The addition of a second spatial dimension raises the possibility of showing local perturbations of the spatial geometry by local curvature in the sheet.

The table gives results for wave propagation in one horizontal spatial dimension.

Or the concept of a fourth spatial dimension.

The protagonist describes the passing of time, and also treats it as if it were a spatial dimension.

A simplified form of the equation describes acoustic waves in only one spatial dimension, while a more general form describes waves in three dimensions.