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[Fwd: Dark Matter: black hole frame drag?]
On Mar 6, 11:46*am, josephus wrote:
Mike Williams wrote: Wasn't it Double-A who wrote: I don't know about the clustering, but the frame dragging influence from a massive black hole might affect the galaxy such that the galactic spin might appear to be faster than what gravity could account for, if the rotation of the black hole were in the same direction as the galactic rotation. *And isn't this exactly what is being observed? What is being observed is that the rate of decrease of rotation speed as you move out from the centre of the galaxy is less than one would expect if most of the mass is concentrated at the core. If ALL the mass were concentrated at the core, then the periods of stars in the galaxy would obey the same rules as planets orbiting the Sun, where the square of the period is proportional to the cube of the radius. The mass of a galaxy isn't all concentrated at the core, and this changes things so that the orbits in the outer regions are faster than that. By observing how fast the outer orbits are compared to the inner orbits we can determine that most of the mass of the galaxy is in the galactic halo, where there are few stars and few obvious places for that mass to reside. I don't know much about frame dragging, but I suspect that it would tend to affect the core regions far more than objects at the edge of the galaxy. This might possibly fit what's going on if the black hole is more massive than we would otherwise think, and rotates in the opposite direction from the rest of the galaxy. Thus the speed of stars in the halo would be mainly driven by gravity effects, but the speed of stars near the core would be reduced. However, it seems very unlikely to me that so many observed galaxies would happen to have counterrotating black holes, since infalling stars would tend to spin up the black hole so that it rotated in the same direction as the galaxy. there is a back of the envelope equation * * 1080/p * where p = A(1-e^2) * * * it is related to the frame draggin near massive objects. * *josephus -- I go sailing in the summer * *and look at stars in the winter Its not what you know that gets you in trouble * *Its what you know that aint so. * -- Josh Billings Wow! A thread revived from 2004! Can't do that with Google! Double-A |
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[Fwd: Dark Matter: black hole frame drag?]
On Mar 7, 12:29*pm, Double-A wrote:
On Mar 6, 11:46*am, josephus wrote: Mike Williams wrote: Wasn't it Double-A who wrote: I don't know about the clustering, but the frame dragging influence from a massive black hole might affect the galaxy such that the galactic spin might appear to be faster than what gravity could account for, if the rotation of the black hole were in the same direction as the galactic rotation. *And isn't this exactly what is being observed? What is being observed is that the rate of decrease of rotation speed as you move out from the centre of the galaxy is less than one would expect if most of the mass is concentrated at the core. If ALL the mass were concentrated at the core, then the periods of stars in the galaxy would obey the same rules as planets orbiting the Sun, where the square of the period is proportional to the cube of the radius. The mass of a galaxy isn't all concentrated at the core, and this changes things so that the orbits in the outer regions are faster than that. By observing how fast the outer orbits are compared to the inner orbits we can determine that most of the mass of the galaxy is in the galactic halo, where there are few stars and few obvious places for that mass to reside. I don't know much about frame dragging, but I suspect that it would tend to affect the core regions far more than objects at the edge of the galaxy. This might possibly fit what's going on if the black hole is more massive than we would otherwise think, and rotates in the opposite direction from the rest of the galaxy. Thus the speed of stars in the halo would be mainly driven by gravity effects, but the speed of stars near the core would be reduced. However, it seems very unlikely to me that so many observed galaxies would happen to have counterrotating black holes, since infalling stars would tend to spin up the black hole so that it rotated in the same direction as the galaxy. there is a back of the envelope equation * * 1080/p * where p = A(1-e^2) * * * it is related to the frame draggin near massive objects. * *josephus -- I go sailing in the summer * *and look at stars in the winter Its not what you know that gets you in trouble * *Its what you know that aint so. * -- Josh Billings Wow! *A thread revived from *2004! *Can't do that with Google! Double-A Due to gravity and subsequent photon distortions, there's almost no telling what we're looking at. It's like our universe is nothing but a cosmic fun-house that's full of those distortion mirrors, false dimensions and only the photon ghost(s) of whatever used to be. BH gravity is simply affecting the surrounding dark matter by continually expanding and compressing it, as well as subsequently speeding and slowing photons, whereas gravity itself remains instantaneous because the amount of mass within the universe has supposedly never changed from the very get go. There now, once and for all everything is resolved. Save your money on this one, because we could easily outspend trillions in our hard earned loot, and decades from now be no closer if not further away from the truth. btw, where the hell are those 70+ million year old seans when we need them? (I forgot, they're all lost in space) ~ BG |
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