Lineum Extension — Silent Gravity
Document ID: lineum-extension-silent-gravity
Version: 1.0.0
Status: Draft
Relates to: lineum-core.md §6.1
Compatibility: core ≥1.0.0,<2.0 ; Eq=4 ; κ static ; 2D periodic
Date: 2025-08-19
1. Abstract
We formalize Silent Gravity: an emergent, force-free tendency whereby linons statistically accumulate in low-|∇φ| regions and near φ-minima, and migrate along +∇φ as defined by the canonical update. The effect is quantified via dwell-time enrichment, basin-attraction metrics, and return-bias analyses, without introducing any explicit long-range force term. We provide operational tests, metrics, and replication guidance under the canonical 2D, periodic-BC regime.
2. Motivation
The core paper reports attraction via the φ-gradient and an interpretive note on a quiet, metric-like role of φ. This extension separates the concept into falsifiable claims with measurable criteria so independent groups can test Silent Gravity without modifying Equation (1).
3. Scope & Assumptions (canonical)
- Dimensionality: 2D discrete grid, periodic BCs.
- κ: static spatial map (no time evolution).
- Inputs: time series of ψ (magnitude/phase) and φ (value, ∇φ), plus run metadata.
- Out of scope: dynamic-κ variants, 3D, non-periodic boundaries.
4. Phenomenon Definition
Silent Gravity = The statistical tendency of linons to (i) dwell longer in neighborhoods with low |∇φ|, (ii) accumulate near local φ-minima (or quiet basins), and (iii) drift along +∇φ (environmental guidance), all without an explicit force term in the canonical update.
5. Operational Tests & Metrics
5.1 Dwell-Time Enrichment vs. |∇φ|
- Partition the domain into quantile bins of |∇φ| (e.g., Q1…Q5 per frame).
- For each bin, accumulate linon-centered dwell time.
- Metric: Enrichment ratio
ER = dwell(Q1) / dwell(Q5). - Pass criterion (example):
ER > 1.5with 95% CI not overlapping 1 across ≥3 runs.
5.2 Basin Capture at φ-Minima
- Detect local φ-minima via discrete Laplacian and neighborhood checks.
- Measure arrival rate and average residence within a fixed radius
r_min. - Metric:
Capture Δ = arrival_rate(minima) – arrival_rate(controls). - Pass:
Capture Δ > 0with bootstrap CI excluding 0.
5.3 Directed Drift Along +∇φ
- For each tracked linon, compute instantaneous displacement
Δxand the local gradient directiong = ∇φ / |∇φ|. - Metric: mean cosine alignment
⟨cos θ⟩ = ⟨ (Δx · g) / (|Δx||g|) ⟩. - Pass:
⟨cos θ⟩ > 0with permutation-test p < 0.01.
5.4 Quiet-Basin Stability
- Identify quiet basins: neighborhoods with |∇φ| below the 20th percentile and Laplacian indicating an extremum.
- Compare survival curves (Kaplan–Meier) of linon residence inside basins vs. matched non-basin controls.
- Metric: hazard ratio
HR = hazard(basin) / hazard(control). - Pass:
HR < 1with CI below 1.
5.5 Null & A/B Controls
- Null shuffle: randomize φ fields per frame (preserve histogram), recompute metrics → all effects should collapse toward null (ER ≈ 1, ⟨cos θ⟩ ≈ 0).
- A/B κ-maps: island vs. constant κ to examine robustness of basin identification and metrics.
6. Results (empirical summary)
- Linon dwell time concentrates in low-|∇φ| neighborhoods; enrichment persists across seeds and grid sizes.
- Arrival and residence near φ-minima exceed matched controls.
- Mean alignment with +∇φ is significantly positive even with moderate noise.
- Survival analyses show longer residence within quiet basins.
(Numerical tables belong to validation; this extension remains protocol-oriented.)
7. Discussion
Silent Gravity reframes “attraction” as environmental guidance by φ-topology: φ supplies a quiet, metric-like structure that shapes where |ψ|² accumulates and for how long. No explicit long-range force is introduced; the observed behavior follows directly from local updates and gradients.
8. Limitations & Failure Modes
- Sensitive to φ-estimation quality and gradient discretization.
- Extremely flat φ landscapes reduce effect sizes (need larger samples).
- Basin detection thresholds can bias capture metrics; pre-register parameters.
9. Reproducibility Checklist
- Publish seeds, κ-map definition, parameter dump.
- Export per-frame linon positions, φ, ∇φ, and basin masks.
- Provide scripts/notebooks for binning, survival analysis, and null shuffles.
- Report CIs and effect sizes for all metrics (ER, Δ, ⟨cos θ⟩, HR).
10. Appendix — Minimal Pseudocode
# inputs: trajectories, phi, grad_phi, basin_mask, frames
bins = gradphi_quantile_bins(grad_phi, q=5) # per frame
ER = dwell_time(bins[0]) / dwell_time(bins[-1]) # Q1 vs Q5
minima = detect_phi_minima(phi)
capture_delta = arrival_rate(trajectories, minima) - arrival_rate(trajectories, controls)
align = mean_cosine_alignment(trajectories, grad_phi) # <cos θ>
surv_basin = km_curve(residence_times(trajectories, basin_mask=True))
surv_ctrl = km_curve(residence_times(trajectories, basin_mask=False))
HR = hazard_ratio(surv_basin, surv_ctrl)
null_ER, null_align = null_shuffle_tests(phi, grad_phi, trajectories)
11. Versioning & Changelog
Policy. Semantic Versioning applies to this document; compatibility with the core is pinned in the header.
1.0.0 — 2025-08-19 (initial) — operational metrics (enrichment, capture, alignment, survival), null/A-B controls, canonical 2D scope.