Your "pi" example does not work. Pi is not a definition. the length of an inch has changed many times over the centuries so there have been many definitions. So yes 2.54 mm is the current definition but there are others and you only have to go mack to 1958 to find that another definition of the inch was used.
Yes the length of the inch actally changed. So in theory any ruller or machine tools or micrometer made in work war II era has been wrong for a long time. But fortunately the change was tiny at the 1/10,000th level The lllength of the inch, foot, yard and so on all changed a little over 50 years ago so that we could have exact and easy conversions to and from the rest of the world's units. On Tue, Jun 25, 2013 at 10:52 AM, J. Forster <j...@quikus.com> wrote: > No. It's THE definition... there is only one. > > It's not like Pi, which equals 3 for small circles. > > -John > > =============== > > > > > In message > > <caf_se-av85uzwvkp2zeil10dcdeohroj0wne1d-13vawcwt...@mail.gmail.com> > > , Robert Darlington writes: > > > >>Machinists know that 1 inch is exactly 2.54cm or 25.4mm. It's a > >>definition, not a coincidence. > > > > The crucial word in that statement being "a" :-) > > > > -- > > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > > p...@freebsd.org | TCP/IP since RFC 956 > > FreeBSD committer | BSD since 4.3-tahoe > > Never attribute to malice what can adequately be explained by > > incompetence. > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > > > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
