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Category: physics – Page 35

Atmospheric reaction between Criegee intermediates and water found to be unexpectedly fast

Criegee intermediates (CIs)—highly reactive species formed when ozone reacts with alkenes in the atmosphere—play a crucial role in generating hydroxyl radicals (the atmosphere’s “cleansing agents”) and aerosols that impact climate and air quality. The syn-CH3CHOO is particularly important among these intermediates, accounting for 25%–79% of all CIs depending on the season.

Until now, scientists have believed that syn-CH3CHOO primarily disappeared through self-decomposition. However, in a study published in Nature Chemistry, a team led by Profs. Yang Xueming, Zhang Donghui, Dong Wenrui and Fu Bina from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences has uncovered a surprising new pathway: syn-CH3CHOO’s reaction with is approximately 100 times faster than previously predicted by theoretical models.

Using advanced laser techniques, the researchers experimentally measured the reaction rate between syn-CH3CHOO and water vapor, and discovered the faster reaction time. To uncover the reason behind this acceleration, they constructed a high-accuracy full-dimensional (27D) potential energy surface using the fundamental invariant-neural network approach and performed full-dimensional dynamical calculations.

Einstein predicted how gravity should work at the largest scales. And he was right, suggests new research

When Albert Einstein introduced his theory of general relativity in 1915, it changed the way we viewed the universe. His gravitational model showed how Newtonian gravity, which had dominated astronomy and physics for more than three centuries, was merely an approximation of a more subtle and elegant model.

Einstein showed us that gravity is not a mere force but is rather the foundation of cosmic structure. Gravity, Einstein said, defined the structure of space and time itself.

But in the past century, we have learned far more about the cosmos than even Einstein could have imagined. Some of our observations, such as gravitational lensing clearly confirm general relativity, but others seem to poke holes in the model. The rotational motion of galaxies doesn’t match the predictions of gravity alone, leading astronomers to introduce .

They Twisted Light on Gold — And What They Saw Blew Their Minds

Scientists in Germany have crafted “skyrmion bags” of light—complex vortex-like structures—on the surface of gold by cleverly manipulating how laser beams interact with nano-etched patterns.

This unusual feat not only adds a surprising twist to the physics of light but also hints at future technologies that could break the limits of current microscopes.

Skyrmion light bags: a new breakthrough

Living tissues may form like avalanches, a discovery that could aid new treatments

An avalanche is caused by a chain reaction of events. A vibration or a change in terrain can have a cascading and devastating impact.

A similar process may happen when living tissues are subject to being pushed or pulled, according to new research published in Nature Communications, by Northeastern University doctoral student Anh Nguyen and supervised by Northeastern physics professor Max Bi.

As , Bi and Nguyen use and mathematics to understand the mechanical processes that organisms undergo on a cellular level. With this more recent work, they have observed that when subjected to sufficient stress, tissues can “suddenly and dramatically rearrange themselves,” similar to how avalanches are formed in the wild.

Ultrasonic nanocrystal surface modification restores stainless steel’s corrosion resistance

Found in everything from kitchen appliances to sustainable energy infrastructure, stainless steels are used extensively due to their excellent corrosion (rusting) resistance. They’re an important material in many industries, including manufacturing, transportation, oil and gas, nuclear power and chemical processing.

However, stainless steels can undergo a process called sensitization when subjected to a certain range of high temperatures—like during welding—and this substantially deteriorates their resistance. Left unchecked, corrosion can lead to cracking and structural failure.

“This is a major problem for stainless steels,” says Kumar Sridharan, a professor of nuclear engineering and engineering physics and materials science and engineering at the University of Wisconsin–Madison. “When gets corroded, components need to be replaced or remediated. This is an expensive process and causes extended downtime in industry.”

New framework suggests stars dissolve into neutrons to forge heavy elements

Understanding the origin of heavy elements on the periodic table is one of the most challenging open problems in all of physics. In the search for conditions suitable for these elements via “nucleosynthesis,” a Los Alamos National Laboratory-led team is going where no researchers have gone before: the gamma-ray burst jet and surrounding cocoon emerging from collapsed stars.

As proposed in an article in The Astrophysical Journal, photons produced deep in the jet could dissolve the outer layers of a star into neutrons, causing a series of physical processes that result in the formation of heavy elements.

“The creation of heavy elements such as uranium and plutonium necessitates extreme conditions,” said Matthew Mumpower, physicist at Los Alamos. “There are only a few viable yet rare scenarios in the cosmos where these elements can form, and all such locations need a copious amount of neutrons. We propose a new phenomenon where those neutrons don’t pre-exist but are produced dynamically in the star.”

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