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Warp drive?

  1. Jan 4, 2009 #1
    I love Star trek and I was thinking, how to create a warp drive.
    I have read a discusion about EM waves on this forum, there was written that they do not need any medium for propagation and : “In a simplified sense the oscillating E field sustains the oscillating B field which sustains the oscillating E field ...“ Does it mean, that they do not affect space-time?
    Can space-time be affected or warped by quantum of energy (without weight), for example by photons?
    I taught that if we put a one way current pulses with enough energy and frequency to ship`s hull, the formed EM field could work as paddle in space-time. Couldn`t it?

    What would happen if the change of magnetic field, caused by current pulses, is faster than light?
    For example, if magnetic induction is 1Tesla 10meters from the hull, the wave length (or “impuse length“:) is 1meter, asuming that speed of current is close to speed of light, the magnetic field (the point with the induction 1T) would “travel“ 20meters, while the current (or light) 1meter.
     
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  3. Jan 4, 2009 #2

    jambaugh

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    In short yes. Einstein's field equations for gravitation have stress-energy as their source term. That is to say any energy will "bend space" not just mass.

    "quantum energy" is just "energy". The energy of a photon is no different than the energy of a bullet. Both will bend space-time and both can be used to do "useful" work.

    As far as using light as a "paddle", light has momentum and so emitting light has a recoil just like the above-mentioned bullet. This is called a photon drive or light drive in the science and science-fiction literature.

    The change of a magnetic field caused by anything always travels at the speed of light (in whatever the medium) since light is (electro-)magnetic fields and vis versa.
     
  4. Jan 4, 2009 #3

    DaveC426913

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    Regardless of what propulsion system you use: if your ship has mass, it will not reach - let alone exceed - the speed of light, so no warp speed.
     
  5. Jan 4, 2009 #4
    Clearly warp speed can be achieved by nothing less than a warp drive (such as the warp-bubble solutions of general relativity). :smile:
     
  6. Jan 4, 2009 #5

    DaveC426913

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    Well, yes, but I think the OP was thinking that his proposal was that of a warp-type drive. It's not though, it's still a propulsion drive.
     
  7. Jan 5, 2009 #6
    I agree, that the idea I have presented would not allow a ship to go faster than light, but
    the thing is, that the magnetic field (or better magnetic field waves - because it is magnetic field formed by one way a.c. current pulses "traveling" through the hull) moves as fast as light, so the ship would still accelerate towards the speed of light, although it can never reach it.
    According to relativistic theory, it`s weight will increase instead of speed.

    So it`s weight will grow and in some point it will reach a critical point, like a star which is too masive, it will break through space-time. With the propper mass (or some help :smile:) it could create a worm hole instead of black hole. Couldn`t it?

    Normaly, anything colliding with such a fast ship would destroy her, but if the magnetic field pulses could bend the space-time around the ship, then it would also work as a shield. (to the point, when it will create a worm hole) Am I right? :smile:
     
    Last edited: Jan 5, 2009
  8. Jan 5, 2009 #7

    ZapperZ

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    At some point, you need to re-read the PF Guidelines that you have agreed to. Pay particular attention to our policy on speculative, unverified ideas.
     
  9. Jan 5, 2009 #8

    DaveC426913

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    No. Relativistic mass does not cause an object to collapse into a black hole, only rest mass.
     
  10. Jan 5, 2009 #9

    Vanadium 50

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    ZapperZ makes an excellent point.

    I should point out that Star Trek, particularly in the post-1980's incarnations encourages a particularly distorted view of scientific theory: that it is just a matter of stringing together the right scientific sounding words in the right order. There's even a term for it: Treknobabble.
     
  11. Jan 5, 2009 #10
    What is the difference between relativistic mass and a rest mass?
    And how is it possible, that one can cause an object to collapse to black hole and the other can`t?
     
  12. Jan 5, 2009 #11

    ZapperZ

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    Please start by reading our FAQ in the General Physics forum on the entry on the mass of a photon.

    Zz.
     
  13. Jan 6, 2009 #12
    Thanks for your reply
    I have read the FAQ, but still I don`t understand why relativistic mass can not form a black hole.
    From a non-expert point of view, I would say that both relativistic mass and rest mass "press" on a space-time, one because of moving too fast and the other by weight, so why is the outcome different?
    Does it mean that even very concentrated energy can not bend the space-time?
     
  14. Jan 6, 2009 #13

    jambaugh

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    Space-time is bent but in a covariant way (transformable between observers traveling at different velocities). A nice technique in relativity for answering questions about moving objects is to ask the question about the stationary object and then transform the answer to the moving observer's frame.

    In the case of relativistic mass, consider that in the frame moving with this mass no black hole would form (because in that frame it is just sitting there with a small mass) and thus no black hole would form in any frame.
     
  15. Jan 6, 2009 #14

    DaveC426913

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    As jam points out, note that in the frame of reference of the spaceship, there is no mass increase experienced.

    In fact, who are we to say that the whole Solar System isn't, at this very moment, travelling at .9999999999c with respect to some external observation point? Yet, we would certainly be surprised if the Solar System suddenly collapsed into a black hole for no readily apparent reason!
     
  16. Jan 7, 2009 #15
    What is the relativistic mass, if it is not actually a mass? Isn`t it derived from
    the equation F=m.a? (if the force can not cause acceleration, then it has to cause a gain in the weight) Or isn`t it actually a curvature of a space-time, which is said to be a relativistic mass?
    Does anybody know why is there a "speed limit" in our universe? Or what causes it?
     
  17. Jan 7, 2009 #16

    ZapperZ

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    Please restrict your question to just one thing. The question on the limit to c is and has been discussed in several threads in the Relativity forum. Try looking in there first!

    Zz.
     
  18. Jan 7, 2009 #17

    DaveC426913

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    Mass is relative to your frame of reference
    No. That's Newtonian mechanics, which is a good (OK, excellent) approximation of the sitch at non-relativistic speeds. To examine time, space and mass in an arena where relativistic speeds are common, use relativitistic equations. Here's a sample calculator.
     
  19. Jan 8, 2009 #18
    Thanks
    I suppose, I should at first learn something more about the theory:)
    Would a collision of a particle (or small meteorite) with a ship, traveling for example .999999 speed of light, be possible?
     
  20. Jan 8, 2009 #19

    DaveC426913

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    Sure would. In fact, it would be virtually impossible to avoid.

    And, yes, it would be bad. In fact, it would leave 'bad' lying in the dirt, choking on its dust.
     
  21. Jan 9, 2009 #20
    Might I ask why one would believe that it isn't possible?
     
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