Galaxy orbital velocities explained without 'dark matter' halos.

Discussion in 'Pseudoscience' started by nebel, Dec 19, 2014.

  1. Hayden Registered Senior Member

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    It is not in dispute, observed fact, that the outer stars are moving at a faster speed than the Keplerian maths suggest.

    In an orbital motion, the orbital speed is determined by the central pull, so any higher speed observation would call for either new physics or increased mass. MOND explains but changes Newtonian Physics a bit, other option which is widely accepted is dark matter. The distribution profile of dark matter still remains a subject matter of further research.
     
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  3. nebel Valued Senior Member

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    Keplerian math is based on a huge central mass, a star in a planetary system mostly void of matter, and galaxies of various configurations are far from that easy arrangement.
    In those cases of more even mass distribution, the shell theorems are more applicable and they show that here is more gravity on the outside than the inside every time. more gravity on the outside would show up in larger orbital velocity. For these small curvature outer orbits, acceleration by deviating from the tangent requires more distance travelled.
    It is just possible that dark matter might turn out to be a red herring.
     
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  5. nebel Valued Senior Member

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    Talking about Black Holes that have no inside:
    "--The gravity is in an enfolding surface tension--"


    Tracing the singularity from the beginning, in an " even " molecular cloud, all particles there would be in a balanced gravitational condition, but a lesser density with distance would start a squeezing by gravity from the outside, the area of lesser density. This warping of spacetime would propagate at the speed of light, and matter would be pushed by that pressure into the center, where gravity would always be zero, be balanced.
    Would the arrival of a singularity condition change that ? . The compression of matter leaves behind the gravitational field, long before the arrival of the EH or the singularity condition,
    gravity is a surface tension.
    There is much more gravity on the outside than any inside. orbital velocities show that, dark matter or not.
     
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  7. nebel Valued Senior Member

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    If you underestimate the required velocities, commensurate with an overestimated gravity, because of ignoring the near zero effective gravity in the interior, you are bound to over - estimate the required escape velocities on the outside, tempting you to add dark matter to explain what kept the "outriders" from spiralling away.
    Is not mass calculated by comparing inside and outside velocities?
     
  8. RainbowSingularity Valued Senior Member

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    how do gravity fields that over lap entire planets get zeroed out ?
    is this what some phrase as "collapsing the wave function" ?
     
  9. RainbowSingularity Valued Senior Member

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    like fungi ?
    they digest their food on the outside
     
  10. nebel Valued Senior Member

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    That is my question too. Not about "lapping over planets?" but
    It has been stated by others, that at the center of a body, where there is no effective gravity, because the surrounding mass balances out, pulling equally in all directions,-- at the centre, there really is double gravity, just that the balancing hides that fact, makes it un detectible, except through dime delation, if you could get at it. ( not my understanding) so:
    There is either no gravity, or double gravity that cancels out, at the centre. anyway,
    An equal density, perfect disk of loose matter, like a dream galaxy, would rotate like a solid disk, because gravity would exist in conformity with the shell theorem, zero at centre, no movement there, maximum velocity at the perimeter.
     
    Last edited: Sep 16, 2018 at 11:12 AM

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