why is the US not Metric

[TimFox]

How lucky the humanity is by having electrical quantities in sensible units. Amperes, Farads, Volts, Ohms, Henries, etc. Except may be magnetics, with Webers and Teslas and who knows what. Imagine conversion from Sumerian Volts to Imperial Electrical Tension units. Oh and those Nepers (had to learn it recently).

Webers (Volt-second) and Teslas (W/m²) are perfectly sensible units in the same SI system as A, F, V, C, ohms, H, etc.
Things get unsensible when you mix cm and Gauss into magnetic calculations, where you have to change the fundamental equations.

[unitedatoms]

Yes the either Gauss or Tesla is redundant and confusing, do not remember well. And one of the reason I may not remember it well is that original confusion, when one learns and gets units introduced. On a subtle level the math involving retarded units break the will to think and learn. I believe the mechanical engineers insisting on imperial units suffer small daily loss of IQ from unnecessary fatique. 

[TimFox]

In electrodynamics, there is a “retarded potential” due to the finite speed of light, but the units are either “rationalized” (as are the SI units) or “unrationalized” depending on where you put 4 pi into the equations.  For electronics, I recommend sticking with rationalized SI units.

[Zero999]

That's funny, because in metric, the unit sizes make jumps by 10x, rather than 2x when dividing an inch into 2^-1 fractions. So if you like to use some unit that is say, about 3x as big as a centimeter, you might as well use the word inch. If you wanted something about a third the length of a meter, you might as well use a foot. Since they are already well defined. Esp if your country, which is the size of the entire EU, already uses them, consistently, as is the case for the US.

The same could be said about any unit. My little finger is about 1cm wide, so it's more convenient than inches and the distance between my finger tips and opposite shoulder is closer to a metre, than a yard, which comes in handy for measuring lengths of cable.

Interesting thought I discovered out of this thread. Of the native english speaking world, the US, alone, counts for near 3/4 of that figure. 2 billion people speak English. 400 million speak it as their first or lone language. About 300 million of these folks live in the US. The majority of english speakers around the world perhaps don't have much exposure to imperial units other than through media. Living in it is a different perspective, and it isn't even a thing to notice. Metric is just as useful to Americans, even if we don't feel an urgent need to buy butter in grams or to drive in km/h.

The beauty of SI units is they're independent of language. 1l of water is the same the world over: 1000cm³. The same isn't true for pints and gallons.

^ It would appear that someone in France wanted to make everything into 10's and 100's.

If that had caught on, we would be making right angles of 100 degrees/grads (a hectodegree?). Triangles would have 200 degrees/grads. Circles and polygons would add up to 400 degrees/grads.

A 45 degree angle would be 50. Considering the ubiquity of 30 and 60 degree angles in design and engineering and construction, these would now be 33.333 and 66.667 degrees.

An about-face or complete change in viewpoint/stance would be doing "a 200."    
In this base ten utopia, "K" and "100" could be applied and used to mean every other thing imaginable.

Well most scientific calculators have the option to enter degrees in gradians, although I've not used them myself.

Centimeters. Made by man in order to divide a circle into 400 degree. And so we can have these beauties:
https://www.123rf.com/photo_97469762_yellow-metric-measuring-tape-isolated-on-white-background.html

So if you are ok with stopping short on the grand Belgian plan and leaving 360 degrees in a circle, that's kinda how Americans feel about changing road signs and our daily parlance to metric. Yeah, that sounds nice. Just not for us.

The arguments for measuring angles in powers of 10, aren't as strong as distance, mass etc. because angles are really a fraction of a circle. The base unit is the turn, rather than a degree, which is ¹/₃₆₀ turns. We could divide a circle up into any arbitrary number, 360, 400, 24, 1024 etc. There's not so much of an advantage of multiplying by ten, as there is with other units of measurement. For example ¹/₈ turns is 50 gradians or 45 degrees: I don't see how either of those systems is easier to use than the other. 360 was probably chosen because it's possible to divide it by many different numbers, without going into decimals. Turns are often used for encoders, with the output being a binary fraction from 0 to nearly 1, so 10-bits would give 0 to ¹⁰²³/₁₀₂₄. I'd probably chose turns or milliturns, if I had to pick a unit for angles, but degrees are the most common.

[KL27x]

That's funny, because in metric, the unit sizes make jumps by 10x, rather than 2x when dividing an inch into 2^-1 fractions. So if you like to use some unit that is say, about 3x as big as a centimeter, you might as well use the word inch. If you wanted something about a third the length of a meter, you might as well use a foot. Since they are already well defined. Esp if your country, which is the size of the entire EU, already uses them, consistently, as is the case for the US.

The same could be said about any unit.

Not exactly. We really only have practical metric prefixes for every 3rd order of magnitude. The "short prefixes" of deci/deka/centi/hecto only work around a single base unit of meter and liter for distance and volume. Regarding mass, you have two base units being gram and tonne, which provides an additional nucleus for the short prefixes. You can have a dekagram. And you can have a dekatonne.

In imperial, you can apply these prefixes to inches, feet, yards, miles. That's all distance, and it doesn't even include furlongs and perches, yet, lol. In mass, you have  oz's or grains or lbs or short tons or long tons. In volume, you have ozs, cups, pints, gallons, barrels. Using centi/hekto/deka/deci with each of these units will produce a new range that might be useful for different things. In metric, you will have some gigantic gaps. 

Worse, as I showed earlier, the tools and/or industry standards can't always deal with these different prefixes. So you will use what you have. If your scale or caliper only displays in certain units, then that's what you choose from. Sometimes grams might be better. Sometimes grains. Sometimes milligrams. Depends what you are doing. No matter what you know in your head, the way you work will be affected by your available options when it comes to tools and standards.

Given all this, why are you so gungho about eradicating options other than metric?

My little finger is about 1cm wide, so it's more convenient than inches and the distance between my finger tips and opposite shoulder is closer to a metre, than a yard, which comes in handy for measuring lengths of cable.

Hence, where that is useful to you, you should use those units. There are some places where certain units might be useful due to the size of the units. There are places where units are useful due to legacy issues. And there are places where certain units are useful due to body of knowledge/standardization (e.g. how the mole is arbitrarily defined in grams by avagadro's number, and how 1L is standard amount of solvent for solutions). But in America, a lot of this is reversed; USC is still useful for many things, here, due to all 3 of these major reasons in addition to culture. So we use both systems.

The beauty of SI units is they're independent of language. 1l of water is the same the world over: 1000cm³. The same isn't true for pints and gallons.

I agree; this is why we (including Americans) love metric. Aussies use schooners and middys and pots, but this doesn't confuse anyone in Australia. You guys use pints and mph and stones, and no one gets confused over there. The fact we can describe any country/industry/custom unit in "the master system" called metric saves a lot of confusion.

I'd probably chose turns or milliturns, if I had to pick a unit for angles, but degrees are the most common.

"Milliturns" might be sliced bread for specific things. Grads might be great for certain things. But is it worth changing how airplanes navigate in order to switch to milligrees of lattitude and longitude? Is it worth retraining your artillery crew with new dope charts for distance and elevation and wind?* Changing geometry and scientific calculators to use 1000 milligrees for sin and cosine and tangent? To make a right angle 250? Do you have to "choose the best" and then use only one single system for every single function we perform using measurements? You will fix a lot of stuff that isn't broken; and you will introduce new problems just by sheer coincidence of seemingly innocuous differences that manifest in funny ways in specific applications, particularly where humans apply prior knowledge and experience and training. IOW, if the French artillery is hitting what they're supposed to, maybe let them keep using grads.

To many europeans, the answer appears to be a resounding "yes, as long as it's metric," let's just use one system for everything. To me, I rather understand math and ratios and relationships to get w/e I need out of w/e is already working exactly fine the way it is. And wherever human input is a factor, I would create a new unit if and where that helps humans to complete their task, even if the computer program under-the-hood is using metric or milligrees or grads or otherwise.

*I read somewhere that French artillery is done in grads; lest you think I'm obsessed with war or something.

[stefan_trekkie]

And again - Not exactly.
Machines that are build using metric only uses millimeters and kilos .. For example .. Bridge crane that is 22.5 meters LK is 22500mm in documentation .. And even most of the time is not specified .. Just digits and they are always milometers .. And kilograms too for the weight .. If something is in inches on the drawing (99% is some tread)  is noted  for example .. ½" 12 tpi .. Most of the metal piping here is in inches. Only the wood workers are using cm (centi meters  )

It is not very known but the base unit for the KG is "grav" (that means count) and the gram is 1/1000 of it ..  but after the French revolution they won't have that kind of ruler's title for unit and changed using gram .. kilogram - kg .. Witch is cube with side 100mm full of pure water on the sea level at the time.

I thing that the system that only uses 10ts as multiplier is very natural and simple to use. It is like capacitance on caps  X.10‾⁶ or MΩs X.10⁶ in practical calculations. Just moving the decimal point or adding 0s

It will be confusing to have 4-5 units with different names and they are close in ratios to one-another

[KL27x]

It will be confusing to have 4-5 units with different names and they are close in ratios to one-another

To an American, it isn't confusing, because Americans have had all these units since ever. It is consistently everywhere and it gets continuous usage and practice. Learning and using metric, in addition to our USC, is completely trivial.

Americans have already built a ton of culture, experience, tooling, tech, test equipment, engineering standards/practices, verbal and written communication/protocol/procedures/lingo around many of these english units. Accidentally losing any of this base of knowledge or tech/processes, as well as time/money lost in converting, is what should be scarier to a community/culture moreso than the fear of "I'm so confused, and now I need a calculator."

[GlennSprigg]

To date, there are 1017 Replies & 33469 Views to this post!! 
I can't absorb that many replies, so I'll just start with this...

Yes, the USA is big. They are entrenched in their ways. Will be a huge job to change!
However, they seem to forget their 'roots' !!  Unless I'm mistaken, it is the British who
first occupied their land. (Talking about real foreign influence, not the 'locals' at the time).
Since then, they have certainly gone off on their own 'tangent', as we have in Australia.

However, while they have become 'comfortable' in their own right, they keep re-inventing
the wheel!! And decided to have THEIR OWN version of the likes of a Ton, Gallon etc etc.
THAT has caused the most trouble when aligning themselves with the rest of the World.

Like it or not, the rest of the World has now gone Metric, and for a REASON. Standardization.
Most Americans don't realize that THEIR so-called weights-&-measures do NOT relate today
to standard physical entities that they think of. They are now scientifically related to METRIC units!

I understand their desire to 'hold-on' to what they know & like, mainly due to the difficulty of
change, but in the year 2020, in a Global environment, it makes no sense!! 
What could be simpler than DECIMAL, like your Dollars & Cents now !?  Where 1000 litres of
water is a metric Ton. And is also equal to a cubic Metre?? And 1 Ltr is 1 Kg...

This crosses paths with some WORDS that a lot of the USA likes to use, when they RE-Invent
how English words are sounded!!  (I'm just being pedantic & tongue in cheek here!!)...
The worst of the worst is... 'SOLDER'. If Americans invented the process, and gave it a name,
then GREAT. But they didn't! The English did, in regards to your carry-over use of the word.
The word is 'SOLder'. Not 'SODDer' with an invented silent 'L' 
(Colder, folder, holder, bolder, etc. No other exceptions).
And the Japanese cars are 'NISSan'. Not 'NEEsaan'. And Aussies are 'OZZies', not 'USies' 
Oh!!  And our Aussie model 'Elle McPherson' is 'McFERson', not 'McFEARson'   

People that know me, will understand my humor/digging in the last paragraph...
However, USA, you need to change. If not this decade, then WHEN !!   

[GeorgeOfTheJungle]

Unless I'm mistaken, it is the British who first occupied their land. (Talking about real foreign influence, not the 'locals' at the time).

Yes, you're mistaken... 

https://en.wikipedia.org/wiki/New_Spain

[CatalinaWOW]

 Where 1000 litres of water is a metric Ton. And is also equal to a cubic Metre?? And 1 Ltr is 1 Kg...

This relationship, which may have been repeated 100 times in this thread, is really useful.  When you are shipping fresh water or building fresh water tanks.  Which is hardly the key activity for this forum or in much of the rest of life.  And again gets to the point.  Other than standardization, which is a really big deal, and the elimination of the confusion between force and mass, the benefits of metric are minor. 

Dwellers in smaller markets feel the standardization pull more strongly than those in large markets.  The US remains (for the moment) the largest single market and so it is fairly obvious why the pull of standardization has been felt less strongly. 

[ebastler]

Just digits and they are always milometers ..

Aha -- I see a path towards "grand unification" there!!
Now add poundograms and Fahrengrade, and we can all be friends again. 

[TimFox]

 Where 1000 litres of water is a metric Ton. And is also equal to a cubic Metre?? And 1 Ltr is 1 Kg...

This relationship, which may have been repeated 100 times in this thread, is really useful.  When you are shipping fresh water or building fresh water tanks.  Which is hardly the key activity for this forum or in much of the rest of life.  And again gets to the point.  Other than standardization, which is a really big deal, and the elimination of the confusion between force and mass, the benefits of metric are minor. 

Dwellers in smaller markets feel the standardization pull more strongly than those in large markets.  The US remains (for the moment) the largest single market and so it is fairly obvious why the pull of standardization has been felt less strongly.

Please note that the definition 1 kg of water = 1 litre is for the benefit of chemists, who retained the old definition based on the maximum volume density of water.  The m³ is the SI unit for volume, and the litre is only approximately 1000 cm³, although the difference is very small.

[SkyMaster]

... 

Dwellers in smaller markets feel the standardization pull more strongly than those in large markets.  The US remains (for the moment) the largest single market and so it is fairly obvious why the pull of standardization has been felt less strongly.

The trade relationship of the United States with Canada is the second largest in the world, totaling $627.8 billion in 2016 (according to Wikipedia). The fact that United States is using United States customary units instead of the metric system, is the least of our worries.

Yet, there are people who never set foot in United States, and do not even deal with United States, but they want United States to adopt the metric system.

Could it be a form of envy toward United States?

 

[bsfeechannel]

Yet, there are people who never set foot in United States, and do not even deal with United States, but they want United States to adopt the metric system.

Who are those?

[ebastler]

the litre is only approximately 1000 cm³

Say what?! 

[KL27x]

GlennSpriggs of Australia:

I understand their desire to 'hold-on' to what they know & like, mainly due to the difficulty of change,

I would put it as the ease of using both. Even if the average American is a dummy that can't rationalize and use metric, we have plenty of jobs for this average dummy. For anyone in a job that involves engineering or physics, we rather that they can demonstrate proficiency in arbitrary systems. Having "a favorite" is fine, but keep it to yourself. Complaining about one or the other is seen as a mental deficiency.

The average citizen is an expert in ordering and drinking beers, for instance. In Australia, they created schooners and middys for the ease of performing this repetitive task. In American, we have many such repetitive tasks in manufacturing and construction. Do you want a oil line to pump 20% more oil? Exxon engineers will use their existing body of knowledge and make the new one with imperial units.

I understand their desire to 'hold-on' to what they know & like, mainly due to the difficulty of
change, but in the year 2020, in a Global environment, it makes no sense!! 

What is the difference in "Global environment" today and during the 1800's? We are all friends, now, and should settle disagreements with chess matches, because we have the internet? We started 2020 by blowing up Iran's top general with supersonic drone missiles. But let's all get on the same page with the cups and quarts?

However, they seem to forget their 'roots' !!  Unless I'm mistaken, it is the British who
first occupied their land. (Talking about real foreign influence, not the 'locals' at the time).

Americans are not ashamed of their culture and history. The imperial system has roots going back millennia, all the way to the cradle of civilization, in the area before Iran existed. The Brits and Americans have actually butchered this system a bit since the roman era.

[bsfeechannel]

Dwellers in smaller markets feel the standardization pull more strongly than those in large markets.  The US remains (for the moment) the largest single market and so it is fairly obvious why the pull of standardization has been felt less strongly.

This brings the thread to a full circle. The world is economically 5 times greater than the US. Its population, minus the US, is at least 20 times greater.  The world has a road network that is about 9 times lengthier than the US's. The world's GDP per capita is $17,300  (including the US), while the US GDP per capita alone is $60,000.

So the world, with more roads, greater population, bigger economy, but less money per capita, managed to successfully go metric. Why can't the US with much more favorable conditions do so?

Is it because the US has a culture and a knowledge base around imperial that it can't afford to suddenly ditch? But what about the rest of the world? Didn't they have a previous culture and knowledge base around their customary units? What made abandon all of that in favor of metric?

[KL27x]

Is it because the US has a culture and a knowledge base around imperial that it can't afford to suddenly ditch? But what about the rest of the world? Didn't they have a previous culture and knowledge base around their customary units? What made abandon all of that in favor of metric?

Yes. Many other cultures/nations have historically had relatively little to preserve in comparison to the US in this aspect. This is partly because America was one of the world leaders of technological advancement from the late 1800's to today. Significant portion of this boon occurred before America even had access to metric prototypes, being on the wrong side of the globe. The foundation for a lot of today's tech was laid out in inches, in America. And the reason this worked is because America used consistently sized feet and inches across its borders. They had that sorted out from the beginning of this boon. Russia's system was a complete mess until the change over to metric.

We were also in a tech race against the Axis and then the Soviet Union for many decades, post WWII.

This has already been discussed many times in this thread, but you are intentionally blind to anything that doesn't fit your narrative.

Secondly, you assume all other countries other than US and Myanmar have voluntarily abandoned their customary measures in order to "get the most" out of metric, when in fact most of the globe changed to metric during regime changes that destroyed other parts of national culture and government. And even then, there is still use of traditional measuring systems in many countries besides the US.

[ebastler]

Many other cultures/nations have historically had relatively little to preserve in comparison to the US in this aspect. This is partly because America was one of the world leaders of technological advancement from the late 1800's to today. Significant portion of this boon occurred before America even had access to metric prototypes, being on the wrong side of the globe. The foundation for a lot of today's tech was laid out in inches, in America.

This pride and preservation of technological heritage worked particularly well for the Detroit car industry. 

Well, I won't grin too broadly, since the next years will show whether the German car industry can avoid falling into the same trap...

[SilverSolder]

Many other cultures/nations have historically had relatively little to preserve in comparison to the US in this aspect. This is partly because America was one of the world leaders of technological advancement from the late 1800's to today. Significant portion of this boon occurred before America even had access to metric prototypes, being on the wrong side of the globe. The foundation for a lot of today's tech was laid out in inches, in America.

This pride and preservation of technological heritage worked particularly well for the Detroit car industry. 

Well, I won't grin too broadly, since the next years will show whether the German car industry can avoid falling into the same trap...

All Detroit cars have metric fasteners these days (and have had for many decades now).  Any American car guy will know his Metric wrench sizes...

[KL27x]

Well, the US car industry, including GM/Detroit, has been totally metric since the late 80's or maybe mid 90's. But nice try.

America has given up the car industry. America is putting all the subsidy into the MIC, oil/energy, and farming. The value of cars does not skyrocket in times of need. But life? The margins are only limited by how much you need to live at any given time.

[SilverSolder]

[...]
America has given up the car industry.
[...]

GM is one of the top 3 auto makers in China...   -  the US car industry not going away anytime soon.

[ebastler]

Well, the US car industry, including GM/Detroit, has been totally metric since the late 80's or maybe mid 90's. But nice try.

Right, but the the industry went downhill before that, in the 70s and 80s, when they had missed the boat on "novel" ideas like fuel economy, decent suspensions and whatnot.

I didn't mean to imply that not being metric was the cause the for the US car industry's downturn; that cause was being too internally focused and blind to progress made abroad. But the exclusive use of the imperial system at that time can be seen as a symptom of that unhealthy internal focus. And likewise, the subsequent adoption of the metric system may be one indication of an increased openness to international competition and ideas, but not the root cause for the (slight) recovery of the car industry.

[KL27x]

As an average American, I would venture the reason for the American car industry to fall off is just natural competition and the relatively lower priority of the US to subsidize this industry due to lower profit potential. Air/energy/food/weapons, OTOH, are in high demand anywhere the average citizens start becoming unhappy with their leadership/government. And/or threats from expansionist neighbors.

Competitive markets are great and all, but you can make a lot more money, power, and influence if you have an edge if not a monopoly in industries where the price tags are almost irrelevant when they are needed.

Is this a good long-term strategy? Compared to China, where they subsidize steel and general manfucaturing and infrastructure with similar amount of resources what US spends on defense industry?Who knows. But that's where we are, and we'll find out in another 100 years.

Edit: also, during the 80's and 90's Japan basically kicked everyone's ass at making engines. There was a good decade where they shook things up and took the lead. This really didn't have anything to do with metric or imperial, AFAIK.

[tooki]

Well, the US car industry, including GM/Detroit, has been totally metric since the late 80's or maybe mid 90's. But nice try.

Right, but the the industry went downhill before that, in the 70s and 80s, when they had missed the boat on "novel" ideas like fuel economy, decent suspensions and whatnot.

I didn't mean to imply that not being metric was the cause the for the US car industry's downturn; that cause was being too internally focused and blind to progress made abroad. But the exclusive use of the imperial system at that time can be seen as a symptom of that unhealthy internal focus. And likewise, the subsequent adoption of the metric system may be one indication of an increased openness to international competition and ideas, but not the root cause for the (slight) recovery of the car industry.

Nah, that’s not really it.

The US auto industry was complacent, but you also have to remember that totally different market forces were at play in USA. They’d had cheap fuel for ages, and that changed suddenly. In contrast, Europe and Asia had had expensive fuel for a long time by then, so they’d adapted to that already.

The other thing, the really big one, was management structure. Toyota (the singular leader in auto management at the time) was much more agile, so they could release a new model in far less time. And their quality management led to ongoing improvement so that bad parts, and thus bad cars, never made it out, whereas the US automakers were letting subpar product slip through. (And the Germans were manufacturing just as poorly as the Americans, except that then they’d spend enormous amounts of time on corrective rework, under the guise of “craftsmanship”.)