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CODATA Fundamental Physical Constants Reference Oracle

Returns exact NIST/CODATA fundamental physical constants (speed of light, Planck constant, gravitational constant, Boltzmann, Avogadro, elementary charge).

Call it (no API key)

GET https://api.agentdatahub.de/api/v1/call/physics-fundamental-constants?compact=1

Full metadata: without compact=1 · Markdown: format=llm · Only some fields: add &fields=a,b.c · MCP: tool call_api with {"apiId":"physics-fundamental-constants"}

Parameters

None.

Example response (live, compact)

{
  "apiId": "physics-fundamental-constants",
  "data_freshness": "cached",
  "data": {
    "standard": "NIST CODATA Internationally Recommended Values",
    "constants": {
      "speed_of_light_in_vacuum_c": {
        "value": 299792458,
        "unit": "m s^-1",
        "exact": true
      },
      "planck_constant_h": {
        "value": 6.62607015e-34,
        "unit": "J Hz^-1",
        "exact": true
      },
      "reduced_planck_constant_hbar": {
        "value": 1.054571817e-34,
        "unit": "J s",
        "exact": false
      },
      "newtonian_constant_of_gravitation_G": {
        "value": 6.6743e-11,
        "unit": "m^3 kg^-1 s^-2",
        "exact": false
      },
      "elementary_charge_e": {
        "value": 1.602176634e-19,
        "unit": "C",
        "exact": true
      },
      "boltzmann_constant_k": {
        "value": 1.380649e-23,
        "unit": "J K^-1",
        "exact": true
      },
      "avogadro_constant_NA": {
        "value": 6.02214076e+23,
        "unit": "mol^-1",
        "exact": true
      },
      "molar_gas_constant_R": {
        "value": 8.314462618,
        "unit": "J mol^-1 K^-1",
        "exact": true
      },
      "stefan_boltzmann_constant_sigma": {
        "value": 5.670374419e-8,
        "unit": "W m^-2 K^-4",
        "exact": false
      },
      "electron_mass_me": {
        "value": 9.1093837015e-31,
        "unit": "kg",
        "exact": false
      },
      "proton_mass_mp": {
        "value": 1.67262192369e-27,
        "unit": "kg",
        "exact": false
      },
      "standard_acceleration_of_gravity_g0": {
        "value": 9.80665,
        "unit": "m s^-2",
        "exact": true
      }
    }
  },
  "source": "100% Platform Deterministic Compute / Reference Engine",
  "license": "Public Domain (NIST CODATA)"
}

Source & license