Categorical Mental Imagery: Visualizing the 4th Spatial Dimension

We present a colorful and novel discussion of mathematical techniques of visualizing a fourth spatial dimension. We first discuss notions of dimensionality including the homotopy dimension for objects in an (infinity,1)-topos. We try to visualize the fourth spatial dimension using color, and illustrate this with four-dimensional ice-cream. We apply categorical negative thinking to what we have called (infinity,1)-visual epistemology. The aim is that visualizations of higher spatial dimensions can occur functorially. We illustrate with five images five conjectural methods for how to visualize the fourth spatial dimension.