Stefan–Boltzmann law

E32546

The Stefan–Boltzmann law is a fundamental principle of thermal radiation stating that the total energy radiated per unit surface area of a black body is proportional to the fourth power of its absolute temperature.

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Statements (48)

Predicate Object
instanceOf physical law
radiation law
appliesTo ideal black body
opaque, diffuse, gray surfaces with modified emissivity
approximateValueOfStefanBoltzmannConstant 5.670374419×10^−8 W⋅m^−2⋅K^−4
assumes surface is a perfect black body with emissivity equal to 1
category laws of thermodynamics and statistical mechanics
dependsOn absolute temperature in kelvins
derivationYear 1884
derivedBy Ludwig Boltzmann
derivedFrom Planck radiation law
surface form: Planck’s law of black-body radiation

thermodynamics of electromagnetic radiation
describes total radiant heat power emitted per unit area of a black body
dimensionOfStefanBoltzmannConstant power per area per temperature to the fourth power
emissivityRange 0 to 1
field astrophysics
statistical mechanics
thermal radiation
thermodynamics
generalization radiant exitance of a real surface is M = ε σ T^4
includesParameter emissivity
isIntegralOver Planck spectral radiance over all wavelengths
all solid angles of emission
mathematicalForm j* = σ T^4
namedAfter Josef Stefan
Ludwig Boltzmann
proportionalTo fourth power of absolute temperature
proposedBy Josef Stefan
relatedTo Kirchhoff's law of thermal radiation
surface form: Kirchhoff’s law of thermal radiation

Planck radiation law
surface form: Planck’s law

Wien displacement law
surface form: Wien’s displacement law

black-body radiation
SIUnitOfStefanBoltzmannConstant watt per square metre per kelvin to the fourth power
states the total energy radiated per unit surface area of a black body is proportional to the fourth power of its absolute temperature
symbolOfRadiantExitance j*
symbolOfStefanBoltzmannConstant σ
symbolOfTemperature T
usedFor calculating radiative heat transfer
climate modeling
estimating luminosity of stars
relating stellar radius, temperature and luminosity
thermal engineering
usedIn design of furnaces and radiative heaters
planetary energy balance models
radiative heat transfer calculations between surfaces
remote sensing of surface temperatures
validFor thermal equilibrium
yearProposed 1879

Referenced by (6)

Full triples — surface form annotated when it differs from this entity's canonical label.

Josef Stefan formulated Stefan–Boltzmann law
Josef Stefan hasStefanBoltzmannLawNamedAfter Stefan–Boltzmann law
Josef Stefan knownFor Stefan–Boltzmann law
Planck radiation law relatedTo Stefan–Boltzmann law
Wien displacement law relatedTo Stefan–Boltzmann law