The metric system: Make your case for it and why we should switch to it. (As if we haven't already)

Totally irrelevant where I live, where 0C is just about the coldest day of the year, and 30C is the hottest. 0F and 100F are unknown temperatures.

But that’s “out here”. Where I live (Boston) we get days below zero F nearly every winter. In the northern plains they get much colder weather on a regular basis. Temps usually hit -20 F each winter. If you go to the mountains here in the northeast you get temps well below 0 F commonly, at the trailheads. I’ve started many mornings in the negative digits.

And that doesn’t even factor wind chill into the conversation.

Don’t forget the quarts and half-pints. But yes, despite being labeled and bottled in metric, the common vernacular for liquor has stayed the same. We don’t change unless necessary, the 2 liter soda bottle being the rock hard, almost unexplainable exception.

This demonstrates that it is difficult or impossible to satisfy everyone at the same time. F does not avoid negative values, plus one could always point out that °C are “better” in this regard because they only ever require two digits, not three (world records are -89 to +54).

Most advocacy I see in these types of threads are in jest, and those who appear serious tend to:

  1. overstate the value of having a decimalized international standard of measurement easily convertable with other universal physical and chemical properties of energy and matter; or
  2. be so out-of-touch as to be unable to adjust with the slow encroachment of the one true universal SI that will eventually overtake all weak Customary units and standards that they have/will have ever known and finally relagate them to the trash heap of history… where they belong.

10.75m = 1075cm = 0.01075km
8.43yards = ### feet/in? or ### mi ?

Yes, please do mind your pints and quarts… for we shall be minding our litres and and half litres!

That’s not my experience. It doesn’t matter if it is dry or liquid. The criterion is whether the ingredient is something that can be poured.

Yes, sugar and flour will be measured in cups and spoons because it is so much easier. And spices will certainly be in spoons, because I have a measuring spoon marked “1/2 teaspoon”, whereas I’m never going to trust a household scale to tell me that I have 2 grams of chili powder.

But things that can’t be poured are always weighed. How else are you going to measure an amount of meat?

I have a battery operated scale that accurately weighs grams. I use it in the kitchen as well as in the man cave.

So do I, and I have no problem using it for large amounts. But for tiny amounts the chance of rounding error is just too high. My only point was that for a 2-gram measurement, a large error will not register on the scale’s output, and that a spoon is much better for such tasks.

OK, I see your point. Thing is for most cooking where I’m adding tsp or Tb of whatever, I just measure into my hand, no spoons/scales needed. (I don’t bake much)

I have checked my accuracy, putting what I think is a tsp of garlic powder onto a paper plate, then pouring it into a measuring spoon. Pretty accurate.

For most spices, those are just suggestions. I don’t measure accurately and use my cooking knowledge to add the appropriate amount which is typically at least double what it calls for. Not as true for smaller measured items like baking powder. We also use a scale for baking, in particular our bread making and starter feeding.

And yes, the US should go all in on metric. I got an engineering degree back in the late 80s/early 90s and we had to do problems in both systems. I loved the metric problems.

First: I dispute that flour can be poured. You can sorta dump it in a large bowl, but good luck getting any accuracy out of that without a scale.

Second: sure, meat is roughly by weight but it’s also by “unit” (12 chicken wings, etc.). The weight is just for a rough serving size. If a recipe calls for 2 lbs of meat then you grab a 2.13 lb package from the store. No one weighs it at home.

Mostly, exact amounts are irrelevant for anything outside of baking. Which can be seen by the fact that ingredients are quantized to just a few values. No one specifies 4/5 teaspoon of chili powder; they just round up. But in baking, the quantities of a few key ingredients really do matter a lot and doing those by weight makes a difference.

Why do you need to measure 2 grams of Chili in your man-cave?


What happens in the man-cave, stays in the man-cave.

Just as an aside, if you are concerned about weighing accuracy with a powder, a good technique would be to weigh (say) 5 times the amount, then subdivide the pile of powder into 5 equal piles of roughly equal size by visual inspection. It may be easier to ensure that the subdivided piles are equal in size if you put the powder on a smooth surface such as a mirror and use a razor blade to form the piles into thin elongated piles of equal length.

To address this entirely separate matter, I can’t possibly imagine.

SI has four main advantages over the American system:

The most-often cited, but least important, is that different units for the same quantity in metric have conversion factors that are powers of 10. This is convenient, sure, but hardly necessary.

The second-least important benefit is that it’s the system used by the majority of the world. Things work better when everyone uses the same units, and it would be easier for us to change to match all of them than for them to change to match all of us. Though admittedly, this isn’t anything inherent to SI; it’s a quirk of history (albeit one driven by the other reasons).

The third benefit of SI is that it’s what’s called a coherent system. The base units for various quantities are derived by multiplying or dividing base units for other quantities. If you take the SI unit of force times the SI unit of distance and divide by the SI unit of time, you’ll get an answer in the SI unit of power. Tell me, how many foot-pounds per second are there in a horsepower? I don’t know, but car people need to know, and they shouldn’t need to know.

The fourth benefit is that it’s a standard. You can’t compare the meter to the foot, or the liter to the pint, because there is no the foot, or the pint. Distance measurements can be statute or surveyor’s (or, in the case of the mile, nautical). Volume units can be American or Imperial. Weights can be Troy or Avoirdupois. I’ve seen old rules that had twelve different inches marked on them, for different countries (thankfully, that’s nearly obsolete now, because most of those countries have abandoned their inches in favor of metric). And I have a recipe that I can’t make right, because I got it in Ireland, and I don’t know if the units are imperial, for a British Isles audience, American, for the tourist trade, or a mix, because the author tried for one or the other but knew about some but not all of the differences. If the recipe had instead been in liters and grams, I’d have no such problem, because a liter is always a liter and a gram is always a gram, for everyone.

Heh. I like to weigh my dispensary purchases, not because I think the growers might short me, but because it feels so good getting an extra tenth of a gram.

I’ve noticed that 12 ounce cans of Coke now have their energy content printed in both kilocalories and kilojoules. Are kilojoules typically used in countries using the metric system?

Dual labelling appears to be permitted, due to pressure from Britain and the United States; see
French Coca-Cola label, 2008:

When in Australia about twenty-some years ago, I was surprised to see “low-joule cola.” Diet Coke was still Diet Coke, but instead of “low-calorie” on the can, it said, “low-joule.”

Many years ago, a colleague of mine figured out how much power it took to accomplish each milestone on his annual performance plan.

It’s about a milliwatt, I think.

Agreement came astonishingly late, but predated abandonment by many years.