Subject: 30.0.50; Update Calc units table

From: Ulrich Müller <[email-masked]>
Date: Wed, 29 Nov 2023 11:10:08 +0100

The patch below updates the Calc units table.

The latest CODATA adjustment was for 2018. Not sure if we could instead
wait for publication of the 2022 adjustment; it may be too late to make
it for the 30.1 release. (If it would have a similar delay as for 2018,
then the 2022 values would be published in 2025.)

I've also collected the SI defining constants in their own category,
and updated some spellings (because BIPM, CODATA, and NIST all say
"Planck constant", "Boltzmann constant", etc.).

Please review.

>From 62a1ad31cf89d6efdf1579131ef0744c8493a357 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ulrich=20M=C3=BCller?= <[email-masked]>
Date: Wed, 29 Nov 2023 10:24:06 +0100
Subject: [PATCH] Update Calc units table

* lisp/calc/calc-units.el (math-standard-units): Update to 2018
CODATA adjustment. Use exact value for V0. Update some spellings,
e.g. "Planck constant" instead of "Planck's constant".
---
 lisp/calc/calc-units.el | 93 ++++++++++++++++++++++-------------------
 1 file changed, 49 insertions(+), 44 deletions(-)

diff --git a/lisp/calc/calc-units.el b/lisp/calc/calc-units.el
index f20e5801a01..2acc98ed384 100644
--- a/lisp/calc/calc-units.el
+++ b/lisp/calc/calc-units.el
@@ -43,12 +43,13 @@
 ;;;             Measures, by François Cardarelli)
 ;;; All conversions are exact unless otherwise noted.
 
-;; CODATA values updated February 2016, using 2014 adjustment
-;; https://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
 
+;; CODATA values last updated November 2023, using 2018 adjustment:
+;; E. Tiesinga, P. J. Mohr, D. B. Newell, and B. N. Taylor,
+;; Rev. Mod. Phys. 93, 025010 (2021)
+
 (defvar math-standard-units
   '( ;; Length
     ( m       nil                    "*Meter" )
@@ -122,7 +123,6 @@ math-standard-units
     ( mph     "mi/hr"                "*Miles per hour" )
     ( kph     "km/hr"                "Kilometers per hour" )
     ( knot    "nmi/hr"               "Knot" )
-    ( c       "299792458 m/s"        "Speed of light" ) ;; SI definition
 
     ;; Acceleration
     ( ga      "980665*10^(-5) m/s^2" "*\"g\" acceleration" nil
@@ -143,8 +143,8 @@ math-standard-units
               "31.10347680 g") ;; ESUWM, 1/12 exact value for lbt
     ( ct      "(2/10) g"             "Carat" nil
               "0.2 g") ;; ESUWM
-    ( u       "1.660539040*10^(-27) kg"    "Unified atomic mass" nil
-              "1.660539040 10^-27 kg (*)");;(approx) CODATA
+    ( u       "1.66053906660*10^(-27) kg"    "Unified atomic mass" nil
+              "1.66053906660 10^-27 kg (*)") ;; (approx) CODATA
 
     ;; Force
     ( N       "m kg/s^2"             "*Newton" )
@@ -210,9 +210,6 @@ math-standard-units
     ( A       nil                     "*Ampere" )
     ( C       "A s"                   "Coulomb" )
     ( Fdy     "ech Nav"               "Faraday" )
-    ( e       "ech"                   "Elementary charge" )
-    ( 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" )
@@ -259,53 +256,61 @@ math-standard-units
     ;; Solid angle
     ( sr      nil                      "*Steradian" )
 
+    ;; Constants defining the International System of Units (SI)
+    ( c       "299792458 m/s"               "*Speed of light" )
+    ( h       "6.62607015*10^(-34) J s"     "Planck constant" nil
+              "6.62607015 10^-34 J s")
+    ( ech     "1.602176634*10^(-19) C"      "Elementary charge" nil
+              "1.602176634 10^-19 C")
+    ( e       "ech"                         "Elementary charge" nil
+              "1.602176634 10^-19 C")
+    ( k       "1.380649*10^(-23) J/K"       "Boltzmann constant" nil
+              "1.380649 10^-23 J/K")
+    ( Nav     "6.02214076*10^(23) / mol"    "Avogadro constant" nil
+              "6.02214076 10^23 / mol")
+
     ;; Other physical quantities
     ;; 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
+    ( hbar    "h / (2 pi)"                  "*Reduced Planck constant" )
     ;; 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")
     ( μ0      "mu0"                         "Permeability of vacuum")
-    ( G       "6.67408*10^(-11) m^3/(kg s^2)"    "Gravitational constant" nil
-              "6.67408 10^-11 m^3/(kg s^2) (*)")
-    ( 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
-              "1.672621898 10^-27 kg (*)")
-    ( mn      "1.674927471*10^(-27) kg"     "Neutron rest mass" nil
-              "1.674927471 10^-27 kg (*)")
-    ( mmu     "1.883531594*10^(-28) kg"      "Muon rest mass" nil
-              "1.883531594 10^-28 kg (*)")
+    ( G       "6.67430*10^(-11) m^3/(kg s^2)"    "Gravitational constant" nil
+              "6.67430 10^-11 m^3/(kg s^2) (*)")
+    ( me      "9.1093837015*10^(-31) kg"    "Electron rest mass" nil
+              "9.1093837015 10^-31 kg (*)")
+    ( mp      "1.67262192369*10^(-27) kg"   "Proton rest mass" nil
+              "1.67262192369 10^-27 kg (*)")
+    ( mn      "1.67492749804*10^(-27) kg"   "Neutron rest mass" nil
+              "1.67492749804 10^-27 kg (*)")
+    ( mmu     "1.883531627*10^(-28) kg"     "Muon rest mass" nil
+              "1.883531627 10^-28 kg (*)")
     ( mμ      "mmu"                         "Muon rest mass" nil
-              "1.883531594 10^-28 kg (*)")
-    ( Ryd     "10973731.568508 /m"          "Rydberg's constant" nil
-              "10973731.568508 /m (*)")
-    ( k       "1.380649*10^(-23) J/K"       "Boltzmann's constant" nil
-              "1.380649 10^-23 J/K")        ;; SI definition
+              "1.883531627 10^-28 kg (*)")
+    ( Ryd     "10973731.568160 /m"          "Rydberg constant" nil
+              "10973731.568160 /m (*)")
     ( 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
-              "7.2973525664 10^-3 (*)")
-    ( muB     "927.4009994*10^(-26) J/T"     "Bohr magneton" nil
-              "927.4009994 10^-26 J/T (*)")
-    ( muN     "5.050783699*10^(-27) J/T"     "Nuclear magneton" nil
-              "5.050783699 10^-27 J/T (*)")
-    ( mue     "-928.4764620*10^(-26) J/T"    "Electron magnetic moment" 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      "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 (*)")
+    ( alpha   "7.2973525693*10^(-3)"        "Fine structure constant" nil
+              "7.2973525693 10^-3 (*)")
+    ( α       "alpha"                       "Fine structure constant" nil
+              "7.2973525693 10^-3 (*)")
+    ( muB     "9.2740100783*10^(-24) J/T"   "Bohr magneton" nil
+              "9.2740100783 10^-24 J/T (*)")
+    ( muN     "5.0507837461*10^(-27) J/T"   "Nuclear magneton" nil
+              "5.0507837461 10^-27 J/T (*)")
+    ( mue     "−9.2847647043*10^(-24) J/T"  "Electron magnetic moment" nil
+              "-9.2847647043 10^-24 J/T (*)")
+    ( mup     "1.41060679736*10^(-26) J/T"  "Proton magnetic moment" nil
+              "1.41060679736 10^-26 J/T (*)")
+    ( R0      "Nav k"                       "Molar gas constant" )
+    ( V0      "R0 273.15 K / 10^5 Pa"       "Standard volume of ideal gas" )
+              ;; IUPAC 1982 standard temperature and pressure
+
     ;; Logarithmic units
     ( Np      nil    "*Neper")
     ( dB      "(ln(10)/20) Np" "decibel"))
-- 
2.43.0