Oh, I'm not at all discounting the utility of it. As a statistical tool, being able to exclude either A->B or B->A based on the sign of the offset is really useful as a filter.
> However, it does informally bring the results closer to causation. So I won't call it "causation" per se. Just call it something similar "granger causation."
I think this is the main point where my confusion comes from. Calling it "Granger causation" makes it sound like a special case of causation, causation with a stronger condition tacked on. For something stronger than generic correlation but weaker than causation, it seems like "Granger correlation" would be a better term.
> Experimental physics isn't asking causative questions. It's more asking how well does the data fit a particular model. It's purely correlative, there's no drive to answer anything causative here because it doesn't make sense.
I don't think this is accurate. When asking how well data fits a model, typically the model asserts some causation. For a model predicting "If A, then B", an experiment would set up condition A, and observe whether B also occurs. The role of experimental design is to produce an environment in nothing else could cause B, such that a correlation could only be produced from causation.
(Granted, from an epistemological viewpoint, Descartes could still doubt such a case and call it purely correlative, but that veers from physics to philosophy.)
> When experimental data closely correlates with say Newtons law of motion does it make sense to say Newtons laws caused the data to come out that way?
No, but it would make sense to say that Newton's Laws states that a causal relationship exists. For the statement "An object at rest will stay at rest, unless acted upon by an outside force.", in an environment with no outside force, the model predicts that the effect of "an object stays at rest" is caused by the initial condition of "an object is at rest".
>The role of experimental design is to produce an environment in nothing else could cause B, such that a correlation could only be produced from causation.
Causation is not established from isolated correlation. If I completely isolate two atomic clocks but I start off those atomic clocks at the same time it does not mean one atomic clock, causes the ticking of the other even though their ticks are in sync or they have "granger causation" and can have no other form of influence.
Causation is only established by having the experimenters hand within the experiment itself. If A causes B then I have to turn A on and turn A off randomly and see if B responds as predicted. That is how causation is established. Isolation helps with this but the critical factor here is that experimental intervention is the thing that establishes causation. Remember: Correlation is an observation, causation is an intervention, then subsequent observation to see how the system reacted to the intervention.
Physics experiments focus more on the observational side of things. The causation is more meta. You're not asking if A causes B, more your asking if the concept of "A causing B" even exists.
>No, but it would make sense to say that Newton's Laws states that a causal relationship exists
This doesn't make sense. Newtons laws or physics in general define what causality means. Right? It defines the rules for how one particle "influences" another particle... hence it defines the nature of causality itself.
Do you see the difference here? You're not investigating whether or not A causes B. You're investigating the definition of "causes." Hence it's a observational experiment. It's a much more meta... and as a result becomes purely correlative as we can only observe physics, we can't change or intervene within the experiment itself to change physics.
> However, it does informally bring the results closer to causation. So I won't call it "causation" per se. Just call it something similar "granger causation."
I think this is the main point where my confusion comes from. Calling it "Granger causation" makes it sound like a special case of causation, causation with a stronger condition tacked on. For something stronger than generic correlation but weaker than causation, it seems like "Granger correlation" would be a better term.
> Experimental physics isn't asking causative questions. It's more asking how well does the data fit a particular model. It's purely correlative, there's no drive to answer anything causative here because it doesn't make sense.
I don't think this is accurate. When asking how well data fits a model, typically the model asserts some causation. For a model predicting "If A, then B", an experiment would set up condition A, and observe whether B also occurs. The role of experimental design is to produce an environment in nothing else could cause B, such that a correlation could only be produced from causation.
(Granted, from an epistemological viewpoint, Descartes could still doubt such a case and call it purely correlative, but that veers from physics to philosophy.)
> When experimental data closely correlates with say Newtons law of motion does it make sense to say Newtons laws caused the data to come out that way?
No, but it would make sense to say that Newton's Laws states that a causal relationship exists. For the statement "An object at rest will stay at rest, unless acted upon by an outside force.", in an environment with no outside force, the model predicts that the effect of "an object stays at rest" is caused by the initial condition of "an object is at rest".