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It is difficult for me to address time as an isolated subject. I must first outline a skeleton of my own cosmological model. The cosmic foam of our universe is the ether foam of a super-universe, and the ether foam of our universe is the cosmic foam of a sub-universe. The median size bubble in our cosmic foam is roughly 10^24 meter across; the median size bubble in our ether foam is roughly 10^-35 m across. Space can be measured in ether-foam bubbles; a cubic meter is roughly 10^105 bubbles, and that number remains constant as our space expands. The expansion of our space stretches the bubble walls of our cosmic foam, causing them to pop. The same thing occurs in the sub-universe, causing its cosmic foam bubble walls to pop.
Space expands by increasing the number of ether-foam bubbles. When a wall separating two bubbles pops, two bubbles become one. That is a reduction in the number of bubbles. For the number of bubbles to increase, bubble walls must un-pop; a new wall must form across the middle of a bubble, dividing it in two. So when a cosmic-foam bubble in the sub-universe pops, one of our ether-foam bubbles must un-pop. In other words, the arrow of time reverses from one universe to the next. The expansion of space aims the arrow of time.
Turning the clock backward, we can imagine our space shrinking. This reduces the scale factor between the cosmic foam and the ether foam. Today, the factor is about 10^59 to 1. Suppose we run the clock back to a time when the scale factor was unity; we reach a time when our cosmic foam existed at the same scale as our ether foam. That could be adopted as a convenient marker for the beginning of time as we know it. Before that, the roles of cosmic foam and ether foam are reversed; the super-universe and sub-universe swap roles.
I am not saying that we CAN turn the clock back that far with any degree of confidence in what might have existed back then. If seems likely that our cosmic foam may have undergone numerous phase shifts since the beginning of time as we know it. Our cosmic foam, today, consists of bubbles surrounded by walls of galaxies. So what was it before galaxies came into existence? Did it have a foamy texture even then? I doubt if we can ever know that. Nevertheless, it does make sense to me to postulate a beginning of time as we know it, and that sets an arbitrary but finite limit to the age of our universe.
Our universe is an insignificant subset of an infinitely greater fractal universe. That greater universe exists outside of time because time runs both forward and backward within it. Time exists within the greater universe, but the greater universe has no beginning or end.