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Archive for the ‘cosmology’ category: Page 69

Feb 24, 2024

Supernova Scavenger Hunt: Cracking the Case of Cosmic Ghost Stars

Posted by in categories: cosmology, physics

Supernovae–stellar explosions as bright as an entire galaxy–have fascinated us since time immemorial. Yet, there are more hydrogen-poor supernovae than astrophysicists can explain. Now, a new Assistant Professor at the Institute of Science and Technology Austria (ISTA) has played a pivotal role in identifying the missing precursor star population. The results, now published in Science, go back to a conversation the involved professors had many years ago as junior scientists.

The Enigma of Hydrogen-Poor Supernovae

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Feb 23, 2024

‘Quantum gravity’ could help unite quantum mechanics with general relativity at last

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

One of the primary reasons for this dilemma is that, while three of the universe’s four fundamental forces — electromagnetism, the strong nuclear force and the weak nuclear force — have quantum descriptions, there is no quantum theory of the fourth: Gravity.

Now, however, an international team has made headway in addressing this imbalance by successfully detecting a weak gravitational pull on a tiny particle using a new technique. The researchers believe this could be the first tentative step on a path that leads to a theory of “quantum gravity.”

“For a century, scientists have tried and failed to understand how gravity and quantum mechanics work together,” Tim Fuchs, team member and a scientist at the University of Southampton, said in a statement. “By understanding quantum gravity, we could solve some of the mysteries of our universe — like how it began, what happens inside black holes, or uniting all forces into one big theory.”

Feb 23, 2024

James Webb Spots Something Lurking in Wreckage of Supernova

Posted by in category: cosmology

With the help of the James Webb Space Telescope, scientists have figured out a mystery at the heart of a supernova that’s been decades in the making.

As Space.com reports, Supernova 1987A, so named for the year it was discovered here on Earth, exploded so brightly after its death that for more than 30 years, scientists weren’t sure whether it was going to form a mega-dense and compact neutron star or a black hole.

Now, an international team of scientists has begun unraveling the mystery of that long-ago explosion with the discovery of its associated neutron star, as imaged by the JWST and described in their new paper published in the journal Science.

Feb 23, 2024

Researchers Discover Cosmic Dust Storms from Type 1a Supernova

Posted by in category: cosmology

Cosmic dust—like dust on Earth—comprises groupings of molecules that have condensed and stuck together in a grain. But the exact nature of dust creation in the universe has long been a mystery. Now, however, an international team of astronomers from China, the United States, Chile, the United Kingdom, Spain, etc., has made a significant discovery by identifying a previously unknown source of dust in the universe: a Type 1a supernova interacting with gas from its surroundings.

The study was published in Nature Astronomy on Feb. 9, and was led by Prof. Wang Lingzhi from the South America Center for Astronomy of the Chinese Academy of Sciences.

Supernovae have been known to play a role in dust formation, and to date, dust formation has only been seen in core-collapse supernovae—the explosion of massive stars. Since core-collapse supernovae do not occur in elliptical galaxies, the nature of dust creation in such galaxies has remained elusive.

Feb 22, 2024

Biggest Conserver of Water in Space Contains 140 Trillion Times More Water Than Earth’s Oceans?

Posted by in category: cosmology

The water is in the form of vapor distributed around a black hole said to be 20 billion times more massive than the sun.

This reservoir of water was seen surrounded by a massive feeding black hole known as a quasar, located more than 12 billion light years away Photograph:(Agencies)

Found throughout space are extremely active and exceptionally luminous institution known as quasars. Within these galactic cores are collections of gas and dirt that have fallen into supermassive black holes and emit electromagnetic radiation. With nearly a million quasars recognized by astronomers as of August 2023, one in particular was said to be home to 140 trillion times the amount of water contained in all of Earth’s oceans.

Feb 22, 2024

A New, More Accurate Measurement for the Clumpiness of the Universe

Posted by in categories: cosmology, evolution, particle physics

Cosmologists are wrestling with an interesting question: how much clumpiness does the Universe have? There are competing but not compatible measurements of cosmic clumpiness and that introduces a “tension” between the differing measurements. It involves the amount and distribution of matter in the Universe. However, dark energy and neutrinos are also in the mix. Now, results from a recent large X-ray survey of galaxy clusters may help “ease the tension”

The eROSITA X-ray instrument orbiting beyond Earth performed an extensive sky survey of galaxy clusters to measure matter distribution (clumpiness) in the Universe. Scientists at the Max Planck Institute for Extraterrestrial Physics recently shared their analysis of its cosmologically important data.

“eROSITA has now brought cluster evolution measurement as a tool for precision cosmology to the next level,” said Dr. Esra Bulbul (MPE), the lead scientist for eROSITA’s clusters and cosmology team. “The cosmological parameters that we measure from galaxy clusters are consistent with state-of-the-art cosmic microwave background, showing that the same cosmological model holds from soon after the Big Bang to today.”

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.

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