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Can you represent the whole theory in the model? The model would need to represent evidence that its representations of the world are accurate. If that eviden

by lg 16y ago

Can you represent the whole theory in the model? The model would need to represent evidence that its representations of the world are accurate. If that evidence is a mathematical proof, a program could probably encode it. But if it's experimental evidence, I don't know how it could.

barrkel 16y ago
That seems backwards to me. Theories don't "represent" evidence, experimental or otherwise (I'm not even sure what that's supposed to mean, it doesn't make sense to me). You formulate your theory - which is a model of cause and effect - from one set of observations, and test it with another set of observations. The model - the theory - may include facts from experimental evidence, eg G the gravitational constant, but that doesn't seem problematic for theory representation in program form. Theories make predictions about the world. I'd argue they're useless without this. As such, they are function of a prior state, returning the new state. Certainly you can't validate your theory without doing physical experiments, or at least having lots of data that the theory was not based on, to check it. But validation of a theory is distinct from its representation.
- whimsy 16y ago
  "Theories should pay rent in anticipated experimental data."
- lg 16y ago
  say i have a theory that says, changes in temperature depend on changes in pressure in some specified way. And you say, oh I have a similar theory, it's a computational model. In my model of the universe, when my model of temperature changes, then so does my model of pressure, and it changes in exactly the same way your theory describes. I'd say ok, that's a great theory about your model of pressure and your model of temperature in your model of the universe. And you say, no no, this is a theory about actual pressure and temperature in the actual universe, just like your theory. In that case your model is not enough. I also need reason to believe that your models of temperature and pressure are relevantly similar to actual temperature and pressure such that relational properties that hold of the entities of your model also hold of the entities they're supposed to represent. If it turns out you modeled temperature as a jpeg representing a picture of a cat, then how is that a theory about the temperature? Whereas my theory is a theory about temperature simply because my theory says: temperature, that real thing in the world, will do such-and-such.
  - barrkel 16y ago
    Both the theory and the model depend on the definitions of their constituents. If you don't have a theory of temperature or pressure, your theory is similarly useless, because you will have no way to interpret the words "temperature" and "pressure". Your theory assumes these things, but you want to say that the model is invalid because it also assumes these things. But the more important misconception you appear to have is that you are not considering the human element; no representation of the theory has meaning unless a human interprets it. Programs manipulate symbols; but it is the human who chooses what the symbols mean, and that includes incorporating theories / models implied or assumed about those meanings. It's no different for a theory written down in a book.

by lg 16y ago

barrkel 16y ago

That seems backwards to me. Theories don't "represent" evidence, experimental or otherwise (I'm not even sure what that's supposed to mean, it doesn't make sense to me). You formulate your theory - which is a model of cause and effect - from one set of observations, and test it with another set of observations. The model - the theory - may include facts from experimental evidence, eg G the gravitational constant, but that doesn't seem problematic for theory representation in program form. Theories make predictions about the world. I'd argue they're useless without this. As such, they are function of a prior state, returning the new state. Certainly you can't validate your theory without doing physical experiments, or at least having lots of data that the theory was not based on, to check it. But validation of a theory is distinct from its representation.

whimsy 16y ago
"Theories should pay rent in anticipated experimental data."
lg 16y ago
say i have a theory that says, changes in temperature depend on changes in pressure in some specified way. And you say, oh I have a similar theory, it's a computational model. In my model of the universe, when my model of temperature changes, then so does my model of pressure, and it changes in exactly the same way your theory describes. I'd say ok, that's a great theory about your model of pressure and your model of temperature in your model of the universe. And you say, no no, this is a theory about actual pressure and temperature in the actual universe, just like your theory. In that case your model is not enough. I also need reason to believe that your models of temperature and pressure are relevantly similar to actual temperature and pressure such that relational properties that hold of the entities of your model also hold of the entities they're supposed to represent. If it turns out you modeled temperature as a jpeg representing a picture of a cat, then how is that a theory about the temperature? Whereas my theory is a theory about temperature simply because my theory says: temperature, that real thing in the world, will do such-and-such.
- barrkel 16y ago
  Both the theory and the model depend on the definitions of their constituents. If you don't have a theory of temperature or pressure, your theory is similarly useless, because you will have no way to interpret the words "temperature" and "pressure". Your theory assumes these things, but you want to say that the model is invalid because it also assumes these things. But the more important misconception you appear to have is that you are not considering the human element; no representation of the theory has meaning unless a human interprets it. Programs manipulate symbols; but it is the human who chooses what the symbols mean, and that includes incorporating theories / models implied or assumed about those meanings. It's no different for a theory written down in a book.