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International System of Units overhauled in historic vote

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Re: International System of Units overhauled in historic vote

#501

Post by cies »

atoav wrote: post #450
stass wrote: post #244

Earlier quoted context omitted.

What are the redeamable qualities of metric units?

The metric prefixes we know and love are a huge plus. If you convert from Volt to kV or to mV, you just need to move your comma. Ah see what I did there? I uses a metric prefix on a unit that is also used in the US. The thing is 1V is also 1Nm or 1J or 1Ws. So suddenly we have the meter there right besides the Newton. In fact if you look beyond "I build my own shed in the US"-scenarios, you will find the meter everyw…

V=J/C

V*C = J = Nm = Ws

Re: International System of Units overhauled in historic vote

#502

Post by bonzini »

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…

0 C = frozen, be careful

10 C = you need a jacket

15-25 C = great outdoors temperatures

20 C = good house temperature in the winter

25 C = good house temperature in the summer

30 C = too hot to go out doing physical activity, good for a picnic or a day at the beach

35 C = too hot to go out, period

40 C = hot bath

100 C = boiling water

Re: International System of Units overhauled in historic vote

#503

Post by TomMarius »

School-Cotton wrote: post #399
zmix wrote: post #366

Earlier quoted context omitted.

I understand, that you know the metric system, and, judging by your reasoning for your love for the imperial system, I understand, that you know what you are talking about (better than me). So, please, do not understand my comment as wanting to advise you! It's just, that I found this (on the web, one day) to express so much the way I (having grown up with the metric system) feel about it: "In metric, one milliliter…

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 "one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade".

They taught us that in 4th grade in cooking classes. Then they made us remember that in physics and chemistry classes 2 years later.

Re: International System of Units overhauled in historic vote

#504

Post by gilbetron »

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…

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, beyond basic human usage, I quickly switch to metric for anything involving actual math: simulation, science, finance, etc.

A "cup" is about what a normal drink is. A liter is an insane amount of liquid for everyday use. I don't sit down and drink a liter of wine, I have a cup of wine.

Re: International System of Units overhauled in historic vote

#505

Post by jnurmine »

anamexis wrote: post #240
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…

For most things, I think metric makes more sense, but I fully agree about temperatures. Fahrenheit is a superior scale for humans.

When it is 0 C, you can expect ice/snow outside.

Yesterday it was +20 C, today it is +25 C, so it is noticeably warmer.

-10 C tomorrow, so you'll need your woolen cap and padded jacket. -20 C and add a layer of underwear underneath and maybe a scarf.

When you boil water for tea (100 C) and don't want the water boiling but still hot, aim for 95 C.

When the inner temperature of salmon is +46 C, it is perfect, if it is +56 C or more, it is thoroughly cooked and will not taste soft anymore.

Usually the relevant difference is 5 or 10 degrees.

I don't even want to think what those examples could be as Fahrenheit.

My point is it is eventually a matter of what you are used to, but Celsius is more logical, because it is directly tied to water freezing and boiling.

For the most logical measurements we'd use Kelvin, but it is not practical! "Oh, it is 273.15 K outside, might be black ice on the roads"

Re: International System of Units overhauled in historic vote

#506

Post by mattraibert »

stickfigure wrote: post #419
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 not good for construction. Try measuring a 2x4 sometime. It's just an established convention. And it sucks.

A 2x4 is cut to 2" by 4" wet and shrinks when it is dried. I'm no huge fan, but this is not an issue with the imperial system.

Re: International System of Units overhauled in historic vote

#507

Post by emilfihlman »

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…

10 can easily be divided by into fifths.

Re: International System of Units overhauled in historic vote

#508

Post by DareRight »

School-Cotton wrote: post #407
DareRight wrote: post #391

Earlier quoted context omitted.

A numbering system based on human fingers would be base6.

You've got it backwards. Counting to ten on your fingers predates the concept of our modern positional number system by hundreds of thousands of years. That's why base 10 was already the well-established natural choice when that system was invented. Thinking that you could represent the quantity IIIIIIIIIIIIIIIIIIIII by the string "21" because it's 2 * 10 + 1, or similarly as "three fingers on left hand, three finger…

I'm not sure what your point is. A numbering system based on five-fingered hands is still base6. It doesn't make mathematical sense to argue that we learn base10 today because our hands have 5 fingers. Even if you argue that we have 10 total fingers, that's base11. Does anybody advocate that? How did we come to such an arbitrary thing as base ten?

Re: International System of Units overhauled in historic vote

#509

Post by toasterlovin »

kiriakasis wrote: post #460
toasterlovin wrote: post #422

Earlier quoted context omitted.

You comment on HN threads about measurement systems. You are not normal. None of us here are.

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.

Re: International System of Units overhauled in historic vote

#510

Post by tzs »

floatboth wrote: post #453
tzs wrote: post #313

Earlier quoted context omitted.

For mass, distance, area, and volume metric has an obvious advantage because for all of those we regularly deal with such a range of values that we want subunits, and basing those subunits on powers of 10 fits in much better with our number system and makes computation and conversion easier. This lets one make a pretty good argument that metric has advantages sufficient to justify having to buy new rulers and scales.…

> what is the justification for switching from F to C? The rest of the world already using ℃. Imagine no more dual scale thermometers, no more switches in weather apps, etc :D

Sorry, I guess I was not clear. I didn't mean what would be the justification for switching from F to C now in the US.

I meant what was the justification for adopting C initially for the metric system instead of using F?

For other metric units, there were serious problems with the pre-metric units. For example, Wikipedia says that by the time of the French Revolution, the existing system had become impractical for trade.

It doesn't say why it had become impractical, but my guess would be it had a lot to do with no good standard values for the units. If the units are not well defined in a way that gives the same values everywhere, it makes long distance trade harder.

I base this guess on doing some research once to figure out why they did not defined the meter to make conversion to Imperial easier. Since they were free to define the meter any way they wanted, they could have made 1 meter == 1 yard, which would have made conversions of long distances easier. Or they could have defined the millimeter as 1/25th of an inch, which would have made conversions of short distances easier than the 1/25.4th of an inch that we ended up with.

As far as I was able to determine, this was never an option because, as far as I could find, there was no widespread agreed definition of inches, feet, yards, etc. All that was standard was the relationships among them (1 foot == 12 inches, 3 feet == 1 yard, and so on).

There probably was no way to fix that without adopting a completely new unit, because if they tried to just make a new standard for, say, the yard I'm sure it would have gotten bogged down in arguing over whose yard to base it on. The French would think everyone should adopt their yard, the English would think everyone should adopt theirs, and so on.

So, a new unit, based on something not tied to any one region or nation, makes sense.

Temperature did not suffer from this, or did not suffer from it in a way that was not easily fixable. F was based on a reproducible physical 0 point based on the temperature of a brine with a self-stabilizing temperature. The only problem F had was that there had been some waffling over the other calibration point, which had been fixed well before the first attempts at a metric system.

So...why did they pick C?

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