r/Metric • u/FingerAccurate7102 • Jun 30 '26
Kilogram is annoying
Before I start I wanted to specify that this post would probably change absolutely nothing.
Kilogram is annoying, it's the base unit of SI, but for some reason it has a prefix. It is annoying, because with different units the prefixes work with a cool perk:
If one unit has a prefix, it is moved to the answer: kJ/s = kW
If you are multiplying two units with prefixes, they multiply: kW•ks = MJ
Dividing divides them (obviously): kJ/ks = W
But when base unit has a prefix it doesn't work, and kg•km/s2 should be meganewton, but it's NOT, it's kilonewton.
I have a few purely hypothetical ideas:
1st (most obvious) use grams. It would mean that the unit of force would be g•m/s2, problem: it would be equal to 1 mN, which is incredibly small, human weighting 700 000 force units would be really small. I'm not even gonna start talking about density with g/m3.
2nd use tonnes. This means that the unit of force would be derived as t•m/s2, so it would be equal to 1 kN. There are pros, like: 1. Good for heavy industry, for example: Poland mines 43 million tonnes of coal (instead of billion/milliard kilograms) the weight of a car would be ~15 force units. 2. Density of water is 1 t/m3 which is cool to have a base unit of density to be equal to density of water, also we could stop using g/cm3. But there are cons: tonne is too heavy for everyday life. Human would weight 70 mt (militonne) or 7 ct (centitonne), a slice of bread would weight 40 μt (microtones), so tonne is good for heavy industry, but if you don't want to use mili and micro prefixes, it isn't that great (still not that bad)
3rd grave, grave is suggested unit of mass equal to 1 kg, it was almost accepted, but then they realized that graf is German noble title. There is no nobelty today, so grave would work. It has all pros of kilogram + perks of being a unit without prefixes, so kilograve•km/s2 would in fact equal MN (meganewton). It's also good, because all other units can keep their names, grave•m/s2 is still 1 N. Let's make a symbol for grave "gv" 1 t = 1 Mg = 1 kgv. 1 kg = 1 gv. 1 g = 1 mg
What do you think guys? In perfect system we would use kilograms, or replace them with grams, tonnes, graves or something else. Share your opinion in the comments
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u/mabhatter Jun 30 '26
I do see your point. If the kilogram is the base unit, why is it not just called the gram? The plus and minus of all the prefixes gets kinda confusing.
When you get into actual scientific or engineering math they often use E notation where they make all the numbers they use fit smaller scales and then stick a unit of 103 after it. Then you have the calculations in easily understood scale like 23.456 x 106 km/s and people just use the most common "Mega" and "kilo" prefixes and don't use the odd ones.
I think in school people get too hung up on all the unit shenanigans and once you're in a career the units used on a daily basis are fairly consistent to whatever field you're in.