 When they were turning the radio antenna on for the first time, they picked up this really irritating background buzz, this kind of microwave noise effectively in their instruments. A bit like turning the radio on, there's this nasty crackling static that's interfering with your piece of music. And they're like, OK, we're not going to be able to do any observations because of this noise. Penzias and Wilson spent a year trying to figure out what was causing it.