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Category: physics – Page 20

Turbulence with a twist: New work shows fluid in a curved pipe can undergo discontinuous transition

Turbulence is everywhere, yet much about the nature of turbulence remains unknown. During the last decade, physicists have discovered how fluids in a pipe or similar geometry transition from a smooth, laminar state to a turbulent state as their speed increases.

Surprisingly, in the newly emerging consensus, the process could be understood using , not fluid mechanics, and was mathematically equivalent to the way in which water percolates down through a coffee filter.

In a new twist, UC San Diego researchers Guru K. Jayasingh and Nigel Goldenfeld have now predicted that if the pipe is sufficiently curved, the transition can become discontinuous, with the turbulent fraction undergoing a jump beyond a critical flow velocity. This jump is mathematically similar to the way in which water can suddenly and discontinuously turn into ice if cooled below the freezing temperature.

90% Chance: Physicists Predict a Black Hole Could Explode This Decade

UMass Amherst physicists believe such an explosion could occur within the next decade, potentially “revolutionizing physics and rewriting the history of the universe.” Physicists have long thought that black holes end their lives in rare explosions that occur, at most, once every 100,000 years. N

Hawking and Kerr black hole theories confirmed by gravitational wave

Scientists have confirmed two long-standing theories relating to black holes—thanks to the detection of the most clearly recorded gravitational wave signal to date.

Ten years after detecting the first gravitational wave, the LIGO-Virgo-KAGRA Collaboration has (10 Sep) announced the detection of GW250114—a ripple in spacetime which offers unprecedented insights into the nature of and the fundamental laws of physics.

The study confirms Professor Stephen Hawking’s 1971 prediction that when black holes collide, the total event horizon area of the resulting black hole is bigger than the sum of individual black holes—it cannot shrink.

Why tiny droplets stick or bounce: The physics of speed and size

When a droplet of liquid the size of a grain of icing sugar hits a water-repelling surface, like plastics or certain plant leaves, it can meet one of two fates: stick or bounce. Until now, scientists thought bouncing depended only on how repellent the surface was and how the droplet lost its impact energy. Speed, they assumed, didn’t matter.

Now, new research published in the Proceedings of the National Academy of Sciences, shows that speed is actually the deciding factor—and that only bounce within a “Goldilocks zone,” or just the right speed range.

“Bouncing only happens in a very narrow speed window,” said Jamie McLauchlan, first author of the study and Ph.D. student at the University of Bath.

First-ever complete measurement of a black-hole recoil achieved thanks to gravitational waves

A team of researchers led by the Instituto Galego de Física de Altas Enerxías (IGFAE) from the University of Santiago de Compostela (Spain) has measured for the first time the speed and direction of the recoil of a newborn black hole formed through the merger of two others. The result, published today in the journal Nature Astronomy, offers new insights into some of the most extreme events in the universe.

Gravitational waves (GWs) are ripples in the fabric of spacetime that travel away from their sources at the speed of light, encoding information about them. They provide a completely novel information channel that allows us to observe astrophysical phenomena that do not emit light—such as black hole mergers—and obtain new information about processes that do—such as supernovae or neutron-star mergers.

While Einstein predicted the existence of GWs in 1916, they are so weak that detecting them requires incredibly sensitive detectors and extremely violent astrophysical events such as black-hole mergers, supernovae or the Big Bang itself.

Unusual CO₂-rich disk detected around young star challenges planet formation models

A study led by Jenny Frediani at Stockholm University has revealed a planet-forming disk with a strikingly unusual chemical composition: an unexpectedly high abundance of carbon dioxide (CO2) in regions where Earth-like planets may one day form.

The discovery, made using the James Webb Space Telescope (JWST), challenges long-standing assumptions about the chemistry of planetary birthplaces. The study is published in Astronomy & Astrophysics.

“Unlike most nearby planet-forming disks, where dominates the inner regions, this disk is surprisingly rich in ,” says Jenny Frediani, Ph.D. student at the Department of Astronomy, Stockholm University.

Physicists achieve record precision in measuring proton-to-electron mass ratio with H₂⁺

The molecular hydrogen ion H₂⁺ is the simplest molecule. This simplicity makes it a perfect study object for physicists, as its properties—for example, its energy levels—can be calculated precisely. In turn, this enables theoretical predictions to be compared with experimental measurements to determine whether the theories reflect reality correctly.

Rethinking Physics: Scientists Discover a “Giant” New Twist on a 140-Year-Old Effect

Their results pave the way for developing advanced electronic devices that rely on nonmagnetic materials. For the first time, researchers in Japan have detected a giant anomalous Hall effect (AHE) in a material that is not magnetic. The breakthrough was made using high-quality thin films of Cd3As

Elon’s Cryptic Post Sparks Big Questions

Questions to inspire discussion.

🌐 Q: What distinguishes embedded AI from language models like ChatGPT? A: Embedded AI interacts with the real world, while LLMs (Large Language Models) primarily answer questions based on trained information.

Chip Production and Supply.

💻 Q: What are Samsung’s plans for chip production in Texas? A: Samsung’s new Texas chip plant will produce 2nm chips with 16,000 wafers/month by the end of 2024, boosted by a $16B Tesla deal.

🔧 Q: How will the Samsung-Tesla deal impact Tesla’s chip supply? A: The deal will significantly boost Tesla’s chip supply, producing 17,000 wafers per month of 2 nanometer chips reserved solely for Tesla.

AI Infrastructure and Applications.

Continue reading “Elon’s Cryptic Post Sparks Big Questions” | >

The Hofstadter butterfly: Twisted bilayer graphene reveals two distinct strongly interacting topological phases

Magic-angle twisted bilayer graphene (MATBG) is a material created by stacking two sheets of graphene onto each other, with a small twist angle of about 1.1°. At this “magic angle,” electrons move very slowly, which can lead to the emergence of highly correlated electron states.

Due to its unique properties and characteristics, MATBG has become the focus of numerous studies rooted in physics and materials science. Some physicists discovered that when an is applied to MATBG, the flat energy bands in the material transform into a fractal-like energy pattern known as a Hofstadter spectrum.

Researchers at University of Washington, Florida State University and other institutes recently carried out a study aimed at further investigating the emergence of these energy patterns in ultraclean MATBG.

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