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B The bizarre rotation of galaxies

  1. Nov 14, 2017 #1
    The planets rotate around our sun faster and faster the closer they are.The Suns rotate around a black hole in a galaxy as if they were a record on a record player.Gravitational laws as we understand them don't seem to apply.Is it possible that a black holes gravitational pull not only freezes light from our perspective but also freezes time?
  2. jcsd
  3. Nov 14, 2017 #2


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    HUH??? What makes you think that? Gravitational laws as we understand them EXACTLY explain all that. Also, you have your facts wrong. Stars orbiting a black hole are generally (possibly all) in long elliptical orbits, not circular like on a record player.

    Now that's just silly. You yourself just said that we can see the stars in orbit around a black hole (which we can) so how could that be if time were frozen?
  4. Nov 14, 2017 #3


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    @Wallsy I see from other threads that you have posted here before regarding your lack of understanding of cosmology in general and orbital mechanics in particular. You would be well served to read up on this stuff systematically instead of asking semi-random questions on an internet forum.
  5. Nov 14, 2017 #4
    It's also worth noting that the galaxy does not orbit the black hole in the same way that the planets orbit the sun. The sun is a thousand times more massive than everything else in the solar system combined. The SMBH is the center of the Milky Way is significantly less massive than the rest of the galaxy.

    Anyway, the answer is that there is additional stuff in the galaxies that we can't see called dark matter. We know it exists by various means (not just the orbital velocity problem) but we don't have any maths that can describe what it is yet.
  6. Nov 14, 2017 #5
    Yes, the vortex rotation of these galaxies you describe, is a bit strange. Have you noticed - that the best, clearest example of this type of rotation appears to be associated with the galaxies classified as ... Barred Galaxies. Go look up pictures of this type of galaxy. (They're very beautiful, photogenic.)

    Now normally this rotation would be classified as a 'Rankine Vortex', with an inner, central Forced Vortex rotation component, and a second, outer, Free Vortex Rotation component.

    In these galaxies, the Forced Vortex rotation is as expected ... but the Free Vortex rotation section does not have the correct rotation velocity signature. Instead of having the normally expected, 2'nd order, power decay equation/line ... the decay is almost non-existent - almost horizontal.

    So, it is really the outer portion of the vortex that is not performing as expected. Its orbital velocity is way too fast - for the amount of visible matter present.

    Astronomers came up with a solution to this problem - called 'Dark Matter'. It has real magical properties.

    The Forced Vortex portion of the Galaxy's vortex, has another Physical property that must be considered and looked it. The Forced Vortex 'conserves angular rotation' ... the old picture of the beautiful ice skater speeding up or slowing way down depending upon if she extends her arms outwards or pulls them vertically up along her rotating z-axis as close as possible.

    What this means is that a Barred Galaxy is probably not operating in steady-state mode. Instead, it is slowly decaying ... which in this case means that every time the central Black Hole swallows and eats one of its orbiting stars - the Forced Vortex, to conserve angular rotation ... ejects a star or star mass, off of the ends of the central Bar-of-Light.

    This conserves the angular rotation rate and energy of the Forced Vortex. Meanwhile, the ejected star(s) fly outwards. Then, according to orbital rotation mechanics - flow backwards.

    Look at the pictures of Barred Galaxies again. See this "flow of stars" ... as 'two', beautiful, spiral arms ... One off of each of the two ends of the Light Bar ... as the stars flow upwards and backwards.

    Last edited by a moderator: Nov 14, 2017
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