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International System of Units overhauled in historic vote

npl.co.uk

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Re: International System of Units overhauled in historic vote

#531

Post by njarboe »

thrower123 wrote: post #393
EricBurnett wrote: post #324

Earlier quoted context omitted.

Hmm, good for usage you say. Ok, let's stick to "standard" imperial units. How many feet in a yard? Yards in a mile? What the hell is a quart? And since base 12 is great, what is 12 feet called? 144 feet? A 12th of an inch? Or, ounces: How many ounces in a gallon? A pound? And how many _kinds_ of ounces are there, anyways? Fun fact: The term “ounce” is of Latin origin from the word “uncia” which means “a twelfth part…

A yard is three feet, or about the length of a man's stride. A quart is about the maximum amount of whiskey one can drink without dying. A pint's a pound, the world around. My favorite is the cord, which is 128 cubic feet, or more often a stack of firewood 4 feet tall by four feet wide by eight feet long.

The cord is also the size of the standard US pickup truck bed with the wood stacked up about cab height.

Re: International System of Units overhauled in historic vote

#532

Post by njarboe »

KozmoNau7 wrote: post #421
Just_Smith wrote: post #300

Earlier quoted context omitted.

Your absolutism is a bit silly. I don't think the Imperial system is good for anything beyond construction or cooking, but there's a reason it excels those areas. And it's exactly because it's more usable by humans in certain contexts (like construction or cooking). 1/3 of a meter should not be an irrational number - how is that "optimized for humans"? A scalable system that shares the divisibility of the foot would…

The imperial system is terrible for cooking, in my experience as a home cook and baker. Measuring dry goods by volume instead of by weight? Good luck ever getting consistent results. Base 10 math is the most intuitive for humans. Fractions are an abomination.

Math isn't intuitive for humans. It takes a lot of work to learn it and most people don't remember any of it past school age. If we taught base 12 instead of 10 it would be just as intuitive.

Re: International System of Units overhauled in historic vote

#533

Post by njarboe »

fingerlocks wrote: post #451
starbeast wrote: post #400

Earlier quoted context omitted.

Can I pick the blade thickness?

Sure, kerf is less important than the thickness of your pencil line in terms of accuracy

Place the center of your line at the correct location.

Re: International System of Units overhauled in historic vote

#534

Post by njarboe »

jhasse wrote: post #470
ubernostrum wrote: post #289

Earlier quoted context omitted.

a kilogram of water is also a liter I have never, in around four decades of living, had an actual need to determine the mass of a given volume of water, or the volume of a given mass of water. When cooking, I routinely need to split some quantity of an ingredient into thirds or quarters. Yet I am also constantly told that I'm ignorant and backwards and irrational for preferring a system that optimizes for the latter,…

> When cooking, I routinely need to split some quantity of an ingredient into thirds or quarters. Why?

Recipe feeds six. Making it for two.

Re: International System of Units overhauled in historic vote

#535

Post by bonzini »

Jedi72 wrote: post #45
3pt14159 wrote: post #12

This is probably the dumbest thing I'll type on HN. In university I just gave up trying to understand why we even needed the Avogadro constant / mole as a fundamental constant. It still confuses me. Why have a difference between molar mass and mass? Why couldn't it just be "1" and everything else change around it?

No I agree, it seems stupid. What we did is take a block of metal and call it a kilogram, figure out how many atoms are in 1/1000 of it (a gram) and call that a mole. What we should do is redefine the gram to be whatever 1e10 atoms of Hydrogen weighs, or something similar. When I read the headline I thought thats what they did, and I admit first reaction was "oh god I'm going to be dealing with conversions and associ…

> What we should do is redefine the gram to be whatever 1e10 atoms of Hydrogen weighs, or something similar.

That was actually an alternative proposal for redefining the kg. The kg would have been 1000/28 the weight of a mole of silicon-28; you could build a sample by counting 6.023x10^26/28 atoms of silicon-28, and making a sphere out of them.

Initially the watt balance seemed to be less precise than atom counting, but then it was improved to a point where defining the kg on top of the mole became less convenient than the definition they are adopting now.

Re: International System of Units overhauled in historic vote

#536

Post by madstap »

akira2501 wrote: post #278
naikrovek wrote: post #238

Earlier quoted context omitted.

You are definitely (and thankfully) not the norm. Imperial units are awful. They're more ... human, maybe, in that a foot is about one human foot long, and that an inch is about one human thumb width, and how 0F feels "pretty cold" and 100F feels "pretty hot", and to me the charm of imperial units begins and ends right there. Those are literally the only redeemable qualities about imperial units, and they have nothin…

> They're more ... human, maybe I think both systems of units typical cases are dominated by human factors. Anecdotally, humans tend to use one of three scales for their preferred choice of measurement and they tend to be smaller-than-human, human, larger-than-human. For example, the km. I see mm, m and km used quite often.. but the other bases are almost never used. A prime case for this is "what is the distance to…

In Norway hectograms are frequently used. We use them for things like potato salad at the deli counter, pick'n mix candy, berries and small-time-dealer quantities of hash.

Re: International System of Units overhauled in historic vote

#537

Post by KozmoNau7 »

njarboe wrote: post #532
KozmoNau7 wrote: post #421

Earlier quoted context omitted.

The imperial system is terrible for cooking, in my experience as a home cook and baker. Measuring dry goods by volume instead of by weight? Good luck ever getting consistent results. Base 10 math is the most intuitive for humans. Fractions are an abomination.

Math isn't intuitive for humans. It takes a lot of work to learn it and most people don't remember any of it past school age. If we taught base 12 instead of 10 it would be just as intuitive.

But we don't. The number system used in the western world is base 10. So why add base 12 on top of that?

Re: International System of Units overhauled in historic vote

#538

Post by njarboe »

gilbetron wrote: post #504
blhack wrote: post #232

Earlier quoted context omitted.

I'm one of the weird people that actually really likes imperial units. For instance: 1 foot -- base 12. This is a superior base to 10. It can be easily divided into 4ths, 3rd, and 2nds. Base 10 can only easily be divided into 2nds. 1 inch -- an easily identifiable unit of measure for smallish things. About the width of my thumb. A pretty good unit. For low precision, inches become 1/2, 1/4, 1/8, 1/6, 1/64, etc. Each…

I'm glad you made this point, because I am the one that usually does and gets hammered for daring to even hint that imperial might not be totally insane! The temperature one I've always found compelling. Most humans only rarely experience temperatures outside of 0-100F. That makes sense to me. Celsius makes little sense, except for 0 being when water freezes. It compacts the scale too much for everyday use. However,…

A popular unit for a large beer is the "40" which is what a 40 ounce bottle of beer is called. About 1.2 liters, but not a size found in "respectable" households.

Re: International System of Units overhauled in historic vote

#539

Post by thaumasiotes »

kiriakasis wrote: post #481
thaumasiotes wrote: post #382

Earlier quoted context omitted.

That's not a base unit, or a unit of any kind. What's it doing in a list of SI base units?

Or you can say it is the conversion between a gram and a dalton, which is the same but more complex as it is now intertwined with the gram

I already said exactly that:

>>> Avogadro's number, and therefore the mole, is the conversion factor between atomic mass units and grams.

But that doesn't intertwine anything with grams. I went on to say

>>> Similarly, 3 is the conversion factor between feet and yards, but nobody thinks 3 is a fundamental base unit of the imperial system.

>>> It would be total nonsense to say that yards are defined by reference to 3.

Re: International System of Units overhauled in historic vote

#540

Post by posterboy »

toasterlovin wrote: post #509
kiriakasis wrote: post #460

Earlier quoted context omitted.

Nice point, but it is really the typical elementary school topic "one cubic centimeter of water is one gram, one cubic decimeter is one kilograms, one cubic meter is one THOUSAND!!! kilograms" Then in highschool it is used for physics and unit of measurements and everyone knows that you can just weight milk and water when you cook with 1kg = 1liter

Normal people don’t do that. They just know that a gallon is a gallon, a meter is a meter, a pound is a pound, etc. People rarely have need to convert between mass and volume. And they don’t weigh their milk or water.

Because if they had to, they'd rather find a jug than a calculator.
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