I suspect that only a minority of people in metric-using countries -- those with basic chemistry knowledge fresh in their mind -- know that "one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade".
Probably a similar number of Americans know the same facts. And any of them would answer "How much energy does it take to boil a room-temperature gallon of water" in the only sensible way -- look up the conversion of gallons to liters, do the calculation in metric, and convert back from calories to whatever unit you want (BTUs, I guess).
The point is: nobody, including Americans, uses the customary system in chemistry labs. Nobody ever has cause to calculate how many BTUs it takes to boil a gallon of water without reference to the metric system. So the argument is a bit specious.
> I suspect that only a minority of people in metric-using countries -- those with basic chemistry knowledge fresh in their mind -- know that
This is not the case. This part: "one milliliter of water occupies one cubic centimeter, weighs one gram" is known by most people, even kids in primary school. In other words everyone knows that a litre of water weighs one kilogram, and that there are 1000 litres in a square metre. I concede, though, that at least in Italy, which is the country where I was born and raised, most people wouldn't know the next part: "and requires one calorie of energy to heat up by one degree centigrade".
It's common knowledge here; in the UK I was taught it in two classes at school: Science and Cooking.
We are taught to use the scales for measuring ingredients - and thanks to this trick you can weigh water (and milk) and vegetable oil (using 5-10% less) if you don't have a measuring jug.
> I suspect that only a minority of people in metric-using countries -- those with basic chemistry knowledge fresh in their mind -- know that "one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade".
They taught us that in 4th grade in cooking classes. Then they made us remember that in physics and chemistry classes 2 years later.
The point is that this particular concept of metric units is taught really well (repeatedly on many practical examples and then evwn theoretical ones) and so virtually everyone knows and uses it. It's deeply ingrained in cooking books, recipes, etc.
Of course I don't remember a lot of things from the 4th grade. This one stands out.
>I suspect that only a minority of people in metric-using countries -- those with basic chemistry knowledge fresh in their mind -- know that "one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade".
I wouldn’t be so certain about that. I’ve used that to conceptualize volumes and weights ever since I first learned that in school.
Nice point, but it is really the typical elementary school topic "one cubic centimeter of water is one gram, one cubic decimeter is one kilograms, one cubic meter is one THOUSAND!!! kilograms"
Then in highschool it is used for physics and unit of measurements and everyone knows that you can just weight milk and water when you cook with 1kg = 1liter
Normal people don’t do that. They just know that a gallon is a gallon, a meter is a meter, a pound is a pound, etc. People rarely have need to convert between mass and volume. And they don’t weigh their milk or water.
Probably a similar number of Americans know the same facts. And any of them would answer "How much energy does it take to boil a room-temperature gallon of water" in the only sensible way -- look up the conversion of gallons to liters, do the calculation in metric, and convert back from calories to whatever unit you want (BTUs, I guess).
The point is: nobody, including Americans, uses the customary system in chemistry labs. Nobody ever has cause to calculate how many BTUs it takes to boil a gallon of water without reference to the metric system. So the argument is a bit specious.