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Space debris poses growing threat, but new study suggests cleanup is feasible

High up in Earth’s orbit, millions of human-made objects large and small are flying at speeds of over 15,000 miles per hour. The objects, which range from inactive satellites to fragments of equipment resulting from explosions or collisions of previously launched rockets, are space debris, colloquially referred to as space junk. Sometimes the objects collide with each other, breaking into even smaller pieces.

No matter the size, all of this debris poses a problem. Flying at high speeds caused by prior launches or explosions, they create danger for operational satellites and spacecraft, which are vital for the efficacy of modern technologies like GPS, digital communication and weather forecasting. At orbital speeds, even tiny fragments can cause significant damage to operational equipment, endangering future space missions and the people who would participate in them.

“Even if a tiny, five-millimeter object hits a solar panel or a solar array of a satellite, it could break it,” says Assistant Professor Hao Chen, whose research involves space systems design. “And we have over 100 million objects smaller than one centimeter in orbit. So if you want to avoid a collision, you have to maneuver your spacecraft, which takes up fuel and is costly. Additionally, we have humans on the International Space Station who sometimes must go outside the spacecraft where the space debris can hit them too. It’s really dangerous.”

Lightning channels reveal hidden bursts: Lateral negative re-discharges observed for first time

A new study led by researchers from the Institute of Atmospheric Physics of the Chinese Academy of Sciences (CAS) has uncovered the first observational evidence of lateral negative re-discharges occurring on negative leader channels. Published recently in Geophysical Research Letters, the findings offer new insights into how lightning channels remain electrically active and how their structures evolve before and after a return stroke.

Prior to this research, negative-polarity lateral breakdowns had only been observed near the tips of positive leaders—never documented along negative leader channels.

Scientists develop a glasses-free 3D system with a little help from AI

Watching 3D movies and TV shows is a fun and exciting experience, where images leap out of the screen. To get this effect, you usually have to wear a special pair of glasses. But that could soon be a thing of the past as scientists have developed a new display system that delivers a realistic 3D experience without the need for any eyewear.

The main reason why we’ve waited so long for a screen like this is a tough physics rule called the Space-Bandwidth Product (SBP). To get a perfect 3D image, you need a big screen (the “space”) and a wide viewing area (the “bandwidth”) so the picture looks good even when you turn your head. Unfortunately, according to the rule, you can’t have both at the same time. If you make the screen big, the viewing angle shrinks. If you increase the viewing area, the TV must get smaller. All previous attempts to break this trade-off have failed. But not this time.

Classical Indian dance inspires new ways to teach robots how to use their hands

Researchers at the University of Maryland, Baltimore County (UMBC) have extracted the building blocks of precise hand gestures used in the classical Indian dance form Bharatanatyam—and found a richer “alphabet” of movement compared to natural grasps. The work could improve how we teach hand movements to robots and offer humans better tools for physical therapy.

A paper describing this work is published in the journal Scientific Reports.

Ramana Vinjamuri, a professor at UMBC and lead researcher on the work, has focused his lab on understanding how the brain controls complex hand movements. More than a decade ago, he and his research partners began searching for and cataloging the building blocks of hand motions, drawing on a concept called kinematic synergies, in which the brain simultaneously coordinates multiple joint movements to simplify complex motions.

A solid-state quantum processor based on nuclear spins

Quantum computers, systems that process information leveraging quantum mechanical effects, have the potential of outperforming classical systems on some tasks. Instead of storing information as bits, like classical computers, they rely on so-called qubits, units of information that can simultaneously exist in superpositions of 0 and 1.

Researchers at University Paris-Saclay, the Chinese University of Hong Kong and other institutes have developed a new quantum computing platform that utilizes the intrinsic angular momentum (i.e., spin) of nuclei in tungsten-183 (183 W) atoms as qubits.

Their proposed system, introduced in a paper published in Nature Physics, was found to achieve long coherence times and is compatible with existing superconductor-based quantum information processing platforms.

Frequent flares from TRAPPIST-1 could impact habitability of nearby planets

Like a toddler right before naptime, TRAPPIST-1 is a small yet moody star. This little star, which sits in the constellation Aquarius about 40 light-years from Earth, spits out bursts of energy known as “flares” about six times a day.

New research led by the University of Colorado Boulder takes the deepest look yet at the physics behind TRAPPIST-1’s celestial temper tantrums. The team’s findings could help scientists search for habitable planets beyond Earth’s solar system.

The researchers used observations from NASA’s James Webb Space Telescope and computer simulations (models) to understand how TRAPPIST-1 produces its flares—first building up magnetic energy, then releasing it to kick off a chain of events that launches radiation deep into space. The results could help scientists unravel how the star has shaped its nearby planets, potentially in drastic ways.

High-energy-density barocaloric material could enable smaller, lighter solid-state cooling devices

A collaborative research team from the Institute of Solid State Physics, the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, has discovered a high-energy-density barocaloric effect in the plastic superionic conductor Ag₂Te₁₋ₓSₓ

“This material shows a volumetric barocaloric performance far beyond that of most known inorganic materials,” said Prof. Tong Peng, who led the team, “Its high energy density makes it well-suited for smaller and lighter cooling devices.”

The findings were published online in Advanced Functional Materials.

Catalyst insight may unlock safer, on-demand ozone water disinfection

University of Pittsburgh researchers have made an important step toward providing hospitals and water treatment facilities with a safer, greener alternative to chlorine-based disinfection.

The team, which includes scientists from Drexel University and Brookhaven National Laboratory, uncovered key design principles for catalysts that can generate ozone, a disinfecting agent, on demand. The research is published in the journal ACS Catalysis.

This breakthrough addresses a critical challenge in water sanitation. Chlorine, commonly used to kill bacteria on surfaces and in water—including most municipal drinking water—is hazardous to transport and store, and its byproducts can be carcinogenic. These risks limit its use and motivate the search for safer disinfectants.

LHC data confirm validity of new model of hadron production—and test foundations of quantum mechanics

A boiling sea of quarks and gluons, including virtual ones—this is how we can imagine the main phase of high-energy proton collisions. It would seem that particles here have significantly more opportunities to evolve than when less numerous and much “better-behaved” secondary particles spread out from the collision point. However, data from the LHC accelerator prove that reality works differently, in a manner that is better described by an improved model of proton collisions.

A lot happens during high-energy proton-proton collisions. Protons are hadrons, i.e. clusters of partons—quarks and the gluons that bind them together. When protons collide with each other at sufficiently high energies, their quarks and gluons (including the virtual ones, which appear momentarily during interactions) enter into various complex interactions.

Only when they “cool down” do the quarks stick together to form new hadrons, which scatter from the collision area and are recorded in detectors. Intuition therefore suggests that the entropy of the produced hadrons—a quantity describing the number of states in which the particle system can find itself—should be different from that in the parton phase of the collision, when there are many interacting quarks and gluons, and the interactions appear at first glance to be as chaotic as they are dynamic.

A direct leap into terahertz: Dirac materials enable efficient signal conversion at room temperature

Highspeed Internet, autonomous driving, the Internet of Things: data streams are proliferating at enormous speed. But classic radio technology is reaching its limits: the higher the data rate, the faster the signals need to be transmitted.

Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have now demonstrated that weak radio signals can be efficiently converted into significantly higher frequencies using this material that is just several tens of nanometers thick. And at room temperature, at that. The results open up prospects for future generations of mobile communications and high-resolution sensor technology. The paper is published in the journal Communications Physics.

The more data to be transmitted simultaneously, the higher the carrier frequency must be. As a result, research is now delving into the terahertz range. This frequency spectrum lies outside the microwave range currently used and, so far, has been difficult to access technologically.

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