> I did used to entertain the idea of communicating near instantly over great distances. > And then I better understood the stupendous energy requirements to s

> I did used to entertain the idea of communicating near instantly over great distances. > And then I better understood the stupendous energy requirements to shout/yell/make noise for a two-way round trip of sound waves from one county to the very closest neighboring county. And it is just not practical, even for a civilization at he end of the technology development tree (as known to us 1k years ago). If we were to look at communicating via radio waves with the technology of the ancient Greeks, they might wonder how we could possibly shout loud enough to be heard so far away. And why, if visits from another world were possible, would everyone know? If I found myself in ancient Greece and talked over a walkie talkie, it would be the same as something with crazy advanced travel technology just stopping by on their safari trip through our solar system.