Science

A robot dog equipped with a flamethrower could be used to stop weeds growing on farms, potentially offering a replacement for harmful herbicides. Even highly targeted herbicides can cause environmental problems, affecting local wildlife, and “superweeds” are quickly evolving resistance to the most common weed-killers like glyphosate. In search of an alternative solution, Dezhen Song at Texas A&M University and his colleagues have developed a weed control system that uses a brief burst of heat from a propane-powered flamethrower controlled by a robotic arm, attached to a Spot robot manufactured by Boston Dynamics. Rather than incinerate the weeds, the robot is designed to identify and heat up the centre of the plant, which can stop it growing for se...

The 30-metre-deep assembly pit for the tokamak©enrico sacchetti Extreme in scale and ambition, this is ITER, the €20-billion energy project being built in southern France. It is set to pave the way to fusion power, akin to that which fuels the sun. Work started on the world’s biggest fusion experiment in 2006 through an international effort, including the European Union, the US, China and Russia. The first run of the reactor, during which it will create superhot matter known as plasma – a state necessary for nuclear fusion to occur – was scheduled for 2020. This was first pushed back to 2025, and fresh delays have now postponed it to 2035. Meanwhile, exclusive photographs taken by Enrico Sacchetti offer a glimpse into ITER’s construction and potential. One of the Toroi...

Installation view of David Breashears’ Mount Everest, Main Rongbuk Glacier, Tibet, China, 2007. Courtesy of Asia Society In a powerful new iteration of the “Coal + Ice” exhibit, on display at the Asia Society in New York through August 11, the immersive works of over 30 photographers highlight the causes and consequences of climate change through a people-focused lens. The show asks viewers to stare directly and unflinchingly at our changing global landscape and to reflect on how we got here. Through an interactive photographic arc, the exhibit offers a humanistic narrative of the history of climate change, beginning with portraits of coal miners, such as the one by Geng Yunsheng shown below. The exhibit then transitions into images showcasing the disappearing glacial ice across...

Shutterstock/Marko Aliaksandr Imagine if governments around the world announced restrictions on the sale of rulers that are 34 centimetres long. You would be pretty confused, given there doesn’t seem to be anything special about that length – and 34cm rulers don’t exist. Such legislation would be ludicrous, but something similar has been enacted for quantum computers in several nations (see “Multiple nations enact mysterious export controls on quantum computers“). The restrictions – which limit the export of computers with 34 or more qubits, or quantum bits, and error rates below a certain threshold – are puzzling, as such devices have no practical use, according to all published research. But the very specificity of the number suggests some thought behind it. Clearly,...

A special laser (red) can spiralise electrons (blue)Dr. Yiqi Fang, University of Konstanz An electron has been turned into a spiralling wave of mass and charge, with the help of a laser. “Chirality, or handedness, is an interesting and still in part enigmatic feature of our universe,” says Peter Baum at the University of Konstanz in Germany. Chiral objects, like coils or L-shaped blocks, come in either left or right-handed forms; non-chiral ones, like circles or straight lines, do not. Many molecules and materials are naturally chiral, and whether they are right or left-handed changes how they function. But Baum and his colleagues devised a way to add chirality to something very small and elementary – a single electron. Electrons are quantum objects, so they exhib...