Time

Considering time as a 4th dimension of existence has its consequences.
The fabric of the universe, that is, the structure in which everything exists, pre-exists to any such a thing. I know that something exists a mile from me in some direction, regardless of my ability to sense it, merely because the space coordinates extend to that point. I know that something exists 10 minutes from now and I only need 10 minutes to prove it.
Moreover, it is invariant, meaning that it is the perception of the observer about the universe that is subject to change, not only relative to other observers (relativity) but also relative to the same observer in different circumstances.
So, if time is a dimension of this structure, then all past events and all future events are “happening” as much as the present ones, because they lack none of the 4 dimensions required for existence. They still locate themselves at some space coordinate system and a moment in time.
Therefore, it would be the case that it is not time that flows but instead it is the observer who measures time who moves relative to the time(-space) coordinate, and even more, since every observer has a measure of the passage of time that does not depend on his will, then it is not the observer that is in motion but something fundamental to the observer.
If we accept that we could have made different choices in the past, then all possible past events exist and consequently all possible future events exist, not just one. This in turn would require at least a 5th dimension to the universe to distinguish between different events at the same place and at the same time.
The invariant aspect of that motion, the law of this motion, is more elementary than the observers of the motion.
The act of measuring time is itself a perspective of, or a motion in, the universe, and in this regard consistent with the Liebniz concept of Monad — both a perspective of the universe and the universe under a particular perspective.