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Archive for the ‘cosmology’ category: Page 259

Jan 16, 2021

Study investigates emission from a distant red quasar

Posted by in categories: cosmology, evolution, existential risks

Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, an international team of astronomers has performed observations of HSC J120505.09−000027.9—the most distant red quasar so far detected and found that it showcases an extended emission of ionized carbon. The finding is reported in a paper published January 4 on arXiv.org.

Quasars, or quasi– (QSOs), are extremely luminous active galactic nuclei (AGN) containing supermassive central black holes with accretion disks. Their redshifts are measured from the strong spectral lines that dominate their visible and . Some QSOs are dust-reddened, hence dubbed red quasars. These objects have a non-negligible amount of dust extinction, but are not completely obscured.

Astronomers are especially interested in studying high-redshift quasars (at redshift higher than 5.0) as they are the most luminous and most distant compact objects in the observable universe. Spectra of such QSOs can be used to estimate the mass of supermassive black holes that constrain the evolution and formation models of quasars. Therefore, could serve as a powerful tool to probe the early universe.

Jan 15, 2021

X-rays surrounding ‘Magnificent 7’ may be traces of sought-after particle

Posted by in categories: cosmology, particle physics

A new study, led by a theoretical physicist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), suggests that never-before-observed particles called axions may be the source of unexplained, high-energy X-ray emissions surrounding a group of neutron stars.

First theorized in the 1970s as part of a solution to a fundamental particle physics problem, axions are expected to be produced at the core of stars, and to convert into particles of light, called photons, in the presence of a magnetic field.

Axions may also make up —the mysterious stuff that accounts for an estimated 85 percent of the total mass of the universe, yet we have so far only seen its gravitational effects on ordinary matter. Even if the X-ray excess turns out not to be axions or dark matter, it could still reveal new physics.

Jan 15, 2021

Endless Versions of You in Endless Parallel Universes? A Growing Number of Physicists Embrace the Idea

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

Circa 2019


Conventionally speaking, there is a single physicist named Sean Carroll at Caltech, busily puzzling over the nature of the quantum world. In the theoretical sense, though, he may be one of a multitude, each existing in its own world. And there’s nothing unique about him: Every person, rock, and particle in the universe participates in an endlessly branching reality, Carroll argues, splitting into alternate versions whenever an event occurs that has multiple possible outcomes.

He is well aware that this idea sounds like something from a science fiction movie (and it doesn’t help that he was an advisor on Avengers: Endgame). But these days, a growing number of his colleagues take the idea of multiple worlds seriously. In his new book, Something Deeply Hidden, Carroll proposes that the “Many Worlds Interpretation” is not only a reasonable way to make sense of quantum mechanics, it is the most reasonable way to do so.

Continue reading “Endless Versions of You in Endless Parallel Universes? A Growing Number of Physicists Embrace the Idea” »

Jan 13, 2021

From supernova to something much more intriguing at the core of galaxy 253–3

Posted by in category: cosmology

On 14 November 2014, a bright flash flagged the All Sky Automated Survey for Supernovae, or ASAS-SN — a global network of 20 telescopes managed at Ohio State University in the U.S. The flash originated in galaxy ESO 253–3, located 570 million light-years away.

The sudden burst of energy was examined by astronomers and categorized as a likely supernova and assigned the event designation ASASSN-14ko. Six years later, Anna Payne, a NASA Graduate Fellow at the University of Hawai’i at Mānoa, discovered it was something much different.

Continue reading “From supernova to something much more intriguing at the core of galaxy 253-3” »

Jan 13, 2021

Our Improbable Existence Is No Evidence for a Multiverse

Posted by in category: cosmology

Experts in probability have spotted a logical flaw in theorists’ reasoning.

Jan 12, 2021

Dark Energy, Dark Matter

Posted by in category: cosmology

Science Mission Directorate


What is dark energy? More is unknown than is known — we know how much there is, and we know some of its properties; other than that, dark energy is a mystery — but an important one. Roughly 70% of the Universe is made of dark energy. Dark matter makes up about 25%. The rest — everything on Earth, everything ever observed with all of our instruments, all normal matter adds up to less than 5% of the Universe. Then again, maybe it shouldn’t be called “normal” matter since it is a small fraction of the Universe!

Jan 10, 2021

There’s no way to Measure the Speed of Light in a Single Direction

Posted by in categories: cosmology, materials

A new study shows that not even cosmology can verify Einstein’s assumption about the speed of light.


Special relativity is one of the most strongly validated theories humanity has ever devised. It is central to everything from space travel and GPS to our electrical power grid. Central to relativity is the fact that the speed of light in a vacuum is an absolute constant. The problem is, that fact has never been proven.

When Einstein proposed the theory of relativity, it was to explain why light always had the same speed. In the late 1800s it was thought that since light travels as a wave it must be carried by some kind of invisible material known as the luminiferous aether. The reasoning was that waves require a medium, such as sound in air or water waves in water. But if the aether exists, then the observed speed of light must change as the Earth moves through the aether. But measurements to observe aether drift came up null. The speed of light appeared to be constant.

Continue reading “There’s no way to Measure the Speed of Light in a Single Direction” »

Jan 9, 2021

Deepening Astronomical Mystery: On the Hunt for a Missing Giant Black Hole

Posted by in category: cosmology

Astronomers are searching for signs of a supermassive black hole in the galaxy cluster Abell 2261. Nearly all large galaxies contain central black holes, and the galaxy in the middle of Abell 2261 is expected to contain a particularly massive one.

Jan 9, 2021

Black holes leak energy when they eat plasma near the event horizon

Posted by in categories: cosmology, particle physics

When magnetic fields around a black hole reconnect, they can slow down plasma particles near the event horizon, which cause the black hole to lose energy when it swallows them.

Jan 9, 2021

Scientists Think the Multiverse Might Be the Key to Explaining Dark Matter

Posted by in category: cosmology

A new study theorizes that black holes made of collapsed universes originate dark matter, and our own universe may look like a black hole to outsiders.