Science

Ekkehard Peik is a clock-maker. But instead of spending his days looking at tiny cogs and springs through a magnifying glass, the tools of his trade are powerful lasers, wires and, occasionally, radioactive atoms. Peik, director of the German metrology institute (PTB), is one of a handful of physicists who have spent the best part of three decades trying to make the most accurate timepiece in the universe. Since the 1950s, researchers have been constructing atomic clocks, the very best of which are now so accurate they only lose a second in around 31 billion years. But these are about to be replaced by a new model: the nuclear clock. This promises to outperform its atomic counterparts both in terms of precision and accuracy. A nuclear clock would, in principle, only d...

During the summer of 2022, I was part of a 16-member crew doing trail maintenance in California’s Trinity Alps. The job required us to live in tents and work outside. For several days, smoke from three different forest fires in the region had been burning our throats and giving us headaches, despite the masks we wore. Finally, one morning our supervisor stood in front of us, holding back tears because the forest he loved was burning so intensely. “You have to go; it’s not safe,” he said. Two years later, in 2024, the Park Fire blazed across acres of forest three hours south of where my crew had been evacuated, belching smoke into areas miles away from the burn site. Over 400,000 acres of forest burned and over 600 structures have been destroyed by the fire, according to CalFire. ...

Many AI-generated images look realistic until you take a closer lookMidJourney Did you notice that the image above was created by artificial intelligence? It can be difficult to spot AI-generated images, video, audio and text at a time when technological advances are making them increasingly indistinguishable from much human-created content, leaving us open to manipulation by disinformation. But by knowing the current state of the AI technologies used to create misinformation, and the range of telltale signs that what you are looking at might be fake, you can help protect yourself from being taken in. World leaders are concerned. According to a report by the World Economic Forum, misinformation and disinformation may “radically disrupt electoral processes in several ec...

Polarised light can make messages encoded in a quantum hologram disappearHong Liang, Wai Chun Wong, Tailin An, Jensen Li 2024 A quantum disappearing act could make it possible to embed secure messages in holograms and selectively erase parts of them even after they have been sent. Quantum light signals are inherently secure information carriers, as intercepting their messages destroys fragile quantum states that encode them. To take advantage of this without having to use bulky devices, Jensen Li at the University of Exeter in the UK and his colleagues used a metasurface, a 2D material engineered to have special properties, to create quantum holograms. Holograms encode complex information that can be recovered when illuminated – for instance, a 2D holographic pape...

Pong is a simple video gameINTERFOTO/Alamy An inanimate glob of ion-laced jelly can play the computer game Pong and even improve over time. Researchers plan further experiments to explore whether it can handle more complex computations and hope it could eventually be used to control robots. Inspired by previous research that used brain cells in a dish to play Pong, Vincent Strong and his colleagues at the University of Reading, UK, decided to try playing the tennis-like game with an even simpler material. They took a polymer material containing water and laced it with ions to make it responsive to electrical stimuli. When electricity is passed through the material, those ions move to the source of the current, dragging water with them and causing the gel to swell. ...