30. ISO 80000-12 — Condensed matter physics
The ninth part specified in full is ISO 80000-12, Condensed matter physics. Every item —
all of 12-1.1 … 12-38.2, sixty including every sub-suffixed item — is catalogued: the
lattice geometry, the reciprocal lattice and wavenumbers, the Debye and Grüneisen
quantities, the transport and thermoelectric coefficients, the work functions and band
energies, the carrier densities, and the magnetism and superconductivity quantities — each
carrying its exact source as data. Only citation locators are recorded; no normative
content from the licensed standard is reproduced. The defining mathematics of selected
remarks is specified in the sibling module Part12.DefiningRelations.
Condensed matter physics is where dimension does not classify the kind stops being the
exception and becomes the rule: nearly every quantity collides in dimension with several
others. Five families dominate, and each is one big collision — thirteen lengths on L,
seven energies on M·L²·T⁻², five temperatures on Θ, five carrier densities on
L⁻³, and five reciprocal lengths on L⁻¹. The five named temperatures are especially
striking: the Debye, Fermi, Curie, Néel, and superconduction-transition temperatures share
one dimension and one unit (the kelvin), and only the kind tells them apart.