Archive for the ‘physics’ category: Page 8

Jan 9, 2024

China launches “lobster eye” Einstein Probe to unveil mysteries of X-ray universe

Posted by in categories: cosmology, physics

HELSINKI — China launched its Einstein Probe early Tuesday to detect X-ray emissions from violent, fleeting cosmic phenomena using novel lobster eye-inspired optics.

A Long March 2C rocket lifted off from Xichang Satellite Launch Center in southwestern China at 2:03 a.m. (0703 UTC), Jan. 9. The China Aerospace Science and Technology Corp. (CASC) confirmed launch success within the hour.

The Einstein Probe (EP) is part of growing Chinese strategic space science efforts. The spacecraft will spend at least three years observing distant, violent interactions such as tidal disruption events—in which stars are pulled apart by supermassive black holes—supernovae, and detect and localize the high-energy, electromagnetic counterparts to gravitational wave events.

Jan 9, 2024

Altermagnetism Then and Now

Posted by in category: physics

Recent theoretical work has identified the possibility of a new and fundamental form of magnetism.

Collinear magnetism, where magnetic moments of all ions are parallel or antiparallel to each other, is a century-old concept in condensed-matter physics. In the past two decades, researchers began exploring the exotic world of noncollinear magnets, which include spin spirals, skyrmions, spin ices, and more. But more recently a fundamentally new form of collinear magnetism has emerged: altermagnetism. Like ferromagnetism, it breaks time-reversal symmetry and harbors anomalous transport properties, such as the anomalous Hall effect and magneto-optics. Like antiferromagnetism, it has, by symmetry, no net magnetization. The phenomenon was identified between 2019 and 2021 by four different groups [1–4]. In 2022, Libor Šmejkal of Johannes Gutenberg University Mainz in Germany and colleagues named it altermagnetism [5]. Despite its youth, altermagnetism is already proving a fertile field for theory and for proposed applications.

Jan 9, 2024

Study explores the properties of a faint tidal disruption event

Posted by in categories: cosmology, evolution, physics

Using a spectral synthesis code designed to simulate conditions in interstellar matter, astronomers have explored a faint tidal disruption event (TDE) designated iPTF16fnl. Results of the study, published Dec. 29 on the pre-print server arXiv, deliver important insights into the properties of this TDE.

TDEs are astronomical phenomena that occur when a star passes close enough to a and is pulled apart by the black hole’s tidal forces, causing the process of disruption. Such tidally-disrupted stellar debris starts raining down on the black hole and radiation emerges from the innermost region of accreting debris, which is an indicator of the presence of a TDE. All in all, the debris stream-stream collision causes an energy dissipation, which may lead to the formation of an accretion disk.

Therefore, TDEs are perceived by as potentially important probes of strong gravity and accretion physics, providing answers about the formation and evolution of supermassive .

Jan 9, 2024

Scientists invent ultrathin optical crystal for next-generation laser tech

Posted by in categories: energy, physics

A team of Chinese researchers used a novel theory to invent a new type of ultrathin optical crystal with high energy efficiency, laying the foundation for next-generation laser technology.

Prof. Wang Enge from the School of Physics, Peking University, recently told Xinhua that the Twist Boron Nitride (TBN) made by the team, with a micron-level thickness, is the thinnest optical crystal currently known in the world. Compared with traditional crystals of the same thickness, its is raised by 100 to 10,000 times.

Wang, also an academician of the Chinese Academy of Sciences, said this achievement is an original innovation by China in the theory of optical crystals and has created a new field of making optical crystals with two-dimensional thin-film materials of light elements.

Jan 8, 2024

Revealing the True Colors of Neptune and Uranus: A Breakthrough Study

Posted by in categories: physics, space

“The misperception of Neptune’s color, as well as the unusual color changes of Uranus, have bedeviled us for decades. This comprehensive study should finally put both issues to rest,” said Dr. Heidi Hammel.

In space, not everything is how it seems, and this might be the case with Uranus and Neptune, as a study scheduled to be published in February 2024 in the Monthly Notices of the Royal Astronomical Society examines how the colors of the two gas giants might be more similar that what NASA’s Voyager 2 spacecraft imaged in 1986 and 1989, respectively, as it flew past the gas giants during its mission. Originally, Voyager 2 imaged Uranus to exhibit a greenish-type color while Neptune appeared to be a strong blue, and this new study holds the potential to help scientists better understand how to estimate the true colors of planets throughout the cosmos.

“Although the familiar Voyager 2 images of Uranus were published in a form closer to ‘true’ color, those of Neptune were, in fact, stretched and enhanced, and therefore made artificially too blue,” said Dr. Patrick Irwin, who is a Professor of Planetary Physics at the University of Oxford and lead author of the study. “Even though the artificially-saturated color was known at the time amongst planetary scientists – and the images were released with captions explaining it – that distinction had become lost over time.”

Continue reading “Revealing the True Colors of Neptune and Uranus: A Breakthrough Study” »

Jan 8, 2024

Scientists flip around gravitational-wave data analysis: Have LIGO and Virgo detected a merger of dark-matter stars?

Posted by in categories: cosmology, physics

Thanks to the LIGO and Virgo detectors, researchers now regularly observe ripples in spacetime known as gravitational waves, which are caused by catastrophic cosmic events such as black-hole mergers, star explosions, or the big bang itself.

Gravitational waves are ripples in the fabric of spacetime that travel at the speed of light. These are produced in some of the most violent events in the universe, such as black-hole mergers, supernovae, or the Big Bang itself. Since their first detection in 2015, and after three observing runs, the Advanced LIGO and Virgo detectors have detected around 100 such waves.

Thanks to these observations, we are starting to unveil the black-hole population of our universe, study gravity in its most extreme regime and even determine the formation of elements like gold or platinum during the merger of neutron stars.

Continue reading “Scientists flip around gravitational-wave data analysis: Have LIGO and Virgo detected a merger of dark-matter stars?” »

Jan 7, 2024

“Zoo Hypothesis Or Nothing”: New Unnerving Answer To The Fermi Paradox

Posted by in categories: existential risks, physics

A team of physicists think we are close to solving the Fermi Paradox.

Jan 7, 2024

Defying Gravity: Scientists Solve Mystery of Magnetic Hovering Beyond Classical Physics

Posted by in category: physics

Scientists from the Technical University of Denmark (DTU) have confirmed the underlying physics of a newly discovered phenomenon of magnet levitation. In 2021, a scientist from Turkey published a research paper detailing an experiment where a magnet was attached to a motor, causing it to rotate rapidly. When this setup was brought near a second magnet, the second magnet began to rotate and suddenly hovered in a fixed position a few centimeters away.

Jan 6, 2024

Metal-organic frameworks study unravels mechanism for capturing water from air

Posted by in categories: chemistry, physics, sustainability

Researchers from the Helmholtz-Zentrum Dresden-Rossendorf and Dresden University of Technology have unraveled the water adsorption mechanism in certain microporous materials—so-called hierarchical metal-organic frameworks (MOFs)—while probing them on the atomic scale.

Discovered only about 25 years ago, their special properties quickly led to a reputation as “miracle materials”—which, as it turned out, can even harvest water from air. The researchers describe how the material achieves this in ACS Applied Materials & Interfaces.

“These very special materials are highly porous solids made of metals or metal-oxygen clusters which are connected in a modular way by pillars of organic chemicals. This 3D arrangement leads to networks of cavities reminiscent of the pores of a kitchen sponge. It is precisely these cavities that we are interested in,” says Dr. Ahmed Attallah of HZDR´s Institute of Radiation Physics.

Jan 5, 2024

Magnetic Mystique: A Deeper Look at Massive Star Systems

Posted by in categories: cosmology, evolution, physics

A new study reveals that magnetic fields are common in star systems with large blue stars, challenging prior beliefs and providing insights into the evolution and explosive nature of these massive stars.

Astronomers from the Leibniz Institute for Astrophysics Potsdam (AIP), the European Southern Observatory (ESO), and the MIT Kavli Institute and Department of Physics have discovered that magnetic fields in multiple star systems with at least one giant, hot blue star, are much more common than previously thought by scientists. The results significantly improve the understanding of massive stars and their role as progenitors of supernova explosions.

Characteristics of O-type Stars.

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