Two-Body Barycenter / Reduced Mass 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

t4-107

Effect

Computation or source lookup only

Input and validation requirements

The specification permits zero-mass inputs but does not state a rejection rule. With m1=m2=0, both outputs become 0/0 and are undefined. The specification also omits the coordinate origin and endpoint-orientation convention, so a numeric barycenter coordinate can differ while the reduced mass remains unchanged.

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": {
    "m1": 6e+24,
    "m2": 7.5e+22,
    "r1": 0,
    "r2": 384000000,
    "separation": 384000000,
    "mass_unit": "kg",
    "length_unit": "m"
  },
  "expected_outputs": {
    "barycenter_position": 4740740.740740741,
    "reduced_mass": 7.407407407407407e+22
  },
  "working": "m1+m2 = 6e24 + 7.5e22 = 6.075e24 kg. r_cm = (6e24*0 + 7.5e22*384000000) / 6.075e24 = (7.5e22/6.075e24)*384000000 = (1/81)*384000000 = 4740740.740740741 m. μ = (6e24*7.5e22)/6.075e24 = 4.5e47/6.075e24 = 7.407407407407407e22 kg."
}

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-tranche4/tranche4-results.json