Malus's Law Polarization Calculator mechanism

Model scope

The single-polarizer formula is standard under its stated physical assumptions. Verdict is NEEDS_REVIEW because the specification simultaneously claims single- and two-polarizer operation without defining the required stack formula or polarization state, and it omits an explicit angle convention and percent-transmission formula.

• I=I0 cos²θ is correct for fully linearly polarized incident light when θ is the angle between the incident polarization direction and the transmission axis of one ideal polarizer.
• The stated single-or-two-polarizer input is ambiguous: a two-polarizer stack requires the relative angle between polarizers and a defined initial polarization state. For an initially polarized beam, sequential transmission is I=I0 cos²(θ1) cos²(θ2−θ1); for unpolarized light, the first ideal polarizer transmits I0/2.
• The percent-transmission output formula is not explicitly stated; it should be 100×I/I0 when I0 is nonzero and the percentage is referenced to the incident intensity.
• The honest label should explicitly state that the formula does not apply directly to unpolarized incident light unless the first-polarizer I0/2 factor is included.

Units and conventions

• I0 and transmitted intensity must use the same intensity units; the test vectors use W/m².
• θ is dimensionless inside the trigonometric function and must be explicitly interpreted as either degrees or radians. The specification does not select one.
• Percent transmission is relative to the supplied incident intensity I0, not relative to an unpolarized-beam convention or a lossless maximum after another polarizer.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "I0_W_per_m2": 100,
    "theta": 0,
    "angle_unit": "degrees"
  },
  "expected_outputs": {
    "transmitted_intensity_W_per_m2": 100,
    "percent_transmission": 100
  },
  "working": "cos(0°)=1; cos²(0°)=1²=1; I=100×1=100 W/m²; percent=100×100/100=100%."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The angle unit is unspecified. The input value 60 yields 25% transmission when interpreted as degrees but 90.70904852632809% when interpreted as radians, so the calculator can return a materially wrong result unless the unit convention is explicit or enforced.

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