Banach-Tarski says that given a glass ball, we can break it into two glass balls of equal volume to the original (plus other generalizations). The explanations I have found for this paradoxical notion is that volume is *not* an invariant when we do these operations.

But, surely volume should be an invariant, right? "In reality," is it not realistic to expect that the volume doesn't change (unless we are dealing with some *chemical* property here, which I assume not since it is a *mathematical* paradox)?

So, my question is: is it possible, given whatever machinery we want to invent (something to break the glass exactly into what shape pieces we want, etc.), to actually perform this "paradox?" If not, then what is the "trick" behind the paradox which makes the math work out? What abstraction from reality do the hypotheses assume?

N.B. I've done extensive googling (especially on this site) of the subject and none of the answers have satisfied my question. I do realize there are a lot of questions about Banach-Tarski on this website already, but I do believe that my question is not a "duplicate."