Reading by the light of a lamp floating in mid-air might be something you’d only see in Harry Potter movies. But as it turns out, such a lamp really does exist. The lamp was designed by a Swiss company, and the technology behind it is similar to that used by drones (无人机). There are propellers (螺旋桨) inside the lamp to help it fly. And the shape of the lamp was inspired by rocket nozzles (火箭喷嘴), not only giving the lamp a lot of thrust (推力), but also allowing it to keep its balance while floating.