# Physical Permanence Gradient **Domain:** Continuity Architecture / Archival Storage **Doc Type:** Architectural Concept Node **Maturity:** Analytical Framework **Related:** [[Project Silica]], [[Cerabyte]], [[Synthetic DNA Data Storage]], [[Holographic Data Storage]] --- ## Definition The **physical permanence gradient** orders storage media by retention horizon, rewrite behavior, access latency, energy demand, density, environmental tolerance, and dependence on active maintenance. The source article uses this frame to compare glass, ceramic, DNA, and holographic vectors. ## Key insight No medium is simply “permanent.” A record survives only if its physical bits, metadata, decoders, indexes, provenance, custody, and interpretive institutions remain recoverable together.