Radiometric Dating Calculator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t7-088

Effect

Computation or source lookup only

Input and validation requirements

The exact zero-parent input makes the formula undefined and must be rejected. A separate specification hazard is the unclarified ratio direction: interpreting the stated parent/daughter ratio versus the formula's daughter/parent ratio produces substantially different ages.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "isotope_system": "C-14 -> N-14",
    "parent_daughter_ratio_convention": "radiogenic_daughter/remaining_parent",
    "D_over_P": 1,
    "initial_D_over_P": 0,
    "half_life_unit": "years"
  },
  "expected_outputs": {
    "age_years": 5730
  },
  "reference_data": {
    "isotope": "C-14",
    "half_life_years": 5730,
    "source_convention": "IUGS-recommended/conventional radiocarbon half-life; widely tabulated standard value",
    "ln_2": 0.6931471805599453,
    "ln_2_source_convention": "mathematical constant"
  },
  "working": "lambda = ln(2)/half-life = 0.6931471805599453/5730 yr = 0.00012096809 yr^-1.\\n1 + D/P = 1 + 1.0 = 2.\\nt = ln(2)/lambda = 0.6931471805599453/0.00012096809 yr = 5730 yr.\\nEquivalently, D/P = 1 means one half-life has elapsed, so age = 5730 yr."
}

Other records

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