What is the evidence of 'Black Force' in this universe?

Answer 1

I think you are referring to "dark matter." Dark matter is matter that does not emit or reflect radiation so it cannot be visibly detected. The evidence of its existance comes from its gravitational effects on matter that we can see.
You can read about different methods devised to detect it and its history here:
http://en.wikipedia.org/wiki/Dark_matter

Answer 2

Dark matter (energy) has not been observed until just recently. A Stanford grad was able to observe two galaxies colliding and there is visible evidence of dark matter surrounding the two galaxies in that their collisions caused the dark matter to become visible. [See source.]

Dark matter/energy is important because gravitational indications show that only about 4 % of the universe can be seen. The rest of it, accounting for most of the gravity, has to come from something that cannot be seen: the dark matter.

Answer 3

Dark matter, if this is what you are referring to, is matter that cannot be detected directly as it does not give out or reflect any or enough radiation.

For more info check out: http://en.wikipedia.org/wiki/Dark_matter

Answer 4

to every action there is an equal opposite reaction