On 2007 Oct 11 , at 2:04 AM, Metrication matters wrote:
Somewhat belatedly I have now considered (the) suggestions and
emended the article at http://www.metricationmatters.com/docs/
AWordAboutGlobalWarming.pdf accordingly.
But what is even more concerning is that when converting from one
to another, all these
different energy words also require thousands of conversion factors
if energy issues are to
be understood at even a basic level. The 93 measures above require
8556 conversion factors
to convert from any one measure to any other.
There is another way of looking at this (the number of conversion
factors needed). If done wisely, 93 different energy units would need
only 92 conversion factors* to convert from any one unit to any
other. That is, use only the conversion factors between the joule and
each other unit. Then, to convert a quantity in A-units to B-units,
merely convert the value in A-units into joules and then convert that
answer in joules to the value in B-units.
True, it now takes two steps to make any conversion instead of just
one, but it reduces the number of conversion factors from 8556 to 92.
I'd say the trade off is a good one. We've just saved 8464
conversions factors that we don't need to learn.
Your argument is of course not "wrong". It is also not necessarily
unfair (and I'm not suggesting that you change it). There are many
people out there who do not want to learn two conversion factors to
go from unit-A to unit-B. They are the ones who will want a single
conversion factor to solve their particular, narrow problem. To them,
it seems reasonable and necessary to need a list, somewhere, of all
8556 factors. The will accept your argument even while the more
astute will see that there is a short-cut.
Regards,
Bill Hooper
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*I am assuming that we use a single conversion factor between any
pair of units. That is, it is not necessary to know both that 1 inch
= 25.4 mm and at the same time also know that 1 mm = 0.03937 inches,
because it is possible to convert from inches to millimetres AND from
millimetres to inches using only ONE of those conversion factors
(either one). In one case you multiply, in the other you divide. If
we insist upon using both, so we can go either way by multiplying
something, then we would need double 92, that is 184 conversion factors.
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HAPPY METRIC WEEK!
