4.10 Evidence Engineering: How to Test, What Fingerprints to Watch, and What We Predict

Home ／ Chapter 4: Black Holes

This section turns the “material-layer” picture from Sections 4.1–4.9 into actionable evidence. The first half designs verification experiments; the second states falsifiable predictions. After reading, you should know which bands, instruments, and observables can confirm—or refute—the dynamic critical band, the transition layer, and the three escape routes.

I. Verification Roadmap: Three Main Lines and Two Supporting Lines

• Image Plane (mm/sub-mm VLBI): Track the geometric stability and subtle “breathing” of the main ring, sub-rings, and long-lived bright sectors.
• Polarization (per-pixel time series): Follow degree and angle over time; test whether smooth twists and narrow-band flips co-locate with brightness geometry along the ring.
• Timing (de-dispersed, multi-band): Seek common steps and echo envelopes across bands, then check coincidence with imaging and polarization.
• Spectral & Dynamics (supporting): Watch see-sawing hard/soft components, reflection and absorption strength, outward-moving knots, and core-frequency shifts.
• Multi-Messenger (supporting): Look for space–time coincidence with high-energy neutrinos and candidate ultra–high-energy cosmic rays; test energy-budget consistency with merger gravitational waves.

Whenever possible, align all five lines within the same event window. We decide by joint concurrence: no single line suffices; at least three must agree.

II. Test 1: Does a Dynamic Critical Band Really Exist?

What to look for: an almost fixed ring diameter with azimuth-dependent thickness; a sub-ring family—fainter, narrower rings inside the main ring that repeat across nights; and breathing—small but systematic, in-phase changes in ring width and brightness during strong events.

Why it can falsify: if the ring behaves as a perfect geometric line with no sub-ring build-up and no event-tied advance/retreat over long campaigns, then a finite-thickness, breathing layer is illusory. Conversely, a stable main ring plus reproducible sub-rings plus low-amplitude breathing provides direct evidence that the “skin” is not a smooth surface.

Minimal configuration: high-frequency VLBI (e.g., simultaneous 230 and 345 GHz) with dynamic imaging; subtract a ring model and search residuals for stable sub-rings; measure co-variation of ring thickness and brightness before/after strong events.

III. Test 2: Is the Transition Layer a “Piston” Layer?

What to look for: after strong events, common steps that jump almost simultaneously across bands once de-dispersed; then an echo envelope with weakening secondary peaks and lengthening inter-peak intervals; and co-window behavior in imaging and polarization—bright-sector enhancement and more active banded flips.

Why it can falsify: if steps separate strictly by dispersion, or if echo amplitudes/intervals lack a consistent evolution, and imaging/polarization show no co-window changes, remote-medium or instrumental effects are more likely. Our framework requires geometric synchrony when the threshold is pressed and piston-like staged release; both must appear.

Minimal configuration: high-cadence, cross-band light curves (radio to X-ray) on a unified, de-dispersed time axis; synchronous image and polarization slices to test the step–bright-sector–flip triad.

IV. Test 3: Distinct Fingerprints for the Three Escape Routes

1. Ephemeral Pores (Slow Leak)
   • Image: gentle brightening of the main ring locally or globally; inner, finer rings briefly sharpen.
   • Polarization: slight drop in fractional polarization where it brightens; smooth position-angle twist continues.
   • Timing: small common steps and a weak, slow echo.
   • Spectrum: soft/thick components rise; no hard spikes.
   • Multi-messenger: no neutrinos expected.
   • Decision rule: four-line concurrence ⇒ pore clusters dominate.
2. Axial Perforation (Jet)
   • Image: collimated jet with outward-moving knots; weak counter-jet.
   • Polarization: high degree; segment-stable angle; transverse Faraday-rotation gradients.
   • Timing: fast, hard flares; small steps propagating outward along the jet.
   • Spectrum: nonthermal power law with a stronger high-energy end.
   • Multi-messenger: neutrino coincidence possible.
   • Decision rule: majority of five lines ⇒ perforation dominates.
3. Edgewise Band-Like Subcriticality (Wide Reprocessing/Outflow)
   • Image: banded brightening along the ring edge; wide-angle outflows and diffuse glow.
   • Polarization: moderate degree; segmented angle changes within bands; flips adjacent to the bands.
   • Timing: slow rise/decay with color-dependent lags.
   • Spectrum: stronger reflection and blue-shifted absorption; thicker infrared and sub-mm spectra.
   • Multi-messenger: primarily electromagnetic.
   • Decision rule: four-line concurrence ⇒ edge bands dominate.

V. Cross-Checking Scale Effects: Is “Small Fast, Large Steady” Universal?

What to look for: minute–hour flickering and easy jet perforation in low-mass sources; day–month undulations and long-lived edge bands in high-mass sources.

How to do it: apply the same methodology to microquasars and to supermassive black holes. A systematic shift of timescales and load allocation with mass implies the material-layer parameters are at work.

VI. Falsification Checklist: Any One Negates a Major Part of the Framework

• Over long, high-quality campaigns the main ring remains a perfect line with neither sub-rings nor breathing.
• After de-dispersion, cross-band steps are not co-window and show no relation to imaging or polarization.
• During strong, hard jet outbursts there is no co-located activity in the near-core ring or bright sectors, and no axial polarization signatures ever appear.
• Clear edge-band brightening never coincides with stronger reflection or disk-wind fingerprints.
• No systematic differences in timescales and load allocation between low- and high-mass sources.

VII. Predictions: Ten Phenomena Next-Generation Observations Should See

• Sub-Ring Families: two to three stable, narrower, fainter rings inside the main ring at higher frequencies and longer baselines; higher orders light up more readily after strong events.
• Bright-Sector “Fingerprint Phase”: a statistical preference in relative azimuth between long-lived bright sectors and polarization-flip bands; after strong events the phase offset reorders quickly, then relaxes back.
• Truly De-Dispersed Steps: near-simultaneous jumps persist across millimeter, infrared, and X-ray after de-dispersion, accompanied by synchronous changes in ring width and polarization bands.
• Breath–Step Resonance: a linear co-variation between small ring-thickness expansions and common-step heights, with stronger correlation for stronger events.
• Perforation Trigger Sequence: hard jet flares precede or coincide with short-lived brightening of near-core sectors, followed by moving knots and core shift.
• Edge-Band “Sooty” Spectrum: when edge bands dominate, infrared/sub-mm thick spectra rise before hard X-rays, with reflection and blue-shifted absorption strengthening over days to weeks.
• Pore-to-Perforation Transition: repeated co-located pore events near the spin axis convert into a stable jet within days to weeks, with an overall rise in polarization degree.
• Scale vs. Timescale: minute-scale step–echo patterns appear more in microquasars; day–week patterns are common in supermassive black holes, with slower growth of echo-peak spacing.
• Neutrino Coincidence: mid-energy neutrino events are more likely during strong perforation intervals and are in phase with hard-γ spikes.
• Band-Flip–Disk-Wind Co-Location: as polarization-flip bands slide along the ring edge, the depth of X-ray disk-wind absorption co-varies, with a repeatable phase relation in position-angle rotation.

Each item is independently testable. Systematic failure of any one requires mechanism-level revisions to the framework.