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Antigravity like soluctions of Einstein equations

  1. Feb 15, 2006 #1
    http://arxiv.org/PS_cache/gr-qc/pdf/0505/0505099.pdf

    Franklin Felber says in this paper that for the first time has obtained the solution of the orbits of a particle near an ultrarelativistic central field (in second order of aproximation).

    This leads to the gravitomagnetic aproximation and to some kind of gravitatory repulsión in certain circunstances.

    Theoretically if some favorable celestial body (star) would be found that would allow drastic restrictions in the fuel necessary to acerlerate a ship to near of light speeds.

    Well, ¿do you think it is really worthin or simply NASA publicity? (the author works for NASA).
     
  2. jcsd
  3. Feb 16, 2006 #2

    Mk

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    Exact solution of gravitational field equation

    http://www.physorg.com/news10789.html
     
  4. Feb 17, 2006 #3

    pervect

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    Staff Emeritus
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    If you have to wind up inside the event horizon of a black hole to utilize it, "antigravity" just isn't going to be very useful.

    I do suspect that it is possible to gain some energy from a passing relativistic black hole via gravity without running into the event horizon, but the paper unfortunately doesn't make it very clear how this would be done. And it probably does not involve "antigravity" in any event.

    What's really annoying about this is not the paper itself, but the associated irresponsible PR that's being encouraged by the authors and "peer reviewers".

    Here is an example of the sort of statements that I think are irresponsible hype:

    If I want to hitch a ride to Alpha Centuari via a passing black hole without being crushed by the singularity, this paper doesn't make it clear how to do that. Getting in front of the BH just isn't a Good Idea.

    There is also a (perhaps fortunate) lack of relativistic black holes passing near the Earth in any event, so working out the details of how to "hitch a ride" wouldn't be all that useful in any pragmatic sense.

    BTW, having a "peer reviewer" associated with the "Institute of Advanced studies" (i.e Puthoff, et al) is NOT a good thing if one wants one's work to be taken seriously by the mainstream.
     
  5. Feb 26, 2006 #4
    ....at speeds where a speck of dust in your path becomes the mass of a boulder!:eek: Yea, real 'safe':biggrin:
    Not to worry...it has been ''rigorously tested'...:rofl:

    I wonder how many specks of dust you will encounter between here and Mars?:tongue2:
     
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