Source: https://guthlabs.ai/docs/instruments/physical-constants-reference/mechanism/

instrument mechanism / verified-clean

# Physical Constants Reference mechanism

The inspectable method record for Physical Constants Reference, kept separate from implementation and qualification.

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

## Model scope

The lookup approach is valid for a physical-constants reference, and the four tested CODATA 2022 rows are standard. Verdict is NEEDS_REVIEW because the supported constant set, alias normalization, missing-key behavior, unit-conversion behavior, and uncertainty representation are unspecified. The honest_label field is empty; it should state that this is a finite, edition-specific reference table rather than a live measurement or universal calculator.

No additional formula finding is recorded.

## Units and conventions

- Values are returned in the CODATA 2022 SI units listed for each constant; no automatic unit conversion is assumed unless explicitly implemented.

- ε0 is reported in F/m, equivalently C/(V·m).

- μ0 is reported in N/A², equivalently H/m.

- For exact SI-defined constants, uncertainty is reported as 0 with an 'exact by SI definition' note, not as an experimental standard uncertainty.

- Constant-name aliases and the supported meaning of 'etc.' are not specified and require an explicit canonical-name list.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "constant_name": "speed of light in vacuum",
    "lookup_alias": "c"
  },
  "expected_outputs": {
    "value": 299792458,
    "units": "m/s",
    "uncertainty": 0,
    "uncertainty_note": "exact by SI definition"
  },
  "reference_data": {
    "constant_name": "c",
    "value": 299792458,
    "units": "m/s",
    "standard_uncertainty": 0,
    "source_convention": "CODATA 2022; exact SI-defined value"
  },
  "working": "1. Normalize the search term 'speed of light in vacuum' to the canonical key c.\n2. Look up the CODATA 2022 row: c = 299792458 m/s.\n3. The value is exact by SI definition, so uncertainty = 0."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

The specification does not define empty-query handling, numeric coercion of search text, exact versus substring matching, or whether electron charge means positive elementary-charge magnitude or signed electron charge. These omissions permit rejected, overflowed, ambiguous, or sign-inverted outputs for valid-looking probes.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/physical-constants-reference/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/physical-constants-reference/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/physical-constants-reference/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`