
Pigeon droppings nearly obscured the discovery of the cosmic microwave background
In 1965, Bell Labs engineers Arno Penzias and Robert Wilson identified the cosmic microwave background radiation while troubleshooting a persistent noise in a 20-foot horn antenna in Holmdel, New Jersey. After removing pigeon droppings and ruling out equipment errors, they realized the signal was uniform background heat from the Big Bang, confirming a theory predicted by Princeton physicist Robert Dicke.

