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Old 14-11-2014, 17:42   #256
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Re: Convenience of the metric system

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Originally Posted by K_V_B View Post
No, I can do this in my head.
Now you tell me: After I've decided in in 8 sections, how many degrees does one section measures?
You're deflecting here.

This is where everyone arguing against 360 degree circles washes up (what about 22 and a half degrees?!), and the fault is mine for explaining wrongly. One does not simply divide each sector in half each time, rather the progression that results in 360 is 2x2x2x3x3x5. The Gon and Radian system also get to half-units just a few divisions along, so that problem is common to all three. But I must pause here and apologize--I worked the 400 and 500 circle divisions out on paper, and they too have exact reciprocals, so I reluctantly admit to being wrong--which means they would be as good as the 360 degree circle, except that 360 is still more versatile, being divided by all of the first 12 numbers except for 7 and 11, and is the smallest number divisible by 10, 20, 30, 40, 60, and 90. The ancient Egyptians (who were pretty decent astronomers) are thought to have chosen it partly because of that, and partly because of the relation of the sun's apparent diameter to the degree. I can't know this for sure, but I do know that it works well enough that I don't desire a different circular measurement.

Again, UTM has its purpose. It is not celestial navigation. It's purpose is to make it easy to calculate distance and bearing for nearby position without having to use complicated formula.
For that purpose it works very well. I don't see UTM used a lot outside of the army.

You're now making an argument similar to "a spanner is a bad tool because it sucks at sawing".

Thanks for the illustration. I find using the metric system is exactly like trying to saw with a spanner


I know that they don't exist. Mostly because the only persons doing geospatial calculations in metres and "grade" are surveyors in some continental European countries. And they don't use a nautical almanac as it isn't accurate enough.
But my point is only that, in a parallel universe where we would use the meter and the grade for navigation the formulas would remain the same, and the problem would be probably a bit less complex as you wouldn't need to convert back and forth between D.M.S and decimal degrees.
I'm not saying that we should do this. I'm just trying to make the point here that inherently the nautical mile isn't "more sensible" then the metre.

But then it is not less sensible, either. So why throw out what works perfectly, and has worked since antiquity, simply because someone invented a new length to use as a standard? And then couldn't decide on the definition of it for decades?
No, the Russians could not have put a man on the moon. It has nothing to do with systems of measurement.
The Russians simply didn't have the resources to go to the moon because their political system crippled their economy.
You say economy, I say metric system. Why d'you think the Japanese and the Germans were soundly beaten in WWII? Because the English and the Americans had not sold out wholesale to the metric system. Can you say with any certainty that this is not so? They were metricking; they lost. HMMM.



Because I've been involved in making charts and maps. I'm a surveyor by education, and made my final dissertation on the (then nascent) GPS system. If my life would have only taken a different turn I would now probably be working for the Belgian or Dutch hydrographic authority, or one of the big dredging multis. In stead I fell for a woman living in a landlocked country and ended up sailing lakes, making passages on other people's boats and dreaming of cruising...

Nevertheless, I have a lot knowledge about the theory behind map and chart making, about navigation and the theory of determining one's position, probably more then most sailors.
When I first started looking at GPS the charts we had didn't yet use WGS84, and I had to write a program to convert the coordinates myself.

I will not claim to be very experienced in the practice however.

I do not question your education or acumen--I only point out that practical experience in the thick of things beats all the theories in the world.

Looking at the maps of the North Sea area lately I saw quite a bit of evidence of the area having been thoroughly resurveyed. To the point that bottom contours are now actually to detailed...
With modern technology surveying an area in high detail in a short time without needing a lot of manpower is quite easy.

Sure we have better bathyspheric equipment than sounding lines nowadays, but that is not thanks to the Metric system. The bottom of the North Sea could be more accurately charted nowadays in Cubits, if they wished, thanks to equipment, not to what measuring unit is used. And the fact that the North Sea is well charted speaks nothing to the thousands of charts still in use without a speck of metric on them.




My friend, in the real world most people use the metric system.

Let them: I find the metric system to be cold and without soul, without intuition, or poetry, or any beauty. Limited to tenths and hundredths and thousandths--give me thirds, and quarters, and fifths and eighths and halves and thirty-seconds. Give me lengths I can relate to, give me depths in which the far reaches of the globe were first explored. Give me a circle evenly divisible by the number of hours in a day, give me segments of arc that I can correlate to the movement of the cosmos overhead as I steer my boat through velvety nights.


As originally intended the metre was also defined as a useful fraction of an arc measured on the surface of the earth. Later, for more accuracy it was redefined in a different way.

However, someone in this thread insists on finding this a silly notion, which is why I pointed out that for the nautical mile exactly the same thing was done.
The idea is not a silly notion: what is silly is that they thought they needed to make a new system when a perfectly good one existed, and then that they calculated wrongly when they set it up. A very inauspicious beginning.

I apologize also for not knowing how to separate my answers within the quoted portion from the quotes--I hope you can pick out what parts are the quote and which are my responses. Other than by seeing which one makes more sense (grin)
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Old 15-11-2014, 05:26   #257
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Re: Convenience of the metric system

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The idea is not a silly notion: what is silly is that they thought they needed to make a new system when a perfectly good one existed, and then that they calculated wrongly when they set it up. A very inauspicious beginning.
At the time the metric system was designed "a perfectly good one" did not exist. That is the reason they designed it.
At that time every city in France had it's own definition of the length of a foot, of the weight of a pound. It was the same everywhere else in Europe.
At that time every seafaring nation had it's own definition of the length of the Nautical mile.
At the end of the 18th century most educated people in continental Europe, but also in the UK and the US perceived problems with the system of measurement in use. This was a period of scientific progress, and increases in international trade. Scientists had trouble however communicating with their peers in other countries. James Watt complained that he couldn't sell his machines in Germany because the differences in measurement units used. There was an increasing need for higher precision in manufacturing, and the fact that the foot varied by several PPM across the British empire was a problem.
Several proposals were made to create a new system, and at first it even looked like France, the UK and the US might have even agreed on a common system. Jefferson was in favour of a decimal system:
Plan for Establishing Uniformity in the Coinage, Weights, and Measures of the United States - Wikipedia, the free encyclopedia

The metric system resulted in a large part of the world finally using the same measurement system.
In the "customary unit" world it was not until 1853 that everyone agreed on how long a foot had to be. And it wasn't till 1970 that the US and the UK finally agreed upon a definition of the Nautical mile...

Btw, the "mistake" the scientists made when measuring the length of the meridian through Paris was only about 1/100000. And it really doesn't matter, as what counts is not how long the basic unit is, but that everyone understands it and uses it to the highest accuracy possible.

Quote:
I apologize also for not knowing how to separate my answers within the quoted portion from the quotes--I hope you can pick out what parts are the quote and which are my responses. Other than by seeing which one makes more sense (grin)
It's not hard. You start a block word "quote" within square brackets. You end it with /quote within square brackets.
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Old 15-11-2014, 17:05   #258
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Re: Convenience of the metric system

^^ Thanks. I'll try the quoting thing in future. In the meantime, I find it telling that so much was done with feet and miles in the world of exploration and cartography and navigation both before and after the metric system hove into view. I like to feel that the circular measurements I use, the time I use, the way they relate to navigating have their roots in antiquity--a vital, real connection to the past. Sentiment? no doubt: but the foot and fathom, yard, nautical mile, minute, second and hour, as they stand today (however you wish to define them), work together wonderfully to get me where I need to go without computers, programming, or electronical aids. Since charts and almanacs and sight reduction tables and time as we currently know them are not compatible with exclusive metric use, I find it far easier to think and live and exist in the system that is.
I've enjoyed hashing things out on this thread; I hope that those who keep rising up to bash all us non-metrickers have learned to understand that there is more than one opinion in the world; that maybe humanity is better served by diversity than a straitjacket uniformity.
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Old 15-11-2014, 18:23   #259
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Re: Convenience of the metric system

Basically imperial is humanistic and more understandable and thus often easier to use in some everyday apps, especially in many marine apps. And metric is more formal, abstract and not "gut" based system but in the brave new world of nanoseconds and nanometers is much more precise and workable than the human level imperial system. Both have their pluses and minuses. And for some apps one is significantly better, easier than the other. Of course if you build a house by rough sketches and generations old know-how and without much modern equipment imperial with its feet, yards and cubits is the one to use. But if you need precision on 1/10000 inch scale no way can you easily use imperial and you have to go to metric.

Just my 2c.
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Old 15-11-2014, 18:29   #260
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Re: Convenience of the metric system

So is 1/10000 of a inch metric, or Imperial ? Or both ?

I still say it's fear of fractions.

Fear not my European friends we(USA) switched to metric for booze, and ice cream.
And it still irritates the hell out of me.
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Old 15-11-2014, 18:34   #261
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Re: Convenience of the metric system

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So is 1/10000 of a inch metric, or Imperial ? Or both ?
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Old 15-11-2014, 22:54   #262
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Re: Convenience of the metric system

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Originally Posted by Andrew B. View Post
So is 1/10000 of a inch metric, or Imperial ? Or both ?

I still say it's fear of fractions.

Fear not my European friends we(USA) switched to metric for booze, and ice cream.
And it still irritates the hell out of me.
Hey - if you've switched for booze - the end of the imperial system is near
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Old 16-11-2014, 02:07   #263
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Re: Convenience of the metric system

Imperial Question:
Which is heavier - an once of gold or an ounce of feathers?

Answer: an ounce of gold.


Metric Question:
Which is heavier - a kilogram of gold or a kilogram of feathers.

Answer: they both weigh the same.

So tell me which system is better for determining mass (weight).
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Old 16-11-2014, 06:01   #264
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Re: Convenience of the metric system

I've just read the beginning of this thread, and the end of it.

But have to respond...mass is not weight.

FWIW, I grew up with the Imperial system, and use the Imperial system. As an engineer I accept that metric makes more sense, but when I read a metric dimension, I mentally convert the dimension to Imperial to visualize the size.

If I'm measuring a dimension that will need to be divided into halves or thirds, for example, my tape has both scales, so I use whichever one allows easier mental math.

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Old 16-11-2014, 06:28   #265
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Re: Convenience of the metric system

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I've just read the beginning of this thread, and the end of it.

But have to respond...mass is not weight.

FWIW, I grew up with the Imperial system, and use the Imperial system. As an engineer I accept that metric makes more sense, but when I read a metric dimension, I mentally convert the dimension to Imperial to visualize the size.

If I'm measuring a dimension that will need to be divided into halves or thirds, for example, my tape has both scales, so I use whichever one allows easier mental math.

And I really appreciate Mr. Whitworth.
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Old 19-11-2014, 10:50   #266
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Re: Convenience of the metric system

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Originally Posted by Wotname View Post
Imperial Question:
Which is heavier - an ounce[sp] of gold or an ounce of feathers?

Answer: an ounce of gold.


Metric Question:
Which is heavier - a kilogram of gold or a kilogram of feathers.

Answer: they both weigh the same.

So tell me which system is better for determining mass (weight).
This is a not very good joke, I hope ? Or maybe a trick question ?

As the buyer of several high end goose down sleeping bags over the years
I know from seeing the exact weights listed on invoices that an Imperial
ounce of goose down 850 that a ounce is a ounce no matter the product.

Fill power, loft ie. fluffiness, and insulating value is why one pays more for
1oz of 850 than 1oz of 700 goose down. As the mass of 850, in like conditions,
will be larger than that of the 700. As 850 fluff ie. mass is bigger ie. more than the 700 fluff.
And one pays more for the mass, not the weight. The weights being the same.

Mass and weight are not measured the same way.
To understand the differences we need to compare a few points:

1) Mass is a measurement of the amount of matter something contains,
while Weight is the measurement of the pull of gravity on an object.

2) Mass is measured by using a balance comparing a known amount of
matter to an unknown amount of matter. Weight is measured on a scale.

3) The Mass of an object doesn't change when an object's location
changes. Weight, on the other-hand does change with location.

Here's a better question IMHO.
If a cube has a mass of 90.91 kilograms and a weight of 200 pounds
on Earth, what will its mass and weight be on another planet?
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Old 19-11-2014, 11:06   #267
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Re: Convenience of the metric system

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If a cube has a mass of 90.91 kilograms and a weight of 200 pounds
on Earth, what will its mass and weight be on another planet?
Mass 90.91 kg,
Weight: 90.91*g in Newton, with g whatever the gravitational acceleration is on that planet.
:-)
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Old 19-11-2014, 11:44   #268
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Re: Convenience of the metric system

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This is a not very good joke, I hope ? Or maybe a trick question?

It was a trick question. Gold is normally weighed in Troy ounces rather than avoirdupois ounces. The convention though is to indicate Troy ounces.


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Old 19-11-2014, 13:07   #269
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Re: Convenience of the metric system

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This is a not very good joke, I hope ? Or maybe a trick question ?
Neither really although it is somethings used as a trick question. My point was how it is sometimes difficult using the imperial system to get real comparisons between products - more on that below.

Quote:
Originally Posted by Andrew B. View Post
As the buyer of several high end goose down sleeping bags over the years
I know from seeing the exact weights listed on invoices that an Imperial
ounce of goose down 850 that a ounce is a ounce no matter the product.
Not so with imperial measures. Your ounce of feathers is measured using an avoirdupois ounce (437.5 grains) while the ounce of gold is measured using a troy ounce (480 grains). Metric measures are 28.349523125 grams & 31.1034768 grams respectively.

Quote:
Originally Posted by Andrew B. View Post
Fill power, loft ie. fluffiness, and insulating value is why one pays more for
1oz of 850 than 1oz of 700 goose down. As the mass of 850, in like conditions,
will be larger than that of the 700. As 850 fluff ie. mass is bigger ie. more than the 700 fluff.
And one pays more for the mass, not the weight. The weights being the same.

I think you will find the mass of an ounce of these two products will be the same - you are confusing mass with volume in this instance. The loft relates to the uncompressed volume of the down.
Quote:
Originally Posted by Andrew B. View Post
Mass and weight are not measured the same way.
To understand the differences we need to compare a few points:

1) Mass is a measurement of the amount of matter something contains,
while Weight is the measurement of the pull of gravity on an object.
Yes
Quote:
Originally Posted by Andrew B. View Post
2) Mass is measured by using a balance comparing a known amount of
matter to an unknown amount of matter
. Weight is measured on a scale.

Mass can be measured by comparing the weight of the unknown matter to the weight and mass of the known matter at the same location. Mass is difficult to measure without using weight or without using volumes and densities. The balance method you suggest requires a gravitational force before it will work, so it also is measuring weight. Try using a balance in deep space - possible but very very difficult as the gravitational force to some very very distant galaxy is so weak as to almost meaningless.

Quote:
Originally Posted by Andrew B. View Post
3) The Mass of an object doesn't change when an object's location
changes. Weight, on the other-hand does change with location.
yes.
Quote:
Originally Posted by Andrew B. View Post
Here's a better question IMHO.
If a cube has a mass of 90.91 kilograms and a weight of 200 pounds
on Earth, what will its mass and weight be on another planet?
Will need to know the planet before determining the weight; mass will be 90.91 kilograms.
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Old 19-11-2014, 13:16   #270
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Re: Convenience of the metric system

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It was a trick question. Gold is normally weighed in Troy ounces rather than avoirdupois ounces. The convention though is to indicate Troy ounces.


Adelie
Certainly it is often a trick question although in this instance I was making a point about the inconvenience of the imperial system. I suggest most of us aren't aware of the two differing ounces.

Maybe it is the convention in your surroundings to indicate Troy ounces when discussing gold but it isn't in mine. I hear the gold price quoted daily just as ounces in the media. I go to the mint and buy a five ounce bar of gold and it is referred to as a 5 oz bar - maybe if I drilled down into the paperwork, there might be a mention of Troy but I haven't looked that deep.

I see gold mine reports of the number of ounces per tonne of ore and so on.
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