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From: Alexandre E Eremenko (no email)
Date: Fri Apr 07 2006 - 14:07:38 EDT
Perhaps this does not fit exactly in
the list scope but I will comment a bit about this funny subject
of the units.
On Fri, 7 Apr 2006, George Huxtable wrote:
> | We think of the metric system being firmly established in the world, but
> | only a part of it -- measurement of distance and temperature -- is
> | universal.
I am surprised with this statement.
If you subtract the US, from the rest of the world,
the metric system if firmly established in EVERYTHING
except time/angular measures.
Of course there is nothing good or natural about base 10 at all.
Bases 8 and 12 are much more convenient for many purposes.
I know of one attempt of transfer to base 8
(Charles XII of Sweden tried to introduce it as a general standard.
But he died young (and defeated)).
> Grads (100, not 90, to the right-angle) still appear on some French maps.
In Soviet artillery, at least when I served for a brief period in 1975,
the angle measurement unit was called simply "one division".
There were 6000 divisions in the full circle.
The reason for this was that 6 is a reasonable approximation to 2pi.
Thus an object of size 1 meter is seen at the distance of 1 kilometer
under the angle of 1 division, approximately.
So if you see a tank whose height is 3 meters under the angle
of 2 divisions, the distance is (3/2) times 1000=1500 meters,
very simple for quick calculation in your head:-)
But the precision instruments were also graded in "divisions"
to avoid confusion.
Confusion however occured in the interaction with
our aviation where the angles were naturally measured in degrees...
or with the navy where the distances were measured in cables
and miles but the angles still in degrees:-)
Grades were also used somewhere in the military but I don't remember
where:-)
But speaking seriously, probably one reason why the system based
on 60 still holds is that 6 is close to 2pi. Closer than 10 anyway:-)
Is there anything similar to the Soviet "division" in the West?
Alex.
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