Source: https://guthlabs.ai/docs/instruments/plate-motion-rate-distance-projector/mechanism/

instrument mechanism / verified-clean

# Plate Motion Rate & Distance Projector mechanism

The inspectable method record for Plate Motion Rate & Distance Projector, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The arithmetic method is valid for a constant scalar rate, but the instrument specification is incomplete for a scientifically honest plate-motion lookup tool. The preset table needs a defined source release, reference frame, epoch, geographic basis, and vector-to-scalar reduction method. The UI must explicitly support and validate the inverse operation t = d/rate.

- The distance formula d = rate × time is correct for constant scalar speed with consistent units.

- The claimed inverse operation, time to travel a distance, requires the additional formula t = d ÷ rate; that inverse formula is not stated.

- A named tectonic plate does not uniquely determine one scalar velocity. Plate motion is a vector whose magnitude and direction depend on the reference frame, geographic location, observation site, epoch, and selected model.

- The preset-rate table must specify its model/version, reference frame, epoch, geographic reference point or averaging method, and whether each value is a magnitude or a signed component.

- The instrument needs a constraint that rate must be positive and nonzero for time-to-distance calculations; zero rate causes division by zero and negative scalar rates are ambiguous unless direction is represented separately.

- For very long geological time spans, constant present-day rate extrapolation is scientifically unsuitable unless the result is explicitly labeled as a kinematic projection rather than a historical reconstruction.

## Units and conventions

- Rates are interpreted as centimeters per Julian year unless the input explicitly specifies another time unit.

- The Julian year is exactly 365.25 days under the IAU standard convention; for rate calculations, years are treated as the same unit on both sides, so the day conversion is not needed unless the user enters days.

- SI decimal length conversions are exact: 1 m = 100 cm and 1 km = 100000 cm.

- Distance is treated as the scalar magnitude of displacement along a straight-line path; no spherical-geodesic correction or direction calculation is included.

- Preset rates are assumed to be rounded representative scalar magnitudes, not complete plate-motion vectors.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "operation": "distance",
    "rate": 1,
    "rate_unit": "cm/yr",
    "time": 365.25,
    "time_unit": "Julian years",
    "plate": "custom"
  },
  "expected_outputs": {
    "distance_cm": 365.25,
    "distance_m": 3.6525,
    "distance_km": 0.0036525
  },
  "reference_data": {
    "custom_rate_cm_per_year": 1,
    "source_convention": "User-specified custom rate; 1 cm/yr is a realistic slow plate-motion magnitude",
    "julian_year_days": 365.25,
    "julian_year_source_convention": "IAU standard Julian year, exact convention",
    "centimeters_per_meter": 100,
    "kilometers_to_centimeters": 100000,
    "length_conversion_source_convention": "SI decimal-prefix definitions, exact"
  },
  "working": "d = rate × time = 1.0 cm/yr × 365.25 yr = 365.25 cm. Convert to meters: 365.25 cm ÷ 100 cm/m = 3.6525 m. Convert to kilometers: 3.6525 m ÷ 1000 m/km = 0.0036525 km. The 365.25-day Julian-year table entry is exact, although the calculation cancels the year unit directly."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

The inverse time operation is undefined for zero rate and must reject distance=100 cm with rate=0 cm/yr. A second hazard is the unclarified treatment of negative custom rates, which can produce either signed displacement or an invalid input depending on the UI convention.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/plate-motion-rate-distance-projector/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/plate-motion-rate-distance-projector/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/plate-motion-rate-distance-projector/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche7/tranche7-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`