In the mid-1960s, two astronomers named Arno Penzias and Robert Wilson decided that they wanted to map signals from the Milky Way, using an extremely large antenna to pick up the signals. To their frustration, instead of receiving short, distinct radio signals, all that they could hear was a constant hum that blocked out any other noise.
Ruling out any kind of extra-terrestrial life, the researchers attempted to discover where else the noise could be coming from. Tests ruled out noise from nearby New York City, or any kind of military testing taking place nearby. Frustrated, the two could not figure out where else this white-noise could be coming from. As a last-ditch effort, after discovering pigeon droppings on and nearby the antenna, Penzias and Wilson decided that the only other possible explanation for the disruption of the antenna signal was pigeons.
After attempting to scare away the birds, the researchers decided that their only other option was to commit a pigeon massacre. According to Penzias, “To get rid of them, we finally found the most humane thing was to get a shot gun…and at very close range [we] just killed them instantly. It’s not something I’m happy about, but that seemed like the only way out of our dilemma.”
Yet the serial pigeon homicide did nothing to remove the humming noise from the antenna. So the only other option was that this long, constant signal was actually coming from outer space, and may possibly have a significant meaning.
Around this same time, physicist Robert Dicke of Princeton University had noted the likelihood that, if an event such as the Big Bang had occurred, low level radiation would be dispersed throughout the entire universe. Hearing this, Penzias and Wilson made the connection between their incessant buzzing noise and Dicke’s prediction. Thus, by accident, these two researchers discovered distinct proof of the Big Bang Theory.
Penzias and Wilson's discovery won them the Nobel Prize in Physics in 1978. While the idea had been around since the 1920s, this was one of the first events in which a concrete support of the theory had been discovered. Penzias’ and Wilson’s accidental discovery advanced study of the Big Bang by a giant leap, allowing other scientists to continue more advanced work on the subject.
According to sites.psu.edu