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