this post was submitted on 31 Mar 2024
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It's easier for handling real things.
Try doing woodwork in feet and inches for a day. Try it in metric for a day. You'll see what I mean.
It was crafted for the human-scale, whereas metric was worked out on paper by French philosophers.
Human scale? Not yours or mines, measures of the ffoot, thumbs and random desires of a dead British King in the far past. No problem in metrics, at least if I don't build a hut in the wood with an axe, then maybe using parts of the body for measures are usefull. Not the first furniture I made, also working in metal. Also in mathematic and physic the metric system is way better (Even NASA now uses the metric system since 2 probes crashed on Marte due to calculation errors in the imperial system)
Just wait for an American to tell you how it's easier to use fractions with imperial. I've legit seen them say shit like 3/8 of an inch is easier to think about than 9.5mm.
Above having to add 3/8, 5/16 and 2/3 inch ¬¬
2/3 is not a valid fraction of inches.
Valid denominators are 2, 4, 8, 16, or 32. Technically, 64, 128, and 256 are also acceptable, but they are never actually used. For precision greater than 1/32nd, we switch to thousandths, or tenths of thousandths.
3/8 + 5/16 is 11/16ths.
Quick off the top of your head, what's a third of 9.5mm?
~3.2mm. I can't think of any real world application which needs fraction of a millimeter which doesn't include ah calculator and some damn exact measuring tools.
Quick off the top of your head, why would I use fractions of a cm instead of mm? It's a workaround for a shit system
Well I'm building a table right now, and it was pretty easy to choose a size for a mortise and tenon in my 3/4" stock, a third of 3/4" is 1/4". If I wanted half its width, that's 3/8". Mental math is a lot easier than "What's a third of 19mm." In the wood shop, I rarely have to divide things by five or ten. I have to divide things by two, three and four a lot.
I don't know anything about carpentry, so I'll take your word on it.
My best guess is that the standards are different. For example 2cm stock instead of 1.9. Then only the 1/3 is problematic.
I'm building a shaker table out of white oak. I milled all my stock to 3/4" thickness.
Just today, I resawed a board to 3/8", or half its original thickness. I glued two boards together to make 3/2" (1 1/2") thick table legs, and I cut mortises 1/3 the thickness of the stock, or a nice even 1/4".
I'm familiar with the metric system, I learned chemistry and physics in metric. I prefer woodworking in fractional inches because metric seems like a bigger pain in the ass
We are communicating through writing on an asynchronous web forum.
what's a 1/3 of 1/8th of an inch?
1/24th.
Fractions of fractions are easy, just multiply the denominators.
okay then my answer to the hypothetical is 9.5/3, which is every bit as easy to find on any measurement device, or to use for any practical purpose, as 1/24th
Well I’m not the person who initially asked you that, I’m just someone who recognizes how easy it is to work with fractions.
Also I have a ruler with 1/12s graduations and while it’s not 24ths, my neighbor has one marked like that.
E: my drafting ruler has a short 24ths scale
so in other words you're helpless in that situation?
we can play the same game with 1/18th or whatever if you want
No, like I said in my edit, my drafting ruler has a three or four inch long 24ths scale.
Even if it didn’t, having to mark the halfway point between graduations is hardly helpless.
18ths would need two divisions by three, but thankfully dividing a known measured length by three is easy with a piece of string.
There’s a reason millennia of our ancestors used fractional divisions of standard lengths and weights. They can be measured, calculated and double checked (this one is doubly important for stuff that really pisses off metroids like the hogshead/tun) using cheap, universally available tools and deceptively simple mathematics that have been the foundation of what constituted a good education for centuries.
what kind of cartoon fantasyland do you live in where it's easier to find a piece of string than it is a calculator?
also, all of this is assuming you have your drafting ruler to hand
do you carry it around with you in your pocket on a day-to-day basis? some deep fucking pockets you've got there, although I suppose you already that to the 1/24th inch
my guy, we're talking about accuracies of millimeters here: you're not "double checking" your 12" ruler is accurate by slapping your bare carpet gripper up on the drafting table
we no longer live in the pre-industrial age
well, considering i was sitting in the bathroom looking at my phone while wearing clothes when i saw your response, i'd say string and a calculator were both equally close at hand.
only one of those can be used as a measuring tool, though... I guess you could mark off how many calculator lengths something is and measure it later. ngl, i hung a shelf using that technique once, but i wouldn't use it to find one third of a length. the nice thing about string is that if you don't have a measuring stick you can always stuff it in your pocket and measure it later when the appropriate tool is at hand.
apologies for any confusion about checking measurements, i wasn't referring to using my own foot to verify the length of a line, but the common practice of using fractional mathematics to make and verify calculations thousands of years ago and to this very day. we have records of this method being used across language and unit barriers in the ancient world.
there's another post earlier itt blaming the mars climate orbiter failure on sae unit conversion but nasa puts the blame on itself for not double checking the software and measurements they got back from lockheed. I remember back in the day hearing about that failure on the news and seeing how it was not a problem of difficulty of conversion between the compound units involved, but failure to actually convert between them at all!
since you brought up calculators, there's a salient point to be made here using a long winded anecdote: when i was in school there was a point in time when suddenly teachers began providing calculators for the exams. this wasn't that magic moment when the mathematics became just too complicated to expect a middle schooler to do it all on paper. last years class had to use longhand, this years class were provided little blue texas instruments scientific units with a ten digit display and helpful guide to performing logs and other operations that would have been taught using super and subscripts glued to the inside of the cover that would be taken back up at the end of the test.
this didn't happen going from one grade level to another, but right smack dab in the middle of the academic year. a whole classroom of students yanked bodily into the digital age.
when the parents found out you'd think the questions were gonna be written on the proctors inner thigh. "i had to do it by hand, my kid should too!" "you're supposed to be teaching them math, not how to use a calculator!" and it's sister "you're supposed to be testing their ability to do math, not use a calculator!" but the most common one by far was "they'll all just get the right answers and we won't know who studied and learned."
when the grades came in there was almost no change from last years class.
there were some individual students who did better or worse than their test history would suggest and a whole bunch of new common wrong answers, but by and large aside from errors the ability to perform calculations in response to a prompt was unaffected by ten signed digits of precision.
how could it be that a calculator made no difference?
it turns out that understanding what a question was asking for, verifying ones work and recognizing wrong answers that needed to be rechecked couldn't be performed by the little blue rectangles.
and many years (and measurements) later i have the same outlook about metrology: comprehension of the goal of a measurement gives you a much better chance to get it right than a calculator.
i don't really like replying to such a long comment with such a short one, but i feel like i need to remind you that the thing that started this chain was
reaching for a string in that situation would be puzzling to me
string would be tough at that scale but weirdly might be easier to make that measurement with than a ruler. just cut your string to 9.5mm length, then divide it by three, one of those divisions is your target length and you even have the other two to check your division's margin of error against.
to calculate and measure with a ruler would have you measuring 3.16666... which i would not be able to measure with a ruler. now a vernier caliper would be the right tool to make that measurement, and even if mine only had tenths of a millimeter id just round to 3.15mm and mark in between the mm graduations when forced to use that group of tools.
of course that's if you know how to use a set of calipers. its not as easy as one might think.
lets not forget that your response to the one third of 9.5 conundrum, which was posed by a metric defender, is:
which is literally not true as i have explained about the 24th scale ruler and even my digital calipers don't do repeating digits or express portions of metric measurements in fractions.
of course, in a real world situation i'd never be trying to mark 3.1666...mms because it's 1/3 of a thou under 1/8 inch. i'd just mark an eighth of an inch like a normal person.
even using a calculator to figure out the length suggests that a person in that conundrum stop using the metric side of their ruler.
they weren't a metric defender
what scenario is there in your mind where you'd need a precision answer to what 1/3 of 9.5mm is, but also not have access to a calculator? and of those scenarios, how many of them would be solved by the knowledge that 1/3 of 1/8 is 1/24? i'm willing to bet the answer is more or less "none".
and for those that do exist, you can also get drafting rulers that give you 1/3rds of metric measurements.
the accuracy of your equipment isn't somehow better because you're dealing with fractions rather than decimal points
you're right. the person who initially brought up 9.5 was comparing it to the sae equivalent 3/8 (9.525mm, but whos counting).
the reply was what i was thinking of, the obvious answer: "what if you need to divide by 3?"
so good eye.
one scenario when i'd want a precision answer to 1/3 of 9.5 but also not have immediate access to a calculator is when woodworking. you know, seeing as how 9.5 is (the actual metric defender this time's approximation of) 3/8... and there's no way that a calculator would help me there because the result of 9.5/3 is 3.16, a length i'd need at least tenth millimeter vernier calipers to accurately scribe. even 9.525/3 is 3.175, a measurement that requires um precision to scribe!
the inch side of my ruler, however, is graduated in eighths of an inch and i can make that measurement easily with it.
i've also used a third measurement of a known diameter when drilling holes in metal to use a technique described in machinerys handbook to cut slots.
you were the one who asked what a third of an eighth was. i'm not sure why. why did you bring up a third of an eighth? was it because you thought it would allow a person to more easily answer the question what is 1/3 of 9.5?
i guess my real question is this:
how does a calculator help you make more accurate measurements?
using a ruler to measure a length of 1/8" is as accurate as using a ruler to measure a length of 31mm and eyeballing 2/3 of a mm
the bottleneck at that point is your eyeball and pencil lead, not the unit of measurement
well, it's 3.16 mm, not 31.6, but i get your meaning.
in that case if you wanted to be real precise, you'd measure from the left or right side of one graduation to the same side of the next graduation. using that technique a person could get a better 1/8" off a ruler than someone eyeballing fractional mms would.
I still don't see how a calculator helps though.
well yeah, because 1/8" is 3.175mm
1/3 of a mm is a distance between 1/64" and 1/128"
mechanical pencil lead is only about 0.4mm
don't ask me ask the person who posed the "what's a third of 9.5mm" question
Usually when I’m making a precise line, I’ll put an edge on the pencil lead so it will make a mark thinner than its diameter.
I seem to remember you as the one who brought up calculators, but I’m open to being mistaken.
even if you're in a situation where it's somehow possible to manually draw 1/3 of a mm to any accuracy, 1/3 scale draft rulers still exist for metric, so it's equivalent
because as soon as you have access to a calculator, "off the top of your head" is an irrelevance
You know what really gets me about these threads? Everybody being like "Can you believe Americans are stupid enough to comprehend fractions? I'm too smart to comprehend fractions."
thinking that knowing that 1/3 * 1/8 = 1/24 is something that anybody wouldn't know is stupid
the point is the impracticality of the result being essentially equivalent to 95/3
I doubt it had much to do with kings, as they didn't do handicrafts or have to measure things like grocers/traders do.
That image is really stupid, too much wrong with it to go thru.
I am willing to bet that you are simply more used to the imperial system.
I am not convinced that it has any objective advantage over the metric system.
My foot is about 50% larger than my SO's, but I can perfectly invision 30cm whenever I want or need to.
Cooking too. Try baking a cake in the two.
Pounds-and-ounces is all like "two eights is sixteen", "three threes is nine". Nice and handy multiples is what it's made on.
I'm about equally familiar with the two.
Woodworker in US here, and I prefer metric. Also consider the thickness of plywood is actually in metric now - "3/4" is actually 18 mm but they have to market it as 23/32.
I've chosen to join the other 8 billion people on earth.
Are you telling us that you are actually making, say a box, by measuring it with your hands and feet? That’s barbaric! I’m guessing you actually use a tape measure like the rest of us.
You and @Zerush both resorted to this fake idea that [not using the metric convention] = [measuring things with your body-parts]
Very weird lie. I'll take it as an admission you're out of sensible points.
That is what you’re implying by saying that imperial is more intuitive. But if you’re measuring with normal measurement equipment that argument is moot. At that point using imperial is easier for you just because you’re used to it. When normal people have to use imperial for things, all intuition is out the door and it will be hell.
You’re failing to externalise your own experience from the situation. Maybe you should practice that a bit more.
Dude, WTF are you talking about? When I was a machinist it was so much easier to deal with metric. 1 inch ~ 25 mm, from there it is just way easier to deal with measurements such as 27.5 mm instead of 1 5/64 inches and all of these inverse powers of 2. I was always jealous of the French machinist I worked with talking about how the only units you should ever have to work with is meters and millimeters. If you are concerned about "Human Scale" then intuitively a meter and a yard are close enough for estimates and you don't have to deal with "wait, what is 5/8 + 3/16 + 1 7/64?"
Those are so easily commensurable! It's 1 and 59/64 obv.
It's set up to make this easy.
Let me ask: do you think people have usedit for hundreds of years for no reason?
I legit can't tell if this is sarcasm.
In binary it's 0.101 + 0.0011 + 1.000111, or laid out vertically:
Halving numbers is no harder than decimating them, probably easier for most of us. Even computer scientists don't think of base-10 as The Way The Truth and The Light; they use base-2 or base-16 for various things.
Decimal/base-ten is fine as a convention, but insisting that One Convention is perfect and others are heretical is stupid.
You do you, but if you're reverting to binary to explain how simple it is to add values together, I think you've made a wrong turn somewhere.
halving is a really easy mental operation; we do it all the time mentally and with physical things like bits of food or drink or folding a piece of paper
Let me also ask, do you think the rest of the world moved away from it for no reason?
Woodworking, sure. You have a piece of wood 2' 5 5/8“ long that you need to cut into quarters. Can you calculate that in your head? Metric is SOOOO much easier.
here's how i did: 2'/4=6", 5 5/8"/4=1 13/32, so it's 7 13/32"
smart to pick a prime numerator!
Alternatively, the same measurement is 752.5mm / 4 = 188.1mm, to a practical number of significant figures. No convertions between feet and inches (or ridiculous fractions of inches), and only one calculation.
Yes but my measuring tape actually has 32nds on it. The meter side only has whole divisions, not tenth graduations.
So the sae “ridiculous fraction” is a measurement I can easily make with tools I have on hand to the tools own limit of precision and double check in my head with five seconds of fifth grade level mathematics while the metric one can’t be actually measured without a set of calipers and honestly would merit long division or a calculator to double check and still needs rounding off a vile eighth of millimeter to hit what is in your own words “a practical number of significant figures”.
Imma throw something out there and I hope the earnest admission that I can’t divide 752.5 by four in my head with the level of confidence required to cut materials by is enough to recognize it not as an attack but as a real grasp at understanding:
People who make posts like yours either don’t measure things in any meaningful way (cutting, dividing, scribing lines, etc) or don’t know how to work with fractions.
Like I said: it’s not an attack, I just can’t see how someone would suggest that the metric equivalent to 13/32 is easier to work with unless they didn’t intend to actually measure it or couldn’t do fractions.
I like imperial for big things. like you said it's easier. For small things like 3d printing and such I prefer metric (basically anything with increments smaller than 1/16"). It just depends on what scale you need to work on.