niconiconi
The history of electromagnetism is truly bizarre when you think about it. The theory was essentially 100% complete in 1873 in A Treatise on Electricity and Magnetism. Well, supposedly complete - as nobody could really understand its content fully, not even the author. Maxwell introduced the displacement current as a small technical fix, but failed to realize it could generate E&M waves. The reanalysis of the book took physicists 10 to 20 years. Pupin traveled from US to Cambridge because he wanted to ask the question "WTF is the book?" personally to Maxwell. The young Heaviside said understanding this book was his life goal (realized during 1880-1890). During this period, nobody really knew for sure that E&M waves exist. Even after Hertz demostrated E&M waves, physicists all believed it was a short-range effect like light. Then in 1895 Marconi discovered a practical longwave ratio transmitter by random tinkering. After he heard telegraph transmitters are grounded, he tried it too, accidentally inventing the monopole antenna by sheer luck (and also made it the first case of "cargo cult grounding" in RF electronics, today still practiced by many technicians that should know better). Except that it actually worked for him spectacularly because of a quirk of the Earth's atmosphere. Physicists had absolutely no idea about it and the explanation at that time by physics guru Sommerfeld (the Zenneck surface wave solution to Maxwell's equation) was completely wrong. In 1905, there was already special relativity but still little understanding about antennas and waveguides in general. Some people actually argued that special relativity made E&M simpler... #electronics
Feb 20, 2024 at 11:05pmWeb
Show threadmdnFeb 21, 2024
@niconiconi
>The history of electromagnetism is truly bizarre when you think about it.
The history of any knowledge is bizarre, if you look at math for example without Fourier/cooley/tukey works we wouldn't have sound, the internet etc...
Loads of theoretical mathematics from XXX years ago keeps either getting validated or not to this day. And will probably continue as such.
Show threadDavid PFeb 21, 2024

@niconiconi

Yeah, as I understand it, Einstein cited Maxwell's equations as an inspiration for Special Relativity.

Show threadniconiconiFeb 21, 2024
@pewnack One can say that the entirety of special relativity is designed around Maxwell's equations, it's a way to keep Maxwell's equations consistent under different reference frames. It's why I said "some people actually argued that special relativity made E&M simpler..." There are quite a few problems and paradoxes in classical E&M that are hard to explain but become more natural if you invoke relativity (even in low-speed cases).
Show threadkeithzgFeb 22, 2024
@niconiconi @pewnack It bugged the hell out of me that even in first-year university Physics my education STILL didn't use Relativity other than to sometimes reference it existing, because so much else of physics that we were being taught is actually really unintuitive and complicated sans Relativity! Relatedly, fuuuuuuck Newton
Show threadThree plus or minus fiveFeb 21, 2024
@niconiconi Wait, light is a short-range effect? I know some astronomers who are going to be very confused…
Show threadniconiconiFeb 23, 2024
@ThreeSigma Well, if your radio transmitter powered by the equivalent of a Dyson sphere you can always brute-force it...