[QUOTE]It may never be empirically possible for any physical particle of mass, to travel at the speeds necessary, in order to bridge the awesome distances involved in interplanetary travel. This is likely to upset the 'dreamer' set, (not that I don't include myself in this category, also)./QUOTE]
Craig,
Phil Plait, in the same chapter that I mentioned yesterday, talks of a continual acceleration system like an ion drive which he seems to feel is within our grasp, not necessarily in our lifetime but not far away; the major hurdle being political will. He feels that using something like this can get us to every "habitable" planet within a relatively short space of time. By using a system of small probes dropped from the initial vehicle onto a suitable (mineral content wise) planet, these probes would then mine the metals from the planet and replicate the original spacecraft (See: Replicators on Stargate
). If it took 100 years from launch of any one probe to launch of offspring probe from the next planet, in 3000 years there are more than 1 billion (2^30) copies of our original probe exploring the Milky Way. Of course, the replicator part of the technology required would seem to be a fair bit further away than building an ion drive system.
Hopefully though, time is on our side. We have only been here for 200 000 years. Dinosaurs hung on for almost 200 000 000 years. So even if we only have a million years left to our reign on Earth, there's plenty of time to work stuff like this out.
I have to quote one of his footnotes from this chapter.
"Despite a zillion blurry photos, obvious fakes and shaky video, there has not been a single, unequivocal piece of evidence that we have been visited by aliens
ever. Deal with it.
Stuart