The US Plans to Finally Standardize the Length of a Single Foot(99percentinvisible.org)
99percentinvisible.org
The US Plans to Finally Standardize the Length of a Single Foot
https://99percentinvisible.org/article/goofy-feet-the-us-plans-to-finally-standardize-the-length-of-a-single-foot/
68 comments
For clarity (since the article doesn't make it clear), there are two "standard" definitions of the units. Is the inch exactly 2.54 cm [the standard international foot], or is the yard exactly 39.37 cm [the US survey foot]?
These two definitions are off by 2ppm. For all intents and purposes, they are the same. If you measured the distance between San Francisco and New York City, the error in measurement between these two definitions would be between 8 and 9 meters.
These two definitions are off by 2ppm. For all intents and purposes, they are the same. If you measured the distance between San Francisco and New York City, the error in measurement between these two definitions would be between 8 and 9 meters.
> Is the inch exactly 2.54 cm [the standard international foot], or is the yard exactly 39.37 cm [the US survey foot]?
Wait...if a yard is 39.37 cm than a foot is 12 1/3 cm, which would make an inch 1 1/36 cm. That's off from 2.54 cm by way more than 2 ppm!
A yard would be exactly 91.44 cm if the inch is 2.54 cm, and something very very close to that if it is 2 ppm from the "inch is 2.54 cm" yard.
Did you copy/paste the wrong thing? A survey foot is 1200/3937 meters (making a yard ~91.44018288 cm), so 3937 would probably be floating around somewhere on any page talking about this.
Wait...if a yard is 39.37 cm than a foot is 12 1/3 cm, which would make an inch 1 1/36 cm. That's off from 2.54 cm by way more than 2 ppm!
A yard would be exactly 91.44 cm if the inch is 2.54 cm, and something very very close to that if it is 2 ppm from the "inch is 2.54 cm" yard.
Did you copy/paste the wrong thing? A survey foot is 1200/3937 meters (making a yard ~91.44018288 cm), so 3937 would probably be floating around somewhere on any page talking about this.
You're right--it should have been a meter is exactly 39.37 inches.
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Previous stories on HN. "America Has Two Feet. It’s About to Lose One of Them" (21c):
* https://news.ycombinator.com/item?id=24196228
"Ending the Era of the U.S. Survey Foot" (158c):
* https://news.ycombinator.com/item?id=22203919
On the somewhat-related topic of measuring things, interesting book by Simon Winchester called The Perfectionists:
> The rise of manufacturing could not have happened without an attention to precision. At the dawn of the Industrial Revolution in eighteenth-century England, standards of measurement were established, giving way to the development of machine tools—machines that make machines. Eventually, the application of precision tools and methods resulted in the creation and mass production of items from guns and glass to mirrors, lenses, and cameras—and eventually gave way to further breakthroughs, including gene splicing, microchips, and the Hadron Collider.
[…]
> As he introduces the minds and methods that have changed the modern world, Winchester explores fundamental questions. Why is precision important? What are the different tools we use to measure it? Who has invented and perfected it? Has the pursuit of the ultra-precise in so many facets of human life blinded us to other things of equal value, such as an appreciation for the age-old traditions of craftsmanship, art, and high culture? Are we missing something that reflects the world as it is, rather than the world as we think we would wish it to be? And can the precise and the natural co-exist in society?
* https://www.goodreads.com/book/show/35068671-the-perfectioni...
* https://news.ycombinator.com/item?id=24196228
"Ending the Era of the U.S. Survey Foot" (158c):
* https://news.ycombinator.com/item?id=22203919
On the somewhat-related topic of measuring things, interesting book by Simon Winchester called The Perfectionists:
> The rise of manufacturing could not have happened without an attention to precision. At the dawn of the Industrial Revolution in eighteenth-century England, standards of measurement were established, giving way to the development of machine tools—machines that make machines. Eventually, the application of precision tools and methods resulted in the creation and mass production of items from guns and glass to mirrors, lenses, and cameras—and eventually gave way to further breakthroughs, including gene splicing, microchips, and the Hadron Collider.
[…]
> As he introduces the minds and methods that have changed the modern world, Winchester explores fundamental questions. Why is precision important? What are the different tools we use to measure it? Who has invented and perfected it? Has the pursuit of the ultra-precise in so many facets of human life blinded us to other things of equal value, such as an appreciation for the age-old traditions of craftsmanship, art, and high culture? Are we missing something that reflects the world as it is, rather than the world as we think we would wish it to be? And can the precise and the natural co-exist in society?
* https://www.goodreads.com/book/show/35068671-the-perfectioni...
It is kind of annoying. In my job we have to use both all the time. Schematics will sometimes use both in a single drawing! Metric may not be ideal -- I appreciate the English system for it's ease of halving, but it still would be better if there was a single standard.
Why is it easier to halve with the imperial(I assume that's what you mean by 'English') system? Could you give an example?
imperial distance units are related by 12. 12 inches in a foot. 12 (* 440) feet in a mile. 12 has more integer divisors than 10, so it is more likely that you end up with whole units when you apply simple ratios. it's not a big advantage in the age of digital calculators, but it arguably makes day-to-day calculations easier.
but to answer your question, I don't think imperial distance units have an advantage with halving. 1 m / 2 = 50 cm, and 50 cm / 2 = 25 cm. no less straightforward than 1 ft / 2 = 6 in, and 6 in / 2 = 3 in. either way we can't go further without creating a fraction. imperial distance has a clear advantage with thirds. 1 ft / 3 = 4 in, but 1 m / 3 is unrepresentable as a decimal number.
of course none of this applies to imperial volume units which are related by various powers of two. these are much easier to halve, but do not have the advantage with thirds.
but to answer your question, I don't think imperial distance units have an advantage with halving. 1 m / 2 = 50 cm, and 50 cm / 2 = 25 cm. no less straightforward than 1 ft / 2 = 6 in, and 6 in / 2 = 3 in. either way we can't go further without creating a fraction. imperial distance has a clear advantage with thirds. 1 ft / 3 = 4 in, but 1 m / 3 is unrepresentable as a decimal number.
of course none of this applies to imperial volume units which are related by various powers of two. these are much easier to halve, but do not have the advantage with thirds.
Leetcrew is right, but the advantage is greater.
Inches are typically divided in powers of two. So you don’t have to represent the 5 digitally when dividing (which you can’t in the binary system).
So, if the basic unit you’re designing with is inches, you can scale up easily and add a 3 with the base 12. Or divide using only 2 which helps the computer out
Inches are typically divided in powers of two. So you don’t have to represent the 5 digitally when dividing (which you can’t in the binary system).
So, if the basic unit you’re designing with is inches, you can scale up easily and add a 3 with the base 12. Or divide using only 2 which helps the computer out
But halving is made easier because people say things like “3/8 of an inch”, no? If that’s all, nothing prevents you from using expressions like “3/8 of a cm”. If, on the other hand, 2 (or say 4) inches equaled 1 foot, 2 feet 1 yard, etc...
> nothing prevents you from using expressions like “3/8 of a cm”.
I'm going to use that with one of my European colleagues. And watch their eyes cross as they try to make sense of it.
I'm going to use that with one of my European colleagues. And watch their eyes cross as they try to make sense of it.
Yeah well in the rest of the non english world we also have to fight with multiple charsets for simple things such as excel exports and you have no idea the amount of time and money this just cost.
I think it s better than 200 years ago for sure, but we need to continue merging all standards or we suffer for nothing forever.
I think it s better than 200 years ago for sure, but we need to continue merging all standards or we suffer for nothing forever.
It's all nice and swell (you can also cut in 3 fairly easily with imperial) until someone has to calculate the volume of a swimming pool given it's three dimensions (or launch a non-exploding space shuttle).
This is an issue in GIS and when you get it wrong, you can find your map sticks things in the middle of the street instead of on the sidewalk where they really are.
[deleted]
why not combine the both and adopt the metric inch?
Because the inch is already metric. Has been for 100 years.
1 in == 25.4 mm
Therefore US customary units, while not being SI, are just as metric units as the calorie (energy to raise one (metric) gram of water one (metric) degre C.
Switching to metric doesn’t have too many advantages - learn the bloody definitions - but has trillions of dollars of disadvantages (think the capital in machining tools. Now add the cost of training the old guys to metric)
In fact the imperial system has some advantages over metric: the measures are often divided by powers of 2, meaning they can be better represented in binary.
Also, there are some very fun quirks with the imperial system that I love:
1 in == 2.54 cm = 2^8 /100 cm. Very useful if you need to convert from a 64th of an inch.
1 mi ~ phi km. Also very cool.
And then all the history behind those beautiful, since forgotten, customary units.
[im a European-Canadian who moved to the US as an adult; trained on metric my whole life]
1 in == 25.4 mm
Therefore US customary units, while not being SI, are just as metric units as the calorie (energy to raise one (metric) gram of water one (metric) degre C.
Switching to metric doesn’t have too many advantages - learn the bloody definitions - but has trillions of dollars of disadvantages (think the capital in machining tools. Now add the cost of training the old guys to metric)
In fact the imperial system has some advantages over metric: the measures are often divided by powers of 2, meaning they can be better represented in binary.
Also, there are some very fun quirks with the imperial system that I love:
1 in == 2.54 cm = 2^8 /100 cm. Very useful if you need to convert from a 64th of an inch.
1 mi ~ phi km. Also very cool.
And then all the history behind those beautiful, since forgotten, customary units.
[im a European-Canadian who moved to the US as an adult; trained on metric my whole life]
When I was in school, the inch was 2.54005 cm. And I am somewhat less than 100 years old.
When was the inch defined as 2.54 cm? It was within my lifetime, but I don't recall the year.
[Edit: Looks like 1959, which is slightly before my time. It takes a bit for textbooks to catch up...]
When was the inch defined as 2.54 cm? It was within my lifetime, but I don't recall the year.
[Edit: Looks like 1959, which is slightly before my time. It takes a bit for textbooks to catch up...]
It’s actually earlier than that, it took standard committees decades to catch up to industry.
The 2.54 cm inch was effectively imposed by Johansson’s gauge blocs back in 1912. The Brits accepted it as the standard in 1930, the American Standards Assoc. in 1933.
The 1950s date you cite is when government finally caught up.
Edit: (Gauge blocks are super cool, btw)
The 2.54 cm inch was effectively imposed by Johansson’s gauge blocs back in 1912. The Brits accepted it as the standard in 1930, the American Standards Assoc. in 1933.
The 1950s date you cite is when government finally caught up.
Edit: (Gauge blocks are super cool, btw)
[deleted]
Why don't they just go to the logical next step and just make metric the standard, the Imperial System (foot etc.) are already defined by the Metric system?
Humorous view on the situation: https://www.youtube.com/watch?v=hid7EJkwDNk
Humorous view on the situation: https://www.youtube.com/watch?v=hid7EJkwDNk
Metric is currently the “ preferred system of weights and measures for United States trade and commerce”
https://uscode.house.gov/view.xhtml;jsessionid=8314B6B7A95CC...
As you mentioned, the foot and all other U.S. customary units are based on the International System of Units (SI).
https://www.nist.gov/pml/weights-and-measures/metric-si
https://uscode.house.gov/view.xhtml;jsessionid=8314B6B7A95CC...
As you mentioned, the foot and all other U.S. customary units are based on the International System of Units (SI).
https://www.nist.gov/pml/weights-and-measures/metric-si
The biggest historical reason for the current state of affairs is that metrification largely came with industrialization, but in the US industrialization had already happened with US customary units and industrialists resisted the change. Or that’s how I understand it.
There are largely tangible benefits using imperial over metric, builders arithmetic is much easier for one, it's all fractions based.
I m not sure I get that. You can subdivide metric as well, and we build a lot of things in China, Japan, Germany, England, France, Australia, us metric system users.
It seems that the US, Myanmar and Liberia, the current users of the imperial system, could join us with minimal or negligible cost.
It seems that the US, Myanmar and Liberia, the current users of the imperial system, could join us with minimal or negligible cost.
I think what they are trying to say is all the building materials and measuring tapes are designed with halves quarters, eighths, etc. in mind. But obviously that could have been done in metric too. But 2 and 5 are the only common factors in metric. 12 inches in a foot means 2 3 and 5. 5280 feet in a mile is similarly dividable. One of the reasons metric time never took of was because we have more factors in 60 and 24 than in 10.
> It seems that the US, Myanmar and Liberia, the current users of the imperial system [...]
Nitpick: That's wrong. Neither the US, nor Myanmar use the imperial system.
The US uses US customary units, while Myanmar uses traditional Burmese units of measurement. Neither of which are imperial units (as defined by the British Weights and Measures Act) and only US customary units are related to the imperial unit system.
Nitpick: That's wrong. Neither the US, nor Myanmar use the imperial system.
The US uses US customary units, while Myanmar uses traditional Burmese units of measurement. Neither of which are imperial units (as defined by the British Weights and Measures Act) and only US customary units are related to the imperial unit system.
The cost isn’t that minimal when everyone has materials denominated in customary units anyway, tool sets in them, and so on, and the benefit isn’t that big when the industrial and scientific applications that really would most benefit are already done in metric.
At risk of asking a stupid question, why is that easier than moving a decimal point around?
It’s much easier to cut something in half and half again, to get 0.25 then it is to cut something in fifths to get 0.2, for example. So if you’re a proficient carpenter you have all sorts of tricks and geometrical constructions that let you work quickly without necessarily making a precision measurement or taking out a measuring tape.
Imperial gets tricky real quick as soon as you need to mix additions/subtractions with multiplication/division which happens surprisingly often in building.
eg: imagine you have a 5 & 1/2 foot cabinet with 4 equal sections framed out with 3/4" boards, what is the height of each section? It's (5 & 1/2' - (5 * 3/4")) / 4 which I guarantee nobody is working out in their head easily.
eg: imagine you have a 5 & 1/2 foot cabinet with 4 equal sections framed out with 3/4" boards, what is the height of each section? It's (5 & 1/2' - (5 * 3/4")) / 4 which I guarantee nobody is working out in their head easily.
Metric system or Imperial system; we could all benefit if we, humans, had 12 fingers!
Decimal system isn’t our finest legacy. If we had to go back in time, we’d change history by choosing duodecimal system from the get go.
https://en.wikipedia.org/wiki/Duodecimal
Decimal system isn’t our finest legacy. If we had to go back in time, we’d change history by choosing duodecimal system from the get go.
https://en.wikipedia.org/wiki/Duodecimal
Senary seems most optimal.
The level of precision offered by that is too high for just one-man woodwork or something, I guess is the point.
How so?
You can divide a foot in half, thirds, quarters, sixths, eighths, etc and the divisions will all end up exactly at a mark on your ruler or tape. Most of these can be subdivided again and again because the ruler is marked in 1/2, 1/4, 1/8, and 1/16 divisions, rather than powers of ten.
You can add any kind of divisions in the ruler, not matter what unit you use.
It's just a historical curiosity.
Metric rulers just don't use those because there is tradition of using different fractions. In metric you typically use: 1, 3/4, 6/8, 5/8, 1/2, 3/8,1/4, 1/5, 1/8, 1/10, 1/20, 1/25, 1/50, 1/100...
Metric rulers just don't use those because there is tradition of using different fractions. In metric you typically use: 1, 3/4, 6/8, 5/8, 1/2, 3/8,1/4, 1/5, 1/8, 1/10, 1/20, 1/25, 1/50, 1/100...
I've never actually seen a "metric" ruler with non-decimal divisions, but that would work.
People go the other way too--some American machinists work in 'mils' (=1/1000 of an inch), since one often wants (and can achieve) that kind of precision.
People go the other way too--some American machinists work in 'mils' (=1/1000 of an inch), since one often wants (and can achieve) that kind of precision.
This video goes over the failures of the UK, US, and Canada switching to Metric (from the perspective of a Canadian) https://www.youtube.com/watch?v=s95cxZkC_es
While I agree that Metric is better, converting isn't very practical. Imagine the cost of having to change every sign, book, and other text using imperial measurements, as well as any programs and tools that are based on imperial. It just wouldn't happen.
We could pass a law saying "we're metric now", but it would likely just be a formality while we continue using Imperial.
We could pass a law saying "we're metric now", but it would likely just be a formality while we continue using Imperial.
You don’t have to change everything all at once. Make new things use both. Then later make new things use metric only. Maybe. In the UK milk comes in multiples of a pint but with millilitres shown on the packaging too.
Things that are all possible and payable in every country on the planet, poor or rich, except the US of A
I wonder which country of the mighty triumvirate of USA, Liberia and Myanmar would be the first to leave this club.
Plenty of other countries still use “foot” as a measurement. Try asking a Canadian or Brit how tall they are in cm
Canadians still use the imperial system personally but the country is metricized. We’re just stuck with paper and wood in inches because we’re next to the US.
It's on the way out, but in Ireland people are colloquially weighed in stones, sheep in kgs and feed in lbs. For a while, speed and distance weren't compatible.
Metric money was a similar issue in the 60s. People still thought in shillings for decades. I read that historically (especially in Britain) entirely different counting systems were used simultaneously. Shepherds had their sheep counting numbers, sailors had a different one.
Dialects ran deep, not long ago.
Incidentally, it's lucky that metric never became known as "The French System."
Metric money was a similar issue in the 60s. People still thought in shillings for decades. I read that historically (especially in Britain) entirely different counting systems were used simultaneously. Shepherds had their sheep counting numbers, sailors had a different one.
Dialects ran deep, not long ago.
Incidentally, it's lucky that metric never became known as "The French System."
There are a lot more similarly arbitrary things than just paper and wood which are measured in imperials in Canada.
I'm reminded of this (comical) guide I first saw posted on Reddit: https://www.reddit.com/r/coolguides/comments/e1hx4f/how_to_c...
I'm reminded of this (comical) guide I first saw posted on Reddit: https://www.reddit.com/r/coolguides/comments/e1hx4f/how_to_c...
Speaking as a Canadian mechanical engineer: pretty much all raw materials. Metal bars, beams, sheet and plates, etc. Wire in AWG. Cutting tools for machining are also way more common in inch sizing.
At least metric fasteners are becoming common enough that I can use almost 100% in my designs.
At least metric fasteners are becoming common enough that I can use almost 100% in my designs.
[deleted]
In Britain we overwhelming use metric in business, construction, industry or science. Things like feet for height still have resonance but more in a cultural way than practical.
I think most British people under 40 would measure height in cm, so it’s dying out.
I can tell you (I'm English) and i would expect most people can (with those preferring feet skewing older of course).
The only "in your face" use of imperial is speed limits. Maybe one day that will get fixed.
The only "in your face" use of imperial is speed limits. Maybe one day that will get fixed.
I think they should switch to m/s. Seems far more intuitive as a way of understing speed.
Going 30 down the highway. Roflmao.
Edit, hey this actually works out quite well, 1 for walking speed in parking lots and 15 round town.
Though I do think going the other way might be better. 3000 down the highway.
Edit, hey this actually works out quite well, 1 for walking speed in parking lots and 15 round town.
Though I do think going the other way might be better. 3000 down the highway.
Myanmar doesn't use imperial units or US customary units.
They use traditional Burmese units. Non-metric doesn't equal imperial/US customary.
They use traditional Burmese units. Non-metric doesn't equal imperial/US customary.
It is not a club of countries who use imperial units. It is a club of countries that do not use metric system.
Btw before the coup Myanmar seemed to be on a path to finally convert to metric system, but now I think they have bigger issues to worry about.
Btw before the coup Myanmar seemed to be on a path to finally convert to metric system, but now I think they have bigger issues to worry about.
[deleted]
Might I recommend they standardize on 39.3701 inches ?
I've always understood 1 foot = 12inches = 25*12mm = 30cm
This is like polishing a turd and put it on display.
New plan:
1in = 2.5cm
1ft = 3dm
1yd = 9dm
1mi = 16092dm
I'm not sure whether it would be more or less likely than eliminating imperial units entirely :/
(edit: This wasn't entirely snark. For reference: the circumference of the earth is ~24901mi. With the new measure it would be ~24903mi, which isn't too shabby)
1in = 2.5cm
1ft = 3dm
1yd = 9dm
1mi = 16092dm
I'm not sure whether it would be more or less likely than eliminating imperial units entirely :/
(edit: This wasn't entirely snark. For reference: the circumference of the earth is ~24901mi. With the new measure it would be ~24903mi, which isn't too shabby)
Specifically, my left foot. It's more annoying than you'd think: I've had people in and out of my apartment with rulers for weeks, and taking my shoes on and off all the time is a hassle. I finally sent them all packing when someone showed up with a hand saw and an anesthesiologist.
https://www.nist.gov/pml/us-surveyfoot
To be clear, the 'foot' used in day to day use has already been standardized to the international foot. It's only in surveying where there's weirdness, and that's what this is resolving in.