I sometimes use millitonne (mt) instead of kilogram to keep people on their toes. I’ve learned that some people doesn’t like to have their weight measured in any kind of tonne.
As someone not born to the metric system but who’s tried to lean into it, this is something I’ve always found a little difficult. “A thousandth of a meter” isn’t a useful concept to me. I don’t think we are good at conceiving of things in their thousands, with good proportionality. I would rather just have a singular name like “squajibbles” for milimeters and memorize an intuitive sense of what that is. I realize I can do that with the word “milimeters” too but my brain sometimes gets stuck on unpacking the math. I was reading Dune last night and the expression “millions of decaliters” really stopped me in my tracks. I felt like I had to start with one liter, a sodastream bottle, and multiply it up. I’d rather have some concept like “fuckajiter” which means an Olympic swimming pool and work with that.
Not really being critical here. Metric is better. But intuitiveness is one of the qualities of a measurements system that makes it more or less appealing and I’ve always found imperial has a slight edge there that makes it harder to just drop as a complete loser of a system.
EDIT: yes, internet, I know the only legal thing to say about metric / imperial is that metric is the only system and imperial is for American asshole cavemen. Oh well. Fuck me for offering thoughts from someone trying to move to metric. I should hide my shame.
Wait isn’t imperial the one with asinine fractions?
Like wtf is a 64th of an inch? Or a thousandth (is that how you spell that?)
if you actually use the metric system, millimeter would become that “singular name” you memorize for a certain length. but you could also tell from the name alone what’s it about roughly, squajibbles on the other hand…
I would rather just have a singular name like “squajibbles” for milimeters and memorize an intuitive sense of what that is. I realize I can do that with the word “milimeters” too but my brain sometimes gets stuck on unpacking the math.
This is, in fact, exactly what metric users do in their daily lives… We don’t do math in our heads every time we measure something. We know from experience how large all the units are and pick the one that’s appropriate for a given situation, just like you do.
When you measure something using inches, you don’t then say “it’s this many 1/36ths of a yard” unless you specifically need to convert it into yards for some reason.
Similarly, when we measure something using millimeters, we don’t say “it’s this many 1/1000ths of a meter”. It’s just a millimeter. Don’t get hung up on the prefix, just ignore it and treat it as a unit of a particular size.
I figured that’s what people born to metric do. It’s different when you’re learning it as an outsider, as an adult consciously absorbing the system.
As a Canadian with a living memory of when we made the switch here, I feel your pain. Though to be fair, I was a child at the time and so probably had an easier time of it? But in some ways, I’m still transitioning to this day!
Take temperature, for example. When Canada went metric, all the weather reports switched to Celsius but our indoor thermometers and thermostat were still in Fahrenheit. So I wound up in a situation in which outdoor extreme temperatures became more relatable in C, while typical indoor temperature ranges sounded better in F. I particularly liked winter temperatures in C. It was so intuitive that < 0 means snow and > 0 means rain.
Today, I am more comfortable with C for indoors as well, but not for cooking. I guess that’s because a lot of recipes still say set the oven to 350 or check the meat on the grill is at least 160?
Coming from the UK generation that grew up during the decimalisation process, and therefore being equally comfortable with both systems, imperial measures are far less intuitive than metric. Don’t mistake simply being being used to something as it being intuitive.
We use a base 10 numeric system because that’s how many fingers & thumbs we have. Having a system of weights and measures based on that decimal system, is far more intuitive than a system that scales up through orders of distance using different scaling factors at ever order, is so unintuitive as to be absurd.
Right but if basing things on our hands makes them intuitive, it’s hard to beat “hands” and “feet” for human scale relatability.
As a craftsman, I live milimeters for precision. Very useful and easy to work with. I hate not having anything between centimeters and meters though. I know decimeters exist but nothing’s ever listed that way and so it isn’t something I’ve developed any intuitive sense of.
When I sent some measurements to my uncle to make a bed, I sent it in 200cm x 160cm. Not 2m or 20 dm. You know those exchanges because it’s obvious but since people are used to cm for height, it’s useful to compare stuff with yourself and that’s why cm is the most used measurement for craft.
If whatever you are building fits in a hand, measurements will probably come in mm, because idk why but people enjoy 3 digit measurements.
Me, my wife, my child all have differently sized feet and hands.
Tbh, as an european I kinda absorbed a lot of imperial by just living on the anglophone internet, and honestly have nothing good to say about it.
I can intuitively guesstimate what a mile, yard, foot and inch are in metric, and I do, because it’s useful in my particular corner of the Internet, not because it’s a good system.
I have no idea what a gallon, stone, lbs or oz are. Volume of itself is kinda unintuitive, same with weight. Can’t be bothered.
I dont see a Millimeter as a thousandth of a meter, I see it as a tenth of a centimeter
Scale is what matters. when I measure something in meters I dont care about the exact millimeters
Intuitiveness comes with usage. When I think of a kilometre, I don’t think of a lot of metres, I just think of it as a single unit. A centimetre doesn’t send me dividing metres, I just think of a length about the width of a fingernail.
You just named the main advantage of the metric system as unintuitive and the opposite (squajibbles, fuckajiter, feet, toes, elbows) as the main advantage of the imperial system. Yet, you say that metric is better. I don’t understand. Why do you find metric better then?
I understand that intuitiveness is subjective and that how a person is raised or lectured alters the view on what is intuitive. From a logical perspective, however, I find the metric system much more intuitive as the names of the metrics denote exactly what we are dealing with (except for the case of tonnes). Yes, maybe the wording is confusing. But from the word itself you can infer what is meant, given you know what milli, giga, mega, nano, pico, etc mean. Its just times or divided by 1000. What is feet in miles or nautical miles? Gotta look that up!
Well metric is obviously better for conversions which helps a great deal. I think my intuition problem either goes away with extensive use or being born to it.
I do really like the “foot” as a highly human-relatable unit. At 4 feet tall, a man is aberrantly small or a dwarf. At 5 feet tall, a man is normal but short. At six feet high, a man is tall. At 7 feet tall, he is aberrantly big. It’s a highly usable human scale thing and there isn’t a great analogue in metric. Maybe you get used to decimeters (wait… decameters?) too but they are less commonly used. Giving someone’s height in centimeters has never gotten familiar for me. And the deca/deci thing I think undermines your intuitive point a little. These are easily confused.
I think millimeters and milliliters are great for precision. Imperial sucks below 1 inch or 1 ounce. All fraction bullshit.
So each system has its pluses on intuition. But metric has the conversions advantage and the precision advantage so that’s what wins for me.
The point isn’t to have an intuitive sense of what a millimeter is just by knowing what a meter is. You have to learn both units individually to have intuition about them. The point is to know that a measurement of 500mm is 0.5m without having to do any math in your head beyond moving a decimal point.
Yes but when you don’t have that intuitive sense through extensive use or being born to it, the math gets in the way as you’re trying to form it.
I’m an American in my mid-forties and that has not been my experience at all.
There’s nothing wrong with doing so. Perfectly up to you, and everyone would know how much it is.
A megagram is 1000 kg, by definition. It’s symbol is Mg.
In metric countries, we just use the word “ton” as shorthand/slang for it, since it is an easier term and was well known.
The only reason the US calls it a metric ton, is because they have archaic units (long and short tons).
Metric countries don’t call it a metric ton.
I only use that term when I call a lot of items “a metric fuckton of stuff”
No one in the US knows WTF a long and short ton are. A ton is 2k lbs. And most Americans probably don’t even know the exact weight of a ton outside of “a shit load.”
For the most part, we generally only use pounds, feet, miles. Everything else is a mystery. Even ounces, cups and gallons are some fucking magical mystery. Just follow the recipe.
I switched everything to metric years ago, and have never been happier. It made a huge difference in most of the things I do, having a system that makes internal sense. The only thing I still routinely use standard for is sewing, because it’s damn near impossible to find any patterns or things like cutting mats in metric in the right sizes for quilting.
There recently was a discussion on lemmy where several US citizens (one of them allegedly an engineer…) tried to explain to me that metric might be „more precise“ (? 😂) but the imperial system more practical, because „everybody knows what a foot is“. When I asked them to add feet to miles I got shouted at (in CAPS) that noone (ever) does that. 🤷♀️
I say that Metric is like color vision. You can see things in whole new and easier ways. People in USC can’t understand what others see and insist things are just fine the way they are. Thus the “no one ever does that”, “why would you need to know that”, etc.
It is true that no one ever does that though. That doesn’t mean its not a problem, but I’ve never seen anyone do it. If you need to do something like that and you have a brain, you use metric. Just because its flawed doesn’t mean imperial should be completely abolished though. What needs to stop is people thinking imperial is better than metric somehow. Aside from that, its just a weird flawed measurement system.
We don’t use imperial in the US, we use US customary. Some units have different sizes in imperial. For example, a US pint is 16oz and an imperial pint is 20oz.
That’s how they get you. They make the beer smaller.
I’ll tell you something I do as a woodworker a lot that metric isn’t great for: divide by powers of two, three or four. I’ve got some boards milled up 3/4" thick. I’m going to join them with a bridle joint, that means cutting the middle third out of one and the outer two thirds from the other. So each of the remaining “tongues” are each 1/4" thick. 3/4" is approximately 20mm. That’s a nice metric number, a multiple of 10. Let’s cut that same bridle joint in 20mm stock. What’s a third of 20mm? Can you come point to 6.6666mm on my metric tape measure here?
Don’t pretend base ten doesn’t do stupid things too.
Can you come point to 6.6666mm on my metric tape measure here?
Yes: For woodworkers, it’s identical to 6.5mm, accurately eyeballed at between 6 and 5mm. Don’t pretend you’re a machinist. Does your tape measure even have a vernier scale. Does it make satisfying clicks when measuring. If you have a slip instead of interference fit just dump one piece in water for a second it’ll be fine.
To be more precise, it should be rounded as 6.7 cm, accurately eyeballed at between 6.6 cm and 6.7 cm.
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I saw that too, and many of them claimed they learn both Metric and Imperial British systems and convert between them all the time. So this stood out now:
For the most part, we generally only use pounds, feet, miles. Everything else is a mystery. Even ounces, cups and gallons are some fucking magical mystery. Just follow the recipe.
I mean, it’s true. Ask an American to visualize an ounce of anything other than drugs, and they probably won’t be able to. Ask how many ounces in a gallon, and they’ll Google it. Even cups aren’t well understood. We can eyeball a mile on the interstate, or tell you how tall someone is, or lift a box and guess it’s weight to within 5 pounds. But honestly, that’s about it. We just aren’t really taught to visualize our weights and measures, it’s why newscasters keep saying shit like “8 Olympic swimming pools!” Or “the size of three football fields” because we just don’t have a coherent system ingrained in us. That’s also, I think, why we’re so against metrification. Because weights and measures feel hard, because we’re basically only semi-literate in our own mother tongue, so a “foreign language” feels like it’d be this huge undertaking.
We just aren’t really taught to visualize our weights and measures, it’s why newscasters keep saying shit like “8 Olympic swimming pools!” Or “the size of three football fields”
This really isn’t an American thing - it’s just human, we can’t really visualize dimensions accurately unless we have a good reference. Some may measure the Olympic swimming pool in feet others in meters, but the effect is the same.
Really? … Am I super weird then? Because I can visualize volume and distance really well. I just assumed that was being, like, literate in both systems of measure.
I mean, if you’re converting feet to miles, you’re doing something weird.
How many 39 ft rails do you need to build a 100 mile railroad?
Why on Earth would I ever do that?
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If I was a rail engineer, I would have a chart (or a calculator if its past the year 1980)
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Can you divide 1000 by 39 quickly and easily?
It’s called an example. Want another one? How many laps do you need to run on a 400 m track to run a 10k? How many people can you serve with your 2.5 kg steak if everybody needs to get a 250 g steak? Need more?
Heres the thing, your examples suck because there are no good examples. Almost no one needs to make conversions in their daily lives and those that do have charts and calculators.
Life is not a math problem.
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As an American, I understand that metric is better for a lot of things. It also would cost a metric fuck ton (ha!) of money to switch over, and it just really isn’t a priority when things work just fine for us here. It’s not like we are constantly running into problems that would be easier to solve by using metric, and the people in the few professions that do run into those problems frequently just use metric.
The original idea behind imperial units is actually quite nice. They used 12 inches in a foot because you could divide it in so many ways without using decimals. You can take 1/2 of it, 1/3, 1/4, and 1/6 without ever needing decimals. It’s great for mental math with small numbers. That obviously is no longer the most important thing anymore, as we all have calculators with us at all times, and we deal with much bigger numbers on average than they used 200 years ago.
We all still use 360° in a circle for this exact reason. It can be divided up in 22 different ways (excluding 1 and 360 as factors).
The original idea behind imperial units is actually quite nice. They used 12 inches in a foot because you could divide it in so many ways without using decimals. You can take 1/2 of it, 1/3, 1/4, and 1/6 without ever needing decimals.
You can measure 1/2, 1/3, or 1/4 of a meter, why wouldn’t you? Also, seriously, those common fractions aren’t that hard in decimal. Everybody knows that 125 g is 1/8 kg.
That’s not the issue. The issue is that it’s not consistent between imperial units, you have a zoo of different subdivisions between units. You have 12 inches in a foot, three foot in a yard etc pp.
The issue is it gets really unwieldy in multiplication, 1 cubic ft is how many cubic inches… 1728, how convenient.
Tell me how much is 1/6 cubic ft in inches? How many cups are that? There goes your mental math.
(It is also a common misconception that imperial is „duodecimal“. It’s not. It’s counting to 12 in decimal. If you had a proper duodecimal system, „12“ * „12“ would make 100 not 144.)
We all still use 360° in a circle
And you also say 180°, 45°, 720°. Not 1/2, 1/8, 2.
Ok, I have heard this argument before.
If you go down this rabbit hole, you will eventually realize that it is our base 10 number system that is weak in terms of divisibility. If we counted in base 12, the metric system would follow suit and you’d have your convenient fractions.
In my “perfect world” musings, however, I jump back and forth between base 12 and some power of 2 base. The latter would not be very naturally divisible but would make basic arithmetic much easier. There is a reason computers prefer binary.
The other point I’d like to raise is that even in the imperial system, you are not spared having to deal with awkward fractions, as you will realize when you walk into a hardware store looking for that 5/64" screw. Apparently, fractions are not a deal breaker in this case, so perhaps we should refer to a third of a metre as simply that: 1/3m?
Lol, that sounds very much “as a black man”
I’ll tell you, most of us in the states would love a total switch to metric. We use it where is matters most, but we also have an aging population raised on lead has fumes that think anything they don’t know is “communism” or “wholeness” or whatever else the propaganda right spews. Those are the assholes that pretty much stop progress on anything.
I’m big into 3D printing, actually got into the same argument with another 3D printing guy…. And I’m like, literally EVERYTHING we do is in metric. The whole damn hobby is metric.
I hate humanity
Lol, that sounds very much “as a black man”
You mean the „engineer“? Well, what can I say, he was insisting his professor at uni taught him „a true engineer can work with every system“.
I mean yes, but the difference is one engineer is just happily pushing around decimals, the other one goes pale when you ask what 1/5th of a gallon in cubic inches is…
Hehe, yea, I was poking fun at the “engineer”. There was a congressman a while ago that got caught posting right wing stuff on twitter from an alt account “as a black man” (dude was white of course”
You do realize that the US tried to switch to metric for 6 months in the 70s and it was a giant failure so we switched back, yes? Do you think 2023 America is smarter than 1970s America lol?
You do realize asshole Republicans reverted before it could be more than implemented on a couple of highways
“Metric supporters argued the road signs were a crucial step in helping Americans get over any psychological blocks to switching measurement systems. But Republican Charles Grassley, then a congressman and now a senator from Iowa, killed proposed federal regulations that would have forced states to put up signs in kilometers.”
They literally locked putting up signs in both metric an Imperial
Also… remember my comment about old fucks raised on gas lead fumes…. Yea, the 70s……
Given that the 70’s was 50 years ago, most people don’t know the details of what happened. Other than a metric conversion was attempted.
It’s both surprising and not that it was killed by republicans. And given the current nationalist furor in the party, it doesn’t have a snow ball’s chance in hell of happening in the next decade. If it was proposed, again.
I mean, I’d be very worried if 2023 wasn’t smarter than 1970 no matter the location. Between the lead poisoning and the advancements in knowledge and education methods…
Sometimes I like to think about the logistical challenges with a switch to metric. The one that always gives me pause is highway signs. Thinking about the monumental task of replacing every speed sign, distance sign, and mile marker across the country in any timely period makes my head hurt.
It could certainly be done, and is probably easier than I think with all the state DoTs working independently on it especially over time. We have a lot of road with a lot of signs.
I honestly hate that argument. “it would cost so much to change all those signs” is just negative talk for “it would employee a shit ton of people, create a lot of jobs, and be a major infrastructure project that could help our economy.”. Honestly, the economic benefit of major infrastructure works is rarely talked about as much as it should be. Mainly, I think, because the people it benefits are the ones actually doing the work. And that’s scary to a certain segment of society that would like very much that not to be the case.
That’s a good point, but we don’t have to even fully replace them. I admit I don’t know the name of the technology but I see many street signs or construction signs that have basically a printed metal sticker slapped over the old information.
They are right, no one ever does that. Their reasoning for the imperial system being practical is stupid though. The reason it can be practical is that its useful to have a unit the size of a foot sometimes. Metric is better in general, but there are aspects of the imperial system I would miss if I switched entirely. I just use imperial in casual conversation and metric for anything important.
edit: To be clear I’m not saying conversion from feet to miles isn’t a problem because no one does that, its the opposite. No one does it because its a problem.
Sometimes I think there was a missed opportunity in defining an easy conversion between inches and cm. It is 2.54 cm to 1". Why couldn’t it simply be 2.5? Then a 2x4 from the building supplier could simply be renamed a 5x10. 5.8x11.6 doesn’t quite roll off the tongue as well.
My understanding is that the metre was inspired by nautical measures? So the distance from pole to equator along sea level is supposedly 10000 km. But that’s pretty approximate, and there is a more rigorous definition that involves the wavelength of a certain type of radiation. But that number is quite arbitrary-sounding. Couldn’t they have chosen it to line up with the imperial system at some level to aid migration? Anyway, that train has left the station and I’ll stop ranting now…
At the time when the metric system was created, imperial units weren’t standardized at all, so if centimeters lined up with one definition of inch, they wouldn’t line up with the many other definitions anyway.
Point taken. Reading up on it on wikipedia, I love the the legal definition from 1814, wherein one inch = “three grains of sound ripe barley being taken out the middle of the ear, well dried, and laid end to end in a row”.
Sigh, here we go again…
Yes YOU don’t do that. Because you can’t.
Everybody in Europe can and does so. There’s nothing arcane or mysterious about the metric system. I have no issues telling you how many litres of water go into a 50 x 50 x 200 cm aquarium, or a pool with a 3.5 m diameter and 80 cm height. Good luck doing that with your inches and feet and quarts and gallons.
There’s nothing „more useful“ about either a foot or a meter. Either you know how much it is or you don’t. Everybody knows what a meter is. For me it’s a large step. My arm from elbow to fingertips is 50 cm. Or 1/2 m… A sheet of paper is 30 cm (actually it’s 297 mm, but that’s another story), and so are rulers. Which, btw, is very close to a „foot“.
Your foot btw most likely is not as long as a „foot“, and a small woman’s size is easily 20% off. And no, that’s not „in the ballpark“.
Yes YOU don’t do that. Because you can’t.
I won’t argue that, its a flawed measurement system. My goal isn’t to show you why imperial is so much better than metric, because its obviously not. That doesn’t mean imperial is never useful though.
There’s nothing „more useful“ about either a foot or a meter.
They can both do the same job, but its more convenient to have smaller units depending on what you’re measuring. I find the size of a foot to be convenient for measuring things in casual situations where accuracy and precision aren’t priorities.
Your foot btw most likely is not as long as a „foot“, and a small woman’s size is easily 20% off. And no, that’s not „in the ballpark“.
We don’t literally measure it with our feet, that’s just what its called.
but its more convenient to have smaller units depending on what you’re measuring.
See, that’s what apparently many people don’t understand: with metric you don’t have „larger or smaller units“. You have one unit and you scale it to your needs. It’s not like we have „the meter“ and „the centimeter“ and have no clue what’s in between. There’s absolutely nothing more convenient about having multiple units for the same physical property.
I find the size of a foot to be convenient for measuring things in casual situations where accuracy and precision aren’t priorities.
Again: There’s nothing more or less precise about metric or imperial. You have a mental image of a „foot“ the same way I have a mental image of a ruler or a sheet of paper, i.e. 30 cm.
I don’t really know what a litre is. I know what a beer bottle looks like, or a milk carton, the same way you know what a quart of milk looks like. Pour a quart on the floor and ask someone how much that is, they probably don’t know.
We don’t literally measure it with our feet, that’s just what its called.
Oh, I definitely had other people tell me imperial is „more human“ because a foot is the size of your foot and an inch is the size of the tip of your thumb.
with metric you don’t have „larger or smaller units“. You have one unit and you scale it to your needs.
That’s the same thing, the units are just proportional.
It’s not like we have „the meter“ and „the centimeter“ and have no clue what’s in between.
I know, its just easier to say a foot than 30 centimeters. That’s why I use it in casual conversation, and not in anything important.
There’s absolutely nothing more convenient about having multiple units for the same physical property.
That’s not the part I’m saying is convenient.
Again: There’s nothing more or less precise about metric or imperial.
They can both be used to measure things precisely, but metric is more convenient in those situations usually. If I need to accurately measure something, I would use metric because the advantages of imperial are probably not applicable. If I’m just estimating and it doesn’t matter much, I’ll probably use imperial because I won’t have to do any conversions with that number, or anything else imperial struggles with.
Oh, I definitely had other people tell me imperial is „more human“ because a foot is the size of your foot and an inch is the size of the tip of your thumb.
Those people are wrong.
I wish decimeter was used more commonly. It kinda takes up the place of the imperial foot.
lbs = elbows? 2 thousand human elbows?!
Yes. Jesus, why can’t Europeans educate themselves on real measurements! We measure in feet and bald eagles for distance. We measure in shotgun shells, elbows and pounds for weight. We measure in ATNT for temperature. That’s Ambient Truck Nut Temperature, which is the temperature of a pair of truck nuts after driving for 80 bald eagles at 40 bald eagles per Active Shooter Warning, at sea level on a Wednesday. It’s not complicated.
We call it a metric tonne in Canada.
There’s also short ton and long ton which have to be differentiated, but no one ever knows which one they are using.
That’s because you only metricated 40y ago.
Damn, you guys might be worse than the British.
Something like this? How to measure like a Brit
I don’t think this is 100% accurate tbh
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Yeah, but what about the metric shit-ton?
I always forget- is that 100 fuckloads?
I think it’s 128 fuckloads.
Canada does, because we’re mostly metric but still do enough business with the US that we’re sorta half and half
Megagram is the official SI term for the weight. Metric tonne is non-SI but happens to be equivalent to a megagram and became the more common parlance (where I am, at least) by historical accident.
Pretty sure they tried to mimic existing units/terms to make it “easier”. So they used tonne to mimic ton.
They didn’t mimic existing units, an imperial ton is close to a metric ton, and the spelling tonne is just an alternative spelling of ton. In some parts ton means imperial ton, and tonne means metric ton, but it’s not standardized. In German, where the word originally comes from, it’s Tonne (btw the e is not silent, it’s [ɛ] as in let. Or in Porsche (no, it’s not pronounced porsh…).)
They mimicked existing terms, otherwise we wouldn’t have ever had the term metric tonne. It would have been called a megagram.
I’ve often wondered why the kilogram was not called the gram when the former is commonly cited as the official unit of mass? I guess it doesn’t really matter much since it’s easy to convert between units. That’s sort of the point of metric, but still…
Cuz the gram came before the SI system and the kilogram is a much more useable unit. The original m-g-s are based on physical things, like m being a subdivision of the length from the North Pole to the Equator going through Paris, and s being related to the time of a pendulum with certain length swinging or smth
A gram is the weight of 1 mL of water, roughly.
I remember in some old astronomy textbooks they used units based on CGS (cm-g-s) as opposed to MKS (m-kg-s). It was pretty weird, as they had terms to go with that system like dynes instead of newtons for force. But at least it wasn’t imperial.
Which is 1 cm³ of water if we want to stay in SI. And if that’s the basis for it, then why not make a gram = the weight of 1 dm³ of water and then we wouldn’t need a prefix for weights in the stuff-we-usually-carry-around range. It still doesn’t make sense to me to have a prefixed unit being the base unit.
A cubic meter of water should have been a liter and weighed a gram.
Apparently it was going to be, but they chose the kilogram instead.
Fair enough. But it’s interesting right? Like the litre lines up with the kilogram (for fluid measures) but they don’t call it a kilolitre for consistency’s sake?
This is one of two “warts” that I know of in SI. They wanted a coherent set of units, coherent meaning that no nuisance constants are required to convert between dimensions in the set. The system at the time was gram-centimeter-second. To expand things to all dimensions I suppose it was simpler to use the larger units, like J = kg m^2 / s^2 rather than trying to make a new unit for energy, etc. You’d think they’d have just come up with a new name for mass units and defined it as 1 kg, something like 1 prot = 1 kg, then all of the coherent units would be ones without prefixes. Someone must have really being going to bat for the word “gram” though, because now we have this pretty stupid rule that the coherent units are all of the ones without prefixes, except mass, which has the coherent unit of kg. And then also, prefixes are used to scale the coherent units by appending the appropriate letter to the coherent unit symbol, except for mass, for which g is treated as the coherent unit, even though it’s not.
It’s not the worst thing, but it’s pretty stupid to explain.
until you realize, that “second” is also not the base unit. it’s not at obvious because it isn’t metric, but second is just the second subdivision of an hour (the first being the minute)
There are no longer any base units as of the 2019 SI redefinition, but prior to that the second was the base unit for time. Hour and minute we’re defined based on that. And now even though a second isn’t a base unit, hour and minute are still defined based on the second, not the other way around. It’s been that way for several decades now. Maybe you’re thinking of some no-longer-used system.
Okay I’ll bite. What’s the other “wart”?
The mole is defined based on the gram and not the kilogram, even though the kilogram is the coherent unit of mass. I don’t have an example, but it probably results in a bit of extra math somewhere. Again, who knows why. Apparently the mole has had conflicting definitions in the past, and one of them was based on the kilogram, so it seems like this would have been easy to do. Again, the gram is involved - maybe the two things are related?
Apparently, the SI base units have been redefined, and the link between moles and kg was severed in 2019?
I was vaguely aware of this shake-up after reading someplace that the kg had a new definition in terms of fundamental physical constants rather than the old one based on an official standard kg. This was basically a block of metal sitting in a lab someplace in France. But TIL other base unit definitions were also tweaked at that time.
Units closer related to everyday stuff are those that stick around. Like horse power or km. People don’t use Mm but instead 1’000s of km, even into the million km for cars. Even in space they still tend to use km like for the distance to the moon or sun. Only once the distances get absurdly large is there a shift to either another unit (light years) or the use of different notation (like 3.14E12 m).
I know the metre has been defined by earth’s size, or other various things, all rather arbitrary. Wouldn’t it make sense to define it by the speed of light and a light year, divided into even portions? Start by dividing a light year (in a vacuum) by ten, and keep dividing by ten until we get a unit that is close to the useful size we are accustomed to?
That way we could scale up, and I suppose that’s going to be useful in the future.
It’s already defined that way - from Wikipedia "From 1983 until 2019, the metre was formally defined as the length of the path travelled by light in a vacuum in 1/299792458 of a second. After the 2019 redefinition of the SI base units, this definition was rephrased to include the definition of a second in terms of the caesium frequency ΔνCs. "
Just because it’s defined as some section of a light year does not mean it’s using a light year as a reference. You could use a foot and find the fraction of a light year that represents it, but that doesn’t mean that the foot is based on a light year.
I’m saying the short measure that we use on a daily basis might be a BASE 10 portion of a light year. Not 1/299792458 of a light second.
P.S. It’s like being on Reddit, being download for conjecturing.
As a Swede, using units that give numbers above ~100 starts to get unwieldy. Hence why we use mil (1 Scandinavian mile = 10 km) once we get to triple digits in km. “It’s 60 mil to Stockholm” is immensely more natural than “it’s 600 km to Stockholm”.
That is fascinating! I had heard of the “metric mile” as being 1500m: the closest you can get to running a statute mile at international competitions.
But I like this 10km mile idea! We could use something like that here in Canada. Sometimes we say “klick” here to mean km, so I have tossed around terms like “decaklick” and “hectoklick” but people look at me funny.
We’ve had different mil definitions in Scandinavia before, but at some point Sweden and Norway agreed to unite at 10 km, which is a really useful unit. Denmark just didn’t do it. They’ll give distances in hundreds of kilometers.
I love this! Let’s use all the prefixes!
It’s always been a pet peeve of mine that Sweden is seemingly the only country that uses dl (deciliter) and hg (hectogram, but we just say hekto, just like with kilo), which are to me vastly more useful units as they’re close to what you’re measuring. 2 hg salami or candy or whatever instead of 200 g, and 3 dl water instead of 30 cl or, god forbid, 300 ml.
I see cooking shows from countries that normally use imperial, using metric by measuring everything in milliliters. It makes no sense! No recipe needs that resolution.
The astronomical unit AU is commonly used for things in the solar system. 1 AU is roughly the average distance to the sun, about 150 000 000 km
I like metric wrenches, if my 5mm doesnt fit I can try the 6mm. Most nuts and bolds are not metric, so I end up figuring what comes next if my 1/2" doesn’t fit. is it like 33/64th? 34/64th? 17/32nd?
But then what would a metric fuckton be?
A Megafuck.
Yes I require 10 Megafucks of gravel to finish with the landscaping
2.2 shitloads.
I’m an engineer, and I make it a point to teach young engineers that “a ton” can mean any one of three things:
- Short ton = 2000 lb
- Long ton = 2240 lb
- Metric ton = 1000 kg = ~2204 lb
And which is being used is often not spelled out, but is just known from context, and usually should be clarified. I once nearly got in trouble by thinking a measurement was in short tons when it was actually metric tons.
So my own act of rebellion is to use “Mg” when I’m writing my personal notes.
There is metric ton and this imperial shit. And thanks to metric being highly systematic, “Mg” (megagrams) is actually correct - “ton” is just a shorthand.
One magnesium please. yes I’m sure, only one.
I prefer Gigamilligram
After reading the comments, I’ve noticed a point that is missing from the other comments. We like to measure things relative to other things. Therefore we should use a unit of measure which you can compare the entire range of expected values for that question simply.
For example how far away is my nearest town centre? 1km. How far away is the nearest city? 10km. How far is it across the country? 500km, How far is it across the continent? 5,000km. How far is it around the equator? 40,000km.
By using all km in this case it’s easy to get an idea of the relative distances. But you wouldn’t measure your height as 0.0018km. Just my own thoughts!
Lol imagine a country only 500km across.
You measure your height in metres as in 1.8m or 180cm and for little things it’s mm (millimetres) or cm if it’s less then 1m.
It scales alot easier then the US measurement system of anything other then the simple metric system.
That’s what unit prefixes are for… you can measure your height in cm
Exactly!
Sounds good to me 👍
Seconded. Who do we need to update?
I’ll call the king!
Ummm… I seem to have misplaced the number.
No worries he prefers email these days
Earth’s circumference is 40 Mm. 1 AU is 14 Gm. I could get used to this.
The moon is 400Mm away. Never say thousand kilometers again, the mega is the way.
Imaging if we started saying millions of kilobytes instead of GB.
The Andromeda galaxy is ~23.6 Zm away. The metric system reaches far.
I love that ‘ton’ has different meanings in different contexts. Sometimes life isnt exciting enough
