What differentiates a field from noise is the capacity to retain structure across time and to render that structure intelligible without diluting its density. Machines can read; increasingly, they can summarise. The threshold now is whether they can clarify without flattening, whether they can expose curvature rather than merely restate surface. If explanation becomes infrastructural rather than decorative, then retention ceases to be mnemonic and becomes systemic. A field persists not because it produces texts, but because it installs explanatory operators that survive recompression.