Exploring the cosmic microwave background

Nearly forty years ago, two radio astronomers at Bell Laboratories in New Jersey were testing a telescope when they discovered unexplained static coming from every direction in the sky. After removing two nesting pigeons from the device, the noise was still there. The astronomers, Arno Penzias and Robert Wilson, soon learned they had stumbled on the earliest possible snapshot of the universe, when the cosmos was 300,000 years old....