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Should The Galaxy Have Been Colonized By Now?

  1. Oct 26, 2005 #1
    This topic brings up the Fermi Paradox, once again. I just want to hear the boards opinion on this...should the galaxy have been colonized by now? and a decent portion of it has been colonized would we able to "see" it?
     
  2. jcsd
  3. Oct 27, 2005 #2
    what if we're the first space faring civilization? The galaxiy would still be a very lonely isolated place. my point is it's impossible to tell at this moment.

    I doubt it, which brings me back to my first point, our technology is still very primitive.
     
  4. Oct 27, 2005 #3
    So we are still very much in the dark, is that what you mean?

    EDIT: What do you guys think of this quote

    "Quote from Freeman Dyson;
    "I have the feeling that if an expanding technology had ever really got loose in our galaxy, the effects of it would be glaringly obvious. Starlight instead of wastefully shining all over the galaxy would be carefully dammed and regulated. Stars instead of moving at random would be grouped and organized . . . So in the end I am very skeptical about the existence of any extraterrestrial technology."
     
    Last edited: Oct 27, 2005
  5. Oct 27, 2005 #4
    Yes, and in regards to astronomical engineering well lets just say that the technologies to accomplish some of those feats would require a lot of power and a lot of time (thousands or millions of years) But I very much doubt that anyone would bother going to all the trouble of arranging stars in an organized manner, seems to me there are more worthwhile goals to undertake, whatever they may be.
     
  6. Oct 27, 2005 #5

    Chronos

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    Agree with vast. Assuming our scientific knowlededge is even marginally correct, interstellar travel is too expensive to justify. Colonizing the galaxy to any appreciable extent could easily take many billions of years.
     
  7. Oct 27, 2005 #6
  8. Oct 27, 2005 #7

    Garth

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    As it will take 100,000 years or so to send a light ray across the MW I would say those figures are a little optimistic. Are you sure the '500 years' was not the estimated time to return to the Moon?

    Garth
     
  9. Oct 27, 2005 #8
    This is assuming, of course, extraterrestial civilizations even want to colonize the galaxy. For all we know they could be just happy just living on their home world.
     
  10. Oct 27, 2005 #9
    Yes, of course...or just their own solar system.
     
  11. Oct 27, 2005 #10
    Earth-like planets require a certain amount of galactic distillation to occur before such planets can form. First, an initial generation of stars have to cook up the heavy elements needed for rocky planets and life. These elements are spread around through supernova, and then another generation of stars has to form from the resultant dust. However, the inner part of the galaxy is too dangerous for life to exist very long: there are supernova constantly exploding at close range, and the density of stars and black holes would disrupt the orbits of any planets that form. Thus, only the middle and outer regions of the galaxy are suitable for life. But stellar evolution proceeds more slowly as one travels toward the edge of the galaxy because the mass density decreases. Consequently, Earth-like, rocky planets capable of supporting life will begin to form in a ring around the middle of the galaxy that spreads to the edge through time. Through an accident of galactic geography, we happen to be on the inner edge of this ring, which entails that we are among the first planets with life, and perhaps the very first planet in the galaxy to have human-style intelligence—as the negative results of the SETI project tend to bear out, sporadic reports of UFO’s notwithstanding.
     
  12. Oct 27, 2005 #11
    If that theory is correct then there still should be a couple dozen or more Earth-like planets with life on it with intelligence close to ours or maybe even surpassing us by a couple thousand years, even if it is still early in the game and we are the first wave, there should be more like us...theres just way too many stars.

    Even though I dont think the lack of alien signals points to this theory being correct.
     
    Last edited: Oct 27, 2005
  13. Oct 27, 2005 #12
    Well, if human-style or higher intelligence and culture is so easy to evolve, one or more species of dinosaurs should have evolved into a technological civilization. But this didn't happen, despite the fact that there were many bipedal species of dinosaurs with free forelimbs.

    Similarly, primates have been around for 10's of millions of years; if it is easy to evolve intelligence, there should have been another primate species that evolved long ago.

    Other contingencies also *could* have happened on Earth that would have made it much harder to evolve human-style intelligence; e.g., if the original vertebrate ancestor had gone extinct, there would be no vertebrates at all. On a planet with Earthly gravity, it is difficult to grow very large land arthropods, because of their external skeleton. Maybe lobsters or octopi could become very intelligent, but it would be difficult to get a technological civilization started in seawater.

    Of course, the other standard explanation for the great silence is that technological civilizations are extremely unstable and quickly blow themselves up. Thus, the odds of any two technological civilizations existing at the same time would be vanishingly small.

    Or perhaps there is one dominant, yet very stealthy civilization that destroys any new civilization that it detects, in order to preserve it's turf--and they're on their way. . . .
     
  14. Oct 27, 2005 #13

    Labguy

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    Yes, but if we are considering "civilizations" that can evolve, reason and use technology, it isn't just going to be limited to Earth-like planets. Not all possible evolutions are going to become two-legged, 5-foot 10-inch bipeds walking around with simply different patterns of bumps and spots on their heads, as in Star Trek.
    There could be creatures the size of a flea, breathing H2SO4 and flying in ships the size of a shoebox....:zzz:

    Yes, they are called the BORG, again as in Star Trek.
     
    Last edited: Oct 27, 2005
  15. Oct 27, 2005 #14
    Or maybe we are still very much in the dark, its not like we scanned the a decent portion of the galaxy already, there could be a civilization 1000 light years from us and we might not know it right now...and I never said developing human-like intelligence was easy but it did happen, even if it is rare there should be atleast a dozen or more like us because of how many stars there are. I dont think the great silence proves that there arent any aliens out there...atleast not yet.
     
  16. Oct 27, 2005 #15
    No that is quite unlikely. Aliens have to follow the laws of physics and something the size of a flea doesn't have the brain power to make a spaceships.

    Just so you know, the fact that there are a lot of stars in the universe, doesn't at all imply life is out there.
     
  17. Oct 27, 2005 #16

    Labguy

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    That wouldn't constrict the possibility of micro-neurons in micro-branes. The don't have to be built with cellular construction like ours. It is possible.:biggrin:
    Perhaps not, but here we sit contemplating the subject with computers. The huge number of stars in billions of galaxies makes it rather egotistical of our race to think that we are it; nothing else. "The stars and all the universe revolve around us", said Galileo to the inquisitor...:cry:
     
  18. Oct 27, 2005 #17
    Micro-"branes"--as in 11-dimensional p-branes?:confused: An interesting suggestion; but how could biological-like evolution through natural selection occur at such tiny scales? Think about Von Neuman's essential elements for *any* self-replicating system. What would be the mode of heredity? What would the bodies be like? How do branes control other branes? Can branes make copies of themselves? What would an ecosystem in 11-dimensional hyperspace be like? If it really is possible for branes to be intelligent, space-faring creatures, then where are they?

    So yeah, I still like Star Trek--at least the original version. I graduated from "Horton hears a Who" a long time ago. :bugeye:
     
    Last edited: Oct 27, 2005
  19. Oct 27, 2005 #18

    Labguy

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    I never said I could spell..:mad:
    Brane, Brain, Calabi-Yau loops??.:confused:
    Poor old Brian Greene and String theory don't have a chance.
    I graduated from infinities and singularities a long time ago.
     
    Last edited: Oct 27, 2005
  20. Oct 28, 2005 #19
    I never said it was impossible, just very unlikely given the knowledge we have, which it is. This is a forum of science, not science-fiction.

    Not egotistical, just illogical. And I think it was the inquisitor that said that to Galileo, not the other way around.
     
  21. Oct 28, 2005 #20

    Labguy

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    Yes, it is science, so wouldn't it be absurd to exclude things / properties / possibilities which we simply haven't discovered yet? Were Einstein, Oppenheimer, Chandra, Eddington, et al doing science fiction when considering the possibilities of strange objects like neutron stars and black holes? I think that it was ~1966 when the Crab pulsar was detected, a fair bit after the initial thinking and even the math regarding such strange objects. Chandra's Limit for example?
    No, Galileo had to say it to "recant", and then spend the rest of his life under "house arrest".
     
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