Create physical constants submodule

Author: MilesCranmer

src/DynamicQuantities.jl

@@ -1,5 +1,6 @@
 module DynamicQuantities
 
+export Units, Const
 export Quantity, Dimensions, DimensionError, ustrip, dimension, valid
 export ulength, umass, utime, ucurrent, utemperature, uluminosity, uamount
 export uparse, @u_str
@@ -8,10 +9,10 @@ include("fixed_rational.jl")
 include("types.jl")
 include("utils.jl")
 include("math.jl")
-include("units.jl")
+include("units.jl") # < include("constants.jl")
 
 import Requires: @init, @require
-import .Units: uparse, @u_str
+import .Units: uparse, @u_str, Const
 
 if !isdefined(Base, :get_extension)
     @init @require Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d" include("../ext/DynamicQuantitiesUnitfulExt.jl")

src/constants.jl

@@ -0,0 +1,89 @@
+module Const
+
+import ..@u_str
+import ..@add_prefixes
+
+# Source: http://physics.nist.gov/constants (2018)
+
+# Exact, base:
+"Speed of light in a vacuum. Standard."
+const c = 299792458u"m/s"
+"Planck constant. Standard."
+const h = 6.62607015e−34u"J/Hz"
+"Reduced Planck constant (h/2π). Standard."
+const hbar = h / (2π)
+"Elementary charge. Standard."
+const e = 1.602176634e−19u"C"
+"Boltzmann constant. Standard."
+const k_B = 1.380649e−23u"J/K"
+"Avogadro constant. Standard."
+const N_A = 6.02214076e+23u"mol^-1"
+
+# Exact, derived:
+"Electron volt. Standard."
+const eV = e * u"J/C"
+@add_prefixes eV (m, k, M, G, T)
+"Molar gas constant. Standard."
+const R = N_A * k_B
+"Faraday constant. Standard."
+const F = N_A * e
+"Stefan-Boltzmann constant. Standard."
+const sigma_sb = (π^2/60) * k_B^4/(hbar^3 * c^2)
+
+# Measured
+"Fine-structure constant. Measured."
+const alpha = 7.2973525693e−3
+"Atomic mass unit (1/12th the mass of Carbon-12). Measured."
+const u = 1.66053906660e-27u"kg"
+"Newtonian constant of gravitation. Measured."
+const G = 6.67430e-11u"m^3/(kg*s^2)"
+"Vacuum magnetic permeability. Measured."
+const mu_0 = 4π * alpha * hbar / (e^2 * c)
+"Vacuum electric permittivity. Measured."
+const eps_0 = 8.8541878128e-12u"F/m"
+"Electron mass. Measured."
+const m_e = 9.1093837015e−31u"kg"
+"Proton mass. Measured."
+const m_p = 1.67262192369e−27u"kg"
+"Neutron mass. Measured."
+const m_n = 1.67492749804e-27 kg
+"Bohr radius. Measured."
+const a_0 = hbar/(m_e * c * alpha)
+"Coulomb constant (Note: SI units only!). Measured."
+const k_e = 1/(4π * eps_0)
+"Rydberg frequency. Measured."
+const Ryd = alpha^2 * m_e * c^2 / (2 * h)
+
+
+# Astro constants.
+# Source: https://arxiv.org/abs/1510.07674
+
+"Earth mass. Measured."
+const M_earth = 5.97216787e+24u"kg"
+"Solar mass. Measured."
+const M_sun = 1.98840987e+30u"kg"
+"Jupiter mass. Measured."
+const M_jup = 1.8981246e+27u"kg"
+"Nominal Earth equatorial radius. Standard."
+const R_earth = 6.3781e+6u"m"
+"Nominal Jupiter equatorial radius. Standard."
+const R_jup = 7.1492e+7u"m"
+"Nominal solar radius. Standard."
+const R_sun = 6.957e+8u"m"
+"Nominal solar luminosity. Standard."
+const L_sun = 3.828e+26u"W"
+"Standard luminosity at absolute bolometric magnitude 0. Standard."
+const L_bol0 = 3.0128e+28u"W"
+"Thomson scattering cross-section. Measured."
+const sigma_T = 6.6524587321e-29u"m^2"
+"Astronomical unit. Standard."
+const au = 149597870700u"m"
+"Parsec. Standard."
+const pc = (648000/π) * au
+@add_prefixes pc (k, M, G)
+"Light year. Standard."
+const ly = c * u"yr"
+"Standard atmosphere. Standard."
+const atm = 101325u"Pa"
+
+end

src/units.jl

@@ -17,7 +17,7 @@ end
 function _add_prefixes(base_unit::Symbol, prefixes)
     all_prefixes = (
         f=1e-15, p=1e-12, n=1e-9, μ=1e-6, u=1e-6, m=1e-3, c=1e-2, d=1e-1,
-        k=1e3, M=1e6, G=1e9
+        k=1e3, M=1e6, G=1e9, T=1e12
     )
     expr = Expr(:block)
     for (prefix, value) in zip(keys(all_prefixes), values(all_prefixes))
@@ -145,4 +145,7 @@ macro u_str(s)
     return esc(uparse(s))
 end
 
+include("constants.jl")
+import .Const
+
 end