Archive for the ‘cosmology’ category: Page 111
Sep 9, 2021
The Big Bang and the genetic code
Posted by Quinn Sena in categories: chemistry, cosmology, genetics, humor, particle physics
Circa 2000
A 1940 paper by Gamow and Mario Schoenberg was the first in a subject we now call particle astrophysics. The two authors presciently speculated that neutrinos could play a role in the cooling of massive collapsing stars. They named the neutrino reaction the Urca process, after a well known Rio de Janeiro casino. This name might seem a strange choice, but not to Gamow, a legendary prankster who once submitted a paper to Nature in which he suggested that the Coriolis force might account for his observation that cows chewed clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
In the 1940s Gamow began to attack, with his colleague Ralph Alpher, the problem of the origin of the chemical elements. Their first paper on the subject appeared in a 1948 issue of the Physical Review. At the last minute Gamow, liking the sound of ‘alpha, beta, gamma’, added his old friend Hans Bethe as middle author in absentia (Bethe went along with the joke, but the editors did not). Gamow and Alpher, with Robert Herman, then pursued the idea of an extremely hot neutron-dominated environment. They envisioned the neutrons decaying into protons, electrons and anti-neutrinos and, when the universe had cooled sufficiently, the neutrons and protons assembling heavier nuclei. They even estimated the photon background that would be necessary to account for nuclear abundances, suggesting a residual five-degree background radiation.
Sep 9, 2021
Black holes just got much more complicated thanks to quantum pressure
Posted by Genevieve Klien in categories: cosmology, quantum physics
Black holes were once thought not to have pressure, but a new set of quantum calculations has found that they may have some at their edges, which was completely unexpected.
Sep 9, 2021
Super-precise clock tech wins $3 million physics Breakthrough Prize
Posted by Genevieve Klien in categories: cosmology, physics
Optical lattice clocks could help scientists detect gravitational waves, hunt for dark matter and much more.
Two physicists just snagged $3 million for helping develop a super-precise clock that could allow scientists to study and explore the universe like never before.
Sep 8, 2021
New theory for detecting light in the darkness of a vacuum
Posted by Quinn Sena in categories: cosmology, particle physics
Black holes are regions of space-time with huge amounts of gravity. Scientists originally thought that nothing could escape the boundaries of these massive objects, including light.
The precise nature of black holes has been challenged ever since Albert Einstein’s general theory of relativity gave rise to the possibility of their existence. Among the most famous findings was English physicist Stephen Hawking’s prediction that some particles are actually emitted at the edge of a black hole.
Physicists have also explored the workings of vacuums. In the early 1970s, as Hawking was describing how light can escape a black hole’s gravitational pull, Canadian physicist William Unruh proposed that a photodetector accelerated fast enough could “see” light in a vacuum.
Sep 7, 2021
A Black Hole Triggers a Premature Supernova — First Observation of a Brand-New Kind of Supernova
Posted by Genevieve Klien in category: cosmology
The first observation of a brand-new kind of supernova had been predicted by theorists but never before confirmed.
In 2,017 a particularly luminous and unusual source of radio waves was discovered in data taken by the Very Large Array (VLA) Sky Survey, a project that scans the night sky in radio wavelengths. Now, led by Caltech graduate student Dillon Dong (MS ’18), a team of astronomers has established that the bright radio flare was caused by a black hole or neutron star crashing into its companion star in a never-before-seen process.
“Massive stars usually explode as supernovae when they run out of nuclear fuel,” says Gregg Hallinan, professor of astronomy at Caltech. “But in this case, an invading black hole or neutron star has prematurely triggered its companion star to explode.” This is the first time a merger-triggered supernova has ever been confirmed.
Sep 7, 2021
Near-Earth supermassive black hole hidden in tendrils photographed
Posted by Quinn Sena in category: cosmology
A phenomenal new image captured with the Dark Energy Camera shows a near-Earth galaxy with a hidden supermassive black hole.
Sep 7, 2021
Black hole made in the lab shows signs of quantum entanglement
Posted by Quinn Sena in categories: cosmology, quantum physics
Circa 2020
Efforts to study black holes in the lab with versions that trap sound instead of light may have revealed a key prediction made by Stephen Hawking.
Sep 5, 2021
We may finally know where high-energy cosmic rays come from
Posted by Atanas Atanasov in categories: chemistry, cosmology, space travel
High-energy cosmic rays have proven elusive… but we may have found their source.
Thanks to new research led by the University of Nagoya, scientists have quantified the number of cosmic rays produced in a supernova remnant for the first time. This research has helped resolve a 100-year mystery and is a major step towards determining precisely where cosmic rays come from.
While scientists theorize that cosmic rays originate from many sources — our Sun, supernovae, gamma-ray bursts (GRBs), and active galactic nuclei (sometimes called quasars) — their exact origin has been a mystery since they were first discovered in 1912. Similarly, astronomers have theorized that supernova remnants (the after-effects of supernova explosions) are responsible for accelerating them to nearly the speed of light.
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Sep 5, 2021
New Evidence against the Standard Model of Cosmology
Posted by Alan Jurisson in categories: cosmology, physics
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This video’s topic is close to my own research, cosmology. The current standard model of cosmology rests on the “cosmological principle” — the idea that the universe looks, on the average, the same everywhere. Alas, it doesn’t look good for the cosmological principle. Just what does the evidence say and, if it holds up, what does this mean? At the end of this video, you’ll know.
Continue reading “New Evidence against the Standard Model of Cosmology” »