Geometrically, the chances that an equivalent configuration would occur by random is therefore only in a 100 million and that is for a very simple, barren case. For a room without the size restriction or with furniture and structured surfaces, the chances are many orders of magnitude smaller yet.
Physical constraints. Solid chunks of matter can not be distributed arbitrarily in space, especially not in a gravitational field. Hence, out of the total set of geometrically possible configurations, only a subset can be physically realized (Todd, 1985). The subset that can be realized through more or less natural shaping processes is even smaller. The physical constraints that apply to the manufacture of roomlike enclosures include gravity and other load forces, strength and weight of materials, methods for shaping and joining parts, economy of space, materials, and labor. One must then ask, do prevailing physical and ecological constraints suffice to exclude the kind of room shapes that would be projectively equivalent with normal rooms? (Runeson, 1988, p. 299).Part of why I like this is that it seems to me to be talking about the good old-fashion geometry and physics I learned in college and before. I get that.
But, it also makes me wonder how one fits the talk of affordances and the ecologically meaningful into the story. Affordances and ecological meaning here seems to me to be superfluous. So, I don't really see how Runeson needs the kind of thing that Gary describes in comments on this earlier post:
I think the best way to get a grip on ecological information is to forget about the complexities of higher mammalian perception and look at the bacterium as the exemplar of detecting ecological information.
If you put a bacterium in a sucrose solution, the bacterium is able to detect or discriminate the differential sucrose gradients and orient itself such that its propulsion will maximize the exposure to sucrose. For ecological psychology, *this* is the paradigm case of successful perception. The ecological information in this example is the nutritional properties of the sucrose. There is nothing intrinsic to the sucrose molecule that makes it "ecological information" or "nutrition". Rather, it is ecological information only in relation to the nature of the bacterium's specific metabolism. But this doesn't make it "subjective".