Your views are very objective Lex and you allow for the possibility that we don't really know how life can exist because we are limited to our own understanding of the laws of physics that we understand. I have often said that at some point we may realize that life is all around us and has been for a very long time. We simply did not have the ability to perceive it. In cases where a species is say a thousand years more advanced than us, that may account for the unidentified flying objects that people have seen (obviously with only a small percentage of those being unexplainable like the tic tac incident), yet what about a civilization that is a million or a billion years more advanced than us. What would that look like? We really don't know. Beings that could exist in multiple dimensions or universes. Perhaps like the movie Space 2010 where the beings are primarily made of light (or energy and have no real form). Godlike abilities that far supersede our own. Able to manipulate energy in ways that make them almost omnipotent. We think of civilizations as being Type 1, 2, 3 or 4 but we really don't know. They may have the need or no need to spread throughout the cosmos or galaxy. They would easily be able to cloak their existence from us. Really insightful Lex and more importantly you allow for the unknown.