If my message came across as dismissing the ki let me reiterate: I used the model as a tool, it's based on generations of experimenting and I know it works for the practical goals. My issue is that it comes with an esoteric luggage in which I don't believe, yet I'm expected to pass further on. The tool wanted to be also the goal. I assume you can't teach kung fu without some buddhism (I suppose, I'm not a kung fu practitioner) so what is the way forward? Practice krav maga? Practice by yourself on a mountaintop? Neither of those help you much advancing in what you loved... but I'm diverting already too much from the OP. My point was, community is great, but if the spiritual dimension doesn't resonate I can't remain as true member.

I can’t tell you what to do with your life.

My solution to encountering outdated beliefs with great utility was to try and update them — to retell Kung fu (and Buddhism) in that new world view. Buddhism has a maxim to keep what’s useful and discard the rest.

What does “ki” mean in physics?

I think it’s more than esoteric luggage, but a class of physics equations which are nasty to write down because they’re complex differential equations — and the numerics don’t matter to the practice, just the behavior of the system.

So you give a name to that behavior and model it experimentally, describe it euphemistically, etc.

I get spending the time to learn multiple models and translate between them isn’t everyone’s idea of fun, though. Those people reasonably make different choices than I did.

I think the question still stands: what's the point of staying in the versionthat doesn't match your core beliefs vs finding an equivalent that does?

Can you name an equivalent of Kung fu?

I can’t — so I found it necessary to dig into the old program and port the concepts.

I would argue that more people should do that, even when they don’t immediately understand the old model well enough to port.

Both in software and martial arts.