https://astro.uchicago.edu/~frisch/2015 ... lament.pdf
I’m hoping everyone sees the significance of this, as we couldn’t have asked for a better set of observations, and sortation of that data. (Also, a reminder that you really have to read Priscilla Frisch, if you want to understand the layout of Birkeland currents on the local interstellar scale.)
Read the very last paragraph first (“note added in proof”), and ask yourself what they are seeing.
They first found a seeming correlation between polarization angle with distance (Don Scott’s model should be screaming at you already), but then they disregard it as “spurious”, because it seemed to depend on the choice of stars (local or more distant), and coordinate system of choice.
Now, put this article in the back of your head for a minute, and ask yourself what we should see, if Don’s model is the correct way to model current filaments, but we have small scale local filaments, all inside larger scale Birkeland current filaments. I bet you’ll make the same prediction, that they in fact observed.
Let’s try it from the top: if Don Scott is right, when we look out radially from inside one of his filaments, we should see a rotating magnetic field direction. This is most apparent when we look out radially in that filament, and the effect disappears completely when we look down the filament axis. We should observe this effect when looking at local stars. But what if we are also in a larger scale filament? We should also see this rotation of magnetic field when looking out radially from this filament too. Only the rotation of magnetic field with distance will be dependent on the direction of this filament (and the coordinate system that best matches it). And it will be best mapped with a larger scale distribution of stars.