Earlier quoted context omitted.
You are ktizo both have the same misconception. Perhaps this explains your belief in the value of models. Those formulas are not models! They are exact mathematical representations of a phenomena! A model by it's nature can not include everything, they include everything possible of course, but the world is too complex for them to include everything, so they must estimate. If you have a feedback loop with the real wo…
Those formulas are models. They describe the world and can predict it's behaviour, but can also break down under certain conditions. For example, what happens when I put 240V across a regular 20Ohm resistor? According to V=IR you get 12A running through it - but I doubt you'll get that for very long. By your argument, V=IR must then be a "model" and is useless, with no predictive power, etc, etc. In practice, the onl…
You think V=IR describes a resistor, it does not. It describes electricity. So it's not surprising that when applied to a resistor it doesn't work. You are trying to model a resistor, but you are not including everything in your model, so it fails.
Which is exactly what I'm warning about.
> By your argument, V=IR must then be a "model" and is useless, with no predictive power
V=IR is not a model. Using it to describe a physical resistor is a model.
Suppose I never touched a real resistor in my life, and the only information I had was an understanding based on some other law that V=IR. Now I want to use that information to predict what a resistor will do. I will fail - among other things it doesn't take into account inductance or capacitance.
Which is why it is very very important to know what your equation describes. You thought that V=IR completely describes a physical resistor, when it does not.
Now you know why it's incredibly dangerous to try to learn anything from a model. If even something as simple as Ohm's law can be confusing, imagine how many error a model with hundreds of equations has.