Taking a sledge hammer to pound an "unknown" to fit into some terminology or a model that is "known" to you, absolutely will not result in anything accurate or helpful to your understanding of what IP/IS is. It's kinda like saying that an elephant is a big, nekkid horse with a stretched out nose, because you know what a horse is and don't want to consider that an elephant might be something else.
When the human body/mind and its complex neuromuscular physiological activities are involved, it's not so cut and dried as basic physics (or whatever it is you're referring to), any more than saying that IP/IS is a product of the force of gravity. That model is not directly relevant. Terminology here serves only to obfuscate meaning when we're all using the same words to describe different things.
I don't know whether anyone is playing with the scientific lexicon to explain IP, and I'm pretty sure that it's not necessary for learning how to do, as generations of internal-power adepts have somehow muddled by without it, but the process certainly can be described in very specific physical, instructive terms. The point here is not that no one can explain it, but that no one cares to do so on a public Internet board, for reasons that are pretty obvious... to some folks, at least.
If something exists, it can be explained by physics. And sure, I do not need to understand how an internal combustion engine works in order to own a car, but the engineering degree sure makes driving the car a more controlled and enjoyable experience, makes fixing or modifying the car MUCH MUCH easier, and makes educating someone else on how to operate, repair, maintain and customize their car much easier.
Complex neuromuscular physiology is basic physics, from the ion pumps that transmit nerve impulses to the force vectors inherent in a muscle contracting in order to move a bone or two. This IP stuff is SCREAMING for an ambitious bioengineering grad student at a liberal and well funded college, or a couple NSF grants. Hmmmmmm. IP or sustainable energy engineering? Hmmmmm.
I doubt anyone would consent to performing their stuff stuck full of EMG leads. Suckers hurt.....