# Physics Calculators: Blackbody Radiation

> Physics Calculators: Blackbody Radiation is a paid API for AI agents from physics-calc.x402tookit.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-30).

Calculates Wien peak wavelength/frequency, Stefan-Boltzmann radiant exitance, and total radiated power for a blackbody at a given temperature

## Facts

- Endpoint: GET https://physics-calc.x402tookit.com/blackbody?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/physics-calculators-blackbody-radiation-ca4e6dad
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Rtr6KJW3vqiHVWfK_s5Qv

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability physics-calculators-blackbody-radiation-ca4e6dad
```

Example prompt: What is the peak emission wavelength and total radiated power for a blackbody sphere with a radius of 0.696 billion metres at 5778 K, assuming perfect emissivity?

## When to prefer this

Use this endpoint when you need precise blackbody radiation calculations — peak wavelength, peak frequency, spectral band, radiant exitance, or total emitted power — for any object whose temperature is known in kelvin. It is the right choice for astrophysics (stellar spectra), thermal engineering (furnaces, heaters), remote sensing (Earth/atmospheric emission), or any scenario requiring the full set of Wien and Stefan-Boltzmann outputs in a single call.

## Known failure modes

- Temperature below 1 K or above 1×10⁹ K returns a validation error
- Missing required temperatureK parameter returns an error
- Non-numeric input for temperature, area, or radius causes a 400-level error
- Emissivity outside 0–1 range is rejected
- Network or payment (x402) failure results in no response

## How this service works

Blackbody radiation: Wien peak wavelength and frequency, Stefan-Boltzmann power per area, and total power for an area or sphere.

## Output

Returns Wien peak wavelength in metres and nanometres, Wien peak frequency in Hz, the named spectral band of peak emission (e.g. infrared, visible), Stefan-Boltzmann radiant exitance in W/m², optional total radiated power in watts (if area or radius provided), the emissivity used, the Stefan-Boltzmann and Wien displacement constants, and a human-readable summary.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "temperatureK"
     ],
     "properties": {
      "areaM2": {
       "type": "number",
       "description": "Radiating area in m2, for total power"
      },
      "radiusM": {
       "type": "number",
       "description": "Or the radius of a sphere in metres (area = 4 pi r^2)"
      },
      "emissivity": {
       "type": "number",
       "description": "Emissivity 0 to 1 (default 1, an ideal blackbody)"
      },
      "temperatureK": {
       "type": "number",
       "description": "Surface temperature in kelvin, 1 to 1e9"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "asOf": {
       "type": [
        "null",
        "string"
       ]
      },
      "sigma": {
       "type": [
        "null",
        "number"
       ]
      },
      "wienB": {
       "type": [
        "null",
        "number"
       ]
      },
      "areaM2": {
       "type": [
        "null",
        "number"
       ]
      },
      "source": {
       "type": [
        "null",
        "string"
       ]
      },
      "reasons": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "summary": {
       "type": [
        "null",
        "string"
       ]
      },
      "verdict": {
       "type": [
        "null",
        "string"
       ]
      },
      "degraded": {
       "type": [
        "boolean",
        "null"
       ]
      },
      "peakBand": {
       "type": [
        "null",
        "string"
       ]
      },
      "disclaimer": {
       "type": [
        "null",
        "string"
       ]
      },
      "emissivity": {
       "type": [
        "null",
        "number"
       ]
      },
      "notChecked": {
       "type": [
        "array",
        "null"
       ],
       "items": {
        "type": "string"
       }
      },
      "totalPowerW": {
       "
… (truncated)
```

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