—–

I rather like quarkark – I think you’re on to something.

Since dark matter interacts gravitationally with standard matter, dark matter black holes capture normal matter, so they should be visible.

If you are inventing particles and forces you can make them fit any data you want.

Stay tuned; that dark sector may turn out to be a pretty exciting place after all.

I see what you did there.

What sorta observations will help you decide one way or another? Can it be done with any of the gizmos up there now (I really want for something to find a good use of Kepler)? And if not what thingummajig do you most want to see built/launched? (The Astronomy Cast kindly informed that the Ares V rocket is gonna be an unparallelled workhouse (assuming they actually build the damn thing). Apparently it could launch the Gemini Observatory, as is, to make our biggest (and most useless) spacebased observatory yet.)

Dark Matter does clump up into a cob-web structure. (You may have seen pictures) But it does not clump the same way ordinary matter does. This was my point, adding charges and atoms, and etc seems like dark matter is becoming like another copy or ordinary matter which is ruled out.

But, Sean says these details have been worked out in these papers so I need to read them before I say much more.

I would love to think dark matter has all these properties, it just seems like the data fits best if you assume it doesn’t. (So it seems to me. But I admit I need to read the papers.)

I thought the idea was that dark matter *does* clump into dark galaxies, overlapping with visible matter galaxies, to account for the otherwise anomalous rotation rates of stars in the latter.

Also, given their elusive nature and apparent reluctance to “clump up”, or interact at all with normal matter, is it easy to exclude tachyons of some kind as candidates for dark matter? After all, strictly speaking, relativity only prohibits travel *at* the speed of light doesn’t it?

Mind you, I suppose that might be ruled out by the Bullet galaxy, where a collision has apparently separated the visible matter from the dark matter – If the latter comprised tachyons then presumably, attracted by gravity to sluggish visible matter, it would have no trouble keeping up, like a cloud of flies buzzing round an ambling cow.

Obviously we know enough about dark-matter dynamics to say that it’s not simply a copy of ordinary matter. But if you’re inventing new particles and forces, you have various parameters to play with, including the masses and the strengths of the interaction. There is a limit in which the particles become very heavy and/or the forces become very weak, and in that limit you just recover ordinary non-interacting dark matter. The question is, where exactly is the dividing line between allowed and ruled out?

So there are scenarios to test your model, and they aren’t even all that complicated. They just aren’t cosmological ones.