TechnologyWhy curbing chatbots' worst exploits is a game of whack-a-mole AI companies are trying to impose safety measures on their chatbots, while researchers are finding ways around them all the time. Where will this end, asks Alex Wilkins Comment
EnvironmentThe gold hydrogen rush: Does Earth contain near-limitless clean fuel? Prospectors around the world are scrambling to find reserves of "gold hydrogen", a naturally occurring fuel that burns without producing carbon dioxide. But how much is really out there and how easy is it to tap into? Features