Nothing? A little bit of it is under every carpet!
0 = A symbol for what is not there, an emptiness that increases any number it's added to, an inexhaustible and indispensable paradox.

Since its foundation, Dia (as typical American invention) has mistaken Art with Investment, Inspiration with Fantasy, and meaning of a work of art with snobism. Behold one more time Americans commanding to hold a smiling mask of pure gold over the sad face of reality...