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  #1  
Old May 31st 06, 06:33 AM posted to sci.space.science
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Default Dark Matter

Does anyone have any personal theorys on what exactly the dark matter
of the universe is?

  #2  
Old June 5th 06, 12:52 PM posted to sci.space.science
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Default Dark Matter

Winnifred wrote:
Does anyone have any personal theorys on what exactly the dark matter
of the universe is?


Either an illusion [1] or matter we haven't spotted yet, like uncounted
brown dwarf stars, neutral hydrogen, etc.

[1] Regarding the "dark matter is an illusion," some recent models of
galactic motion have been able to replicate galactic motion without
dark matter using known principles of gravity and general relativity:
http://arxiv.org/PS_cache/astro-ph/pdf/0507/0507619.pdf

Mike Miller

  #3  
Old June 6th 06, 10:25 PM posted to sci.space.science
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Default Dark Matter

I'm just an undergrad EE major, but with some serious interest in
space. As to what Dark matter is, well, in my mind, the far more
interesting question is, what is dark energy. Dark matter is likely
just stuff in the form of small black holes, sub atomic particles, etc,
which massively adds up. Dark energy, well, that's just wierd,
something's emitting energy that we can't directly see, but affects the
gravitational pull of the uniververse... THAT'S something!

Winnifred wrote:
Does anyone have any personal theorys on what exactly the dark matter
of the universe is?


  #4  
Old June 9th 06, 10:16 AM posted to sci.space.science
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Default Dark Matter

wrote:
[1] Regarding the "dark matter is an illusion," some recent models of
galactic motion have been able to replicate galactic motion without
dark matter using known principles of gravity and general relativity:
http://arxiv.org/PS_cache/astro-ph/pdf/0507/0507619.pdf

That work (by Cooperstock and Tieu) assumes a highly implausible model
of the galaxy.

Notably, Korzynski (http://de.arxiv.org/abs/astro-ph/0508377) and
Vogt and Letelier (http://de.arxiv.org/abs/astro-ph/0510750) showed
that the Cooperstock-Tieu model necessarily also contains a "domain wall"
in the galactic plane (which would have to be made of either cosmic
strings or struts with a negative energy density). There's no
theoretical or observational support for this.

Garfinkle (http://de.arxiv.org/abs/gr-qc/0511082) gives a strong
argument that the nonlinearity of general relativity will not solve
this problem of the Cooperstock-Tieu model, but instead will make
it even worse.

Moreover, Cross (http://de.arxiv.org/abs/astro-ph/0601191) argues that
the Cooperstock-Tieu model is in fact internally inconsistent, and
Fuchs and Phelps (http://de.arxiv.org/abs/astro-ph/0604022) point out
that the Cooperstock-Tieu model strongly disagrees with the observed
local mass density and vertical density profile of our galaxy.

I wouldn't put much stock in the Cooperstock-Tieu model.

ciao,

--
-- "Jonathan Thornburg -- remove -animal to reply"
Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut),
Golm, Germany, "Old Europe" http://www.aei.mpg.de/~jthorn/home.html
"Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral."
-- quote by Freire / poster by Oxfam
  #5  
Old June 9th 06, 07:30 PM posted to sci.space.science
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Default Dark Matter

Jonathan Thornburg -- remove -animal to reply wrote:
I wouldn't put much stock in the Cooperstock-Tieu model.


I don't put much stock in it.

I just like the idea that there are alternatives to mysterious dark
matter and dark energy. It usually seems that when science has to start
invoking such handwavium, the observations are being misinterpreted and
there's a simpler answer.

Mike Miller

  #6  
Old June 13th 06, 01:40 AM posted to sci.space.science
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Default Dark Matter

In article . com,
"Tuvas" wrote:

I'm just an undergrad EE major, but with some serious interest in
space. As to what Dark matter is, well, in my mind, the far more
interesting question is, what is dark energy. Dark matter is likely
just stuff in the form of small black holes, sub atomic particles, etc,
which massively adds up. Dark energy, well, that's just wierd,
something's emitting energy that we can't directly see, but affects the
gravitational pull of the uniververse... THAT'S something!

Winnifred wrote:
Does anyone have any personal theorys on what exactly the dark matter
of the universe is?



My personal theory is that dark matter & energy is stuff that has gone
thru a black hole and come out the other side; from (x,y,z,t) to
(a,b,c,d). It is a Big Bang in an 'alternate' universe.

--
Free men own guns, slaves don't
www.geocities.com/CapitolHill/5357/
  #7  
Old June 14th 06, 01:11 AM posted to sci.space.science
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Default Dark Matter

Maybe Dark Matter or Dark Energy isnt really dark at all. like the
picture that is too close for our eyes to distiguish color-maybe the
darkness we see is something our eye's/brains are not equiped to
process.
Nick Hull wrote:
In article . com,
"Tuvas" wrote:

I'm just an undergrad EE major, but with some serious interest in
space. As to what Dark matter is, well, in my mind, the far more
interesting question is, what is dark energy. Dark matter is likely
just stuff in the form of small black holes, sub atomic particles, etc,
which massively adds up. Dark energy, well, that's just wierd,
something's emitting energy that we can't directly see, but affects the
gravitational pull of the uniververse... THAT'S something!

Winnifred wrote:
Does anyone have any personal theorys on what exactly the dark matter
of the universe is?



My personal theory is that dark matter & energy is stuff that has gone
thru a black hole and come out the other side; from (x,y,z,t) to
(a,b,c,d). It is a Big Bang in an 'alternate' universe.

--
Free men own guns, slaves don't
www.geocities.com/CapitolHill/5357/


  #8  
Old June 19th 06, 11:11 PM posted to sci.space.science
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Default Dark Matter

Astronomers measure all forms of light, not just visible, dark matter
is only dark if it doesn't emit any kind of electromagnetic radiation
(light). It does seem, however, to emit gravitational waves, although
we cannot directly detect these yet, we are working on it. That could
help us alot to further understanding the black hole phenomina.

wrote:
Maybe Dark Matter or Dark Energy isnt really dark at all. like the
picture that is too close for our eyes to distiguish color-maybe the
darkness we see is something our eye's/brains are not equiped to
process.
Nick Hull wrote:
In article . com,
"Tuvas" wrote:

I'm just an undergrad EE major, but with some serious interest in
space. As to what Dark matter is, well, in my mind, the far more
interesting question is, what is dark energy. Dark matter is likely
just stuff in the form of small black holes, sub atomic particles, etc,
which massively adds up. Dark energy, well, that's just wierd,
something's emitting energy that we can't directly see, but affects the
gravitational pull of the uniververse... THAT'S something!

Winnifred wrote:
Does anyone have any personal theorys on what exactly the dark matter
of the universe is?


My personal theory is that dark matter & energy is stuff that has gone
thru a black hole and come out the other side; from (x,y,z,t) to
(a,b,c,d). It is a Big Bang in an 'alternate' universe.

--
Free men own guns, slaves don't
www.geocities.com/CapitolHill/5357/

  #9  
Old June 28th 08, 02:21 PM
hijk129 hijk129 is offline
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  #10  
Old September 8th 08, 08:36 PM
yuqingeng2007 yuqingeng2007 is offline
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Cool adult joke30

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