Perhaps all that has been done so far is an exercise in formalism. Even if 0 is an ubiquitous principle, and everything that subsists expresses the fact 0 universally obtains, the condition doesn't, it may be argued, explain the colours, sounds, tastes, smells, pains, occurrent thought-episodes and our personal experiential manifolds in all their manifest diversity. Surely 0 can't do all the work, here at least? Wouldn't abracadabra be just as good a placeholder as zero?
A Monist Amok
"I believe there is no philosophical high-road in science, with epistemological signposts. No, we are in a jungle and find our way by trial and error, building our road behind us as we proceed."
As far as I know, nobody has any explanation of why phenomenal, say, green is green rather than any other colour or experience, or why it should exist given the supposed causal sufficiency of physical law. So the ideas that follow really do pile speculation on speculation. Yet they are radically conservative insofar as they don't involve modifying the formal structure of our core theory of the physical world, quantum mechanics. Nor do they involve adding extra parameters.
Presently, we have to grapple conceptually with (at least) three disparate categorical super-kingdoms, so to speak. Each has independently powerful claims to ontological legitimacy:
So how do the elements of the trinity fit together: the "phenomenological" world, the "physical" world, and the "mathematical" world? On the unargued assumption that the principle underlying ultimate reality is radically simple, it will here be conjectured that these three realms are one-and-the-same under different descriptions. Each realm supports its own variant of the zero ontology: this isn't a co-incidence. If and when each realm is fully understood by our descendants, their constituents will be found each to cancel out, or to be derivable from fundamental properties that do cancel out. Canonically construed, they are strictly equivalent to 0. Physics = mathematics = phenomenology = 0. The equations of mathematical physics describe an all-pervasive field etc-theoretic what-it's-like-ness that is what it takes for 0 to be the case.
- the "phenomenological" (consciousness in its wildly different textures - from the mistily ethereal to savagely and painfully concrete; and from the merest punctate twinkle to the (QM-coherently?) richly composite states of human minds)
- the "physical" (the knotty/foamy/stringy/membrany/field etc-theoretic ontology of fundamental natural science, likewise with their wildly different values). [Direct (or "folk") realists about perception would also include in this physical (rather than the phenomenological) category the notional classical macroscopic objects to which their "awake" consciousness kindly grants them access. Folk-realism, awkwardly, is inconsistent with the experimental, neuro-philosophical and quantum mechanical evidence].
- the "mathematical", where, at the very least, a sort of as-if platonism rules; the unreasonable effectiveness of mathematics in describing and predicting phenomena in the empirical world is matched by [and might ordinarily be claimed to exceed the world's finite(?) stock of] a notationally daunting superabundance of different values too.
A further equivalence can be noted. The zero ontology can also be expressed in idiom of information theory - though the ontological status of "information" is obscure. One counterintuitive prediction of the zero ontology is that the total information content of the multiverse is precisely zero. From a notional god's-eye perspective, there is no net information. This claim seems manifestly false, not to mention absurd: surely the information content of the world is huge, limited perhaps only by the Bekenstein bound - the hypothetical upper bound on the amount of information inside a spherical region with a given energy. Even if the algorithmic information content of the multiverse as a whole is small, perhaps even close to zero [as proposed by Max Tegamark], it isn't exactly zero, as predicted by the zero ontology; so the zero ontology must be false. Yet this dismissal is at best premature. If all possible string vacua, space-time geometries, masses of elementary particles and interaction strengths, and (by)laws of physics are realized, then all possible descriptions are satisfied. This is equivalent to zero information. Such an equivalence is counterintuitive: it violates one's naïve intuition that, say, a dimensionless point, or a timeless void ["Nothing"] express less information than the multiverse. Intuition aside, traditional interpretations of quantum mechanics in which wave functions really collapse are inconsistent with the zero information conjecture: picturesquely, if one sees a live cat, then one's doppelganger sees a dead cat - otherwise, the conjecture is false. But if zero information is indeed the default-condition from which any supposed departure must be explained, then the equivalent co-existence of all self-consistent alternative possibilities - the multiverse - inherits such default status. On this analysis, the multiverse is the physical expression of what a total absence of information logically entails. The mathematical formalism of quantum mechanics describes how all co-existing possibilities interfere. The formalism describes the environment-induced decoherence of such quantum superpositions into (what masquerade as) information-rich quasi-classical worlds. But total information content remains zero.