Comment by bsder

> I don't get why EE education emphasizes problems of this sort

Last I checked, they don't. I certainly never hit an "infinite grid of resistors" in general circuits and systems except as some weird "bonus" problem in the textbook.

Occasionally, I would hit something like this when we would be talking about "transmission lines" to make life easier, not harder. ("Why can we approximate an infinite grid of inductors and capacitors to look like a resistor?")

It's possible that infinite grid/infinite cube might have some pedagogical context when talking about fields and antennas, but I don't remember any.