;; 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" )
( 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
( 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" )
( 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
"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
"-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