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

instrument / verified-clean

# Physical Constants Reference

The current ledger marks this instrument verified clean within the source-bound verification corpus.

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

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/physical-constants-reference/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/physical-constants-reference/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/physical-constants-reference/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/physical-constants-reference/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

**Tranche**: tranche-7

**Evidence ID**: t7-021

**Ledger rows**: 1

No ledger note is attached.

## Review findings

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.

### Formula and scope findings

No additional record

### Unit assumptions

- 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.

## Boundary hardening

**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.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "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."
}
````

## Related workflows

No source-defined multi-instrument workflow membership is recorded.

## Sources and evidence

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

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

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

- `BOUNDARY_HAZARD_CATALOG.json`