Tiny ocean organisms living in oxygen-poor waters turn nutrients into nitrous oxide—a greenhouse gas far more powerful than carbon dioxide—via complex chemical pathways.

Penn’s Xin Sun and collaborators identified the how and why behind these chemical reactions, showing that microbial competition, not just chemistry, determines how much N₂O is produced.

Their findings pave the way for more reliable climate models, making global greenhouse gas estimates more effective, predictable, and easier to understand in response to natural and man-made climate change.

In this week’s AIP Advances, researchers explore gemstone polishing waste as a possible additive in cement, aiming to keep silicon carbide waste out of landfills and reduce emissions from the cement industry. The team tested chemical reactions at the molecular level, as well as microscale characteristics, such as microcracks and pore size, and macroscale outcomes, such as material strength and thermal and conductive properties. The added gemstone polishing waste enhanced thermal conductivity and reduced electrical resistivity in the modified cement.

Current battery management systems might report a car is 40% charged but drivers have to guess whether they can go 100 kilometers over hills with the heater running. Engineers at the University of California, Riverside want to take the guesswork out of it.

MIT scientists developed a method to predict how plasma in a tokamak fusion machine will behave during a rampdown, when the reactor’s plasma current is shut off. The research could improve the safety and reliability of future fusion power plants. 

For years, researchers have puzzled over how the ancient people of Rapa Nui did the seemingly impossible and moved their iconic moai statues. Using a combination of physics, 3D modeling and on-the-ground experiments, a team including faculty at Binghamton University, State University of New York, has confirmed that the statues actually walked – with a little rope and remarkably few people.

An international team of researchers has developed a novel technique to efficiently excite and control highly-confined light-matter waves, known as higher-order hyperbolic phonon polaritons (HPhPs). Their method not only sets new records for the quality and propagation distance of these waves but also uses a sharp boundary to create a form of pseudo-birefringence, sorting and steering the waves by mode into different directions. This breakthrough, published in Nature Photonics, opens new avenues for developing nanoscale optical devices for high-speed signal processing and ultra-sensitive chemical detection. The full study is available at: https://www.nature.com/articles/s41566-025-01755-5