Dear USMA Folks,
The next edition (the ninth) of the SI Brochure is likely to reflect, as
you know, the shift to using seven exactly defined natural constants as
the basis for the SI. The process of defining values for those constants
in appropriate units effectively defines the SI base units. Currently,
the likely date of publication of the final draft for edition 9 will be
in 2018, give or take.
In anticipation of this, work has progressed in re-writing the SI
Brochure. I have posted here previous drafts of small sections of the
new material in the past, as well as some underlying documents that
discuss the nature of that shift of emphasis.
Now, a major portion of the new version of the Brochure's first three
chapters is available, courteously provided to us by Barry Taylor (NIST,
CCU). You may view the draft at, and download it from:
http://www.bipm.org/utils/common/pdf/si_brochure_draft_ch123.pdf
I have, so far, carefully read the first several pages (of 29) and have
skimmed the rest. Clearly this is a major rewriting of the Brochure and
not a tweak to update it. That is, it is a fresh start and not a patch.
So far, I am greatly impressed. The text flow starts "ab initio" in the
field of metrology and quickly develops the system from there. The flow
of information is smooth and clear to the careful reader -- at least one
experienced in the SI. And one **should** read it carefully. Like any
good technical writing the information content is concentrated; no
blathering appears in this document and every word is essential.
I will continue my careful study of this document. But in the meantime I
would like to put it out here on the list for you to see. Hopefully this
will start a lively and relevant discussion. One criterion that I think
we should gauge it by is how accessible it is to the neophyte, the
student, the general but decently educated member of the public. In
short, is it "teachable"? So far as I have read it, I think that it is.
Now, let's hear your opinions!
Enjoy!
Jim Frysinger
Chair, IEEE SCC14
