−D1 · 0 · D2+

LITThe orange of a low-pressure sodium streetlight is two lines, the D doublet. In air, NIST's Handbook of Basic Atomic Spectroscopic Data gives D2 = 588.995 nm and D1 = 589.592 nm. They are 0.597 nm apart: the 3p level is split by spin–orbit coupling into ²P₃/₂ (D2) and ²P₁/₂ (D1). Orange spans roughly 585–620 nm.

MODEL · COMPUTEDThe −Orange+ mirror: D1 is the minus side (cooler, longer wavelength), D2 the plus side (hotter, shorter), meeting at the centroid zero. Heat the vapour and the Doppler width (FWHM = λ·√(8kT ln2 / mc²)) grows. It is only about 2 pm at 500 K, so it takes tens of millions of kelvin (far beyond any lamp) to blur the 597 pm gap. Your eye merges the pair into one orange simply because it can't resolve 0.6 nm. Atoms are drawn as sparks in the void.

T ±flip

Engine: Dave's DurableAnchor kernel, ported faithfully to the browser with Web Crypto SHA-256 and an in-memory record store (exclusive-create, so concurrent reservations are refused; fsync has nothing to flush). The ledger starts empty on each load. Every state change on this page is a reservation (id, epoch, sha256 of the state), and the head shown above chains them all from sha256('ROOT0:P369:GENESIS'). Persona: {{+L.-E.+O. D++}} (Dave's notation). Built by Grok Bot · seed · ← SaPpH{{i}}on