I received this interesting reply to my email to the company that put
out the "Metric Clock/Metric Time" widget.
Bill Hooper
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Dear Dr. Hooper,
Wow! Thank you very much for your thoughtful letter. I never expected
our little clock widget to attract the attention of actual experts in
the field.
Let me begin by saying that the Metric Clock is intended to be
tongue-in-cheek -- it's an unrealistic idea for precisely the reasons
you have elucidated. Unfortunately my sense of humour is such that I
really did nothing to convey this intention.
I do think that it would be nice to use factors of ten wherever
physical reality doesn't recommend otherwise (you seem to agree), and
that it would not be conceptually difficult to replace the second with
the moment in the metric system and then -- keeping the
interrelationships intact -- recompute a new set of derived units (for
power, current, etc) from the new base units... but of course, in
practice, the process of actually moving to such a marginally improved
system would be ludicrously difficult and wasteful. Hence the joke. Ha
ha!
Rest assured that I fully support the metric system as currently
defined, and I salute the important work of metricators everywhere.
Keep up the good work!
Cheers,
Way Grander
Way Grander Enterprises, Inc.
www.madsense.net/waygrander
On 7/21/07, Bill Hooper <[EMAIL PROTECTED]> wrote:
Your proposal for metric time (as seen in your Apple Widget for a
metric clock) is incompatible with the International System of Units
(SI), which is the modern METRIC SYSTEM in use by 95% of the world's
population. It is incompatible because SI is based on a small number
of fundamental units, one of which is the second of time. ABSOLUTELY
ALL other measurements are related to these few basic measures, so
that modifying or discarding any one of them is tantamount to
destroying the entire system of measurements for the whole world.
It is the interconnection between all units that makes the SI metric
system powerful, not just the fact that units are related by simple
numbers like 10 and 100. You cannot tamper with one unit without
considering how it affects all others. (If you choose to leave all
others the same and use the "metric clock" ONLY for time of day, then
you are promoting two unrelated systems to learn and to use, instead
of just one. Also, since your "metric time" would be incompatible
with all other metric units, I think it would be ridiculous to call
your time "metric" at all.
Your time units are not metrically compatible with the SI second. The
"day" is the length of the day and it's length is determined
primarily by the rotation of the Earth on it's axis. The SI second is
defined as a size that makes the day equal
to 86400 seconds long (86400 s) on average. That leads to the
following for your other time measures (with some values in minutes
or hours in order to relate them to the old time units):
1 day = 86400 s (24 hours, of course)
1 deciday = 8640 s (2.4 hours)
1 centi day = 864 s (14.4 minutes)
1 milliday = 86.4 s (1.44 minutes)
1 moment = 8.64 s
None of these is related to the second by a simple factor and
therefore they are all incompatible with virtually ALL other
measurements. To give you just some samples of what I'm talking about:
The watt is used to measure power, which is how fast energy flows. It
is equal to the flow of one joule of energy PER SECOND. Thus, using
"moments" for the time unit in your system would cause the watt to be
equal
to 8.84 joules per moment. EVERYTHING that is measured in watts (and
kilowatts and megawatts and milliwatts) would have to be changed.
The ampere is used to measure the rate of flow of electric charge. It
is equal to one coulomb of charge PER SECOND. Substitute your
"moment" or any other of your units for the second and EVERYTHING
that is now measured in amperes (or milliamperes or kiloamperes)
would need to be changed.
Pascals are units of pressure and pressure is merely a force applied
to a surface divided by the area of the surface. Force is measured in
newtons and newtons are related to SECONDS, so that substituting any
of you units for seconds would change how all forces and all
pressures are measured.
I think the above shows that it would be monumentally difficult to
eliminate the second of time in favor of any one of your units. As a
result, we would then have to have all of your time units AND ALSO
the second (and the millisecond, the kilosecond, etc.) Far from
simplifying things, your system makes them more complex.
To make a small improvement in measuring time of day, your system
would make a monumental mess of virtually ALL other measurements for
95% of the people of the world. Sorry, but that doesn't seem to me to
be a good trade off. I hope you will abandon your effort to promote
your ill conceived metric time and metric clock.
Sincerely,
(Dr.) william Hooper
Certified Advanced Metrication Specialist
Professor of Physics (retired)
The University of Virginia's
College at Wise
