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Archive for the ‘cosmology’ category: Page 5

Feb 22, 2024

Microscopic Origin of the Entropy of Black Holes in General Relativity

Posted by in categories: cosmology, quantum physics

In the 1970s, physicists Bekenstein and Hawking used general relativity and quantum mechanics in curved spacetime to propose that black holes behave as thermodynamic objects. They found that black holes carry an entropy described by a remarkable formula that applies for any mass, charge, angular momentum, or spacetime dimension. Here, we use new results at the interface of quantum information theory and quantum gravity to address an outstanding challenge: how to explain the microscopic origin of this formula.

In quantum mechanics, entropy measures the logarithm of the dimension of the space of microstates consistent with the macroscopic description of a system. We show that, in any theory of gravity that reduces to general relativity with matter at low energies, there are infinite families of states that have geometries identical to the black hole outside the horizon but different structures inside. We show that these states overlap quantum mechanically because of gravitational wormholes. The overlaps have a dramatic consequence: The microstates span a space whose dimension equals the exponential of the Bekenstein-Hawking entropy formula.

This explanation of black-hole entropy does not require new forms of matter and involves a novel description of all black-hole microstates as quantum superpositions of objects having geometric semiclassical descriptions. Our results also imply a macroscopic manifestation of quantum mechanics in cosmic settings: We show that one can understand long Einstein-Rosen bridges between universes as quantum superpositions of short bridges.

Feb 22, 2024

Sagittarius A*: Spinning Black Hole Shapes Spacetime into Football

Posted by in categories: cosmology, physics

“A spinning black hole is like a rocket on the launch pad,” said Dr. Biny Sebastian. “Once material gets close enough, it’s like someone has fueled the rocket and hit the ‘launch’ button.”


The center of our Milky Way Galaxy is exhibiting spinning behavior while warping the spacetime environment, according to a recent study published in the Monthly Notices of the Royal Astronomical Society. A team of international researchers led by Penn State University investigated the spinning patterns of the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A, which is located approximately 26,000 light-years from Earth, and holds the potential to help astrophysicists better understand the behavior of black holes throughout the cosmos.

“A spinning black hole is like a rocket on the launch pad,” said Dr. Biny Sebastian, who is a researcher in the Department of Physics & Astronomy at the University of Manitoba and a co-author on the study. “Once material gets close enough, it’s like someone has fueled the rocket and hit the ‘launch’ button.”

Continue reading “Sagittarius A*: Spinning Black Hole Shapes Spacetime into Football” »

Feb 22, 2024

James Webb May Soon Disprove The Big Bang Theory And Prove The Universe Is Much Older, Possibly Trillions Of Years

Posted by in category: cosmology

NASA’s James Webb Space Telescope may soon dismiss the Big Bang theory. Let’s dive into this.

Physicist Eric J. Lerner comes to the point:

Feb 22, 2024

Universe’s brightest known object and fastest-growing black hole revealed

Posted by in category: cosmology

The universe’s brightest object is a quasar in a distant galaxy that’s powered by the fastest-growing black hole ever recorded, according to a new study.

Feb 21, 2024

Scientists have found a black hole so large it eats the equivalent of one sun per day

Posted by in category: cosmology

With a mass 17 billion times larger than our sun, this black hole is the fastest-growing black hole ever recorded, Australian National University said.

Feb 21, 2024

Dark Matter May Be a Deformed Mirror Universe, Scientists Say

Posted by in categories: cosmology, particle physics

Does dark matter reside in a deformed mirror universe of our own, where rules are different and atoms failed to form?

Feb 20, 2024

To See Black Holes in Detail, She Uses ‘Echoes’ Like a Bat

Posted by in category: cosmology

Packed with mass equal to millions or billions of suns, supermassive black holes lurk at the center of nearly every galaxy.


The astrophysicist Erin Kara measures time lags in black holes’ X-ray glows, which reveal the complexity of the objects’ closest surroundings.

Continue reading “To See Black Holes in Detail, She Uses ‘Echoes’ Like a Bat” »

Feb 20, 2024

Bubble-Like ‘Stars Within Stars’ Could Explain Black Hole Weirdness

Posted by in categories: cosmology, information science, physics

Once hypothetical monsters born in a tangled nest of Einstein’s general theory of relativity, black holes are now recognized as bona fide celestial objects as real as stars, moons, and galaxies.

But make no mistake. Their engines are still as mysterious as they were when the German theoretical physicist Karl Schwarzschild first played with Einstein’s field equations and came to the conclusion that space and time could pucker up into pits of no return.

Goethe University Frankfurt physicists Daniel Jampolski and Luciano Rezzolla have gone back to step one in an attempt to make better sense of the equations that describe black holes and have come away with a solution that’s easier to picture, if no less bizarre.

Feb 20, 2024

“Beyond What’s Possible” — Webb Space Telescope Discovers Mysterious Ancient Galaxies

Posted by in category: cosmology

Our understanding of how galaxies form and the nature of dark matter could be completely upended, after new observations of a stellar population bigger than the Milky Way from more than 11 billion years ago that should not exist.

A paper published in Nature details findings using new data from the James Webb Space Telescope (JWST). The results find that a massive galaxy in the early universe – observed 11.5 billion years ago (a cosmic redshift of 3.2) – has an extremely old population of stars formed much earlier – 1.5 billion years earlier in time (a redshift of around 11). The observation upends current modeling, as not enough dark matter has built up in sufficient concentrations to seed their formation.

Swinburne University of Technology’s Distinguished Professor Karl Glazebrook led the study and the international team that used the JWST for spectroscopic observations of this massive quiescent galaxy.

Feb 20, 2024

Move Over Black Holes, ‘White Holes’ are Here to Boggle Your Mind

Posted by in categories: cosmology, mathematics, singularity

The universe, with its myriad mysteries, has long captivated our curiosity, and among its enigmatic phenomena, black holes have held a prominent place. These collapsed cores of dead stars, known for devouring everything in their vicinity, have a cosmic counterpart that challenges our understanding – the elusive ‘white holes.’

Imagine delving into the intricacies of space-time around a black hole, subtracting the collapsed star’s mass, and unveiling the mathematical description of a white hole – a massless singularity. Unlike their gravitational counterparts, black holes, where matter disappears into an event horizon, white holes defy entry. They expel matter at an astonishing rate, akin to hitting a cosmic ‘rewind’ button.

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