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Extraordinary claims require extraordinary proof

BeAChooser said:
I think you have the facts about your favorite theory wrong in light of this recent extraordinary claim by a mainstream astrophysicist:

http://www.space.com/scienceastronomy/050223_dark_galaxy.html "First Invisible Galaxy Discovered in Cosmology Breakthrough, 23 February 2005 ... snip ... The ratio of dark matter to regular matter is at least 500-to-1, which is higher than I would expect in an ordinary galaxy," Minchin said." Hard to believe an invisible dark galaxy would have a 500 to 1 ratio if an ordinary Milky Way like galaxy has a 400 to 1 ratio.

Plus, there are mainstream articles like these"

http://www.sciencemag.org/cgi/content/summary/302/5652/1902 "Most galaxies are enveloped in huge dark halos that contain 10 to 20 times as much mass as the luminous stars and cold gas in the galaxies."

http://www-thphys.physics.ox.ac.uk/users/Astrophysics/guides/galaxies/dkmatter.shtml " Within galaxies the amount of dark matter appears to exceed the amount of visible matter by a factor of 10 to 1 in some cases, and even more than this for a few galaxies."

And say, RC ... would an invisible galaxy consist of dark energy stars and dark matter black holes? :D
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Yes it could. :D
 
robinson said:
It is also sad that nobody pointed out the glaring error in that statement, which is so wrong it makes me wonder. Is it that everybody else is dumb, or do people just not read your postings?
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Nah ... I just didn't discover this thread till this afternoon.

And rats! I thought I was the first to catch the mistake.

:D
 
BeAChooser said:
No, RC, wrong again.

The outer regions of galaxies rotate FASTER than can be accounted for by the gravity from visible matter alone. (Assuming MOG isn't correct.) :D
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You are riight - I mis-read the diagram in the Wikipedia article as I stated in my reply to that post.
 
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GreyICE said:
I'm just going to say its very useful that dark matter chooses to behave nothing like regular matter, and stubbornly refuses to hang out near suns.
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Did you miss the latest?

Some mainstream scientists now think DM liked to hang out in stars in the early universe.

http://www.physorg.com/news122034732.html "First stars might have been powered by dark matter"

But then the neighborhood went downhill so it moved to the suburbs.

:D
 
robinson said:
Nope. But nice try.
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This is, of course, because Robinson holds advanced degrees in both astrophysics AND general relativity...

... oh wait, that's right. He doesn't. Nor does he have any damn clue what he's talking about. He just likes to call himself a "skeptic" because apparently he believes that to do good science you must always go against the consensus views of the mainstream scientific community - the Galileo martyr complex, I suppose.

PS: Robinson is also the guy who thinks that vaccines don't really prevent disease and that mercury fillings cause all manner of health problems - just check any of the more recent autism/vaccination threads to see. I also forgot to mention that I've caught him blatantly lying on other threads, so I'd expect to see the same behavior here.

And Robinson, if you try to deny the whole lying bit, I'll dig out the old posts and show everyone. So don't screw around trying to deny it.

EDIT: To hell with it, I'm tired of Robinson's garbage. Here are the posts wherein he was caught blatantly lying, in case you care...

ABC show prepetuates autism/vaccine link - post #218

ABC show prepetuates autism/vaccine link - post #214

ABC show prepetuates autism/vaccine link - post #195

Sigh... now I feel better about venting my spleen. :)
 
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BeAChooser said:
Did you miss the latest?
Some mainstream scientists now think DM liked to hang out in stars in the early universe.
http://www.physorg.com/news122034732.html "First stars might have been powered by dark matter"
But then the neighborhood went downhill so it moved to the suburbs.
:D
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Interesting ... you claim to be a plasma cosmos/electric universe advocate which claim no Big Bang but quote results that are Big Bang specific. :)
 
Reality Check said:
Interesting ... you claim to be a plasma cosmos/electric universe advocate which claim no Big Bang but quote results that are Big Bang specific. :)
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Can't you detect the sarcasm in my post, RC?

I note such things because I love to laugh at each new gnome the BB proponents dream up.

Dark stars and dark galaxies indeed. :rolleyes:
 
I give up. I'm an engineer. I build things. I make reliable structures that just keep working.

This entire debate sounds like a whole bunch of theory and woo to me. Dark Matter? Dark Energy? Forces that act opposite to gravity? Dark matter moving at c? Dark matter moving slowly?

What sort of homeopathic remedy do you give your dark matter if it has too many thetans?
 
GreyICE said:
What sort of homeopathic remedy do you give your dark matter if it has too many thetans?
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Look - how do you know there's such a thing as wind? It's invisible, right?

You measure its effects on pieces of cloth, you have a theory for what it's made out of, you measure its temperature with thermometers, you measure the pressure of the air and various places and correlate wind speed and direction with that, you watch it pick up dust. But you never once see it itself with your eyes.

There are about five independet types of measurements, each consisting of thousands and thousands of observations, which make no sense whatsoever without DM, and make perfect sense with it - and they all agree on how much there is, and at least roughly on its crude characteristics. Furthermore it has been directly observed via strong gravitational lensing (a bit like the mirage you see from air above asphalt on a hot day, go back to that analogy). And lastly, we already know several particles which have nearly all the required characteristics and are almost impossible to detect on earth. Oh, and we havent a clue how else to explain all that data if DM doesn't exist.

Don't you think it's a bit much to expect that in 2008 we should know precisely what all the matter is in the universe, and it's all baryonic? We certainly didn't in 1998, or 1988, or 1958, and there have been many surprises along the way.
 
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GreyICE said:
I give up. I'm an engineer. I build things. I make reliable structures that just keep working.

This entire debate sounds like a whole bunch of theory and woo to me. Dark Matter? Dark Energy? Forces that act opposite to gravity? Dark matter moving at c? Dark matter moving slowly?

What sort of homeopathic remedy do you give your dark matter if it has too many thetans?
Click to expand...

Dark Matter is really a simple matter of observations.
We know the dominant force over long distances in the universe is gravity. The only other candidate is electromagnetism but that balances out over long distances because matter (even plasma) on the large scale has no overall charge. It is fairly simple to calculate the dynamics of a spiral galaxy and find out how the velocity of rotation should vary as you move out from the center. We can look at galaxies and measure this velocity curve. We expect to see the velocity tail off at the edge of the galaxy. But we see the that velocity curve is flat. This implies that there is matter at the edge of the galaxy keeping the velocity up. We cannot see it so we call it "dark matter"
There is a similar observation about the velocity curves in elliptical galaxies and the orbital velocities of galaxies within galactic clusters.

The most important observation is the gravitation lensing caused by unseen matter in the Bullet Cluster. Usually we cannot directly tell the difference between dark matter and the rest of a galaxy or galactic cluster. The Bullet Cluster consists of 2 colliding clusters where the majority of the visible mass is in hot gas (plasma). This produces X-rays that we have detected and mapped. Gravitation lensing is the bending of light caused by mass. We have used this to detect and map the mass in the Bullet Cluster. But the lensing is strongest in 2 regions away from the hot gas - that is the dark matter. The separation of the hot gas and dark matter is because dark matter does not interact strongly with normal matter.

Remember that "Dark Matter" is just a label for whatever this stuff is. There are several theories and these can get strange :) .

Dark Energy is something I don't understand well myself. There is a simple enough observation for it - the universe seems to be expanding at a faster rate according to recent observations. The possibilities for dark energy range from the common place (the cosmological constant in General Relativity) to more exotic theories.
 
Reality Check said:
Dark Matter is really a simple matter of observations.
We know the dominant force over long distances in the universe is gravity. The only other candidate is electromagnetism but that balances out over long distances because matter (even plasma) on the large scale has no overall charge. It is fairly simple to calculate the dynamics of a spiral galaxy and find out how the velocity of rotation should vary as you move out from the center. We can look at galaxies and measure this velocity curve. We expect to see the velocity tail off at the edge of the galaxy. But we see the that velocity curve is flat. This implies that there is matter at the edge of the galaxy keeping the velocity up. We cannot see it so we call it "dark matter"
There is a similar observation about the velocity curves in elliptical galaxies and the orbital velocities of galaxies within galactic clusters.

The most important observation is the gravitation lensing caused by unseen matter in the Bullet Cluster. Usually we cannot directly tell the difference between dark matter and the rest of a galaxy or galactic cluster. The Bullet Cluster consists of 2 colliding clusters where the majority of the visible mass is in hot gas (plasma). This produces X-rays that we have detected and mapped. Gravitation lensing is the bending of light caused by mass. We have used this to detect and map the mass in the Bullet Cluster. But the lensing is strongest in 2 regions away from the hot gas - that is the dark matter. The separation of the hot gas and dark matter is because dark matter does not interact strongly with normal matter.

Remember that "Dark Matter" is just a label for whatever this stuff is. There are several theories and these can get strange :) .

Dark Energy is something I don't understand well myself. There is a simple enough observation for it - the universe seems to be expanding at a faster rate according to recent observations. The possibilities for dark energy range from the common place (the cosmological constant in General Relativity) to more exotic theories.
Click to expand...
See, that works for me. "We dunno what's going on, but we can measure number A, we can measure number B, and the two aren't equal, so we have an unpredicted variable" works just fine (in fact our company frequently gets tens of thousands of dollars for situations that sound pretty much like that). Its when people state with absolute certainty that it can phase through normal matter or is undetectable or doesn't behave like matter should that I have a problem. Usually its a matter of banging up ceiling tiles and looking in back rooms until you figure out where it all went missing (to use an analogy).
 
ynot said:
The E=mc2 post was mainly a joke. But along with the joke there was a point. If you don’t get the joke you probably won’t get the point.

Expanded = Increase in area, bulk or volume. Enlarge, spread out or extended.
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Sigh.It happens.
First I thought about joke,but given I saw enough strange "ideas" I could not be too sure.But haste,you know...
(And I think I already saw something like this!)
 
GreyICE said:
Usually its a matter of banging up ceiling tiles and looking in back rooms until you figure out where it all went missing (to use an analogy).
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So true. There are a few scientist who keep doing science and stuff, and they keep coming up with reasonable reasons for the Galaxy rotation issue.

General relativistic velocity: the alternative to dark matter
F. I. Cooperstockand S. Tieu†,
Department of Physics and Astronomy University of Victoria
January 22, 2008
http://xxx.lanl.gov/PS_cache/arxiv/pdf/0712/0712.0019v1.pdf

Lots of maths, responses to critics of earlier paper, all kinds of scientific stuff. It does not involve magnetism to explain rotation.


Significant reduction of galactic dark matter by general relativity
H. Balasin1, ∗ and D. Grumiller2, †
Institut fur Theoretische Physik, Universit¨at Leipzig, Augustusplatz 10-11, D-04109 Leipzig, Germany
(Dated: March 16, 2008)
http://lanl.arxiv.org/PS_cache/astro-ph/pdf/0602/0602519v2.pdf

It is interesting, because the whole dark matter starts with using Kepler's equations applied to Galaxies. Using GR, the rotation can be explained. Maybe. I wonder why they thought a Galaxy with 200 billion stars would rotate the same as our solar system.

Matter, energy, rotating plasmas, what a huge subject.
 
sol invictus said:
Oh, and we haven't a clue how else to explain all that data if DM doesn't exist.
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That just isn't true.

Modified Gravity: Cosmology without dark matter or Einstein’s cosmological constant
J. W. Moffat1,2 and V. T. Toth1
1Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
2Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
http://arxiv.org/PS_cache/arxiv/pdf/0710/0710.0364v4.pdf

Our calculations relied on analytical approximations.
This is dictated by necessity, not preference; we recognize
that numerical methods, including high-accuracy solutions
of coupled systems of differential equations, as in
CMBFAST (Seljak & Zaldarriaga 1996), or N-body simulations,
can provide superior results, and may indeed help
either to confirm or to falsify the results presented here.
Nevertheless, our present work demonstrates that at the
very least, MOG provides a worthy alternative to ACDMM
cosmology.
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REFERENCES
Adelberger E. G., Heckel B. R., Nelson A. E., 2003, Annual
Review of Nuclear and Particle Science, 53, 77
Brownstein J. R., Moffat J. W., 2006a, Mon. Not. R.
Astron. Soc., 367, 527
Brownstein J. R., Moffat J. W., 2006b, Astrophys. J.,
636, 721
Brownstein J. R., Moffat J. W., 2007, Mon. Not. R. Astron.
Soc., 382 (1), 29
Cole S., Percival W. J., Peacock J. A., Norberg P. et al.,
2005, Mon. Not. R. Astron. Soc., 362, 505
Eisenstein D. J., Hu W., 1998, Astrophys. J., 496, 605
Fischbach E., Talmadge C., 1998, The Search for Non-
Newtonian Gravity. Springer, AIP Press
Hoyle F., Baugh C. M., Shanks T., Ratcliffe A., 1999,
Mon. Not. R. Astron. Soc., 309, 659
Jones W. C., Ade P. A. R., Bock J. J., Bond J. R. et al.,
2006, Astrophys. J., 647, 823
Moffat J. W., 1995, Physics Letters B, 355, 447
Moffat J. W., 2005, Journal of Cosmology and Astroparticle
Physics, 2005, 003
Moffat J. W., 2006, Journal of Cosmology and Astroparticle
Physics, 2006, 004
Moffat J.W., 2007, To be published in Int. J. Mod. Phys.
Moffat J. W., Toth V. T., 2007a, ArXiv, 0712.1796 [grqc]
Moffat J. W., Toth V. T., 2007b, ArXiv, 0708.1935
[astro-ph]
Moffat J. W., Toth V. T., 2007c, ArXiv, 0708.1264
[astro-ph]
Mukhanov V., 2005, Physical Foundations of Cosmology.
Cambridge University Press
Padmanabhan T., 1993, Structure formation in the universe.
Cambridge University Press
Park C., Vogeley M. S., Geller M. J., Huchra J. P., 1994,
Astrophys. J., 431, 569
Riess A. G., Strolger L.-G., Tonry J., Casertano S. et al.,
2004, Astrophys. J., 607, 665
Seljak U., Zaldarriaga M., 1996, Astrophys. J., 469, 437
Spergel D. N., Bean R., Dor´e O., Nolta M. R. et al.,
2007, Astrophys. J. Suppl., 170, 377
Tegmark M., Blanton M. R., Strauss M. A. et al., 2004,
Astrophys. J., 606, 702
Tegmark M., Eisenstein D. J., Strauss M. A. et al., 2006,
Phys. Rev. D, 74, 123507
Weinberg S., 1972, Gravitation and Cosmology. John
Wiley & Sons
 
I have no idea if those scientist are correct or not, I am pointing out the obvious evidence that dark matter and dark energy are by no means "proved", or accepted by everyone as proved.
 
robinson said:
I have no idea if those scientist are correct or not, I am pointing out the obvious evidence that dark matter and dark energy are by no means "proved", or accepted by everyone as proved.
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No, not everyone. John Moffat still doesn't agree.

Let me point out how many of the references in that paper are papers by Moffat. That's a VERY bad sign - percentage of self-cites is one of the first things to look at when you don't know a field and you want to know if someone's a crackpot. (In this case I know the field and I know Moffat, as well as nearly everyone else on that list, and I know he's a crackpot.)

I glanced through the papers that aren't by him, and at least most are by people that certainly do not believe in MOND (Moffat refs them because he's using their results, not because they agree with him).
 
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Hmm

robinson said:
General relativistic velocity: the alternative to dark matter
F. I. Cooperstockand S. Tieu†,
Department of Physics and Astronomy University of Victoria
January 22, 2008
http://xxx.lanl.gov/PS_cache/arxiv/pdf/0712/0712.0019v1.pdf

Lots of maths, responses to critics of earlier paper, all kinds of scientific stuff. It does not involve magnetism to explain rotation.


Significant reduction of galactic dark matter by general relativity
H. Balasin1, ∗ and D. Grumiller2, †
Institut fur Theoretische Physik, Universit¨at Leipzig, Augustusplatz 10-11, D-04109 Leipzig, Germany
(Dated: March 16, 2008)
http://lanl.arxiv.org/PS_cache/astro-ph/pdf/0602/0602519v2.pdf
Click to expand...
 
robinson said:
Hmm
Click to expand...

Do you expect anyone to talk to you when you ignore most of the responses you get?

That first paper is a version of an earlier paper by the same authors that was totally wrong, as you've been told (and given several references). The second also seems to be claiming GR corrections are important for rotation curves, which is also wrong (and it's very easy to see why - I'll show you if you ask nicely).
 
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