A machine learning method has the potential to revolutionize multi-messenger astronomy. Detecting binary neutron star mergers is a top priority for astronomers. These rare collisions between dense stellar remnants produce gravitational waves followed by bursts of light, offering a unique opportunit
Category: physics – Page 19
Study Tracks Chromium Chemistry in Irradiated Molten Salts
UPTON, N.Y. — High temperatures and ionizing radiation create extremely corrosive environments inside a nuclear reactor. To design long-lasting reactors, scientists must understand how radiation-induced chemical reactions impact structural materials. Chemists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Idaho National Laboratory recently performed experiments showing that radiation-induced reactions may help mitigate the corrosion of reactor metals in a new type of reactor cooled by molten salts. Their findings are published in the journal Physical Chemistry Chemical Physics.
“Molten salt reactors are an emerging technology for safer, scalable nuclear energy production. These advanced reactors can operate at higher, more efficient temperatures than traditional water-cooled reactor technologies while maintaining relatively ambient pressure,” explained James Wishart, a distinguished chemist at Brookhaven Lab and leader of the research.
Unlike water-cooled reactors, molten salt reactors use a coolant made entirely of positively and negatively charged ions, which remain in a liquid state only at high temperatures. It’s similar to melting table salt crystals until they flow without adding any other liquid.
Scientists discover how stellar-mass black holes emit powerful plasma jets
Black holes are fundamental to the structure of galaxies and critical in our understanding of gravity, space, and time. A stellar mass black hole is a type of black hole that forms from the gravitational collapse of a massive star at the end of its life cycle. These black holes typically have masses ranging from about 3 to 20 times the mass of our sun.
Sometimes black holes generate beams of ionized gas (plasma) that shoot outward at nearly light speed. Although discovered more than a century ago, how and why jets occur has remained a mystery, described as one of the “wonders of physics.”
Prof. Kazutaka Yamaoka from Nagoya University in Japan, along with his colleagues from the University of Toyama and other international institutes, have discovered key conditions needed for a stellar black hole to create plasma jets. Their findings, published in Publications of the Astronomical Society of Japan, show that when superheated gas material experiences a rapid shrinkage toward the black hole, jet formation occurs.
NASA’s SPHEREx Sees 100,000 Galaxies at Once, and It’s Just Getting Started — “And Wow! Just Wow!”
NASA’s new space telescope, just opened its eyes to the universe and delivered its very first images from space. Though not yet fully calibrated, the images already showcase a sweeping view filled with stars and galaxies — over 100,000 sources in each frame.
SPHEREx detects invisible infrared light and splits it into 102 hues to reveal secrets about the origins of water, galaxy distances, and even the physics of the early universe. With all systems working and its ultra-chilled detectors focused and functional, the mission promises to revolutionize cosmic surveys by mapping the entire sky multiple times and complementing more focused telescopes like Hubble and Webb.
Timeless Recursion: Nietzsche’s Eternal Return as Block Universe Prescience
Nietzsche’s intuition about time’s nature likely emerged from his engagement with contemporary scientific thought, particularly the work of Johann Friedrich Herbart and Roger Joseph Boscovich, whose atomistic theories influenced Nietzsche’s conception of force and matter (Small, 2001). Additionally, Nietzsche’s reading of Heinrich Czolbe and Otto Caspari exposed him to cyclical cosmological theories that were precursors to modern conceptions of cosmological cycles.
More compelling than these historical influences, however, is the philosophical insight Nietzsche demonstrated in recognizing that a truly eternal cosmos with finite configurations must contain repetition. This insight, while not formulated in the mathematical language of relativity, nevertheless grasped a fundamental consequence of infinite time and finite states — one that would later be encoded in physical theory.
The convergence between Nietzsche’s eternal recurrence and modern physics becomes even more significant when we recognize similar conceptions in numerous cultural and religious traditions. This suggests a perennial human intuition about time’s nature that transcends historical and cultural boundaries.
The Hubble Tension Is Becoming a Hubble Crisis
A long-simmering disagreement over the universe’s present-day expansion rate shows no signs of resolution, leaving experts increasing ly vexed.
By Anil Ananthaswamy edited by Lee Billings
Over the past decade, two very different ways of calculating the rate at which the universe is expanding have come to be at odds, a disagreement dubbed the Hubble tension, after 20th-century astronomer Edwin Hubble. Experts have speculated that this dispute might be temporary, stemming from subtle shortcomings in observations or analyses that will eventually be corrected rather than from some flawed understanding of the physics of the cosmos. Now, however, a new study that relies on an independent measure of the properties of galaxies has strengthened the case for the tension. Quite possibly, it’s here to stay.