The notion of a "configuration space" is a way of translating object descriptions into object positions. It may seem like blue is "closer" to blue-green than to red, but how much closer? It's hard to answer that question by just staring at the colors. But it helps to know that the (proportional) color coordinates in RGB are 0:0:5, 0:3:2 and 5:0:0. It would be even clearer if plotted on a 3D graph.

In the same way, you can see a robin as a robin—brown tail, red breast, standard robin shape, maximum flying speed when unladen, its species-typical DNA and individual alleles. Or you could see a robin as a single point in a configuration space whose dimensions described everything we knew, or could know, about the robin.

A robin is bigger than a virus, and smaller than an aircraft carrier—that might be the "volume" dimension. Likewise a robin weighs more than a hydrogen atom, and less than a galaxy; that might be the "mass" dimension. Different robins will have strong correlations between "volume" and "mass", so the robin-points will be lined up in a fairly linear string, in those two dimensions—but the correlation won't be exact, so we do need two separate dimensions.

This is the benefit of viewing robins as points in space: You couldn't see the linear lineup as easily if you were just imagining the robins as cute little wing-flapping creatures.

A robin's DNA is a highly multidimensional variable, but you can still think of it as part of a robin's location in thingspace—millions of quaternary coordinates, one coordinate for each DNA base—or maybe a more sophisticated view that . The shape of the robin, and its color (surface reflectance), you can likewise think of as part of the robin's position in thingspace, even though they aren't single dimensions.

Just like the coordinate point 0:0:5 contains the same information as the actual HTML color blue, we shouldn't actually lose information when we see robins as points in space. We believe the same statement about the robin's mass whether we visualize a robin balancing the scales opposite a 0.07-kilogram weight, or a robin-point with a mass-coordinate of +70.

We can even imagine a configuration space with one or more dimensions for every distinct characteristic of an object, so that the position of an object's point in this space corr...

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