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FTL Communication in an Interstellar Civilization

  1. Dec 3, 2015 #1
    There are lots of sci-fi settings in which Mankind has become an interstellar civilization and lives on numerous planets throughout its galaxy.

    However, if the fastest we can communicate is at the speed of light, we will have to wait ages to receive a message between planets.

    Does this mean that we'll never be able to become an interstellar civilization no matter how hard we try?
  2. jcsd
  3. Dec 3, 2015 #2


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    Depends on how long we try.

    Btw, I like your signature. :smile:
  4. Dec 3, 2015 #3
    Haha, true.
    In the past, it would have taken us months to conduct this very discussion.

    Now, it takes less than a second.

    But there's no way I could have (or want to have) a discussion with someone who lives on a planet 10 light years away.

    That's a problem that has plagued science throughout the ages.
  5. Dec 3, 2015 #4


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    We can have an interstellar civilization, but it will be nothing like what you see in "Star Wars". This is probably a good thing. Civilizations around different stars would need to be completely autonomous. I would imagine that if you had two planets 10 light years apart, each would continuously broadcast their news, and receive the other's news 10 years later. You could have discussions, they would just be of a different nature.
  6. Dec 3, 2015 #5


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    If you live 70 years, then 10 years is pretty much. But if, in the future, genetic engineering will allow us to live, say, 7000 years, then 10 years will not longer look so much.
  7. Dec 3, 2015 #6
    Also, we're supposing that Relativity will hold for a long time from now...

    If we can speculate with such hypothetical cases, we may think of exotic ways of communication. So, my answer would be:

    If our basic understanding of space and time doesn't evolve, yeah, we're doomed. But we can also hope that this won't be the case, uh? :D
  8. Dec 3, 2015 #7
    It was completely out of sight that we could fly to the moon like Jule Verne described in his time. Never imaginable possible. And so it will be with subspace/Hyperspace communication
  9. Dec 3, 2015 #8
    This woke something in my memory and Google helped me find it:

    Thank you, Google.
  10. Dec 3, 2015 #9
    I would expect our journey outward to go very similar to the way that we colonized Earth in the 1700s. We'll probably create colonies on far away worlds, under basic law of the host planet, but those planets would eventually declare themselves sovereign. I'm hopeful that there is some strange inherent properties of the universe that will allow us to warp between world easily and quickly, but it doesn't look like it with our current understanding of physics, nor have we seen any evidence of anyone else doing it.
  11. Dec 3, 2015 #10
    Slightly different cases though.
    In the time of Jules Verne flying to the Moon was not contrary to known physics, it was unimaginable from an engineering perspective.
    Hyperspace communication DOES violate well established physics, it's beyond being just a problem of not having developed the required technology.
    It assumes at least one additional dimension of space which is invisible to us, (that is literally what the word 'hyperspace' means).
    There is no reason to suppose additional dimensions of space exist.
    String theories invoke possible higher dimensions of space at submicroscopic scales, but afaik these don't imply ftl communication,
    and string theories are not so far supported by any observation, they are purely mathematical abstract ideas.
    Last edited: Dec 3, 2015
  12. Dec 3, 2015 #11
    Well, you can also think of 1900s. By that time, with the known and well stablished physics, it was just non-sense to propose something like the laser or Nanotechnology, to cite just a few examples.

    In my point of view, we will surely discover an entire new realm of physics when we can probe higher energy scales. So, maybe in a few centuries, this post will be an obvious one too :) .
  13. Dec 3, 2015 #12
    You should be more optimistic ;-)

    In history well established physics was always naiv old believing system. The earth is middle of the universe and we only can think of ideal circles for the planets around the earth incl sun. This was established more than 1000 years ;-) And it worked! It was in time more and more complicated but all Astronomers could calculate with it and were always proving that this must be the right theory.
    That the sun was in the middle and that we doesn't have ideal circles was completely nonsense for the people in their time.

    We have now similar phase in history of mankind.

    Or think of the Loge of phytagoreer who could prevent for 100 years that we have inkommensurability with numbers and cannot describe with natural numbers the diagonale of 5 star. 100 years later there must have come Plato to publish that the natural number is not all and that it was criminal to hide this from the academic world only to say that they have the right established physics (mathematics and philosophy was physics in this time)

    Or think of GRT. Before Newton was enough and worked more or less. Then came Enstein with an idea which was completely out of imagination for the established physics. The world should not be described with euclidic geometry? Must be completely nonsense.

    I could write a book about all these cases what established physics was. ;-)
  14. Dec 3, 2015 #13
  15. Dec 3, 2015 #14


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    Relativity is basic to the structure of the universe. I think it is very unlikely that it will change. In what way does slow communication between stars make us "doomed"? 300 years ago communication between Europe and North America took months, perhaps a year. Do you think people felt "doomed" as a result?
  16. Dec 4, 2015 #15


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    Perhaps relativity will remain true, but the value c of the velocity of light will change?
  17. Dec 4, 2015 #16
    I said "doomed" because communicating is useful as long as it responds to treating problems of any kind. If you want to communicate with a civilization which is 50.000 light years away, my guess is that it will be, being optimistic, a boring "conversation"...

    In the NA and Eu comparison that you're proposing, the speed of light makes that distance an irrelevant obstacle (it wasn't fundamentally difficult to communicate, only technologically).

    Also, even if you consider Relativity to be the right and ultimate description of reality, you will have to admit that it fails strepitously on a quantum scale of length. There maybe you can argue that you'll learn many new things about the fabric of spacetime itself (and maybe come up with ideas of how to use them...)
  18. Dec 5, 2015 #17
    America became independent as a result. With interstellar distances and increased speed of technological and social development this would result in entirely different civilizations.
  19. Dec 5, 2015 #18


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    I agree. I view this as a good thing. It will probably even result in entirely different species.
  20. Dec 5, 2015 #19


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    Given that no one here seems to be in the process of writing science fiction and needing help with it this thread breaks the SF sub forum rules.
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