Jonathan O'Callaghan

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    Squishy Neutron Star Setback Dampens Hopes of Exotic Matter

    Groundbreaking results show that neutron stars of different masses may have the same size—upending astrophysical models.

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    How Maxwell’s Demon Continues to Startle Scientists

    The thorny thought experiment has been turned into a real experiment—one that physicists use to probe the physics of information.

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    New Kind of Space Explosion Reveals the Birth of a Black Hole

    A supernova-like explosion dubbed the Camel appears to be the result of a newborn black hole eating a star from the inside out.

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    ‘Unicorn’ Discovery Points to a New Population of Black Holes

    Small black holes were nowhere to be found, leading astronomers to wonder if they didn’t exist at all. Now a series of findings, including a “unicorn” black hole, has raised hopes of solving the decade-long mystery.