diff options
Diffstat (limited to 'lisp/calc')
| -rw-r--r-- | lisp/calc/calc-units.el | 41 |
1 files changed, 22 insertions, 19 deletions
diff --git a/lisp/calc/calc-units.el b/lisp/calc/calc-units.el index ab76ded8186..17d16acee0e 100644 --- a/lisp/calc/calc-units.el +++ b/lisp/calc/calc-units.el @@ -46,6 +46,9 @@ ;; CODATA values updated February 2016, using 2014 adjustment ;; http://arxiv.org/pdf/1507.07956.pdf +;; Updated November 2018 for the redefinition of the SI +;; https://www.bipm.org/utils/en/pdf/CGPM/Draft-Resolution-A-EN.pdf + (defvar math-standard-units '( ;; Length ( m nil "*Meter" ) @@ -118,7 +121,7 @@ ( mph "mi/hr" "*Miles per hour" ) ( kph "km/hr" "Kilometers per hour" ) ( knot "nmi/hr" "Knot" ) - ( c "299792458 m/s" "Speed of light" ) ;;; CODATA + ( c "299792458 m/s" "Speed of light" ) ;; SI definition ;; Acceleration ( ga "980665*10^(-5) m/s^2" "*\"g\" acceleration" nil @@ -207,8 +210,8 @@ ( C "A s" "Coulomb" ) ( Fdy "ech Nav" "Faraday" ) ( e "ech" "Elementary charge" ) - ( ech "1.6021766208*10^(-19) C" "Elementary charge" nil - "1.6021766208 10^-19 C (*)") ;;(approx) CODATA + ( ech "1.602176634*10^(-19) C" "Elementary charge" nil + "1.602176634 10^-19 C") ;; SI definition ( V "W/A" "Volt" ) ( ohm "V/A" "Ohm" ) ( Ω "ohm" "Ohm" ) @@ -256,18 +259,21 @@ ( sr nil "*Steradian" ) ;; Other physical quantities - ;; The values are from CODATA, and are approximate. - ( h "6.626070040*10^(-34) J s" "*Planck's constant" nil - "6.626070040 10^-34 J s (*)") + ;; Unless otherwise mentioned, the values are from CODATA, + ;; and are approximate. + ( h "6.62607015*10^(-34) J s" "*Planck's constant" nil + "6.62607015 10^-34 J s") ;; SI definition ( hbar "h / (2 pi)" "Planck's constant" ) ;; Exact - ( mu0 "4 pi 10^(-7) H/m" "Permeability of vacuum") ;; Exact - ( μ0 "mu0" "Permeability of vacuum") ;; Exact - ( eps0 "1 / (mu0 c^2)" "Permittivity of vacuum" ) + ;; After the 2018 SI redefinition, eps0 and mu0 are measured quantities, + ;; and mu0 no longer has the previous exact value of 4 pi 10^(-7) H/m. + ( eps0 "ech^2 / (2 alpha h c)" "Permittivity of vacuum" ) ( ε0 "eps0" "Permittivity of vacuum" ) + ( mu0 "1 / (eps0 c^2)" "Permeability of vacuum") ;; Exact + ( μ0 "mu0" "Permeability of vacuum") ;; Exact ( G "6.67408*10^(-11) m^3/(kg s^2)" "Gravitational constant" nil "6.67408 10^-11 m^3/(kg s^2) (*)") - ( Nav "6.022140857*10^(23) / mol" "Avogadro's constant" nil - "6.022140857 10^23 / mol (*)") + ( Nav "6.02214076*10^(23) / mol" "Avogadro's constant" nil + "6.02214076 10^23 / mol") ;; SI definition ( me "9.10938356*10^(-31) kg" "Electron rest mass" nil "9.10938356 10^-31 kg (*)") ( mp "1.672621898*10^(-27) kg" "Proton rest mass" nil @@ -280,12 +286,10 @@ "1.883531594 10^-28 kg (*)") ( Ryd "10973731.568508 /m" "Rydberg's constant" nil "10973731.568508 /m (*)") - ( k "1.38064852*10^(-23) J/K" "Boltzmann's constant" nil - "1.38064852 10^-23 J/K (*)") - ( sigma "5.670367*10^(-8) W/(m^2 K^4)" "Stefan-Boltzmann constant" nil - "5.670367 10^-8 W/(m^2 K^4) (*)") - ( σ "sigma" "Stefan-Boltzmann constant" nil - "5.670367 10^-8 W/(m^2 K^4) (*)") + ( k "1.380649*10^(-23) J/K" "Boltzmann's constant" nil + "1.380649 10^-23 J/K") ;; SI definition + ( sigma "2 pi^5 k^4 / (15 h^3 c^2)" "Stefan-Boltzmann constant") + ( σ "sigma" "Stefan-Boltzmann constant") ( alpha "7.2973525664*10^(-3)" "Fine structure constant" nil "7.2973525664 10^-3 (*)") ( α "alpha" "Fine structure constant" nil @@ -298,8 +302,7 @@ "-928.4764620 10^-26 J/T (*)") ( mup "1.4106067873*10^(-26) J/T" "Proton magnetic moment" nil "1.4106067873 10^-26 J/T (*)") - ( R0 "8.3144598 J/(mol K)" "Molar gas constant" nil - "8.3144598 J/(mol K) (*)") + ( R0 "Nav k" "Molar gas constant") ;; Exact ( V0 "22.710947*10^(-3) m^3/mol" "Standard volume of ideal gas" nil "22.710947 10^-3 m^3/mol (*)") ;; Logarithmic units |