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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

#261

Post by cco »

ekimekim wrote: post #227
cco wrote: post #164

Earlier quoted context omitted.

That doesn't make sense to me, the definition has changed. The IPK was 1 kg and the copies of it were all slightly heavier or lighter, for argument let's say IPK1 was 1.1 kg and IPK2 was 0.9 kg. Now that we have a constant for the mass of 1 kg, all of those IPK's will now have a new mass relative to the new definition. Unless the new definition was based on the current IPK and set its mass as of today as the standard…

> Unless the new definition was based on the current IPK and set its mass as of today as the standard, and that standard now will be unchanging? Correct. The current IPK will still be 1kg to within margin of error at the time the new definition comes into effect, but any further changes to it will make it, for the first time, drift away from that value.

Ah I see, that makes sense, thanks!

Re: International System of Units overhauled in historic vote

#262

Post by deelowe »

devindotcom wrote: post #241
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 hadn't thought of some of these advantages. Some are subjective, but it's hard to deny the intuitive nature of others. I say bring back the span and the rod as well.

Go walk a job site with a tradesman and youll see why imperial is so useful and natural to them. They walk off long distancrs, use knuckles for small ones and do complex division with ease.

Re: International System of Units overhauled in historic vote

#263

Post by nicoburns »

slivym wrote: post #230
combatentropy wrote: post #212

Earlier quoted context omitted.

It just doesn't have the same ring to it. "He won't move an inch," or "He won't move a centimeter." "She won't quit until she's six feet under," or "She won't quit until she's two meters under." "I'll go the whole nine yards," or "I'll go the whole nine meters." "You can see for miles and miles," or "You can see for kilometers and kilometers."

I think there's a serious point to what you're saying. I was bought up in the UK so I have metres for short distances and miles for long distances. If you say to me 5 miles I instantly know what you mean. If you say 8km, I have an academic understanding but not really an intuitive feel for what you mean (other than 8km=5mi, feel 5mi).

That's just familiarity though. People in countries that primarily use kilometers have the same intuitions about them.

Re: International System of Units overhauled in historic vote

#264

Post by bdamm »

stass wrote: post #244
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…

What are the redeamable qualities of metric units?

They're globally standard, decimal, and internally consistent. One never needs to wonder how many meters in a kilometer or how many grams in a kilogram. They have some human usable qualities as well; it's convenient that water freezes at 0°C and that a kilogram of water is also a liter.

Re: International System of Units overhauled in historic vote

#265

Post by mbroncano »

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…

Most probably because you grew up with it. I’m pretty sure you think the same about your religion, nation, race ... but be sure eveybody else in the world may think the same of their own. And they’d be right too.

What I personally find disturbing is how irrational positions such as yours are commonly accepted in a supposedly advanced society. It leads to a pretty bumpy road, time and time again.

Re: International System of Units overhauled in historic vote

#266

Post by ape4 »

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 see you're not liking how many feet are in a mile (and many other silly things).

Re: International System of Units overhauled in historic vote

#267

Post by dfox »

Sharlin wrote: post #185
tbirrell wrote: post #160

Earlier quoted context omitted.

You could just define the second to be a 1/100,000 of a day and go from there. Aside from screwing with literally everyones perception of time, it could work.

But which day? Such a second would probably work for everyday purposes (just like to most of us a second is 1/86400 of a day) but it would be woefully inadequate as a universal fundamental unit of time. And defining the second in terms of something like "the length of the solar day at Greenwich meridian on Jan 1 2020" prevents anyone from ever reproducing the exact value based on their own measurements, which is one…

One can arbitrarily define a second as anything and then say that one UTC day usually has 100000 seconds and some are longer or shorter. It is just a matter of scaling few unit definition constants by 10000/86400.

Re: International System of Units overhauled in historic vote

#268

Post by hueving »

mbroncano wrote: post #265
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…

Most probably because you grew up with it. I’m pretty sure you think the same about your religion, nation, race ... but be sure eveybody else in the world may think the same of their own. And they’d be right too. What I personally find disturbing is how irrational positions such as yours are commonly accepted in a supposedly advanced society. It leads to a pretty bumpy road, time and time again.

There isn't anything more rational about demanding base 10 systems.

Re: International System of Units overhauled in historic vote

#269

Post by csihar »

blhack wrote: post #259
saagarjha wrote: post #248

Earlier quoted context omitted.

It’s based on the decimal system, which we happen to use in our primary numerical system as well?

We use the decimal system for imperial units too. Thousands of an inch, millionths of an inch, etc.

In most practical applications that I've seen fractions of imperial measurements used, it tends to be in powers of 2, i.e., 3/16 inch, 1/4 mile, etc. Decimals can certainly be used, but for most applications where you'd use something like a "millionth of an inch," it's vastly more common to use metric.

Re: International System of Units overhauled in historic vote

#270

Post by kderbyma »

gus_massa wrote: post #196
zamadatix wrote: post #102

Earlier quoted context omitted.

For your first question some Kibble balances have accuracy parts per billion in measurement of the kilogram. For your second question, agreed - no trade deals care about the accuracy of the new kilogram vs old.

I agree that nobody cares for this level of precision in comercial trade, but as a thought experiment ... According to the first result in Google https://brightside.me/wonder-curiosities/the-16-most-expensi... > 1. Antimatter — $62.5 trillion per gram > 2. Californium — $25-27 million per gram So the difference is a few dollars per milligram of antimatter, and less than a cent per kilogram of Californium. From https:…

Your math is off..... 62T / 1g = $62B /mg = $62M/ug.

$100 million dollar rounding error.....

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