\ phyconsts.4th
\
\ Handy definitions for Forth desktop environment
\
\ References:
\   1. https://physics.nist.gov/cuu/Constants/index.html
\
\ Requires:
\   ans-words.4th
\
\ Revisions:
\   2020-10-06  km  updated for 2019 redefinition of S.I. base units 
\   2023-12-04  km  further updates for m_e, m_p, eps0, alpha^-1,
\                   J/ev, kg/amu; added mu0; correct units for dnu_Cs.

BASE @
DECIMAL

[undefined]  PI [IF] -1e facos fconstant  pi [THEN]
[undefined] 2PI [IF] pi 2e f*  fconstant  2pi [THEN]

\ Physical Constants

    9192631770e  fconstant  dnu_Cs \ hyperfine interval in Cs133 in Hz (exact)
     299792458e  fconstant  c	  \ speed of light in m/s  (exact)
 6.62607015e-34  fconstant  h     \ Planck's constant in J*s (exact)
h 2pi f/         fconstant  hbar  \ 
1.602176634e-19  fconstant  e     \ elementary charge in C  (exact)
1.380649e-23     fconstant  kB    \ Boltzmann's constant in J/K (exact)
6.02214076e23    fconstant  N_A   \ Avogadro constant mol^-1  (exact)

\ Measured Constants
9.1093837015e-31  fconstant  m_e   \ electron mass in kg
1.67262192369e-27 fconstant  m_p   \ proton mass in kg
8.8541878128e-12  fconstant  eps0  \ vacuum electric permittivity in F/m
1.25663706212e-6  fconstant  mu0   \ vacuum magnetic permeability in N/A^2

\ Derived Constants
137.035999084e   fconstant  alpha^-1  \ inverse fine structure constant

\ Unit Conversions
1.602176634e-19   fconstant  J/eV     \ electron volts -> Joules (exact)
1.66053906660e-27 fconstant  kg/amu   \ atomic mass unit -> kilograms
219474.6314e      fconstant  cm^-1/Eh \ Hartree to wavenumber conversion
0.5291772083e     fconstant  A/a0     \ Bohr radii to Angstroms conversion

0 [IF]
.( Defined FCONSTANTs [physical constants in MKS units]: ) CR CR
.(        pi ) CR
.(       2pi ) CR
.(    dnu_Cs     hyperfine transition frequency of Cs-133 [exact]) CR
.(         c     speed of light [exact]) CR
.(         h     Planck's constant [exact]) CR
.(      hbar ) CR
.(         e     elementary charge [exact]) CR
.(        kB     Boltzmann's constant [exact]) CR
.(       N_A     Avogadro constant [exact]) CR
.(       m_e     electron mass ) CR
.(       m_p     proton mass ) CR
.(      eps0     permitivitty of free space ) CR
.(  alpha^-1     inverse fine structure constant ) CR
CR
.( Conversions between units: ) CR CR
.(      J/eV     eV -> J ) CR
.(    kg/amu     amu -> kg ) CR
.(  cm^-1/Eh     Hartree -> wavenumber ) CR
.(      A/a0     Bohr radius -> Angstroms ) CR
CR CR
[THEN]

BASE !

