Lifeboat Foundation

Scientists have yet to obtain a complete microscopic understanding of how a supercooled liquid behaves as it turns into a glass. Different theories can capture different aspects of the spatial and temporal dynamics of this process, but the assumptions behind these theories are, in some cases, mutually exclusive. Now Yoshihiko Nishikawa at Tohoku University, Japan, and Ludovic Berthier at the University of Montpellier, France, reconcile two competing descriptions of this glass-transition behavior using a recently developed lattice model [1].

A prominent glass-transition theory known as random first-order transition theory holds that a cooling glass-forming liquid adopts a mosaic-like static structure with finite-range order. In this framework, so-called dynamic fluctuations—reorganizations of a material’s particles—occur when boundaries between mosaic “tiles” collectively rearrange. These fluctuations are fundamentally tied to static, region-to-region variations in a material’s structure. A competing theory known as dynamic-facilitation theory contains no assumptions about the system’s static structure or region-to-region variations. This theory postulates that dynamic fluctuations occur via local, small-scale particle rearrangements that trigger a reorganizational chain reaction that then propagates through the material.

For their study, Nishikawa and Berthier used a different theory to probe the glass transition of a supercooled liquid. Their three-dimensional lattice theory exhibits mosaic-like structural variations that are consistent with those from random first-order transition theory. However, the researchers found that the model’s predictions for the dynamic fluctuations more closely resemble those of the dynamic-facilitation framework. Nishikawa says that no current experiments can directly confirm the occurrence of these behaviors in real glass-forming materials. But he hopes to use the three-dimensional lattice model to reproduce some recently observed indirect experimental data.

A theoretical study finds that the most energy-efficient way to control an active-matter system is to drive it at finite speed—unlike passive-matter systems.

The control of active matter, a class of systems in which each constituent constantly converts energy into directed motion, holds great potential for applications ranging from the targeted delivery of drugs to the creation of smart materials. Using an active-matter system to achieve a particular goal requires that one can efficiently drive it from one state to another. However, active matter’s intrinsic nonequilibrium condition presents a major challenge for theoretical treatments, meaning the most efficient way of driving a system is often difficult to predict. Now Luke Davis at the University of Luxembourg and colleagues have introduced a general framework to determine thermodynamically optimal protocols to drive active systems between different states in a way that minimizes the associated heat dissipation [1].

The recent breakthroughs in laser-based fusion have given a boost to a number of start-up companies—one of which has plans to replace the lasers with a high-speed projectile.

A network-theory model, tested on the work of Johann Sebastian Bach, offers tools for quantifying the amount of information delivered to a listener by a musical piece.

Great pieces of music transport the audience on emotional journeys and tell stories through their melodies, harmonies, and rhythms. But can the information contained in a piece, as well as the piece’s effectiveness at communicating it, be quantified? Researchers at the University of Pennsylvania have developed a framework, based on network theory, for carrying out these quantitative assessments. Analyzing a large body of work by Johan Sebastian Bach, they show that the framework could be used to categorize different kinds of compositions on the basis of their information content [1]. The analysis also allowed them to pinpoint certain features in music compositions that facilitate the communication of information to listeners. The researchers say that the framework could lead to new tools for the quantitative analysis of music and other forms of art.

To tackle complex systems such as musical pieces, the team turned to network theory—which offers powerful tools to understand the behavior of discrete, interconnected units, such as individuals during a pandemic or nodes in an electrical power grid. Researchers have previously attempted to analyze the connections between musical notes using network-theory tools. Most of these studies, however, ignore an important aspect of communication: the flawed nature of perception. “Humans are imperfect learners,” says Suman Kulkarni, who led the study. The model developed by the team incorporated this aspect through the description of a fuzzy process through which a listener derives an “inferred” network of notes from the “true” network of the original piece.

A proposed device can repeatedly grab pairs of electrons from a superconductor and separate them while preserving their entangled state.

Researchers have made a landmark discovery in quantum physics by observing and quantitatively characterizing the many-body pairing pseudogap in unitary Fermi gases, a topic of debate for nearly two decades. This finding not only resolves long-standing questions about the nature of the pseudogap in these gases but also suggests a potential link to the pseudogap observed in high-temperature superconductors. Credit: SciTechDaily.com.

Researchers have conclusively observed the many-body pairing pseudogap in unitary Fermi gases, advancing our understanding of superconductivity mechanisms.

A research team led by Professors Jianwei Pan, Xingcan Yao, and Yu’ao Chen from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences, has for the first time observed and quantitatively characterized the many-body pairing pseudogap in unitary Fermi gases.

Jenniskens’ collaborators at the Museum für Naturkunde officially announced that the first examinations of one of these pieces with an electron beam microprobe prove the typical mineralogy and chemical composition of an achondrite of the aubrite type.

The official classification now aligns with what many suspected from merely looking at the images of the strange meteorites that fell near Berlin on January 21, 2024. They belong to a rare group called “aubrites.”

“They were devilishly difficult to find because, from a distance, they look like other rocks on Earth,” said SETI Institute meteor astronomer Dr. Peter Jenniskens. “Close up, not so much.”

A new protective layer developed by researchers improves gold catalysts’ durability, potentially expanding their industrial applications and efficiency. Credit: SciTechDaily.com.

A protective layer applied to gold nanoparticles can boost its resilience.

For the first time, researchers including those at the University of Tokyo discovered a way to improve the durability of gold catalysts by creating a protective layer of metal oxide clusters. The enhanced gold catalysts can withstand a greater range of physical environments compared to unprotected equivalent materials.

Dr. Hanan Herzig Sheinfux, from Bar-Ilan University: “What started as a chance discovery, may well open the way to new quantum applications, pushing the boundaries of what we thought was possible.”

In a significant leap forward for quantum nanophotonics, a team of European and Israeli physicists, introduces a new type of polaritonic cavities and redefines the limits of light confinement. This pioneering work, detailed in a study published today (February 6) in Nature Materials, demonstrates an unconventional method to confine photons, overcoming the traditional limitations in nanophotonics.

Physicists have long been seeking ways to force photons into increasingly small volumes. The natural length scale of the photon is the wavelength and when a photon is forced into a cavity much smaller than the wavelength, it effectively becomes more “concentrated.”