I think the question of whether field lines are real is more of a philosophical (of physics) question so it usually falls outside the scope of introductory material on E&M. However, some texts like Purcell and Morin do kinda take a stance on whether fields are real: "since it works, it doesn’t make any difference."
Very much this. The (standard model's) "answer" is that the four vector potential probably is the "most real" and we're all just excitons along for the ride.
At some point the definitions become almost circular and opinions about what it fundamental have shifted a bit over the centuries. The cgs system of units -- which differs profoundly from SI in the treatment of electromagnetism -- was associated with those who viewed D and H rather than E and B the most fundamental. I'm quite happy with the level of theory used being appropriate to solve the problem at hand. There's always a bit of wiggle room around exactly what that problem is, however ;-)
So, a bit like how the conventional depiction of electric flow is in the opposite direction of the actual electron travel?
It doesn't matter in terms of the math (in the vast majority of situations), so while the conventional idea of electric flow is incorrect, we keep it anyway.
I think it is closer to the conventional view of current as the travel of electrons down a wire.
Current moves far faster than electrons. it is more similar to a wave in the ocean with the electrons being the water molecule.
As a result, and counterintuitively for most, the speed of electrons will give you a completely wrong answer for when a light will turn on after you flip a switch.
Current is the movement of charges. It cannot “move” faster than said charges. (Or, perhaps, you meant the electomotive force that makes the electrons move along the wire, then sure, that thing spreads pretty quickly.)
yes, the EM force, Field, or whatever it is called. I still struggle, mostly because I was taught a fundamentally flawed model for how electrical power is transmitted.
Current is about the throughput of electrical charge at a specific point of an electrical circuit, while what you're describing seems to be about the latency or the speed of electricity.
am i the only one for which programming language textbooks, papers, blog posts, etc. in racket are really hard to follow? the fact that the languages that is being operated on often looks exactly like racket makes it really hard to separate the two if i wanted to follow the tutorials in any other language.
CEK[1] machines are very clean way of implementing continuations or other features that can be implemented in terms of them in a language with no support for lambdas or closures. they are also reasonably fast too. i implemented a simple unlambda[2] interpreter in haskell using the cek/cesk style and it was ~20% faster and more memory efficient than the fastest c interpreter i could find.
