[mulmen]

> 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.

[usrbinbash]

> 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.

[mulmen]

> 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.

[usrbinbash]

> 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

[mulmen]

> 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?

For the same reason the metric (literally international standard) system was created. There were many similar systems in use. US Customary was a standard system for the whole country. The problem being solved was different standards for the units. US Customary solves that problem. Only the standard definition of the unit changed. This has been done within the metric system as well, even very recently.

> > Nobody is doing this.

> Yes, people are doing such calculations all the time.

What I mean is that specific conversion with hundredweights.

I’m unclear why anyone would do any of your example calculations in their head. They’re all so important that it would be done precisely on paper or electronically. All a worker pouring a foundation meeds to know is the desired dimensions. All the truck driver needs to know is the quantity ordered. Nobody is actually converting precise quantities of concrete or solar panels in their heads.

[Aloha]

Not to mention, you can do those calculations in your head if you're familiar enough with the subject matter, concrete guys do it all the time.

[Aloha]

Yes hundredweight is an official measurement, but it's not a widely used one (I think it might be used in the sale of nails only?) - which is the parents point. We'd just calculate it in pounds or fractional tons.

You act as if these calculations are simply impossible in customary units, they're not and we do them all the time.

To go on from this, we've converted everything that meaningfully effects our external competitiveness, as I said in a parallel comment I dont think our competitiveness would be helped or harmed if meat was sold in kilograms vs lbs or if we have temperature on the weather forecast in Celsius.

[saalweachter]

Hundredweight show up in agricultural settings -- you'll see the price of pork being $123/hundredweight, instead of $1.23/lb. I assume this is because the price of meats used to be pennies per pound, and people wanted the numbers to be bigger, $12.50/hundredweight instead of $0.125/lb.

[usrbinbash]

> You act as if these calculations are simply impossible in customary units, they're not and we do them all the time.

No I don't. I said they are more difficult than they have to be, and for no good reason.

> I dont think our competitiveness would be helped or harmed if meat was sold in kilograms vs lbs

https://gizmodo.com/five-massive-screw-ups-that-wouldnt-have...

Maybe not, but it would probably have helped in not having a 125 million dollar space probe go up in flames.

[mulmen]

125 million dollars is precisely nothing in the scheme of interplanetary exploration and we already learned our lesson. I would expect someone so obsessed with radix 10 as yourself to understand orders of magnitude.

In the places it matters the US already uses the metric system. This has been true for more time than Germany has used the metric system.

Since the time the metric system was created a world war was fought, centered around a misguided sense of supremacy. The people with a sense if moderation and the ability to compromise in the face of real constraints won the war. The adherents to strict philosophy were destroyed.

The Mars Climate Orbiter crashed because of a miscommunication. We could have done it all in IS Customary units. Nobody did any calculations in their head. This is a hard task. We learned from that, as we always do. The US has still led the largest presence on Mars. We know what we are doing.

[saalweachter]

> How much rain did fall on Hamburg in 2022 given a city size in square kilometers, and an average fall of cm/day.

Oh, now you're in US customary unit territory.

Let me introduce you to the acre-foot.

The acre-foot is the unit of measure for reservoirs. For instance, the Ashokan reservoir is 8300 acres with an average depth of 46 feet. Its volume is 381,800 acre-feet.

If an area 10,000 acres received 3 inches of rain, you need 2500 acre-feet of reservoir to put the outflow in.

How big do you need to make your 2500 acre-foot reservoir? Well, if you're working with 100 acres, you make it 25 feet deep.

[johnwalkr]

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.