• rufus@discuss.tchncs.de
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    1 year ago

    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.

    • supercriticalcheese@feddit.it
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      1 year ago

      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.

      • rufus@discuss.tchncs.de
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        1 year ago

        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.)

        • supercriticalcheese@feddit.it
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          1 year ago

          The official definition of a 1,000 kg is Mg but it’s not very frequently used in practice. Mostly because use of metric tonnes was already diffused

          Keep in mind that there is more than just SI units used in Europe in the past. For example if you read through an old thermodynamics textbook in Italian it is likely to use a lot calories and often the CGS system (centimeter grams second and calories).

          • rufus@discuss.tchncs.de
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            1 year ago

            Sure. I’ve grown up with that stuff, too. And we also get our weather forecast in celsius each day… You don’t even have to open an old textbook for that.

          • Ziggurat@sh.itjust.works
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            1 year ago

            CGS system (centimeter grams second and calories).

            For the pleasure to be pedantic, the proper CGS energy unit is the erg, not calorie.

            But indeed, even in France, home of the metric, you’ll find people using some customary unit (Calories, or pounds) and even some US units like inches for computer-screen and feet for powered airplanes altitude, and then a shit ton of approximation

        • Vlyn@lemmy.zip
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          1 year ago

          But it literally is a kiloton? Mostly getting used for explosives if you talk about it, but it’s used:

          kiloton /ˈkɪlə(ʊ)tʌn/
          noun: kiloton; plural noun: kilotons; noun: kilotonne; plural noun: kilotonnes
          a unit of explosive power equivalent to 1,000 tons of TNT.

          The reason megagram isn’t used much is because it would be shortened to mg. Which is usually milligram. Sure, you could go the “Mg” route compared to “mg”, but that sucks. So “t” for ton works well. It’s just another name though, it doesn’t matter.

          • rufus@discuss.tchncs.de
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            1 year ago

            Yeah, I know. But you have the problem with the letter ‘m’ everytime. You just have to pay attention and write it correctly. And there is also ‘micro-’ in addition to the ‘milli’ and ‘mega’ you mentioned. However, most of the time it’s unlikely you’re off by a factor of 1 billion and won’t notice. Just do it right: 'µ, ‘m’, ‘M’. (Also there are other letters like the ‘p’. But there’s an even bigger difference between those two.)

            If you listen to my school teacher, you’re not supposed to use SI prefixes with other things. I think that’s not true but would apply to the ‘kiloton’. People wouldn’t like me talking about a ‘kilo-foot’ or ‘milli-yard’… I’ve had 3 deca-spoons of soup or there were 2.5 kilo-people at the concert… It took me 15 milli-days to finish the task… What? 1k8 euros for a graphics card?

            I don’t think there is a clear line. The SI unit system is good. But we still have plenty things that aren’t a certain way because of history and ‘reasons’.

          • supercriticalcheese@feddit.it
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            1 year ago

            I think it’s mostly down to the fact the units could be mixed when written down.

            Mg and mg should not create confusion in theory the standard milion prefix in metric is a capital M.

    • mommykink@lemmy.world
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      1 year ago

      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

      • rufus@discuss.tchncs.de
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        1 year ago

        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.

        • force@lemmy.world
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          9 months ago

          Actually since 2019 the Celsius is defined directly based off of the Kelvin by the SI

    • Provoked Gamer@lemmy.ca
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      1 year ago

      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.