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

Re: International System of Units overhauled in historic vote

#381

Post by eadmund » Sat, Nov 17, 2018, 4:34 AM UTC

zmix wrote: post #366

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 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…

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.

Re: International System of Units overhauled in historic vote

#382

Post by thaumasiotes » Sat, Nov 17, 2018, 5:00 AM UTC

int_19h wrote: post #346

thaumasiotes wrote: post #229

Earlier quoted context omitted.

> Even for this SI overhaul, we didn't really even need to redefine the mole, except for the fact that it was previously defined in terms of the old kg. This was just "fixing a glitch". I came to complain about the article calling the mole a "base unit of the SI", and this seems like an appropriate thread. Why is the mole a defined unit at all? As far as I understand things, "one mole" is the same thing as Avogadro's…

The new definition of mole is exactly that - it's just 6.02214076×10^23 items of whatever, and no longer depends on kilogram.

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

Re: International System of Units overhauled in historic vote

#383

Post by gspetr » Sat, Nov 17, 2018, 5:12 AM 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:…

Excellent point.

100 -> 90 is 10% decrease.

212 -> 194 is ~8.5% decrease (and I had to go out of my way to count that).

Re: International System of Units overhauled in historic vote

#384

Post by aengvs » Sat, Nov 17, 2018, 5:14 AM UTC

kbenson wrote: post #357

jodrellblank wrote: post #333

Earlier quoted context omitted.

"It cannot perfectly represent the amount" you say, and then perfectly represent the amount. You represent a quarter as the fraction 25/100ths to show how impractical it is, instead of writing 1/4. Would it be so hard to build a ruler with thirds measured on it, so you don't need to try and guess 0.333333 from mm readings? Like http://teaching.monster.com/nfs/teaching/attachment_images/0... but made of metal

> "It cannot perfectly represent the amount" you say, and then perfectly represent the amount. Actually, I said "It cannot perfectly represent the amount (1/3)", so I specifically game an example immediately after the statement of exactly what I was talking about, which you then ignored and used an example for a different item to represent erroneously. What's up with that? > You represent a quarter as the fraction 25…

>No, I represent a quarter as 25/100's to show how it would be accurately represented in metric. 1/4 meter is not pure metric, it's applying a non-metric modifuer to a metric amount. The metric representation of 1/4 meters is 25 centimeters, which is 25/100.

What? Fractions aren't exclusive to the imperial system.

1/4 of a metre is metric, just as a 1/4 of an inch is imperial.

Everything below is a perfectly legitimate way of writing metric units:

1/4 m = 6/24 m = 3/12 m = 0.25 m = 25 cm = 250 mm

So easy!

Re: International System of Units overhauled in historic vote

#385

Post by bnjms » Sat, Nov 17, 2018, 5:18 AM UTC

mbroncano wrote: post #352

jawns wrote: post #306

Earlier quoted context omitted.

> irrational positions such as yours This is, frankly, insulting. You may disagree about the merits of blhack's arguments, but that doesn't make them illogical or unreasonable. It would be one thing if you said, "Here's why I think blhack has got it wrong, and why the arguments presented don't hold water." But you just tossed an insult without bothering to refute. Bad form.

I don’t think he got it wrong. I said he’s biased. I think you’re too.

And when he refuted the bias you claimed you dismissed him. Your every comment on this thread has been in bad faith and on at least one instance internally inconsistent. I’m sure you’re unaware but you’re uncharitable and not worth interacting with at any length.

Re: International System of Units overhauled in historic vote

#386

Post by gspetr » Sat, Nov 17, 2018, 5:26 AM UTC

combatentropy wrote: post #212

beloch wrote: post #206

Earlier quoted context omitted.

I like to commend my American friends for their undying loyalty to the memory of the Empire. U.S. customary units are derived from units that helped the British conquer the world, but even the British themselves have shamelessly abandoned them for the units of a filthy, monarch-less republic. It's good to see that Americans still subconsciously yearn for the firm ruling hand of their rightful Queen. Note: Americans h…

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."

In Russian you still have people using colloquialisms and idioms with units that were put out of use almost a century ago, yet everyone here gets the meaning (or at least the intent, which is what matters in the contexts they are used in) since they have stayed in the literature written centuries ago and of course nobody went out of their way to fix measurements in works of fiction.

Heck, most people using them don't even have a rough idea of how much they originally meant, and if you were to press them to give you a number for the sake of an experiment, they might be 2 orders of magnitude off.

https://en.wikipedia.org/Obsolete_Russian_units_of_measureme...

Re: International System of Units overhauled in historic vote

#387

Post by bnjms » Sat, Nov 17, 2018, 5:29 AM UTC

evil-olive wrote: post #372

bkanber wrote: post #328

Earlier quoted context omitted.

As an example, the common temperatures in NYC range from 0-100F. In celcius that's like -18 to +38. I'm a scientist and an engineer, and in those applications C is often better. But in daily life, Fahrenheit makes a ton of sense.

Just think about it by 10s, as you do with the metric system: 20 C - a bit less than room temperature (68 F) 30 C - pretty hot (86 F) 40 C - very hot (104 F) And going the other way: 10 C - a bit chilly (50 F) 0 C - cold (32 F) -10 C - real cold (14 F) -20 C - really really cold (-4 F) When you hear a temperature in Celsius, don't try to convert it to Fahrenheit, just think in Celsius. 15 degrees is halfway between "…

This is the right answer for Americans. The reason I prefer Fahrenheit is because it is the one I know what degrees feel like and because Celsius isn’t reported in enough resolution.

If it was always reported to the half point I think we would be able to relate to Celsius better. And if I was making a population wide change I’d ensure reporting was always to the half degree.

Re: International System of Units overhauled in historic vote

#388

Post by gspetr » Sat, Nov 17, 2018, 5:30 AM UTC

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).

I doubt that in practice an average person would be able to (reasonably) accurately differentiate between 4 miles and 5 miles or 6km and 8km without external measurement tools in an unfamiliar environment.

The heuristics at play that the human brain would use is likely: "5 miles is way more than I'd normally want to walk on my feet, since the trip would take me about 2 hours."

Re: International System of Units overhauled in historic vote

#389

Post by blhack » Sat, Nov 17, 2018, 5:47 AM UTC

csihar wrote: post #269

blhack wrote: post #259

Earlier quoted context omitted.

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.

What applications are you talking about? Just for a general example of the sort of thing I'm talking about: https://youtu.be/EWqThb9Z1jk?t=137

They're resurfacing a surface plate, which has to be very flat. If you listen to the exchanges between them, everything is being done in millionths of an inch.

Re: International System of Units overhauled in historic vote

#390

Post by MattRix » Sat, Nov 17, 2018, 5:49 AM 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…

F is not superior to C, your argument for it makes very little sense, even from a plain human "everyday" (non-scientific) point of view. Can anyone sense when the temperature changes by a single degree in F? I doubt it. With C you have a chance. With C when it's below zero you know there could be snow and ice.

Each set of 10 degrees in C is a pretty clear temperature range. 30-40 scorching. 20-30 hot. 10-20 warm. 0-10 cool. -10 to 0: cold