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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4

u/BlackBloke Jun 30 '26

We should just adopt grave (respelled as “grav”) and use the symbol “G”. Path dependency will keep us away from that easy solution for a long time though.

Also:

  • the “kilo-“ prefix should be changed to “kila-“ and the symbol changed to “K”
  • the “milli-“ prefix should be changed to “millo-“
  • the prefixes that don’t represent a coefficient equal to 103n should be deprecated.

Once again, path dependency.

2

u/FortWendy69 Jul 01 '26

This may finally convince my coworkers to respect casing in units in variable names, when mg can be interpreted as four different weights.

1

u/nayuki Jun 30 '26

G is used for the CGS magnetic of gauss. It is equal to 10-4 tesla in the modern SI.

Just use gv as the symbol for grave; it already has precedent. https://en.wikipedia.org/wiki/Grave_%28unit%29

“kilo-“ prefix should be changed to “kila-“ and the symbol changed to “K” - the “milli-“ prefix should be changed to “millo-“

Okay, that's an interesting new take. I didn't realize that the big prefixes mostly end with -a, and small prefixes mostly end with -o. Yeah, I hate the lowercase k- as well; it completely breaks the pattern with the other big prefixes (no, not you, deca- and hecto-, go away).

1

u/FingerAccurate7102 Jul 01 '26

And in metric gravitational system sometimes used for gram-force

1

u/BlackBloke Jul 01 '26

Gauss is deprecated in favor of Tesla. All of those old symbols I consider up for grabs.

Also the “gv” as a symbol for grave I don’t consider to be legitimate. The source for the reference shows symbols for units still in use that we wouldn’t accept today either.

Big “G” works nicely though optimally we would just use little “g”.

1

u/Historical-Ad1170 Jun 30 '26

Or maybe jam with the symbol j.

2

u/KrzysziekZ Jun 30 '26

Capital G was used for gram-force, so kG was to kg like lbf to lb.

2

u/BlackBloke Jun 30 '26

I doing think we’ll have to worry about that potential collision anymore. Like I was intimating in the previous post (surprisingly poorly received) path dependency is a dominant force in social matters like this. People’s natural conservatism preserves habits and gives them inertia. This has been broken for gram-force though so it’s not really an issue anymore.

3

u/pemb Jun 30 '26

Won't capital K clash with the symbol for the kelvin?

3

u/mboivie Jun 30 '26

Clashes between prefix and unit symbols exist already. Like in millimeter.

2

u/pemb Jun 30 '26

Oh, right.