1y ago

Why a ton, and not a megagram?

101 comments

I think it's written 'tonne'. And you should call it metric tonne if it's not clear from the context.
Wikipedia says:
The tonne is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton (United States customary units) and the long ton (British imperial units). The official SI unit is the megagram (symbol: Mg), a less common way to express the same amount.
https://en.wikipedia.org/wiki/Tonne
So yes, you can call it a megagramme and you'd be right. But we european people also sometimes do silly stuff and colloquially use wrong things. For example we also say it's 20 degrees celsius outside. And that's not the proper SI unit either. But that's kinda another topic.
- It's typically shortened as t. So a mass of 1,000,000 kg will be referred as 1,000 t
  Normally it's clear from the context and what units you are using so there is no ambiguity.
  
  I'm not so sure. But maybe you're right. I think I was confusing that with tonnage of a ship. But that's a whole other concept and you can't really confuse the two.
  With the 1000 t thats only because kg is a stupid SI unit and leads to the whole debacle. If there wasn't a prefix in the unit name itself, I think people would have started to use the SI unit prefixes correctly at some point instead of inventing and omitting other names to compensate.
  I think I've heard things like megatonne. For example you can say your nuclear bomb has X megaton tnt equivalent.
  A mass of a million kg should be 1 gigagram or 1 kilotonne. Not 1000t. (Edit: And not a kilotonne either, rather a mega-kilogram.)
- For example we also say it's 20 degrees celsius outside. And that's not the proper SI unit either
  Can you elaborate on this? As an American without much experience with the SI system, I wouldn't think twice if someone said this to me
  
  The SI unit for temperature is Kelvin
  
  What would you like to know? Regarding temperatures: 'Kelvin' is the proper SI unit. It starts with 0 at absolute zero. And then uses the same size for units as celsius uses. So 0°C (the point at which ice made from water melts) is 273.15 Kelvin. 20°C about where you'd wear a t-shirt is about 293 K. So we don't say it that way but keep saying it's 15 or 30°C outside.
  Scientists do it right. When you're melting metal or talking about the temperature of the sun, you won't have small numbers anyways and you won't benefit from using celsius. That way you'll have the 0 at the true 0 and aren't arbitrarily using water at earth's atmospheric pressure as your basis. You can translate it easily, anyways. Just add and substract the 273.15. You don't need a formula and a calculator like when you translate between fahrenheit and celsius.
- Wait, what’s the correct SI unit for 20 degrees Celsius then? I’ve never heard anything besides that.
  Edit: Nevermind, someone already asked the same question as me a bit further down. Disregard this question.

No good reason, just historical inertia and resistance to change. People stick to what they're familiar with, either the imperial system or to common metric units. Making a "metric ton" similar in size to an "imperial ton" arguably helped make it easier for some people to transition to metric.
Megagram is a perfectly cromulent unit, just like "cromulent" is a perfectly cromulent word, but people still don't use it very often. That's just how language works. People use the words they prefer, and those words become common. Maybe if you start describing things in megagrams other people will also start doing it and it will become a common part of the language. Language is organic like that, there isn't anyone making decisions on its behalf, although some people and organizations try.
- The sort of person that insists on calling a ton a megagram is probably going to be the same sort of insufferable Jimmy Neutron arsehole that insists on calling salt "sodium chloride".
  Yes you're technically correct, but people experience food as salty, no one is going to say "this food is very sodium chloridy!" and it's the same situation with tons and megagrams
- Similarly large volumes of water should be given in kl, Ml, Gl etc. instead of m^{3. Which one is bigger 2500000 m}3 or 790000 m^3? Count the zeros if you want and then tell me if using appropriate prefixes would have made it easier to tell the difference.
  
  If you see an IBC of water, do you see 1m³ or a thousand individual liters?
  There's nothing wrong with describing things the way that you experience them. It makes sense to use which ever units express the idea most simply.
  
  If you used scientific notation or commas (or periods, depending on region) to format those numbers for human consumption, that would also make it easier.
- I think there is even a metric inch defined as 25mm (for pipe diameters etc)
- There is a good reason.
  People can picture one ton in their heads, no one can picture one million individual grams.
  You can imagine a ton bag of sand, you can't imagine one million individual grains of sand that weigh one gram each.
  The term "megagram" does make perfect sense, but it doesn't fit well with the way the people experience the universe around them.
  It's the exact same reason that weight is the only SI unit where the kilogram is the standard rather than the gram. You can imagine holding a kilo in your hands (about 2.2lb if you're American) and you could easily tell the difference between 1 and two kilos, or 1 and 0.5 of a kilo, but if you hold a gram it feels like nothing, and you probably wouldn't be able to sense a difference between 1 and two grams etc.
  Edit: didn't think explaining that people like to describe the universe as they experience it rather than being pedants about measuring weights to the precise gram every time would be an unpopular opinion lol
  
  These two words mean the same thing, why would you be able ti picture one thing but not the other?

Two relevant details:
The OG metric system (from the XVIII century) had no prefix for 10⁶. "Mega-" would be only formally acknowledged by the SI in 1960.
The ton units (yup, plural) backtrack all the way to a volume unit from the Middle Ages, the amount of liquid that you'd be able to put in a big arse cask
Based on those two things, I think that the ton was standardised to 10⁶g considerably before the name "megagram" had the chance to appear, to the point that it became the default name across languages.
I don't know the English name for the cask [EDIT: "tun" acc. to @theplanlessman@feddit.uk ], but in Portuguese it's "tonel". From that "tonelada" (the unit). It used to be 800kg before the metric system though.
- FYI the English name of that cask is "tun".
  
  Thanks for the info. (To be honest I couldn't be bothered to look for it.)

I brought a shit ton of tacos. Or I have supplied us with a faecal megagram of tacos. You be the judge.
- I am shocked by how well your latter example emphasizes an extremely large quantity of tacos.
  I vote for that one.
  
  The funny thing is that one taco makes a faecal megagram, if it's the right kind of delicious, filthy taco.
- An imperial shit ton or a metric shit ton?

I'm all for megagram. If nothing, it will stop the senseless people that insists on using imperial unities from confusing everybody.
- WE MUST HAVE IMPERIAL UNITY!

Mega pints are more fun.
Okay in all seriousness, though, the “ton” has been in use for far longer than the gram or the metric system .
- The fuck ton being the oldest example
- Next time I'm at a pub that does megapints, I'll ask how they managed to squeeze 10^6 pints in a 2 pint glass.
  
  Beerspace. It's like pocket space, but for beer.

Apparently megagram is the correct term! Someone else was just posting about another metric question and they posted some historical reasons for why megagram never took off.
That car weighs in at 6 megagrams.
Yes.

More-common terms in any language tend to be shorter or at least less standard/more irregular.

i do see Mg instead of t in publications sometimes

Also, same issue as with MB and mb, you might confuse megagram with milligram
Although that's not really the reason, more like an argument to keep it this way
- And you might confuse MB, megabytes, with MiB, mebibytes. MB is typically used to measure storage, and MiB typically used to measure data. There's 1000 bytes in a kilobyte, and 1024 bytes in a kibibyte.
  
  I still use mb and kb as 1024 instead of 1000, because I prefer to not have units switched around from under me. 2^16 will always address 64kb, not 65.
- Mega mean 1024 of something right?
  
  Mega is a million. Kilo is a thousand. 1024 in kilobytes comes from powers of 2 which are more natural in addressing computer memory

A really big grandmother

The official unit name is megagram. Ton is just used much more commonly.

I've never heard of gigameter or gigalitre

Why a feet and not a fivger ?

If you think about it, tonne is actually a better base unit than grams, because it aligns better with the cubic metre (1m^3 = (approx.) 1 tonne of water.)
So really, I would ask why kilograms and milligrams, and not millitonnes and microtonnes?
I can picture it now. I weigh 70 millitonnes.

There are about a million reasons.

Because "ton" was an established amount in trade and shipping (though with significant local variations), that was later adjusted to fit into the metric system and standardized. Hence why people specify "metric ton". There was simply no need for people to change their terminology when they already had good monosyllable.
Similar to "mile" which in metric countries were brought into the standard and defined to be 10,000 meters. While these days kilometers are almost always used for long distance in all official uses, people's habits are still to talk about "miles" when describing how far something is to travel. E.g. "I live roughly 2 miles from town" flows better than "I live 22 kilometers from town".
Edit: Recent example use of metric mile: https://www.nrk.no/tromsogfinnmark/kirkenes-if-og-norild-il-ma-reise-100-mil-for-a-spill-hjemmekamp-i-fotball-nm-1.16338078
- Metric citizin here, nobody uses "miles" here. We just go with the metric system:
  1000 metres = 1 kilometre
  We use the wording from your example "i live 22 kilometres from town"
  
  That's fine and I believe that is true for your country or region. Though remember there are other metric countries. E.g. the nordics still stick to it.
  https://sv.wikipedia.org/wiki/Mil
  
  Interesting trivia piece is that in swimming and running the 1500m is sometimes refered to as a "metric mile" because a mile is 1600ish.
- You're half right. There is no "metric mile" at least not officially.
  But the reason ton/tonne worked in both is that a metric ton is 1000kg and an imperial tonne works out at 1016kg which is close enough for damn near everyone who weighs shit by the ton/tonne.
  But then the Americans and Canadians had to create a stupid hybrid and define the "ton" as 2000lbs (About 907kg)
  
  Thanks for the extra information. But we do have metric "miles" in metric countries. Norwegian spelling, for example, is "mil". Icelandic is "mìla" Etymology is from the imperial mile, again from latin.
  Example from official national dicitonary: https://snl.no/mil
- [This comment has been deleted by an automated system]

Have you ever bought a ton of anything?
Did you put it on the scales and make sure that it was exactly one million grams or go, "yh, that looks like it's about a ton".?
That's why the term ton is popular, the term megagram only really makes sense when you need your "ton" to be precisely one million grams.
- I do not think this is a good take. I buy kilograms of sugar, wheat, I measure my body weight in kilograms and I do not need these measurements to be accurate to one thousandths.
  And yeah, I have bought a ton of something, coal.
  It's a ton (or metric tonne, fine) because people are just used to it, I wouldn't have a problem if everybody started using megagrams, but most people wouldn't even know what it means, especially elderly or people raised with SI but not "getting" SI ("centigrams? do you mean centimeters?").
  It's just a well known alias, nothing else.
- Honestly I don't know what a ton looks like. I've bought stuff like gravel and even the guy selling it had no idea. I asked for half a ton which is the legal limit on my trailer and because the skid-loader didn't have a scale in the grapple he said "I'm just gonna eyeball it". Then on the scale where they do the payment it showed 2 ton, so I had to manually shovel 1.5 ton of gravel off.
  Sure I can visualise a ton of water because it's such a nice unit, but everything else makes no sense. Cubic metres is a much better measurement to visualise.
- Beg to differ. That's kind of an imperial measurement system way of thinking about units. But there's probably some truth to it.
- No. Tolerance is tolerance no matter what the unit is. There is implied tolerance but that's also the same for "one A" and "one B" no matter what A and B are.
  
  If you bought a ton of coal and the tolerance was ±5Kg who's scales are you using when it gets delivered to your house?
  Or are you looking at size of the bag and thinking, yep, looks like a ton.
- My local water services sells it by the ton.

Personally I think it’s irritating to name units with millions and billions in the names.
Imagine everything was built up from microns and we had to say “mega micron” for milimeter. And centi-mega-micron for centimeter and mega-mega-micron for meters. It gets silly and your unit names become formulas instead of highly memorable and intuitive concepts.
Once per order of magnitude you should just re-root the units with more unique names. Keep the conversions metric and clean but give “ton” and “gram” their own names because they live in different order of magnitude scales.

Never heard anyone use megameters either. They either stay on kilometer, or switch to miles. And miles mean different things from one place to the next.
- Who switches to miles if they initially use km? They're the same order of magnitude.
  
  Scandinavians do, 1 scandinavian mile = 10 km.
- Huh? Why would you switch to miles from kilometers?
  And IMHO megameters aren't used that often because there is rarely anything useful to measure with it. Using a different unit makes you lose your sense of scale (e.g. the earth has a radius of ~7000km, not 7Mm) and for astronomy megameters aren't big enough most of the time (and you might as well use lightseconds/years because gigameters give no real intuition of scale).
- Megameters are somewhat common in astronomy, for example when describing low orbital hights.
  
  Really? I would have though that they would use the scientific notation in meters, so that the numbers are explicitly clear.
- Megameter is a real thing though, it's 1,000 km or 1,000,000 meters
- Never heard anyone use megameters either.
  I've used it in one specific situation - Physics classes in my freshman Chemistry uni year. The same professor would also use megagrams for weight.
  It was mostly so the students got a bit more comfortable converting units back and forth, specially past the 10³~10⁻³ range.
  
  Weird, I've never used anything other than unit*10^n on physics. it's just simpler to operate. 1e3m is 1km, 1e6g a megagram. When working on science, I much prefer the scientific notation.
- Kilo translates to thousand. Mega to a million. So in you example, kilometer fits perfectly. Megameter would be a million meters, or a thousand kilometers which is annoying to say on the scale we humans use on a day to day basis. And if it comes to space, megameters are way too little.

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