(May 10, 2019 at 1:21 pm)Brian37 Wrote:(May 10, 2019 at 10:52 am)polymath257 Wrote: But again, make the distinction between life at the bacterial level (which I agree is most likely quite common) and life at the technological level. At this point we have no chance of detecting non-technological life beyond our solar system.
But, if there was a technology at the level of manipulating stars, there is a decent chance we could detect it. There was even a false signal recently thinking there might be construction of a Dyson sphere around a nearby star.
Detecting those 4 needles becomes a lot easier if they are luminous. The question is, if there are truly advanced technologies out there, why are they dark to us? And if not, why not?
Again, even life at our level would be likely too. But again, the universe is so big, it is still that needle/haystack for them and us.
Distance. While there could even be more advance life then ours, because of distance, it would most likely be just as stuck locally where it is, like we are, even if it had a slightly longer range. I will say this though, if I were intelligent alien life, and spotted us, with the way we behave to each other now, I wouldn't try to contact us even if I could. We are a very violent species.
I really do think you are over complicating this. It only takes water and amino acids for evolution to occur. As individual atoms, those atoms are plentiful in the universe. But no, I still do not buy any Area 51 or Roswell crap.
In theory if we could go to every rocky planet in the universe, as big as it is, we should expect to find life at our intellectual level. But again, distance and time and energy are going to make it almost impossible for life to communicate with each other over those distances.
Yes, it only takes a few common compounds to get life started (as far as we understand). But what I am saying is that even once we have life, that doens't imply the existence of complex cells, let alone intelligent life.
And I definitely don't agree that we should expect life at our level wherever we go. As an example, if you look at the Earth over the last 3.8 billion years for which it has had life, there has been *agriculture* for only the last 10,000 years or so (well, except for ants) and the use of radio waves for only the last 100.
If we take the Earth as an example, it would be *very* unlikely to find a technological species over the time it has had life. Even as a percentage of the time Earth has had multicellular life, humans have been around a very small fraction of that time.
What I would *expect* in going to a planet similar to Earth orbiting a star similar to the sun and at the right distance, is to see *bacterial* life primarily with a chance of complex cells. Much less likely is some form of land 'animal' and even less likely is something technological.
