. Design for a brain. Brain -- Physiology; Central nervous system -- Mathematical models; Neurophysiology. STABILITY 4/5 4/4. This preliminary remark begins to justify the emphasis placed on absoluteness. Since stability is a feature of a field, and since only regular systems have unchanging fields (S. 19/16) it follows that to discuss stability in a system we must suppose that the system is regular : we cannot test the stability of a thermostat if some arbitrary interference continually upsets it. But regularity in the system is not sufficient. If a field had lines criss-crossing like those o
. Design for a brain. Brain -- Physiology; Central nervous system -- Mathematical models; Neurophysiology. STABILITY 4/5 4/4. This preliminary remark begins to justify the emphasis placed on absoluteness. Since stability is a feature of a field, and since only regular systems have unchanging fields (S. 19/16) it follows that to discuss stability in a system we must suppose that the system is regular : we cannot test the stability of a thermostat if some arbitrary interference continually upsets it. But regularity in the system is not sufficient. If a field had lines criss-crossing like those of Figure 2/15/2 we could not make any simple statement about them. Only when the lines have a smooth flow like those of Figures 4/5/1, 4/5/2 or 4/10/1 can a simple statement be made about them. And this property implies (S. 19/12) that the system must be absolute. 4/5. To illustrate that the concept of stability belongs to a field, let us examine the fields of the previous examples. The cube resting on one face yields an absolute system which has two variables : (cc) the angle which the face makes with the horizontal, and (y) the rate at which this angle changes. (This system allows for the momentum of the cube.) If the cube does not bounce when the face meets the table, the field is similar. O O o a o o o Figure 4/5/1 : Field of the two-variable system described in the text. Below is shown the cube as it would appear in elevation when its main face, shown by a heavier line, is tilted through the angle x. 45. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ashby, William Ross. New York : Wiley
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Keywords: ., bookcentury1900, bookpublishernewyorkwiley, booksubjectneurophys
