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It's time for the US to use the metric system

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Re: It's time for the US to use the metric system

#52
post #45

Earlier quoted context omitted.

> (Such that lumber is sold in lengths of 243.82 cm rather than 8 feet.) It's interesting that you pick that example. In many cases, the "measurements" for lumber don't actually correspond to the true dimensions of the product purchased. For example, a "2x4" has dimensions of 1 1⁄2 inches x 3 1⁄2 inches[0], rather than 2 inches by 4 inches. So, at least for the example you give, it's not clear to me that converting t…

It is not nonsensical, 2x4 is the rough sawn size. Edit: Since I can't reply because of HN's helpful 'You're submitting too fast' notice, I will reply here. You can still buy rough sawn for working on existing structures and for aesthetics when exposed.

I don't have primary source info, but from the wiki article I linked, that used to be the case, but is no longer the case. All that matters now is the final cut dimensions.

Re: It's time for the US to use the metric system

#53
Some thoughts on a conversion that I don't generally see brought up:

* From an economic standpoint, the US is a big enough market that it is profitable to make things in weird US units, you have 350M people to sell to, most of whom are pretty well off by world standards. It makes sense to make a line catering to them. If businesses can start making a true or good economic argument it will happen more.

* Tooling that exists in standard units seems to be a bit of a red herring: I dislike having to own wrenches in both standard and metric units - a transition to one set would actually be nice. At a larger scale, i.e. manufacturing, it would make sense to start replacing things with metric on regular maintenance cycles. With very long cycle things just having a label change.

* Paper would be a nightmare for a while - A4 and 8.5x11 are just dissimilar enough for it to be weird, and paper has a very long lifetime, dual storage systems are a pain.

* A lot of very low level infrastructure has built in assumptions about standard measure that would take a long time to convert, and some would never convert. For example, a lot of cities put roads so that $X blocks is a mile. The midwest from the air looks like a quilt - thats because all the fields are partitioned by roads which are (generally speaking) a mile apart. Land ownership for rural areas is by the fraction of a section, and by acres - it's built in to how everything is laid out. These aren't impediments but it does create a weirdness. I navigate the backroads and a lot of parts of cities by knowing how far it is and just counting how far over and how far up i need to go subconsciously, and it is an issue.

* Now is a better time than ever for doing this in terms of accessibility to the public. Everyone has a smartphone - apps to do conversion in lots of intuitive ways can ease people's discomfort.

* Car, motorcycle and other mechanical equipment manufacturers should be the people to start the transition. They can all agree to just stop using standard things for the 20XX line of equipment. Or be legislated to do so. Similarly gas stations can be required to change on $DATE, and car manufacturers can just send everyone stickers to put near the gas-hole of cars to say "your tank is $X litres". I think this would help tons. No dual labeling, just bam - it's in litres now.

* Housing things are another weird infrastructure thing: they last for a very long time. Codes are all in inches -- doors must be 36" wide, switches must be placed at 48" and so on. The sudden appearance of a second width and height for new stuff would be bizarre, or building it at 91.44 and 121.92 cm respectively would also be annoying.

I still think it's a good idea, but some thought needs to go into these weird cases that are surprisingly common before a transition would be acceptable. But like I said - everyone carries a computer or two these days, so there is probably a lot of work that could be done to simplify the transition via good apps.

Re: It's time for the US to use the metric system

#54

The strange thing about articles like this is that they seem to assume that converting between units is something that happens all the time, such that doing so is a huge drain on the economy and engineering time. I don't know if my experience is the common one - but with a few exceptions (inches/feet, oz/pounds) such conversions seem kind of rare. Instead, you pick an appropriately sized unit to begin with, and stick…

I am not sure if this fully answers your questions, but one of the places where unit conversions happens a lot when doing customary unit engineering calculations is dealing with various constants/properties. For example, you might get the specific heat capacity of some material in terms of gallons, but you're dealing with ounces of fluid, and so you stick a conversion in there. It's certainly kind of niche, but it's really annoying to deal with.

But agreed on the half-assed metrification. I'm from Canada. I still buy pop and beer in 355ml cans, 591ml coke bottles, 600ml pepsi bottles, and 2L big bottles. My wood is still sized in inches (or nominal inches).

(I fully support SI though. In theory, I no longer need to memorize a whole set of conversion constants. In practice, I live in Canada, so I still need them).

Re: It's time for the US to use the metric system

#55
In the EU, when we had to change from national currencies to Euro, the outcry was big -- because everybody was only able to "measure" money in the old currency. That even exactly this currency changed over the past decades very much, seemed to be not in the minds.

I guess, there are still people out there, which recalculate into Francs or Marks, or whatsoever -- but I think most Europeans have adapted.

So, when "old Europe" can change -- why not "modern USA"?

Re: It's time for the US to use the metric system

#56

In US schools are children taught metric or imperial? For example when measuring a liquid for a science experiment are measurements made in millilitres?

When we're young we're taught the imperial method since it's the customary system. Once we start getting into science classes it's all metric. Still, outside of science classes (and the military) we don't use it at all.

Which means we don't have a good working model in our heads of what a kg feels like or how warm a 30 degC day is...that sort of thing. I think most Americans have a pretty good feel for what a liter is since lots of drinks sell in that volume (and it's almost the same as a quart). But I think it'll be a cold day in hell before we cook in metric...customary units are pretty handy with home-style cooking since they line up pretty well with the size of stuff that's already in your kitchen (a cup, a teaspoon) and all our measuring and cooking equipment is in imperial. Actually, converting imperial measurements is a rotten mess, but using them in practice is pretty convenient. The sizes of most things just sort of intuitively makes sense on a human labor sort of scale (a pound of food turns out to be a nice filling meal, you can estimate inches with your thumb and feet with your forearm, 0 degF is colder than frozen water and just at the edge of tolerable, while 100 degF is just at the edge of tolerable on the other end of the scale even if water it nowhere near boiling, a pint is a good size for a beer, a yard is about a man's reach, an acre is about the size of a field a person can work in a day, etc.) -- there's some sense to them.

The military uses metric for most things however (due to constant international collaboration) and you'll find military people have a better grasp of the feel for most metric units, especially distance.

It's a bit like in England though where metric is taught, but people still colloquially refer to people in stones or distance in miles and beer in pints. Actually lots of countries still use their customary measurements [1] in certain niches, Koreans still use the pyeong 평 [2] when dealing with real estate for example.

I've been fortunate enough to travel quite a bit to metric using countries and have developed enough sense to quickly convert in my head. I know what a good room temperature is (22-24 degC), but I have no idea if I should bring a jacket when the weather is 15 deg C or not and the difference of 30 - 40 deg C always catches me by surprise. I have good feel for ml, cl and liters (lots of wine drinking), an okay one for kph, meters and km (driving and walking most places).

But g and kg continue to stupify me since I can't seem to find a useful frame of reference for those measures. I just end up mentally doubling all kg to pounds where it makes sense. I mean, what common thing weighs a kg? Everything at 1 kg just seems to be too heavy and to make use of it you end up sectioning it into grams, the liter is the same, too much liquid for anything useful, except I can usually split 1000 ml of wine with my wife over a long relaxing dinner and that's my reference point. And I guess that's the problem, I end up using fractions in decimal countries like I'd use them in the U.S. (most imperial units have handy fractions: 1/3, 1/4, 1/2, 1/12, but metric countries work better with decimals.

1 - https://en.wikipedia.org/wiki/Customary_units_of_measure#His...

2 - https://en.wikipedia.org/wiki/Pyeong

Re: It's time for the US to use the metric system

#57

The strange thing about articles like this is that they seem to assume that converting between units is something that happens all the time, such that doing so is a huge drain on the economy and engineering time. I don't know if my experience is the common one - but with a few exceptions (inches/feet, oz/pounds) such conversions seem kind of rare. Instead, you pick an appropriately sized unit to begin with, and stick…

Probably a host of stuff from one less NASA orbiter crashing, down to not having the sticker on millions of car B pillars printed with imperial and metric tyre pressures.

There are lots of downsides, it's interesting you give a construction example; in the UK we have houses built from imperial bricks. Metric bricks aren't the same size, but a conveniently round number in millimetres. A house I'm buying was built in imperial bricks and someone with not quite enough sense has filled in some old doorways with metric bricks.

The costs of maintaining different systems aren't large but accumulate indefinitely, the cost to switch is finite.

Re: It's time for the US to use the metric system

#58
post #23

Earlier quoted context omitted.

> Fahrenheit (since this is a non-linear transform) huh?

There's a constant offset between F and C, so it's not linear in the actual engineering/math (or whatever) sense.

It's not proportional, but the equation for going from one to another is that of a line.

I would think this would be called linear, but that mean something more specific?

Re: It's time for the US to use the metric system

#59

Some thoughts on a conversion that I don't generally see brought up: * From an economic standpoint, the US is a big enough market that it is profitable to make things in weird US units, you have 350M people to sell to, most of whom are pretty well off by world standards. It makes sense to make a line catering to them. If businesses can start making a true or good economic argument it will happen more. * Tooling that…

I am not sure, if the paper sizes (A4, ...) are belonging to the metric system ... but of course, here a standardization would be nice. At least software producers seem to know (most of them) now, that there are also other formats as the "standard US formats".

Re: It's time for the US to use the metric system

#60
post #7

Good luck trying to change something that's part of a cultural identity. Irish are catholic not because religion is actually something positive, but because it's a contrast with the British church, and part of their cultural identity.

> Irish are catholic not because religion is actually something positive, but because it's a contrast with the British church, and part of their cultural identity.

Hmmm, I think you'll find that Catholicism is older than the Church of England (not that this relates to the metric system in any way). The English changed from being Catholic to Church of England during Henry VIII's reign. The Irish largely remained Catholic.

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