We laid transatlantic telegraph wires before we even had a hint of the physics involved. It create the entire field of transmission and signal theory.
Shannon had to invent new physics to explain why the cables didn't work as expected.
Shannon had to invent new physics to explain why the cables didn't work as expected.
There was a lot of physics already known, importance of insulation and cross-section, signal attenuation was also known.
The future Lord Kelvin conducted experiments. The two scientific advisors had a conflict. And the "CEO" went with the cheaper option.
""" Thomson believed that Whitehouse's measurements were flawed and that underground and underwater cables were not fully comparable. Thomson believed that a larger cable was needed to mitigate the retardation problem. In mid-1857, on his own initiative, he examined samples of copper core of allegedly identical specification and found variations in resistance up to a factor of two. But cable manufacture was already underway, and Whitehouse supported use of a thinner cable, so Field went with the cheaper option. """
I guess the rise time was tens of milliseconds and rebounds in signals lasted for milliseconds or more. Hardly something you can neglect.
For reference, in my time (the 1980) in the telecom industry, we had to regenerate digital signals every 2km.
https://en.m.wikipedia.org/wiki/Transatlantic_telegraph_cabl...
I guess your bandwidth in 1980 was a bit higher.