Question

Why does the universe appear to have one time and three space dimensions?

Answer 1

The universe has 3 dimensions as we feel, see visually and experience it. The three mutually perpendicular dimensions seem to describe the space.

Now at each point (x,y,z) we see visually that value of it changes (evolves) over time. Hence, we have another dimension to Universe as time t.

Any other quantity we could think of a dimension to the Universe seems to fit into the above four dimensions. So Universe has those dimensions.