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Re: SI units.. Re: Capacitance HELP



Original poster: Ed Phillips <evp@xxxxxxxxxxx>

Tesla list wrote:

Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>

At 03:57 PM 1/17/2006, you wrote:

Original poster: Ed Phillips <evp@xxxxxxxxxxx>


femtofarad. With SI you have to learn a lot of arbitrary names like "atto", unlike the old bad system where milli and micro were pretty ambiguous and therefor to "be denegrated". Denigrate is a favorite word to SI


                                   ^^^^^^^^^

followers.



Ummmm...... don't you mean "deprecate"?  We do that all the time in
programming.  Technical meaning: to declare something obsolete--
"stop using this because it might just go away in the future (with
possibly short notice), and there is a new and better replacement".

--ian

P.S. Surely they denigrate too...."

In the "SI Manifesto's" I've read the new (and supposedly better) name is given followed by a statement that the use of the old (familiar and perfectly useful) name "is denigrated". Don't think these authors (some of whom must be young college students who've gotten "the SI religion") have run across the word deprecate yet. These are the same kind as those who write the editor of a magazine pointing out errors in punctuating numbers in other than the SI system, or who write that something was built out of "lumber 5.08 x 10.16 cm" instead of "2x4's", apparently ignorant of the fact that it's been a long time, if ever, that finished lumber came in dimensions of 2" x 4". Different isn't necessarily better!

Ed



But Ed, you've forgotten.. one should always explicitly give an uncertainty specification as well:

The structure was constructed of lumber measured (footnote 1) to have a mean cross section height (referring to the shorter cross sectional dimension) of 50.8 mm (with a calculated measurement uncertainty of 0.1 mm, 2 sigma) and a cross section height standard deviation of 1.5 mm (measurement uncertainty of std dev of .1mm, 2 sigma).(footnote 2)


1) Lumber measured with scale calibrated to secondary transfer standard #xyz, traceable to NIST length standard #abc. Calibration was performed on 1 Jan 2000. 2) Measurements performed in a laboratory environment with temperature controlled to 20.0C (uncertainty of 1 degree, 1 sigma), etc.etc.et

Right you are; lots more scientific that way. Of course, in the IEEE Spectrum, my hated IEEE funny book, the uncertainty is about 100% for everything published.

Ed

.