Scientists Confounded by Radio Burst Discover It’s Just The Microwave
FRBs are “fast radio bursts,” and scientists use radio telescopes to discover them. FRBs usually come from space, at least the ones that scientists are interested in, but sometimes they come from the lunch room.
Around 1998, the Parkes Observatory started noticing FRBs that they couldn’t quite explain. They seemed to come from an earthly source, but no one could figure out where.
Someone dubbed these FRBs Preytons, after the mythical creature that casts the shadow of a human.
Long story short, after installing radio wave sensors, they discovered the origin was the lunch room microwaves! When you open the door of a microwave before it has fully shut down, it emits a brief burst of radio waves.
Source: Identifying the source of perytons at the Parkes radio telescope