No argument here! Great points.
Yes they are. “The terms light, electromagnetic waves, and radiation all refer to the same physical phenomenon: electromagnetic energy.”
https://science.nasa.gov/ems/02_anatomy
Light and radio are both electromagnetic energy. Radio waves and light both propagate at the speed of light. The speed of light in a vacuum is a universal constant. The speed of light in various mediums is always slower. Among copper, air and glass, light/EM waves will propagate the slowest in glass and the fastest in air.
https://en.wikipedia.org/wiki/Speed_of_light
> cannot make use of light through air even a fraction as efficiently as light through fiber optic cable, due to a guaranteed minimum amount of light interference in air that a fiber optic cable will never have, right?
No, not right. As someone else pointed out a point to point link through the air will have lower latency than fiber (glass or plastic).
Whether or not a signal can be carried accurately and error free through any medium involves concepts beyond a basic understanding of the speed of light. But in the real world one will encounter reliable well designed wireless links and poorly performing wired links.
There's a clear misunderstanding here.
Light and wireless signals used by mice etc are the same thing though, just at a different frequency. They propagate at the same speed, the speed of light, which ironically is slower in glass.
Wireless signals in air travel faster than light in a fiber optic cable (and faster than electricity in copper).