While testing the The Holmdel Horn Antenna in New Jersey in 1965, a constant background radiation of 3.5 Kelvin was discovered in every direction the telescope was aimed. The scientist assumed there was a fault in the equipment, they went to the extremes of covering their giant Horn Radio Telescope in foil and removing every trace of bird droppings from this giant instrument.
Still the telescope continued to pickup a background radiation reading of 3.5K, no matter where the telescope was aimed.
This is believed to be residual radiation from the Big Bang, the creation of the universe itself, some 15 billions years ago. This episode of NOVA traces this discovery and how it may help confirm Albert Einstein's General Theory of Relativity.
