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Rapid Eye Movements Enhance Information Acquisition

A model captures how the retina avoids tuning out during a fixed gaze.

Tiny, small-scale eye movements persist even when a human stares at a fixed point. Physiologists have long speculated about how these fixational eye movements, or “drift,” might help visual processing. Alexander Houston of the University of Glasgow in the UK and his collaborators now present a model that describes how both the stimulus—the visual scene—and the rapid eye movements affect visual performance [1]. They show how seemingly random eye movements serve to couple the spatial structure of a stimulus to a time-dependent visual response, with regimes that can be beneficial, detrimental, or ineffectual to information acquisition.

When you stare at an image, light travels through the lens in your eye before reaching the retina: the neural structure at the back of the eye that contains the photoreceptor array. Although the image appears clearly, if you stare fixedly for long enough, parts of it may fade from view. The retina “adapts” and stops signaling. Because of drift, however, each photoreceptor’s position shifts along a diffusive trajectory. In the model developed by Houston and his collaborators, these retinal movements impart a time dependence to spatial variations in the incoming light, overcoming the retina’s tendency to stop signaling.

FingerEye bridges touch and vision to improve robot handling before and after contact

To reliably complete various manual tasks, robots should be able to handle a variety of objects, ranging from items found in households to tools used in specific professional settings. While many existing robotic systems can now complete basic manual tasks, such as picking up objects and carrying them to a set location, most systems still struggle with tasks that entail the dexterous manipulation of objects.

The term dexterous manipulation describes the ability to skillfully and precisely move objects in nuanced ways, which is central to the completion of many of the tasks that humans tackle daily. Replicating this ability in robots can be very difficult, as it typically requires gathering and interpreting different types of sensory information.

Conventional approaches for robot manipulation rely on visual sensors, such as cameras, and tactile sensors, devices that pick up tactile information. Yet most existing tactile sensors only provide feedback after a robot touches an object, which makes it difficult to plan manipulation strategies in advance.

Superconductivity that shouldn’t exist: Physicists dissect the mind-boggling properties of a strange quantum material

The material UTe2 exhibits multiple forms of zero electrical resistance—a phenomenon known as superconductivity—and displays several puzzling properties. After UTe2 loses its superconductivity at a certain magnetic field, it becomes superconducting again under much higher fields.

Using a new high-field measurement technique, researchers from the Institute of Science and Technology Austria (ISTA) have explained this unusual superconducting behavior in a paper in Nature Communications. Their method is now being adopted at high-field laboratories worldwide.

Quantum materials exhibit exotic properties that make them relevant for next-generation technologies. While some scientists researching quantum materials seek to uncover specific properties for targeted applications, such as quantum computing, other researchers are curiosity-driven, searching for knowledge that hasn’t yet appeared in textbooks.

New microscope reveals previously hidden differences in photosynthetic light-harvesting antennae

How do photosynthetic organisms harvest light so efficiently? To help answer this question, researchers have developed an ultrafast transient absorption microscope with sensitivity approaching the single-molecule level.

Plants and photosynthetic bacteria have a wide variety of light-harvesting antennae in which pigment molecules are precisely arranged to utilize light energy efficiently. However, these molecular arrangements are not perfectly uniform and vary from particle to particle because of conformational distortions and fluctuations. Such structural variations are considered to perturb excited states and energy transfer processes triggered by light absorption. Because these early excitation dynamics initiate a cascade of photosynthetic photochemical reactions, understanding the effects of such fluctuations and heterogeneities is essential for revealing how phototrophic organisms maintain efficient and stable photosynthesis.

To analyze these fluctuations and heterogeneities, single-molecule fluorescence spectroscopy has been widely utilized. However, the fluorescence-based approach faces fundamental challenges in observing ultrafast and multistep processes, as well as non-fluorescent dark states and radical species.

How a free flow of information can amplify incorrect ideas

The idea that information should flow freely is deeply embedded in the design of social media. The assumption is that the more information is produced and shared, the better. However, simulations by a team of scientists including University of Groningen Professor of Artificial Intelligence Davide Grossi show that such an unrestricted flow of information can amplify incorrect ideas among like-minded people. The study is published in Proceedings of the National Academy of Sciences.

Information sharing is always beneficial. That is the central premise of digital communication platforms. If users want to communicate with one another, no amount of shared information is too much. But is this central premise correct? A team of social scientists and computer scientists used digital agents that shared unlimited information with perfect honesty to study how this affected the development of correct and incorrect ideas.

Hidden stripe pattern lets microscopes auto-focus across 400 times deeper range

Anyone who has ever used a microscope knows that it takes time to bring a sample into sharp focus. Each time you move the slide, the image blurs, and you have to stop and carefully turn a knob to bring everything back into clear view. For scientists and clinicians, even if the motion is semi-automated, that time quickly adds up as they work with dozens or hundreds of samples.

Now a team of scientists at Caltech has developed an inexpensive, robust fix for this problem that involves little more than a couple of LED lights and some physics-based processing. They describe the new autofocus technique, which they call Digital Defocus Aberration Interference (DAbI), in a paper published in Nature Communications.

The lead authors of the paper are graduate students Haowen Zhou, Ph.D., and Shi “Josh” Zhao, who completed the work in the lab of Changhuei Yang, the Thomas G. Myers Professor of Electrical Engineering, Bioengineering, and Medical Engineering at Caltech and a Heritage Medical Research Institute Investigator.

AI slashes the time needed to design better heat-harvesting devices

From wearable technology to industrial heat recovery, thermoelectric generators which convert waste heat into electricity have an enormous range of potential applications. So far, however, designing high-performing versions of these devices has remained a painstaking task.

Now, through new research published in Nature, Airan Li and colleagues at the National Institute for Materials Science in Japan have developed an AI-based tool that predicts device performance with greater than 99% accuracy, all while cutting computational time by around 10,000-fold.

Light can now be shaped in empty space, and it could simplify sensing and boost data links

Scientists at the University of East Anglia have uncovered a hidden property of light that allows it to twist, spin and behave differently—without mirrors, materials or special lenses. In a breakthrough that could transform medical testing, data transmission and future quantum technologies, researchers from the UK and South Africa have shown that light can be “programmed” simply by exploiting its natural geometry.

The discovery overturns decades of scientific thinking and reveals that light can develop chiral behavior—meaning it can act like a left or right hand—while traveling freely through space. This, the team says, could ultimately lead to a world where light carries information, probes biology, manipulates matter and protects quantum signals. The research is published in the journal Light: Science & Applications.

Investigating the disordered heart of glass

Recent research led by the University of Trento reveals that fundamental atomic vibrations remain unchanged also in ultra-stable glasses. This discovery advances the decade-long debate on the physics of disorder and opens the way to new applications, from electronics to pharmaceuticals. The research work was carried out by the Department of Physics in collaboration with other European research institutions and published in Physical Review X.

We are used to thinking of glass as a fragile and common material, but glass is still one of the greatest enigmas for physics. In crystals, atoms are arranged in geometric order, while chaos reigns in glass. This disorder generates unique properties, especially near absolute zero, where the glass behaves very differently from crystals. A study conducted by the Department of Physics of the University of Trento in collaboration with the European Synchrotron Radiation Facility (ESRF) in Grenoble and other European research centers sheds new light on this mystery.

The working group analyzed the so-called ultra-stable glasses, which are produced with advanced techniques that make them perfect candidates for the title of “ideal glass.” The first author of the paper is Irene Festi, who worked on the project for her Ph.D. thesis at the Department of Physics of the University of Trento. Giacomo Baldi, professor of Experimental Physics of Matter and head of the Laboratory of Structure and Dynamics of Complex Systems at the same Department of UniTrento, is the scientific coordinator of the study.

A mechanical blue LED: Stretching GaN shifts light from UV to blue without changing chemistry

A research team from the Faculty of Engineering at the University of Hong Kong (HKU) has successfully used mechanical stretching technology to dynamically control the emission color of gallium nitride (GaN) material from ultraviolet (UV) to blue light. This technological breakthrough provides a new semiconductor material control solution for future advanced power transistors, optoelectronic components, radio frequency components, and micro-LED displays.

The findings have been published in Physical Review X in a paper titled “Deep Elastic Strain Engineering of Free-Standing GaN Microbridge.”

Led by Professor Yang Lu from the Department of Mechanical Engineering, the team utilized micro-nano processing technology to fabricate single-crystalline GaN material into tiny bridge-like structures.

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