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Thread: A Question about Gravity

  1. #1 A Question about Gravity 
    Forum Junior DrmDoc's Avatar
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    Hello All,

    I am considering a quantum theory of brain function and I have a question about the nature of gravity. My knowledge in this area is limited, but if I understand correctly, gravity is essentially the effect of mass on the fabric of space/time; i.e., gravity is the warping or curvature of space/time by mass. If so, does this suggests that space/time, as a field of energy, flows around rather than through mass? And if this is true, does this suggest that mass is a repulsive force to space/time?


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  3. #2 Re: A Question about Gravity 
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    Quote Originally Posted by DrmDoc
    Hello All,

    I am considering a quantum theory of brain function and I have a question about the nature of gravity. My knowledge in this area is limited, but if I understand correctly, gravity is essentially the effect of mass on the fabric of space/time; i.e., gravity is the warping or curvature of space/time by mass. If so, does this suggests that space/time, as a field of energy, flows around rather than through mass? And if this is true, does this suggest that mass is a repulsive force to space/time?
    no and no.


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  4. #3  
    Reptile Dysfunction drowsy turtle's Avatar
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    The cause of gravity cannot be explained by currently accepted mechanics. Some theories describe it as the 'curving of space-time', however this is a method of viewing the effects of gravity, rather than a literal model of how gravity is caused, since 'space-time' is poorly defined.
    "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." ~ Douglas Adams
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  5. #4  
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    Quote Originally Posted by drowsy turtle
    The cause of gravity cannot be explained by currently accepted mechanics. Some theories describe it as the 'curving of space-time', however this is a method of viewing the effects of gravity, rather than a literal model of how gravity is caused, since 'space-time' is poorly defined.
    I appreciate your helpful comments. If I may inquire further, how does physics discribe the force that causes the attraction between particles in space? I recall a program on planetary formation that used the attraction between salt crystals in space as an example of how planets may form.
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  6. #5  
    Reptile Dysfunction drowsy turtle's Avatar
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    It is described, but not explained, by the equation:



    Where F is the forcse, G is the gravitational constant (6.67x10^-11), r is the distance between the two bodies, and m1 and m2 are the masses of the bodies.
    "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." ~ Douglas Adams
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  7. #6  
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    Part of this discussion is missing or has been deleted. Perhaps this is where it should end.
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  8. #7  
    Reptile Dysfunction drowsy turtle's Avatar
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    I think it's just the plagiarism, and my response to it, that is missing. I'm happy to [attempt to] answer any further questions you have.
    "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." ~ Douglas Adams
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  9. #8  
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    I appreciate your insight and continued patience with my further queries. If I may further ask, what, if any, is the relationship between gravity, strong and weak atomic force, and electrostasis?
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  10. #9  
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    Post concerning personal theory moved
    "Men are apt to mistake the strength of their feelings for the strength of their argument.
    The heated mind resents the chill touch & relentless scrutiny of logic"-W.E. Gladstone


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  11. #10  
    Reptile Dysfunction drowsy turtle's Avatar
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    Quote Originally Posted by DrmDoc
    I appreciate your insight and continued patience with my further queries. If I may further ask, what, if any, is the relationship between gravity, strong and weak atomic force, and electrostasis?
    There are similarities between the way the forces appear to act, but really there is no apparant relationship between the forces themselves. Seperate mechanics are used to describe each force (although the mechanics that explain gravitational and electric fields are extremely similar).
    "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." ~ Douglas Adams
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  12. #11  
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    The similarity between gravity and electrostasis mechanics has piqued my interest. I will most certainly investigate this aspect further. Again, my sincere thanks for the insight you've shared.
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  13. #12  
    Reptile Dysfunction drowsy turtle's Avatar
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    No problem.

    The similarities, basically, are that both involve infinite-range fields which decrease by the inverse square of the distance between the two masses/charges in question. As such, you can use the same formulae to describe them, although with different constants.

    The main differences between them, really, are that electric fields both repell and attract, depending on the charge, whereas gravitational fields only attract, and the effect of magnetic fields on charged particles (and vice versa), compared to no effect on mass in magnetic fields.
    "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." ~ Douglas Adams
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  14. #13  
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    Quote Originally Posted by drowsy turtle
    The cause of gravity cannot be explained by currently accepted mechanics. Some theories describe it as the 'curving of space-time', however this is a method of viewing the effects of gravity, rather than a literal model of how gravity is caused, since 'space-time' is poorly defined.
    Nothing could be farther from the truth.

    Spacetime in general relativity is quite well defined. It is a 4-dimensional Lorentzian manifold. The curvature of that manifold is determined by stress-energy tensor which is determined by the Einstein field equations. Once those quantities are known all gravitational effects, so far as we know, are completely determined. The predictions of general relativity have been confirmed in a mutitude of experiments.

    The big problem is that the equations are, in general, not solvable in closed form. It is also true that GR is not compativle wiht quantum mechanics and in situations in which both gravity and QM are important, we have no viable theory.
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  15. #14  
    Reptile Dysfunction drowsy turtle's Avatar
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    OK, maybe I just don't understand how it's defined then :?
    "The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." ~ Douglas Adams
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  16. #15  
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    Quote Originally Posted by DrRocket
    Spacetime in general relativity is quite well defined. It is a 4-dimensional Lorentzian manifold. The curvature of that manifold is determined by stress-energy tensor which is determined by the Einstein field equations. Once those quantities are known all gravitational effects, so far as we know, are completely determined. The predictions of general relativity have been confirmed in a mutitude of experiments.

    The big problem is that the equations are, in general, not solvable in closed form. It is also true that GR is not compativle wiht quantum mechanics and in situations in which both gravity and QM are important, we have no viable theory.
    Your curt initial response, "no and no", belies the measure of your apparent insight. Why weren't you as detailed and forthcoming from the beginning? I should think that a person of your apparent intelligence would have little patience, as do I, for inane commentary and responses. What thoughts have you on the nature or relationship, if any, between gravity and electrostasis?
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