Space is inferred by relationship of things.
More precisely, time can be known only by the change in the physical relationship of things.
The processes of sensation, perception, and knowledge-building are not understood at first. We only gradually become aware of them.
To be aware of one as a self requires cumulative experience. It is a kind of revelation.
First knowledge of reality is the sense of matter. How it is known is not reflexively known to the sensor until the awareness of self as thing.
The change in the physical relationship of things in space is time and the measure of time.
The world consists of things and space.