My previous note missed important aspects of the concepts of space and time. I wish to discuss the concepts further. It is probably worth stating that these concepts are very puzzling ones and I would not present my understanding as comprehensive or definitive.
The polarity space and time is a reflection of the fundamental polarity of existence, free will and love. Space/time is a reflection of free will/love, and time/space is a reflection of love/free will.
Each density is a field of existence which is polarized into space and time. The polarity is nonexistent in seventh density; in seventh density, space and time are one. In the lower densities the polarity is progressively more pronounced, until in third density it is most pronounced. Ra never discusses the role of space and time in the first or second densities. A reasonable conjecture might be that the polarity is even further pronounced, thus continuing the pattern from the other five densities.
A suitable metaphor might be that of floor and ceiling. In a room objects exist between the floor and the ceiling. It is as if space/time were the ceiling and time/space were the floor (or vice versa; it could be done either way). A mind/body/spirit complex, continuing the metaphor, is like a tree with its trunk (the spirit) in the floor (time/space) and its outermost branches (the body) in the ceiling (space/time).
There are a great multitude of entities existing throughout space and time. In the most inward regions of time/space lie the spirits of sub-Logoi. In outer regions of time/space lie the unconscious minds of the sub-Logoi: individual memories, social memories, species memories, etc. There are also various time/space entities such as angels and demons which are neither sub-Logoi nor parts of sub-Logoi. In space/time lie those physical entities with which we are familiar and of which we have knowledge through the natural sciences. At the border between space/time and time/space lie those entities which interact between the two realms, such as the conscious portions of the mind complexes, time/space entities with space/time effects such as elementals, and space/time entities with time/space effects such as crystals.
I said previously that space/time is visible and time/space is invisible. This is true, but only relatively so. It would be more correct to say that time/space is invisible from space/time, and space/time is invisible from time/space. Thus the two realms are mutually blind to each other. It would be further correct to say that the conscious mind, which is a bridge between space/time and time/space, effortlessly perceives space/time accurately and completely, and is normally unable to perceive time/space accurately or completely. It does not perceive time/space at all without special stimulus. The contents of time/space can be rendered visible through numerous means. This happens for instance when a person remembers dreams, feels emotions, has mystical experiences, engages in astral projection, etc. In these events a portion of time/space is rendered visible. More precisely, there is a temporary bridge forged between space/time and time/space, and the oppositely polarized material rushing together across this bridge constitutes an event of a portion of time/space material being rendered visible and worked upon through the energy of space/time.