100 years doesn't seem like a long time to me because of the age of our civilisation or species, it seems like a long time to me because of the lifespan of our

100 years doesn't seem like a long time to me because of the age of our civilisation or species, it seems like a long time to me because of the lifespan of our species. I certainly can't communicate at all on a 200 year RTT, as I'll be dead and forgotten before I get an answer. If it's communication, that implies a two-way exchange of ideas. The galactic equivalent of blogging would be like all such communications: typically of more interest to the sender than the receiver. If we assume a long-lived species that can receive a response within its lifetime, we must also assume that during the intervening time little enough of the context has changed that the answer is still relevant. That means a species and a civilisation that has extremely little change over hundreds of years. This is what I mean by an extraordinarily static civilisation. (But if it's so static, what could possibly be said that has material bearing on anything? :-)