At any given moment invisible information is traveling all around you. There are two obvious examples: radio waves…or if you’re listening online, the wireless signal emitted by your router. Researchers at MIT have been experimenting with these signals and they’ve developed a type of radar that uses Wi-Fi signal that can be seen – and used to detect movement and even see through walls. Dina Katabi, is a professor of electrical engineering and computer science at MIT, and she spoke with us about her new project, what she’s calling “Wi-Vi.”