ABSTRACT
What kind of physical system is a terrestrial animal in the act of locomoting? A rationale will be provided in this chapter and the next for the claim that, in locomoting, a terrestrial animal assumes a pendular, clocking mode of organization. This mode of organization will become the topic of experimental study. The main experiment is described in Chapter 6, and its results and those of other related experiments are pursued in the chapters that follow. Of particular concern to the present chapter is the clocking aspect—the energy-flow process by which the organization that typifies locomotion can be sustained. The popular interpretation of the flow of energy that supports a biological rhythm as analogous to the escapement of a standard, man-made timepiece is rejected. This rejection is based on physical considerations that comprise the larger part of this chapter. In place of the clock escapement, an escapement is proposed that arises naturally when energy courses through structures with available macroscopic degrees of freedom whose energy-absorbing capacity is limited, whose persistence is independent of the coursing energy, and whose transition states are not associated with shock waves.
