S² × ℝ (Thurston)

Spherical layering, radial drift
symmetrydim 34 metrics

What It Measures

Whether the data has directional structure that drifts over time.

Maps each byte triple to a point on the sphere (first two bytes give polar angle and azimuth) plus a height on the real line (third byte). This is the Thurston geometry of spherical layers: data with stable directional concentration has high sphere_concentration, while the height coordinate tracks temporal drift in the third-byte channel.

Metrics

sphere_concentration

Norm of the mean direction vector on S² — the von-Mises-Fisher resultant length. Logistic period-3 and Collatz gap lengths score 1.0 (all points cluster at a single direction on the sphere). L-System Dragon scores 0.0006 (nearly uniform coverage of the sphere — the binary symbolic dynamics maps to antipodal directions that cancel). Rainfall also scores 1.0 (its near-zero values all map to the same latitude). Measures DIRECTIONAL bias: 1.0 means one preferred pole, 0.0 means uniform OR antipodally cancelled.

bingham_concentration

Largest eigenvalue of the normalized scatter matrix Σpᵢpᵢᵀ/N. 1/3 ≈ uniform on the sphere, 1/2 ≈ concentrated on a great circle, → 1 concentrated on an axis. The Bingham distribution is the canonical model for axial data on S². Independent of sphere_concentration — Bingham measures AXIAL concentration regardless of direction, so a source whose points cluster along a single axis but split evenly between the two poles scores 1.0 here while sphere_concentration reads 0. Constants, Thue-Morse, Fibonacci Word, and Kolakoski Sequence saturate at 1.0; Wigner Semicircle (0.39) and Ikeda Map (0.45) sit at the diffuse end.

great_circle_dispersion

Mean geodesic distance arccos(pᵢ·pᵢ₊₁) between consecutive sphere points — the actual sphere metric, not Euclidean chord length. Logistic Period-2 (3.14 ≈ π) tops the list because consecutive values map to antipodal points (the diameter is the geodesic max). Period-4 (2.67), Logistic Edge-of-Chaos (2.55), and Noisy Period-2 (2.49) follow. Primes (0.001), Partition Function (0.001), Period-3, and constants collapse to 0 — their consecutive values barely move on the sphere. Distinct from bingham_concentration: that measures global axial structure; this measures step-by-step movement along the sphere.

height_drift

Difference between final and initial height values. Rule 30 scores +1.0 (maximal upward drift) and Morse code scores -1.0 (maximal downward drift). ECG fusion scores -0.60. This captures systematic trends in the third-byte channel that the spherical components do not see.

Atlas Rankings

bingham_concentration
SourceOriginValue
Logistic r=3.83 (Period-3 Window)iterated-maps1.0000
Collatz Paritynumber-theory1.0000
Logistic r=3.2 (Period-2)iterated-maps1.0000
···
Wigner Semicirclerandom-matrix-quantum0.3922
Ramanujan Taunumber-theory0.4102
Ikeda Mapiterated-maps0.4500
great_circle_dispersion
SourceOriginValue
Logistic r=3.2 (Period-2)iterated-maps3.1416
Logistic r=3.5 (Period-4)iterated-maps2.6714
Sine Map (Feigenbaum)iterated-maps2.5537
···
Logistic r=3.83 (Period-3 Window)iterated-maps0.0000
OTOC Growthrandom-matrix-quantum0.0020
Takagi Functionspecial-functions0.0068
height_drift
SourceOriginValue
Rule 30symbolic-dynamics1.0000
Critical Transition (Fold)iterated-maps0.9718
Forest Fireself-organized-criticality0.8190
···
Morse Codesignal-synthesis-1.0000
Pulse-Width Modulationsignal-synthesis-0.8000
ECG Fusionphysiological-0.6043
sphere_concentration
SourceOriginValue
Logistic r=3.83 (Period-3 Window)iterated-maps1.0000
Aubry-André Criticalrandom-matrix-quantum0.9994
Fibonacci Tight-Bindingrandom-matrix-quantum0.9989
···
Logistic r=3.2 (Period-2)iterated-maps0.0002
L-System (Dragon Curve)symbolic-dynamics0.0005
De Bruijn Sequencesymbolic-dynamics0.0013

When It Lights Up

S² × ℝ is the only geometry that decomposes the signal into a directional and a scalar component simultaneously. In the atlas, sphere_concentration separates concentrated signals (periodic, near-constant) from diffuse ones (chaos, symbolic dynamics); bingham_concentration adds an axial-vs-directional axis; great_circle_dispersion measures step-by-step movement along the sphere; and height_drift catches systematic trend in the third-byte channel that the spherical components do not see. This is distinct from what Heisenberg measures (pure correlation twist) and from what Sol measures (exponential anisotropy).

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