Scientist think they have photographic proof of dark matter from this picture of some blurry clouds. Dark matter is what scientists believe most of the universe is made of. Dark matter is neither matter nor anti-mater. It is just heavy theoretical goo that does not reflect or emit light. It is not made up of atoms or particles, or maybe it is. No one knows.
Want to know something else? They also think there is dark energy. And dark energy accounts for even more of what exists in the universe. And they think, but are not sure that dark energy interacts with dark matter.
If there is as much of this bloody stuff as they say, why is it so hard to find? If religious nuts spent as much time poking holes in science as happens with the reverse, no one would buy any of this crap. Are you aware that we still don't have a decent explanation of why gravity occurs? It is not energy, it is a force. It bends the space/time continuum. That is the best they have for why things fall down.
Gravity is also why you need dark matter and dark energy to make current models of the universe work. There is a good chance that within our lifetimes classic physics, astrophysics, and quantum mechanics will all have to be revised. Why? Because there are almost as many contradictions going on as in the Bible.
Don't get me wrong. I love science. I just think most people blindly accept it as truth. It is just what we have at the moment that seems to work. The very computer on which I type is proof of of how useful science can be. (Well maybe not this crap-tastic piece of crappity crap, but computers in general.)
Just sometimes the scientific rationale is just as irrational as anything else. Why not just attribute the missing mass to the infinite stack of turtles supporting the Earth? Then you're finished. Right there. Universe explained. Move on to other problems.