[simne]

You confused PHYSICS definition with ASTRONOMY definition, they are different.

For ASTRONOMY, dark matter is just what they could not see, but have gravitation features. And as I said, for astronomy, ~50% of dark matter is nothing special, but for example, only extreme models could suggest tens of thousands Black holes (to fill 50% of emptiness), because of this, they conclude, that exists something other matter which we don't know.

For PHYSICS, technical meaning of dark matter is special type of matter.

[hollerith]

But the person you replied to was using the physics definition, and you reply as if he used the astronomical definition.

[simne]

We have confusing and extremely sophisticated context. It involving wide spectrum of less complex contexts. Physics and astronomy, depend on from what direction we look on it.

Good that we found understanding on this.