Relativistic Velocity Addition Calculator mechanism

Model scope

The instrument can pass after the input convention is resolved. Recommended contract: accept signed dimensionless beta values u and v in (-1,1), compute u'=(u+v)/(1+uv), and label the output as a fraction of c. Alternatively change the input contract to physical velocities and retain uv/c², while explicitly specifying c and output units. The honest label should state collinear one-dimensional relativistic velocity composition, not a general frame-relative velocity calculator.

• The stated inputs are fractions of c, but the formula u'=(u+v)/(1+uv/c²) is dimensionally correct only when u and v are velocities in physical units such as m/s. For dimensionless fractions beta_u=u/c and beta_v=v/c, the formula must be beta'=(beta_u+beta_v)/(1+beta_u beta_v).
• The phrase two frames moving relative to each other is ambiguous: plus-sign velocity composition is appropriate for successive collinear boosts with a specified sign convention, while a direct frame-coordinate velocity transformation commonly uses (u-v)/(1-uv/c²).
• The formula requires explicitly stated one-dimensional, collinear motion and signed velocities; arbitrary vector velocities are not supported by this scalar expression.

Units and conventions

• For the supplied input contract, u and v are dimensionless signed fractions of c, so c cancels and must not appear in the denominator; output u' is also a signed fraction of c.
• If the implementation instead accepts velocities in m/s, c must be supplied numerically in matching units, typically c=299792458 m/s, and the stated uv/c² formula is then dimensionally valid.
• Inputs should normally satisfy |u|<1 and |v|<1 when expressed as fractions of c; the sign indicates the collinear direction.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "u": 0.6,
    "v": 0.5,
    "units": "fractions_of_c"
  },
  "expected_outputs": {
    "u_prime": 0.8461538462,
    "u_prime_exact": "11/13",
    "units": "fraction_of_c"
  },
  "working": "u'=(u+v)/(1+uv)=(0.6+0.5)/(1+(0.6)(0.5))=1.1/(1+0.3)=1.1/1.3=11/13=0.8461538462."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The formula returns an undefined 0/0 result at u=1, v=-1 unless the input is rejected. It also produces a superluminal numerical result for an input just beyond the physical validity boundary, u=0.5 and v=1.001, contrary to the stated no-superluminal-result behavior unless validation rejects that input.

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