Can anyone with a deeper understanding of the history of the metric system explain why a gram is the base unit of weight, and a litre the base unit of volume?
I thought the foundation of the system was that a kilogram is the weight of a litre of water. But then why not name them 1 thing = 1 thing rather than 1000x a thing = 1 thing.
And yes I’ve had four cups of coffee and no sleep today.
A gram is not the base unit, it started with one meter (hence, metric).
Kilo means thousand in Latin, so 1000 meters became one kilometer (aka, one thousand meters), and when they need smaller units, they took to Latin again, simply because the language was en vogue for science:
Deca (ten): Decimeter (dm, nowadays hardly used, but it exists) = 0.1m
Centum (hundred): Centimeter (cm) = 0.01m
Mille (thousand): milimiter (mm) 0.001m
Weights were then adopted from the dimensions based on practicality, i.e. one liter was a common enough volume that people could use it in a household, and it’s defined by 1dm height x 1dm length x 1dm width. Or 10cm10cm10cm (same thing, but the base notation was units of one).
The only use of the decimetre I’ve seen in real life, is that the standard school rulers, being 20 cm long are commonly called “double décimètres” (in France). Maybe other places use them more.
Sub-units are a bit like regionalisms, France likes cl for liquids, many places like adding zeroes and using ml, maybe some use dl…
That’s an interesting question that I’d never thought about before.
I asked chatGPT, which predictably bullshitted me and said they’d decided grams made more sense than kilograms for scientific lab work.
But then I searched and found this from the user tomalator on Reddit:
“When the French were developing the metric system, they suggested the unit be called a grave (pronounced grav) being the mass of 1L of water (1000 cm3)
The French at this time being in the middle of a revolution against the rich notice that it sounded a lot like the word Graf, being a word for Duke or Earl, and they wanted to avoid affiliating with the nobility, so they changed the measurement to be the mass of 1mL of water (1 cm3) and called it the gramme
They then noticed that it was inconvenient to use a mass unit so small, so they changed back to the 1L of water definition, but kept the name gramme for the base, and threw out the word grave in favor of the kilogramme.
And that’s why the kilogram is the base SI unit and not the gram. I had the exact same question when I learned the SI unites.”
Can anyone with a deeper understanding of the history of the metric system explain why a gram is the base unit of weight, and a litre the base unit of volume?
I thought the foundation of the system was that a kilogram is the weight of a litre of water. But then why not name them 1 thing = 1 thing rather than 1000x a thing = 1 thing.
And yes I’ve had four cups of coffee and no sleep today.
A gram is not the base unit, it started with one meter (hence, metric).
Kilo means thousand in Latin, so 1000 meters became one kilometer (aka, one thousand meters), and when they need smaller units, they took to Latin again, simply because the language was en vogue for science:
Deca (ten): Decimeter (dm, nowadays hardly used, but it exists) = 0.1m
Centum (hundred): Centimeter (cm) = 0.01m
Mille (thousand): milimiter (mm) 0.001m
Weights were then adopted from the dimensions based on practicality, i.e. one liter was a common enough volume that people could use it in a household, and it’s defined by 1dm height x 1dm length x 1dm width. Or 10cm10cm10cm (same thing, but the base notation was units of one).
Just FYI - Lemmy uses Markdown for formatting. In Markdown, if you surround some text in asterisks, it italicises whatever’s in between.
So if you write:
*this is italicised*, you get this:this is italicised
To write
10cm*10cm*10cmyou have three options:Use in-line code (what I did twice here) - surround the text in backticks (usually the ones on the left of the number 1 on the keyboard).
Use “x” instead of “*”.
“Escape” the asterisks by adding “\” before them. You’d write it like this:
10cm\*10cm\*10cm, and you’d get: 10cm*10cm*10cm.The big prefixes (kilo, mega, etc) are actually Greek and the small ones Latin.
The only use of the decimetre I’ve seen in real life, is that the standard school rulers, being 20 cm long are commonly called “double décimètres” (in France). Maybe other places use them more.
Sub-units are a bit like regionalisms, France likes cl for liquids, many places like adding zeroes and using ml, maybe some use dl…
That’s an interesting question that I’d never thought about before.
I asked chatGPT, which predictably bullshitted me and said they’d decided grams made more sense than kilograms for scientific lab work.
But then I searched and found this from the user tomalator on Reddit:
“When the French were developing the metric system, they suggested the unit be called a grave (pronounced grav) being the mass of 1L of water (1000 cm3)
The French at this time being in the middle of a revolution against the rich notice that it sounded a lot like the word Graf, being a word for Duke or Earl, and they wanted to avoid affiliating with the nobility, so they changed the measurement to be the mass of 1mL of water (1 cm3) and called it the gramme
They then noticed that it was inconvenient to use a mass unit so small, so they changed back to the 1L of water definition, but kept the name gramme for the base, and threw out the word grave in favor of the kilogramme.
And that’s why the kilogram is the base SI unit and not the gram. I had the exact same question when I learned the SI unites.”
First they defined the meter and then one litre was defined as one dm^3.
4 cups, you have had a quart of coffee, sir ;)
I believe a gram is the weight of a cubic centimeter of water, and a liter is 100 cubic centimeters of water.
The meters are kind of out there though that is something to do with like the meridian and distance between lattitudes or something I forget.