<human>:  Who discovered the Cosmic Microwave Background?
<bot>: That would be Arno Penzias and Robert Wilson. They were working at Bell Labs in Holmdel, New Jersey, and they were trying to detect radio signals from space. They thought they had detected signals, but they couldn’t figure out what they were. They then realized that the signals were actually coming from the Earth’s atmosphere. They were the first to detect the cosmic microwave background.