EnvironmentAre vast amounts of hydrogen fuel hidden below Earth's surface? Geologists estimate Earth contains several trillion tonnes of natural hydrogen that could be used as a clean fuel, but a global search for large reserves hasn’t delivered so far News
TechnologyTiny solar-powered drones could stay in the air forever An aerial robot weighing 4 grams is powered by tiny solar panels that produce extremely high voltages – an approach that could enable drones to fly indefinitely News