Coloradomtnman
Rational and proud of it.
It depends on what you mean by "observe". Dark matter, by definition cannot be "seen", however they have observed gravitational lensing caused by the motion of dark matter through a region of space. Gravitational lensing will only occur when there is some mass present, bending light. The fact that they observed the lensing effect without actually being able to see the mass is strong evidence for the reality of dark matter.
Not to mention the observbed drag on the outer regions of spinning galaxies which demonstrates a gravitational tug by unseen matter.
I don't think JohnSt.Onge (is that right?) is knowledgeable in the field of physics, astronomical or quantum. Its obvious he doesn't understand the uncertainty principle or that, so far as modern science can understand, that reality is based on probabilities. And I think he finds, as many religious people do, that uncertainty and the nonexistance of absolutes uncomfortable.