Physicists have demonstrated a laser-based method that enables a cryogenic electron microscope to image small protein structures with greater detail than previously possible.
Category: physics
Astrochemical model digs into the universe’s missing sulfur
Sulfur is one of the most abundant elements in the universe. If you peer into a diffuse interstellar cloud, you find loads of it—about the amount expected based on fusion patterns in the stars it was born in. However, if you look at a dense, cold molecular cloud—the kind where those stars actually form—it seems like 99% of the sulfur expected to be there is missing. Scientists have puzzled over this “missing sulfur problem” for decades, though a leading theory is that the element hides in icy dust grains, making it hard to detect.
A new paper published in Astronomy & Astrophysics from the Max Planck Institute for Extraterrestrial Physics and the Centro de Astrobiologia describes a new computer simulation model aimed at supporting the interpretation of laboratory results and testing our current understanding of sulfur evolution in interstellar ices.
The simulation was written in pyRate—a Python-based application that calculates how chemicals interact, especially between ice and gas phases. The paper marks the first successful model of the chemistry of a multicomponent interstellar ice analog with a rate-equation simulation. Scientists love “firsts,” but what does that actually mean in practice in this case?
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Room-temperature laser hits record stability with 68-cm optical cavity
Scientists at NPL have demonstrated the best-reported laser frequency stability achieved with an optical reference cavity operating at room temperature, marking a major advance in ultrastable laser technology. The team’s results have been published in Optica.
Ultrastable lasers produce light of exceptional spectral purity and are a critical enabling technology for optical atomic clocks. These are the next generation of atomic clocks based on atomic transitions in the optical domain. These clocks underpin the most precise timekeeping ever achieved and are central to future technologies ranging from advanced navigation to fundamental physics.
The NPL team measured a fractional frequency instability of 4 × 10⁻¹⁷, achieved for the first time using a room-temperature optical reference cavity. Until now, comparable performance had only been realized internationally using complex cryogenic systems.
‘Collapsible scissored surfaces’ complete trilogy of metamaterial design principles
Over the past decade, Professor L. Mahadevan’s Soft Math Lab at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) has helped establish how the ancient Japanese paper arts of folding or cutting can be used to inversely design structures that transform dramatically in shape and function. Now, the researchers have created a new class of shape-changing matter, based not on folds or cuts, but linkages—networks of interconnected scissor mechanisms that collapse into lines and deploy into curved surfaces.
The study published in the Proceedings of the National Academy of Sciences, led by physics graduate student Noah Toyonaga, establishes a mathematical and physical framework for what the authors call collapsible scissored surfaces—deployable lattices of two-bar linkages that can transform from a one-dimensional collapsed state into two-dimensional structures with prescribed geometry.
“Origami showed how folds can encode shape,” said senior author Mahadevan, the Lola England de Valpine Professor of Applied Mathematics, of Organismic and Evolutionary Biology, and of Physics. “Kirigami showed how cuts can unlock motion and functionality. This work asks a complementary question: What can be achieved when the basic building block is not a fold or a cut, but a linkage?”
Geometric anti-spring works near absolute zero, suppressing vibrations below 0.185 hertz
Physicists and instrument makers in Leiden have succeeded in optimizing a spring that almost completely filters out vibrations at temperatures near absolute zero. This breakthrough opens the door to a new generation of highly sensitive experiments. The research is published in the journal Measurement Science and Technology.
“Our new special spring reduces the disruptive vibrations down to 0.185 hertz, which is a major improvement,” says Ph.D. candidate Louw Feenstra. Instrument makers Kees van Oosten and Hugo van Bohemen designed and built the new instrument in their workshop and tested it in the lab together with Feenstra.
Today, many—if not all—modern physics experiments are based on extremely precise measurements. Such measurements are often carried out inside a cryostat, a device that cools materials to temperatures as close as possible to absolute zero (0 Kelvin equals −273.15°C). Until now, cryostats had one major drawback: Their cooling systems generate strong vibrations, particularly around 1 hertz—roughly one vibration per second. For sensitive experiments, this can seriously affect the results.
Dimension Zero LIVE #1 | Science, Sci-Fi, Physics, Star Trek, Supergirl & More
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Dimension Zero explores The Science of Science Fiction, separating scientific fact from fiction while celebrating the worlds we love.
Espresso ‘pucks’ stop behaving predictably above certain pressures
When a physics student asked baristas at the Warsaw Coffee Conference what their biggest question for scientists was, the baristas said they wanted to know how to stop channeling during brewing.
Channeling is an issue that arises as hot water passes through a pressed “puck” of espresso. The water follows the path of least resistance through the coffee grounds, resulting in an uneven brew and bitter flavor.
In Physics of Fluids, researchers from the University of Warsaw set out to determine the physical properties of espresso brewing to improve the preparation process.
New breakthrough spots deadly methanol without opening bottles
A new optical technique developed by researchers at the University of St Andrews and Adelaide University allows toxic methanol in alcoholic spirits to be detected without opening the bottle. Published in the Journal of Physics: Photonics, this new work offers a powerful new tool for tackling counterfeit alcohol and improving consumer safety worldwide.
Methanol contamination of spirits such as whiskey, gin and vodka causes hundreds of deaths each year and can lead to serious physical consequences, such as blindness. Recent high-profile incidents have highlighted the danger: In 2024, six tourists died in Laos after drinking alcohol later found to be contaminated with methanol. It is estimated that methanol poisoning has caused tens of thousands of deaths globally, with incidents documented in nearly 80 countries.
Despite this, gold-standard tests for methanol detection are time-consuming and expensive, requiring trained personnel and specialized laboratory equipment.
Room-temperature device synchronizes distant laser spots into single coherent ‘supermode’
Researchers have demonstrated a new way to make spatially separated lasers synchronize and act as a single coherent light source—without extreme conditions or complex materials.
A team of physicists from the University of Southampton (UK), University of Warsaw (PL), Military University of Technology (PL), Institut Pascal, Université Clermont Auvergne, CNRS (FR), and CNR (IT) has developed a new class of tunable photonic devices in which multiple tiny laser beams spontaneously synchronize and behave as a unified, spatially extended and coherent light source. Remarkably, this effect is achieved at room temperature using a simple system based on liquid crystals and organic dye molecules, opening new possibilities for low-cost and reconfigurable optical technologies.
The work is published in the journal Nature Communications. The study demonstrates that spatially separated laser spots inside an optical microcavity can spontaneously phase-lock—that is, align (or synchronize) their oscillations—and form a collective state known as a “supermode.” Traditionally, such behavior has been observed only in highly specialized semiconductor systems operating at cryogenic temperatures and in the so-called strong light-matter coupling regime.