[my comment follows Russ's] Russ Abbot writes: > As I understand it, work is defined as the change in kinetic energy > resulting from the application of a force. Normally that means work is force > times distance. So if there is no distance (no motion) there is no change in > kinetic energy and hence no work. A tug-of-war between two absolutely > balanced teams results in no work even though both sides are pulling as hard > as they can. But is that what you are really interested in? That gets us > somewhat far afield from a more general notion of constraint. Perhaps it > would be helpful if you would clarify what you care about in this context.
In what it is that Nick cares about, is there *any* reason to believe that there is *any* "conservation principle" for *anything* (in his system[s] of interest) that plays a role like that of "energy"? Only if there is such a principle, it seems to me, is there any principled way for him (or you or us or me) to distinguish some analogues of "kinetic energy" and "potential energy"; and (again, as it seems to me) without an analogue of "kinetic energy" (principled or not), the definition of "work" from physics (that you quote above) begins to drift into inanaloguizability even before we tax it by asking "what's 'force' in Nick's context?" (already under discussion), much less "what's distance/motion in Nick's context?" (only recently mooted). Lee Rudolph ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
