"Make an assumption, knowledge in the future changes. How can this be refuted?"
Well I'm not assuming that knowledge in the future changes. But I'm saying you can't prove that it won't.
So all I'm really doing is pointing you to the limitations of our knowledge. If our only "real" knowledge is through induction, and induction has limitations, then our knowledge has limitations. So, yeah, I guess if you wanted to "refute" this, you would have to show how we could have absolute certainty. But that burden is on you of course since you're the one claiming this.
Well I don't care if it's convenient or not, I just care if it makes sense.
Do you actually disagree with what I said or does it just make you mad?
If the body of knowledge stays the same, there is no possibility of an elephant flying.
If it doesn't stay the same, then there is (though it would be minute).
"Lame" or not, I just care whether it's correct. Really it's not lame, though, because it actually clarifies the nature of the disagreement if anything. It shows that I don't disagree with you on the current state of facts, and my disagreement more stems from the limitations of human knowledge.