7) Let There Be Atoms!
As the forms of Atoms began to flourish out of the the photon-matter plasma, light found itself absolutely free for the first time. No longer trapped in short-sighted interactions with Electrons, it could fulfil its potential and travel along the vast open distances between atoms that now existed. The fog cleared. For the first time, the universe was transparent.
So the photons simply went headlong in all directions, speeding out in wiggly-straight lines to discover what terrain they could now zip through. Although it is quite hard to believe, some of those old, first freed photons which raced through unobstructed space way back then are still travelling today. In all those billions of years, some have not collided with even a dust-particle of matter. Stranger still, the chances are that you will have heard them playing their escape song on an crackly old radio set.
When tuning between stations, you will hear a fizzing sound made up of lots of different frequencies, which is called white noise. This can come from many sources, but a portion of the static that you hear is in fact several billion years old. It has travelled the length of the universe. It is the sound of the first photons being released.