Groups > sci.physics.relativity > #593439

Re: Why Does the Metric contain a minus sign?

From	Thomas 'PointedEars' Lahn <PointedEars@web.de>
Newsgroups	sci.physics.relativity
Subject	Re: Why Does the Metric contain a minus sign?
Date	2022-10-14 23:41 +0200
Organization	PointedEars Software (PES)
Message-ID	<2147182.irdbgypaU6@PointedEars.de> (permalink)
References	<8b322777-1913-4360-bce8-555912ea9237n@googlegroups.com> <12100779.O9o76ZdvQC@PointedEars.de> <af9baa6a-a511-42dc-9177-50f641e8e4b1n@googlegroups.com>

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[Quotation trimmed; please read 
<https://www.netmeister.org/news/learn2quote.html>]

George Hammond wrote:

> [George E Hammond, MS physics, Hyannis MA]
> .... Thanks PointedEars for your brilliant pedagogical demonstration of
> the Lorentz transformation.

Thank you very much.  I consider that high praise coming from an MSc in 
Physics as I am only working on my BSc degree in that field.

This also puzzles me, though.  If you are who you say you are, then you 
should know all this.  Moreover, you should know that I have not at all 
demonstrated the Lorentz transformation, but – as I just said – showed a way 
to derive the _Minkowski metric_ (which the Lorentz transformation just 
satisfies as the metric was developed afterwards by Minkowski).

> .... Am I behind the times or something? –

Regarding computing that is apparently so.

> we never used to be able to write "exponents" on USENET instead had to
> write x^2 in ASCII. ....How did you manage to post those algebraic
> equations on sci.physics.relativity ?

Unicode formally exists since 1991, has been having support by operating 
systems for quite some time now, and has official support in NetNews 
messages since 2009 through the requirement of MIME support in RFC 5536 
(current status: Proposed Standard).  7-bit data lines are few and far in-
between now, and even with those MIME allows to encode non-ASCII characters.  
However, even character encodings and sets that predate Unicode, like 
ISO/IEC 8859-1 and Windows-1252 (“ISO-8859-1”) already contain the 
characters “²” and “³”.

In this case in particular the X Keyboard Extension, built-in to the X 
Window System, allowed me to type “^” followed by “2” to type easily the 
Unicode character “²” on GNU+Linux.  There are other ways for other, even 
more widely distributed consumer operating systems.

<https://en.wikipedia.org/wiki/Unicode>
<https://en.wikipedia.org/wiki/ISO/IEC_8859-1>
<https://en.wikipedia.org/wiki/ISO/Windows-1252
<https://en.wikipedia.org/wiki/ISO/X_Keyboard_Extension>

With that said, nowadays there are newsreaders like Mozilla Thunderbird 
which convert some ASCII character sequences, like “^2”, to their Unicode 
equivalent or at least a typographically adequate form, for the display of 
messages.

I have even written a user script to convert some character sequences to 
Unicode characters in Google Groups (which you are using, but I recommend 
against using because it is technically flawed) automagically.

Finally, as Google Groups is a *Web* interface, it should not surprise you 
at all to see Unicode characters being displayed *there* as HTML has had 
official Unicode support since 1999.

PointedEars
-- 
Q: How many theoretical physicists specializing in general relativity
   does it take to change a light bulb?  
A: Two: one to hold the bulb and one to rotate the universe.
(from: WolframAlpha)

Thread

Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-10 09:12 -0700
  Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-10 11:13 -0700
    Re: Why Does the Metric contain a minus sign? Mandy Stabile <alts@ilnnnbsl.ed> - 2022-10-10 18:37 +0000
      Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-10 16:32 -0700
        Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-12 09:26 -0700
          Re: Why Does the Metric contain a minus sign? Athel Cornish-Bowden <acornish@imm.cnrs.fr> - 2022-10-12 19:38 +0200
          Re: Why Does the Metric contain a minus sign? Chip Gabrielli <eici@apeciill.bl> - 2022-10-13 17:17 +0000
          Re: Why Does the Metric contain a minus sign? Woodrow Adessi <reds@odirsodo.er> - 2022-10-13 22:00 +0000
        Re: Why Does the Metric contain a minus sign? nospam@de-ster.demon.nl (J. J. Lodder) - 2022-10-12 21:03 +0200
  Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-13 22:09 +0200
    Re: Why Does the Metric contain a minus sign? Maciej Wozniak <maluwozniak@gmail.com> - 2022-10-13 23:18 -0700
    Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-14 10:25 -0700
      Re: Why Does the Metric contain a minus sign? Woodrow Adessi <reds@odirsodo.er> - 2022-10-14 17:36 +0000
        Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-14 11:23 -0700
          Re: Why Does the Metric contain a minus sign? Woodrow Adessi <reds@odirsodo.er> - 2022-10-14 19:50 +0000
            Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-14 23:55 +0200
              Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag Woodrow Adessi <reds@odirsodo.er> - 2022-10-14 22:03 +0000
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-14 15:45 -0700
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag whodat <whodaat@void.nowgre.com> - 2022-10-14 18:01 -0500
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 02:40 +0200
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag William Stickers <bill.stickers@innocent.com> - 2022-10-17 11:09 +0100
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag whodat <whodaat@void.nowgre.com> - 2022-10-17 07:49 -0500
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag Maciej Wozniak <maluwozniak@gmail.com> - 2022-10-17 08:25 -0700
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-15 12:47 -0700
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-17 01:10 +0200
                Re: the 'PointedEars' Lahn, the braindead uneducated, unskilled and unemployed scumbag whodat <whodaat@void.nowgre.com> - 2022-10-16 22:09 -0500
          Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 00:03 +0200
            Re: Why Does the Metric contain a minus sign? Woodrow Adessi <reds@odirsodo.er> - 2022-10-14 22:06 +0000
        Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-14 23:54 +0200
          Re: Why Does the Metric contain a minus sign? Woodrow Adessi <reds@odirsodo.er> - 2022-10-14 22:18 +0000
            Re: Why Does the Metric contain a minus sign? whodat <whodaat@void.nowgre.com> - 2022-10-14 17:56 -0500
              Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 02:37 +0200
                Re: Why Does the Metric contain a minus sign? whodat <whodaat@void.nowgre.com> - 2022-10-14 21:33 -0500
                Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 20:09 +0200
                Re: Why Does the Metric contain a minus sign? whodat <whodaat@void.nowgre.com> - 2022-10-15 13:25 -0500
                Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-17 00:55 +0200
                Re: Why Does the Metric contain a minus sign? whodat <whodaat@void.nowgre.com> - 2022-10-16 22:02 -0500
                Re: Why Does the Metric contain a minus sign? Joaquin Cuocco <cicu@acacqjuc.co> - 2022-10-17 14:59 +0000
                Re: Why Does the Metric contain a minus sign? Jim Pennino <jimp@gonzo.specsol.net> - 2022-10-17 08:23 -0700
                Re: Why Does the Metric contain a minus sign? Joaquin Cuocco <cicu@acacqjuc.co> - 2022-10-17 17:30 +0000
                Re: Why Does the Metric contain a minus sign? Jim Pennino <jimp@gonzo.specsol.net> - 2022-10-17 10:38 -0700
                Re: Why Does the Metric contain a minus sign? Joaquin Cuocco <cicu@acacqjuc.co> - 2022-10-17 18:43 +0000
                Re: Why Does the Metric contain a minus sign? Jim Pennino <jimp@gonzo.specsol.net> - 2022-10-17 12:19 -0700
                Re: Why Does the Metric contain a minus sign? Joaquin Cuocco <cicu@acacqjuc.co> - 2022-10-17 18:48 +0000
                Re: Why Does the Metric contain a minus sign? Jim Pennino <jimp@gonzo.specsol.net> - 2022-10-17 12:20 -0700
                Re: Why Does the Metric contain a minus sign? Joaquin Cuocco <cicu@acacqjuc.co> - 2022-10-17 20:08 +0000
                Re: Why Does the Metric contain a minus sign? Jim Pennino <jimp@gonzo.specsol.net> - 2022-10-17 14:22 -0700
            Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 02:33 +0200
              Re: Why Does the Metric contain a minus sign? rotchm <rotchm@gmail.com> - 2022-10-14 17:40 -0700
                Re: Why Does the Metric contain a minus sign? whodat <whodaat@void.nowgre.com> - 2022-10-14 21:44 -0500
                Re: yet another lurking imbecile *rotchm* uneducated and unskilled like hell Everet Baldini <rvia@nildiden.ii> - 2022-10-15 18:18 +0000
      Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-14 23:41 +0200
        Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-14 18:04 -0700
          Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-14 18:08 -0700
            Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-14 18:36 -0700
          Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 03:35 +0200
            Re: Why Does the Metric contain a minus sign? whodat <whodaat@void.nowgre.com> - 2022-10-14 21:40 -0500
              Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 19:54 +0200
                Re: the lurking imbecile *Thomas 'PointedEars' Lahn* putting the foot in his mouth again Everet Baldini <rvia@nildiden.ii> - 2022-10-15 18:10 +0000
                Re: the lurking imbecile *Thomas 'PointedEars' Lahn* putting the foot in his mouth again whodat <whodaat@void.nowgre.com> - 2022-10-15 14:04 -0500
                Re: Why Does the Metric contain a minus sign? Everet Baldini <rvia@nildiden.ii> - 2022-10-15 18:40 +0000
                Re: Why Does the Metric contain a minus sign? whodat <whodaat@void.nowgre.com> - 2022-10-15 13:53 -0500
                Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-17 00:41 +0200
          Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 03:37 +0200
            Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-14 19:09 -0700
              Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-15 01:39 -0700
            Re: Why Does the Metric contain a minus sign? whodat <whodaat@void.nowgre.com> - 2022-10-14 21:42 -0500
            Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-15 03:44 -0700
              Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-15 03:51 -0700
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-15 10:34 -0700
              Re: Why Does the Metric contain a minus sign? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2022-10-15 19:58 +0200
    Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-17 13:33 -0700
      Re: Why Does the Metric contain a minus sign? Joaquin Cuocco <cicu@acacqjuc.co> - 2022-10-17 22:25 +0000
        Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-17 17:27 -0700
          Re: Why Does the Metric contain a minus sign? Wilbert Sciacca <wcsc@iccstcwa.ia> - 2022-10-18 17:57 +0000
            Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-18 12:31 -0700
              Re: Why Does the Metric contain a minus sign? Wilbert Sciacca <wcsc@iccstcwa.ia> - 2022-10-18 19:47 +0000
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-18 14:29 -0700
                Re: Why Does the Metric contain a minus sign? Wilbert Sciacca <wcsc@iccstcwa.ia> - 2022-10-18 21:46 +0000
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-18 18:01 -0700
                Re: Why Does the Metric contain a minus sign? Wilbert Sciacca <wcsc@iccstcwa.ia> - 2022-10-19 19:43 +0000
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-19 17:40 -0700
                Re: Why Does the Metric contain a minus sign? Wilbert Sciacca <wcsc@iccstcwa.ia> - 2022-10-20 15:03 +0000
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-20 12:42 -0700
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-20 19:39 -0700
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-20 19:50 -0700
                Re: Why Does the Metric contain a minus sign? Ricardo Bassani <isis@nbcroiad.ai> - 2022-10-21 09:04 +0000
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-21 04:37 -0700
                Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-21 16:49 -0700
  Re: Why Does the Metric contain a minus sign? larry harson <larryharson66@gmail.com> - 2022-10-15 14:04 -0700
    Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-15 19:00 -0700
      Re: Why Does the Metric contain a minus sign? George Hammond <ghammond928@gmail.com> - 2022-10-16 11:14 -0700
        Re: Why Does the Metric contain a minus sign? Everet Baldini <rvia@nildiden.ii> - 2022-10-16 18:20 +0000

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