On Thu, 13 Nov 2003 17:48:04 GMT, "BruceS" wrote:


"Gene Nygaard" wrote in message
news
On Thu, 13 Nov 2003 16:05:24 GMT, "BruceS" wrote:


"Phred" wrote in message
...
In article , "John Gilmer"
wrote:



Might the "hand", being almost exactly 0.1 meters, end
up one day as a handy nickname for the decimeter?

Maybe.

After what those dirty rats did to the nautical mile (no longer 6280')
anything is possible!

Must say I always thought the nautical mile was 6080 feet. But, yes,
even so, that "approved" definition of 1852 m is only about 6076 feet
http://physics.nist.gov/cuu/Units/outside.html
so I could now miss my favourite coral trout bombie by 40 feet! :-(

AIUI, the nautical mile is one of the few "old" measures with a rational
basis. It is the distance along the Earth's circumference at the equator
that equals one minute of arc.

No, it is not.

There were some geographical miles based on the equatorial
circumference; the ones I have seen used were 4 minutes of arc, or
about 7.421 km. But nautical miles are not and never have been based
on the equator.

A minute of arc at sea level on the equator is about 1855.325 m, or
6087.023 ft. That's 1.0018 international nautical miles, or 1.0012
U.K. Admiralty miles, or 1.0011 of the old pre-1954 U.S. nautical
miles.

However, if you go north and south across the equator, a minute of arc
(for the normal geodetic latitudes) is less than 0.9950 international
nautical mile.

Show me anybody's nautical mile that was equal to a minute of arc on
the equator.

Try these:
http://dnr.cbi.tamucc.edu/Waves/Naut...on?action=diff
http://people.howstuffworks.com/question79.htm
http://www.tpub.com/content/engineer.../14071_198.htm
http://www.subsowespac.org/wwwboard/messages/269.html

You've got to learn to do a better job evaluating the credibility of
your sources.

Go look up the radius of the Earth at sea level at the Equator, or
the circumference there. You can find it in most printed
encyclopedias or almanacs, or at thousands of sites online, with
slightly varying numbers based on various reference ellipsoids that
have been used over the years. No, it isn't anywhere near the 40,003
km that one of your sources above stole from the other. It is about
40,075.0 km to 40,075.2 km on all the 20th or 21st century ellipsoids.
For example, an equatorial radius of 6378.137 km in WGS-84, or a
radius of 6378.160 km in Geodetic Reference System 1967.

Then do the math yourself. How long is one minute of arc at the
equator, in terms of meters or feet?

Gene Nygaard

"It's not the things you don't know
what gets you into trouble.

"It's the things you do know
that just ain't so."
Will Rogers


If there is a need to make the relation of
meter to nautical mile use fewer digits, it is the meter that should be
adjusted. I'm outraged, simply outraged, that the noble nautical mile
should
be compromised for the benefit of the lowly meter.

We don't have a perfectly round earth. That's the problem.

Do you have a proposal to correct this problem?

The meter, exactly like the nautical mile, and unlike feet and statute
miles, *is* based on the Earth.

A centigrade is to a kilometer as a nautical mile is to a minute of
arc.

So if they were based on the same midrange value, or if we really had
a perfect sphere for the Earth, we would have 1 km = 0.54 nmi exactly.

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

"John Gilmer" writes:
There is NOTHING magin about the metric system except for the fact that
units differ by powers of TEN.

Apart from the minor fact that almost everyone (19 out of 20 people
on this planet) uses it, you mean?

And of course the fact that it is a coherent system, without a need
to memorize any unit-specific conversion factors in physics formulas?

And of course the fact that a surprising number of useful everyday
quantities such as

- earth gravity (~10 m/s^2)
- water density (~1000 kg/m^3)
- length of equator (~40000 km)
- speed of light (~300000000 m/s)
- atmospheric pressure (~100 kPa)
- recommended serving temperature of American soft drinks (0 deg C)
- recommended brewing temperature of English breakfast tea (100 deg C)

etc. happen to to be within about 1-2% of a round number, making
the metric system unbelievably convenient for quick estimates
with mental arithmetic.

Not to forget convenient approximations such as

- length of an adult's step (~1 m)
- width of an adult's hand (~0.1 m)
- width of the nail of the small finger (~0.01 m)
- an hour's drive by car (100 km)
- an hour's walk (10 km)

Can you name even a single country that adopted its customary
units from the US?

Why do you think did almost every country decide independently
to move to the metric system during the past 200 years?

Markus

There is NOTHING magin about the metric system except for the fact that
units differ by powers of TEN.

Apart from the minor fact that almost everyone (19 out of 20 people
on this planet) uses it, you mean?

Gosh!

Well, sport, 49 out of 50 people (on this planet) don't qualify for Mensa.


And of course the fact that it is a coherent system, without a need
to memorize any unit-specific conversion factors in physics formulas?

Un huh.

You HAVE heard of the kilogram FORCE

unit, haven't you?


And of course the fact that a surprising number of useful everyday
quantities such as

- earth gravity (~10 m/s^2)

Well, in "English" its 32 ft/s^2 and 32 is a power of 2 (isn't "binary" more
"rational" than decimal?).

- water density (~1000 kg/m^3)

A pints a pound the world round!

(64 lbs/ft^3) (IOW another power of t
wo)
- length of equator (~40000 km)

So? in English its about 25,000 miles.

- speed of light (~300000000 m/s)

So? 186,000 miles/second!

- atmospheric pressure (~100 kPa)

14.5 psia

- recommended serving temperature of American soft drinks (0 deg C)

Or 32 F (another power of two).

- recommended brewing temperature of English breakfast tea (100 deg C)

But coffee (which AMERICANS prefer) is best brewed at 200F.


etc. happen to to be within about 1-2% of a round number, making
the metric system unbelievably convenient for quick estimates
with mental arithmetic.

Not to forget convenient approximations such as

- length of an adult's step (~1 m)

Well, a mile is 1,000 paces of your standard Roman Legionair type!

- width of an adult's hand (~0.1 m)

Length of an adult's foot is ONE FOOT.

- width of the nail of the small finger (~0.01 m)

ReallY? Thumb join is 1".

- an hour's drive by car (100 km)

Well, for most drivers who "bend" the limit just a "little", its 64 miles
(another power of 2).
- an hour's walk (10 km)

More like 3 MILES.

Can you name even a single country that adopted its customary
units from the US?

Who cares?


Why do you think did almost every country decide independently
to move to the metric system during the past 200 years?

Because they all fell for the "scientific" crap as did you.


Markus

On Thu, 13 Nov 2003 18:33:15 -0500, "John Gilmer"
wrote:



There is NOTHING magin about the metric system except for the fact that
units differ by powers of TEN.

Apart from the minor fact that almost everyone (19 out of 20 people
on this planet) uses it, you mean?

Gosh!

Well, sport, 49 out of 50 people (on this planet) don't qualify for Mensa.


And of course the fact that it is a coherent system, without a need
to memorize any unit-specific conversion factors in physics formulas?

Un huh.

You HAVE heard of the kilogram FORCE

unit, haven't you?

I've heard of it. The CGPM endorsed it, and made it well defined for
the first time (at a time when pounds force had also never been well
defined), way back in 1901 by adopting a "standard acceleration of
gravity," a concept of metrology and not of physics, something which
serves no other purpose than to define a unit of force based on a unit
of mass. BTW, nobody in the U.S. and perhaps not anywhere else has
ever officially adopted an official value for the purpose of defining
pounds force.

That kilogram force (aka kilopond) is not part of the International
System of Units. The vestiges of its use should be eradicated; Japan,
one place that still had significant use of this obsolete unit, made a
concerted effort to get rid of most of its use a few years ago.

That's another important thing about the metric system--it is the only
system today that is still fully supported and updated. Anything else
is like old, orphaned software.

Nobody will ever bother telling us to quit using using pounds force,
without telling us not to use pounds of any sort. That system is no
longer updated.


And of course the fact that a surprising number of useful everyday
quantities such as

- earth gravity (~10 m/s^2)

Well, in "English" its 32 ft/s^2 and 32 is a power of 2 (isn't "binary" more
"rational" than decimal?).

- water density (~1000 kg/m^3)

A pints a pound the world round!

That never was true, even if the "world" stops at the U.S. border.

Check this out:
http://w0rli.home.att.net/youare.swf

A cubic foot of cool water equal to 1000 oz avdp is an accident that
is much closer to true.

(64 lbs/ft^3) (IOW another power of t
wo)
- length of equator (~40000 km)

So? in English its about 25,000 miles.

Which miles? How many feet is that?

- speed of light (~300000000 m/s)

So? 186,000 miles/second!

- atmospheric pressure (~100 kPa)

14.5 psia

Sure. Real handy. But what is it in inches of mercury, the units the
National Weather Service uses for atmospheric pressure? How do you
convert between your "psia" and those inches of mercury? How can you
remember which one is 14.5 and which one is some other number?

- recommended serving temperature of American soft drinks (0 deg C)

Or 32 F (another power of two).

Well, if you think that you can multiply and divide a temperature in
either degrees Fahrenheit or degrees Celsius by some number and get
anything meaningful, you really are stupid. Powers of two are of no
significance.

- recommended brewing temperature of English breakfast tea (100 deg C)

But coffee (which AMERICANS prefer) is best brewed at 200F.


etc. happen to to be within about 1-2% of a round number, making
the metric system unbelievably convenient for quick estimates
with mental arithmetic.

Not to forget convenient approximations such as

- length of an adult's step (~1 m)

Well, a mile is 1,000 paces of your standard Roman Legionair type!

After a switch to apply to a longer pace of 5 English feet, before an
additional 280 feet were gratuitously added by Elizabeth I, to make it
come out to a whole number of furlongs in a different system of units.

- width of an adult's hand (~0.1 m)

Length of an adult's foot is ONE FOOT.

- width of the nail of the small finger (~0.01 m)

ReallY? Thumb join is 1".

- an hour's drive by car (100 km)

Well, for most drivers who "bend" the limit just a "little", its 64 miles
(another power of 2).
- an hour's walk (10 km)

More like 3 MILES.

Can you name even a single country that adopted its customary
units from the US?

Who cares?

There is at least one, of course. Its capital is named after our 5th
President. Aren't you swelling with pride that they followed our lead
in their units of measure?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

On Thu, 13 Nov 2003 14:01:16 -0500, "John Gilmer"
wrote:



We don't have a perfectly round earth. That's the problem.

The meter, exactly like the nautical mile, and unlike feet and statute
miles, *is* based on the Earth.

WAS and not "Is."

Still "is" in the same sense as the nautical mile is.

You are right that the meter is no longer precisely defined based on
the Earth, and never really was, because nobody had an accurate
estimate of that before the first standard meter bar was constructed
in the 1790s.

But the same is true of the nautical mile, now most often defined as
1852 m. Just making sure that you aren't one of those who want to
have it both ways, claiming that the nautical mile is based on the
Earth and the meter is not.

Those "rational" folks who first invented the meter f*cked up.

No, they got damn close, when they took on a difficult task. We can
do a little bit better now, a couple of centuries later--but not much
better at all just using traditional surveying methods.

Measure an arc at sea level on Earth in grads, and it will still be
over 100 km in some places and less than 100 km in other places. In
other words, the meter as now defined still fits the earth. There is
no real significance in the particular meridian quadrant through
Paris.

Exactly how far off were they, anyway? If you go by the length of a
meridian quadrant on the Geodetic Reference System 1967 ellipsoid,
they'd be off by about 2.0 km in 10000 km. That's 0.020%, pretty
good. But if you go by the length of a meridian quadrant in the
WGS-84 ellipsoid, they are only off by 1.7 km in 10000 km--or is it
1.97 km? Whatever, it certainly differs from the value for other
ellipsoids that have been used, if you get down to the nearest meter.

How long is the actual meridian quadrant through Paris, if it were
measured as accurately as possible today? We don't know, because
measuring it is still difficult enough that nobody had even tried to
recalculate it. That 0.02% is a good ballpark estimate.

Still fits the earth well enough to that 0.01 grad along the equator
is about 1001.9 m, but 0.01 grad (geodetic latitude) going N-S across
the equator is about 995 m.

The meter
was re-defined as the distance between two marks on a Pt. rod kept at a
certain temperature. As technology marched on more "universal" standards
of length (and time, etc.) were invented. Usually the "new" standard was
close enough to the old for the accuracy required for most commercial,
surveying, or navigation purposes.

There is NOTHING magin about the metric system except for the fact that
units differ by powers of TEN.

There are several more important factors, including the fact that it
is used all around the world, including in many applications in the
United States.

The number 10 isn't even the most important number in the modern
metric system. The number 1000, with preferred prefixes those which
are powers of 1000, is also pretty important. But the number which is
really important is the number ONE. The SI is a "coherent" system of
units, as that term is used in metrology. That means that all the
derived units are some unitary combination of the base units.

This just isn't much of an advantage for most human activities. The "step"
size of 10 times is just TOO BIG!

A step size of 10 is 100 times too small. We'd all be better off if
the whole world forgot "centi" and almost nobody uses "deka-" and
"deci-" and "hecto-" anyway. But a whole lot a classroom time is
wasted teaching those useless prefixes. The CGPM ought to have had
enough sense to consign them to the same fate as "myria-" and all the
double prefixes which used to be acceptable, such as micromicrofarads
and hektokilometers and micromillimeters (aka millimicrons, where even
the micron name is no longer acceptable).


Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

Markus Kuhn wrote:
"John Gilmer" writes:
There is NOTHING magin about the metric system except for the fact
that units differ by powers of TEN.

Apart from the minor fact that almost everyone (19 out of 20 people
on this planet) uses it, you mean?

And of course the fact that it is a coherent system, without a need
to memorize any unit-specific conversion factors in physics formulas?

And of course the fact that a surprising number of useful everyday
quantities such as

- earth gravity (~10 m/s^2)
- water density (~1000 kg/m^3)
- length of equator (~40000 km)
- speed of light (~300000000 m/s)
- atmospheric pressure (~100 kPa)
- recommended serving temperature of American soft drinks (0 deg C)
- recommended brewing temperature of English breakfast tea (100 deg
C)

etc. happen to to be within about 1-2% of a round number, making
the metric system unbelievably convenient for quick estimates
with mental arithmetic.

Not to forget convenient approximations such as

- length of an adult's step (~1 m)
- width of an adult's hand (~0.1 m)
- width of the nail of the small finger (~0.01 m)
- an hour's drive by car (100 km)
- an hour's walk (10 km)

Can you name even a single country that adopted its customary
units from the US?

Can you name a single country that reached the spectacular levels of
power, productivity, and wealth as the US - which did it without the
metric system?

Why do you think did almost every country decide independently
to move to the metric system during the past 200 years?

Markus

"Bob Harrington" writes:
Can you name even a single country that adopted its customary
units from the US?

Can you name a single country that reached the spectacular levels of
power, productivity, and wealth as the US - which did it without the
metric system?

Economic success is driven by a large number of factors, of which
the choice of units of measurements is clearly quite negligible
compared to other factors, for example social security policies
or whether your currency is overrated because of its reference
role in the energy market.

Putting aside the fact that Japan and Germany have not been doing
particularly well economically during the past decade, both countries
have clearly been most formidable industrial powers and by all means a
match for the US in terms of economic growth for most of the 20th
century. There are numerous examples of smaller economies (India and
Ireland come to mind as shining examples), where the move to the metric
system coincided with substantial and sustained economic and
industrial development.

If you look at a more short-term view, let me also remind you that
the US is at present the only country that finds it necessary to
reintroduce trade tarifs to protect its uncompetitive non-metric steel
industry, a step that was recently declared illegal by the WTO. Poverty
levels in the US are unmatched in the EU. The inch-based human
spaceflight programme, originally conceived entirely as a media-effective
national prestige stunt, is in shambles.

The metric-based JPL space probes, as well as the metric US Department
of Defence, on the other hand seem to be doing rather fine these days, as
is the mostly metric semiconductor industry. With a bit more work, it would
not be difficult to make the case that the most successful enterprises
the US undertakes TODAY are already done metric. Running some an inch-pound
business is today a good indicator that you are a member of the tail end of
the US economy!

Can you name even a single country that adopted its customary
units from the US?

You raise an interesting point.

The two nearest neighbors of the US use the metric system.

Let us consider the Mexico/US border.

On one side you have the richest society in the world. On the other side
you have a metric system and third world living standards!

Or, (for you racists) take the US/Canader border: By the standards of the
US, Canada doesn't have a significant military establishment. Yet it
manages to have a lower relative national wealth. It has MUCH more OIL and
gas than the US, etc. etc.

SO: just WHAT IS THE PROBLEM with Canader and Mexico?

The Answer: The METRIC SYSTEM!

In article ,
"John Gilmer" wrote:
[ And managed to lose previous attributions... Tsk, tsk. ;-)

There is NOTHING magin about the metric system except for the fact that
units differ by powers of TEN.

Apart from the minor fact that almost everyone (19 out of 20 people
on this planet) uses it, you mean?

Gosh!

Well, sport, 49 out of 50 people (on this planet) don't qualify for Mensa.

****! I'm one in fifty! (My opinion of course. :-)
[...]
Not to forget convenient approximations such as

- length of an adult's step (~1 m)

Well, a mile is 1,000 paces of your standard Roman Legionair type!

Frankly, I suspect you're both wanking here. I know there are some
macho types who *assume* their pace is one metre, but most barely make
it to one yard -- and as for those Romans with a pace of over 5 feet,
well they were either bloody big *******s, or they were running.
[The standard army pace in Oz is 30 inches, the rate is 120 paces per
minute, which gives you a marching speed of 100 yards/minute or about
3.4 mph. But then (50 years ago anyway) the routine was to march 50
minutes and rest for 10, so distance covered was a bit over 2.8
miles/hour.


Cheers, Phred.

--
LID

In article ,
wrote:
On Thu, 13 Nov 2003 14:01:16 -0500, "John Gilmer"
wrote:
[...]
The number 10 isn't even the most important number in the modern
metric system. The number 1000, with preferred prefixes those which
are powers of 1000, is also pretty important. But the number which is
really important is the number ONE. The SI is a "coherent" system of
units, as that term is used in metrology. That means that all the
derived units are some unitary combination of the base units.

WhenI was at secondary school the "standard" metric system being
taught in physics/chemistry was the CGS system. However, our science
master was astute enough to realise that the MKS system was the way of
the future, so he taught us both.

Now, some decades down the track, the thing I still find most annoying
about claims for the "rationality" of the SI is the bloody kilogram!
If the kilogram is a basic unit, then the gram should be a
millikilogram.


Cheers, Phred.

--
LID