Comment by mulmen
3 years ago
> It's not a question whether they are arbitrary, it's a question if they are technically consistent within themselves.
It's important to note that the US does not and has never used the "Imperial System" which didn't even exist before 1826 which is post-revolutionary war. US Customary units evolved around the same time as the Metric system and used names from the Dutch and English systems for historical reasons. The motivation being global compatibility, not internal consistency. The US was an original signatory of the treaty of the Meter. The British Empire (and thus, Canada) was not.
Personally I think internal consistency is overrated. It's nice to have but really reads like marketing wank. What matters to people doing work is if they can do their jobs. In those contexts change is far more costly than conversion to a new system. Tooling will already be built to deal with appropriate units.
One example of this is in metalworking machines. Those tend to last for decades and entire companies have built portfolios of designs and programs in thousandths (base 10 for those playing along at home) of an inch. It is unlikely that converting all those designs to microns would justify the cost, so we don't.
Almost all food packaging in the US has both systems printed on it but I am unclear how my dinner will taste better if I measure the ingredients in SI units. It just doesn't matter in that context.
> The motivation being global compatibility, not internal consistency.
All the more reason to officially switch to metric. Because as of right now, only 3 countries in the world (US, Liberia and Myanmar) officially use imperial units, while the rest of the world uses the metric system.
> The US was an original signatory of the treaty of the Meter.
So? If I have a gymcard and don't go to the gym, it's not doing me any good.
> It's nice to have but really reads like marketing wank. What matters to people doing work is if they can do their jobs.
Indeed it does. That's why science and engineering are using the metric system. Including NASA btw. Being able to convert measurements easily, and have them correlate with our most common, radix 10, numerical system, is not "marketing wank", it's a built-in advantage.
If I want to figure out what mass of water falls on an area in the metric system, I can do the calculation in my head. If I have to figure out hundredweights per acre, given that X inches of rain fell, I'm gonna need a calculator, a conversion table, and social context to know which kind of "hundredweight" I'm supposed to use.
Oh btw. people "do work" in all these other countries. And guess how they measure things when doing that? Exactly: In meters and kilograms.
> Because as of right now, only 3 countries in the world (US, Liberia and Myanmar) officially use imperial units
This is not true. The US has never used the Imperial system, we use the US Customary system, which has been based on the metric system since 1893.
> If I have to figure out hundredweights per acre, given that X inches of rain fell, I'm gonna need a calculator, a conversion table, and social context to know which kind of "hundredweight" I'm supposed to use.
Nobody is doing this.
> and social context to know which kind of "hundredweight" I'm supposed to use.
Since as you say everyone else uses the Metric system it should be pretty easy to figure out. As an American I have never even heard of a hundredweight, not sure why you are so fixated on this unit.
> This is not true. The US has never used the Imperial system, we use the US Customary system
So how is using yet another different system defining arbitrary measurements that cannot be easily converted, do not directly correspond with the radix 10 numerical system, and are also not widely used make things better?
> Nobody is doing this.
Yes, people are doing such calculations all the time. How many concrete transports will a construction company need to make a foundation, if the depth is 2.2 m², the size is 97.2 m² and the specific weigth is 2.5 tons per m³?
How much rain did fall on Hamburg in 2022 given a city size in square kilometers, and an average fall of cm/day.
What kind of energy output can a solar farm provide given a conversion rate, panel efficiency, panel angle, and land size? Easy to do if all is in SI.
> As an American I have never even heard of a hundredweight
It's an official unit of the us customary system:
https://en.wikipedia.org/wiki/Hundredweight
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Machinists have no problem working with designs in SI units on an inch-based machine. Lots of American companies use metric in designs and machine shops have to deal with it, although shops are moving to metric more and more. When they do this they keep and use their old machines with no problem although it’s an annoyance. Conversely metric machine shops can make inch-sized parts with no problems. Lots of material stock is inch-sized in the US, so even when you design in metric you have to consider this. But over time there is more metric stock available in the US, and for things like precision shafts there’s no cost difference anymore.
Regardless of everyday usage, in mechanical engineering/metalworking, the switch to metric has already been happening slowly since the 70s. Old machines and designs can stay in inches but most industries are already moving to metric unless there’s a compelling reason not to. You can see in Canada what things have stayed in inches because of regulations and material availability. House framing and steel weldments come to mind.