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Old 12-22-2009, 04:28 PM   #31
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Default Re: Trying out metric

With exception of repair of foreign-built models most of my work is in Imperial but I've learned to flit easily back and forth between the two systems by choosing to memorize .03937 and using that in transposing dimensions. That is also an exact number, derived from the inverse of 25.4. Most people seem to prefer the 25.4, and that's their choice, but for me the .03937 prooved to be more convenient and more intuitive. Either way, as someone said, it's simply a way to measure distance between two points. One thing that helped me get a better feel for length in metric was to buy a 12" (oops! 300mm) scale and keep it lying around on the on the bench for an occasional comparative measurement.


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Old 12-22-2009, 04:48 PM   #32
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Ah, it must be time for the annual Metric-Imperial fest again

The only thing I dislike about metric, well SI, to be pedantic, besides not being able to get stock or cutters or much of anything else easily in it here, is they didn't do a lot of human factors work before deciding on the core units. Yeah, they're fractions or multiples of some universal constant (or are now), but there's a reason inches, feet, pounds and so on evolved over time to be the way they are (and pecks and ells and hogsheads fell by the wayside)-- in the core "units", they're a convenient physical size for the task at hand.


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Old 12-22-2009, 05:52 PM   #33
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Default Re: Trying out metric

Excellent point, Shred.

One of the best examples of this is the Pascal, one Newton per square meter. It equates to 0.000145 psi, way too small to be useful.

However, as always, people will rearrange the system to their own comfort. Now widely used, though not, I believe, endorsed by SI is the 'bar' or 10^5 Pascal, which is a useful size and, coincidentally, almost equivalent to one atmosphere.

Most of these derived units are, however, simply related to the primary units so conversion simplicity is retained - unlike the Imperial system where they would have probably defined it as 5280 Pascal or somesuch nonsense.

I don't why the SI attempts to suppress the intermediate units (e.g., cm, dm, cc, cg). There doesn't seem to me to be any advantage and much disadvantage. Include them and exercise control over the inevitable derived units to keep the system usable.
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Old 12-22-2009, 08:18 PM   #34
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Default Re: Trying out metric

Quote:
Originally Posted by mklotz
I don't why the SI attempts to suppress the intermediate units (e.g., cm, dm, cc, cg). There doesn't seem to me to be any advantage and much disadvantage. Include them and exercise control over the inevitable derived units to keep the system usable.
Don't worry Marv,

I have a metric wife from a metric country and to measure anything cm is the only one used, e.g. 23 1/2 cm. I reckon it will never be suppressed as half the population refer to their dress, bust, waist, hip measurements etc. in cm.

We should be buying Newtons of potatoes but we buy by the kg; so if the boffins don't want their system misunderstood they need to go with the flow and as you say not impose unrealistic and sometimes meaningless terms/rules on an already confused transitional generation.

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Old 12-22-2009, 08:39 PM   #35
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Default Re: Trying out metric

Speaking of centimeters and the ladies...

The medical community still measures dilation of the birth canal in centimeters. Also, most syringes are calibrated in cubic centimeters.

Yes, Newtons of potatoes. At least the French had the good sense to not use the same unit name for force and mass.

Whenever I'm forced to deal with the Imperial system, I wonder, "Could they have possibly made it any worse?" I suppose the answer is yes, but I'm hard-pressed to understand how.

The astounding thing about the Imperial system is that its staunchest advocates don't understand it either. That explains why the USA will never adopt metric. If they did, they would have two measurement systems they don't understand.
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Old 12-22-2009, 09:01 PM   #36
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mm or cm here in Portugal, depends on the profession. Carpenters use cm, machinists use mm and when they talk "precision" they use 1/100th of a millimetre.
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Old 01-11-2010, 01:13 AM   #37
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Quote:
Originally Posted by mklotz


The astounding thing about the Imperial system is that its staunchest advocates don't understand it either. That explains why the USA will never adopt metric.
Americans will not adopt the metric system because they don't want to, not because it might be a better system or it would put the whole world under a unified measurement system. The more they think that metric is being forced on them the more they resist, generally if they didn't invent it they don't want it. To some of them accepting the Metric system is tantamount to announcing the arrival of the anti-Christ.

As for making the whole world unified under one measurement system, why should we, nothing else in the world is unified, different language, religion, money, government types, calendars, standards for the same things, etc, etc, etc.

The only way we can get the whole word onto one system is to throw out both the imperial and metric system and institute a new universal system that everyone will use, then we will all be the same, miserably unified.
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Old 01-11-2010, 03:15 AM   #38
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Quote:
Originally Posted by Loose nut
then we will all be the same, miserably unified.


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Old 03-05-2010, 01:20 AM   #39
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Default Re: Trying out metric

Quote:
Originally Posted by Loose nut
Americans will not adopt the metric system because they don't want to, not because it might be a better system or it would put the whole world under a unified measurement system. The more they think that metric is being forced on them the more they resist, generally if they didn't invent it they don't want it.
You already do use metric..............

How many cents in a dime and how many dimes in a dollar

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Old 03-05-2010, 09:03 AM   #40
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Default Re: Trying out metric

Only the BBC and dressmakers use cm, every one else uses mm up to 1,000 then it's metres.

Fractions are Ok but in 60 odd years of being around machine tools i have never seen a dial in fractions.

In imperial you have two measurements 31/64" is equal to 0.4844. Possibly a drawing says 31/64" but you have to turn or mill to 0.4844, room for error there.

In metric that measurement is 12.304, period, full stop, end of story, no room for error.

John S.


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