= 27d567bc2d48d9f40e9ccc20ea370b15)
gjm comments on What is control theory, and why do you need to know about it? - Less Wrong
You are viewing a comment permalink. View the original post to see all comments and the full post content.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
Powered by Reddit
= f037147d6e6c911a85753b9abdedda8d)
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (47)
Er, I think you mean Navier-Stokes.
I think that's unfair. The notion of an implicit model (meaning something like "a model such that a system making use of it would behave just like this one") is a useful one; for instance, suppose you are presented with a system designed by someone else that isn't working as it should; one way to diagnose its troubles is to work out what assumptions about the world are implicit in its design (they might not amount to anything quite so grand as a "model", I suppose) and how they fail to match reality, and then -- with the help of one's own better model of the world -- to adjust the system's behaviour.
Or, of course, you can just poke at it until it behaves better. But then I'd be inclined to say that you're still using a model of the world -- you're exploiting the world's ability to be used as a model of itself. If a system gets "poked at until it behaves better" often enough and in varied enough ways, it can end up with a whole lot of information about the world built into it. If you don't want to call that an "implicit model", fair enough; but what's wrong with doing so?
Poking at it until it works isn't revising a model, in the same sense that walking toward the pole star when you want to go North isn't cartography.
I didn't say that poking at something until it works is revising a model, I said that it's using a model (in, doubtless, a rather trivial sense). And, if I'm understanding your analogy right, surely the analogous claim would be that walking (as nearly as possible given that one remains on the surface of the earth) towards the pole star isn't reading a map (even an "implicit" one), not that it isn't cartography; and I don't think that's quite so obvious. (Also: it seems to me that "maps" have more in common than "models", and I think that's relevant.)