In 1874, mathematician Georg Cantor was "the first to provide a rigorous proof that there was more than one kind of infinity. Previously, all infinite collections had been implicitly assumed to be equinumerous (that is, of "the same size" or having the same number of elements)." -Wikipedia

Cantor proved that some infinities are larger than others, meaning that infinities can be nested inside one another. Inverting this, one can imagine the possibility of zeros being smaller, and therefore inhabiting, other zeros: NESTED VOIDS.