: Np ( n -- neper ) { } { } <dimensioned> ;
: B ( n -- bel ) 1.151292546497023 * Np ;
: eV ( n -- electronvolt ) 1.60218e-19 * J ;
-: u ( n -- unified-atomic-mass-unit ) 1.66054e-27 * kg ;
+: u ( n -- unified-atomic-mass-unit ) 1.660539040e-27 * kg ;
! au has error of 30m, according to wikipedia
: au ( n -- astronomical-unit ) 149597870691 * m ;