Here we can see an image of the timeline of our Universe. Look at the left side and you can SEE the subatomic Flow and the Plank time that occurred immediately after the Big Bang. Notice that the afterglow LIGHT pattern emerged 400,000 years after the Big Bang.
The green sliver is the Cosmic Background Radiation.
Several satellite systems together determined that the difference from the warmest to the coldest readings of the elements in the Cosmic Background Radiation is .000018 Kelvin ^.
Roger Hawkings called this the greatest discovery in Science because it gave the Universe a differential that gave birth to Galaxies and the Solar system and life and us.