Radiocarbon (C-14) Age with Calibration Note

Inspectable records

Ledger state

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

Area

Earth & Space (astronomy, orbital mechanics, meteorology, geology, geodesy, oceanography)

Tranche

tranche-5

Evidence ID

t5-027

Ledger rows

1

No ledger note is attached.

Review findings

The algebra and Libby convention are standard, but the instrument needs an explicit pMC-versus-ratio input mode, conversion rule, and domain behavior before release. The honest label must prominently state: uncalibrated conventional radiocarbon age only; real dates require an external calibration curve that is not bundled.

Formula and scope findings

• The formula t = 8033·ln(1/f) is correct for conventional radiocarbon age when f is a dimensionless fraction modern ratio under the Libby 5568-year half-life convention.
• The input description is ambiguous: pMC means percent modern carbon and must be converted as f = pMC/100, whereas a ratio is already f. The panel must require an input mode or clearly define the conversion.
• The valid mathematical domain and interpretation are not specified: 0 < f <= 1 gives nonnegative conventional ages; f > 1 gives a negative conventional age, and f <= 0 is invalid or divergent.

Unit assumptions

• 8033 years is the Libby mean-life constant, approximately 5568/ln(2), and the output is in years.
• f is dimensionless; ratio inputs are used directly, while pMC inputs are divided by 100.
• BP is conventional radiocarbon years before 1950 CE, not a calendar date.
• The result is uncalibrated; calendar-age conversion requires an appropriate calibration curve such as IntCal.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The raw formula has an undefined input at f=0 and produces a mathematically finite but physically invalid negative age for f>1. A robust instrument must reject those inputs. The pMC-versus-ratio convention is also hazardous unless the representation is explicitly declared.

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": {
    "input_mode": "pMC",
    "value": 100
  },
  "expected_outputs": {
    "fraction_modern": 1,
    "conventional_age_BP_years": 0
  },
  "working": "Convert pMC to fraction: f = 100/100 = 1. Compute 1/f = 1/1 = 1. ln(1) = 0. Therefore t = 8033 × 0 = 0 years BP."
}

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-tranche5/tranche5-results.json
• BOUNDARY_HAZARD_CATALOG.json