We can talk about "ki" in almost mystical terms or we can talk about ki as in physical energy (or actually quite a few other things as well). The latter is vastly more amenable to a physics based discussion than the former, for instance.

Now me, personally, I do not agree with Erick's analyses. Not at all. I've been on the mat with a lot of very good people, felt it in person, and being of a scientific background myself very little of what Erick writes, with all due respect, rings true for my direct experiences of it and subsequent training of it, whatever that "it" is. *That said*, I fully respect his attempt. I fully respect his approach. I think it he got out on the mat with some of the so-called "big dogs" and tried some of what he's saying he might change his course a bit. But... I have zero problem with him trying to formulate his theories and approach. And it's not to say that much of what he's talking about isn't good and interesting either. I just don't think it cuts to the heart of what's really going on, at least in my experience, my training, and my background as well. But more power to him.