Dark matter skeptical question #4?

Question

Dark matter has been blamed for the irregular clumping and filamenting of huge numbers of galaxies. I don't see it. If the Universe expanded and then became asymmetrical, the condensing would continue toward centers of gravity, and not necessarily uniformly on a cosmic scale. If dark matter was 95% of the mass of the Universe, then this would explain NON-clumping and the *absence* of filaments. And if such matter exists and it interacts gravitationally, wouldn't there be gravitational centers where it constitutes the majority of the mass, like in giant stars? Yet we don't see any unexplained mass there. How can this stuff be 95% of the Universe and essentially 0% of stars?

Hmmm, what happened to my 2nd and 3rd questions? I think there is a conspiracy to silence me!!

Richard, do you smell ether in the background? They had luminiferous ether. It was popular. I think this is going to be gravitational ether and will go the same way.

Rellkll...I could be wrong. Admittedly I did not spend a lot of time reading about this. I thought this idea came out at least ten years ago and was being offered as an explanation for why the large scale structure of the galaxies looked uneven and filamentary.

Answer 1

The fact that dark matter clumps to form galaxies but not stars places strict limits on its temperature. Since it does not clump inside of stars, it must be too hot (the particles have escape velocity) to do so. On the other hand, it must be cool enough to clump into galaxies (they don't have escape velocity from galaxies).

It's tempting to classify dark matter amongst the ether theories of crackpot scientists, except for two things. (1) Dark matter solves at least five major, and completely independent astrophysical problems. Ether solved only one physics problem. Not all the problems dark matter solves are gravitational: it solves the CMB anisotropy problem and the Sunyaev-Zeldovich effect in clusters, neither of which are primarily gravitational. (2) It should not be surprising that there is a great deal of matter we cannot see. "Seeing" involves light waves, and there's no reason to think that all particles are compelled to emit and absorb light. In fact, an electrically neutral particle MUST not interact with light. The only reason we see neutrons, ever, is the fact that they are actually composed of charged particles, and we can detect their faint magnetism. In point of fact, we hardly ever directly detect them at all--- and that's a frelling *neutron*. Just because we rely on light waves for survival doesn't mean the rest of the universe has to.

Answer 2

Stars are seen to orbit around the center of their galaxies faster then newton's laws of motion and gravity say they should. So either the laws of physics are wrong (which does not seem likely) or else these galaxies contain much more mass than we can see by counting the stars in them.

So dark matter is simply any mass that is not in a star. It could be planets, gas, dust, black holes, neutrinos, or unknown particles.
We know that mass must be there and there must be alot of it. But we are not sure exactly what it is.

Answer 3

The reason is that Dark Matter interacts primarily by gravity, whereas normal matter interacts via the electromagnetic force as well. This means that if you slam two blobs of normal matter together, you will get a shock front with very high density, and the two blobs will "stick" to some extent. If you slam two blobs of dark matter together, they will pass through each other, possibly pulling out a "tidal tail" of material. So the dynamics of normal matter and dark matter in galaxy and star formation are entirely different.

Answer 4

why are we trying to figure out anything about dark matters role in the universe as a whole?
there is a reason it is dark matter, we know vertualy nothing about it, same for dark energy
shouldn't the focus be on how can we learn what this stuff is, and how can we identify it?
just a thought

Answer 5

"...Dark matter has been blamed for the irregular clumping and filamenting of huge numbers of galaxies..."

Unless I'm badly mistaken (..and it wouldn't be the first time..) inflation is viewed as the primary cause of clumping and filamenting.

Answer 6

Don't look at me. I've considered "dark matter" to be voodoo science ever since I heard of it. It sounds like an epicycle solution to a problem you cannot understand. Just keep adding epicycles until your prediction matches the data. I suppose it's clever math, its just not very good science.

Answer 7

it DOES clump together
http://www.space.com/scienceastronomy/050223_dark_galaxy.html

it DOES have gravity
http://www.youtube.com/watch?v=EJtJ7Q0cV34

http://www.youtube.com/watch?v=gCgTJ6ID6ZA


still waiting for information from CERN considering the "GOD" particle and the quest for explaining "mass"
and still waiting to get a piece of dark matter to analyze