intra galactic empire
the basic premise of seti is that if there are intelligent civilizations out there they would be using a particular frequency to communicate across stellar distances. so seti has been listening to the hydrogen frequency for non-natural signals for some 50 years. a recent statement was that they would find something within the next 20-30 years or they won't find it at all. in which case there's something wrong with their fundamental assumption. ya think? heh. okay suppose i ran an intra-galactic empire. start on earth. over thousands of years i'd colonize my neighbors. which would be a sort of fire and forget thing. ie we keep sending colony ships until we get word back that one succeeded. sending energy from here to there is extremely expensive. there's no way we'd send communications as mundane as email. call your mother. heh. won't happen. communication would be limited to scientific and technological discoveries. possibly even the exchange of astronomic information. heh. imagine what astronomers might do with telescopes that have baselines of several lightyears. holy haleakala. we'd do that so we know where to colonize next. anywho, the communication would be a very tight beam. maybe using the sun or a planet to focus it. regardless, the signal is going to be extremely directional. simply because we could not afford the energy to broadcast in all possible directions. so the odds of earth lying in the path of an extraterrestrial communication are exceedingly small. that doesn't mean et's aren't out there. it just means that the seti search in its current form isn't going to find them.