International System of Units overhauled in historic vote • Hacker News Board

Re: International System of Units overhauled in historic vote

#491

Post by afpx » Sat, Nov 17, 2018, 1:21 PM UTC

afpx wrote: post #467

pcnix wrote: post #459

Earlier quoted context omitted.

That's false, the Imperial system is pretty bad at doubling or halving. What's double of 3.7 feet? Or half of 1.5? What is 3.7 feet even? Is it 3 feet 7 inches or 3 feet plus 7th of a feet (This last question is a nitpick) Any of these in metric are super simple, but just harder to do in base-12.

In practice, as the previous poster pointed out, Imperial numbers are rational, not real. You wouldn’t normally experience ‘3.7’ feet. Don’t get me wrong, I’m certainly not a proponent of the Imperial system (for instance, calculating prices for groceries is painful). I am just pointing out that the metric system doesn’t take into account many Human use cases (Base-10 isn’t great for Humans). It was a system forced u…

Americans are pretty awesome.

Re: International System of Units overhauled in historic vote

#492

Post by eyko » Sat, Nov 17, 2018, 1:47 PM UTC

mastazi wrote: post #408

School-Cotton wrote: post #399

Earlier quoted context omitted.

I suspect that only a minority of people in metric-using countries -- those with basic chemistry knowledge fresh in their mind -- know that "one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade". Probably a similar number of Americans know the same facts. And any of them would answer "How much energy does it take to boil a room-…

> I suspect that only a minority of people in metric-using countries -- those with basic chemistry knowledge fresh in their mind -- know that This is not the case. This part: "one milliliter of water occupies one cubic centimeter, weighs one gram" is known by most people, even kids in primary school. In other words everyone knows that a litre of water weighs one kilogram, and that there are 1000 litres in a square me…

You probably meant cubic metre?

Re: International System of Units overhauled in historic vote

#493

Post by sonnyblarney » Sat, Nov 17, 2018, 1:49 PM UTC

ygra wrote: post #488

sonnyblarney wrote: post #476

Earlier quoted context omitted.

"Recipes in cups are one thing I cannot understand" ?? You drink out of cups every day; this is what humans, even you understand. 'A scale' is inapplicable while you're buying food or reading labels. Why use a scale when everyone knows what a cup and teaspoon are? They are human measurements. But it doesn't matter what you use, what matters is what people understand, and they don't understand grams and millilitres. I…

My cupboard has cups in all kinds of sizes. Which one is the right one to use as a measurement? And for baking there's quite a big difference if my cups are 150 ml or 350 ml, especially when paired with counted ingredients like eggs. That's the problem with cups.

All of your regular coffee cups are exactly 250ml.

Regular people use them for basic baking all the time, like making pancakes.

'Cups' are still better measures than ml because even you, in your self-acclaimed ignorance have a sense of how much a cup is whereas people do not have any idea how much '300ml' is.

Canadians have no clue what 10ml of anything is.

Canadians will continue to use feet and pounds for personal measure, despite being surrounded by total metric system - that should tell you something.

Do you order beer in ml? Or pints?

Seriously, do you know anyone that orders a 473ml of beer?

So why pints? And not ml? Because it makes sense.

Everything should be in metric, but many things should also be Imperial because metric is not useful for many common measurements.

The entire construction industry in Canada still uses Imperial, and it also weirdly makes sense. Inches and feet are slightly more approachable at smaller scale.

Re: International System of Units overhauled in historic vote

#494

Post by andrewaylett » Sat, Nov 17, 2018, 1:59 PM UTC

jdhzzz wrote: post #487

eadmund wrote: post #381

Earlier quoted context omitted.

Actually, assuming room temperature is 60° and you’re at sea level, it’d take 1,216 BTUs to bring a gallon of water to a boil. A BTU is the amount of heat (which is energy) required to heat one pound of water one Fahrenheit degree; a pound of water is a pint; there are 8 pints in a gallon (2 pints in a quart, 2 quarts in a pottle, 2 pottles in a gallon). So, 8 * (212-60) = 1,216.

"A pint's a pound the world around." I never knew whether that came from the fact that both are 16 ounces or because a pint of water weighs a pound (approximately). I prefer to think it's the latter. Makes it so I can remember that a gallon of water is approximately 8 pounds. 5 gallon pail mostly full, probably 35 pounds. Nice.

Except it's not, as a pint is 20 fl.oz, while a pound is only 16 oz.

UK resident here, in case you couldn't tell :).

Re: International System of Units overhauled in historic vote

#495

Post by sjy » Sat, Nov 17, 2018, 2:01 PM UTC

evil-olive wrote: post #380

anamexis wrote: post #294

Earlier quoted context omitted.

I'll concede that freezing is very important to a lot of people, but at the same time, I don't think it's particularly onerous to remember that the freezing point is 32 degrees. As far as boiling and cooking, I would argue that there is no magic number anyways, since boiling point is variable by elevation. At 7500 feet / ~2250 meters, water boils at 198°F.

> As far as boiling and cooking, I would argue that there is no magic number anyways, since boiling point is variable by elevation. At 7500 feet / ~2250 meters, water boils at 198°F. That's an excellent point, let's examine the relationship between altitude and boiling point, in both American units and everywhere-else-in-the-world units [0]: 5000 feet -> 202.97 F 7500 feet -> 198.33 10000 feet -> 193.6 F Compared to:…

If going from 100 °C to 90 °C was a 10% decrease, then going from 0 °C to 1 °C would be an ∞% increase. Metric units are superior to imperial for many reasons, but this isn’t one of them.

Re: International System of Units overhauled in historic vote

#496

Post by andrewaylett » Sat, Nov 17, 2018, 2:02 PM UTC

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.

A pint is a pound so long as you're in the US. Everywhere else, it's 20 fl.oz, while a pound is 16 oz.

Re: International System of Units overhauled in historic vote

#497

Post by jimktrains2 » Sat, Nov 17, 2018, 2:28 PM UTC

jbay808 wrote: post #440

jimktrains2 wrote: post #154

Earlier quoted context omitted.

I've actually become quite fond of liquids being powers of 2 and lengths being broken fractionally. The base unit doesn't really matter (and you can always use decimal length, as is often done when building precision items). So, for liquids, 2 tablespoon = 1 ounce 2 ounce = 1 jack 2 jack = 1 gill 2 gills = 1 cup 2 cup = 1 pint 2 pint = 1 quart 2 quart = 1 pottle ( ½ gallon) 2 pottle = 1 gallon I find it much easier t…

Fractions are nice when the numerator is always 1. They're a pain when it isn't; sorting drill bits or buying material from McMaster Carr, you constantly have to sort out whether 17/64 is larger or smaller than 3/8, and by how much, and it becomes quite burdensome.

It's not immediate like it would be with decimals, but ⅜ -> 6/16 -> 12/32 -> 24/64 is still something I find I can do (and track) in my head with ease. Yeah, doing it repeatedly on a task would get a little tiresome. Also, who knows where the numbered and lettered series drill bits fit in without a chart.

The fractional system isn't perfect for all use cases by any means. (My understanding is that a lot of machining just deals with decimal inches directly.) I just find it convenient for many everyday tasks. I'm also weird, I guess, in that arithmetic on fractions feels easier than on decimals.

Thinking more about my original statement, a lot of it has to do with halving (e.g. finding a center) being a common operation for many tasks. It also helps that most things are sold in those fractional increments too :)

Re: International System of Units overhauled in historic vote

#498

Post by analog31 » Sat, Nov 17, 2018, 2:34 PM UTC

blhack wrote: post #232

kibwen wrote: post #188

See, the US wasn't being stubborn in not adopting metric, it was just waiting patiently for it to progress from beta to 1.0. :) (Fun fact: all the US customary units have been officially defined in terms of their metric counterparts since 1893: https://www.nist.gov/sites/default/files/documents/pml/wmd/m... )

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…

Just as a side note, the US system gets worse and worse when you look beyond the everyday units of measure.

Sure, inches are great, but below 1/4", screws are in a numbered system (higher number is larger) while the corresponding drill bits are in a different numbered system (higher number is smaller) or lettered (A to Z). Wire and sheet metal gage numbers are still different.

An #8-32 thread takes a #29 tap drill...

https://www.lincolnmachine.com/tap_drill_chart.html

Re: International System of Units overhauled in historic vote

#499

Post by iharhajster » Sat, Nov 17, 2018, 2:41 PM UTC

For an engineer it's quite an anventure throughout your career discovering how many "languages" people speak: imperial, metric, IEC, ANSI, metric thread, NPT thread, all the units and industrial standards. And still foreign ISS parts mate in orbit on their first date. Or ITER parts fit toghether in plant. That's electrifying and inspiring.

Re: International System of Units overhauled in historic vote

#500

Post by rumcajz » Sat, Nov 17, 2018, 2:44 PM UTC

kibwen wrote: post #188

See, the US wasn't being stubborn in not adopting metric, it was just waiting patiently for it to progress from beta to 1.0. :) (Fun fact: all the US customary units have been officially defined in terms of their metric counterparts since 1893: https://www.nist.gov/sites/default/files/documents/pml/wmd/m... )

No, it were actually pirates at fault of America not adopting metric: https://www.npr.org/sections/thetwo-way/2017/12/28/574044232...