I think the confusing part is that the rule is presented without the problem it solves.
The problem is when you take two vectors in 3d and want to find the vector orthogonal (perpendicular) to both, you have 2 valid choices.
The right hand rule is a way to pick the same one every time if you always label the two vectors you start with consistently i.e. make your thumb vector 1, pointer vector 2, then your middle finger points the direction of a perpendicular vector that matches the handedness of the hand you used.
This matters anywhere a vector cross product is used in physics, like calculating what direction an electron feels force when moving through a magnetic field. The physics doesn't change, but you'll have negatives in different places when comparing results calculated with a right handed convention (coordinate system) with a left handed convention.
When checking the handedness of your coordinate system, you point your thumb and pointer finger in the positive direction of any two dimensions then check if your middle finger points in the positive direction of the third dimension.
I've been using a pi3 b+ with octopi and so far it's great even without obico, plus super easy to set up. I set up octopi to get my ender 3 away from high occupancy areas because the hot plastic VOCs were giving me paranoia :P
I can recommend investing in a solid setup for any small computer used to drive 3d prints. My setup is a hack with no thermal management and a crap power supply and I've lost a couple of prints to unknown causes but I blame the raspberry pi (it's almost always reporting under voltage events in the octoprint UI).
Has anyone here run self-hosted obico? I'm not keen on the cloud version but if the failure detection works in self hosted mode I'm definitely going to give it a try.
The nyquist shannon sampling theorem is the idea that as long as you capture 'samples' of signal (like the air pressure over time that is sound) faster that twice the period of the highest frequency component of the signal, all the information is captured and the aignal can be reproduced exactly (in theory).
maybe think of it like looking through a fence. As long as nothing on the other side of the fence is shorter than the spacing between posts, you can everything on the other side.
note that any file can be encoded as text with something like Base64
Why not... Three linear polarizers?
Then you can really do some field reorientation
... Come to think of it, why not four or five?