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Physicists observe image rotation in plasma

Light sometimes appears to be “dragged” by the motion of the medium through which it is traveling. This phenomenon, referred to as “light dragging,” is typically imperceptible when light is traveling in most widely available materials, as the movement is significantly slower than the speed of light. So far, it has thus proved difficult to observe in experimental settings.

Researchers at the University of Toulouse, University of California-Los Angeles (UCLA), University of Paris-Saclay and Princeton University recently observed a specific type of dragging known as image rotation in a plasma-based system.

Their observation, outlined in a paper published in Physical Review Letters, was made using magnetohydrodynamic (MHD) that propagate in a magnetized plasma, known as Alfvén waves.

Thermodiffusion method offers greener extraction of valuable materials from brine deposits

A simple and cost-effective method developed by scientists at The Australian National University (ANU) could make the process of extracting valuable resources from brine deposits more environmentally friendly. The research is published in Nature Water.

Brine mining is important for lithium extraction—a critical component for battery manufacturing—with a significant portion of global lithium production coming from continental brine deposits.

In 2024, ANU researchers developed the world’s first thermal desalination method, where water remains in the throughout the entire process. They have now successfully applied this method to brine concentration.

Solid catalyst breaks the rules: Oxygen evolution steps can happen simultaneously

Oxygen evolution is considered one of the most energy-intensive steps in water electrolysis and is therefore a key factor for more efficient green hydrogen production. Modeling of the reaction mechanisms has so far been based on the assumption that the elementary steps take place sequentially and not in a concerted manner.

A team led by Prof. Dr. Kai S. Exner from the University of Duisburg-Essen has now shown that this assumption is not always correct. The results, published in Nature Communications, open up new possibilities for improving solid catalysts for energy conversion and storage applications.

There are two basic types of catalysis: homogeneous catalysts have the same physical state as the substances being converted (e.g., they all are liquid), while are in a different phase, for example a solid that reacts with liquids or gases. For a reaction to take place on the surface of a solid catalyst, the starting materials (reactants) must attach to its surface (adsorption) and then dissolve again after the reaction has taken place (desorption).

Light and heavy electrons cooperate in magic-angle superconductors

Electrons play many roles in solid materials. When they are weakly bound and able to travel—i.e., mobile—they can enable electrical conduction. When they are bound, or “heavy,” they can act as insulators. However, in certain solid materials, this behavior can be markedly different, raising questions about how these different types of electrons interact.

In a study just published in Nature Physics, researchers working with Professor of Physics and Applied Physics Amir Yacoby at Harvard examined the interplay between both types of electrons in this material, shedding new on how they may help form novel quantum states.

“Before our work, people could only ask ‘What is the overall ground state?’” said Andrew T. Pierce, one of the paper’s lead authors. Pierce, currently a fellow at Cornell University, was a graduate student in Yacoby’s lab when they began to study this question. What wasn’t clear was the true nature of these different states and how the separate light and heavy electrons joined forces to form them.

Super-resolution imaging reveals the first step of planet formation after star birth

Identifying the formation period of planetary systems, such as our solar system, could be the beginning of the journey to discover the origin of life. The key to this is the unique substructures found in protoplanetary disks—the sites of planet formation.

A protoplanetary disk is composed of low-temperature molecular gas and dust, surrounding a protostar. If a planet exists in the disk, its gravity will gather or eject materials within the disk, forming characteristic substructures such as rings or spirals. In other words, various disk substructures can be interpreted as “messages” from the forming planets. To study these substructures in detail, high-resolution radio observations with ALMA are required.

Numerous ALMA observations of protoplanetary disks (or circumstellar disks) have been conducted so far. In particular, two ALMA large programs, DSHARP and eDisk, have revealed the detailed distribution of dust in protoplanetary disks through high-resolution observations.

Senate Votes to Allow State A.I. Laws, a Blow to Tech Companies

There are no federal laws regulating A.I. but states have enacted dozens of laws that strengthen consumer privacy, ban A.I.-generated child sexual abuse material and outlaw deepfake videos of political candidates. All but a handful of states have some laws regulating artificial intelligence in place. It is an area of deep interest: All 50 have introduced bills in the past year tied to the issue.

The Senate’s provision, introduced in the Senate by Senator Ted Cruz, Republican of Texas, sparked intense criticism by state attorneys general, child safety groups and consumer advocates who warned the amendment would give A.I. companies a clear runway to develop unproven and potentially dangerous technologies.

Breaking Ohm’s law: Nonlinear currents emerge in symmetry-broken materials

In a review just published in Nature Materials, researchers take aim at the oldest principle in electronics: Ohm’s law.

Their article, “Nonlinear transport in non-centrosymmetric systems,” brings together rapidly growing evidence that, when a material lacks inversion symmetry, the familiar linear relation between current and voltage can break down, giving rise to striking quadratic responses.

The study was led by Manuel Suárez-Rodríguez—working under the guidance of Ikerbasque Professors Fèlix Casanova and Luis E. Hueso at CIC nanoGUNE, together with Prof. Marco Gobbi at the Materials Physics Center (CFM, CSIC-UPV/EHU).