The Copenhagen–Everett Bridge

What the paper does

Copenhagen and Everett have been treated as competitors for seven decades, with the Born rule as the wedge between them. This preprint argues the wedge is not interpretive but conservational: if information is a conserved quantity at the substrate level, in the same sense that energy is conserved, then the observer-level theory inherits a unique consistent weighting rule, and that rule is the Born rule. Copenhagen’s collapse becomes bookkeeping at the observer level; Everett’s branches become sectors at the substrate level; and the two pictures stop being rivals because they are descriptions of different levels of one architecture.

The technical content is a two-level consistency theorem and a no-go: no operation available inside a branch can transfer substrate-level information across the branch boundary, except through a channel that is exponentially suppressed and structured rather than thermal. That no-go is what keeps the two levels from contaminating each other, and it is also what makes the framework’s test programme meaningful rather than decorative.

Where it sits in the wider archive

This is the peer-document version of the architecture covered in the foundations series of this blog: the Information Conservation Principle, the two-level split, and the bridge post on this site. The companion SSRN papers cover the boundary-permeability field and the resource theory of novelty. Nothing here claims a detection; the claim is a theorem plus a no-go, with the falsifiable consequences relegated to the test series.