A radio observatory on Earth might be using a fiber optic connection to connect to the rest of the world but it's still looking at natural radio phenomena. It d

A radio observatory on Earth might be using a fiber optic connection to connect to the rest of the world but it's still looking at natural radio phenomena. It doesn't matter at all what a civilization might use as a backhaul, their Space iPhones could use SubspaceWifi, but their radio observatories will be looking at natural molecular hydrogen emissions. For an interstellar beacon signal radio is pretty good. Lots of natural phenomena are radio sources, CMB is radio, and a lot of things opaque to visible and near visible light are transparent to radio. So a radio beacon has a good chance of being detected just because any civilization that discovers radio astronomy can stumble across it. The idea that SETI would ever detect I Love Lqwynngh'tch reruns from an ETI has always been ludicrous. Even our most powerful radio telescopes (by sensitivity) wouldn't be able to detect television or radio broadcasts even a lightyear out from Earth. The only interstellar signal we (or another civilization) will ever detect are very intentional directed signals. If you had an omnidirectional radio source detectable from interstellar distances you could use it once as it would fry itself and anything around it pretty quickly.