ATM was Interferometry vs. Legacy Testing

["B. Pepin" <atmjedit@conceptsnet.com>]

Hi Bratislav,

you wrote:
> There is only one linear SI unit and that is metre and its
fractions -milli,
> micro, nano, pico, femto, atto, zepto and yocto. ...

Allow me to point out that these are not multiple fractions, they are merely
spun off from one paltry fraction, 1/10. Other useful and naturally derived
fractions such as 1/24 (our time system), or 1/360 (celestial coordinates,
degrees) have no exact expression in decimal or SI units, which is its prime
deficiency. Say you have three guys dividing up a stock of polishing grit --
is it easier to give a third of an Imperial pound (four ounces), or does
each get .33 pound (or kilo, if you will)? In the latter case at least one
of the guys will get short goods. Maybe lose enough for that final wet. Do
you want to be that guy?

Actually, if you read my post, you will see that I do not say that the
Angstrom is an SI unit. In fact my joke merely asserts (with tongue in cheek
of course and using a false equivalency) the Angstrom is not in any
universal system -- unlike the Rayleigh Limit which is in fact
5797/1,000,000,000 English Inches (483 nanofeet or 147.25 nanometers) in
Sodium light, a usable parallel standard to anyone's degree of exactness.


---- Original Message -----
From: Bratislav Curcic <Bratislav.Curcic@ericsson.com.au>
To: atm <atm@shore.net>
Sent: Thursday, August 31, 2000 7:53 PM
Subject: ATM Re: Interferometry vs. Legacy Testing

>
> B. Pepin wrote :
>
> > Before you all start correcting me: The Rayleigh limit in Angstroms for
> > Sodium D light should be about 1472 1/4 . Thus, Angstrom was off by
almost
> > 4500 of the wrong units, not merely a hundred or so.
>
> Aside from this (quite poorly) fabricated 'proof' that imperial units are
> somehow superior, I will have one correction regardless : Angstrom
> is NOT a part of metric (SI) units.
> There is only one linear SI unit and that is metre and its fractions -
milli,
> micro, nano, pico, femto, atto, zepto and yocto.
> (and of course in other direction - kilo, mega, giga, tera, peta, exa,
> zetta and yotta).
> Anything else is not SI.
>
> Bratislav
>