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| 1 | +module Constants |
| 2 | + |
| 3 | +import ..DEFAULT_QUANTITY_TYPE |
| 4 | +import ..Quantity |
| 5 | +import ..Units as U |
| 6 | +import ..Units: _add_prefixes |
| 7 | + |
| 8 | +const _CONSTANT_SYMBOLS = Symbol[] |
| 9 | +const _CONSTANT_VALUES = DEFAULT_QUANTITY_TYPE[] |
| 10 | + |
| 11 | +macro register_constant(name, value) |
| 12 | + return esc(_register_constant(name, value)) |
| 13 | +end |
| 14 | + |
| 15 | +macro add_prefixes(base_unit, prefixes) |
| 16 | + @assert prefixes.head == :tuple |
| 17 | + return esc(_add_prefixes(base_unit, prefixes.args, _register_constant)) |
| 18 | +end |
| 19 | + |
| 20 | +function _register_constant(name::Symbol, value) |
| 21 | + s = string(name) |
| 22 | + return quote |
| 23 | + const $name = $value |
| 24 | + push!(_CONSTANT_SYMBOLS, Symbol($s)) |
| 25 | + push!(_CONSTANT_VALUES, $name) |
| 26 | + end |
| 27 | +end |
| 28 | + |
| 29 | +# Source: http://physics.nist.gov/constants (2018) |
| 30 | + |
| 31 | +# Exact, base: |
| 32 | +@register_constant c 299792458 * U.m/U.s |
| 33 | +@register_constant h 6.62607015e-34 * U.J/U.Hz |
| 34 | +@register_constant hbar h / (2π) |
| 35 | +@register_constant e 1.602176634e-19 * U.C |
| 36 | +@register_constant k_B 1.380649e-23 * U.J/U.K |
| 37 | +@register_constant N_A 6.02214076e+23 / U.mol |
| 38 | + |
| 39 | +@doc( |
| 40 | + "Speed of light in a vacuum. Standard.", |
| 41 | + c, |
| 42 | +) |
| 43 | +@doc( |
| 44 | + "Planck constant. Standard.", |
| 45 | + h, |
| 46 | +) |
| 47 | +@doc( |
| 48 | + "Reduced Planck constant (h/2π). Standard.", |
| 49 | + hbar, |
| 50 | +) |
| 51 | +@doc( |
| 52 | + "Elementary charge. Standard.", |
| 53 | + e, |
| 54 | +) |
| 55 | +@doc( |
| 56 | + "Boltzmann constant. Standard.", |
| 57 | + k_B, |
| 58 | +) |
| 59 | +@doc( |
| 60 | + "Avogadro constant. Standard.", |
| 61 | + N_A, |
| 62 | +) |
| 63 | + |
| 64 | +# Exact, derived: |
| 65 | +@register_constant eV e * U.J/U.C |
| 66 | +@register_constant R N_A * k_B |
| 67 | +@register_constant F N_A * e |
| 68 | +@register_constant sigma_sb (π^2/60) * k_B^4/(hbar^3 * c^2) |
| 69 | + |
| 70 | +@add_prefixes eV (m, k, M, G, T) |
| 71 | + |
| 72 | +@doc( |
| 73 | + "Electron volt. Standard.", |
| 74 | + eV, |
| 75 | +) |
| 76 | +@doc( |
| 77 | + "Molar gas constant. Standard.", |
| 78 | + R, |
| 79 | +) |
| 80 | +@doc( |
| 81 | + "Faraday constant. Standard.", |
| 82 | + F, |
| 83 | +) |
| 84 | +@doc( |
| 85 | + "Stefan-Boltzmann constant. Standard.", |
| 86 | + sigma_sb, |
| 87 | +) |
| 88 | + |
| 89 | +# Measured |
| 90 | +@register_constant alpha DEFAULT_QUANTITY_TYPE(7.2973525693e-3) |
| 91 | +@register_constant u 1.66053906660e-27 * U.kg |
| 92 | +@register_constant G 6.67430e-11 * U.m^3 / (U.kg * U.s^2) |
| 93 | +@register_constant mu_0 4π * alpha * hbar / (e^2 * c) |
| 94 | +@register_constant eps_0 8.8541878128e-12 * U.F/U.m |
| 95 | +@register_constant m_e 9.1093837015e-31 * U.kg |
| 96 | +@register_constant m_p 1.67262192369e-27 * U.kg |
| 97 | +@register_constant m_n 1.67492749804e-27 * U.kg |
| 98 | +@register_constant a_0 hbar/(m_e * c * alpha) |
| 99 | +@register_constant k_e 1/(4π * eps_0) |
| 100 | +@register_constant Ryd alpha^2 * m_e * c^2 / (2 * h) |
| 101 | + |
| 102 | +@doc( |
| 103 | + "Fine-structure constant. Measured.", |
| 104 | + alpha, |
| 105 | +) |
| 106 | +@doc( |
| 107 | + "Atomic mass unit (1/12th the mass of Carbon-12). Measured.", |
| 108 | + u, |
| 109 | +) |
| 110 | +@doc( |
| 111 | + "Newtonian constant of gravitation. Measured.", |
| 112 | + G, |
| 113 | +) |
| 114 | +@doc( |
| 115 | + "Vacuum magnetic permeability. Measured.", |
| 116 | + mu_0, |
| 117 | +) |
| 118 | +@doc( |
| 119 | + "Vacuum electric permittivity. Measured.", |
| 120 | + eps_0, |
| 121 | +) |
| 122 | +@doc( |
| 123 | + "Electron mass. Measured.", |
| 124 | + m_e, |
| 125 | +) |
| 126 | +@doc( |
| 127 | + "Proton mass. Measured.", |
| 128 | + m_p, |
| 129 | +) |
| 130 | +@doc( |
| 131 | + "Neutron mass. Measured.", |
| 132 | + m_n, |
| 133 | +) |
| 134 | +@doc( |
| 135 | + "Bohr radius. Measured.", |
| 136 | + a_0, |
| 137 | +) |
| 138 | +@doc( |
| 139 | + "Coulomb constant (Note: SI units only!). Measured.", |
| 140 | + k_e, |
| 141 | +) |
| 142 | +@doc( |
| 143 | + "Rydberg frequency. Measured.", |
| 144 | + Ryd, |
| 145 | +) |
| 146 | + |
| 147 | +# Astro constants. |
| 148 | +# Source: https://arxiv.org/abs/1510.07674 |
| 149 | + |
| 150 | +@register_constant M_earth 5.97216787e+24 * U.kg |
| 151 | +@register_constant M_sun 1.98840987e+30 * U.kg |
| 152 | +@register_constant M_jup 1.8981246e+27 * U.kg |
| 153 | +@register_constant R_earth 6.3781e+6 * U.m |
| 154 | +@register_constant R_jup 7.1492e+7 * U.m |
| 155 | +@register_constant R_sun 6.957e+8 * U.m |
| 156 | +@register_constant L_sun 3.828e+26 * U.W |
| 157 | +@register_constant L_bol0 3.0128e+28 * U.W |
| 158 | +@register_constant sigma_T 6.6524587321e-29 * U.m^2 |
| 159 | +@register_constant au 149597870700 * U.m |
| 160 | +@register_constant pc (648000/π) * au |
| 161 | +@register_constant ly c * U.yr |
| 162 | +@register_constant atm 101325 * U.Pa |
| 163 | + |
| 164 | +@add_prefixes pc (k, M, G) |
| 165 | + |
| 166 | +@doc( |
| 167 | + "Earth mass. Measured.", |
| 168 | + M_earth, |
| 169 | +) |
| 170 | +@doc( |
| 171 | + "Solar mass. Measured.", |
| 172 | + M_sun, |
| 173 | +) |
| 174 | +@doc( |
| 175 | + "Jupiter mass. Measured.", |
| 176 | + M_jup, |
| 177 | +) |
| 178 | +@doc( |
| 179 | + "Nominal Earth equatorial radius. Standard.", |
| 180 | + R_earth, |
| 181 | +) |
| 182 | +@doc( |
| 183 | + "Nominal Jupiter equatorial radius. Standard.", |
| 184 | + R_jup, |
| 185 | +) |
| 186 | +@doc( |
| 187 | + "Nominal solar radius. Standard.", |
| 188 | + R_sun, |
| 189 | +) |
| 190 | +@doc( |
| 191 | + "Nominal solar luminosity. Standard.", |
| 192 | + L_sun, |
| 193 | +) |
| 194 | +@doc( |
| 195 | + "Standard luminosity at absolute bolometric magnitude 0. Standard.", |
| 196 | + L_bol0, |
| 197 | +) |
| 198 | +@doc( |
| 199 | + "Thomson scattering cross-section. Measured.", |
| 200 | + sigma_T, |
| 201 | +) |
| 202 | +@doc( |
| 203 | + "Astronomical unit. Standard.", |
| 204 | + au, |
| 205 | +) |
| 206 | +@doc( |
| 207 | + "Parsec. Standard.", |
| 208 | + pc, |
| 209 | +) |
| 210 | +@doc( |
| 211 | + "Light year. Standard.", |
| 212 | + ly, |
| 213 | +) |
| 214 | +@doc( |
| 215 | + "Standard atmosphere. Standard.", |
| 216 | + atm, |
| 217 | +) |
| 218 | + |
| 219 | +"""A tuple of all possible constants.""" |
| 220 | +const CONSTANT_SYMBOLS = Tuple(_CONSTANT_SYMBOLS) |
| 221 | +const CONSTANT_VALUES = Tuple(_CONSTANT_VALUES) |
| 222 | +const CONSTANT_MAPPING = NamedTuple([s => i for (i, s) in enumerate(CONSTANT_SYMBOLS)]) |
| 223 | + |
| 224 | +end |
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