On 2007 Dec 16 , at 3:02 PM, Martin Vlietstra wrote:
Of course, if we had a decimal time system we could have both. BTW,
if
anybody out there is a teacher of physics, one topic for an essay
would be
"Discuss the implications of the introduction of a time system based
on
100,000 seconds per day rather than 86,400 seconds in a day". A
good topic
to test an undergraduate's understanding of measurements, but probably
impractical.
Martin's hypothetical time system would be an absolute disaster
because it CHANGES THE SIZE OF THE SECOND.
Any change that changes one of the basic units (the 7 upon which
everything else is defined) would require changing the way we measure
hundred if not thousands of things not to mention requiring new
measuring instruments for all those types of measurements.
I was a physics teacher and I would never have given my students an
assignment that would be based on the drastic proposition of changing
one of the fundamental ways that all things are measured. Time of day
may be open to discussion but I think any discussion should start with
the premise that the SI second remains what it is.
I note that we have discussed aspect of the time-of-day problem (also
called "civil time") on this list before and it has generally
judged )by the various people who subscribe to this list) as being not
really on the subject of metric. Therefore, I will not discuss it here
any more than to condemn the idea of changing the size of the second
(which IS a metric subject).
I am, however, going to reply to Martin with a more complete
discussion of possible changes that could be made. Anyone else
interested in reading my ideas or discussing this issue further, may
let me know and I'll send them any further discussions we may have
outside of this metric list.
Bill Hooper
73 kg body mass*
Fernandina Beach, Florida, USA
* plus or minus a kilogram or so.
