The Physics of Controlled Collisions: A Reverie About Locomotion
Imagine the following scenari o. It is late in the afternoon and since early morning you have been mulling over a long term concern of Gibson 's (1950, 1960, 1961 ,
1966, 1979), namely, the optical structure ambient to an animal that is generated by the layout of surfaces and by the animal ' s movements (both the movements of its limbs relative to its body and the movements of its body, as a unit, relative to the surface layout). You are taken by the subtlety of Gibson's point that this optical structure resembles neither the surface layout nor the movements but it is specific to them because it is nomically (lawfully) dependent on them. And you are impressed by Gibson's insistence that these dependencies between properties of the animal-environment relation and properties of the ambient light are instances of laws, indigenous to the ecological scale (the scale of animals and their environments), that make possible the control of activity .