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Why would aliens come here

  1. Feb 10, 2005 #1
    If aliens could come to earth, they would need some extremely high tech spacecraft; so high tech in fact that they would seemingly be quite far ahead of humans in technology. With that said, why would an alien come here? It would be like humans studying cavemen; less intelligent and less advanced. There are some people who study cavemen, anthropologists, but most people dont care about cavemen because they are inferior in many ways. The only thing that makes sense to me is if it was humans from our future looking back on history like a tv show.

    And another seperate but related comment. If our radio signals have only reached about 100 stars thus far and we are waiting to hear back from them- does this not make sense to anyone else? The second humans established radio technology, they would have been picking up alien radio signals if they were being emitted on purpose or not. Thus i conclude that aliens are not using radio signals anywhere near earth; not only within the zone in which they could hear our signals, but far far beyond if their civilization was developed for a long time.
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  3. Feb 11, 2005 #2


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    Good arguments. Our most primitive EM emissions are barely 100 years old. They are also too weak to even be detectable by any known means. Our more powerful and recent emissions have barely traveled more than a few decades. What are the odds of an equal or better society detecting them? ... nearly zero by the most optimistic estimates. Basically our SETI signals, if immediately responded to, have only gone about 50 light years. A mere pittance. Even given the most optimistic results for the Drake equation, it is highly unlikely our signals have reached any civilization capable of responding.
  4. Feb 11, 2005 #3
    As Perry Farrell said: "We'll make great pets".
  5. Feb 11, 2005 #4
    You could ask the same question about ourselves. Why are we sending such expensive equipment to Mars to see if there is any basic form of life?
    You are right that they wouldn't be interested in our technology, but there are a lot of other things, not only about us but also our environment, that would be worth studying.

    And as for the radio signals. Why would we notice alien radio signals if these came from an advanced race? These signals could be highly encrypted or whatever and for all we know what we are detecting is noise. Because as you stated if there is a more advanced race than we are, why would they want to communicate with us?
    And if there are aliens 'near' to earth, it doesn't mean that they didn't hear our radio signals, they just might not have responded to it. It's not because we don't know about them that they don't know about us. If there are more advanced beings out there, they probably don't want us to know about them.

    I am not saying that I believe in it, I'm just not excluding anything.
  6. Feb 11, 2005 #5
    it isnt whether or not they want to reply, atmospheres allowe for a certain amount of radio frequency leakage; they couldnt help but emit signals. And even if they now have more advanced communication, the signals from long in their past would still come to earth and as i said we would be picking them up the second we got radio technology. So i conclude again, aliens are not anywhere near earth.

    What kinds of things would decay a radio signal in space? just the fact that they are expanding spherically and thus depleting themselves?

    Pets, yes. Its hard for intelligent beings to treat lesser beings with respect. Look at how smart people treat the simple minded.
  7. Feb 11, 2005 #6
    Evolution and consciousness and the development of a society is a fascinating thing. For any race. Think about it. You could watch and observe another human like race to see how they evolve and develop. We have evolved one way and think one way and our social structure is set up this one way around our world. Our every day life and technology as mundane as it may seem to us could be unfathomable to another race that evolved and developed differently.

    No doubt an alien race would be much more techno advanced then we would be if they could travel here. But perhaps humans could give another insight to other ideas, art, music, entertainment they never have thought of before. Vice versa…
  8. Feb 11, 2005 #7


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    No doubt any life bearing planet would be of great scientific interest. Who knows what unique enzymes or DNA might be found. The possibilities are endless. And a planet with sentient life would be even more interesting in a variety of fields - sociology, arts & humanities, culture. But I really think a highly advanced society would treat us like a wildlife refuge - No trespassing. See ranger for tour schedule. Do not feed the animals. No littering. Remain cloaked and stay on the bus at all times.
  9. Feb 11, 2005 #8
    wow i read an intelligent well balanced thread on physicsforums...*spits out tea
  10. Feb 13, 2005 #9
    (Shhh! We're trying to lure in the aliens by pretending there's intelligent life here. If they see you sitting there with tea all down your t-shirt they'll think we're a planet full of dribblers who say "wow" a lot and post inane remarks :biggrin: ).
  11. Feb 13, 2005 #10


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    Why do you think alien life would be DNA coded?
  12. Feb 13, 2005 #11
    That is when you assume that their more primitive signals didn't reached us already long ago.

    But I'm not so sure about the fact that we would be able to detect their radio signals... Thus you are claiming that on Mars we would detect radio signals coming from earth?
    The power of that signal weakens by the square of the distance from the starting point. It would require some sophisticated signal processing to distinguish it from noise. It would have to be detected preferably with satelites in space and certainly not with amateur radio systems.
  13. Feb 13, 2005 #12


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    Not so much thay would necessarily be DNA based, rather it would be the obvious way for them to retrieve samples and grow their own back home, if desired. I would not, however, be very surprised if alien life was DNA based, or something very similar. It's molecularly simple and low overhead. The fact that every known living thing on this planet is DNA based implies it is efficient. I see a high probability than any life form that wide arise and evolve on an earth-like planet would use a similar, if not the same strategy. It would, of course, be a different matter if life arose and evolved in a very dissimilar environments. I'm not convinced that is possible, at least for complex organisms like people. It is hard to conceive a life form that is not carbon based. No other element is known capable of forming the diverse and complex molecular chains necessary for life like ours, and the environmental window amenable to such is fairly narrow.
  14. Feb 17, 2005 #13


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    Science? Conquest? Mining? Curiosity? Accident? Some other alien attribute that compels them to explore?

    FWIW, humans from 50,000 years ago were likely just as intelligent as modern humans.

    Many humans are fascinated with studying "inferior" life forms and/or history. As noted earlier, we're even spending billions of dollars on studying lifeless places in the solar system.

    But aliens are not human. They may have totally different motivations and sensibilities than we do.

    We're not really expecting to "hear back" from anyone. We (SETI) is listening for alien signals (intentional or not) independent from our calls/noise broadcast to the universe.

    Have we searched the billions of radio signal "channels" (frequencies) coming from every point in the sky? No. You can't use 1 radio receiver and expect to take it all in. Carl Sagan compared it to searching for a signal on a car radio (non-digital) except that the dial extends from here to the moon*. Try searching that extent of frequencies for every star in the galaxy and then factor in time (speed of light/signal limitations).

    * Although there is some focus on more likely frequencies to cut down on search time.
  15. Feb 22, 2005 #14


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    Not all living things on this planet are DNA based. Some bacteria are RNA based. The fact that all living beings we know are RNA/DNA based is a strong evidence that humans, oak trees and bacteria share a common ancestor, not that this is the only one or the more efficient coding system.
    As for being carbon based, I agree with you. Although some other elements are capable of forming long strings necessary to life, carbon is without doubt the more efficient.
  16. Feb 22, 2005 #15
    Leading slightly astray: What are the other elements that could be capable of life? Silver and silicon?
  17. Feb 22, 2005 #16


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  18. Feb 22, 2005 #17


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    There is something I didn't know. Any examples? I've heard speculation that RNA based life may have preceded DNA based life, but not that any currently exist.
  19. Mar 16, 2005 #18
    what about synthetic life. a carbon based life form developing synthetic based polymers to form a more complex and inherently superior form of life?
  20. Mar 18, 2005 #19
    Why would aliens come here?

    Well, ive read quite a few abduction stories, so just for the moment assume they are true, then these are apparently some of the things aliens want from us:

    -take our sperm
    -implant devices into us
    -create hybrids
    -research our souls
    -save our planet (from evil beings, from self-destruction)
    -merge our universe with another dimension

    There are probably many more theories around than these few.
  21. Mar 18, 2005 #20
    Thats an interesting one. They are taking our sperm, engineering our genes, and making stupid/highly motivated/strong slaves for some place.
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