On getting his feet back under him when asked in a clinic I was in, Jeb replied, "I just huck my junk forward. "
Mike, I like what you say,
"Back to Egan's point -- we are always adjusting to the changing forces that we experience in skiing -- it's not like it is a stable system were change is predictable and continuous. Groomer skiing might be the most predictable and closer to continuous, but even so you may encounter differences in slope, terrain, or snow quality to result in non-monotonic if not discountinous change, and that requires significant adaptation to stay over the ski (e.g. recovery). So, what differentiates equilibrium from balance from disequilibrium and out of balance? Falling vs. recovery?"
There is always continuous change and adaptation to stay over the skis. Skiing is always a dynamic system with often competing forces to which we must adapt and change to stay in balance or recover it. I think equilibrium describes when all the forces within the system are in balance as it is used by Jeb and others. And it is the descriptor within the article that is most speaking to the 4 principles described, as a dynamic system. I don't think there is any disagreement between what several are trying to say above and what Jeb is talking about. I also believe that what they are trying fo focus on are the most precise ways to stay in balance within the dynamics of skiing.
I think Jeb and others are trying to be very exact with the use of language in a effort to make instruction clearer and simpler and more consistent across PSIA. Doing that successfully is for the benefit of the instructors (particularly new instructors still developing their understanding of what is going on, along with a broad conceptual framework to house all the concepts). The better understanding the instructor has of what he is trying to teach, the more effective he will be as a teacher. Being able to communicate clearly and simply brings consistent and greater success to students.
"Returning to Boyd, I think of equilibrium as a state in which al forces are in balance within the system, meaning there will be noticeable change to the system without some introduction of a force external to the system. Presumably some equate balance with equilibrium. But I personally don't see how either concept in those definitions describes the reactions we have to take to deal with the chaos experienced in skiing. "
I absolutely agree with your description of equilibrium in the first sentence, but I also think that balance as we think of it fits well into that model - the result is that we are in balance over our skis when all the forces within our system are balanced appropriately.
The difficulty with language as applied to describing skiing is that we often have to take "snapshots" of particular moments to sensibly describe what is going on to our students or each other. The limitation of language is that it seems to treat the described moment as if what is going on is static, which ALL OF US know is not the case. Nevertheless, that is where we start.
Whether or not Jeb's (and PSIA's) way of presenting it is more effective than our present structure is yet to be determined. Some here are making the point that this is not successful way to do it. But let's keep the discussion going, for the edification of all participants and readers.