Time on space and space on time

Our culture is oriented toward space, geography, geometry, and spatial relationships. We can easily understand items on a map. Even time can be put on a map, as with an isochrone map such as the contour lines (isochrones) representing equal distances or drive times from an urban center. 3D visualizations extend this to more dimensions. One dimension of time may be projected onto two or three dimensions of space.

But the opposite is more difficult to understand: space projected onto multiple dimensions of time. For this we need a “distorted” map that shows travel times instead of (travel) distances. That is, the background is a kind of map that doesn’t show geography but rather shows temporal relationships. The foreground shows familiar spatial representations except that they may not be where they were on a spatial map. Contour lines showing equal driving distances (isodistances) on top of a temporal map provides another way to see the relationship between time (duration) and space (length).

A familiar situation in some American cities is the city grid. There is a difference between the driving distance and the distance as the crow flies, which should reflect different drive times as well. If driving times are proportional to driving distances, then equal distances from a point on the grid should approximate linearly spaced squares or diamonds. If travel times over equal distances from an urban center are shown over a map, then the drive times will be spaced further apart near the center. The opposite is the case if distances traveled in equal time periods from an urban center are shown over a map: they will be spaced closer together near the center.

A characteristic speed could be shown by equally spaced circles from a specified point on a map, with each circle representing the distance traveled in a given length of time.