Re: Metric Time (was Re: Why not 13 months? (Was La Systeme Metrique))
Whittet (Whittet@shore.net)
12 Oct 1995 23:57:02 GMT
In article <45hm7q$5r5@lucas.emi.com>, phaedrus@ says...
>
>In article <45fbqr$3kd@shore.shore.net>, Whittet <Whittet@shore.net> wrote:
>>In article <45dt6q$cer@cnn.Princeton.EDU>, jrhodes@pupgg.princeton.edu says..
>.
>>>
>>>In article <45chpc$skj@shore.shore.net>, Whittet@shore.net (Whittet) writes:
>>>>all worked out into inches, feet, yards, rods, furlongs, chains etc;
>>>>to give a geocomensurate standard of measurement which is far more
>>>>precise than the meter and has withstood 5 millenia of use with
>>>>very small variation.
>>>
>>>
>>>The length of a meter is known to a very high precision.
>>
>>Yes, but it was supposed to have been geocommensurate, it is not
>>but the foot is.
>
>But the foot ISN'T geocommensurate.
>
>By your figures, the circumference of the Earth at the equator is
>24902.72727 miles (BTW, is that statute miles or nautical miles?
Statute miles, the nautical mile is a completely different animal
I
>guess it's statute, since there are 21600 nautical miles around the
>equator.). That works out to be 131 486 399.9856 feet.
>
>I checked, and it works out even IF that pattern of .7272 repeats.
>Which leads me to suspect that the number above was computed from a
>figure for feet/equator
The figure comes from averaging several sources.
Funk & Wagnalls encyclopedia gives 24902.4 mi
The Information Please Almanac gives 24902.4 page 343
Eighth Edition Surveying Moffitt & Bouchard cites the
Clarke Spheroid of 1866 = 24901.417 (Northern Hemisphere)
semimajor axis 6,378,206.4 m
GRS 80 Spheroid 6,378, 137.0 m
The Universal Transverse Mercator System also includes
Clarke 1880 (Africa)
International (South Pacific)
Everest (India)
Bessel (China)
New Spheroid pending (Australia)
>
>As a check, the largest of the three definitions for a nautical mile I
>have (6080.20 feet, pre-1959 US standard) gives a circumference of
>only 24873.545 statute miles (exactly 131 332 320 feet). The current
>nautical mile is about 4 feet shorter, at 1852m, making the equatorial
>circumference commensurate with the meter.
You are confusing nautical miles with THE MILE, a standard which
considerably predates the nautical mile.
>
>Using another method, I get the circumference of the Earth to be also
>less than the figure you cite. Granted, the nautical mile method
>gives commensurate feet/equators, but they are also subject to limits
>of precision.
> The International standard of the nautical mile is
>1852m, as I stated.
Since the meter is less accurate, taking a measurement in meters as
your starting point is the probable source of your error.
In feet, this is 6076.11548557 (to 12 significant
>figures) for 1 minute of arc on the equator, or 131244094.448 (to 12
>sig figures) feet/equator, not commensurate. However, my table also
>gave the naut.mi. as 6076.115ft, which leads to a foot commensurate
>equator, one about 9.5 feet shorter than the 1852m nautical mile.
>
>Where did you get your 24902.72727mi figure.
See above. It actually was just the best fit between all the values
I could find.
If you think about it, the earths circumference varies
due to expansion and contraction as the temperature changes, or
due to the moons tides, its axial wobble and plate techtonics.
The value is essentially established from the surveyed values of
more than a century ago.
I could give you a dozen other sources, but the point is that the metric
system is not as precise as some people would like to think, whereas
the value I gave you is incorporated into the Great Pyramid built c 2500 BC.
>
>If the equator really is commensurate with the foot, then it is pure
>coincidence, since, as you stated, the foot has been in use for
>millenia (in one form or another), longer than the notion of a round
>Earth has been popular with the foot-using population.
My interest was to see whether or not the assumption that
the foot was established as a standard of measure by the Egyptians
from good measures of the circumference of the earth and the length
of a year was reasonable.
>
>>
>> And
>>>since the foot is _defined_ in terms of the meter,
>>
>>The foot existed for millenia before the meter was invented. The fact
>>that the foot has a metric equivalent is part of the problem we are
>>discussing. Would you claim that all the things measured in feet
>>before there were meters are no longer in feet?
The Egyptian year was 360 days long. Interestingly enough the circumference
of the earth is 360 degrees.
A degree measures 365240 feet.
Suppose that is because a degree was defined as 365240 feet.
>>
>>
>>I don't hardly
>>>see how imperial units can be"far more precise" than the meter.
>>
>>Well for one thing there are exactly twice as many seconds in a century
>>as inches in the circumference of the earth at the equator.
>>
>>The circumference of the earth at the equator is 24902.72727 mi
>>There are 36524 days in a century
>>
>>365.24 x 100 x 24 x 60 x 60/24902.72727 x 5280 x 12 x 2=1
>
>365.24 x 100 x 24 x 60 x 60 = 3,155,673,600
>24902.72727 x 5280 x 12 x 2 = 3,155,673,599.66
>
>That these numbers are so close (and would probably be closer if the
>length of the equator was very slightly longer), and that the
>other methods for computing circumference I know of give significantly
>lower figures makes me believe that your figure for the equatorial
>circumference is made up to fit your argument. Where did you get your
>figure?
>
>I'm not accusing you of making it up. I just want to know who did?
The fact that the perimeter of the Great Pyramid is 1760 cubits, and
that there are 1760 yards in a mile is an interesting clue. To me it
suggests a relationship.
a royal cubit measures 7 palms;
a foot is 4 palms
a regular cubit is five palms
1 1/2 feet measures 6 palms.
>
>Also, the average length of a century is not 365.24, but 365.2425,
>which lengthens the century by 6 hours. Do you want an equator of
>24902.8977273 miles?
Sure, now it is, but how about 5,000 years ago when the standard
was established? My guess is that people got this accuracy by measuring
carefully and repeating their measurements a very large number of times.
>
>And what matter does it make if a particular unit is commensurate with
>the equator? How often do people measure the equator to within a
>meter? For that matter, given the dynamics of the ocean, the moving
>tidal bulge, etc, how would you measure the equator to within a meter?
The point is that it would show that people 5,000 years ago knew more
than they are generally credited with having known.
>
>One of the two systems under discussion has a historical link to being
>defined in terms of global distances over the surface of the Earth
>(and that wasn't equatorial, but pole-to-equator). It hasn't been
>defined that way for at least 150 years. The other system has a
>historical tie to being the average length of a man's foot, and
>standardized to the foot length of a particular man. But it too
>hasn't been defined that way for several centuries.
This myth about the English foot being established in the middle ages
ignores its roots in the Roman foot For that matter the roots of
the Roman foot lie in the Greek foot. The Greek foot came from the
Phoenicians, and they got their measures from Egypt.
>
>Both systems are good for measuring, which you choose to use depends
>on a) what system you are most familiar with, and b) who you wish to
>communicate with (and what system they use). To me, 1 cup is as good
>as 250ml, and 6 inches is as handy as 15 centimeters, and 20C is as
>good for me as 68F.
pints and other volumetric measures are based on an octagonal scale
of cubic inches.
1 tablespoon is 1 cubic inch
1 handful 2 cu in
1 jack 4 cu in
1 gill 8 cu in
1 cup 16 cu in
1 guart 64 cu in
1 pail 512 cu in
1 keg 1024 cu in
1 bushel 2048 cu in
1 barrel 8192 cu in
1 hogshead 16,384 cu in
1 pipe 32,768 cu in
and so forth
>
>stuff deleted
>--
>Buddha Buck
Steve
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