2014 April 3
Review of "SI An Educational Overview for Americans"
from Metricpioneer
review by Robert H. Bushnell
member USMA
This is a short book about the International System SI in the US.
It is uneven in its discussion but overall it is a good read.
A reason to change, not mentioned, is that the use of two sets
of units is expensive. It has been said that the cost to the US
GDP is near one trillion dollars per year. Now, this is big
money. Congress has so far not responded to this loss.
The book lists all the prefixes. The prefixes are an important
feature of SI. However most of the prefixes are not used. The
text does not tell which are found in general use in the US or
even in the world. The origins of the prefixes are given. This
is a good addition to the SI literature.
In the discussion of each prefix the word "abbreviated" is used.
The symbols for the units and prefixes are not abbreviations,
they are symbols.
An especially good feature of this book is that there is little
mention of inch-pound units (or whatever name you want for the
so-called customary units used in the US).
It has no index so it can not be easily used as a reference.
On page 5 the unit of measure for the maths list is not given. This
is obviously taken from a foreign reference.
The book sticks with the word "quantity" for the several properties
that are measured in this world. This awkward use of "quantity" is
taken from the CGPM documents so it is hard to avoid. To new
readers about SI, quantity means "how much." An introduction to
this use and meaning of the word Quantity would be helpful.
The chapter on Meter starts with "a unit of proper length." What
is a "proper" length? For an overview it would be better to leave
out the word "proper."
The base unit of volume is the cubic meter. The chapter on Liter
does not say this. Further, liter is a derived unit. And, those of
us who are picky picky about use of SI see "1 cubic decimeter" in
line 6. With spelled-out units, numbers are to be spelled out so it
should say "one cubic decimeter."
Many readers would like to see units for energy. There is no
mention of energy. The derived units for volume and speed are
discussed so why not other derived units like energy and power?
In fact, because the words energy and power are often misused
and confused in the press and TV, their not being here is a big
omission.
Let us hope that this short book gets a good reception.
