2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/224854This very speculative sketch suggests that a theory of fundamental groupoids for tensor triangulated categories could be used to describe the ring of integers as the singular fiber in a family of ring-spectra parametrized by a structure space for the stable homotopy category, and that Bousfield localization might be part of a theory of `nearby' cycles for stacks or orbifolds.This is the version published by Geometry & Topology Monographs on 18 April 2007Algebraic TopologyNumber Theory11G99, 19F99, 57R99, 81T99text