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This seems like another example of what confuses the issue. Joel Send a noteboard - 30/04/2011 05:25:04 PM
The Wikipedia page on MACHOs (MAssive Compact Halo Objects) gives a good summary of the research into non-luminous ordinary matter as a dark matter candidate. It just about universally demonstrates that such objects can only account for a small fraction of all dark matter.

At the bottom of the Wikipedia page is a link to one on RAMBOs, described thus:
In astronomy, a RAMBO or robust association of massive baryonic objects is a dark cluster made of brown dwarfs or white dwarfs.

RAMBOs were proposed by Moore and Silk in 1995. They may have effective radii between 1 and 15 pc, with masses in the range 10–100,000 solar masses.

Dynamics

The dynamics of these objects, if they do exist, must be quite different from that of standard star clusters. With a very narrow mass range (all brown dwarfs or white dwarfs), the evaporation rate of these RAMBOs should be very slow as predicted by the evolution of simulated mono-component cluster models. Theoretically, these very long-lived objects could exist in large numbers. The presence of a clustered thick disk-like component of dark matter in the Galaxy has been suggested by Sanchez-Salcedo (1997, 1999) and Kerins (1997).

So, they're baryonic dark clusters, and the last sentence implies they could account for any dark matter halo around the Milky Way. So now there's yet another new proposal for dark-but-normal matter that could fit the bill without anything more exotic than very distant and/or non-luminous but quite familiar brown and/or white dwarfs.

Meanwhile, I'm not sure how convinced I am by a visual search failing to find extremely faint and distant objects. The theoretical argument is more compelling, but it depends on our current understanding of the Big Bang being correct, and that sems as likely to contain key errors as it is to rule out baryons accounting for all dark matter.

But, yeah, by all means test the theory; you have to, and if it's fully vindicated I'll accept that. Just don't spend so much effort devising more and more tests for a theory that defies proof that you overlook a simpler (and accurate) explanation. ;)
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For completeness, the RAMBO link, though you're probably familiar.
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Exciting video about the universe Camilla - 28/04/2011 10:14:55 AM 1286 Views
Cool, and true *NM* Stephen - 28/04/2011 11:46:29 AM 445 Views
I still think dark matter's just non-luminous matter without a convenient light source to reflect. Joel - 28/04/2011 10:34:21 PM 993 Views
We've just about ruled out the idea that dark matter is just non-luminous "ordinary" matter. Dreaded Anomaly - 28/04/2011 11:44:34 PM 937 Views
I'm aware of the Bullet Cluster, though admittedly not much more than that. Joel - 29/04/2011 01:52:49 AM 874 Views
Re: I'm aware of the Bullet Cluster, though admittedly not much more than that. Dreaded Anomaly - 29/04/2011 02:56:32 AM 966 Views
Re: I'm aware of the Bullet Cluster, though admittedly not much more than that. Joel - 30/04/2011 05:02:49 PM 908 Views
Re: I'm aware of the Bullet Cluster, though admittedly not much more than that. Dreaded Anomaly - 30/04/2011 08:56:35 PM 829 Views
Re: I'm aware of the Bullet Cluster, though admittedly not much more than that. Joel - 02/05/2011 01:28:30 AM 840 Views
Re: I'm aware of the Bullet Cluster, though admittedly not much more than that. Dreaded Anomaly - 04/05/2011 04:18:18 AM 934 Views
There's such a thing as knowing when you're licked, and I believe I am. Joel - 07/05/2011 02:04:53 AM 1014 Views
Re: There's such a thing as knowing when you're licked, and I believe I am. Dreaded Anomaly - 09/05/2011 11:28:48 PM 846 Views
Re: There's such a thing as knowing when you're licked, and I believe I am. Joel - 14/05/2011 05:36:45 AM 809 Views
Re: There's such a thing as knowing when you're licked, and I believe I am. Dreaded Anomaly - 17/05/2011 02:09:40 AM 879 Views
Re: There's such a thing as knowing when you're licked, and I believe I am. Joel - 19/05/2011 04:55:21 AM 812 Views
Re: There's such a thing as knowing when you're licked, and I believe I am. Dreaded Anomaly - 24/05/2011 09:32:27 PM 889 Views
The Pati-Salam model was the one I had in mind. Joel - 24/05/2011 10:34:04 PM 845 Views
Re: The Pati-Salam model was the one I had in mind. Dreaded Anomaly - 24/05/2011 11:08:01 PM 1048 Views
Re: The Pati-Salam model was the one I had in mind. Joel - 25/05/2011 01:27:10 AM 856 Views
Re: The Pati-Salam model was the one I had in mind. Dreaded Anomaly - 31/05/2011 09:16:18 AM 925 Views
Apologies for the delay; internet's been spotty and I've been busy lately. Joel - 10/06/2011 12:09:04 AM 1179 Views
Re: Apologies for the delay; internet's been spotty and I've been busy lately. Dreaded Anomaly - 14/06/2011 03:38:18 AM 1170 Views
Also, re: lensing from ordinary matter: Dreaded Anomaly - 29/04/2011 05:18:47 AM 875 Views
This seems like another example of what confuses the issue. Joel - 30/04/2011 05:25:04 PM 991 Views
Re: This seems like another example of what confuses the issue. Dreaded Anomaly - 30/04/2011 08:56:40 PM 967 Views
That discussion seems to reduce to "as little new and exotic physics as possible". Joel - 02/05/2011 01:29:03 AM 946 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Dreaded Anomaly - 04/05/2011 04:18:24 AM 908 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Joel - 07/05/2011 02:05:02 AM 1079 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Dreaded Anomaly - 09/05/2011 11:29:36 PM 860 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Joel - 14/05/2011 05:35:56 AM 1153 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Dreaded Anomaly - 17/05/2011 02:09:55 AM 758 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Joel - 19/05/2011 02:47:25 AM 1112 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Dreaded Anomaly - 24/05/2011 09:46:30 PM 882 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Joel - 25/05/2011 12:20:10 AM 1181 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Dreaded Anomaly - 31/05/2011 09:16:22 AM 988 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Joel - 10/06/2011 12:04:06 AM 1229 Views
Re: That discussion seems to reduce to "as little new and exotic physics as possible". Dreaded Anomaly - 14/06/2011 03:38:12 AM 993 Views
Re: I still think... (apparently, there is a 100 character limit on subjects, and yours was 99) Tor - 28/04/2011 11:57:15 PM 1320 Views
Seems to happen to me a lot; sorry. Joel - 29/04/2011 12:56:14 AM 858 Views
None of this reflects on the actual facts of dark matter. Dreaded Anomaly - 29/04/2011 01:32:52 AM 857 Views
I concede my grasp (or grope) is a somewhat superficial laymans, yes. Joel - 30/04/2011 04:30:28 PM 992 Views
Re: I concede my grasp (or grope) is a somewhat superficial laymans, yes. Dreaded Anomaly - 30/04/2011 08:56:44 PM 803 Views
Re: I concede my grasp (or grope) is a somewhat superficial laymans, yes. Joel - 02/05/2011 01:28:58 AM 1331 Views
Re: I concede my grasp (or grope) is a somewhat superficial laymans, yes. Dreaded Anomaly - 04/05/2011 04:18:27 AM 835 Views
I don't object to changing my mind, but can take more convincing than I really should. Joel - 07/05/2011 02:05:09 AM 1051 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Dreaded Anomaly - 09/05/2011 11:32:17 PM 959 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Joel - 14/05/2011 05:36:24 AM 1153 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Dreaded Anomaly - 17/05/2011 02:10:03 AM 876 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Joel - 19/05/2011 04:33:06 AM 1134 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Dreaded Anomaly - 24/05/2011 09:59:38 PM 869 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Joel - 24/05/2011 11:19:43 PM 836 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Dreaded Anomaly - 24/05/2011 11:33:58 PM 782 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Joel - 25/05/2011 12:55:36 AM 889 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Dreaded Anomaly - 31/05/2011 09:16:24 AM 835 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Joel - 10/06/2011 12:09:13 AM 1014 Views
Re: I don't object to changing my mind, but can take more convincing than I really should. Dreaded Anomaly - 14/06/2011 03:38:05 AM 976 Views
Might help if you clarified where your skepticism is at Isaac - 29/04/2011 02:32:07 AM 823 Views
Potentially either, or a combination of the two. Joel - 30/04/2011 02:36:50 PM 910 Views
It's hard to discuss without knowing your objections a bit more clearly Isaac - 30/04/2011 04:58:03 PM 799 Views
My primary objection is that alternatives to dark matter seem to have been ruled out prematurely. Joel - 02/05/2011 01:29:14 AM 1006 Views
Well, they weren't, not really sure how else to put that Isaac - 10/05/2011 03:19:57 AM 999 Views
Alright then, objection withdrawn (cautious skepticism intact). Joel - 14/05/2011 05:34:17 AM 1120 Views
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