The Real Creation Story...
There was nothing. It was cold and dark. Nothing exists, so the space is truly infinite. That is the characteristic of nothing, the great cold dark void of non existence.
The time was before t=0, if real time even existed. Conceptual orthogonal time always exists, as much as any concept exists. All the force were one and none, it was just too cold to exist. There was no matter, as the temperature was absolute zero. It is essential to understand the conditions that existed before t=0, for these are unstable conditions. It was dark because no photons existed. It was too cold for matter to exist, as it was too cold for the forces to exist.
In everything there is a bit of natural variation. It is next to impossible to fine something without natural variation. One bit of the infinite space varied slightly in temperature, the four forces split, and all shit broke loose. The reaction is spontaneous and exothermic. It cannot be stopped once it starts. After that bit of variation, a universe was inevitable. What that universe looks like is, well, it might as well be random, because there are so many variations possible. And now, some 13.8 billion years later, we have a radiation bubble, some 13.8 billion light years in radius, and growing, floating in infinite space. There maybe other bubbles out there, we cannot know with today's information, or not.
There was no bang, as there was no atmosphere. Space itself splits into matter. It would have been a flash, but there was more radiation than flash. Quirks, quarks, bosons, fermions, leptons all spinning in integer ways to form hot plasma, combining to form electrons, neurons, protons. At the edges Hydrogen and Helium, perhaps a touch of lithium form, with mass and are forced outward at slightly less than the speed of light as mass has come into being. It is a spontaneous and exothermic reaction, driving itself outward, it cannot be stopped now. It grows without plan, without purpose, without meaning, without any control. It is spontaneous and growing.
Expansion has continued now for some 13.8 billion years, measured backward, after the year was developed on this lonely planet. We lie somewhere in the middle 1/3 of this massive radiation bubble, that we can just measure... well sort of, now. We animals have developed, and learned to build machines that are able to scene the radiation, just. So now, how long do we have before we destroy our own atmosphere by overgrowth?