http://en.wikipedia.org/wiki/Dark_matter


quote "dark matter is matter that does not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence may be inferred from its gravitational effects on visible matter. "

that means it looks like nothing is there but it really actually is.u think nothing is there but the particles on the dark matter are sooooo small it dont emit or have radiation...

so it means to some people

dark matter = nothing

nothing being something u dont know is there