has dark matter been proven?

[gib65]

I remember hearing several years ago that the existence of dark matter wasn't quite known, that scientists weren't yet comfortable talking about it as though it had been proven conclusively. Now-a-days, whenever I hear reputable sources talking about the subject, it's talked about as though it has finally become an established fact.

 

My question: does the scientific community generally regard the existence of dark matter "proven"? If so, was this shift recent? What are some of the examples of evidence that recently came in (or have been in for a while) that encouraged scientist to take the attitude of certainty about dark matter's existence?

[mathematic]

The evidence for dark matter is the fact that if it wasn't there, galaxies and galactic clusters would fly apart. There just isn't enough (by about a factor of 5) to hold these things together.

[timo]

Dark matter is not proven, but there is rather solid evidence. I think today most physicists believe in the existence of dark matter.

Considering the evidence for dark matter you may consider using this talk by Laura Covi as a starting point. The velocity relations of clusters and galaxies (slides 4 and 7) were already mentioned. I'd point out the interesting result on slide 6 which, if I recall that correctly, is a result of a cluster collision that -if only the visible matter which I think is the pink clouds was there- should not happen like this according to classical gravity. But if one adds a component of invisible matter with a low interaction with ordinary matter (blue clouds, but don't take my word for it), the simulations fit what is actually seen. The result on slide 5 I hadn't heard about before, but it seems rather straightforward (except that I don't know which temperature is spoken of and how dark matter comes in there).

[Mystery111]

Dark matter is not proven, but there is rather solid evidence. I think today most physicists believe in the existence of dark matter.

Considering the evidence for dark matter you may consider using this talk by Laura Covi as a starting point. The velocity relations of clusters and galaxies (slides 4 and 7) were already mentioned. I'd point out the interesting result on slide 6 which, if I recall that correctly, is a result of a cluster collision that -if only the visible matter which I think is the pink clouds was there- should not happen like this according to classical gravity. But if one adds a component of invisible matter with a low interaction with ordinary matter (blue clouds, but don't take my word for it), the simulations fit what is actually seen. The result on slide 5 I hadn't heard about before, but it seems rather straightforward (except that I don't know which temperature is spoken of and how dark matter comes in there).

 

Well correct me if I am wrong, but aint Neutrino's a form of dark matter? Technically dark matter does not interact Electromagnetically, and niether do neutrino's.

[timo]

The point of dark matter is that several phenomena that do not match how we expect nature to behave could be explained by assuming some (invisible) additional matter content. The point is not that an elementary particle with no electric or color charge is something so great that we want to give it an extra name. Dark matter must not have an electric charge, but that doesn't make anything with that property dark matter. The addition of neutrinos alone would not suffice to explain the conflicting phenomena. Or in other words: based on having the characteristics attributed to dark matter you can call neutrinos being dark matter without being completely incorrect - but it seems like a pointless statement to me.

Edited October 28, 2011 by timo

[Mystery111]

Yes, I am under the impression our model does not have a sufficient amount of them... mind you, we are more or less awash with these speedy particles all around us. I think trillions of these particles pass my body in under a second.

 

Do you know how much would account for the dark matter phenomenon... I've even read papers recently attributing dark matter to black holes.

[timo]

There has been a variety of conventional objects being proposed as being dark matter, including lonely planets, black holes, neutrinos, neutron stars, ... . Except for the neutrinos they go under the name of Massive Astrophysical Compact Halo Objects (MACHOs). They are mentioned on slide 9 of the talk I linked.

I think they appear too seldom to account for dark matter, but you can just have a look at the paper that is mentioned if you are really interested.

[gib65]

Thanks everyone, that answers my question.

[Mystery111]

There has been a variety of conventional objects being proposed as being dark matter, including lonely planets, black holes, neutrinos, neutron stars, ... . Except for the neutrinos they go under the name of Massive Astrophysical Compact Halo Objects (MACHOs). They are mentioned on slide 9 of the talk I linked.

I think they appear too seldom to account for dark matter, but you can just have a look at the paper that is mentioned if you are really interested.

 

Yes, I am interested. I know a little about the MACHOs definition, so I'd be interested in learning the fringe idea's.

[LightBender]

Dark matter is not true matter. It is all of the infinite points (singularities) that were stretched into negative curvature during inflation (which is still occurring). Some of these points or singularities were energized with enough energy to balance the cosmological constant and became sub atomic particles. This was done via spin. It is that same spin that creates curvature of the second order or gravitational fields. It is the singularities spring like tendency to return to its size prior to the stretch that creates curvature of the first order or dark matter. When this action is compressive or having positive curvature the behavior is like a bow wake or the leading wave front of an explosion. The result is it pushes spaces creating what we call dark energy. Basically dark matter and dark energy are resultant of space and energy deforming space from its zero state. The amount of curvature is governed by the cosmological constant.