[Ced (OP)]

Is there a possibility that dark matter is nothing? While most cosmologists think that dark matter can pass through anything and leave no noticeable trace that just doesn't seem like it could exist in out "known" universe. The way I think of this is everything is naturally apposed to nothing, like trying to push the plus sides of to magnets together, it just doesn't work and they naturally break away from each other. I'm sure that this possibility has been mentioned before but I could not find a post or publishing of this.

[JP]

. . . everything is naturally apposed to nothing, like trying to push the plus sides of to magnets together . . .

I'm not sure what you mean by everything repelling nothing, since those are concepts, not actual objects.  But in order to repel each other, objects have to interact with each other via forces.  The thing about dark matter is that it only interacts with other matter through gravity, which is a very weak force compared to the others we know about, and which is only attractive.  Therefore dark matter attracts other matter and is attracted to it.

On the point examples of dark matter-like behavior, neutrinos are a particle that we know of that behaves very much like dark matter.  They're invisible to most detectors and it is extremely rare that they interact with other matter, they're so "dark" that trillions are passing through you every second without you noticing.

[Pmb]

Is there a possibility that dark matter is nothing?

Sure. Its possible that the laws of gravity, as we currently understand them, are wrong. I don't believe that is the case myself.

While most cosmologists think that dark matter can pass through anything and leave no noticeable trace that just doesn't seem like it could exist in out "known" universe. The way I think of this is everything is naturally apposed to nothing, like trying to push the plus sides of to magnets together, it just doesn't work and they naturally break away from each other. I'm sure that this possibility has been mentioned before but I could not find a post or publishing of this.

The reason that the same poles of magnets oppose one another is because they interact via the electromagnetic force. Two charged particles interact by the same force. This is because particles which make these up are charged. Dark matter is thought to be uncharged and that implies that it is dark. This also is why dark matter can pass through matter, i.e. because it doesn't interact with the charged particles which make up matter.

[reasonmclucus]

Dark matter is a bad term. It's based on human psychology not physics.  We tend to think of something we don't understand as being dark. What they mean is something that cannot be easily seen.  What is really meant is invisible matter which could be dark or simply transparent.  An aether with mass could provide the mass that "dark matter" is expected to provide. 

Transparent substances can sometimes be detected by slight changes in the light passing through it.  The red shift that is sometimes suggested as indicated the relative speed of distant objects, could instead be evidence of transparent matter particularly considering that the shift tends to depend on distance.  Hubble images indicate that some distant galaxies are moving toward each other which means some distant objects should be moving toward earth instead of all moving away.