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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)

#261

Post by vablings »

alnwlsn wrote: post #169

>They specify dimensions in feet, inches, and fractions of an inch. But not all of them do. There are many more fun and exciting non-metric measurements you might encounter than plain old fractional inches. A fabricator might encounter sheet metal thickness in "gauge". Wire sizes, ammunition, and machine screws also come in "gauge" sizes but all four are different scales. US drills come not only in fractional inch si…

Metal hardness having a bunch of different units is quite annoying but also interesting.

There are quite a few ways to measure the hardness the most interesting being Vickers. You plunge a diamond of a known force into a surface and measure the size of the indentation. This is surprisingly accurate but does leave a small diamond mark on your surface.

With a sufficiently small part a blacksmith or other folks can determine the hardness of a steel just by listening to how it rings. Hey, you can also test for cracks with a ring test, the most common use is ring-testing a vitrified grinding wheel to see if there is no crack

Alot of engineering is just listen and maybe the odd hit with a hammer

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

#262

Post by tzs »

technothrasher wrote: post #149
ericmay wrote: post #86

Earlier quoted context omitted.

> 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…

> the useful scale of Fahrenheit is far superior 0-100 versus 0-32. Well, first of all, I'm not sure why you're defining those scales as the "useful" ones. They don't even equate to each other. But why are you arbitrarily using 100 as the end of your Fahrenheit scale? Just so you can declare it 'Metric-y'? If you read his paper, Fahrenheit's scale is actually 0-96.

The things that make the metric system superior to prior systems are:

• Using a uniform set of prefixes to designate multiples and divisions of the base units.

Having one unit of say, volume (the liter), and then using prefixes when we need smaller or larger units is way better than having cups, pints, quarts, gallons, pecks, and many more.

• Having those prefixes mean powers of 10. That fits in well with our use of decimal arithmetic.

It is the first one that is most important.

For temperature there's nothing actually 'Metric-y' about Celsius (or Kelvin), because in most cases people don't use multiples or divisions of the base unit. This includes in science and engineering. An astronomer would say (and write in their paper) that a star has a temperature of 7000 K, not 7 kiloK. They would say a neutron star has a core temperature of 100 trillion K, not 100 TK or 100 teraK.

At the low end there is more use of prefixes. The scientists that work near absolute 0 do often use millikelvin and microkelvin. They also often don't. Both 10^-2 Kelvin and 10 mK would usually be acceptable.

A metric system with the same meter, liter, and gram as the current one but that had picked F and R instead of C and K would work fine and be just as 'Metric-y' as the current metric system.

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

#263

Post by ericmay »

samus wrote: post #231
ericmay wrote: post #166

Earlier quoted context omitted.

Well even 0-96 would be better, but I think 0-100 scales are more useful. Temperatures in most places are within those bounds and it's like a test you are graded on. You get a 0 on the test, that's really cold. You get a 100 - smoking hot. I'm not 100% sure of the normal upper/lower bounds in everyday life for most people on the planet for Celsius, but let's say it's 0-32. It' just feels weird to me to be operating o…

> 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 temperatures of 0°C or less I stand at danger of not just hypothermia, but frostbite.

Right, incredibly important. I guess I would say I prefer Fahrenheit as a measurement of air temperature, if that would be more sensible to understanding my own personal preference. 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.

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

#264

Post by samus »

Kim_Bruning wrote: post #120
cucumber3732842 wrote: post #113

Earlier quoted context omitted.

What you're ignoring is that a hundred plus or minus is a good range for average humans to grapple with and Fahrenheit splits the temperature swings in a given region across an approximately 100deg range. So using Fahrenheit results in a pretty decent "as high as it can be without being clumsy" measurement system that covers just about all earthly temperatures. If we only cared about increments of five or so degrees…

Eh, all the degrees (Celsius, Fahrenheit, Réaumur, etc) are all about equally bad. Nicest thing that can be said about Celsius is that it's decimal, connected to water (0=freezing, 100=boiling) so it plays well with the rest of metric. Kelvin is actually the most practical of the lot, FSVO [1]. It's not a 'degree', because it's anchored at absolute zero. It's just a bit unwieldy for our day-to-day, with room temperat…

Right, we are just arguing which is the most practical range. It's like choosing a calendar: we could define one using entirely metric time units, but nobody would want to use it as long as human civilization is anchored on Planet Earth.

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

#265

Post by zokier »

zahlman wrote: post #192
alnwlsn wrote: post #169

>They specify dimensions in feet, inches, and fractions of an inch. But not all of them do. There are many more fun and exciting non-metric measurements you might encounter than plain old fractional inches. A fabricator might encounter sheet metal thickness in "gauge". Wire sizes, ammunition, and machine screws also come in "gauge" sizes but all four are different scales. US drills come not only in fractional inch si…

Gauges are a measurement , but they aren't a unit . They don't necessarily have any linear correspondence to actual distance/volume/whatever, and in fact are typically inverse (higher number = smaller thing). And yes, they're categorical. (Sometimes you even see 00 as a gauge number.)

> Sometimes you even see 00 as a gauge number

or 0000. Which then can conveniently be abbreviated to 4/0.

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

#266

Post by rickydroll »

bigstrat2003 wrote: post #207
rickydroll wrote: post #191

Earlier quoted context omitted.

If you want to get even more divisive, try converting people to metric baking measurements. Baking bread and cakes is much more repeatable if you use mass rather than volume to measure ingredients. The results from this recipe were never consistent when I used volume measurements. I converted to mass in metric and now I get consistent results. adapted from: [ https://www.justsotasty.com/wprm_print/11594 ]( https://ww…

I use volume measurements for baking and I get consistent results all the time. Perhaps your recipe is especially gnarly, but that isn't true of all recipes.

Regular results from volumetric measurements are due to the process. For example, sifting the flour every time gives you a degree of consistency approaching that of a mass-based measurement. Mass-based measurements make it easier to have that precision in the baking process.

[edit: speech recognition error correction.]

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

#267

Post by bigstrat2003 »

ddellacosta wrote: post #203
gonzalohm wrote: post #89

Earlier quoted context omitted.

Interesting. As an European living in the US. The only US units that I find useful are cups, teaspoons and tablespoons. And that's only for cooking. It's way faster to measure volume than weight (although less accurate)

As a pretty experienced American home baker I don't understand how you can assert that it's faster to measure volume with cups or etc. than to put a bowl on a scale and simply pour stuff in, measuring everything in grams. It's not even close in terms of speed, convenience, _and_ accuracy.

It is indeed not even close, but not in the way you are asserting. It takes a second to dip a measuring cup into the flour and level it off. So if I need 4c of flour, it takes me about 4 seconds. Meanwhile, to measure with a scale I have to slowly, carefully pour into the bowl so that I don't overshoot the amount I'm going for (and then then sometimes I overshoot and have to try to scoop the ingredient out a bit). Volume measurements are damn near an order of magnitude faster than weight measurements. And it's not like the extra accuracy from weight measurements is actually that important 95% of the time. Baking is not that precise, contrary to popular belief.

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

#268

Post by rconti »

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…

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.. :)

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

#269

Post by evil-olive »

eddyg wrote: post #110
threemux wrote: post #62

I'd part with cups and teaspoons/tablespoons and the like, but you'll pry inches/feet/yards and fahrenheit from my cold, dead hands. They're both more convenient for daily use. I think I'd prefer to keep miles as well but I don't have a good reason for that one. Fahrenheit has more precision without using decimals for the thing 99% of people are using temperature measurements for: air temp. Where I live, we generally…

Fahrenheit forever! 0°C.................100°C Cold Dead 0°F.................100°F Really Cold Really Hot

I see this argument repeated every single time someone tries to defend Fahrenheit.

if "room temperature" was smack in the middle, at 50 degF, you might have a point.

but no, it's pure post-hoc rationalization.

being naked at 0 degF will kill you. being naked at 100 degF will (usually) not. they're not remotely equivalent.

instead, think of it this way - human beings are mostly water, and 0 to 100 degC is "percentage of the way from water's freezing point to boiling point".

room temperature is "about 20% of the way to boiling". 40% or higher starts to cause our bodies to overheat. a typical sauna will be somewhere between 50 and 70% of the way.

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

#270

Post by zokier »

walthamstow wrote: post #134

You can keep your fahrenheit, your feet and your gallons, for all I care, but one thing I will never abide is bolts and nuts and drill bits coming in fractions of an inch.

Fractions of inch are still tolerable. But just having "#X" drills and screws is pretty silly. 7/32" might need some mental arithmetic, but #6 is just unknowable.
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