Step-by-step explanation:
The two teams involved in the discovery of the cosmic microwave background (CMB) radiation were:
1. Bell Labs team led by Arno Penzias and Robert Wilson: In 1964, Arno Penzias and Robert Wilson were conducting experiments at Bell Labs in Holmdel, New Jersey, in the United States. They were working with a large horn antenna intended for satellite communication but were puzzled by a persistent background noise that they couldn't eliminate. After ruling out various possible sources of interference, including pigeon droppings in the antenna, they realized that the noise they were detecting was coming from all directions in the sky. Eventually, they identified it as the CMB radiation, which is a remnant of the Big Bang and fills the entire universe.
2. Princeton University team led by Robert Dicke and Jim Peebles: At the same time, a team of scientists at Princeton University in New Jersey, also in the United States, led by Robert Dicke, was independently working on the theory and detection of the CMB radiation. They were motivated by the idea that if the Big Bang had occurred, there should be residual radiation left over from that event. Dicke and his team were developing a sensitive microwave receiver called a Dicke radiometer to detect this radiation. While they were still in the process of constructing their instrument, they learned about the discovery made by Penzias and Wilson. Dicke and his colleague Jim Peebles had predicted the existence of the CMB radiation as part of their work, and the discovery by Penzias and Wilson provided strong confirmation of their theory.
Both teams made significant contributions to the discovery of the CMB radiation, and their work helped establish the Big Bang theory as the leading explanation for the origin of the universe. In recognition of their groundbreaking discovery, Penzias and Wilson were awarded the Nobel Prize in Physics in 1978, while Dicke, Peebles, and two other scientists involved in related research, P. J. E. Peebles and R. W. Henry, received the 2019 Nobel Prize in Physics.