Quote Originally Posted by ?????
Dark matter has a negative gravity force associated with it; it actually repels matter instead of attracting it. It is one of many postulated reasons why the universe's expansion appears to be accelerating.
= physics... commonly referred to as anti-matter. to make it simple; it is the opposite of matter. Scientist are unable to isolate anti-matter, as contact between anti-matter = big explosion + gamma ray = death.

Quote Originally Posted by ?????
In fiction, it's often imbued with powerful magical properties; Dark Matter is required to learn some of the strongest spells in several games. As for teaching magic, it works based on the postulates of whatever metaphysical system is present in the literature.
Dark Matter = fictional anti-magical matter. therefore magical matter + anti-magical matter = big explosion + magical "radiation" = death...

I think that sums it up...