Cosmic Background Radiation 

During the early stages of the Big Bang while immense amount of energy gave raise to the free floating subatomic particles in this still greatly dense sphere, during this time the conditions still did not provide an ideal setting for nuclear fusion of neutral atoms. These charged subunits emitted large amounts of radiation and photon particles (light) which continued until the temperature cooled enough to make neutral atoms which no longer could absorb the thermal radiation emissions. The radiation and photons that existed during this time period began to move freely through space no longer contained within the region and as well expanded throughout our universe. In 1964, two radio astronomers Arno Penzias and Robert Wilson discovered this now uniform thermal radiation accidentally trying to get rid of a constant background “noise” from their radio antenna signals, they later realize that this constant signal was uniform in every direction and that it must have originated far far away, which meant a very long time ago. This detectable form of microwaves was called Cosmic Background Radiation, a much weaker form of radiation due to the lengthening of the wavelength. This radiation is detectable allover the universe and has no correlation with stars, plants or anything else which leads scientist to believe that this is in fact remanence of the early radiation emitted 13.7 billion years ago during the Big Bang.