[hattend]

Although unlikely, were a modern civilization found living on a planet orbiting Proxima Centauri, its proximity makes it a reasonable possibility that humanity could communicate with them.

Earth: hello there!

[eight years later]

Proxima Centauri: Who's this?

[eight years later]

Earth: We are Earthlings!

[eight years later]

Proxima Centauri: Who?

[eight years later]

Earth: Earthlings!!

[eight years later]

etc, etc, etc

Thrilling communications!

[SunkenCiv]

From the 1970s -- Thomas J Gold: "But I am not really willing to accept your premise, because it may well be that the means of communications they have are of a kind that we do not know how to receive, and that they would not have the means of communicating with sufficiently powerful radio or optical signals. That is something which, technologically, is too difficult for them but they would have some other means we would not recognize." and "What we can conclude from this is that we must think very widely as to what it takes to develop intelligence and not take us so much as a model of what is necessary." [Communication with Extraterrestial Intelligence, p 123; Sagan editor -- CETI was the old acronym]