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Mar 2, 2024

Study shows that similarly charged particles can sometimes attract, rather than repel

Posted by in categories: nanotechnology, particle physics

‘Opposites charges attract; like charges repel’ is a fundamental principle of basic physics. But a new study from Oxford University, published in Nature Nanotechnology (“A charge-dependent long-ranged force drives tailored assembly of matter in solution”), has demonstrated that similarly charged particles in solution can, in fact, attract each other over long distances. Just as surprisingly, the team found that the effect is different for positively and negatively charged particles, depending on the solvent.

The study found that negatively charged silica microparticles suspended in water attracted each other to form hexagonally arranged clusters. (Image: Zhang Kang)

Besides overturning long-held beliefs, these results have immediate implications for a range of processes that involve interparticle and intermolecular interactions across various length-scales, including self-assembly, crystallisation, and phase separation.

Mar 2, 2024

Butterfly mating behaviors inspire next level brain-like computing

Posted by in categories: chemistry, robotics/AI

Cutting-edge research harnesses butterfly mating behaviors to create a groundbreaking visuochemical integration platform. This bio-inspired hardware, merging visual and chemical data, paves the way for advanced multisensory decision-making in artificial intelligence.

Mar 2, 2024

Ableism Puts Neurodivergent Students at a Disadvantage

Posted by in categories: biotech/medical, neuroscience

Physics has a diversity problem: those with identities outside of the majority “able-bodied, white, cis, and male” face significant barriers to entry. While efforts in the US to level the playing field are beginning to show success, studies continue to find that minority physicists will likely experience some form of bigotry, bias, or barrier during their career that will hamper their chances of success. These inequities and biases range from skewed course structures that favor specific learning styles (see Research News: Restructuring Classes Can Level the Playing Field) to systemic prejudices that hinder some groups from gaining grants (see News Feature: Systemic Racism Reflected in Grant Allocations, Researchers Argue) to unconscious biases that lead to the significant undercitation of minority physicists compared to their white, male counterparts (see News Feature: The Uneven Spread of Citations). All these factors can have serious career consequences, with negative experiences being a key factor driving people to leave the field.

One lesser-studied aspect of identity and how it impacts a person’s experience in physics is neurodivergence—a nonmedical umbrella term used to describe people whose brains process information in way that is different to what is considered normal. Now Geraldine Cochran of Ohio State University and Liam McDermott and Nazeer Mosley, both of Rutgers University, New Jersey, have developed a framework for interpreting the experiences of this group of people [1]. An initial analysis of interviews with three neurodivergent physicists shows that, while this group reports little outright discrimination or violence, structural ableism negatively impacted their time as students. “There are more neurodivergent people entering college than ever before,” McDermott says. “But their needs regularly get overlooked.”

A person who identifies as neurodivergent may have a neurological disorder, such as autism or Tourette’s syndrome; they may have a learning disability, such as dyslexia (which affects language processing) or dyscalculia (which affects number processing); or they could have a mental illness, such as depression or anxiety. For their study, Cochran, McDermott, and Mosley interviewed three physicists who identified as being neurodivergent and who pursued nonacademic careers after completing their undergraduate degrees. All three identified as having attention-deficit hyperactivity disorder (ADHD) and anxiety. Sky (the interviewees were all given pseudonyms) also has depression, Catalina has depression and dyslexia, and Henry has epilepsy. The interviews covered the trio’s undergraduate experiences. Cochran, McDermott, and Mosley then analyzed the trio’s answers using their newly developed “Critical Disability Physics Identity” framework.

Mar 2, 2024

Cold Chemistry is Different

Posted by in categories: chemistry, particle physics, quantum physics, space travel

Experiments demonstrate some of the unusual features of molecular reactions that occur in the deep cold of interstellar space.

Many common small molecules are formed in interstellar space, and their low temperatures are expected to have profound effects on their chemical reactions because of quantum-mechanical effects that are masked at higher temperatures. Researchers have now demonstrated some of these cold chemistry phenomena—such as the effects of molecular rotation and collision energy on reaction rates—in a reaction between a hydrogen ion and an ammonia molecule in the lab. The results, while intuitively surprising at first glance, can be explained by a careful theoretical analysis of the quantum chemistry.

Measuring reaction rates at low temperatures is useful for testing quantum-chemical theory because in those conditions molecules may occupy only a few well-defined quantum states. Such experiments could also offer insights into chemical processes in the cold clouds of gas in star-forming regions of interstellar space, where many of the simple molecules that make up solar systems are formed. But low-temperature experiments are difficult, especially for charged atoms and molecules (ions), because they are very sensitive to stray electric fields in the environment, which accelerate and heat up the ions.

Mar 2, 2024

Applying a Twist to Light

Posted by in category: futurism

Researchers have determined the amount of transverse orbital angular momentum that a type of optical vortex carries per photon, an important step for future applications.

Mar 2, 2024

Seeking Solutions to Underwater Noise Pollution

Posted by in categories: engineering, finance, space

From early in his career, Kamal Kesour understood the damaging effects of urban noise and was aware of the instrumentation used to measure and control it. He had lived in big cities, and after his PhD he went to work for an environmental consulting firm that specialized in urban noise. But it wasn’t until later, during a research position at Innovation Maritime in Canada, that he realized marine mammals can experience similarly noisy environments. This noise comes from underwater vibrations generated by shipping vessels transporting goods around the world. Kesour now has a career helping to make maritime transportation vessels less noisy.

Kesour has spent the past few years in Rimouski, Canada, at the Marine Acoustic Research Station (MARS), which lies on the banks of the St. Lawrence Estuary and is jointly led by Innovation Maritime, the Rimouski Institute of Marine Sciences, and engineering consultancy OpDAQ systems. There, he measures ambient underwater noise from ships as they pass on their way to and from the Atlantic Ocean or North America’s Great Lakes. He also conducts on-ship measurements to help pinpoint noise sources and to “fingerprint” the vibrations of individual ships. Physics Magazine caught up with Kesour to learn more about his measurements and their implications for noise pollution produced by the shipping industry.

All interviews are edited for brevity and clarity.

Mar 2, 2024

Scientists Demonstrate Effective Fusion “Spark Plug” in Groundbreaking Experiments

Posted by in categories: energy, innovation

Researchers at the University of Rochester’s Laboratory for Laser Energetics (LLE) have led experiments showcasing an efficient “spark plug” for direct-drive approaches to inertial confinement fusion (ICF). In a pair of studies featured in Nature Physics, the team shares their findings and details the potential for scaling up these methods, aiming for successful fusion in a future facility.

LLE is the largest university-based U.S. Department of Energy program and hosts the OMEGA laser system, which is the largest academic laser in the world but still almost one hundredth the energy of the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in California. With OMEGA, Rochester scientists completed several successful attempts to fire 28 kilojoules of laser energy at small capsules filled with deuterium and tritium fuel, causing the capsules to implode and produce a plasma hot enough to initiate fusion reactions between the fuel nuclei. The experiments caused fusion reactions that produced more energy than the amount of energy in the central hot plasma.

The OMEGA experiments use direct laser illumination of the capsule and differ from the indirect drive approach used on the NIF. When using the indirect drive approach, the laser light is converted into X-rays that in turn drive the capsule implosion. The NIF used indirect drive to irradiate a capsule with X-rays using about 2,000 kilojoules of laser energy. This led to a 2022 breakthrough at NIF in achieving fusion ignition —a fusion reaction that creates a net gain of energy from the target.

Mar 2, 2024

Groundbreaking New Tiny Power Converters Run on Vibrational Energy

Posted by in categories: computing, mobile phones

Scientists from the University of California San Diego and CEA-Leti have created a revolutionary piezoelectric-based DC-DC converter that unifies all power switches onto a single chip to increase power density. This new power topology, which extends beyond existing topologies, blends the advantages of piezoelectric converters with capacitive-based DC-DC converters.

The power converters the team developed are much smaller than the huge, bulky inductors currently used for this role. The devices could eventually be used for any type of DC-DC conversation, in everything from smartphones, to computers, to server farms and AR/VR headsets.

Mar 2, 2024

Crystalline Quest: The International Pursuit of Lunar Ice Deposits

Posted by in categories: space travel, sustainability

Chandrayaan-3’s landing on the Moon and subsequent sulfur detection has propelled lunar ice research forward, aiding NASA ’s plans for a sustainable lunar station. These developments highlight the growing collaboration in space exploration.

Building a space station on the Moon might seem like something out of a science fiction movie, but each new lunar mission is bringing that idea closer to reality. Scientists are homing in on potential lunar ice reservoirs in permanently shadowed regions, or PSRs. These are key to setting up any sort of sustainable lunar infrastructure.

In late August 2023, India’s Chandrayaan-3 lander touched down on the lunar surface in the south polar region, which scientists suspect may harbor ice. This landing marked a significant milestone not only for India but for the scientific community at large.

Mar 2, 2024

Scientists Discover Bizarre Material Where Electrons Stand Still

Posted by in categories: materials, quantum physics

Scientists at Rice University have uncovered a first-of-its-kind material: a 3D crystalline metal in which quantum correlations and the geometry of the crystal structure combine to frustrate the movement of electrons and lock them in place.

The find is detailed in a study published in Nature Physics. The paper also describes the theoretical design principle and experimental methodology that guided the research team to the material. One part copper, two parts vanadium, and four parts sulfur, the alloy features a 3D pyrochlore lattice consisting of corner-sharing tetrahedra.

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