General Discussion
In reply to the discussion: UFOs exist and everyone needs to adjust to that fact [View all]Spider Jerusalem
(21,786 posts)first: space is incomprehensibly vast. The nearest star with a potential terrestrial exoplanet is 4.3 light years away. Faster-than-light travel is not so far as we know something that is possible; at speeds known to be attainable by (uncrewed) spacecraft, a journey of 4.3 light years' distance would take over fifty thousand years.
Second: even if intelligent alien species with advanced technology wouldn't be too far away to reasonably ever visit Earth, the odds that they exist at all are also extremely low; so far as we know, humans are the only species, out of many millions, to have emerged on earth in the 3.9 billion year history of life on this planet to have the capacity for advanced technology; there's genetic evidence that suggests most of our species has gone through significant population bottlenecks that probably represent near-extinction events, so the fact that we're still here now is somewhat improbable, and we're presently in the process of hastening our own extinction through our addiction to fossil fuels (which may prove to be an issue for any similar alien civilisation that develops advanced technology along simiilar lines; see the idea of the "Great Filter").