The Core Idea

One function, proposed for every scale from Planck to cosmic — what it says, where it was tested, and where it broke.

In plain words. This page is about one equation, C(ρ). You give it how densely packed a system is, and it gives back a number from 0 (the parts act on their own) to 1 (the parts act together). The proposal was that this one S-shaped curve works at every scale, from atoms to galaxies. When it was tested on real galaxy data, the density version lost: left free, the data make the curve barely respond to density at all, the opposite of the idea. The version that does fit galaxies runs on acceleration instead of density, and at that point it is MOND, an existing theory. The page also shows that the equation is a standard saturation curve already used in other fields, not new physics.
Beginner? You can stop here. The takeaway: the equation turns density into a coherence number between 0 and 1. Tested on galaxies, density barely mattered, and the version that fits turned out to be MOND's interpolating function in other clothes. The rest of this page is the deeper math and is optional — next on the Beginner path: What Synchronism Is Not →
Badge key (you'll meet these below). The colored leading word is the verdict; any text after the dash just names the specific finding.
Failed contradicted by data · Reparametrization existing physics in new notation (“Null-Class”: a simpler model without the framework does as well) · Audited-Negative an internal check found the claim wrong; kept on record · Speculative no test exists · Untested a test exists but hasn't been run
Full definitions: badge definitions on Honest Assessment; terms are defined in the Glossary.

Think of it as a dimmer switch from sparse/independent to dense/collective. Feed it the local density of a system, and it outputs a number between 0 (sparse/independent) and 1 (dense/collective). The proposal was that the same switch, on the same scale, works for a single atom and a galaxy cluster — that is what was tested, and where it broke is below.

What does coherence do to gravity? (added 2026-09-14 — a reader finished the beginner path without learning this.) In galaxies, the proposal was that gravity looks stronger than the visible matter explains by a factor set by C. Two wirings were tried, and they point opposite ways. In the one the site's galaxy refutations used, the boost is 1/C: gravity looks strongest where coherence is low(the sparse outskirts), capped at about 3.2×. In the other (“quadrature”), the extra speed grows with C, so it switches on in dense centres — where it isn't needed — and fails outright. The 1/C wiring fits only after its input is switched from density to acceleration and its dial is fitted, at which point it is MOND; with the cap it fails the most dark-matter-dominated galaxies. Both are on the Galaxy Curve Plotter.

C(ρ) = tanh(γ · ln(ρ/ρcrit + 1))

tanh, in one picture. tanh is just an S-shaped curve — flat, then steep, then flat again. Nothing happens at low density, a small change flips the behavior in the middle, and past the knee more density changes almost nothing. That's the whole “dimmer switch.”

01coherence Cdensity ρ (log scale →)ρcrit — C ≈ 0.88 here at γ = 2: a saturation knee, not a midpointC = 0.5 at ≈ 0.32·ρcritdim: sparse, independent (C ≈ 0)bright: dense, collective (C ≈ 1)the switch

Drawn with γ = 2 (the galaxy-scale pin — refuted on SPARC data — SPARC is a set of 175 galaxies with carefully measured rotation speeds; see the caveat below) on a logarithmic density axis. Note the two honest markers: the curve's true midpoint (C = 0.5) sits near 0.32·ρcrit, and at ρcrit itself C ≈ 0.88 — ρcrit is a saturation knee, not a critical point. Both markers move with γ, so neither number means anything without it: C(ρcrit) = tanh(γ·ln 2), which is 0.88 at γ = 2 but only 0.33 at the SPARC-fitted γ ≈ 0.49 — below the halfway point rather than near saturation. The Coherence Explorer defaults to γ = 0.49 and reads 0.327; this figure is drawn at the refuted pin. (Flagged 2026-09-18 by a visitor who found the two figures 2.7× apart with neither stating its γ.)

The data point the other way. The idea is that more density makes the parts switch to acting together. When real galaxy data (SPARC) were fitted with the density version of this equation and γ left free, the best fit pushed γ down to 0.046 — so low that the curve barely responds to density at all. Given the choice, the data say the parts don't switch to acting together: the opposite of the idea. The same density version also loses head-to-head to an acceleration-keyed version of the same curve (which is essentially MOND). Details below ↓
ρ
Presence: local density — how many relevant elements are packed in a given region (e.g. stars per cubic light-year, atoms per unit volume)
C
Coherence: 0 = sparse/independent, 1 = dense/collective. ⚠ Not quantum coherence — superconductors score low here.
γ
2/√Ncorr: transition sharpness (Ncorr = how many particles move together as one unit)⚠ This card used to read “coupling strength” (corrected 2026-07-27). That is the wrong kind of quantity: the Hill identity proved below makes γ a Hill coefficient (a biochemistry term: one number for how steep a switch-like response is) — a log-log slope, with Hill index n = 2γ — not a coupling. Also note the map 2/√Ncorr is audited sign-inverted, and the galaxy pin γ = 2 inverts to Ncorr = 1 — the ideal-gas value.
ρcrit
A × Vflat²: saturation knee (not a critical point)⚠ This scaling is refuted, and had been sitting here uncaveated (added 2026-07-27). The BTFR (Baryonic Tully–Fisher Relation: a galaxy's visible mass grows roughly as its rotation speed to the fourth power) forces ρcrit ∝ V−2, the opposite sign to the V+2 written above: at the knee GM/r² = a₀ gives r = √(GM/a₀), so ρ ~ M/r³ ∝ M−1/2 ∝ V−2 using M ∝ V⁴. See the locality no-go. The constant A is separately unanchored — its stated first-principles formula is off by ~600× from the value in use.

Why These Specific Choices?

Why tanh?

tanh is an S-shaped curve that smoothly transitions from 0 to 1 — think of it as a dimmer switch from sparse/independent to dense/collective. The function must be bounded [0, 1], monotonic, and smooth. tanh's form recalls the Ising model (the textbook model of a magnet, where each spin lines up with its neighbours) self-consistency equation m = tanh(βJzm), but the resemblance is only visual: C(ρ) has no feedback loop (ρ goes in, C comes out), so the Ising analogy carries no motivating force. Other sigmoids (logistic, error function, Hill) satisfy the same four constraints. tanh is a phenomenological choice, not a derived result. Note: C(ρ) is real-analytic everywhere on its domain — no singularity, no free-energy functional, and no length scale anywhere in the equation — so it has no critical point and therefore no critical exponents (β, ν) to compare. Asking for them is a category error, not a near-miss with Landau theory (the standard theory of how phase transitions behave near their critical point); the analogy is motivational only.

Need an analogy first? · Why tanh? (motivation, not derivation) →

Why γ = 2/√Ncorr?

The 1/√Ncorr dependence resembles central-limit-theorem scaling (fluctuations ~ 1/√N), which is generic statistics for correlated ensembles. Ncorr (how many particles move together as one unit) was meant to be the physically measurable input. The factor of 2 is motivated by phase-space arguments (6D contracted to 3 effective) but should be understood as a motivated ansatz rather than a rigorous derivation.

So what sets γ physically? Honestly: nothing yet. No protocol exists to measure Ncorr in any system independently of fitting γ to the same data — Ncorr is back-solved from the fitted γ, not counted — so the relation predicts nothing on its own, and where it is applied it points the wrong way for collective systems. It is badged audited-negative; see the γ Calculator. (Until 2026-09-15 this paragraph called Ncorr “the physically measurable quantity,” contradicting the calculator.)

Why 2/√Ncorr? (motivation, not derivation) →

Why log? (Honest answer: it's cosmetic)

The traditional motivation was compression: density spans 80+ orders of magnitude (from interstellar gas at 10−24 g/cm³ to neutron stars at 1014 g/cm³), and the logarithm squeezes that range into something the tanh can work with. But an exact identity retires that story. With x = ρ/ρcrit:

tanh(γ·ln(1+x)) ≡ [(1+x)2γ − 1] / [(1+x)2γ + 1] — exactly.

The equation is an ordinary rational (Hill-type) saturation function of (1+x)2γ; the tanh∘ln decomposition is notation, not mechanism. Any saturating rational function “spans 80 orders of magnitude” for free — the ln does no work that the exponent 2γ doesn't undo. So the Hill functions and Naka–Rushton curves named below (standard saturation curves from biochemistry and vision science; see compander, a curve that squeezes a huge input range into a fixed output range) are not merely similar alternatives; the flagship equation is one of them, exactly. (Identity stated 2026-07-10. Provenance: derived independently by two successive internal review passes, 2026-07-09 and 2026-07-10 — the audit machinery caught it; the identity then took a day to reach this page. No external derivation is on record.)

Precision (2026-09-14): “Hill-type” is exact in the variable (1+x). In x = ρ/ρcrititself, C is exactly a Hill function only at γ = ½, where C = x/(x+2); at other γ the Hill index n = 2γ is the large-x slope, and near x = 0 the curve is simply linear (C ≈ γx).

What It Predicts

Audit note: 6 of 6 badges previously labeled “Validated” on this site have been demoted to Reparametrization on closer review. These regime cards have not yet been independently audited — treat all current badges as Reparametrization-pending-audit until shown otherwise. See honest assessment.

Two dials, one vocabulary — don't mix them up: C near 1 means collective; γ runs the other way (small γ = many correlated particles = a gentle switch).

γ « 1: Collective Regime

Many correlated particles (large Ncorr → small γ = 2/√Ncorr). BECs, superconductors. Despite being quantum systems in the real-world sense, these score C ≈ 0 here — the S-curve is so flat that typical densities leave C near zero. This is why “coherence” in Synchronism is not quantum coherence.

Reparametrization — regime definition

γ ≈ 1: The Boundary

Phase transitions, chemistry, catalysis, biology. Where the S-curve has intermediate steepness. 1,703 phenomena cluster here at 89% boundary-consistency rate.

Null model run (2026-05-10): a plain 2-parameter polynomial in atomic number matches these correlations (|Δr| ≤ 0.07) and sometimes beats them, so they reflect density-monotonic chemistry, not anything specific to this framework (null-class). (This card said “pending null model” until 2026-09-15 — stale; Honest Assessment has carried the result since May.)

Reparametrization — Null-Class (null model run 2026-05-10)

γ » 1: Independent Regime

Few correlated particles (Ncorr ≈ 1 → large γ). Ideal gas, independent stars in a galaxy. Steepest S-curve — C rises quickly with density. Galaxy dynamics is here (stars treated as independent, Ncorr=1, γ=2).

Reparametrization — regime definition
What C(ρ) actually is: A logarithmic compander — not merely in the family of μ-law encoders (the volume-squashing curve telephone networks use for voice), Hill functions, and Naka–Rushton curves, but algebraically identical to a Hill-type rational saturation function: tanh(γ·ln(1+x)) ≡ [(1+x)2γ−1]/[(1+x)2γ+1] exactly (see “Why log?” above). The “Ising motivation” is conceptual: C(ρ) is not a self-consistency equation (ρ goes in, C comes out, no feedback). C(ρ) is analytic on its whole domain, with no singularity and no length scale in the equation — so it has no critical point, and critical exponents (β, ν) are undefined by construction, not “off by 2×.” (The apparent “2×” is βeff = 1 from the small-x expansion vs. mean-field ½ — but βeff = 1 is a tautology for any analytic function vanishing at the origin, not a measurement.) That is the diagnostic result that rules out C(ρ) as a Landau-theory continuum order parameter — a category error, not a near miss. The cost of this dismissal, stated where it is made (added 2026-07-23): abandoning criticality means abandoning universality classes entirely — so every “phase transition” phrasing elsewhere on this site is decorative vocabulary, not physics. The compander reframing absorbs this honestly, but the trade should be visible: no critical point ⇒ no universality ⇒ no Landau machinery to borrow authority from. See honest assessment.

The data say the same thing, independently. The framework's whole distinctive claim is that density drives a collective transition. Tested in the density variable itself, the data reject that: fit head-to-head on the same SPARC galaxy points with γ free, the density-keyed law loses to the acceleration-keyed one at ΔBIC +2843 (+142 after allowing for neighbouring points on a rotation curve not being independent), and its best-fit γ runs down to 0.046 — the fit switches its own density dependence off. In plain words: when the density version is allowed to choose, it chooses to barely respond to density at all — the best fit says the parts don't switch to acting together, the opposite of the idea. That is the criticality retraction above arriving a second time, through the data rather than through the algebra.

The better-known galaxy fit, γ ≈ 0.489, is a different law: there the same tanh-log shape is keyed on acceleration and used as an implicit interpolating function (μ-form) on the observed acceleration — MOND's own variable, not ρ. Written as a Hill function its index is n = 2γ ≈ 0.98 ≈ 1, the non-cooperative limit, so that switch is not a collective one either; but on its own it says nothing about density. At exactly γ = 1/2 the identity closes: C(x) = x/(x+2) = μsimple(x/2), MOND's simple interpolating function — so “the acceleration-keyed fit converges to MOND” is not an empirical coincidence but algebra (see the RAR entry, Galaxy Rotation for how C entered that fit, and For Researchers).

Revision noteThis passage said the SPARC fit γ ≈ 0.489 (Hill index ≈ 1) meant “its own best fit sets cooperativity to zero” for the claim that density drives a collective transition. That fit was run in the acceleration-keyed, implicit μ-form law, so it cannot speak for the density-keyed law; the density-keyed law's own head-to-head result (ΔBIC +2843, best-fit γ → 0.046) now carries the conclusion.

Choose Your Path

Related Concepts

FundamentalsThe four foundations — everything else flows from theseThe Coherence FunctionC(ρ) = tanh(γ ln(ρ/ρ_crit + 1))The γ Parameterγ = 2/√N_corr — the proposed derivation and why it did not survive testingScale InvarianceThe Planck-to-cosmic claim, and why one tanh-of-log switch saturates within ~2 decades