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The super-slow conversion of the U.S. to metric (2025)

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Re: The super-slow conversion of the U.S. to metric (2025)

#291

Post by cogman10 »

beloch wrote: post #242

To those who cling to customary units because... 1. "They're more intuitive". They're not. You're just familiar with what 70 F feels like. If you're used to metric, 70 F is meaningless, but you intuitively know what 20 C feels like. 2. "Metric leads to lots of awkward numbers." All systems will fortuitously have round numbers in some contexts and awkward numbers in others. Customary units are different in that there…

Temperature is the worst metric unit to pick for this. Both the imperial and metric versions of temperature are completely arbitrary. It's really baffling to me that THIS is the one that most people talking about metric superiority cling to. Where metric shines is when you talk about subunits like mg vs g vs kg. You don't do that with temperature almost ever. So so what if water boils at 212F vs 100C? Pinning 100 at the boiling point of pure water at standard atmospheric pressure is every bit as arbitrary as Fs original 100F pin to the internal body temperature of a horse.

Otherwise I agree with you. I just wish stronger arguments would be made. Measuring distance, speed, weight, volume in metric makes a lot more sense and is more intuitive. It's easy to relate 300mL to 1L. or 1cm to 1m to 1km. And that is where most of the value of metric comes from. The fact that we basically never think in terms of kC or mC is why using temperature is very weak.

Re: The super-slow conversion of the U.S. to metric (2025)

#292

Post by samus »

ericmay wrote: post #263
samus wrote: post #231

Earlier quoted context omitted.

> Temperatures in most places are within those bounds That seems to be a quite arbitrary and insufficient criterion. As soon as I start cooking or preparing a warm drink I already step way outside these boundaries. In defense of the relevance of the Celsius scale in daily life: its endpoints represent critical temperatures of the most important liquid to life on Earth at ~1 bar. And at temperatures of 0°C or less I s…

> How so? Celsius was proposed merely 18 years (1742) after Fahrenheit (1724). Sorry, I was attempting however poorly to reference the Imperial system historically, not Celsius versus Fahrenheit there which may have been confusing on my part. > In defense of the relevance of the Celsius scale in daily life: its endpoints represent critical temperatures of the most important liquid to life on Earth at ~1 bar. And at t…

> When I walk outside unless it's really cold I don't ever think about what temperature water freezes or boils, I want to know whether I am going to sweat, whether I'm in California, or whether I'm going to freeze my butt off when it's 14 degrees out.

In either system that's just a matter of remembering a few numbers. And it anyway doesn't give the full picture since humidity and wind speed play a huge role in how it actually feels like and what clothing one should wear.

Re: The super-slow conversion of the U.S. to metric (2025)

#293

Post by nine_k »

beloch wrote: post #242

To those who cling to customary units because... 1. "They're more intuitive". They're not. You're just familiar with what 70 F feels like. If you're used to metric, 70 F is meaningless, but you intuitively know what 20 C feels like. 2. "Metric leads to lots of awkward numbers." All systems will fortuitously have round numbers in some contexts and awkward numbers in others. Customary units are different in that there…

"Customary units" are a varied bunch.

The inch-foot-yard-mile scale are not uniform, and not easy to calculate. Their only convenience is easy divisibility by 3. The practical example of uniform scale of this kind is seconds-minutes-hours, which, I suppose, go all the way down to the Sumerian 60-based scale. The mm-cm-m-km are much easier in practice.

Sub-inch units are an honest binary system, and as such is pretty practical. The fact that it's written as a ratio of decimal numbers is sometimes unhelpful though, comparing 7/16" and 1/2" takes either mental gymnastics or memorization. Millimeters are somehow more convenient here, but not by such a large margin as with inch-foot-yard scale.

The Fahrenheit scale is uselessly arbitrary; 0°F does not match anything useful, and 100°F is not that useful either.

The only mile that makes sense is the nautical mile, 1 nm matches 1" of arc on the map / globe, the same way as 1 km is 1/40,000th of the arc.

Re: The super-slow conversion of the U.S. to metric (2025)

#294

Post by cogman10 »

nine_k wrote: post #284
rconti wrote: post #268

Earlier quoted context omitted.

Counterpoint to #1, celsius increments are too large. I laugh every time I see a thermostat in a car or home that needs to have steps like 20, 20.5, 21, 21.5.. :)

Do you honestly notice the difference in comfort between 20°C and 20.5°C? I suspect even the heating element is not that precise, let alone the actual room temperature. They only case in daily practice where 1°C is too large is the difference between normal body temperature (36.5°C) and mild fever (37.0°C), but thermometers have to be graduated in much smaller subdivisions anyway.

> Do you honestly notice the difference in comfort between 20°C and 20.5°C?

Yeah, it's noticeable. That 0.5C move is roughly a 1F move. And there's definitely a noticeable difference between 71F, 72F, and 73F.

But I'd say that it ultimately only matters in human comfort and only when you are talking about room temps. Once you get outside that 70->75 range the exactness starts mattering a lot less. 80 and 85 both feel hot. 65 and 60 both feel cold.

Re: The super-slow conversion of the U.S. to metric (2025)

#295

Post by ericmay »

amanaplanacanal wrote: post #287
ericmay wrote: post #143

Earlier quoted context omitted.

Cognitive Architecture by Ann Sussman is probably the best single book about this topic that I've found. https://annsussman.com You may find this lecture of interest. I'm sorry I don't have anything shorter to read offhand. https://www.youtube.com/watch?v=LPjezxPl3FA -edit- This might get you closer though to the general theory: https://asla-ncc.org/the-built-environment-impacts-our-healt...

Thank you! I read the article in your edit, and the point about symmetry seems unrelated to the rest of the article, and doesn't mention any science. I'll have to research further. Intuitively it doesn't resonate with me. The environment humans evolved in (the natural world) doesn't have much of anything symmetrical, unless it was built by humans.

I'll see if I can find a better article. I think it's unfair for someone including me to say "go read a book" though the meat of the general theory is there in those books.

The research and science being done is measuring levels of stress relative to shapes and designs of buildings through eye-tracking software. So to really over-simplify, buildings that are asymmetrical or perhaps where the door is hard to find, or in some urban environments there specific features that cause stress and it is measurable.

> The environment humans evolved in (the natural world) doesn't have much of anything symmetrical, unless it was built by humans.

https://www.sciencekids.co.nz/images/pictures/plants/flower....

Re: The super-slow conversion of the U.S. to metric (2025)

#296

Post by ericmay »

relaxing wrote: post #282
ericmay wrote: post #125

Earlier quoted context omitted.

> You think Frank Lloyd Wright designed big picture windows and open floor plans because he was afraid of humanity? He was afraid so he tried to induce fear? No, I was speaking about the exterior. The blending in of the surroundings, and hiding of things like the entrance are the hallmark of post-war architectural trends. Not that I'm claiming Lloyd suffered from the same PTSD that returning American veterans did, bu…

> No, I was speaking about the exterior. But windows are exterior? The idea that massing of interior influences the form of the exterior is part of Wright's philosophy. I don't believe you know what you speak of. > The blending in of the surroundings, and hiding of things like the entrance are the hallmark of post-war architectural trends. Not that I'm claiming Lloyd suffered from the same PTSD that returning America…

> I don't believe you know what you speak of.

Ok, then I guess we don't need to discuss anything further :)

Re: The super-slow conversion of the U.S. to metric (2025)

#297

Post by acdha »

bigstrat2003 wrote: post #256
beloch wrote: post #242

To those who cling to customary units because... 1. "They're more intuitive". They're not. You're just familiar with what 70 F feels like. If you're used to metric, 70 F is meaningless, but you intuitively know what 20 C feels like. 2. "Metric leads to lots of awkward numbers." All systems will fortuitously have round numbers in some contexts and awkward numbers in others. Customary units are different in that there…

> You're already using metric units. No we aren't. It doesn't matter what the units are defined as, that is not what determines which units we are using.

In many cases we are, though. A ton of machined things use metric units (and thus need metric tools), and that’s spreading into a lot of other areas like medicine and food packaging. It’s nowhere near absolute but the trend is noticeable.

Re: The super-slow conversion of the U.S. to metric (2025)

#298

Post by psadauskas »

beloch wrote: post #242

To those who cling to customary units because... 1. "They're more intuitive". They're not. You're just familiar with what 70 F feels like. If you're used to metric, 70 F is meaningless, but you intuitively know what 20 C feels like. 2. "Metric leads to lots of awkward numbers." All systems will fortuitously have round numbers in some contexts and awkward numbers in others. Customary units are different in that there…

I read a study many years ago, I haven't been able to find it for awhile. It took people who had grown up using each system, and asked them to estimate things just by guessing. For example, "How long is that wall?" or "How far is it from here to the post office?" or "How heavy is this paperweight?". People who'd grown up using customary were significantly more accurate in their guesses.

The study surmised it was because those units had been developed over millennia to be useful at human scales. When eyeballing the length of a wall, centimeters are too granular and meters are to course, but feet are "just right". You might guess a wall is 12 feet long, and be pretty close, but 3 or 4 meters aren't that accurate, and nobody really guesses 3.5 meters.

Same with temperature. 0 - 100°F is about all we as humans will usually experience, so its very convenient when talking about the weather or HVAC thermostats.

They are worse when doing math or conversions, and while that's annoying for scientists and engineers, in most people's everyday lives it comes up so infrequently it doesn't really matter. If something is less than a mile, you don't suddenly convert to feet and do math, you just say "about a half mile".

Personally, I do woodworking (which in the US is always imperial) and 3d-printing (which is always metric), and often combine the two. When doing woodworking or carpentry, its nice that a foot is evenly divisible by 3 or 6, or that half of 3/8ths of an inch is 3/16ths.

Re: The super-slow conversion of the U.S. to metric (2025)

#299

Post by klaff »

ericmay wrote: post #86
JKCalhoun wrote: post #77

"Back when I was a Catholic-school kid in northern Wisconsin, my school lessons briefly focused on the metric system. This was in the late 1970s." Man, the progressive school (Comanche Elementary in Overland Park, Kansas!) must have had a huge impact on my life. In addition to open classrooms (I was in Unit 5, not 4th Grade), team teaching, a focus on experimental science, a circular layout to the school with a sunke…

> Yeah, we went over the Metric System that whole year. I can still sing the "Metric Family" song from the film on metric units ("Kilo", "Milli", etc.). And to my young an impressionable mind, the U.S. was joining the rest of the world "Free World" in a kind of Star-Trek-like casting aside of the old things that divided us—joining each other with a focus on progress, science, space… I’ve always found this peculiar be…

As a hardware engineer I've been primarily using metric for over three decades, and like the machinist quoted in the article have had to deal with bullshit of converting back and forth. It's not just about inches and centimeters.

If you're working with small motors, the Ke (back-EMF constant) and Kt (torque constant) have different and crazy Reagan units (e.g. V/krpm, inch-ounces/A) but in SI they have units of V/(rd/s) and N-m/A, which if you crunch them down to kg, m, etc. are identical and so have the same numerical value (because they represent the same transformation from electric to mechanical or vice-versa). Power is the product of voltage and current or torque and speed - if you use the SI units no conversion required. Inertia was confusing as hell, some vendors specified it in MOISS, or milli-ounce-inches-seconds-squared, not only involving different unit but you can also get balled up in the mass vs force confusions.

Converting a drawing from one system to the other perfectly is practically impossible. Conversions can't always be exact and because tolerances are commonly specified in round numbers within a system.

In my garage I still have both metric and Reagan-unit tools. Even though my cars, even the American ones have been metric since the '80s, I have to have the other tools for other household things like the garage doors!

And then there's the tire size abomination - an unholy union - a 255R70-14 is 255 mm wide at the bulge, the sidewall height is 70% of that, and the rim diameter is 14 inches.

I agree that 1 °C is too big a step when dealing with thermostats but that's easily solved by using 0.5 °C resolution.

Re: The super-slow conversion of the U.S. to metric (2025)

#300

Post by mitthrowaway2 »

cogman10 wrote: post #291
beloch wrote: post #242

To those who cling to customary units because... 1. "They're more intuitive". They're not. You're just familiar with what 70 F feels like. If you're used to metric, 70 F is meaningless, but you intuitively know what 20 C feels like. 2. "Metric leads to lots of awkward numbers." All systems will fortuitously have round numbers in some contexts and awkward numbers in others. Customary units are different in that there…

Temperature is the worst metric unit to pick for this. Both the imperial and metric versions of temperature are completely arbitrary. It's really baffling to me that THIS is the one that most people talking about metric superiority cling to. Where metric shines is when you talk about subunits like mg vs g vs kg. You don't do that with temperature almost ever. So so what if water boils at 212F vs 100C? Pinning 100 at…

(A standard horse in standard health, of course).
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