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Archive for the ‘cosmology’ category

Oct 12, 2024

Why the black hole information paradox still hasn’t been solved

Posted by in categories: cosmology, quantum physics

But you might notice that something is missing: this radiation doesn’t seem to encode, in any way, knowledge of the information that went into the creation of the black hole in the first place. Somewhere along the way, information was destroyed. That’s the key puzzle behind the black hole information paradox. No one seriously disputes the initial setup of the puzzle: that information exists, and that the information (and entropy) does in fact go into the black hole both when it’s first created and also as it grows. What is up for debate, and what in fact is the big question behind the information paradox, is whether that information comes back out again or not.

The way we calculate what comes out of a black hole via Hawking radiation, despite the fact that Hawking radiation has been around for a full half century as of 2024, hasn’t changed all that much over the past 50 years. What we do is assume the curvature of space from general relativity: the fabric of space is curved by the presence of matter and energy, and general relativity tells us exactly by how much.

We then perform our quantum field theory calculations in that curved space, detailing the radiation that comes out as a result. That’s where we learn that the radiation has the temperature, spectrum, entropy, and other properties we know that it possesses, including the fact that it doesn’t appear to encode that initial information when the radiation comes out.

Oct 11, 2024

Transcendence: Enlightenment, Singularity & The Fermi Paradox

Posted by in categories: cosmology, existential risks, media & arts, singularity

Many seek a path to enlightenment through study and meditation, but what does science tell us about transcendence? And could entire civilizations seek to leave this reality behind?

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Oct 11, 2024

Magnifying Deep Space Through the ‘Carousel Lens’

Posted by in categories: cosmology, physics

A newly discovered cluster-scale strong gravitational lens, with a rare alignment of seven background lensed galaxies, provides a unique opportunity to study cosmology.

In a rare and extraordinary discovery, researchers have identified a unique configuration of galaxies that form the most exquisitely aligned gravitational lens found to date. The Carousel Lens is a massive cluster-scale gravitational lens system that will enable researchers to delve deeper into the mysteries of the cosmos, including dark matter and dark energy.

“This is an amazingly lucky ‘galactic line-up’ — a chance alignment of multiple galaxies across a line-of-sight spanning most of the observable universe,” said David Schlegel, a co-author of the study and a senior scientist in Berkeley Lab’s Physics Division. “Finding one such alignment is a needle in the haystack. Finding all of these is like eight needles precisely lined up inside that haystack.”

Oct 10, 2024

The universe is significantly older than previously thought

Posted by in category: cosmology

In a groundbreaking discovery, the James Webb Space Telescope (JWST) has presented data that directly challenges our current understanding of the universe. For years, cosmologists have pegged the universe’s age at approximately 13.8 billion years. Yet, the new JWST findings suggest that this may be a vast underestimation. But how has one telescope managed to disrupt such a long-held belief?

The universe’s secrets are vast, but none has been as puzzling as the presence of ‘impossible early galaxies’—so named due to their peculiar formation periods.

Continue reading “The universe is significantly older than previously thought” »

Oct 9, 2024

Physicists Simulated a Black Hole in The Lab, And Then It Began to Glow

Posted by in categories: cosmology, mathematics, particle physics, quantum physics

A black hole analog could tell us a thing or two about an elusive radiation theoretically emitted by the real thing.

Using a chain of atoms in single-file to simulate the event horizon of a black hole, a team of physicists in 2022 observed the equivalent of what we call Hawking radiation – particles born from disturbances in the quantum fluctuations caused by the black hole’s break in spacetime.

This, they say, could help resolve the tension between two currently irreconcilable frameworks for describing the Universe: the general theory of relativity, which describes the behavior of gravity as a continuous field known as spacetime; and quantum mechanics, which describes the behavior of discrete particles using the mathematics of probability.

Oct 9, 2024

For the first time ever, scientists find that gravity can exist without mass

Posted by in category: cosmology

Dark matter, a mysterious substance thought to make up most of the universe’s mass, has puzzled scientists for nearly a century. First proposed by Dutch astronomer Jan Oort in 1932 to explain the “missing mass” needed for galaxies to stay together, it remains undetected despite decades of research. However, a recent study by Dr. Richard Lieu at The…

Oct 9, 2024

Twisted Black Hole Accretion Disks Revealed by XRISM’s Cutting-Edge X-Ray Vision

Posted by in categories: cosmology, satellites

XRISM is transforming our understanding of supermassive black holes and their galactic neighborhoods, providing high-resolution X-ray spectra that reveal complex structures like twisted accretion disks.

This groundbreaking international space mission, a collaboration between JAXA, NASA, and ESA, is only beginning to unveil the intricate details of black holes and their impact on galaxy formation, with early data already confirming long-held hypotheses.

Initial data from an international space mission is confirming decades of hypotheses about the galactic environments surrounding supermassive black holes. Yet, even more thrilling is the satellite behind this data—the X-Ray Imaging and Spectroscopy Mission (XRISM)—is just getting started providing such unparalleled insights.

Oct 9, 2024

Detecting Planck-scale dark matter by leveraging quantum interference

Posted by in categories: cosmology, quantum physics

While various studies have hinted at the existence of dark matter, its nature, composition and underlying physics remain poorly understood.

Oct 8, 2024

Our Galaxy Appears To Be Part Of Structure So Large It Challenges Our Models Of Cosmology

Posted by in category: cosmology

The tiny red dot is us.

Oct 8, 2024

Astronomers Detect Black Hole ‘Starving’ its Host Galaxy to Death

Posted by in category: cosmology

Astronomers have used the NASA/ESA James Webb Space Telescope to confirm that supermassive black holes can starve their host galaxies of the fuel they need to form new stars. The results are reported in the journal Nature Astronomy.

The international team, co-led by the University of Cambridge, used Webb to observe a galaxy roughly the size of the Milky Way in the early universe, about two billion years after the Big Bang. Like most large galaxies, it has a supermassive black hole at its center. However, this galaxy is essentially ‘dead’: it has mostly stopped forming new stars.

“Based on earlier observations, we knew this galaxy was in a quenched state: it’s not forming many stars given its size, and we expect there is a link between the black hole and the end of star formation,” said co-lead author Dr. Francesco D’Eugenio from Cambridge’s Kavli Institute for Cosmology.

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