correct unit of Stefan-Boltzmann-Constant (#11)

correct unit of Stefan-Boltzmann-Constant
JuliaPhysics · Apr 28, 2019 · b99e9f8 · b99e9f8
2 parents 6e965c2 + 60e4385
commit b99e9f8
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Showing 3 changed files with 6 additions and 4 deletions.
diff --git a/README.md b/README.md
@@ -163,7 +163,7 @@ end
 | `SpeedOfLightInVacuum`                  | `c_0` | 2.99792458e8           | `m s^-1`         |
 | `StandardAccelerationOfGravitation`     | `g_n` | 9.80665                | `m s^-2`         |
 | `StandardAtmosphere`                    | `atm` | 101325.0               | `Pa`             |
-| `StefanBoltzmannConstant`               | `σ`   | 5.670367e-8            | `m^2`            |
+| `StefanBoltzmannConstant`               | `σ`   | 5.670367e-8            | `W m^-2 K^-4`    |
 | `ThomsonCrossSection`                   | `σ_e` | 6.6524587158e-29       | `m^2`            |
 | `WienWavelengthDisplacementLawConstant` | `b`   | 0.0028977729           | `K m`            |
 

diff --git a/src/codata2014.jl b/src/codata2014.jl
@@ -2,7 +2,7 @@ module CODATA2014
 
 using PhysicalConstants, Measurements, Unitful
 
-import Unitful: Ω, A, C, F, J, kg, K, m, mol, N, Pa, s, T
+import Unitful: Ω, A, C, F, J, kg, K, m, mol, N, Pa, s, T, W
 import PhysicalConstants: @constant, @derived_constant
 
 @constant(FineStructureConstant, α, "Fine-structure constant", 7.297_352_5664e-3,
@@ -75,7 +75,7 @@ import PhysicalConstants: @constant, @derived_constant
           BigFloat(10_973_731_568_508)/BigFloat(1_000_000), m^-1,
           6.5e-5, BigFloat(65)/BigFloat(1_000_000), "CODATA 2014")
 @constant(StefanBoltzmannConstant, σ, "Stefan-Boltzmann constant", 5.670_367e-8,
-          BigFloat(5670_367)/BigFloat(100_000_000_000_000), m^2,
+          BigFloat(5670_367)/BigFloat(100_000_000_000_000), W * m^-2 * K^-4,
           1.3e-13, BigFloat(13)/BigFloat(100_000_000_000_000), "CODATA 2014")
 @constant(ThomsonCrossSection, σ_e, "Thomson cross section", 0.665_245_871_58e-28,
           BigFloat(66_524_587_158)/BigFloat(1000_000_000_000_000_000_000_000_000_000_000_000_000),

diff --git a/test/runtests.jl b/test/runtests.jl
@@ -1,7 +1,7 @@
 using PhysicalConstants.CODATA2014, Measurements, Unitful
 using Test
 
-import PhysicalConstants.CODATA2014: α, atm, c_0, e, ε_0, h, ħ, µ_0
+import PhysicalConstants.CODATA2014: α, atm, c_0, e, ε_0, h, ħ, k_B, µ_0, σ
 
 @testset "Base" begin
     @test ustrip(big(h)) == big"6.626070040e-34"
@@ -39,6 +39,8 @@ end
     @test ε_0 ≈ @inferred(1 / (μ_0 * c_0 ^ 2))
     @test @inferred(big(0) + α) == big(α)
     @test @inferred(α * 1.0) == float(α)
+    @test (pi ^ 2 * k_B ^ 4) / (60 * ħ ^ 3 * c_0 ^ 2) ≈
+        σ atol = measurement(σ).val.err * unit(σ)
 end
 
 @testset "Show" begin