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Hope for ET?

  1. Sep 10, 2015 #1


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    This paper: http://arxiv.org/abs/1509.02832, The Age Distribution of Potential Intelligent Life in the Milky Way, estimates the age distribution of intelligent civilazations in the Milky Way. Unsurprisingly we rank somewhat below the advancement level of termites compared to your typical ET. It is noted " By comparing the ages of these systems we estimated that 77% of potentially habitable star systems are on average 3.13 billion years older than the Sun." A civilization commensurably advanced to our own on such time scales should be easily capable of colonizing the galaxy. So, where are they? The authors note "it could be concluded that they [ET] most likely do not want their presence to be known to us yet, possibly for reasons beyond our current level of understanding."
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  3. Sep 10, 2015 #2


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    They might be dead too. Who's to say we're going to last for 3 bn years?
  4. Sep 10, 2015 #3


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    I agree with the authors to the extent that fathoming the motivations of an advanced ET may be beyond our current level of understanding. Considering the paradigm shifts that might occur with only a million or so years of further advancement reminds me of what an ant might think of an incredibly well lit spot on the ground just ahead. Focused sun light from a gigantic lens might not be among its guesses.
  5. Sep 10, 2015 #4
    Let's say there is a species 1 million years more advanced than us. They have greater technology than we have... but far less technology than a species 2 million years more advanced than us. So we're all in the same boat - no species knows whether or not they are the most advanced, and therefore cannot take the risk of venturing out into the universe.
  6. Sep 11, 2015 #5


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    Consider the second Iraq War. Our species has been unable to act rationally, with almost no exceptions, for its entire known history. I suspect irrational, emotional, drives, and a fundamental inclination to avoid learning from history are built in to our genes. It may be a catch-22. A country whose citizens act rationally will not find many (if any) causes worth fighting (dying) for. Such a country will be easily conquered by true believers surrounding them. I have little doubt that without fundamentally rational structure, no civilization can endure for 100,000 years. The fantasy speculations about the motives of any intelligence, including our own, on time scales of tens of thousands to billions of years is just plain infantile. I can not prove that there is no limit to technological progress, but I believe it. For instance, I believe we will never exceed the speed of light, and will never violate the Law of Conservation of Energy. If true, this means that there is no million year "gap" in technology. There are plenty of threads here discussing the rational answer to the question: why haven't we heard from "them"? Acting as a rational being, compute the pros and cons to contacting an irrational intelligent species. Boiling it down: pro is some (slight?) increase in knowledge; con is some slight possibility that they will be hostile with a non-zero chance their hostile actions could destroy our civilization (say a probe equipped with a biobomb). In a techno limited universe, there is little rational reason to make contact. When's the last time you ate a moldy rotting fruit just to see what happens? It might be good for you. I suspect that few intelligent species remain technological for 100,000 years. I further suspect that any rational civilization will either decide the economic costs of ET contact are too high or that the existential risks too great. Putting it another way, our lack of contact is extremely strong evidence that the Laws of Physics, as we understand them, are very good approximations to the actual way the Universe works: no warp drives, no worm-holes, no FTL drives, no transporters, no easy interstellar travel, no unlimited energy sources, no immortality treatments, ...
    Last edited: Sep 11, 2015
  7. Sep 11, 2015 #6
    You can still have a million year gap without faster than light propulsion. When humans first really learned how to sail the seas, we built colonies that would take months or years to access. I see no reason that vast distances between the stars is any factor. The only difference would be that it would prevent any sort of galactic empire, but individual colonies will sprout up every time there is a civil war or idealogical differences. Eventually of course, the descendants of these colonist will evolve into separate species.
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