> The problem with these versions is that they don’t explain why this collision between furlong and mile occurred around 1600, and not centuries before. It implies, therefore, that people suddenly woke up and realized, hey, wait a second, if there’s 660 feet in a furlong … and eight furlongs in a mile … but 5000 feet in a mile …. wait a second !?!
It's not that hard to guess why the broken system lasted so long (delightful and interesting explanation of TFA notwithstanding), and consequently why it was replaced by a different broken system.
95% of people on this planet use, understand, and advocate metric, in which an area of 100 metres x 100 metres = 1 hectare (10,000 sq m).
A 10 x 10 grid of hectares = a square kilometre.
A millimetre of rain falling across one hectare means you've received 10,000 litres of water.
That volume of water has a mass of 10,000 kilograms (or 10 tonne).
A Bernard Cornwell novel about king arthur introduced me to all sorts of defunct, proto-english & welsh counting systems. Shepards used one system. Sailors used another. Soldiers another. It was part of a society that was deeply dialectic in all things, especially language.
This resonated with me, because my grandfather had sheep. Sheep were weighed in kgs. People were weighed in stones. Feed in pounds. Sheep were sold in dozen and half-dozen dividable lots. Land in acres. In his region, one acre could feed one cow and one sheep so they had an intuitive serendipity. 100 acres made a viable farm.
Measurement systems tend to leave even more vestiges than other elements of language. Most of the world uses metrics, but almost no one advocates for metric time or angular units. Square kms never became an agricultural measure of land because one is bigger than most farms. Instead, metric hectares and metric dunams were adapted to be metric. They were close enough. Acres weren't, so there is no metric acre.
There are sixty minutes in an hour and 360 degrees in a circle because sumerians used a base 60 numerical system 5 thousand years ago. I have never even heard of a metric angular unit.
I totally accept the fact that metric systems are better. Engineering anything in inches seems impossible. OTOH, the richness and embedded history of language is valuable too. There's a reason esperanto never caught on, even though it's arguably the right tool for the job.
> Sheep were weighed in kgs. People were weighed in stones. Feed in pounds.
The reason you can get away with this for so long is because you -- historically, especially -- almost never need to convert between "mass of feed" and "mass of sheep" and "mass of people". Even for the most common case where it would matter (transporting each of the above) it almost doesn't, because you typically use different vehicles for each purpose.
This means most people who deal with non-metric units almost never run into the friction of mixed units -- if you're doing carpentry, for instance, everything is inches, from lumber to doors to room dimensions, so you almost never actually have to deal with multiplying or dividing by 12 to convert to feet.
Likewise with there being 5280 feet in a mile. Sure, if you actually have to convert from feet to miles, it's a pain and a potential source of error. But why the heck are you converting from feet to miles? Pick whichever unit makes sense for the task and hand and stick with it.
Those are really good points, except maybe converting between masses. At some point or another you have to transport stuff. If you send a wagon with 3 tons of feed on it to a farm, how many sheep can you send back to town for sale? That goes double if a ship or boat is involved.
Secondly, the answer is: a wagon-full. Sheep are not particularly more dense than grain. You are not going to be able to cram a higher mass of sheep in a wagon than you can cram grain; the exact number you could transport in a particular wagon will be determined more by geometry than mass.
This does tend towards a common mass-unit for anything that is shipped by mass; in archaic American/English units this is typically the hundredweight and ton, depending on whether you are shipping a little or a lot.
A more likely example would be shipping grain or coke one way and shipping iron stock back; you might transport 15 hundredweight each way, although more likely you'd be light one way or the other.
> Instead, metric hectares and metric dunams were adapted to be metric
Ares (and therefore hectares) aren't part of the SI system, but they are original metric units -- an are is 10m×10m, hect- is the prefix meaning 100×.
The metric angular unit is a gradian. I've heard of it, as I read the whole manual when I first had a scientific calculator, age 11-ish, but I've never worked in a field where it's used.
Pedantically, the SI standard[1] defines the term "radian" as a "special name[] for the number one that may be used to convey information about the quantity concerned."
The gradian was the original metric angle unit, before it was replaced by the radian in SI because the powers that were decided that pi was more important than base 10, as the standard prefixes are nearly useless for angular measure.
People would love to but there are some nasty fractions left over if you try to impose a base 10 unit of time at any level above a day.
Any metric time system stumbles on the fact that 1) Days do not even divide into years by 10 and there's not even a whole number of days in a year and 2) calendars should sync with the seasons to provide any real use.
Also 10 days to a week is pretty long unless you include a break in the middle.
Vernor Vinge's excellent novel A Deepness In The Sky, which is mostly set aboard spacecraft disconnected from planetary time cylces, uses metric measurements of time (namely Ksec and Msec), and part of the fun of reading the book was figuring out what those units meant intuitively when a character mentioned that something would take a couple Ksec to do.
(It helped a bit to remember Adm. Grace Hopper's rule of thumb that "pi seconds is a nanocentury".)
In space disconnected from any plantary cycle is probably the only setup where a metric/decimal time system makes sense because you can set the length of your 'day' to 10 kiloseconds and have it probably work out ok with humans if you change the lights to trick our circadian rhythm.
People here are conflating a decimal calendar or decimal time with metric time.
In its evolved form as SI, the metric system very much does have a unit of time. It is the second, and one can apply metric prefixes to it. So to those wondering what it would look like: It would look like, and does look like, kilosecond, megasecond, gigasecond, and so forth. I'm sure if you think about it you will recall having come across milliseconds, microseconds, or nanoseconds, somewhere in your lifetimes. (-:
Arguably if we are sticking with the existing definitions of days and years the reason we use a base-60 is because that is a degrees system. We are respecting (approximate) circular travel. It would almost make more sense to express time in radians in that case as that is the metric measure of angle. We are about 3/4 Tau through this year, and I'm writing this at about 1.2 Pi on this day.
That's exactly what I think would happen if we tried to use angular units for days or years (or even months): we'd either end up back where we started with a ~360-based system with lots of divisors or a percentage system. Exactly why I choose to use Tau in at least one example because radian systems using Tau are much are obviously "percent of the pie chart" than Pi examples.
We totally could [0], it feels less metric though when we're limited to messing with the time in the days and the grouping of days and still have to deal with the messy remainder of roughly 5.25 days assuming we have 'metric-y' 10 day 'weeks.'
[0] Minus societal inertia and that the current calendar works well enough for all it's aesthetic messiness.
> what's to stop us from dividing a day into 10 hours with 100 minutes each?
Same reason you can't just change the official language of your country overnight. It requires widespread consensus both in terms of users ability to use it and their systems' ability to understand it.
>> Any metric time system stumbles on the fact that 1) Days do not even divide into years by 10 and there's not even a whole number of days in a year and 2) calendars should sync with the seasons to provide any real use.
Only because a "year" is a measurement of how long it currently takes a specific planet to orbit its star. On larger scales such specifics don't matter. There is no daylight savings time in space.
"In computing, at least internally, metric time gained widespread use for ease of computation. Unix time gives date and time as the number of seconds since January 1, 1970, and Microsoft's FILETIME as multiples of 100ns since January 1, 1601.[7] VAX/VMS uses the number of 100ns since November 17, 1858 and RISC OS the number of centiseconds since January 1, 1900."
> Only because a "year" is a measurement of how long it currently takes a specific planet to orbit its star. On larger scales such specifics don't matter. There is no daylight savings time in space.
DST is kind of meaningless here. It's not an inherent feature of the calendar and it's a dumb hack that wasn't even great when it was implemented, I'm all for getting rid of it.
Sure yes when we become a multiplanet species maybe metric time will make sense for use at a human level calendar. What I was really talking about was a metric calendar system today and for use on Earth. Even off planet mapping day night to the diurnal cycle will make sense and assuming it's a planet with seasons and a breathable atmosphere the calendar will be more useful if it can match the local seasons. If that becomes an issue we'll probably have a calendar for each planet and then a universal date system used as a translation layer between different calendars and by people living in space where seasons don't screw things up.
As for the variability and year that's just as bad for a metric calendar as our current Gregorian. None of that really matters though because today the calendar needs to work for people living on Earth today. If we make it to mulit-planet/solar system we can figure out Stardates then.
> Metric time is a realworld thing
Only at the level where humans don't really interact with it directly. No one (well I'm sure someone out there does but to a reasonable approximations no one) uses epoch time directly in their daily interactions with people. It's communication layer for machines not for people.
I could see dividing the day decimally working pretty well.
Right now a typical work day is 1/3 of the day. This might be a good opportunity to drop it down to 3/10 of the day. Then you have the work day neatly dividing into thirds for a morning break and an afternoon lunch or vice versa.
Most human level scheduling currently works at a 15 minute resolution anyways so hundredths of a day would be the perfect unit for a lot of things I'd think. Instead of meeting someone at 3:45pm, you'd just meet at today.66 or something like that.
In favor of existing metric time proponents, a kilosecond is 16.7 minutes, which as you suggest is a pretty good unit of resolution for most scheduling concerns during a day of human activity.
The fun problems happen because most of the prefixes between kilosecond and megasecond (nearly a fortnight at 11.6 days) and between megasecond and gigasecond (a whopping 31.7 years) are either deprecated or non-standard to begin with. For instance myriaseconds (10^4 or nearly three hours) might be useful, but myria- was dropped from the metric prefix list for good reasons.
10 days to a working week is not long if your weekends are 5 days long :)
Anyway, astronomy does use "Julian Dates" which are timezone agnostic (which means era and location agnostic), rational number time markers 0-based on the "beginning of history".
The problems of seasonality and divisibility remain when you start caring about human life patterns more, as you suggest.
I think this is a great example of how specialised numbering / counting can have advantages, in specific domains. Most imperial vs metric arguments tend to degrade into "my <slightly contrived> use case works for my number system, but not yours!", or the more nuanced "the number of use cases where my system works well is higher than yours". While I do fall on the metric side of the argument even for most of these, I think a more reasonable way to approach it is that by standardising, we lose some domain specific tricks and perhaps take on a tiny bit more complexity, in order to have a more consistent and unified system, overall.
Agreed, but I think we should also pay attention to reasons which have nothing to do with practicalities... however they are represented.
In the medieval world of that novel, people didn't count much. Most people didn't use money much, and everyday language didn't place much demand on counting systems. The domains where numbering systems were used beyond simple basics were pretty isolated. Shepards count sheep. It's probably the only thing they ever count past 10, so a counting system for sheep is what evolved. They didn't interface with warlords counting troops, so there was no reason for these numbering systems to converge.
It seems obvious to us that counting systems should be universal, but standards don't tend to appear in advance. They appear when needed.
this is also the reason why it took until the industrial revolution for a wider used system to develop. Even before metric became standard, a lot of local measurements existed inside countries.
mass manufacturing required a system which would work outside the local sphere.
Good point. I think this story also interweaves practical and cultural elements.
The industrial revolution changed how measurement systems were used. It became important that a 13mm fitting measured in Paris was 13mm in Milan. Also, that age had novelty everywhere. Cobblers & weavers were separate worlds in medieval times. It didn't matter if they used different units of measurement. Novel industrialism required it.
On the cultural side, there was the French revolution. They wanted to throw out everything old and irrational. Old measurement units got the same guillotine treatment as old rulers. Tradition must die. This was the political and cultural environment that yielded the metric system. The political element also explains why the British Empire didn't adopt it.
The BE also needed rational units, ultimately. But, instead of adopting the radically rational metric system... they tweaked their medieval system into standard "imperial units." Why?
First, they weren't going to adopt their enemy's stupid system. Second, their philosophy was conservative. Tradition must live.
It's interesting how the ideals of the era (republican vs parliamentary monarchy) were mirrored in these decisions.
Oh but there was a metric time! Or at least a decimal one.
After the French revolution, some attempts were made to rationalize existing systems of time, the republican calendar [1] being probably the most famous, but hours and minutes were adjusted too [2]. Usage lasted slightly over a decade at the end of the 18th century.
With a decimal second at 0.84 a current second: 100 decimal minutes per hour and 10 decimal hours per day.
But, since alpha brainwaves (the most dominant) are almost exactly 10hz, regular seconds have a naturalness to them. Then again, maybe with decimal seconds, our brainwaves would adjust :)
OT but I must: I've always hated this use of "invented": they were the first to successfully cover a particular (small) distance using a self-powered device, which we today consider a first successful flight, out of many competing teams striving to do the same thing at roughly the same time.
I hate the use of the term because nobody has really "invented" anything in the last century or so. We are always building on the shoulders of giants enabling us to apply existing knowledge in new directions. Heck, Gallileo did not invent a telescope, but he did point a scope at the stars and planets.
We could arguably say things like Leibnitz "invented" integrals, but he actually gave them a nomenclature and written language, whereas many contemporaries worked on infinity calculus at the same time (including Newton).
I think I have a problem with the use of the term because it is so overloaded and can mean a number of things (I've heard people say things like "he invented gravity" which just boggles my mind, just like your use of "inventing a flight" where there were birds flying forever and people strived to fly for just as long).
I am guessing it is just me who is weird, but I wonder if it is so? :)
But to claim imperial measurements were key to implementing a very short powered heavier-than-air flight (lots of qualifiers, given myriad successful flights had occurred prior) is a stretch.
> I have never even heard of a metric angular unit.
Yet it exist: https://en.wikipedia.org/wiki/Gradian
I'll be the first to acknowledge that it doesn't seem add value over, say, using 1.0 for 360º or just plain ol' raidans (2π)
In physics it is not rare to see seconds used, with scientific notation, for measuring periods much longer than an hour. But for practical purposes it is very nice to have units which are easily divided into thirds and quarters, which is possible in base-60 but not base-10. This is equally true for angles, which also tolerate eighths (45 deg) and ninths (40) of a circle.
The impractical division of liters to 1000 milliliters has after all given us a couple of incompatible reifications of metric measuring cups and ugly numbers in recipes. 960 = 64 * 5 * 3 might have been nice if we were willing to tolerate a "metric quart" which differs from the liter (alternatively, a "baker's milliliter"), and recovers the teaspoon, tablespoon, ounce, cup, and pint in round numbers.
> almost no one advocates for metric time or angular units.
Frequency — hertz (SI) is turns per second, engines RPM is revolutions per minute. Integral would produce turn with fractions.
Turn, half turn, quarter turn, used in common language. Centiturn (0.01 turn) or milliturns (0.001 turn) could serve degree role. No need to force a change, degrees already replaced with pi in a middle school, though tau reflects turn better.
Time does not follow angle subdivisions (1/24/60/60 vs 1/60/60), second is SI measure, people can't even abolish DST, no change in foreseeable future.
That said we use spoons and cups on a kitchen, floors to describe building height, inches for plumbing and displays.
In precision rifle shooting, milliradian is very common.
Minute of angle is also still common.
Scopes are sold with both. It sort of depends on the discipline. For example service rifle scopes are almost universally in minutes of angle, while in the Precision Rifle Series the overwhelming majority use scopes in mils.
Super confusing is when a scope uses mils for the reticle but minutes of angle for the adjustment. That's just terrible, but they exist.
The calculator I had in high school offered three angle measurements: degrees, radians and gradians.
Gradians? It turns out that a gradian is defined to be 1/400th of a circle so right angles are 100 gradians instead of 90. They were defined during the French revolution (when else?) and are apparently still used in some European applications such as surveying. But given the importance of measurements such as 30° and 60° in mathematics (π/6, π/3 in radians) that end up being the rather ugly 33⅓ᵍ and 66⅔ᵍ in gradians, the measurement has not met broader acceptance.
Even more convenient is the metre, defined as the distance travelled in one such second by light in a vacuum divided by 299,792,458, and "only within a spatial extent sufficiently small that the effects of the non-uniformity of the gravitational field can be ignored."
As far as metric angular units go, there's the gradian (https://en.wikipedia.org/wiki/Gradian) of which there are 100 in a right angle. I'm not sure where they're in common use, but they're the reason that most scientific calculators let you switch units between degrees/radians/gradians.
It's not just different occupations that use different counting systems. Apparently in Japanese you count liquid using one set of names, grain another, and countable things with a third, people with yet another. Or something like that.
In English we do something similar. Small units of people are 'single', 'a couple', 'menage a trois' etc. Not to mention the myriad names for groups of things (herd, flock etc).
Well, the radian measurement of a plane angle can be defined as a ratio of the length of a circular arc divided by the length of the arc's radius, so the "metre per metre" (a.k.a. "1") is a legitimate (derived) metric angular unit.
Esperanto didn't catch on because a lot of people feel like it's not the right tool for the job - there are forks and whole different projects that try to mitigate the issues.
Forks mostly mitigate philosophical issues, like gender neutrality, continental neutrality and such. That's a job, but not (arguably) the job. S
The job was to be an easily learnable lingua franca, a common second language. Esperanto (also the forks) is a better tool for that job than english. All else equal, it's much quicker to learn.
Returning to the metric analogy, I think it's interesting to see the whys.
Ultimately, the quality of a language system is not the only or main thing leading to its adoption. There's a massive cultural element. The metric system was ideologically compatible with the French revolution and enlightenment/scientific/modern cultural ideals generally.
It was also useful individually, often by influential individuals (eg scientists). Even if everyone uses another system, it's still worth learning metric so you can do math, engineering or land surveyance more easily. You can always convert units for communication purposes.. I assume it's still like this in the states. If you need to calculate volume, you use metric and then convert to square feet or gallons.
This gave metric systems a bootstrap that esperanto didn't have. This has a parallel to network-effect products. You can't displace Twitter or facebook just by making a better alternative. That only matters once you have millions of users. You must have a bootstrap... a reason for individuals or small groups to use it regardless of overall usage.
I do think that that's a problem with esperanto, but large-scale things like that are only part of the problem. You could also, just as reasonably, frame it as a sort of, "Why don't more people learn esperanto?"
To that question, I found this YouTube polyglot explaining why he doesn't think esperanto is a language to learn raises some very good points: (https://youtu.be/n4AklOtfhMo - in french) The one I found compelling is that, in the absence of an economic motivator, you really need to fall in love with a language to remain motivated to learn it well. Where esperanto doesn't really have much of a cultural history or literary tradition, it just doesn't offer most people a lot to love.
This is one reason for the pasporta servo - essentially a free airbnb for esperantists who were travelling. As a young person I thought it was incredibly compelling that there was a language which would make me part of a subculture where anyone will host you while travelling.
Nowadays there's couchsurfing.com, which simply has a larger subculture, and as such the pasporta servo is not that useful any more. But it was a clever way to address that challenge!
I would say that esperanto does offer some inherent reasons to learn it. It's very easy to learn, relative to natural languages. That's what it was invented for. It's fun to make fast progress, and I think this is the biggest motivator for people to learn it.
It's also useful to learn a second language, because learning a language makes it easier to learn languages. There are some school programs teaching esperanto for this reason. It's part of their path to learning english.
Besides that, there's linguistic interest & idealistic interest.
You're right though, that it's all about the inherent reasons. There are no books to read or people to talk to. That's one hell of a downside.
I think klingon and dothraki are good reference points. People learn those for no practical reason.
But then, think about what's implied by those being the big reasons to learn the language. They implicitly relegate esperanto to the status of a toy language, comparable to the Lox programming language from Crafting Interpreters. You don't learn it because you actually want to speak esperanto (or program in Lox); you learn it as a simple model you can use to learn the techniques you'll use to accomplish some other goal, such as learning how to learn languages.
It's definitely different if you really like the ideal of a language that doesn't belong to any one group of people. But I'm guessing that, nowadays, that's a compelling motivating factor for fewer people than, "I really like Star Trek," is. Klingon's rich cultural history may be a constructed patchwork, but at least it exists.
That wasn't the goal. Esperanto didn't take. Esperanto was relegated. Those are the reasons remaining, and they are enough to support the language to some extent. It's not the reasons that relegated the language.
Note that these are merely the books where the copyright has already expired, so they can be freely put online. There is much more of the fresher content.
It's not far from that, in terms of the original purpose.
Esperanto is very easy to learn, compared to a natural language. English is the right one to compare with, since that became the international lingua franca esperanto wanted to be.
There are even some studies suggesting that the quickest way to teach english is to teach esperanto first, and the language learning skills acquired shorten the path to fluency enough to be worth it.
I think 10X is true in certain situations, but displacing incumbents can be more about path dependence than degrees of improvement.
I would say it's not always as cut and dry for the benefits of Metric over Standard.
When doing math? Yes please, sign me up.
For measurements around the room? Inches is a pretty good unit. CM is too small, DM is too big. There is a reason 90% of tabletop wargames (even those made in the UK by Games Workshop) still use inches for movement. It doesn't matter in a wargame how many inches are in a foot, or how many feet in a mile. You stay 100% in inches, and it just works.
Another interesting place is in carpentry. You can divide 12 by 2, 3, 4, 6... it just works well. There is a reason the bootstrap CSS framework uses 12 divisions and not 10. Again, the number of feet in a mile don't matter when framing a house. Are the studs 18" on center, or 24"?
I'm pretty sure that dividing 12 by 2, 3, 4, 6... works in metric countries, too. :-)
But seriously, take something like the spacing of things like studs, which is commonly 16" or 24" in the US.
24" would indeed be a pain to divide by 2, 3, 4, or 6 if we were instead working with the same spacing but in metric, where it would be 60.96 cm [1].
But in Norway, the first metric country I happened to find information for, they don't use 60.96 cm stud spacing. The use 60 cm spacing for studs, joists, and rafters (23.622"). Dividing by 2, 3, 4, or 6 for them is as easy as dividing by 2, 3, 4, or 6 in a place using 24" spacing--and they also get easy divide by 5.
If you've got some random physical thing to measure that was not build by humans, like say how tall a tree is, you are probably going to get some length that isn't exactly 2, 3, 4, or 6 times an integral multiple of the smallest division on your ruler, regardless of what system your ruler uses.
For things that are built for humans and for which we will commonly want to divide them by 2, 3, 4, or 6 (or other small integers that we might anticipate), we will tend to pick their sizes to facilitate that using the units we expect the users to be using.
[1] That one does actually come out as an integral number of mm when divided by 2, 3, 4, or 6 so it is not too much of pain. It's just having to deal with more digits and a decimal point as opposed to also having to deal with something that falls between the marks on your ruler.
> For measurements around the room? Inches is a pretty good unit. CM is too small, DM is too big
Can you perhaps elucidate further on which 'Measurements around the room' require multiples of 2.5cm units to describe, and that fail with 1cm units.
> There is a reason 90% of tabletop wargames ...
So:
a) tabletop wargames are not the way we evaluate the convenience of our measurement systems, and
b) you just said 90%.
90%
90 / 100
How wonderful is it to use a ratio that world+dog totally, immediately, nay intuitively understands -- a ratio of a given number to the fixed value of 100.
For people genuinely committed to factors of 8, 12, 16, 60 etc -- how can they be comfortable with percentages? It's a betrayal!
Surely fractions of, I don't know, let's say, a gross (144) would be more natural.
144 = 12 x 12 -- so you instantly have all the benefits of 12, multiplied by another 12. What's not to love?
Rather than saying 90%, you could more naturally say 130/144 (okay, that's only approximately 90% -- it's actually 90.27777...%) but as you say, base 10 numbers are difficult to properly convey your true intent, so you can come up with a better number there.
For carpentry, 12-inches-to-a-foot isn't actually that useful, since wood is never the nominal size. For lumber, nominal sizes are measured assuming that sawing and planing remove no wood, but sawing and planing will remove about 1/4 to 1/2 an inch in each direction. That means that you can't stack two 2x4 to get an exact 4x4, and you can't use dimensional lumber to fill a nominal 1 foot gap without cutting.
Carpentry, both the house-building and furniture making kinds, have adapted by emphasizing tricks to measure lumber without rulers. That means starting with more wood than needed, and cutting down to make pieces fit.
Where do you use division in carpentry? My understanding is that it primarily deals with adding up or subtracting to some length, since you must nearly always account for thickness. In that sense, it doesn't really matter if you use inches or centimeters, since you never convert units and never do any calculation that is more complicated than plus or minus.
AFAIK, IKEA uses millimeters, for example.
Bootstrap CSS doesn't seem all that relevant to the metric vs standard debate either, since it's neither of them. Time and angles are also divisible by twelve, for example.
You use division when coming up with even intervals. For example, "nail this panel to that board at 3 evenly-spaced locations." This shows up in joinery, too.
That said, I do a lot of carpentry and woodworking, and have switched entirely to metric. I find it a lot easier to do addition and subtraction, as you say, but mostly it's more calculator-friendly. Adding ((273mm / 2) + 60.5mm + 546mm) is a lot easier to punch into a calculator than ((10 and 3/4 inches) / 2) + (2 and 7/8 inches) + (1 foot and 9 and 1/2 inches).
Nice! I think you'll like it. One thing, hope you noticed that it's an RPN calculator... takes a short amount of time to get adjusted to but is superior to algebraic entry.
Here is an expanded manual on working with fractions:
If you want to play with the HP family of calculators that are RPN check out Free42 (Android, Mac, and Windows emulator for a classic HP calculator. Note, it doesn't do fractions like the 35s)
Non-metric systems used industries were chosen through experience and optimized in the same way that genetic algorithms optimize.
The SI units are rarely, if ever, more convenient than whatever legacy standard they replaced, but the path dependent development of naturally defined measurement systems meant different results in every country. Shipbuilding, lumber, textiles, printing presses would also end up with varying degrees of compatibility or difficulty in working with materials sized in another domain.
As an aside, the same people extolling the value of the metric system's base ten nature have little problem explaining why the dimensions of A4 paper are not round numbers. The legacy systems in their countries didn't come from users being unaware of a base number system, they just used to prioritize other conveniences that a measurement system can provide, such as how A0 through A8 paper sizes can be simultaneously cut from one sheet of paper.
Your post seems well considered, but I apologise that I'm struggling to ascertain the point you're trying to make.
I can comment on this bit though:
> As an aside, the same people extolling the value of the metric system's base ten nature have little problem explaining why the dimensions of A4 paper are not round numbers.
Metric isn't about round numbers -- this seems to be a common misunderstanding.
Metric users are happy to dive into sub-unit numbers (6.35mm is a number we see an awful lot).
Metric, I think, is mostly about being aligned with most of the world. A common language, as it were.
Secondly, it's about some pleasant relationships between different units (length, mass, velocity, volume, energy, etc.
Probably equal second, it's about making calculations easier.
Round numbers are irrelevant for this, of course. But base-10 is a massive boon.
I think the metric system facilitates trade, especially in bulk quantities of raw commodities, between different industries and jurisdictions. And, I think the decisions made to arrive at a universal standard are a combination of top down and "perfect" that typify nineteenth century science.
Earth doesn't have a 40,000km circumference, but it doesn't matter because anyone who needs a precise measurement will use some sort of aid. Similarly the mass of water in 1 mm of rain over a hectare isn't actually 10,000kg, but you'll use some aid if you need a more precise number taking temperature and actual contents of rainwater into account. Of course using nautical miles or acre-feet with high precision required aids of some kind, too.
However, legacy systems of measurements were developed to minimize the number of instances where people like machinists on a factory floor need an aid such as pen and paper to do a calculation. Big problems like Fermi estimates are much easier with the metric system, but day to day problems within a specialized profession probably are not.
I do think the benefits of a more universal system vastly outweigh the costs to convenience for everyday users of measurements, but I am skeptical of many of the rationales used for advocacy. Perhaps if an international system of measurements was designed today it would be even better designed for binary computers as computational aids rather than decimals and paper, though that would be an even more difficult transition.
Interesting to note that decimal fractions (e.g. 0.3) are awkward to represent with floats in computers, whereas fractions based on 1/2, 1/4, 1/8, etc. that are often used in the non-metric system are a very natural fit for the float representation.
That would be a good point if the non-metric system we are discussing was based in binary. It's mostly (but not entirely) based around base-12 and uses 1/3 very commonly as a fraction (as well as 1/6). 1/3 and 1/6 does not have an exact floating point representation.
But literally no one uses stones. People in UK when measuring weight of humans? I have never seen it in any other case. You don't buy things in the US by Stone.
billti didn't say anything about who uses things, but you can enjoy how similarly unnatural binary floating point is for converting 8 inches into feet if you like, or 2 fluid ounces into U.K. pints.
If you use decimal with metric, the units and prefixes play along with you very well (huge advantage). If you use other fractions with metric, you get no special bonus or burden (neutral).
If you use decimal with US customary ("imperial"), you get no special bonus or burden (netural). If you use other fractions with US customary, you get no special bonus or burden (neutral).
In summary, there is absolutely no rational reason to stick with US customary, besides legacy compatibility (technical debt).
Someone here sometime back tried to say that dividing by 2 or doubling a value is easier than X10 or /10 (pro imperial argument). To me, metrics is so much easier. It's literally as easy as moving the decimal point 1 place left or right. No math is involved at all. Just moving a dot. How that is supposed to be harder than doubling/halving eludes me.
The disconnect here is in physical processes. If you have a physical beam that you need to divide in half, that is much easier than dividing that beam into 10 pieces.
Where this is really important is when you are making standard rulers. Your standard measure is approximately the size of a yard or meter; making a ruler that measures inches or centimeters requires dividing that length by 100 or 36.
The metric system isn't really possible until we developed machines that can precisely and accurately divide lengths by arbitrary divisors, which happens only in the late 18th century.
I've seen this example of egg dozens everywhere but i don't get it, egg dozens aren't related to inches. It's just a random number of eggs that happens to be common in packing. Let's say there's any practical reason to have a measurement system bases on 12 egg packs, it falls flat with a 100 nails one...
Eggs is a bad example. Try building a wall and dividing it into 3 sections. The symmetry looks good, but metric makes it a real pain to do that, while base 12 systems make it easier.
Plywood is sold in 8 foot long sheets, or 240cm in metric countries. 200cm would be a more natural metric size, but it is too short to be useful (because plywood is used for things that need to be human height), and so being compatible with the US standard is the compromise construction uses.
Metric is nice in math when you can choose to your values to make things easy. As you get to engineering things get messy just because the nice sizes are not normally even values. Of course all systems suffer from this, 5000 feet in a mile would be a nicer measure but it doesn't fit in with the other things that you want in a system so you compromise. Metric compromised differently and is equally annoying to use for everything.
We should still go metric in the US, consistency is useful.
I'm even further from getting it now. 240cm being a multiple of 12, it can be divided by 2,3,4,6 without precision loss.
Also this logic around inches only works if you happen to need to divide 1 inch. It doesn't work anymore if you need to divide 1.1 inch.
It actually work exactly the same in the metric system if you need to divide 1.2cm
Engineering is math. You start from your constraints, and finish with an acceptable level of imprecision based on your requirements, your tools and your materials. Whatever you do it's never precision work, exactitude only exists on paper.
Plywood in the US is sold in feet. Europeans cut plywood into metric based sheets. Ever try to buy Baltic Birch for wood working? It's actually a different shape than a US sheet of plywood.
Sorry but i fail to see how it's handy.
To stay with thr egg pack unit, it's much easier to say i want 7 eggs rather than a 0.58 of pack (not even sure it's right in egg/inches).
Even this i find it much more convenient in 10s.
A pack of 10 eggs?
You can easily express any content (0.1, 0.2, 0.3...)
Move to the lower unit (move the coma). A quarter of an egg in egg packs? 0.025
Want to move in the egg unit? 0.25
Please prove me wrong but i fail to see how it's easier in 12th, when using a decimal number system.
You're coming at the problem from a metric point of view.
Your instinct is to immediately convert into decimal point numbers, but the strength of the base 12 system is in fractions.
Its very easy to visualize and measure one half, one third, one quarter of something. Humans in their daily life don't come across a situation where they need 0.2 of something. It is much more natural to think of halves and thirds.
Milk (as an example of imperial liquid measure) is another good example. Nobody looks at a gallon of milk and says "boy I wish I could only buy 0.7 of that". The brain is just wired to think of halving and doubling, so we have quarts which are 1/4 gallons, and pints which are 1/2 quarts.
For another example, You never hear about people "0.7x" a recipe. People halve or double a recipe, and imperial measures make that easy to do.
I like the phrase: Imperial units are for humans, SI units are for scientists. This is why I prefer the Fahrenheit temperature scale. The Celsius scale is much more "concrete" in that it has a physical basis for degree 0 and 100, but that doesn't matter for humans. I never have to relate temperature in terms of boiling and freezing water.
In Fahrenheit, 0 is "really cold" and 100 is "really hot". It's arbitrary, but more human friendly.
We really think differently then :D
I definitely don't think about fractions but adapt the unit to my needs. I use fractions to get to
what i need, but the same way i would add, multiply and substract.
I don't relate at all to the Farenheit scale. You can give whatever number, it just doesn't talk to me at all. The Celsius one does though. This is not a matter of a unit being better than another, but what we're used to.
There is another human advantage to Fahrenheit: the degrees are more precise. One degree Fahrenheit is a noticeable but small difference. One degree Celsius is 1.8 degrees Fahrenheit, a much bigger difference. You're practically forced to use half degrees, which works but is ugly.
If the SI people could have broken with the idea that everything must be a strict power of 10, they could have used 200 degrees instead of 100 and had much more human-friendly units.
It's not terribly self-consistent to talk about base 12 (which is not what the old systems in fact used) being strong and then talking about the intuitiveness of 100 Fahrenheit in almost the same breath. (-:
Why not? The use case is different: I have never in my life needed to do quick mental math regarding temperatures. Base 12 is great for quick mental math.
Both the fact that imperial uses base 12 for some units and the fact that Fahrenheit is centered around the human experience of temperature support my larger point that imperial units are more ergonomic.
> Please prove me wrong but i fail to see how it's easier in 12th, when using a decimal number system.
It's not. You have to have a base 12 "decimal" system (dozenal or duodecimal). A half is 0.6, third is 0.4, quarter is 0.3, a sixth is 0.2, an eighth is 0.15, and a twelveth is 0.1.
Eight eggs is 0.8 of a dozen, 0.08 of a gross, or 8 "pg", per-gross, akin to per-centum.
The advantage is that all of those divisions are clearly marked on the ruler, so it’s easy to align your line/cut with it.
In contrast, cutting a 10cm thing in thirds or quarters requires estimating the point 0.33 or 0.25 of the way between marks, which is perceptually harder.
And cutting 3.93701 inches in thirds is somehow easier? Even with 4in, you end up with 1.33 inches. Not very different from 3.33cm is it?
You're just taking arbitrary numbers that are easier to operate with using the imperial system. The metric system is superior because most numbers are easier to operate and measures in fractions of ten.
But that's exactly the point--historically, you wouldn't cut 3.93701 inches. You don't have the precision to do it nor do you have any real reason not to stick with "round" numbers or close enough. Rough carpentry (e.g., framing a house) is often only accurate to a 1/2" or so; very fine furniture might go down to a 1/32rd.
Note that machinists, who do want that sort of precision and can achieve it, mostly work in metric or metric-lite ('mils'=1/1000s of an inch).
I never had issues with cm/mm honestly. And half a milimeter is always a precision hard to reach with home hand tools, so the need to have 0.33 milimeters on a ruler is not there. Tools that reach that precision are in micrometers.
... and only has two prime factors, the same as 10 does, undermining your original point about prime factors.
In 2015, Cadbury stopped selling its creme eggs in packs of six in the U.K. and now sells them in packs of five. Ironically, a subsidiary of a U.S. conglomerate (Cadbury having been taken over in 2010) metricated creme egg packaging.
I'm a metric system person too, leaving with an us imperial system person. I think that the mental model is different. Metric is made to switch units easily, you need precision, just move the comma to get it. The imperial system is used by sticking to the unit and use fractions of it.
I believe that jedd was characterizing both non-metric systems, Elizabethan and before, as broken.
That's true, but not for the reason that people usually think.
The common misunderstanding of the history here is that the world went straight from measuring things with bodyparts to metric. It did not. Even if we count Charlemagne as having done that (which he didn't; he having received physical standards from Harun al-Rashid), there were nine centuries of mucking about between that and the invention of the metric system, during which time physical standards were used, lost, stolen, forged, damaged, cunningly altered, eroded, deformed, and replaced. Furthermore, people did various gymnastics to account for the results, such as changing the number of onces to the livre or to the marc.
England was one part of a wider world, and that world was a Hell of a mess.
Metric was not just decimalization, it was consolidation on a single standard, which was particularly pressing in 18th century France, by which time the Carolingian system had shattered into hundreds of thousands of different systems in France alone. (Lookup tables of the time also included conversion factors for towns in France's neighbours. The mess wasn't limited to France by any means.)
Modern stuff like the last few official users of the pint in the world not agreeing on how big it is, is in fact peanuts compared to the mess that the metric system replaced.
It's also worth noting the French-English angle here.
The meter was basically the Parisian yard; the crazy definition of 1/10,000th the length of a quarter-circle running from the north pole to the equator through France was picked because (a) it gave something very close to the Parisian yard and (b) it gave an agreed upon standard for all of the hundreds of disjoint local variants of the yard, as you mention.
So now that everyone has already adopted the meter, it's the standard, but if you're back in 18th-19th century England, which already had a well-standardized national system of measure, and here comes your long-time rival France with a new standard system of measure, derived from first principles, they say, perfectly rational, and it just coincidentally is the same as their old unit of measure, you're going to be a bit skeptical that you should abandon your units in favor of theirs.
I was, though, addressing the idea that the old system was broken, not the politics of adoption of the new system.
I haven't done the necessary research, but I expect that it wasn't as simple as only some Chauvinistic national rivalry. In the case of the United States, for example, the course of metrication was significantly altered by the weather.
I typically prefer imperial measures in simple projects because they tend do feel more practical.
In things like woodwork, carpentry, papercraft, etc and inch, a foot, or a quarter inch tend to "fit" very well and are easily divided.
Specifically with papercraft, I prefer working in inches over centimeters because inch, half inch, and quarter inch all essentially function as "full" units and are very easily divided/combined and tend to "fit" better with most projects. A half.inch tends to usually feel like a good margin. A few inches tends to work well for a card. A quarter inch generally seems right for a small spacing. That is significantly more useful to me than base-10 conversions because (for example) 1 inch and 1 half inch feels easier to keep in mind than 1 centimeter and 5 millimeters (or 1 centimeter and 1.5 centimeters).
Traditional unit in metric crafts is cm and the smallest traditional distance is 0.5 cm (pronounced "half" not "O point 5"). Notebook grid is 0.5 cm for example and you write and draw everything at shool on that grid so you get used to it (and get intuitive feel for how long a cm (2 grids) is in the process).
The dimensions you're mostly using are 0.5 cm, 1 cm, 1.5 cm, 2 cm, 2.5 cm, 5 cm, 10 cm.
> A quarter inch generally seems right for a small spacing.
A quarter inch is 6.35 mm compared to 5 mm (0.5 cm) which is basically the same for estetic purposes, any preference will be caused by familiarity more than any objective criteria.
> 1 inch and 1 half inch feels easier to keep in mind than 1 centimeter and 5 millimeters
Nobody says or thinks "1 centimeter and 5 millimeters" just like nobody says "I'm 1 meter and 80 centimeters tall". You're "180 centimeters tall" or (less often) "1.8 m tall".
There's even a word in my language "półtora" which means "one and a half", so 1.5 cm is just "półtora centymetra". But even with languages without this word people think "one and a half cm" not "one cm and five mm". You almost never mix units in metric in the same expression, it just makes everything difficult for no reason.
I think Americans don't understand that decimals are second nature to people using metric. When you write 1/2 we write 0.5 but we think the same - "half".
>Nobody says or thinks "1 centimeter and 5 millimeters" just like nobody says "I'm 1 meter and 80 centimeters tall". You're "180 centimeters tall" or (less often) "1.8 m tall".
one-eighty is quite common. That might depend on the country and language.
If we're talking about what's common in English, I think it's a little odd to discuss European metric habits in the context of the English language.
While English is a "lingua franca" in Western countries, the two main native-English-speaking countries in Europe are very recent metric adoptees.
Ireland didn't finish adopting the metric system until 2005, so still use imperial units for many colloquial uses; e.g. human height & weight.
The U.K. is further behind, and if you couple that with the nationalistic associations the imperial system will have there, colloquial uses are even more widespread.
I think metric use in English is only going to become more natural and fluent with generational use.
Malta should be included too; They used to be part of the UK till 1964, they still drive on the left side, so no idea how they feel/speak about metric.
I guess. "One" is shorter than "hundred" in English while it's the other way in Polish (jeden vs sto).
I was very surprised that English people say "fifteen hundred" for 1500, I never thought about that number this way before, it was always "tysiąc pięćset" (one thousand five hundred).
Most English speakers say the year is "fifteen hundred", but it's mostly American people who say "fifteen hundred" in other cases.
en-GB: Today is the thirty-first of August, twenty twenty. The USA has reported an additional one thousand, seven hundred and seventy one Covid-nineteen cases. I would normally leave work around five-thirty, since I can catch the seventeen forty-five train home and watch the end of the six o'clock news. If I miss the train, I might take the two thirty bus instead [i.e. bus 230], or else the one three five.
Are you sure? Intuitively I would have said, that "I'm one eighty tall" is an abbreviation for "I'm one [meter] [and] 80 [centimeter] tall".
Thinking about it, if I measure something with a folding ruler, I would more naturally say "it's one meter eighty long" (German native speaker here, as already said elsewhere, with other languages YMMV).
But the point still stands. In metric, you can slap the numbers together or separate them, convert them to different units or sprinkle easily units in between or not. It all works. At worst it is just moving the decimal point around or adding/removing zeros. Very easily done in your head.
Well I suppose the nice thing about metric is that it doesn't matter!
You may be convincing me though, since in feet and inches it does matter, and it would mean as you say - 'looks about 10 11' means 10'11", not 1011".
In the UK though we generally don't mix metres and centimetres - '1 8' would mean '1.8' not '1.08', though I'd say the decimal point would rarely be elided, so that's clear.
So I just wouldn't say 1 80 about metres unless the question was 'how many metres' - and then I'd mean 180m.
But yes, that's exactly how you would say it in German. There might be some part of the brain reserved to parse that sentence as "I'm (one) (four and 80)" but this doesn't feel weird or confusing at all.
Telephone numbers on the other hand are more confusing. Luckily you don't need to say them out loud anymore these days.
In French, you'd say "je fais 1 mètre 80" (literally "I'm 1 meter 80") and write it 1m80. Saying "180 centimètres" would be weird in a casual conversation, but fine in a professionnal setting. For a weight of 1500g, you'd usually say "1 kilo 5", maybe "1 kilo 500", but rarely "1 kilo 500 grammes".
So yeah, decimals are so used that you don't even need to tell the unit, it's implicit. I once had an american argue with me about Fahrenheit vs Celsius, because "Fahrenheit is more precise". I guess he was either a superhuman who can feel the difference between 20°C and 21°C, or someone who never heard about decimals.
In Polish it's common to use "deko" (ang. deca) especially for weight of groceries. So it's perfectly normal to buy "20 deko sera" instead of "200 gram sera" (both means 200g of cheese)
I find the European 0.5 mm block is very small and cramped - I'm pretty in sure in Australia it's 0.8 mm by standard. Probably my small letters are almost 0.5 mm tall so I don't really know how to fit into 0.5 mm.
Whether this destroys your argument or not, I don't know. I don't think preferred measures really depend on this sort of thing.
(The size of the block is 5 mm or 0.5 cm, not 0.5 mm; I'm sure you know that and it was just a typing error)
You're not supposed to cram your letters into that 5 mm space: you generally use two lines, which gives you a 1 cm lineheight.
That being said, I don't like that raster size for writing. They're nice for drawing schematics and stuff, but for writing I very much prefer a grid of 4mm × 8mm (like this: https://www.dbs.be/images/vergroot/2518_2.jpg).
Are you using cursive? Cause I've seen some English people use capitalics in handwriting and then it would be hard for sure.
I find 0.5cm grid perfectly fine for writing, prefer it to the 0.9cm line notebooks (we have them too - for "soft" subjects like language learning where you don't need to graph anything).
> I typically prefer imperial measures in simple projects because they tend do feel more practical.
I posit that you almost definitely prefer imperial measurements because that's what you grew up with, and consequently have the most familiarity, experience, and comfort with.
And that's okay.
But it doesn't speak to objective practicality.
Papercraft - somewhat aside, have you looked at how ISO A series paper sizes [0] are determined? Now that's an exercise in gorgeous and thoughtful standards design.
I'll point out that I do a fair bit of woodwork too, and my equipment - rules, squares, drop and band saws, router table markings, screws, bolts, drill bits, etc - are all metric. I have a tiny number of imperial items (eg a dovetail jig from a company in North America) but they tend to not have to interact with any metric gear, and finding metric versions of these tools is difficult/expensive.
All of us metric-only people (let's say ~95% of the world) are just fine using what they grew up with to make & build stuff -- so it's going to be hard to demonstrate that imperial is 'more practical'.
I feel I should share this -- it's an explanation provided in the Leigh dovetail jig manual for why two things share the same scale. Leigh's based in Canada, which appears to be nominally metric, but I gather most of their market is the other part of North America (which obviously isn't).
I bought the metric version of this jig - and I'm ecstatic they make this. The metric measurements are just different scales & translations - they didn't redesign the device at all.
Decimals don't slow me down, but comparing fractions with different denominators does.
Most of the manual they mention metric values in parenthesis, but in some sections it seems the authors just, understandably, gave up.
I'm perversely envious of people who can effortlessly make sense of this:
"""
Section 8-23 : Why are the 1⁄2" and 11⁄16" [12,7 & 17,5mm] pin widths on the same scale line?
1⁄2" through dovetails are routed using a 7⁄16" guidebush.
11⁄16" through dovetails are routed with a 5⁄8" guidebush.
That's a 3⁄16" difference in size between the two bits ... and between the two guidebushes.
The 5⁄8" diameter guidebush for 11⁄16" joints requires that the guide fingers be opened up by 3⁄16".
This automatically makes the pins 3⁄16" wider but on the same scale setting.
This is clip of the reality show American Chopper, where a bunch of native imperial unit users, professional mechanics are trying to calculate fractions: https://www.youtube.com/watch?v=EUpwa0je6_Y
This conversation would never happen in a metric shop if the people there are above 2nd grade in their arithmetic skills.
That was hilarious, though the problem was the older guy kept changing his measurements, not the actual calculation. (I don't even use Imperial and was able to calculate the difference in my head as he said them (the young guy was correct each time)).
I agree that (at least part of) my preference comes from familiarity but I am not convinced that it is caused 100% by familiarity.
I happened to see this brief interaction in a video [0] the other day that pretty accurately illustrates my point of view. In summary: 2 makers (one german, one american) working on a device are looking at parts in hand to design as they build and one says "...if you put this 15 millimeters in from the edge. about half an inch". They first physically see/feel the distance they believe to be correct is 1.5 or 15 metric units (cm or mm) or 1 imperial unit (half inch). This is the case I find comes up frequently for me. Measures where moving a cut to line up to whole cm is too far and I end up working with half and quarter centimeters or awkward counts of millimeters.
Though, it is definitely possible that 15mm only felt right in that case due to familiarity with imperial measures and that 1cm or 2cm would have been fine.
I guess the "trick" is that even though 1/16, 1/8, 1/4, and 1/2 inch are all technically divisions of an inch, they all function in practice as distinct whole units that are (typically) easily converted. So when you are doing work in that scale range you have many options to match what you are working with.
Paper sizes are also another good example of what I am talking about. An imperial "letter" size page is 8 and 1/2 by 11 inches. To cut one in half in either direction, the calculation is easy: horizontal 8 divided by 2 is 4 plus 1/2 divided by 2 is 1/4 or vertical 11 divided by 2 is 5 and 1/2.
The similar ISO size (A4) is 210mm x 297mm would be cut at 10.5cm or 14.85cm. Sure you could just pull two A6 out of the drawer instead of cutting one A4 but then you are using ISO216 as your units of measure instead of cm/mm. In terms of practicality, cutting material stock in half is a pretty basic operation.
Can I ask why you consider consider 0.5 inches to be 'one unit' - but think 1.5 cm is not?
For me, a unit is akin to atomicity.
But units don't dictate what size something is or should be - that's what multiples are for.
> Measures where moving a cut to line up to whole cm is too far and I end up working with half and quarter centimeters or awkward counts of millimeters.
It's a poor tape measure that does not show mm.
Similarly it would be a poor tape measure that does not show 1/32 of an inch.
The fact that your measuring device shows these gradations doesn't mean your design needs to be aligned to any arbitrary subset of multiples / divisors though, surely?
> I guess the "trick" is that even though 1/16, 1/8, 1/4, and 1/2 inch are all technically divisions of an inch, they all function in practice as distinct whole units that are (typically) easily converted. So when you are doing work in that scale range you have many options to match what you are working with.
1/16th of an inch isn't just technically a division of an inch. : )
When you're working down to something tiny, both measurement systems will be able to represent absolute distances just fine - do we agree on that?
It's a matter of whether manipulating those numbers is easy or difficult (for me, working with wood almost always means working with integers - mm - so all calculations are delightfully easy). Refer my other post about the Leigh dovetail jig description of router bit and bush sizes - there's 4 different dividends in use in just that one short paragraph, so you have to convert them all to common denominators before doing any mental arithmetic with them.
> When you're working down to something tiny, both measurement systems will be able to represent absolute distances just fine - do we agree on that?
Yes. I guess it was implied by omission but I don't think either system is bad. My original statement was: "I wouldn't call imperial measures 'broken'"
> Can I ask why you consider consider 0.5 inches to be 'one unit' - but think 1.5 cm is not?
>1/16th of an inch isn't just technically a division of an inch. : )
Because I don't think of 1.5 inches as 1 inch + 0.5 inches, I tend to think of 1.5 inches instead as three 1/2-inches. What I mean by stating that while 1/16 is (and 1/2, 1/4, 1/8 are) "technically" divisions of the inch, they are _practically_ (or effectively) separate whole units that you step up or down to the same way you convert up or down between mm and cm.
I find sub-dividing material (or design) by a power of two to be very common. Working with metric units, this tends to always lead to handling multiples of 5 which I tend to find more difficult than handling multiples of 2.
Working with imperial inches and subdivisions of an inch in this way (for "normal" sized projects of the type mentioned in previous comments) means there are more options to match "whole" units to the specific measurement and you generally make new measurements in your work by changing units and adding/subtracting integer values of that unit. It is literally practical because it was derived from existing practices and matches them inherently.
As someone who grew up with metric measurements, I could easily use the exact same "practicality" arguments against the imperial system.
To me, an inch is a weird measurement that is slightly longer than 2cm, a mile is a bit farther than 1.5km, a gallon is about 4 litres, and I always have to lookup up what ounces are (let alone fluid ounces -- which I have to constantly remind myself are not the same thing). But that isn't because the imperial system is "less practical" in any meaningful sense -- it's just that I didn't grow up with it and so I have to constantly convert back to the system I know (and since the conversions will never be nice integer ratios, of course your "native" measuring system will appear to work better).
As for the whole "imperial fractions are easier to deal with" thing, I personally disagree but I suspect that's also because I'm not used to the idea. In everyday life I'm so used to seeing decimal quantities that from a young age I learned how to quickly deal with them. However, I must admit I struggle to handle fractions as quickly because it isn't as common as decimal division in my everyday life. I imagine the inverse is probably true for people who have dealt with fractional quantities their entire lives. I hasten to point out that most people wouldn't say nor think of 1.5cm as "1 centimetre and 5 millimetres", just as you wouldn't say nor think of 1⅝ inches as "1 inch and 5 eighths-of-an-inch".
Honestly this whole argument has always felt pointless to me -- is it not obvious that you will always find things you are most familiar to be the best tools for the job? It's almost like watching an Englishman and a Frenchman hotly debating which language is uniquely better suited to writing poetry -- all the while ignoring that equally brilliant poetry has been written in both languages.
> It's almost like watching an Englishman and a Frenchman hotly debating which language is uniquely better suited to writing poetry -- all the while ignoring that equally brilliant poetry has been written in both languages.
I think the French won that argument when they managed to kill off English alliterative verse.
Also feet, my goodness, is it annoying to read anything with distances given in feet. 600 feet! Wow, that's a long— wait, no, it's about 200 metres, not 600 metres, so not that long a distance. A thousand feet! No, that's not even close to a kilometre, that's just slightly more than 300 metres. And so on.
Really wish book translators would translate the units inside as well. In fiction the exact numbers don't matter much, so that'd be perfectly fine.
To me it sounds mostly that you like it because you're used to it. For me doing DIY projects in mm feels very natural (basically every measure is an integer), much more so than seeing videos of Americans juggling fractions.
I recently started watching some metalworking videos, and Americans in those use 'thou' (more confusingly aka 'mil') - thousandths of an inch. That seems mostly fine to me, it's a different scale, but whatever, it's just as sane if you don't need it to interact with volumetric measurements etc.
Woodworkers obviously don't need or want the accuracy of the 'thou' digit, but it seems to me that similarly normalising on decimal fractions and using 'huns' or 'around 12x thou' would be an improvement.
But then, they're used to it and happy with it, it's only viewers like me who aren't that are thinking about it!
(I'm British, so use Imperial in some contexts, including casually sizing small things in inches, but probably never fractional other than 1/2".)
It turns out that the thou is a great division for metal working. The even metric are just a little too course, or a little too fine for most metal work. Either way though machinists do great work in either system, to the same fine standards.
Oh I don't doubt it, I'm not saying it's some weird or wonderful exclusively American thing, I'm just too young to be aware of it from anywhere else, and suggesting that it or similar (tenths, hundredths) would be an improvement on 2^x denominated fractions even in applications that don't need such accuracy.
Put another way, I think if everyone (not just precision applications) used decimalised inches, it would just be a different scale and ~nobody would care to say 'omg why don't you use metric'.
The primary advantage of metric is that everyone else uses it. The decimal is useful, but fractions have their place as well, so there isn't a clear win.
Not really, you can learn. I spent quite a bit of effort in my twenties to convert myself over to metric for heights, weighing food, measuring liquids and such (I'm from UK).
UK had been officially metric my whole life and EU were at the time mandating pricing in metric.
Supermarkets were very reticent to use metric - or at least flouted the regulation, presumably as prices seem lower in pounds (UK 'lb') than kilograms. Now I find they often don't show weights but hide behind pack sizes for fruit pricing; presumably to prevent customers comparing. They do still have scales but it's a PITA weighing half your produce.
Getting comfortable so I could 'feel' what a particular mass (and £/kg) of apples was, say, took effort for me. Same with heights, and shifting to using kg for person-masses too.
I have relatives in the UK, and lived in London for several years -- the rage that the popular media was able to incite about metric (mostly through outright lies) in the older generation there is astonishing. Even more so they've managed to maintain that for some decades. I guess this is how they ended up leaving the EU.
In Australia supermarkets are obliged to have a pricing per 100gm for every packaged item on the shelves.
It's slightly smaller print, of course, but it's clearly legible and allows for a wonderfully simple price comparison.
EDIT: Btw, this story came out a while ago, and includes a fascinating montage clip from 1978 - a vox pop of UK citizens, obviously the most whacky people are chosen - but it's a magnificent blend of dumb (you'll use more petrol because you don't get as many kilometres to the gallon) and sad (I don't want to be part of a community).
The UK has the same rule for "per 100g" etc (depending on the object, the unit changes -- herbs are shown per 10g, potatoes per 1kg).
There are some exceptions, supposed to help market traders sell 6 apples etc. The supermarkets are using those, which I think was unexpected when these exceptions were allowed.
as far as i know, the 100g weight rule is standard across the EU. I have seen it on virtually any packaging i could find, with the exception of packaged fruits etc. (which obviously come per piece).
> Now I find they often don't show weights but hide behind pack sizes
Not legal, btw, unless you mean e.g. 'Lemons £1 (12p/ea.)?
The usual complaint is that the denominators haven't been standardised, so you might get A selling lemons /ea. and B selling them /100g.
But then, when they are literally sold as a number (or a rough number) in a net, as opposed to being weighed and stickered, even if there were a /100g (or whatever) price, it'd be +/- 10% or something. (That actually is standardised, that funny 'e' symbol for net weight, but the tolerances vary with nominal figure, so I'm not sure off-hand what it is at 100g.)
Carpentry/Construction is done in millimetres (with the occasional length shortened to metres). I've never heard anyone use cm.
Eg: to pay for some timber at bunnings you might say: "ninety by fourty-five. one length at two-four". (90x45mm timber, 2.4m long). On site - if you needed to cut it - you would measure and cut at "twenty-three-fourty-two" (eg: 2.342m or 2342mm)
I thought that there's a slight advantage because some imperial measures are 12-based instead of 10? So it's easier to get 1/6, 1/4, 1/3 or 1/2?
Otherwise I observe that many things like fitness devices look way more bulky when they're from the US. I have the feeling that it's partially because of the system you use, since people tend to gravitate to whole numbers you might say "a 2" bar would be about right" and somebody from Germany would make it 4cm instead. Both whole numbers but the German fitness machine would be sleeker.
In an ideal world we would count 12-based and use the metric system.
Quarters and halfs are as easy (I'd even say easier) in metric: 0.5 and 0.25 and the nice thing is you don't need to convert fractions to add/substract them.
2.75 - 1.5 is much easier for me than 2 and 3/4 - 1 and 1/2
Another advantage is that half cm is roughly a quarter inch, so you usually don't need to go down to quarters, just use wholes and halves (or millimeters if you need precision).
I'm not sure imperial is easier for thirds in practice. I have 2 by 4 inches (5x10 cm) board and want to drill 2 equally spaced holes at 2/3 inches and 4/3 inches into it - how would I do this? There's no 1/3rd inch on an imperial ruler?
All of those qualities you assign to imperial measurement seem likely due to years of use and experience. No one I know who grew up in a metric-only (in practicality, "metric-mostly") environment feels this way about imperial measurement, and they all wax on at length about the elegance of metric, very similarly to how you did about imperial measurement.
It seems that context and experience are more responsible for the comfort with a particular measurement system than anything inherent to any particular measurement system.
Same with woodworking. Dyadics are super useful and American rulers are marked as such, usually 1/16ths. But then trying to do mental math requires base 10 decimals mixed with dyadics, so you get 5's everywhere. Compounding this, dimensional lumber involves lots of multiples of 1.5".
If I could get a natively dozenal (or seximal) calculator with a decent UX, it'd probably be worth it to relearn mental math (common times and divs) in base 12 or 6.
I think another reason it lasted so long is that the inconsistency doesn't matter until you reach a certain level of centralization, are trying to do large projects and measurements and require a given level of precision. Before that you just measure everything for a particular project using a particular measurement conversion and then when the project is done you're done. Also in a more command driven economy precise planning and estimation doesn't matter as much because it doesn't matter if you underestimated the length of the road by 6% because of inconsistent conversions there was more waste in the system than that and people will work on it till it's done anyways.
Another reason is probably the difficulty in actually getting accurate enough measurements in the first place. When you're measurements come from a group of people walking across a plan measuring paces or carrying a metal chain there's enough slop in any measurement and if you're measuring large areas of land you'll be using furlong so you'll convert to furlong-miles. If everyone is doing that the inconsistency doesn't pop up.
Oh, I totally got that the math was bonkers, and it's weird that it took so long to fix it.
My point is that even in contemporary times there's sometimes significant inertia against finally fixing other objectively bonkers measurement systems in outlier communities.
I have no idea how big a hectare or an acre is. Now I know the 100m by 100m bit.
But why don't I know?
No skin in the game. If I owned land then I suspect that I would know exactly how big a hectare or an acre was. If acres were the discussed measurement unit then those would be the units I would use for my understanding, much like how that in the fairly metric UK we still use feet and inches for comparing height.
In the UK people know their height in feet and inches. If you are a guy that is all to do with 6 ft. If you are 5ft something tall you are not 'tall', if you are over 6 foot tall then you are 'tall'. Nobody has the foggiest what that means in centimetres or metres.
There are also practicalities. I am okay measuring things in the garden with a stick. Then measuring that against paving slabs which are two foot or 60cm across. For me the paving slab is the unit. None of this metre nonsense.
Miles are also variable. Due to weather, traffic and foliage you can walk one mile between markers and it be different each time. But that doesn't make the measurement any less useful.
With all these legacy measurements they work great for casual use. Horses height? That will be hands, please. Building height? Storeys. Mountain height? Feet. 100 metres? Well that is 100 yards.
None of it is logical, we are not comparing apples and oranges with these vernacular units, the trick is to use them up to the point where proper SI units are needed.
See them as like the words we use for temperature. It is going to be hot/cold/warm/freezing today is fine, 'today could get to 23.2 degrees!' is just confusing even if well meaning.
That's not exact though. 1ft = 30.48cm. If you are working in your own garden that's probably close enough, but for anything else the errors will quickly add up. Tiles are often made to have sides that are 30cm or 60cm, if you try and tile a bathroom that is 12ft across assuming tiles are 1ft each, you'll get to the other side and end up with an odd piece.
I was born and raised in the UK, and honestly I think we have it worse than the US. At least the US consistently uses the same units (although the wet vs dry weights are confusing). When I learnt to drive I suddendly had to learn what feet mean, even though I'd never used them before in my life.
> I was born and raised in the UK, and honestly I think we have it worse than the US.
Try being in Canada.
Your weight and height are in feet-inches and pounds. When driving though you use kilometres and litres to fill up a tank, but often use miles-per-gallon for measuring car efficiency (though L/100km is popular too).
Most construction is done with US as well (1x6', 2x4'--with the dimensions usually being 'nominal' and not actually those lengths):
Of course no one in the US has a kitchen scale, so most cooking recipes are done via volumetric cups, but baking is done by weight/mass. Of course there are two types of ounces: fluid and non-fluid as well. Preheat your oven to 350F or 400F....
Most people in the US who bake have a kitchen scale. Baking bread and cakes is where I use the metric system, for general cooking I don't weigh ingredients. I scale everything in grams. I don't see how you can use the bakers percent system for bread without using the metric system.
To be fair (I know you were only making a theoretical example) if you have a bathroom exactly 3.60 meters across, you won't anyway fit in it 12 x 30 cm tiles, nor 6 x 60 cm ones without cutting one because of joints between tiles and thickness of the tiles.
As a matter of fact in a 12 feet scenario 12 x 30.48 cm = 365.76 cm it is actually likely that you will be able to fit 12 x 30 cm tiles without cuts (but not 6 x 60 cm ones, unless you put them with very wide joints).
I have always contended that the imperial system of units could increase costs due to how engineers make design decisions. On either system you tend to reach for commonly available increments or standard steps between measurements. In other words, you might think in terms of increments of 1/6 of an inch in imperial and 1 mm or 0.5 mm in metric.
This has consequences that, at a base level, could mean more or less material utilization and at higher levels of analysis affect how structures are designed.
If designing objects with small features, how far apart will an engineer place features when working with each system?
If you are designing bridge, in imperial, do you place diagonal truss elements in, say, 1 foot increments in imperial and 25 cm pitch in metric? Does metric allow for easier optimization in this regard?
Then there's the question of construction standards for buildings. In home building quite a bit of the hardware used is based in the 16 inch stud pitch in standard wall construction, etc.
Not sure if anyone has ever studied and compared standards from the perspective of common design practices for engineers, architects, civil engineers, etc. making design decisions in the context of the standard they are familiar with or decisions imposed by systems of standardization based on these standards.
My solar panels are 2 m x 1 m, which means we had to design a ground mount structure based on that pitch and space rafters on a metric pitch rather than imperial. I can tell you this confused our local building permit office. The plans called for rafters spaced 19.685 inches apart, which, of course, is half a meter. It took a while to make them understand we could not go for 20 inches (which would have allowed them to use standard tables to estimate loads, span, etc.). Measuring half a meter in the context of construction, is, of course, easy, you just buy a metric tape measure and you are done. Using metric dimensions translated to imperial on a plan that requires governmental approval in a place where imperial is all they speak was in a range between comedy and tragedy.
Here's a simple look at how much more or less material one would use when making decisions in metric vs. imperial. For example, an engineer working in metric would choose a 1.5 mm thickness, not 1.59 mm. Her imperial-standard counterpart would reach for 1/16 of an inch. When you compare these two decisions, the metric decision results in utilizing 5.5% less material. This translates into mass, costs, fuel used in transportation, etc.
1/64 = 0.01563 in = 0.40 mm ≈ 0.50 mm 126.0% 26.0%
1/32 = 0.03125 in = 0.79 mm ≈ 0.75 mm 94.5% -5.5%
1/16 = 0.06250 in = 1.59 mm ≈ 1.50 mm 94.5% -5.5%
1/8 = 0.12500 in = 3.18 mm ≈ 3.00 mm 94.5% -5.5%
3/16 = 0.18750 in = 4.76 mm ≈ 5.00 mm 105.0% 5.0%
1/4 = 0.25000 in = 6.35 mm ≈ 6.00 mm 94.5% -5.5%
5/16 = 0.31250 in = 7.94 mm ≈ 8.00 mm 100.8% 0.8%
3/8 = 0.37500 in = 9.53 mm ≈ 10.00 mm 105.0% 5.0%
7/16 = 0.43750 in = 11.11 mm ≈ 10.00 mm 90.0% -10.0%
1/2 = 0.50000 in = 12.70 mm ≈ 12.00 mm 94.5% -5.5%
9/16 = 0.56250 in = 14.29 mm ≈ 14.00 mm 98.0% -2.0%
5/8 = 0.62500 in = 15.88 mm ≈ 16.00 mm 100.8% 0.8%
11/16 = 0.68750 in = 17.46 mm ≈ 18.00 mm 103.1% 3.1%
3/4 = 0.75000 in = 19.05 mm ≈ 20.00 mm 105.0% 5.0%
13/16 = 0.81250 in = 20.64 mm ≈ 20.00 mm 96.9% -3.1%
7/8 = 0.87500 in = 22.23 mm ≈ 22.00 mm 99.0% -1.0%
15/16 = 0.93750 in = 23.81 mm ≈ 24.00 mm 100.8% 0.8%
1 = 1.00000 in = 25.40 mm ≈ 25.00 mm 98.4% -1.6%
1 = 1.00000 in = 25.40 mm ≈ 26.00 mm 102.4% 2.4%
The consequences go beyond the obvious. Here's a real example:
You have to machine a part out of Aluminum.
The part is 0.375 inches thick.
You would think you can just buy 0.375 in bar stock and go for it. You can't. Bar stock isn't flat. You have to be able to take off some material in order to make it flat. You go to Online Metals (no association at all) and see that the next size up is 0.5 inches thick. You are going to have to remove 0.125 inches in order to arrive at your desired thickness. That means you throw away a minimum of 25% of the metal every time you machine this part.
0.375 in is 9.525 mm. An engineer working in metric is likely to reach for 9 mm for this part at this scale. We are not talking about a situation where we tell someone to design a part that is 0.275 inches. The scenarios is one where two engineers are designing parts with similar functionality and each of them reaches for a size based on customary units in each system. This means the part will be made from 10 mm nominal stock and 1 mm (10 %) will be discarded in order to make a flat 9 mm thick starting blank.
Sometimes the thinking goes the other way, with experience you might start with the available material sizes and design parts that fit within the available volume with consideration for manufacturing requirements.
Once you get into large scale manufacturing the differences might not be as significant because with volume comes the opportunity to optimize raw materials, design, etc. My question or hypothesis is more about everything outside of corner cases.
IMPERIAL system was introduced by an expansionist colonial empire and was based on ROMAN mile (the state that was built on slavery and conquest).
I don't think you should choose your units basing on ethics, but even if you do it's not a great choice :)
BTW Napoleon is to this day a hero in some countries (for example in Poland). We even have him in our national anthem :) He temporarily recreated Polish state and freed us from another military dictatorship (Tzar Russia).
I find it funny how he's viewed in English-speaking countries as "almost the Hitler" while Catherine the Great for example is perfectly fine. It's the exact opposite in Poland :)
Two days ago I finished Simon Winder's Danubia (second in his trilogy) -- a tremendously fascinating and enjoyable summary of the history of that region over the past millennium.
That whole region is chock-full of fascinating counter-factual / alternative-histories based on the tiniest 'what ifs' (someone lived an extra year, didn't die of smallpox, didn't choose to build the wrong church in that town that year, didn't stupidly assume an entire foe nation could be defeated in 6 weeks, etc).
From here (Australia, with a generally pro-British syllabus at school) Napoleon is taught as a generally successful, but ultimately bad, force.
The distance components were created (arguably) about a hundred years before bits of Europe adopted it.
When I was in Greenwich (the real one) years ago, our guide told the story, which may be apocryphal, that the Brits negotiated with the French way back about the meridian.
The Brits got to keep the prime meridian by agreeing to adopt metric.
Which they then failed do to do for a couple of centuries (and even then ...).
Unfortunately I can't find anything to substantiate this story just now.
It was at the instigation of the USA and it was partly to do with the establishment of the time zone system, and partly to do with marine navigation charts. Britain had the best charts at the time so there was a significant practical reason to bless Greenwich (with 180° being the second choice).
The French obviously did not like the result, but there wasn’t any quid pro quo about adopting the metric system.
Base-2, like the US Customary volumes, has all the same scaling-made-easy properties, is strictly easier to work with as a maker (dividing/multiplying by two is waaay easier than 10, for, e.g., cutting wood), and plays nicely with computers. This makes it strictly superior on all of your metrics to the SI system.
I suspect you want the US to switch to metric because it’s what you use, not because it’s actually better.
It's not that hard to guess why the broken system lasted so long (delightful and interesting explanation of TFA notwithstanding), and consequently why it was replaced by a different broken system.
95% of people on this planet use, understand, and advocate metric, in which an area of 100 metres x 100 metres = 1 hectare (10,000 sq m).
A 10 x 10 grid of hectares = a square kilometre.
A millimetre of rain falling across one hectare means you've received 10,000 litres of water.
That volume of water has a mass of 10,000 kilograms (or 10 tonne).
Wait a second, indeed!