Toggle light / dark theme

A research team at POSTECH has developed a novel multidimensional sampling theory to overcome the limitations of flat optics. Their study not only identifies the constraints of conventional sampling theories in metasurface design but also presents an innovative anti-aliasing strategy that significantly enhances optical performance. Their findings were published in Nature Communications.

Flat optics is a cutting-edge technology that manipulates light at the nanoscale by patterning ultra-thin surfaces with nanostructures. Unlike traditional optical systems that rely on bulky lenses and mirrors, enables ultra-compact, high-performance optical devices. This innovation is particularly crucial in miniaturizing smartphone cameras (reducing the “camera bump”) and advancing AR/VR technologies.

Metasurfaces, one of the most promising applications of flat optics, rely on hundreds of millions of nanostructures to precisely sample and control the phase distribution of light. Sampling, in this context, refers to the process of converting analog optical signals into discrete data points—similar to how the human brain processes visual information by rapidly capturing multiple images per second to create continuous motion perception.

A pair of physicists at the University of Crete has found that some types of biological magnetoreceptors used by various creatures to navigate, operate at or near the quantum limit. In their paper published in the journal PRX Life, I. K. Kominis and E. Gkoudinakis describe how they worked the problem of magnetic sensing in tiny animals in reverse by putting bounds on unknown quantum boundaries, and what it showed about the navigation abilities of certain animals.

Prior research has shown that many creatures use the Earth’s as a navigation aid. Some sharks, fish and birds, for example, use it to help them traverse long distances. Different animals also have different types of magnetic sensors, including radical-pair, induction and magnetite mechanisms.

Radical-pair works by sensing correlations between unpaired electrons attached to certain molecules. Induction works by turning energy in the magnetic field into electricity and then sensing the electrical charge. And magnetite-based magnetoreception involves sensing the movement or orientation of tiny iron crystals in the body, similar to a human-made compass.

When people think about fiber optic cables, it’s usually about how they’re used for telecommunications and accessing the internet. But fiber optic cables—strands of glass or plastic that allow for the transmission of light—can be used for another purpose: imaging the ground beneath our feet.

MIT Department of Earth, Atmospheric and Planetary Sciences (EAPS) Ph.D. student Hilary Chang recently used the MIT fiber optic cable network to successfully image the ground underneath campus using a method known as distributed acoustic sensing (DAS). By using existing infrastructure, DAS can be an efficient and effective way to understand ground composition, a critical component for assessing the seismic hazard of areas, or how at risk they are from earthquake damage.

“We were able to extract very nice, coherent waves from the surroundings, and then use that to get some information about the subsurface,” says Chang, the lead author of a recent paper describing her work that was co-authored with EAPS Principal Research Scientist Nori Nakata. The study is published in The Leading Edge journal.

Recent advances in the fields of human-infrastructure interaction, electronic engineering, robotics and artificial intelligence (AI) have opened new possibilities for the development of assistive and medical technologies. These include devices that can assist individuals with both physical and cognitive disabilities, supporting them throughout their daily activities.

Researchers at the University of Michigan recently developed CoNav, a smart controlled via a Robot Operating System (ROS) based framework. The new wheelchair, presented in a paper on the arXiv preprint server, could help to improve the quality of life of individuals who are temporarily or permanently unable to walk, allowing them to move in their surroundings more intuitively and autonomously.

“The inspiration for this work stems from a broader challenge in assistive mobility for people with disabilities (PWD),” Vineet Kamat, senior author of the paper, told Tech Xplore.

With an assist from the NEID spectrograph, a team of astronomers have confirmed the existence of exoplanet Gaia-4b—one of the most massive planets known to orbit a low-mass star. Gaia-4b is also the first planet detected by the European Space Agency’s Gaia spacecraft using the astrometric technique.

NEID is a high-precision radial-velocity spectrograph that is designed to measure the extremely minute wobble of using the radial velocity effect. This effect results from the mutual gravitational force between a planet and its which causes the star’s position to shift very slightly as the planet travels around it. With this powerful capability, one of NEID’s main science goals is to confirm exoplanet candidates found by other exoplanet missions.

NEID is mounted on the WIYN 3.5-meter Telescope at the U.S. National Science Foundation Kitt Peak National Observatory (KPNO), a program of NSF NOIRLab.

How do languages balance the richness of their structures with the need for efficient communication? To investigate, researchers at the Leibniz Institute for the German Language (IDS) in Mannheim, Germany, trained computational language models on a vast dataset covering thousands of languages.

They found that languages that are computationally harder to process compensate for this increased complexity with greater efficiency: more complex languages need fewer symbols to encode the same message. The analyses also reveal that larger language communities tend to use more complex but more efficient languages.

Language models are computer algorithms that learn to process and generate language by analyzing large amounts of text. They excel at identifying patterns without relying on predefined rules, making them valuable tools for linguistic research. Importantly, not all models are the same: their internal architectures vary, shaping how they learn and process language. These differences allow researchers to compare languages in new ways and uncover insights into linguistic diversity.

The Sudan virus, a close relative of Ebola, has a fatality rate of 50% but remains poorly understood in terms of how it infects cells. Currently, no approved treatments exist. To address this critical gap in pandemic preparedness, researchers at the University of Minnesota and the Midwest Antiviral Drug Discovery (AViDD) Center investigated how this deadly virus attaches to human cells.

Like Ebola, the Sudan virus enters cells by binding to NPC1, a protein responsible for cholesterol transport. Using , the researchers mapped how the Sudan virus interacts with the human NPC1 receptor. Their findings revealed that four key amino acid differences in the receptor-binding proteins of Sudan and Ebola viruses enable the Sudan virus to bind to human NPC1 with nine times greater affinity than Ebola, which may contribute to its high fatality rate.

Building on this discovery, the team predicted the receptor-binding affinities of three other filoviruses closely related to Sudan and Ebola. They also examined how the Sudan virus binds to NPC1 receptors in bats, which are believed to be natural hosts of filoviruses. These findings provide crucial insights into the infection mechanisms and evolutionary origins of Sudan virus and related filoviruses, paving the way for potential treatments.

A graduate research assistant at The University of Alabama in Huntsville (UAH), a part of The University of Alabama system, has published a paper in the journal Astronomy & Astrophysics that builds on an earlier study to help understand why the solar corona is so hot compared to the surface of the sun itself.

To shed further light on this age-old mystery, Syed Ayaz, a Ph.D. candidate in the UAH Center for Space Plasma and Aeronomic Research (CSPAR), employed a statistical model known as a Kappa distribution to describe the velocity of particles in space plasmas, while incorporating the interaction of suprathermal particles with kinetic Alfvén waves (KAWs).

KAWs are oscillations of the charged particles and as they move through the , caused by motions in the photosphere, the sun’s outer shell. The waves are a valuable tool for modeling various phenomena in the solar system, including particle acceleration and wave-particle interactions.

A team of physicists affiliated with multiple institutions in China has measured a pulse of light in 37 dimensions. In their paper published in Science Advances, the group explains that their experiment was meant to demonstrate that quantum mechanics is more nonclassical than thought.

Quantum mechanics involves how things work at the , while describes classical theory, which has aspects of what physicists call local realism, where things happen around us in the ways that we expect them to happen and in the order we expect.

Physicists have tried and failed to unite the two theories for decades. The problem has only grown more difficult in recent years as research efforts have shown that the differences between them are greater than thought. In this new effort, the researchers in China sought to see how far nonclassical differs from classical theory by carrying out an experiment to demonstrate the Greenberger–Horne–Zeilinger (GHZ) paradox.

Foams are an essential component of many different drinks and foods: from a frothy head of beer to coffee crema, bread and ice cream. Despite their ubiquity, little is actually known or understood about these highly complex systems.

Collaboration between the Institut Laue-Langevin (ILL) and Aarhus University has connected unique capabilities to investigate foam with critically relevant challenges, bringing a greener food future a step closer. The study is published in the Journal of Colloid and Interface Science.

Understanding the behavior of foam requires characterization of the structure. “That’s not easy,” explains Leonardo Chiappisi, ILL researcher and coordinator of the Partnership for Soft Condensed Matter (PSCM).