  The proper resolution of the so-called measurement problem requires a
"top-down" conception of the quantum world that is opposed to the usual
"bottom-up" conception, which builds on an intrinsically and maximally
differentiated manifold. The key to that problem is that the fuzziness of a
variable can manifest itself only to the extent that less fuzzy variables
exist. Inasmuch as there is nothing less fuzzy than the metric, this argues
against a quantum-gravity phenomenology and suggests that a quantum theory of
gravity is something of a contradiction in terms - a theory that would make it
possible to investigate the physics on scales that do not exist, or to study
the physical consequences of a fuzziness that has no physical consequences,
other than providing a natural cutoff for the quantum field theories of
particle physics.
