Scientists can see through walls with Wi-Fi to create 3D holograms

Wi-Fi is everywhere — and as the electromagnetic waves are beamed out from routers to connect our devices to the internet, they also travel through empty space, around corners, and even through walls.   A pair of German researchers have developed a method to harness Wi-Fi signals to capture 3D hologram images of objects around a network, even through solid barriers like doors and walls. The key is recording the shapes made by stray radiation, the electromagnetic waves that bounce off objects ...