the image shows the amount of infrared (heat) radiation coming from warm dust particles in the filaments and luminous stars within a light year of the Galactic centre. The position of the black hole is indicated by an asterisk. The lines trace the magnetic field directions and reveal the complex interactions between the stars and the dusty filaments, and the impact that they and the gravitational force has on them. Credit: E. Lopez-Rodriguez / NASA Ames / University of Texas at San Antonio. Click for a larger image

    Astronomers reveal a new high resolution map of the magnetic field lines in gas and dust swirling around the supermassive black hole at the centre of our Galaxy, published in a new paper in Monthly Notices of the Royal Astronomical Society...

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