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Possible Explanations To Fermi's Paradox?

  1. Jul 14, 2005 #1
    I think we can all agree that no alien civilization has made contact with us yet, but does this really mean we are alone in the galaxy?
     
  2. jcsd
  3. Jul 14, 2005 #2
    Possibly, but not necessarily. There's a book that speculates on answers to Fermi's question, Where is Everybody? by Stephen Webb, but I haven't read it and I don't know how good it is. It's an entertaining question to think about, but you will not find any definitive answers.

    I suspect that highly intelligent life may be relatively rare, that interstellar travel is impractical, and that the lifetimes of technologically advanced species may be limited by adverse natural events and/or the tendency towards self-destruction. But what do I know?
     
  4. Jul 14, 2005 #3

    mathman

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    Not only has no one made contact with us, but we haven't made contact with anyione else. As cragwolf suggests, it is hard to get from here to there.
     
  5. Jul 14, 2005 #4

    amt

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    So for now we can conclude that we are alone and hence, we must celebrate life to the fullest! :biggrin:

    My theory: If we are alone, then we are the result of Intelligent Design.
    If there are others, then we are the result of Billions of years of on going evolution in a never-ending chain reaction of constantly evolving Universes.
     
  6. Jul 14, 2005 #5
    Even if there were 50 highly advanced alien civilizations, they still could be separated by 4,000,000,000 stars on average...and if there were 100, they could be separated by 2,000,000,000 stars
     
    Last edited: Jul 14, 2005
  7. Jul 14, 2005 #6
  8. Jul 14, 2005 #7

    tony873004

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    Imagine if other intelligent life is so far advanced that we wouldn't recognize it if it were staring us in the face.

    Think of how much more advanced we are than a colony of ants. If humans inhabited a previously uninhabited island, and tried to make contact with the ants I doubt we could. I doubt the ants would be rubbing antennas telling each other that humans have arrived and are communicating with us. They'd just see us as an obstacle to be worked around, no different than a tree or a turtle.

    Imagine an alien civilization so far advanced that they need not take precautions to hide their presence. We wouldn't know they existed if they waved their arms in front of our faces.

    Imagine if stars and planets were actually alive. We see them as just balls of rock or gas. But our brains, to an outside observer, aren’t much different than 5 pounds of ground chuck. The chemistry inside stars and planets may be much more complicated than we imagine, playing host to intelligence and consciousness. We'd never know because we're looking for biology.

    Not necessarily my opinions... Just trying to play devil's advocate... :devil:
     
  9. Jul 14, 2005 #8

    Chronos

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    I think the tightest constraint is how long a communication capable civilization can survive. We have only been communication capable for a matter of decades, but are imminently imperiled by our own technology. We could bomb ourselves back to the stone ages [or worse] in the blink of an eye. We are also imperiled by potential ecological disasters of our own making that could do an equally fine job of 'stoning' civilization [or worse]. Based on the one example we do have to examine, I don't think life or intelligence is nearly as rare as it's ability to avoid self destructing shortly after acquiring the capability to do so.
     
  10. Jul 15, 2005 #9

    turbo

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    It's a sobering (actually depressing) thought, but in our society the motivations and efforts of decent ethical people can be undone by those who lust only for power and control. These maniacs realize that through lies, manipulation, etc, they can acquire the means to destroy life, destroy societies, etc. Usually, they fill their rhetoric with words like "freedom", "liberty", and "security", while they work very hard to deny these things to entire classes of people, sometimes entire societies. Eventually, careless use or intentional use of the destructive capabilities controlled by these sociopaths may spell the end for the human race. For this reason, the Drake equation should contain a term for the ethics of the intelligent species. In a truly ethical society, all life would be valued and individuals would act in a manner consistent with the Golden Rule. In a moralistic society, in which behavioral motivations are derived from rules, religious tradition, political doctrines, laws, etc, almost any atrocious act against another individual can be "justified". I fear that the long-term survival rates of moralistic societies will be rather poor compared the the survival rates of ethical societies.

    I'm sorry to wander so far into philosophy, but I feel that the capacity for self-destruction is an important factor, and the motivations of the people wielding the most power of self-destruction are of critical importance.
     
  11. Jul 15, 2005 #10

    tony873004

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    Let me argue the other side.

    I don't think we could bomb ourselves to the stone ages if we tried. An all-out nuclear war doesn't have the kill power to eliminate everybody. It might kill most, but there are not enough nukes to bomb the countless populated rural areas, many of which are not downwind from a major target. The lack of infrastructure would take a big toll amongst those that survived the nuclear war. But there's lots of people on Earth, and the most resourceful would find a way to survive. In fact, it might thin the gene pool to only the most intelligent.

    Even if the conditions were stone age afterwards, the survivors are people from technologically advanced civilations, not cavemen. Once intelligent life gets a taste of technology, there's no turning back. It may take 2 or 3 or even 10 generations, but we'll have cell phones and space shuttles and starbucks coffee again.

    As far as an ecological disaster...
    Man survived the ice age. Global warming has happened before, probably many times in the history of mankind, and mankind has survived. Mankind has survived droughts, floods, etc. Even in the most dire global warming scenarios, Canada will still be pleasant.

    And unlike any other species on Earth, man has the ability to deal with asteriod and comet threats.

    Mankind is resourceful. Mankind is here for a VERY long time.
     
  12. Jul 15, 2005 #11
    So all aliens have human tendencies?...the tendency to harm to each other?
     
  13. Jul 15, 2005 #12
    What if the aliens were very resourceful and just took what they needed? not populate the whole galaxy, tell me just because they arent here does that mean they dont exist? I see alot of people are saying "well they arent here yet so they probably dont exist"

    Another question has the Milky Way galaxy allowed enough time for life to evolve and populate the galaxy?
     
  14. Jul 15, 2005 #13

    EnumaElish

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    Absence of evidence is not evidence of absence.
     
  15. Jul 15, 2005 #14
    Yeah, you basically summed up what I felt about the paradox, although the paradox does proves that technological civilizations IS NOT abundant..
     
  16. Jul 15, 2005 #15

    ohwilleke

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    I think that we are less advanced over a colony of ants than we would like to believe, if the colony as a whole, rather than individual workers are viewed as the organism.
     
  17. Jul 16, 2005 #16

    Chronos

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    My point is/was [and much in agreement with turbo], we have been dangerously close to catastrophe [all out nuclear war] at least once in the measly ~half century we have been technologically capable of communicating with extrasolar civilizations. Assuming 'survival of the fittest' is a universal caveat for life, the tendency to destroy competitors for the 'top of the food chain' award is hardwired. Technololgy makes us more efficient assasins. A thousand years ago, a single 'terrorist' could only take out a handful of people. But with access to the right technology, a modern 'terrorist' could take out millions. With another thousand years of technological advances, is it so far fetched to think a single, technologically enabled individual could take us all out? The Fermi paradox suggests we might be well advised to get our priorities straight.
     
  18. Jul 17, 2005 #17

    turbo

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    You don't need to kill everyone with blast effects and radiation...Sagan et al thought that as few as 100 nuclear weapons (especially ones targeted on smoky targets such as oil facilities)would be enough to trigger a nuclear winter that would destroy most species. I would estimate that there are probably 200-500 times that number of nukes in the arsenals of the Earth's industrialized countries.

    http://www.sgr.org.uk/climate/NuclearWinter_NL27.htm

    Photosynthesis drives most of this planet - even the largest whales in the ocean rely on phytoplankton for food. Some life would survive, but it would be a bit of a setback to have to start repopulating Earth with Sulfur-loving tube worms thriving around volcanic vents at the bottom of the ocean. OK, some land life might survive - my bet is on cockroaches and perhaps Keith Richards (nothing else has seemed to be able to kill him!). :rolleyes:
     
    Last edited: Jul 17, 2005
  19. Jul 18, 2005 #18

    Garth

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    Bang on target!

    Various religions over the centuries have warned of impending doom, the judgement of God on humankind, it seems to me that in our generation God has given us the means to judge ourselves...

    Garth
     
  20. Jul 18, 2005 #19
    Turbo-1,

    While, the nuclear winter that article describes is certainly horrible, I'm not convinced that such a disaster would wipe out humanity. It makes a comparison to the Cretaceous extinction which wiped out 75% of species. That means that 25% of species survived. Many mammals, reptiles, amphibians, fish and birds survived it - why couldn't we?

    Given time our destructive technologies will undoubtedly improve. I guess I'm hoping though that other technologies that may increase our odds will be developed in time like space exploration/interstellar travel.
     
  21. Jul 18, 2005 #20

    turbo

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    The original group that posited nuclear winter (including Sagan) thought that 100 well-placed nuclear devices would be enough to trigger the cataclysm. The US alone has 100 to 200 times that many nuclear devices, and when you add in Russia, China, GB, France, Pakistan, Israel, etc, etc...well, you can do the math (provided the quantitative estimates in the publicly-available literature are even OOM accurate). I think any hope that humanity might survive a massive nuclear exchange is ambitious but mis-placed. The small percentage of surviving species would likely be those sheltered by deep water, earth, etc and least reliant on photosynthesis for food.
     
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