What does "well understood" mean exactly? Ask the average inhabitant of Hacker News and he will tell you that "Faraday Cage the name of a phenomenon whereby a box of metal prevents electromagnetic fields inside", or something like that. But ask him how the strength of the electromagnetic field depends on the wire radius and mesh size, and he might not know the answer.
That said, the answer was known to Maxwell, as the author remarks, although not to the author himself. As is often the case, the problem is in the details. So in a sense, it is a well understood problem to people who know the details well enough.
I'm a physics graduate I did not know the answer, and I can assure you that the average physics graduate doesn't know the answer. In the year 2000 a graduate course in physics contains so much "advanced" physics that you end up learning a bit of a lot instead of a lot of a bit. My contemporaries and I know a lot of physics superficially, unfortunately. Time is limited, and in university you learn what you're fed.
But yes, I agree with the sentiment of your post, of course :-)
A second-year Physics student can work out RF shielding using Kirchhoff's diffraction formula, or just looking at the wave equation in the k domain (spatial frequencies). Electrostatic shielding is the hard bit addressed in the article.
I'm not sure the diffraction formula has much relevance for computing shielding. I thought that formula was an idealization where you assume that the field strength on the blocking parts is identically zero, but I don't think that's a good approximation if you have a small mesh. Even if there's no propagating wave, there'll still be an evanescent wave going past the mesh, and you don't know how high that field will be.
That said, the answer was known to Maxwell, as the author remarks, although not to the author himself. As is often the case, the problem is in the details. So in a sense, it is a well understood problem to people who know the details well enough.
I'm a physics graduate I did not know the answer, and I can assure you that the average physics graduate doesn't know the answer. In the year 2000 a graduate course in physics contains so much "advanced" physics that you end up learning a bit of a lot instead of a lot of a bit. My contemporaries and I know a lot of physics superficially, unfortunately. Time is limited, and in university you learn what you're fed.
But yes, I agree with the sentiment of your post, of course :-)