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Re: Physicists Howl at Dark Matter

Subject: Re: Physicists Howl at Dark Matter
From: Lester Zick
Date: Sun, 10 Sep 2006 11:43:45 -0700
Newsgroups: sci.astro, sci.math, sci.physics, sci.skeptic
On Sat, 9 Sep 2006 21:08:15 -0400, "G. L. Bradford"
<glbrad01@xxxxxxxxxxxxx> wrote:

>
>"Lester Zick" <dontbother@xxxxxxxxxxx> wrote in message 
>news:4kg3g21udu7uup94aef0gmg2lqf6cig1fh@xxxxxxxxxx
>> On Fri, 8 Sep 2006 05:04:28 -0400, "G. L. Bradford"
>> <glbrad01@xxxxxxxxxxxxx> wrote:
>>
>>>
>>>"Lester Zick" <dontbother@xxxxxxxxxxx> wrote in message
>>>news:48n0g2hep0q9sl6omnov4omrlhn4hh4kli@xxxxxxxxxx
>>>> On 24 Aug 2006 11:12:59 -0700, "Aluminium Holocene Holodeck Zoroaster"
>>>> <QncyMI@xxxxxxxxxxxx> wrote:
>>>>
>>>> [. . .]
>>>>
>>>> I had a curious and irreverant thought the other night prompted by an
>>>> interview with the "discoverer" of dark matter to explain a supposedly
>>>> anomalous constant velocity of rotation for matter in the Andromeda
>>>> galaxy regardless of radius from the center. It seems according to her
>>>> explanation that velocities should fall with increasing radius because
>>>> gravitation is an inverse square force whose effect should decrease in
>>>> proportion.
>>>>
>>>> So my thinking wandered to the question of whether a flat disk should
>>>> also produce such an effect. Obviously it would where gravitationally
>>>> attractive matter is concentrated at the center as in the case of the
>>>> sun or planets considered as attractive centers because the amount of
>>>> gravitationally attractive matter would not increase as a function of
>>>> distance from the attractive body.
>>>>
>>>> However this would not be true for flat disks of uniform density
>>>> gravitationally attractive matter. The amount of gravitationally
>>>> attractive matter would increase as the square of radius from the
>>>> center just offsetting the inverse square decrease in the strength of
>>>> gravitational attraction leading to a constant velocity overall.
>>>>
>>>> The effect is analogous for mechanical explanations for why inverse
>>>> square gravitationally contracted spheres such as the earth by and
>>>> large rotate as a single object. For in this case the amount of matter
>>>> increases as the cube of distance from the center. And since the force
>>>> of gravitational attraction falls in inverse square proportion to that
>>>> distance, the ratio between matter and force becomes a linear function
>>>> of radius or distance from the center of rotation. Thus the velocity
>>>> of rotation increases roughly in linear proportion to the radius and
>>>> all matter thus constrained rotates more or less in unison.
>>>>
>>>> Now this isn't to suggest that matter in the Andromeda or any other
>>>> galaxy is in fact distributed in a flat disk of uniform density.But in
>>>> point of fact the analysis presented by the discoverer of dark matter
>>>> treated the problem as if the entirety of gravitationally attractive
>>>> matter were concentrated at the center of the galaxy instead of
>>>> distributed in some considerable proportion throughout the galaxy.
>>>>
>>>> It seems absurd that this kind of mistake could happen in physics. Yet
>>>> this is exactly what analysis of the issue requiring the existence of
>>>> "dark" matter suggested. Basically the velocity of matter at some
>>>> distance from the center of the galaxy should be expected to fall in
>>>> proportion to the square of distance since gravitation is an inverse
>>>> square force. However velocity remains roughly constant. Therefore
>>>> some kind of "dark" matter must exist to make up for the discrepancy.
>>>>
>>>> Maybe I'm misreading the situation on the basis of an uncritical
>>>> popular documentary and maybe such considerations have already been
>>>> acknowledged and discounted. However it is very tempting to see the
>>>> supposed demand for "dark" matter to compensate for the inverse square
>>>> decrease in gravitational attraction as nothing more than the effect
>>>> of a more or less uniform density galactic disk instead.
>>>>
>>>> ~v~~
>>>
>>>  Brian Greene in his The Fabric of the Cosmos has an illustration in the
>>>book of a galaxy inside a huge ball of dark matter. This supposedly helps 
>>>to
>>>keep galaxies from flying apart, or fraying at the outer fringes of the 
>>>disk
>>>to death. I've read elsewhere our galactic disk might be twice its 
>>>diameter
>>>(200,000 light years across rather than 100,000) if one included unseen
>>>outer fringes of dark matter. This would stretch Greene's ball shape into 
>>>a
>>>second and far larger [shell] galaxy shape in which the known, seen, 
>>>galaxy
>>>would simply be the inner and smaller galaxy en-shelled inside a outer and
>>>larger hyperspatial, you might put it, Milky Way galaxy.
>>>
>>>  Since the outer fringe of the seen Milky Way is at tremendous velocity 
>>> and
>>>should be being thrown away from the galaxy because the known gravity of 
>>>the
>>>Milky Way should not be holding onto that fringe, what would be holding 
>>>all
>>>that shell and extra diameter to the galaxy other than an overall gravity
>>>very much greater than the gravity we realize. A very much greater gravity
>>>that would not be realized unless and until velocity was very much
>>>increased, say by a traveler in the galaxy accelerating in velocity to
>>>prodigious velocities relative to the Earth. Such velocities that would
>>>shrink the galaxy in upon him until it became a much more solidly unitary
>>>mass entity than the much more loosely packed highly dispersed mass entity
>>>we see and know. Such velocities as would force the traveler up and out of
>>>the known Milky Way galaxy -- as if he were escaping a massively 
>>>increasing
>>>gravity of gravity well -- if he wanted to keep on accelerating up in
>>>velocities for some reason, yet still live to do it.
>>>
>>>  He is up and out of the Milky Way he knew before and traveling faster 
>>> than
>>>ever. But is he really out of the Milky Way? Or is the Milky Way a
>>>hyperspatial two or more level galaxy? GR's "principle of equivalence,"
>>>along with QM's principle of uncertainty, suggests he might now be 
>>>relative
>>>to essentially the same galaxy in the universe but now one entirely
>>>different than the one he knew before in its makeup of stars, star 
>>>systems,
>>>clusters, all other entities and phenomena. The one he knew before now
>>>having shrunk more into the center mass of this one he isn't traveling
>>>nearly so fast in now -- relative to it in time.
>>>
>>>  Did those very high velocity fringes of the Milky Way close in and slow
>>>down vastly in velocity relative to the traveler's once very high velocity
>>>now highly unrecognizable as such? Did the dark matter shell pick up where
>>>everything the traveler knew of the Milky Way galaxy before left off? Pick
>>>up as a second and different Milky Way galaxy relative to the traveler 
>>>now?
>>>A different Milky Way galaxy's matter and masses, including atomic, that 
>>>the
>>>traveler per his continuous acceleration up in velocities might now 
>>>acutely
>>>match velocities with per GR's equivalence principle, possibly QM's
>>>principle of uncertainty as well, in addition to possibly other quanta
>>>dynamics (if any)?
>>
>> Personally I don't know what the distribution of velocities is in the
>> Milky Way. What I do know is what was reported for the Andromeda
>> galaxy of an anomalous constant velocity distribution by the woman who
>> was credited with the discovery. That only requires a flat disk of
>> constant mass distribution. (By the way, I would appreciate it if you
>> don't alter the alist since the arguments I present are mathematical
>> and not purely physical or observational.)
>>
>> ~v~~
>
>  The arguments pertain to the "purely physical or observational." And 
>Andromeda is not a flat disk of constant mass distribution. That is quite a 
>bulge in the center. And the outermost edge is far more frayed in detail and 
>focus than is the rest of it going away from the edge toward the center, not 
>uniformly sharply clear and defined like a CD's entirety of surface and 
>edge; its unity of acutely matched horizons in general. That correlates 
>outside into Andromeda -- with some few twists for distance and 
>angularity -- with what we observe of the Milky Way's differences in 
>distributions and velocities inside to even more inside, and inside out to 
>the edge, from our position in the Milky Way's disk.

I never suggested there weren't irregularities in the distribution of
matter in galaxies. But according to the documentary the suggestion
was that velocity distribution in the Andromeda galaxy should fall off
according to the inverse square law of gravitational attraction. And
that would be incorrect if the distribution of mass were approximately
uniform and circular. I just don't know what if any corrections were
made to account for density irregularities and what if any allowances
were made for the approximately disk like distribution of matter.

>  I thought the mathematical, in this specified context, was supposed to 
>describe something more or less, not nothing...more or less. I thought is 
>was supposed to synchronize with the physical or observational more or less. 
>More or less mapping, or painting the picture of, the physical or 
>observational. But I know from experience now that mathematical phyicists do 
>enjoy taking the one dimensional from an indivisible multiple dimensionality 
>and isolating it to complete independence, warping all projection from it 
>out of all sane logic. Then teach or indoctrinate to the world in general, 
>especially the children of the world in general, that insanity of isolated 
>dimension, and of fantastically unreal projections in dimensionality made 
>from such complete isolation, as the indisputably unquestionable reality of 
>the world or Universe.

Not sure what you're talking about or what it has to do with the
subject at hand. My mathematical rationale was simply that the inverse
square law of gravitational attraction in disk like galaxies should be
more or less exactly compensated for by a proportional square increase
in the amount of gravitationally attractive matter producing an
expected constant velocity distribution overall.

>  Each of all of you tend to deny responsibility for the today's ever more 
>general dark age of formal education to lazy ignorances, stupidities and 
>mindless thoughtlessness. The more fiercely you try to hold on to very 
>unreal isolations from very real indivisibilities the more unsane (sic) the 
>real world around you will grow and close in upon you in it.

I don't deny anyone anything except dialectical philosophy.

~v~~

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