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.
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.
Megaparsec, kilojoules, kilo electron volt,… are all very common.
Then on the other hand, giga solar masses is never used.
It looks a bit less cluttered, compare e.g. “40.0 Mm” “40.0 x 10⁶ m” or “4.00 x 10⁷ m”. Plus I think that he took into account that he wasn’t lecturing future physicists but future chemists - in Chemistry you rely on those prefixes all the time, and for most stuff you won’t be changing the order of magnitude too much. (Major exception, pK-whatever)
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.
Never seen that for a distance, interesting thought.
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).
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.
Who switches to miles if they initially use km? They’re the same order of magnitude.
Scandinavians do, 1 scandinavian mile = 10 km.
Only in Sweden and Norway.
Denmark used a different mile and it was just as magnificent as our infamous superior number system.
One Danish mile was 12000 alen, where one alen was 2 feet. However the foot was slightly shorter than the English foot.
In total the Danish mile was 7532.48 metres.
Most places aren’t that far away in Denmark, so another common measurement was the fjerdingvej, which was a quarter mile.
Famous scientist Ole Römer made the suggestion to the king to measure all main roads in the period 1691-1698 using this standard. If you walk on old roads, you might find the old milestones placed at the quarter miles. To differentiate the quarter miles from actual miles, they’d have 1-3 holes on the surface.
The whole thing was redone numerous times since then using different scales, where some stones were moved around so it’s completely useless today, but it always makes me happy when I find one.
There are about a million reasons.
The official unit name is megagram. Ton is just used much more commonly.
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.
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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
I order a megagram of sodium chloride and you bring me 1.000001 tons?!?! REEEE3EEEEEEEEE!!!
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?
Try it, count grains of sand in your head whilst you picture them. Unless you’re a savant, it probably starts getting a little blurry around the teens, maybe a bit higher. You can use tricks like imagining a grid of ten by ten to picture a hundred etc, but it’ll still be rather blurry. Picturing a million of something is literally impossible, human minds aren’t designed for that.
If you wanted some sand to line your new brick driveway, would you ask the builders merchant for a x tonnes of sand or a x million grains of sand? It’s the same difference.
When I imagine 1km I don’t imagine 1000 individual meters in my head, I imagine 1km
The point is that you can easily estimate a meter.
Look to the horizon and estimate a kilometre and I’ll bet that your error is significant by comparison to your estimate of a meter.
There is a big difference between imagining/understanding a concept and judging it accurately in the real world.
By this logic, a millianything is also completely unimaginable, because you can’t count to less than one. BS.
That’s the point, millis and megas make sense for things that aren’t tangible in real life. That’s exactly why we use tons and not megagrams.
They literally are the same thing. Why would you imagine them differently?
I’ve had this question quite a few times so I think that maybe I haven’t phrased my point of view so well.
What I’m trying to say is that a million of anything is something the mind can’t comprehend. You can understand the idea of it, but you can’t mentally picture it.
It makes sense to say “my car weighs about 2 tons”, because you can compare that to a couple of ton bags of sand or two IBCs of water.
It doesn’t really make sense to say “my car weighs 2megagrams”, because not only will it not be be precisely 2,000,000 grams, but because no one can picture two million of anything.
Despite the terms meaning the same thing, the mental imagery is totally different and it makes sense to use a unit that makes the description tangible in the real world.
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 used scientific notation or commas (or periods, depending on region) to format those numbers for human consumption, that would also make it easier.
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.
Well I guess an IBC is a bit of an exception if it really does contain 1 kl, although there are also 0.8 and 1,2 kl containers. If you prefer to think of those in terms of cubic meters, then that’s perfectly fine.
It’s just that when you’re buying a reactor, comparing two ponds or reading about annual and monthly production of different companies you bump into these crazy numbers with mostly zeroes. That’s not convenient at all. Even though it could look cool, you don’t see computer people talking about SSDs in terms of individual bytes. You know, prefixes exist too, so why not use them.
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.
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.
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.)
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).
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
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.
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.
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.
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’.
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.)
The good thing: All of them are correct. The SI system actually does not care if you throw around extra zeros, so 1000t is fine. It is actually better to stay in the same SI prefix and just use larger numbers to make list entries easier comparable. Just imagine some ship shop would list it’s smaller offers in Mg and then switch to Gg for larger ships.
Hmm, halfway…
If you take the context away: When you learn that in school, it’s pointed out as a mistake if you write 10 000m. You should have converted that into 10km to get a perfect score.
But there are certainly contexts where it makes sense to stay with one prefix. For example if you write things into a table. Or when your number is basis for a calculation that surely ends you up in the next bigger or smaller realm of numbers.
I’m not sure if it’s necessarily the case for comparing stuff… It’s kind of rare that you have things that are a factor of 10000 or a million apart, so it’s kind of difficult for me to find examples. But I have capacitors that are 470uF or 22pF and resistors that are 220 Ohm or a Mega-Ohm or 150kOhm. They’re all wired into one circuit. I know how to handle that and switch between all of them. So people do switch and that’s kind of the point of having those prefixes. If I type things like that into my calculator, I use scientific notation and after the calculation I use the special key to find me the closest power of ten. I forgot the name of that key. ‘E’ or ‘ENG’. It makes it very easy, you just type in 470e-6 or 22e-9 and it figures it out for you, no matter how convoluted. You need to remember your powers of ten, but you already do that for at least half of them. I think most people know how many zeros are in a million or a thousand.
On the other hand, if i say I’m dividing the road into sections of 100m, im not going to say I’m dividing 2km into 100m sections, but 2000m.
The ‘offerings’ example is good. Because for example internet providers are all over the place. I’ve had a 16000 dsl line, 16Mbit is the same, and nowadays there is anything between 50 to 1000Mbit/s and some advertise it as 1000Mbit, some as a Gigabit line. But they want to sell stuff, not do maths correctly…
If you take the context away: When you learn that in school, it’s pointed out as a mistake if you write 10 000m. You should have converted that into 10km to get a perfect score.
Only if this was explicitly demanded. If the teacher doesn’t, and then claim 10000m is “wrong”, the teacher is wrong.
I think I had a strict maths teacher. But they told us upfront how to convert units and how to do the rounding. So there were no ambiguities.
But I’ve also come to the conclusion that humans can handle numbers up to the ten or hundred thousands as well. We mostly do that instead of converting past kilo. And even textbooks say the sun is on average 150 million kilometers away.
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.
Actually since 2019 the Celsius is defined directly based off of the Kelvin by the SI
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.
Why do we measure fuel consumption in l/100km and not in μm²?
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”
Interesting trivia piece is that in swimming and running the 1500m is sometimes refered to as a “metric mile” because a mile is 1600ish.
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.
That’s not a mile.
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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
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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.
I’ve never heard of gigameter or gigalitre
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.
More-common terms in any language tend to be shorter or at least less standard/more irregular.
I brought a shit ton of tacos. Or I have supplied us with a faecal megagram of tacos. You be the judge.
An imperial shit ton or a metric shit ton?
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.
i do see Mg instead of t in publications sometimes
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.
