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Reçu aujourd’hui — 10 janvier 2026 6.5 📰 Sciences English
Reçu hier — 9 janvier 2026 6.5 📰 Sciences English

Watching how grasshoppers glide inspires new flying robot design

9 janvier 2026 à 15:43

While much insight has been gleaned from how grasshoppers hop, their gliding prowess has mostly been overlooked. Now researchers at Princeton University have studied how these gangly insects deploy and retract their wings to inspire a new approach to flying robots.

Typical insect-inspired robot designs are often based on bees and flies. They feature constant flapping motion, yet that requires a lot of power so the robots either carry heavy batteries or are tethered to a power supply.

Grasshoppers, however, are able to jump and glide as well as flap their wings and while they are not the best gliding insect, they have another trick as they are able to retract and unfurl their wings.

Grasshoppers have two sets of wings, the forewings and hindwings. The front wing is mainly used for protection and camouflage while the hindwing is used for flight. The hindwing is corrugated, which allows it to fold in neatly like an accordion.

A team of engineers, biologists and entomologists, analysed the wings of the American grasshopper, also known as the bird grasshopper, due to its superior flying skills. They took CT scans of the insects and then used the findings to 3D-print model wings. They then attached the wings to small frames to create grasshopper-inspired gliders finding that their performance was on par with that of actual grasshoppers.

They also tweaked certain wing features such as the shape, camber and corrugation, finding that a smooth wing actually produced gliding that was more efficient and repeatable than one with corrugations. “This showed us that these corrugations might have evolved for other reasons,” notes Princeton engineer Aimy Wissa, who adds that “very little” is known about how grasshoppers deploy their wings.

The researchers say that further work could result in new ways to extend the flight time for insect-sized robots without the need for heavy batteries of tethering. “This grasshopper research opens up new possibilities not only for flight, but also for multimodal locomotion,” adds Lee. “By combining biology with engineering, we’re able to build and ideate on something completely new.”

The post Watching how grasshoppers glide inspires new flying robot design appeared first on Physics World.

The Space Force will acquire and integrate systems faster in 2026

9 janvier 2026 à 15:00

At the beginning of 2026, it’s worth reflecting on the U.S. Space Force’s recent accomplishments. They include the creation of the Commercial Space Office and its Commercial Augmentation Space Reserve, a working capital fund to provide flexibility in providing MILSATCOM services and new acquisition approaches for Resilient GPS and Protected Tactical SATCOM. The list of […]

The post The Space Force will acquire and integrate systems faster in 2026 appeared first on SpaceNews.

Cracking the limits of clocks: a new uncertainty relation for time itself

9 janvier 2026 à 13:00

What if a chemical reaction, ocean waves or even your heartbeat could all be used as clocks? That’s the starting point of a new study by Kacper Prech, Gabriel Landi and collaborators, who uncovered a fundamental, universal limit to how precisely time can be measured in noisy, fluctuating systems. Their discovery – the clock uncertainty relation (CUR) – doesn’t just refine existing theory, it reframes timekeeping as an information problem embedded in the dynamics of physical processes, from nanoscale biology to engineered devices.

The foundation of this work contains a simple but powerful reframing: anything that “clicks” regularly is a clock. In the research paper’s opening analogy, a castaway tries to cook a fish without a wristwatch. They could count bird calls, ocean waves, or heartbeats – each a potential timekeeper with different cadence and regularity. But questions remain: given real-world fluctuations, what’s the best way to estimate time, and what are the inescapable limits?

The authors answer both. They show for a huge class of systems – those described by classical, Markovian jump processes (systems where the future depends only on the present state, not the past history – a standard model across statistical physics and biophysics) – there is a tight achievable bound on timekeeping precision. The bound is controlled not by how often the system jumps on average (the traditional “dynamical activity”), but by a subtler quantity: the mean residual time, or the average time you’d wait for the next event if you start observing at a random moment. That distinction matters.

The inspection paradox
The inspection paradox The graphic illustrates the mean residual time used in the CUR and how it connects to the so-called inspection paradox – a counterintuitive bias where randomly arriving observers are more likely to land in longer gaps between events. Buses arrive in clusters (gaps of 5 min) separated by long intervals (15 min), so while the average time between buses might seem moderate, a randomly arriving passenger (represented by the coloured figures) is statistically more likely to land in one of the long 15-min gaps than in a short 5-min one. The mean residual time is the average time a passenger waits for their bus if they arrive at the bus stop at a random time. Counterintuitively, this can be much longer than the average time between buses. The visual also demonstrates why the mean residual time captures more information than the simple average interval, since it accounts for the uneven distribution of gaps that biases your real waiting experience. (Courtesy: IOP Publishing)

The study introduces CUR, a universal, tight bound on timekeeping precision that – unlike earlier bounds – can be saturated and the researchers identify the exact observables that achieve this limit. Surprisingly, the optimal strategy for estimating time from a noisy process is remarkably simple: sum the expected waiting times of each observed state along the trajectory, rather than relying on complex fitting methods. The work also reveals that the true limiting factor for precision isn’t the traditional dynamical activity, but rather the inverse of the mean residual time. This makes the CUR provably tighter than the earlier kinetic uncertainty relation, especially in systems far from equilibrium.

The team also connects precision to two practical clock metrics: resolution (how often a clock ticks) and accuracy (how many ticks before it drifts by one tick.) In other words, achieving steadier ticks comes at the cost of accepting fewer of them per unit of time.

This framework offers practical tools across several domains. It can serve as a diagnostic for detecting hidden states in complex biological or chemical systems: if measured event statistics violate the CUR, that signals the presence of hidden transitions or memory effects. For nanoscale and molecular clocks – like biomolecular oscillators (cellular circuits that produce rhythmic chemical signals) and molecular motors (protein machines that walk along cellular tracks) – the CUR sets fundamental performance limits and guides the design of optimal estimators. Finally, while this work focuses on classical systems, it establishes a benchmark for quantum clocks, pointing toward potential quantum advantages and opening new questions about what trade-offs emerge in the quantum regime.

Landi, an associate professor of theoretical quantum physics at the University of Rochester, emphasizes the conceptual shift: that clocks aren’t just pendulums and quartz crystals. “Anything is a clock,” he notes. The team’s framework “gives the recipe for constructing the best possible clock from whatever fluctuations you have,” and tells you “what the best noise-to-signal ratio” can be. In everyday terms, the Sun is accurate but low-resolution for cooking; ocean waves are higher resolution but noisier. The CUR puts that intuition on firm mathematical ground.

Looking forward, the group is exploring quantum generalizations and leveraging CUR-violations to infer hidden structure in biological data. A tantalizing foundational question lingers: can robust biological timekeeping emerge from many bad, noisy clocks, synchronizing into a good one?

Ultimately, this research doesn’t just sharpen a bound; it reframes timekeeping as a universal inference task grounded in the flow of events. Whether you’re a cell sensing a chemical signal, a molecular motor stepping along a track or an engineer building a nanoscale device, the message is clear: to tell time well, count cleverly – and respect the gaps.

The research is detailed in Physical Review X.

The post Cracking the limits of clocks: a new uncertainty relation for time itself appeared first on Physics World.

The U.S. will seize space leadership – or China will take it

9 janvier 2026 à 13:00
It was a record launch year for China, and the country shows no sign of slowing down in 2026. Credit: CASC; Ourspace; Landspace

America faces a choice in space: lead or follow. There’s no middle ground anymore. China is methodically executing a plan to dominate the moon and cislunar space. The question isn’t whether someone will control humanity’s next economic frontier — it’s whether that someone will be us or them. And if we want it to be […]

The post The U.S. will seize space leadership – or China will take it appeared first on SpaceNews.

Bidirectional scattering microscope detects micro- and nanoscale structures simultaneously

9 janvier 2026 à 11:00

A new microscope that can simultaneously measure both forward- and backward-scattered light from a sample could allow researchers to image both micro- and nanoscale objects at the same time. The device could be used to observe structures as small as individual proteins, as well as the environment in which they move, say the researchers at the University of Tokyo who developed it.

“Our technique could help us link cell structures with the motion of tiny particles inside and outside cells,” explains Kohki Horie of the University of Tokyo’s department of physics, who led this research effort. “Because it is label-free, it is gentler on cells and better for long observations. In the future, it could help quantify cell states, holding potential for drug testing and quality checks in the biotechnology and pharmaceutical industries.”

Detecting forward and backward scattered light at the same time

The new device combines two powerful imaging techniques routinely employed in biomedical applications: quantitative phase microscopy (QPM) and interferometric scattering (iSCAT).

QPM measures forward-scattered (FS) light – that is, light waves that travel in the same direction as before they were scattered. This technique is excellent at imaging structures in the Mie scattering region (greater than 100 nm, referred to as microscale in this study). This makes it ideal for visualizing complex structures such as biological cells. It falls short, however, when it comes to imaging structures in the Rayleigh scattering region (smaller than 100 nm, referred to as nanoscale in this study).

The second technique, iSCAT, detects backward-scattered (BS) light. This is light that’s reflected back towards the direction from which it came and which predominantly contains Rayleigh scattering. As such, iSCAT exhibits high sensitivity for detecting nanoscale objects. Indeed, the technique has recently been used to image single proteins, intracellular vesicles and viruses. It cannot, however, image microscale structures because of its limited ability to detect in the Mie scattering region.

The team’s new bidirectional quantitative scattering microscope (BiQSM) is able to detect both FS and BS light at the same time, thereby overcoming these previous limitations.

Cleanly separating the signals from FS and BS

The BiQSM system illuminates a sample through an objective lens from two opposite directions and detects both the FS and BS light using a single image sensor. The researchers use the spatial-frequency multiplexing method of off-axis digital holography to capture both images simultaneously. The biggest challenge, says Horie, was to cleanly separate the signals from FS and BS light in the images while keeping noise low and avoiding mixing between them.

Horie and colleagues, Keiichiro Toda, Takuma Nakamura and team leader Takuro Ideguchi, tested their technique by imaging live cells. They were able to visualize micron-sized cell structures, including the nucleus, nucleoli and lipid droplets, as well as nanoscale particles. They compared the FS and BS results using the scattering-field amplitude (SA), defined as the amplitude ratios between the scattered wave and the incident illumination wave.

“SA characterizes the light scattered in both the forward and backward directions within a unified framework,” says Horie, “so allowing for a direct comparison between FS and BS light images.”

Spurred on by their findings, which are detailed in Nature Communications, the researchers say they now plan to study even smaller particles such as exosomes and viruses.

The post Bidirectional scattering microscope detects micro- and nanoscale structures simultaneously appeared first on Physics World.

The Oceans Just Keep Getting Hotter

9 janvier 2026 à 09:00
For the eighth year in a row, the world’s oceans absorbed a record-breaking amount of heat in 2025. It was equivalent to the energy it would take to boil 2 billion Olympic swimming pools.

Reçu — 8 janvier 2026 6.5 📰 Sciences English
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