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Archive for the ‘cosmology’ category: Page 22

Jul 24, 2024

A star transformed into a black hole instead of exploding

Posted by in category: cosmology

When a large star runs out of fuel, its core collapses into a dense object, ejecting the remaining gas outward in an event known as a supernova. What’s left are largely neutron stars and black holes. And now Hubble appears to have observed a supernova blink out, implying that it captured the instant a black hole took over.

What makes this occurrence unique is that the formation of a black hole was not foreseen. Normally, when a star of this size reaches the end of its life, it explodes in a massive event called a supernova. Instead, it appears that this star chose to go out quietly.

Jul 24, 2024

Primordial black holes can only explain a fraction of dark matter, research suggests

Posted by in category: cosmology

What is dark matter? That question is prominent in discussions about the nature of the universe. There are many proposed explanations for dark matter, both within the Standard Model and outside of it.

Jul 24, 2024

Tiny Bright Objects discovered at Dawn of Universe baffle scientists

Posted by in categories: cosmology, evolution

A recent discovery by NASA’s James Webb Space Telescope (JWST) confirmed that luminous, very red objects previously detected in the early universe upend conventional thinking about the origins and evolution of galaxies and their supermassive black holes.

An international team, led by Penn State researchers, using the NIRSpec instrument aboard JWST as part of the RUBIES survey identified three mysterious objects in the early universe, about 600–800 million years after the Big Bang, when the universe was only 5% of its current age. They announced the discovery today June 27 in Astrophysical Journal Letters.

The team studied spectral measurements, or intensity of different wavelengths of light emitted from the objects. Their analysis found signatures of “old” stars, hundreds of millions of years old, far older than expected in a young universe.

Jul 24, 2024

SAQFT: Algebraic quantum field theory for elementary and composite particles

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

Quantum field theory (QFT) was a crucial step in our understanding of the fundamental nature of the Universe. In its current form, however, it is poorly suited for describing composite particles, made up of multiple interacting elementary particles. Today, QFT for hadrons has been largely replaced with quantum chromodynamics, but this new framework still leaves many gaps in our understanding, particularly surrounding the nature of strong nuclear force and the origins of dark matter and dark energy. Through a new algebraic formulation of QFT, Dr Abdulaziz Alhaidari at the Saudi Center for Theoretical Physics hopes that these issues could finally be addressed.

The emergence of quantum field theory (QFT) was one of the most important developments in modern physics. By combining the theories of special relativity, quantum mechanics, and the interaction of matter via classical field equations, it provides robust explanations for many fundamental phenomena, including interactions between charged particles via the exchange of photons.

Still, QFT in its current form is far from flawless. Among its limitations is its inability to produce a precise description of composite particles such as hadrons, which are made up of multiple interacting elementary particles that are confined (cannot be observed in isolation). Since these particles possess an internal structure, the nature of these interactions becomes far more difficult to define mathematically, stretching the descriptive abilities of QFT beyond its limits.

Jul 24, 2024

Supermassive black holes provide ‘hearts and lungs’ that help galaxies live longer

Posted by in category: cosmology

Can black hole jets suffer from cosmic hypertension?

Jul 24, 2024

There are hints that dark energy may be getting weaker

Posted by in category: cosmology

The standard model of cosmology says that the strength of dark energy should be constant, but tentative hints are emerging that it may have weakened recently.

By Leah Crane

Jul 24, 2024

‘Immortal’ stars at the Milky Way’s center may have found an endless energy source, study suggests

Posted by in category: cosmology

Strange stars clustered near the Milky Way’s center are much younger than theory predicts is possible. New research suggests their youth could actually be eternal — and fueled by annihilating dark matter.

Jul 23, 2024

High-energy collision study reveals new insights into quark-gluon plasma

Posted by in categories: cosmology, particle physics

In high-energy physics, researchers have unveiled how high-energy partons lose energy in nucleus-nucleus collisions, an essential process in studying quark-gluon plasma (QGP). This finding could enhance our knowledge of the early universe moments after the Big Bang.

Jul 23, 2024

Solving Quantum Mysteries: Physicists Confirm Entropy Rule for Entanglement

Posted by in categories: computing, cosmology, quantum physics

New research has established a reversible framework for quantum entanglement, aligning it with the principles of thermodynamics and paving the way for improved manipulation and understanding of quantum resources.

Bartosz Regula from the RIKEN Center for Quantum Computing and Ludovico Lami from the University of Amsterdam have demonstrated through probabilistic calculations the existence of an “entropy” rule for quantum entanglement. This discovery could enhance our understanding of quantum entanglement, a crucial resource underpinning the potential of future quantum computers. Although quantum entanglement has been a research focus in quantum information science for decades, optimal methods for its effective utilization remain largely unknown.

The second law of thermodynamics, which says that a system can never move to a state with lower “entropy”, or order, is one of the most fundamental laws of nature and lies at the very heart of physics. It is what creates the “arrow of time,” and tells us the remarkable fact that the dynamics of general physical systems, even extremely complex ones such as gases or black holes, are encapsulated by a single function, its “entropy.”

Jul 23, 2024

Astronomers spotted a red supergiant just before it exploded in a massive supernova

Posted by in categories: cosmology, innovation

It was discovered just 130 days before exploding using two telescopes in Hawaii, allowing a team of experts to investigate it before it exploded in a massive supernova.

“This is a breakthrough in our understanding of what massive stars do moments before they die,” said Dr. Wynn Jacobson-Galán, the study’s lead author.

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