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Stars like our sun may maintain the same rotation pattern for life, contrary to 45 years of theoretical predictions

Researchers at Nagoya University in Japan have conducted the most detailed simulation of the interior of stars and disproved a theory scientists have believed for 45 years: that stars switch their rotation patterns as they age, with poles rotating faster than the equator in older stars. Scientists have now found that this switch may not occur. Stars maintain solar-type rotation, spinning fast at the equator and slow at the poles throughout their lifetime. The findings are published in Nature Astronomy.

Stars come in many different sizes, temperatures, and colors, ranging from red dwarfs to massive blue giants. Solar-type stars, the focus of this study, are those similar to our sun in mass and temperature. They are medium-sized, yellow stars that provide stable conditions for billions of years, long enough for planets orbiting them to potentially develop life.

Earth rotates as one solid piece, but because the sun is made of hot gas, it rotates differentially —different parts rotate at different speeds. The equator takes about 25 days to complete one rotation while the poles take about 35 days. This is known as solar-type differential rotation.

Liquid-metal pupil helps an artificial eye adapt to sudden light changes

Computer vision technologies are artificial intelligence (AI)-powered systems that can capture, analyze, and interpret visual data captured from real-world environments. While these systems are now widely used, many of them perform poorly under some lighting conditions and when the light in captured scenes changes abruptly.

Researchers at University of North Carolina at Chapel Hill, Westlake University and other institutes have developed a new artificial eye that draws inspiration from the eyes of humans, cats and other animals. This artificial eye, introduced in a paper published in Science Robotics, could be used to advance the sensing capabilities of robots, advanced security systems and autonomous vehicles.

“Our project grew from a simple problem: traditional machine vision systems (like the cameras deployed in self-driving cars or robots) struggle with extreme light changes, such as changes from pitch black to bright sunlight,” Dr. Kun Liang, first author of the paper, told Tech Xplore.

What’s inside neutron stars? New model could sharpen gravitational-wave ‘tide’ clues

Neutron stars harbor some of the most extreme environments in the universe: their densities soar to several times those of atomic nuclei, and they possess some of the strongest gravitational fields of any known objects, surpassed only by black holes. First observed in the 1960s, much of the internal composition of neutron stars is still unknown. Scientists are beginning to look to gravitational waves emitted by binary neutron‐star inspirals—pairs of mutually orbiting neutron stars—as possible sources of information about their interiors.

Physicists at the University of Illinois Urbana-Champaign, together with colleagues at the University of California, Santa Barbara, Montana State University, and the Tata Institute of Fundamental Research in India have made a major theoretical breakthrough in understanding how inspiraling binary neutron stars respond to tidal forces, a key step in elucidating neutron stars’ makeup. The team has proven that the time‐dependent tidal responses of such stars can be described in terms of their oscillatory behavior, or modes, extending an analogous result from Newtonian gravity to the relativistic setting.

This research was published as an Editors’ Suggestion in the journal Physical Review Letters on February 18, 2026, and paves the way to probing the internal structure of neutron stars and some of nature’s most extreme types of matter using gravitational waves.

Researchers detect complex emotions by combining multiple optical signals

Researchers have developed a new way to recognize human emotions by combining fiber-based physiological signals with thermal images of the face. The portable emotional recognition system could eventually be used to support at-home mental health monitoring, improve driver safety and make technology more responsive to human emotions.

“Unlike many existing approaches, our method does not rely on facial expressions, which can be consciously controlled or exaggerated,” said research team leader Rui Min from Beijing Normal University at Zhuhai (BNU Zhuhai) in China.

“Instead, it focuses on natural bodily responses that occur automatically. By combining multiple types of optical sensing and higher-level physiological interpretation, our system can more accurately capture emotion than those using a single type of input.”

New Tool for Sculpting Single Photons

Researchers can adjust the frequency and bandwidth of single photons inside an optical fiber, which will be useful for future quantum networks.

Future quantum technologies will require practical techniques for adjusting the frequencies and bandwidths of individual photons to optimize them for various purposes without losing the delicate quantum data that they carry. Now researchers have improved on previous technology and have shown how both properties can be tuned over a wide range inside a short length of standard optical fiber [1]. They expect that this technique will be more practical and effective than current alternatives and will find wide use in interfacing devices in future quantum computing and communications networks.

Photons are likely to provide the means for transmitting information within future quantum networks, but frequent changes to their properties will be required in order for them to carry out a diversity of tasks. For example, a trapped-ion quantum memory emits or absorbs photons at a specific visible wavelength with an extremely narrow bandwidth, which means that a photon with which it interacts must be produced as a relatively long light pulse. In contrast, a high-speed fiber-optic channel works best with infrared photons having much broader bandwidths, which require short light pulses.

Multiply and subtract your way to more lifelike VR avatars

POSTECH’s (Pohang University of Science and Technology) Professor Inseok Hwang’s team has developed ArithMotion, a mobile virtual reality (VR) system that enables anyone to express a wide range of avatar motions with ease. Using simple arithmetic-like controls, users can scale an avatar’s motion up or down and reverse it into an opposite response, allowing more natural nonverbal communication without expensive equipment.

On social VR platforms such as VRChat, people communicate through their avatars’ movements, facial expressions, and gestures. In particular, bodily motions are a key channel for building emotional connections between users and enhancing immersion and a sense of agency. However, because most users do not have access to expensive full-body tracking equipment, they are often limited to repeating preset motions—making natural, spontaneous communication difficult.

In this study, the team focused on a natural form of social behavior known as “peer relativity”—the way people instinctively mirror others’ actions or respond in the opposite direction. They brought this phenomenon directly into VR avatars: when another player celebrates a win with an excited gesture, your avatar can respond in the same way, while threatening behavior from others can trigger a more defensive, protective reaction—preserving a more lifelike sense of social realism.

New study shows how sickle cell affects brain function

Sickle cell disease is often thought of solely as a blood disorder, but new research from the Wood Neuro Research Group provides measurable evidence that it can reshape how brain networks function. Previous neuroimaging studies have relied on functional connectivity to show that adults with sickle cell disease may experience changes in how brain networks communicate among one another, potentially compensating for reduced oxygen delivery. However, this method is limited in determining the directionality or influence between networks.

“Red blood cells that carry oxygen to the brain are altered by the disease, resulting in reduced oxygen delivery to all regions of the brain and long-term changes in how it functions,” outlined Nahom Mossazghi, biomedical engineering Ph.D. student and the study’s first author. “The brain actively recruits other regions to help process information, which we do not see in people without the disease.”

The study, published in Human Brain Mapping, used MRI and advanced analytical tools originally developed in economics to examine how different brain networks influence one another. Instead of functional connectivity, effective connectivity was used to address a gap in the field and interpret how specific networks support one another in response to the disease-related changes.

Temporal lobe epilepsy: A new strategy to correct abnormal electrical activity

Many patients suffer from epilepsy that cannot be controlled by current medications. Surgical removal of epileptogenic brain regions is effective in only about half of cases, and not all patients are eligible for the procedure. For these individuals, therapeutic options remain severely limited. Researchers from the Paris Brain Institute and the Institut du Fer à Moulin in Paris have now taken an important step forward: they have identified two molecules capable of reducing seizure frequency by targeting a mechanism that has so far received little attention. Their findings are published in Proceedings of the National Academy of Sciences.

For the brain to function normally, it must continuously regulate its electrical activity. One of the key mechanisms involved is GABAergic signaling, a natural inhibitory system that controls neuronal activity and prevents the electrical bursts that characterize epileptic seizures. This braking system depends on a delicate balance: the concentration of chloride inside neurons.

An ion transporter known as KCC2 is responsible for removing excess chloride from nerve cells. When it functions poorly—as observed in many neurological disorders, including mesial temporal lobe epilepsy, the most common form of focal epilepsy in adults—chloride accumulates inside neurons. As a result, GABAergic signals, instead of inhibiting neuronal activity, can paradoxically excite it.

Material previously thought to be quantum is actually a new, non-quantum state of matter

Magnetic materials in a quantum spin liquid phase are of great interest in the pursuit of exotic state of matter and quantum computation. But in the quantum realm, things are not always what they seem. A study, published in Science Advances and co-led by Rice University’s Pengcheng Dai, found that the material cerium magnesium hexalluminate (CeMgAl11 O19) was not actually in a quantum spin liquid phase despite evidence suggesting it was.

“The material had been classified as a quantum spin liquid due to two properties: observation of a continuum of states and lack of magnetic ordering,” said Bin Gao, co-first author and a research scientist at Rice. “But closer observation of the material showed that the underlying cause of these observations wasn’t a quantum spin liquid phase.”

Water-window X-rays without a synchrotron: How graphite flakes could shrink bioimaging tools

Researchers from Nanyang Technological University, Singapore (NTU Singapore) have found a new way to produce X-rays with wavelengths in what is called the “water window.” This new method holds promise in making bioimaging X-ray machines smaller and more flexible to use.

Water-window X-rays are useful for bioimaging because they visualize biological cells at high contrast without staining them or requiring potentially damaging preparation.

However, some tabletop machines only produce radiation in a fixed range of energies, so more machines are needed if X-rays of varying energies are required to improve image contrast. Even then, they cannot cover the full spectrum of energies in the water window. There are single machines that can flexibly produce X-rays of different energies, but these are expensive synchrotrons larger than a house and difficult for most researchers to access.

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