Actually 0°C is only approximately important. water on roads doesn’t usually freeze until the temperature drops lower. And it the roads have been salted, quite a bit lower.
And 98.6°F is not incidentally 37°C. Normal body temperature ranges from about 97 to 99. It just so happens that 37°C is the only integer within that range so it was picked as the standard. For some reason, perhaps to be consistent, that was translated as if it were an exact number to 98.6°F. It probably would have done better to just say normal was 98°F in the US, but again it might have made cross country comparisons for research harder. But 98°F is closer to average than 37°C. I believe current consensus on average is 98.2°F.
This misses the point. Nobody has said that it never, ever, ever in the history of civilization has it gotten colder than 0 or hotter than 100. It is a reasonable scale that sets a general 0-100 range of the experiences of human temperature.
For most of the world, when it gets below 0F, it is really damned cold, unusually cold in most areas. If it gets above 100F, it is really damn hot, unusually hot in most areas
As it gets to -40F in some areas and 120F in others, we could recalibrate the scale, but then that would make it less useful for most people.
The difference is that nobody is arguing that other countries should switch to F, but the point of these threads is that the US should switch to C when there is no particular reason to do so and from our POV, Fahrenheit is better.
I don’t have anything akin to a comprehensive answer, but I’ll throw out a meaningful anecdote.
The early to mid 1970s was one period, possibly the period in American history, when the momentum seemed to be in favor of switching to metric. We got a lot of “metric system” lessons in math class. And what did those lessons focus on?, you may well ask. Freaking conversion equations! Multiplying numbers provided in feet and inches to get meters and centimeters. Obtaining the quarts, cups, and leftover tablespoons and teaspoons for volumes given in liters and milliliters.
Instead of showing off the elegant easy side of the metric system, it left an entire generation of schoolkids with a negative experience associated with dealing with it. Oh, metric system, that means I have to know that 1/4 cup of water is 59.14705 ml, whoopee, thrills.
If they were serious about getting our loyalties, they should have left conversion equations as an optional appendix and instead given us a leak in the basement, measured in either teaspoon-fractions or milliliters per minute, with available pans in either gallons or liters, and had us figure out whether the biggest available pan would let us leave home for the weekend without having to come to home to an overflowing pan.
I hadn’t brought it up in this thread, but I’m right with you on that being a big advantage of metric over the “customary” standard. But that’s still not even the biggest difference. The biggest disadvantage of the “customary standard” is that it isn’t even standard. When you refer to a pint, do you mean an imperial pint, or an American pint? Is a mile a statute mile, a survey mile, or a nautical mile? Ton: Long or short? How about the pound: Is that Avoirdupois, or Troy? And whichever one you pick, is it a mass or a weight? Heck, the ounce could be a mass, weight, or volume, and depending on the answer to that, could also be either Avoirdupois or Troy, or either imperial or American. Yes, you can usually figure out from context which one is meant… usually. But if I’m buying a 12 oz tub of whipped cream, I most certainly want to know whether that’s a mass or a volume. And it defeats the entire purpose of units if they’re not standard.
When you say the “metric system” do you mean: metric, MKpS, MKS, CGS, MTS, or SI? When most people say ‘Metric System’ they mean SI or Système international d’unités.
When someone from the us uses the term 'customary units" they mean the US customary units which are just as defined as SI or the Imperial Units. The British Imperial measurement system and in the United States customary measures systems names for units are not ambiguous within their usage domains.
As for the difference between fluid ounces and volume ounces, blame the Romans and actually the liter changed multiple times. SI has a process to enforce revisions which is really one of it’s huge benefits IMHO.
Original: 1 cubic decimetre
1904: volume of one kilogram of pure water at 4 °C (39.2 °F) and standard atmospheric pressure.
1964: 1 cubic decimetre
Also note the liter is a Non-SI unit that is acceptable for use with the SI Units.
SI is still the best deal going, but it is anachronistic to take present-day SI consistencies and ignore present-day non SI systems of measure and historical fixes.
Just like you can ignore “pound-force” as a base unit if you are not an Engineer, you can ignore Troy rate if you are not buying and selling precious metals and gemstones. Those carryovers are due to specific industries and are not used to measure metrification of any country in the world.
And before someone asks, if a country was actually using SI units for volume products would be sold based on V = m[sup]3[/sup] which is the coherent derived unit for volume in the SI.
Liter was added to the acceptable list because of the political difficulties in getting users to drop the non-SI unit, just like with the USC and Troy systems. If more voting members of the treaty had used pounds and inches they may have been added too.
Found the name for the original metric unit of dry volume, the stere which was one cubic meter just like the current accepted derived SI unit of volume.
While lacking the name conflict with ounce and fluid ounce, that complexity did exist. There was a conflict with “cubic meters” and differing industry meanings related to woodpiles etc… which caused it to be dropped for the derived unit of volume; yet people continue to use the old, dropped unit for liquid volume or liter.
The metric system has had warts too, there is just a process to have them removed.
The question of which is “better” is no longer relevant because that ship has sailed, and it left the harbor many years ago. The relevant question today is, does the US wish to be virtually the only country in the entire world sticking with an archaic and incoherent system of measure. If so, the obvious conflict with the rest of the world, with all scientific standards of measure, and indeed with many of its own domestic standards, would seem to require a powerful justification, and “we think it’s better” or “we’re just used to it” doesn’t seem nearly adequate.
What? The conversion between incompatible systems of measure is always going to be messy. The point is that the “customary” system of measure is internally messy, whereas the SI system is designed to be both elegantly simple and coherent:
How many meters in a kilometer? 1000
How many centimeters is that? 1000x100
How many cubic centimeters in a liter? 1000
How many grams in a kilogram? 1000
How much does a cc of water weigh? 1 g (at maximum density)
How much does a liter of water weigh? 1 kg
Now try the equivalents in the “better” system of measures!
