REJ:2026.08.07.0001 · neuro.CJ (Neuro-Conjecture) · Rejected
Rohan Kadambi, Elke Tervoort, Chidi Onuoha, Paloma Ferreiro Cruz & The Six-Site Volatile Survey
Comments: 6 pages, 7 figures, 0 reproducible results. Rejected in 36 minutes on Aug 7, 2026.
Abstract: Vision has three primaries. Hearing has one continuous axis. Smell, by long consensus, has neither: there is no set of elementary odours from which the rest can be mixed, and published estimates of the dimension of odour space range from two to thirty depending on which corpus was measured. We report that the dimension is six, and that the instability of the earlier estimates is what a compositional geometry looks like when it is analysed in Euclidean coordinates. Between March 2019 and October 2025 the Six-Site Volatile Survey collected 41,206 dynamic headspace samples at six type sites chosen to be maximally separated in substrate and thermal regime. Non-negative factorisation of the panel–descriptor matrix (214 trained assessors, 6,410 profiled samples, 418 consensus descriptors) admits a rank-6 solution accounting for 97.4% of panel-explainable variance; the seventh factor adds 0.31 percentage points, and cophenetic correlation falls from 0.994 to 0.951 across that step. Bootstrap over the assessor pool returns hat k =6 in 981 of 1,000 resamples. Perceived quality is scale-invariant and therefore compositional; on the simplex mathcal S 5 the mixture of two odours is exactly perturbation, mathbf q (A oplus B)= mathcal C [ mathbf q (A) w A odot mathbf q (B) w B ] , with median Aitchison error 0.084 over 6,120 binary blends against 1.71 for linear mixing, and 0.097 over 1,880 ternary blends predicted with no free parameters. We then built the basis. A six-cartridge delivery device reconstructed 1,204 target odours drawn at random from a commercial library; under triangle test, 41 assessors identified the reconstruction at 34.0% (95% CI 32.9 – 35.1 ) against a chance rate of 33.3%. We name the six primaries for the type sites at which each was recovered in near-pure form. A seventh component is present in 1.9% of field samples, 771 of 784 of them collected above 2,400 m, and in the targets that were discriminated. We have not accounted for it, and we do not report it as a primary.