Dear anybody,
I am reviewing a book by a psychologist in which the author makes a distinction between constraints and causes. Now perhaps I am over thinking this, but this distinction seems to parallel one made by Feynman in his famous physics text, where he defines a constraint as a force that does no work. If I have it right, the idea goes like this: If you place a bowling ball on a table the ball neither receives work from gravity nor does the table do any work holding the ball up because the ball does not move, and work is just the movement of mass. Indeed, even if you were to slide the table out and, with great effort, were to hold the ball in the same position for an hour, you wouldn’t be doing any work, either. Similarly, in a ball rolling down an inclined plane, the plane itself does no work because even tho it affects the motion of the ball, its effect is always perpendicular to the motion of the ball and there fore affects its motion neither one way or the either …. i.e., does no work!
Now I would leave it at that except that Alicia Juarrero in her book also makes a huge distinction between forces and constraints, one which I think our own Steve Guerin applauds. It is the constraints that make it possible for far-from-equilibrium systems to self organize and do work. Perhaps I can make this work with Feynman’s definition if I think about the dam beside a water wheel, and the water wheel itself, as applying constraints to the water (they do no work themselves) which make it possible for the falling water to do work. Am I still on track, here?
Now Juarrero goes on to make a distinction between between context sensitive and context-free. I have read these passages dozens of times and I just don’t understand this distinction. Can anybody out there explain it to me as to a Very Small Child.
Thanks,
Nick
Nicholas S. Thompson
Emeritus Professor of Psychology and Biology
Clark University
http://home.earthlink.net/~nickthompson/naturaldesigns/
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