A nuclear · electronic clock-comparison test of General Relativity's deepest unverified assumption.
Every clock ticks against a different physical mechanism. Atomic clocks like Sr-87 tick on an electronic transition — an electron jumping between energy levels in the outermost shell. The frequency is set by the Rydberg constant and the fine-structure constant αem: the electromagnetic sector. Nuclear clocks like Th-229 tick on a nuclear transition inside the atomic nucleus, where the frequency is set by the strong interaction scale ΛQCD and the quark masses: the strong-force sector.
Under General Relativity's universality assumption, the ratio R is constant regardless of gravitational potential. Both clocks must dilate by exactly the same factor √(1 + 2φ/c2), so their ratio cancels out. Under a scalar-field model with sector-dependent coupling, the ratio modulates with the potential:
What has not been emphasized in standard reviews is that every gravitational time-dilation test in history was performed within a single physical sector. The headline results are real and the precision is extraordinary — but no experiment has ever bridged the seam between two sectors of the Standard Model.
| Year | Experiment | Sector compared | Type |
|---|---|---|---|
| 1960 | Pound–Rebka (Fe-57 gamma rays) | photon ↔ photon | EM |
| 1971 | Hafele–Keating (Cs atomic clocks on airliners) | electronic ↔ electronic | EM |
| 2010 | Chou et al. NIST (Al+ optical, 33 cm) | electronic ↔ electronic | EM |
| 2022 | Bothwell et al. JILA (Sr ultracold, mm) | electronic ↔ electronic | EM |
| 2024 | Th-229 nuclear isomer clock first demonstrated | nuclear — new sector | QCD |
| PROPOSED | Th-229 · Sr-87 ratio under annual solar modulation | nuclear ↔ electronic | CROSS-SECTOR |
This is what makes V3 different from V1 and V2. Until 2024 the experiment was not physically possible. The clock didn't exist. Now it does. The seam between geometric proper time and process-dependent proper time can finally be measured.
The V2 simulation tried a direct approach: take a radioactive sample to altitude, count decays, compare against an atomic clock. The math was unforgiving. To detect a 1% deviation from GR (α = 10-2) at GPS orbit altitude, the signal is roughly 5×10-12 — tiny but well above modern clock noise.
The clock can do it. Modern optical lattice clocks have a flicker floor near 10-18. The clock is not the problem.
The problem is Poisson counting. To measure a decay rate to a fractional precision of 5×10-12, you need N ≈ 3.5×1022 counts. A 1 GBq lab source with a 30% efficient detector takes 3.39 million years to gather enough counts. To bring that to a month requires an effective activity of 1 EBq — the radioactive inventory of an entire commercial reactor core, measured with perfect efficiency. Not a laboratory experiment.
Instead of counting nuclear decays against an atomic clock at altitude, V3 proposes:
The Earth itself becomes the experimental apparatus. We don't need to lift anything to GPS orbit. The Sun lifts and drops us by 3% of the Earth-Sun distance every six months — an annual gravitational potential modulation already present, already free, already periodic.
Phase-quadrature analysis against current clock-noise budgets gives a clean prediction for how tightly one year of co-located monitoring constrains the universality violation.
The numbers come from chronal_clock_sensitivity_v2.py — phase-quadrature analysis with a null-distribution histogram and lunar-tidal cross-check. The clock-noise model uses published Allan deviation floors and assumes co-location cancels any common-mode environmental drift.
The Temperature Gauge and the Universality Seam look like different domains — stocks at one end, gravitational physics at the other. They are the same generating rule at two scales. Each one watches a ratio drift away from a φ-gravity rest position and waits for the moment the spring is loaded.
Same generating rule, new scale. The Temperature Gauge is the chair-testable instance of the pattern; the Universality Seam is the physical instance. Both are watching a ratio breathe.
Everything below is in the FreeLattice repository — reproducible, open, free.
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[2] Th-229 nuclear-clock demonstration sequence, 2024 (PTB, JILA, TU Wien collaborations).
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