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Archive for the ‘cosmology’ category: Page 224

Dec 17, 2021

Astronomers spy quartet of cavities from giant black holes

Posted by in category: cosmology

Scientists have found four enormous cavities, or bubbles, at the center of a galaxy cluster using NASA’s Chandra X-ray Observatory. This unusual set of features may have been caused by eruptions from two supermassive black holes closely orbiting each other.

Galaxy clusters are the largest structures in the universe held together by gravity. They are a mixture of hundreds or even thousands of individual galaxies, enormous amounts of hot gas, and unseen dark matter. The hot gas that pervades clusters contains much more mass than the galaxies themselves, and glows brightly in X-ray light that Chandra detects. An enormous galaxy is usually found at the center of a cluster.

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Dec 17, 2021

Black Holes Could Be Dark Matter — And May Have Existed Since the Beginning of the Universe

Posted by in category: cosmology

Did black holes form immediately after the Big Bang? How did supermassive black holes form? What is dark matter? In an alternative model for how the Universe came to be, as compared to the ‘textbook’ history of the Universe, a team of astronomers propose that both of these cosmic mysteries could be explained by so-called ‘primordial black holes’. In the graphic, the focus is on comparing the timing of the appearance of the first black holes and stars, and is not meant to imply there are no black holes considered in the standard model. Credit: ESA.

Dec 16, 2021

Killing Stars

Posted by in categories: cosmology, futurism

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When the largest of stars dies, the supernova they produce can outshine a whole galaxy, and potentially sterilize vast swathes of space. Future civilizations will need to be able to prevent or mitigate such events, though some might seek to artificially ignite a nova.

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Dec 16, 2021

Fleet of Stars

Posted by in categories: cosmology, space travel

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Interstellar travel is very time consuming, moving from star to star, but perhaps we could use stars themselves as spaceships, and move whole solar systems or even galaxies.
Today we’ll look at how to use Shkadov Thrusters, novas, supernovae, black holes and quasars to move through space, literal starships.

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Dec 16, 2021

The Universe Might Be Able to Bend the Laws of Physics All By Itself

Posted by in categories: biological, cosmology, neuroscience, physics

At this point, the paper mingles cosmology, or the study of the universe and its origins, with biology. “We ask whether there might be a mechanism woven into the fabric of the natural world, by means of which the universe could learn its laws,” the authors write. In other words, a universal law might transcend all scientific fields. That means that the laws of physics, as we know them, could be subject to higher-order laws of the universe that control them—and that we can’t even comprehend.

“Exploring links between fields is crucial because knowledge is not fundamentally compartmentalized,” says Bruce Bassett, professor at the University of Cape Town’s Department of Mathematics and head of the Cosmology Group at the African Institute of Mathematical Sciences in South Africa. We humans are simply narrow-minded. “We segment and compress knowledge into biology, and physics, and sociology because of our limited brains, and the cost of that segmentation and compression is that we easily miss the commonalities and hidden universality between branches of human knowledge.”

Dec 15, 2021

Evidence for Parallel Universes — Max Tegmark / Serious Science

Posted by in categories: computing, cosmology, quantum physics, science

Physicist Max Tegmark on predictions that cannot be observed, explanation of Universe’ fine tuning, and quantum computer.

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Dec 14, 2021

Quantum-circuit black hole lasers

Posted by in categories: cosmology, information science, quantum physics

A black hole laser in analogues of gravity amplifies Hawking radiation, which is unlikely to be measured in real black holes, and makes it observable. There have been proposals to realize such black hole lasers in various systems. However, no progress has been made in electric circuits for a long time, despite their many advantages such as high-precision electromagnetic wave detection. Here we propose a black hole laser in Josephson transmission lines incorporating metamaterial elements capable of producing Hawking-pair propagation modes and a Kerr nonlinearity due to the Josephson nonlinear inductance. A single dark soliton obeying the nonlinear Schrödinger equation produces a black hole-white hole horizon pair that acts as a laser cavity through a change in the refractive index due to the Kerr effect.

Dec 14, 2021

Watch Stars Race Around the Milky Way’s Supermassive Black Hole at Mind-Boggling Speeds

Posted by in category: cosmology

The European Southern Observatory’s Very Large Telescope Interferometer (ESO

Created in 1962, the European Southern Observatory (ESO), is a 16-nation intergovernmental research organization for ground-based astronomy. Its formal name is the European Organisation for Astronomical Research in the Southern Hemisphere.

Dec 14, 2021

Bill Gates won’t join the space race. He wants to eradicate malaria and tuberculosis instead

Posted by in categories: cosmology, Elon Musk, internet

Some of the world’s richest men are squaring off in what’s become a rivalry for the ages — the space race. Elon Musk and Jeff Bezos, the two richest men on the planet and the CEOs of SpaceX and Blue Origin, respectively, have grand designs on the cosmos. They predict a universe where the internet is accessible from anywhere, humans are an interplanetary species, and rotating space stations host permanent residents.

But Bill Gates isn’t putting his wealth into these off-planet endeavors.

Gates, the fourth richest person alive, according to Forbes, has what he considers higher aspirations right here on Earth. While internet constellations like SpaceX’s Starlink and Amazon’s proposed Project Kuiper aim to bring for-profit fixes to the world’s pressing connectivity issues, Gates told CNN’s Becky Anderson on Wednesday that more basic problems consume his time now.

Dec 13, 2021

Crater Morphology of Primordial Black Hole Impacts

Posted by in category: cosmology

In this work we propose a novel campaign for constraining relativistically compact MACHO dark matter, such as primordial black holes (PBHs), using the moon as a detector. PBHs of about $10^{19} \textrm{ g}$ to $10^{22} \textrm{ g}$ may be sufficiently abundant to have collided with the moon in the history of the solar system. We show that the crater profiles of a PBH collision differ from traditional impactors and may be detectable in high resolution lunar surface scans now available. Any candidates may serve as sites for in situ measurements to identify high pressure phases of matter which may have formed near the PBH during the encounter. While we primarily consider PBH dark matter, the discussion generalises to the entire family of MACHO candidates with relativistic compactness.