The few "top-down" examples where theory preceded application (like nuclear energy or certain modern pharmaceuticals) are relatively recent historical anomalies.
Fun fact: we have no clue how most drugs works. Or, more precisely, we know a few aspects, but are only scratching the surface. We're even still discovering news things about Aspirin, one of the oldest drugs: https://www.nature.com/articles/s41586-025-08626-7
We only understood in the broadest sense. It took a long process of iteration before we could create steam engines that were efficient enough to start an Industrial Revolution. At the beginning they were so inefficient that they could only pump water from the same coal mine they got their fuel from, and subject to frequent boiler explosions besides.
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.
It’s complicated but they are most definitely created.
For steam engines, the first commercial ones came after and were based on scientific advancements that made them possible. One built in 1679 was made by an associate of Boyle, who discovered Boyle's law. These early steam engines co-evolved with thermodynamics. The engines improved and hit a barrier, at which point Carnot did his famous work.
This is putting aside steam engines that are mostly curiosities like ones built in the ancient world.
See, for example
Otherwise we'd all be writing Haskell now. Or rather we'd not be writing anything since a real compiler would still have been to hacky and not theoretically correct.
I'm writing this with both a deep admiration as well as practical repulsion of C.S. theory.