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Intergalactic Traveling Methods

  1. Apr 10, 2004 #1
    for any science-fiction type interplanetary colonization to take place (i'm talking large scale like Star Wars or Star Trek) we first need a more efficient method of travelling. so, in your opinion, which of the many ideas out there is most promising. Examples are WORMHOLE TRAVELING, the HYPERSPACE or SLIPSTRING thingy, DIMENSION SKIPPING, REALLY LONG VOYAGES ON REALLY BIG SHIPS, etc. (if there are any that i've forgotten please fill me in)

    ~a pondering nerd

    P.S.: should i make i poll?
     
  2. jcsd
  3. Apr 10, 2004 #2

    LURCH

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    I should think that travel from one Gallaxy to another would not happen unless some way can be devised to make use of whatever phenominon is behind quantum entanglement. A form of teleportation.

    For interstellar travel within this gallaxy, really long voyages in really big ships seems most probable, as the other methods are not known to be possible, but this method is.
     
  4. Apr 12, 2004 #3

    chroot

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    It's a pity that quantum entaglement, at least as presently understood, cannot transmit any information.

    - Warren
     
  5. Apr 13, 2004 #4
    Until we achieve faster then light travel i dont think anyone is going to bother exploring jack.
    Long space travel just isnt feasable or even worth it because by the time the people got there we probobly would have devised a faster method and overtaken their wasted journey anyways.
    Maybe 200 yrs we'll figure it out...

    Saw on tv some scientist guy says hes actually sent sound waves through time. apparently some quantum wormhole. sounds about as promising as the photon teleportation. next time i mutate into a photon itll come in handy.
     
  6. Apr 13, 2004 #5
    By quantum entanglement, I assume you mean quantum inseperability?

    It'd be amazing to have such a system across the universe! I'm guessing that one person would download himself to the quantum inseperability/entanglement hub, and be created somewhere else. The advantages of this would dwarf ordinary (light-speed limited) teleportation; Both trips are instantaneous to the 'loader, but the Q-S/E method is truly a to b stat.

    Over and out.
     
  7. Apr 13, 2004 #6
    Why not, if I may ask? My understanding of this subject is very limited to say the least, but I was under the impression that quantum entanglement means that changes to one of two entangled quantum systems will instantly be reflected in the other system. So why can't this be used to transmit information? Are you saying that it is technically impossible at the moment, because of our limited technology, or that it is not theoretically possible and never will be?
     
  8. Apr 13, 2004 #7

    selfAdjoint

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    It's an importaant point that quantum mechanics does predict the entanglement but also does not allow information to be sent using it. The real handicap is that any observation of either particle breaks the entanglement. So if you twiddle one of the paricles to send a bit, the entanglement is then broken and you can't do any more with that pair. But at the other end, the measurement of the (now unentangled) other particle can't tell if it was originally in one state ot the other. It takes two observations to do that.

    It's only "after the fact" that you can collect statistics on many pairs and observe that the states of the separated particles are more correlated than classical physics would predict.
     
  9. Apr 13, 2004 #8
    Gravimetric Engines very well could get up to near light speeds so fast that the travel is near instanteous aboard the ship, but of course outside the ship time would progressse normally :(.
     
  10. Apr 13, 2004 #9
    I realize that once you "read" the information you break the entanglement, but is it still possible to send information? If we just want to send the information of one bit, could we? And then to send larger blocks of information you would need more entangled system, but theoretically is it possible?
     
  11. Apr 13, 2004 #10

    Nereid

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    You may have the tiniest inklings of what might, in time, become a cool way to transmit information. Why not take the time to develop the idea further? Describe, in some detail, how you in Israel, on planet Earth, can transmit information to my twin, on an Earth-look-alike planet, circling a G-type star in M31?
     
  12. Apr 13, 2004 #11

    selfAdjoint

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    Nereid and Chen,

    How do you tell at the far end which particle switched? You get a random spread of (let us say) spin orientations over zillions of particles (i.e. one end of zillions of pairs). Somewhere in that white noise is a bit, but where?

    I used to think you could line up all the pairs to spin along some preselected axis. But that is a measurement and destroys the entanglement. There is a theorem that says you can't amplify a given spin orientation, i.e. take one pair and produce zillions of copies (or even one copy) spinning the same way. So the pairs you are given are randomly oriented.

    Suppose as someone here has suggested you arrange a filter that blocks all but one orientation. We can think of it classically as a narrow gate; any particles spinning up or down with respect to the gate will pass and any other particles will be blocked, giving us a mono-oriented beam. We can send a bit by destroying that orientation for one particle which automatically also destroys it for the entangled other. These randomly oriented particles would stand out in the mono-oriented background. Trouble is, I am pretty sure that in the quantum world, the initial filtering would count as a measurement, even on the "passed" particle. I don't have a proof of this but I am pretty sure it's true.
     
  13. Apr 13, 2004 #12

    chroot

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    At the "sending" end of the quantum-entanglement communications link, you cannot control which spin (either up or down) your entangled particle will wind up with. As a result, you cannot control which spin the entangled particle on the "receiving" end of the link will come up as. You can only transmit random bits.

    It'd be a great way to create and transmit a one-time-pad though!

    - Warren
     
  14. Apr 14, 2004 #13
    Are you trying to mock my admittedly limited knowledge on the subject, or what? :confuse: Because if you are, I really fail to see the point.
     
  15. Apr 14, 2004 #14

    Nereid

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    No, and I apologise if it came across that way. :redface:
     
  16. Apr 14, 2004 #15

    Janitor

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    Not nearly as exotic as the suggestions above-

    In his Space Odyssey novels, Arthur Clarke was dealing with "mere" interplanetary travel within the solar system. All but two of his human characters were put into some sort of cold-storage state, where their metabolism was slowed down to a crawl. Maybe in a few hundred years there will be technology to do this, but I would imagine it would only be practical for voyages of months, not centuries. I think Clarke's interplanetary vehicle was powered by nuclear fission heating a liquid to plasma and ejecting it at high exhaust speed.
     
  17. Apr 20, 2004 #16

    mee

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    Big ships Long time

    yep. yep. yep.
     
  18. May 2, 2004 #17
    What about sending Morse Code signals FTL? You wouldn't worry about detailed information - either the signal (entangled particle) is sensed or it isn't...
     
  19. May 2, 2004 #18

    selfAdjoint

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    No information FTL in quantum mechanics. You have to abandon standard QM to get FTL (such as Bohmian mechanics).
     
  20. May 3, 2004 #19
    That's not nessecarily true. In some cases, quantum effects produce FTL phenomena. For example, squeezed vacuum states and Casimir-type effects (ie, the so-called "zero-point energy") all create negative energy, which can be used in things like the Alcubierre drive or the Krasinov tube, both of which are FTL metrics.
     
  21. May 3, 2004 #20

    selfAdjoint

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    Quantum mechanics is not yet mated to general relativity, which is where the Alcubierre solution of Einstein's equations has its being. The use of the Casimir effect to meet the negative energy requirements of Alcubierre is purest speculation. Zero point energy is also. There is no true transfer of information FTL within proper quantum mechanics.
     
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