
Originally Posted by
DrRocket
Science can easily prove to me that the whole universe is not a construct of your imagination
What Boratssister is refering to there, I would think, is solipsism, only it's worded in a wrong way. Tho obviously I would say that if I was just a figment of his imagination 
The question of what "fact" means in and of itself is an interesting one tho when regarding real world phenomena outside of "definitional truisms" such as mathematics. Since all our observations of reality are to a degree subjective, the best we get is intersubjectivity, not objectivity. To achieve this in such a way that it can be assume the intersubjective world view is as close as possible to what can be assumed to be objectively true ("fact"), science counts repeatability and parsimony among its central criteria. Parsimony is, incidentally, a fairly good but not conclusive counter to solipsism too.
The dog, the dog, he's at it again!