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Chinese astronomers investigated the spectral and temporal properties of a black hole X-ray binary system known as SLX 1746-331, during its recent outburst. Results of the study, published in The Astrophysical Journal Letters, could help us better understand the nature of this system and its behavior.

X-ray binaries are composed of a normal star or a white dwarf transferring mass onto a compact neutron star or a black hole. Based on the mass of the companion star, astronomers divide them into low-mass X-ray binaries (LMXBs) and high-mass X-ray binaries (HMXBs).

SLX 1746-331 is a transient black hole LMXB at a distance of about 35,200 light years, discovered in 1985. After a 13-year-long period of quiescence, it entered an outburst in 2023, which peaked on March 14.

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Chapman–Enskog theory has long provided an accurate description of the transport properties of dilute gas mixtures. At elevated densities, revised Enskog theory (RET) provides a framework for describing the departure of the transport properties from their dilute-gas values. Various methods of adapting RET for the description of real fluids have been proposed in the literature. The methods have in common that they incorporate one or more length scales to describe molecular interactions. With few exceptions, the required length scales have been estimated from experimental transport property data. In this work, we introduce two transfer lengths that describe the residual transport of momentum and energy. We derive a model called the exchange-weighted closest approach (EWCA), which links the transfer lengths to the intermolecular potential. Combining the EWCA model with Mie potentials fitted to experimental equilibrium properties yields accurate predictions for several real fluids, including a binary mixture. At higher temperatures, the theory is accurate at surprisingly high densities, even up to the liquid–solid transition of argon. We demonstrate how the transfer lengths can be computed from experimental data or correlations for the transport properties. The transfer lengths obtained in this manner are in good agreement with those obtained from the EWCA model paired with an accurate ab initio potential for argon. The results suggest that kinetic theory, after further developments, can become a predictive theory also for liquids.

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Microplastics have been found almost everywhere that scientists have looked for them. Now, according to research published in Environment & Health, these bits of plastic—from 1 to 62 micrometers long—are present in the filtered solutions used for medical intravenous (IV) infusions. The researchers estimate that thousands of plastic particles could be delivered directly to a person’s bloodstream from a single 8.4-ounce (250-milliliter) bag of infusion fluid.

In clinical settings, IV infusions are packaged in individual plastic pouches and deliver water, electrolytes, nutrients or medicine to patients. The base of these infusions is a that contains filtered water and enough salt to match the content of human blood. Research from the 1970s suggests IV fluid bags can contain solid particles, but few scientists have followed up on what those particles are made of.

Researchers Liwu Zhang, Ventsislav Kolev Valev and colleagues suspected that these particles could be microplastics that—upon —would enter the recipient’s bloodstream and potentially cause . So, they set out to analyze the types and amounts of particles in commercial IV fluid bags.

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Density functional theory (DFT) is a cornerstone tool of modern physics, chemistry, and engineering used to explore the behavior of electrons. While essential in modeling systems with many electrons, it suffers from a well-known flaw called self-interaction error. A recent study has identified a new area where a correction for this error breaks down.

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An international collaboration headed by researchers in the Department of Physics has shown that additive manufacturing offers a realistic way to build large-scale plastic scintillator detectors for particle physics experiments.

In 2024, the T2K Collaboration started to collect new neutrino data following several upgrades to the experiment that included new types of detectors. One of these, called SuperFGD, has a mass of about 2 tons of sensitive volume and is made of approximately two million cubes. Each cube is made of plastic scintillator (PS) material that emits light when a charged particle passes through it.

Neutrinos carry no charge, as their name indicates, but they sometimes interact with other particles, then produce electrons, protons, muons or pions that can be detected. Each PS cube is traversed by three orthogonal optical fibers that collect the scintillation light and guide it to 56,000 photodetectors. The data reveal three-dimensional (3D) particle tracks, which in turn allow researchers to learn more about neutrinos.

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In a scene toward the end of the 2006 film, “X-Men: The Last Stand,” a character claps and sends a shock wave that knocks out an opposing army. Sunny Jung, professor of biological and environmental engineering in the College of Agriculture and Life Sciences, was intrigued. “It made me curious about how the wave propagates when we clap our hands,” Jung said.

Jung is senior author of a study, published in Physical Review Research, that elucidates the complex physical mechanisms and involved in a handclap, with potential applications in bioacoustics and personal identification, whereby a handclap could be used to identify someone.

“Clapping hands is a daily, human activity and form of communication,” Jung said. “We use it in religious rituals, or to express appreciation: to resonate ourselves and excite ourselves. We wanted to explore how we generate the sound depending on how we clap our hands.”

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The ultrafast dynamics and interactions of electrons in molecules and solids have long remained hidden from direct observation. For some time now, it has been possible to study these quantum-physical processes—for example, during chemical reactions, the conversion of sunlight into electricity in solar cells and elementary processes in quantum computers—in real time with a temporal resolution of a few femtoseconds (quadrillionths of a second) using two-dimensional electronic spectroscopy (2DES).

However, this technique is highly complex. Consequently, it has only been employed by a handful of research groups worldwide to date. Now a German-Italian team led by Prof. Dr. Christoph Lienau from the University of Oldenburg has discovered a way to significantly simplify the experimental implementation of this procedure. “We hope that 2DES will go from being a methodology for experts to a tool that can be widely used,” explains Lienau.

Two doctoral students from Lienau’s Ultrafast Nano-Optics research group, Daniel Timmer and Daniel Lünemann, played a key role in the discovery of the new method. The team has now published a paper in Optica describing the procedure.

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Physicists at the University of Cologne have taken an important step forward in the pursuit of topological quantum computing by demonstrating the first-ever observation of Crossed Andreev Reflection (CAR) in topological insulator (TI) nanowires.

This finding, published under the title “Long-range crossed Andreev reflection in topological insulator nanowires proximitized by a superconductor” in Nature Physics, deepens our understanding of superconducting effects in these materials, which is essential for realizing robust quantum bits (qubits) based on Majorana zero-modes in the TI platform—a major goal of the Cluster of Excellence Matter and Light for Quantum Computing (ML4Q).

Quantum computing promises to revolutionize information processing, but current qubit technologies struggle with maintaining stability and error correction. One of the most promising approaches to overcoming these limitations is the use of topological superconductors, which can host special quantum states called Majorana zero-modes.

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Researchers from RMIT University and the University of Melbourne have discovered that water generates an electrical charge up to 10 times greater than previously understood when it moves across a surface.

The team, led by Dr. Joe Berry, Dr. Peter Sherrell and Professor Amanda Ellis observed that when a water droplet became stuck on a tiny bump or rough spot, the force built up until it “jumped or slipped” past an obstacle, creating an irreversible charge that had not been reported before.

The new understanding of this “stick-slip” motion of water over a surface paves the way for surface design with controlled electrification, with potential applications ranging from improving safety in fuel-holding systems to boosting energy storage and charging rates.

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Once described by Einstein as “spooky action at a distance,” quantum entanglement may now seem less intimidating in light of new research findings.

Osaka Metropolitan University physicists have developed new, simpler formulas to quantify quantum entanglement in strongly correlated electron systems and applied them to study several . Their results offer fresh perspectives into quantum behaviors in materials with different physical characteristics, contributing to advances in .

The study is published in Physical Review B.

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