I asked these questions before, can anyone help? Here are my ideas: Let's say that we get the solar system completely colonized. Settlements around Saturn, Jupiter, the asteroid belt, on Mars, the moon, heck even Mercury. But we never get beyond radio or microwave communication. How much energy will be needed for system wide communications? We would know exactly when we could send a message from here to there, would the signals be tight-beam? Even if the signals were constant, how much would leak, how easily could an easdropping civilization pick them just four light years away? Or father out? Just wondering if the failure, so far I hope, of SETI means that we are being very optimistic or a strong indicator that we are alone. I think Contact had Vega as the star where we were detected, 40 LYs away. Was Hitler's Olympic TV signal really that strong, how much above background noise would that signal be after 40 years? Don't remember if Sagen used the same contact method in the book.
For the same system wide communications, will lasers become more common? Won't a laser signal be that much harder to detect a few LYs away? We keep on raising the frequency of our communications, up to 2.4Ghz at least, will that make us more noticeable or less? When we get space telescopes capable of seeing earth sized planets around other stars, ten to twenty years, we will get a better handle on how often a water free planet occurs. But even if they are everywhere, it will be a long time before we have enough resources to send something to another star. Kevin Tarr Up way too late. Added: I don't think shooting lasers half way across the galaxy means diddly. It's such a point-source that it'd be tough to pick up, like seeing 'phasers from the Enterprise', from the side. We will get the quantum computer/messaging working sometime in the next thousand years, so 'radiation' communication will stop, or become that much quieter. But also we will find the signal 'busy': other life forms already communicating and telling us wait your turn! But heck, we could be the first. Someone has to be. A million years from now it won't hurt our ego to find we are truly alone in this galaxy, we'll just look at other galaxies and wonder about them. <Still up too late, time for bed>
