There is nothing in theory or our concept of reality mandating a beginning.
This is why AWT doesn't considers the beginning of Universe. It simply doesn't need concept of origin (which brings only questions for another origin and it explains nothing in fact).
The picture above illustrates the light spreading in vacuum by splash ripples at the water surface. These ripples gradually decays and increase their frequency from outer perspective. From inside perspective (i.e. the perspective of observer sitting at the water surface and observing space-time formed by its waves) the perspective would became exactly as opposite. He would see expanding space in omnidirectional way and waves ending their life in background noise in remote distance. He can still interpret such observation as a Big Bang event - but the another, remote observer would see exactly the same thing at the place of first observer!
Bellow is picture of
Hubble ultradeep field at the moment, when Universe was just only 5 percent of its present age. Despite of this, we still cannot see any evidence of Universe evolution there - only separated huge galaxies, which are apparently quite well developed and old.
