GNU bug report logs - #33412
27.0.50; [PATCH] Update the calc units table

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Ulrich Müller <ulm <at> gentoo.org>
To: bug-gnu-emacs <at> gnu.org
Subject: 27.0.50; [PATCH] Update the calc units table
Date: Sat, 17 Nov 2018 12:00:28 +0100

From 9d39d385708c4f045d63c5169133234ee9480c45 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ulrich=20M=C3=BCller?= <ulm <at> gentoo.org>
Date: Sat, 17 Nov 2018 11:43:06 +0100
Subject: [PATCH] Update the calc units table

On 2018-11-16, the 26th meeting of the General Conference on Weights
and Measures (CGPM) has redefined the International System of Units by
adopting fixed values for the Planck constant, the elementary charge,
the Boltzmann constant, and the Avogadro constant:
https://www.bipm.org/utils/en/pdf/CGPM/Draft-Resolution-A-EN.pdf
* lisp/calc/calc-units.el (math-standard-units): Update according
to redefinition of the SI in 2018.
---
 lisp/calc/calc-units.el | 41 ++++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 19 deletions(-)

diff --git a/lisp/calc/calc-units.el b/lisp/calc/calc-units.el
index ab76ded818..17d16acee0 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
-- 
2.19.1

Message #10 received at 33412-done <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Ulrich Müller <ulm <at> gentoo.org>
Cc: 33412-done <at> debbugs.gnu.org
Subject: Re: 27.0.50; [PATCH] Update the calc units table
Date: Mon, 19 Nov 2018 07:35:22 -0800

Thanks, I installed the patch.

Message #13 received at 33412-done <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Ulrich Müller <ulm <at> gentoo.org>
Cc: 33412-done <at> debbugs.gnu.org
Subject: Re: bug#33412: 27.0.50; [PATCH] Update the calc units table
Date: Sat, 24 Nov 2018 10:10:56 +0200

> From: Ulrich Müller <ulm <at> gentoo.org>
> Date: Sat, 17 Nov 2018 12:00:28 +0100
> 
> >From 9d39d385708c4f045d63c5169133234ee9480c45 Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?Ulrich=20M=C3=BCller?= <ulm <at> gentoo.org>
> Date: Sat, 17 Nov 2018 11:43:06 +0100
> Subject: [PATCH] Update the calc units table
> 
> On 2018-11-16, the 26th meeting of the General Conference on Weights
> and Measures (CGPM) has redefined the International System of Units by
> adopting fixed values for the Planck constant, the elementary charge,
> the Boltzmann constant, and the Avogadro constant:
> https://www.bipm.org/utils/en/pdf/CGPM/Draft-Resolution-A-EN.pdf
> * lisp/calc/calc-units.el (math-standard-units): Update according
> to redefinition of the SI in 2018.

Thanks, pushed to the emacs-26 branch.

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