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why is the US not Metric
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mzzj:

--- Quote from: forrestc on November 11, 2019, 09:39:48 am ---

This is a good example of the effect of inertia on a measurement system.   Nuts and bolts in large commercial aircraft have traditionally been imperial, and there are lots of imperial-dimensioned parts that are certified to Aviation standards.   When Airbus started up, they elected to continue along the same path to avoid the costs of having different parts just for their aircraft.   So a European aerospace manufacturer is producing an aircraft that uses non-metric fasteners.

--- End quote ---
For some odd reason seatbelt mounting bolts are 7/16 20 TPI even on european cars.
bsfeechannel:

--- Quote from: TimFox on November 09, 2019, 03:23:29 pm ---"Yes, imperial and customary are a nightmare, because they use different bases, even within the same scale: 12 inches in a foot, 3 feet in a yard and 1790 yards in a mile."

Reply:  the US statute mile is 8 furlongs of 220 yards each, or 1760 yards.

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Thou, inch, foot, yard, chain, furlong, mile, league, fathom, cable, nautical mile, link, rod, different units for the same measurement: length. All of them with odd bases for the multiplication factors.

Metric has just one unit: the supreme METER, with just one base for factors: 10.

But then you have perch, rood, acre for area and fluid ounce, gill, pint, quart and gallon for volume.

Metric has... TA-DAAAA!: the supreme METER: m² and m³.
GeorgeOfTheJungle:
I don't know why, but I've always liked the units of measurement of the British Imperial System.
bsfeechannel:

--- Quote from: Rick Law on November 11, 2019, 01:10:09 am ---I have no explanation for 12 inch = 1 foot stuff.  My guess is, the King had in mind 16 inches to the foot, but one of his cronies was corrupt and always pocketed some of whatever the King bestows to the public, so he figure if the King want to give 16 inches to a foot, I'll pocket 4 inches for my own benefit, and gave the foot only 12 inches...
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The reason for the inch to be 1/12 foot is in the name of the unit. It comes from the Latin uncia, which means precisely one twelfth.

The Romans used base 10 for addition, multiplication and subtraction, and base 12 for division.

The Romans used base 10 for whole numbers and base 12 for fractions.


--- Quote ---Meter is not a natural unit.  it is an artificial construct just like a dollar or a euro.  What seem "the best unit to use" is based on common perspective and common familiarity within a culture (such as culture of say Chemist vs Civil Engineers vs Nutritionist vs...).   We now use 1/2 life of uranium (or any radioactive sample) instead of 1/10 life of uranium.  1/2 life is something scientist are comfortable with and have a mental gauge of how to apply that number.  We could switch to using 1/10 life of uranium, but what does that gain us?  None I can think of other than confusion.
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The meter can be adjusted to whatever scale you need. In metricated countries people use the meter to measure the diameter of a proton, the thickness of sheet metal, the length of a screw, the size of furniture, the dimensions of a property or a house, the distance between two cities, the size of the earth.

The metric system was thought out from the ground up for the modern world.
ciccio:

--- Quote from: bsfeechannel on November 11, 2019, 01:55:39 pm ---
The Romans used base 10 for addition, multiplication and subtraction, and base 12 for division.


--- End quote ---

Never heard this. It's interesting. Can you supply some reference? .
I studied Latin, more than 50 years ago, but I remember that division was done by series subctraction, using the standard notation, which can be assumed "base 10" or "base X"
Best regards
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