>Tangentially, if anybody could explain why "Granger causality" is named "causality", I'd appreciate it. From the descriptions I've found, it does not in any way require a causal relationship, and naming it as a type of "causality" would only serve to conflate correlation and causation. I cannot fathom of any reason why it should be named "causation", without assuming intent to confuse.

I'm not a scientist, but I think I know why. Think in terms of the field epidemiology. That field is largely observational. All experiments can formally only come to correlational conclusions but the intent and end goal of the field in spirit is to come to a causative conclusion.

Take for example say if I wanted to answer the question if Sexual intercourse causes people to be infected with HIV. I can't do a causative experiment here as that would involve a double blind test of actually infecting sample groups with HIV via sex. As an epidemiologist my only tools available are correlative experiments where I observe things in the real world.

You see the disconnect here right? Correlative answers are useless, we want to know what "causes" HIV, but the only thing I have as a scientist are correlative experiments. How would I come to a causative conclusion? The answer is I can't. Formally I can only establish correlations then comment about the correlations qualitatively and explain why I think there's an underlying causation underneath.

Well let's say in my experimentation (the observational one) I observe that people were randomly getting HIV before sexual intercourse and after sexual intercourse. That eliminates causality all together because we know that cause MUST come before effect.

However let's say in my experimentation everyone who got HIV, consistently got it AFTER they had sex. That does not eliminate causation... but it doesn't establish it either. 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." Hence the term. That should answer your question.

Again I'm not a scientist, but I can only guess as to why a physicist never encountered these terms. I think it's because you guys only do a special type of correlative experiment where you correlate whether certain observational Data fits a mathematical model. 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.

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? Not really, it sounds off. Also how would you do a double blind test here?

Ultimately causative experiments involve the experimenter inserting himself into the experiment and using himself as the source of causation in order to establish causation itself. In medicine they do this by deliberately giving medicine to a group of people to see the effect and not giving it to another group of people to also see the negative effect in the data. It seems that if you were to do this with physics it would involve you removing the laws of physics from the universe then putting it back to see how it effects the experimental data... not possible and also doesn't fully align with the goal of physics experiments.