I do not remember ever distinguishing the dimensions of space—length, depth, width, breadth, height—from time. Edgar Allan Poe, H.G. Wells, and even Marcel Proust wrote of space and time as one. I came late to the word space-time (or spacetime) but not to the concept, not really.
For me, space-time has always been more about mindfulness, paying attention to the details of life as they unfold. The space of a moment is a combination of any three of the spatial dimensions–width, depth, breadth, length, or height. Its time is its unfolding as a scene in life. It is as if each moment has four dimensions, a trio of space in time, 3+1.
Space-time gives me a better sense of the present as a bridge between the past and the future. The present provides open-ended access to both yet serves as a reminder that the only time we actually live is now.
Having access to the past and to the future is not the same as being in either for we are always only in the present. Yet, it is in paying attention to the details of our lives as they unfold that provides the access to both the past and to the future.
If being completely immersed in the moment reminds us of a similar scenario, that past moment might flash through the mind. It usually does for me. In that flash of familiarity, I have accessed the immutable past but the present scene is of its own unfolding. The scenes are similar but not the same.
Awareness also seems to color the future. Sometimes, I wonder whether or not awareness is the source of infinite possibilities. When we are truly present maybe we are stockpiling for our future; perhaps by minding the details of the present, we provide options for the future.
It is tempting to try to re-create the past as well as frame the future, as if either were possible. Neither is. I know. I have tried. The present is all there ever is and to ignore it is like separating space from time, something I cannot do.
After all, everywhere I go, there I am. I might as well be who I am in the moment that I am.