Metric vs Imperial

[ilikewaffles11]

Well, I typically use the Imperial system for MOST things however I wish I had been taught the Metric system as a kid. I needed to learn it for my auto tech class and find it incredibly simple. That being said whenever I think of measurement units I still use Imperial, I guess because that's what I've been using all my life.

 

[Famine]

Who needs Dr. Kawashima's Brain Training, eh?

Heh. It's just one of the things I like doing. I like nines because they make pretty numbers in decimal and they're easy to play with - you can third them without a fuss, you can half them with very little fuss and they're always within 10% of 10% of things. They're useful in Imperial conversions - nine litres is two gallons, nine pounds is four kilograms.

Love your nines!

 

[Grayfox]

Heh. It's just one of the things I like doing. I like nines because they make pretty numbers in decimal and they're easy to play with - you can third them without a fuss, you can half them with very little fuss and they're always within 10% of 10% of things. They're useful in Imperial conversions - nine litres is two gallons, nine pounds is four kilograms.

Love your nines!

Doctor Knickerbocker, Knickerbocker, number nine
He likes to dance and he keeps in time.

Also, your math is flawed.
2 UK gallons= 9.092L
2 US gallons=7.570L
8.818 pounds=4 KG

 

[Famine]

Also, your math is flawed.
2 UK gallons= 9.092L
2 US gallons=7.570L
8.818 pounds=4 KG

Like I just said, 2 gallons = 9 litres and 9 pounds = 4 kilograms. You're within 10% which is more than good enough (particularly if you remember that you're 10% under with mpg and 10% over with cooking times) for mental arithmetic like in the example I used above...

It's an easy conversion though. Two to nine - 2 gallons is 9 litres*. 40 litres is thus "nearly 9 gallons". I'd call it 8.8 in my head, then divide my mileage by 8 and lop ten percent off the result and round. 300 miles with 40 litres would be 34mpg (300/9 = 37.5, less 10% is 33.8, rounding to 34) - while the calculator says 34.1mpg.

Close enough.

 

[BobK]

The distance is actually 10,001,965m - any quadrant on a meridian is, Paris or otherwise.

Yep, like I said, they didn't quite get it right. They did pretty good for dawn-of-the-nineteenth-century technology, though. As for "through Paris", that's what they put in the spec. Unnecessary on a perfect sphere, but given that the earth isn't a perfect sphere, it was probably a good idea.

And it's an arbitrary division of an arbitrarily chosen location.

Oh agreed, but a whole heck of a lot better than "length of the king's foot" or "three barleycorns" or whatever. The idea was to devise a system that would be reproduceable (in theory anyway) without access to your local monarch whose foot size would change slightly over time not to mention might be completely different from his/her predecessor/successor's foot size.

Highly purified water is not easily available - seawater is, but it's not of an appropriate density to fill the volume with the right mass due to the impurities. And of course it's only pure water that's densest at 4 degrees - seawater isn't

Depending on what you're doing distilled water would likely be close enough. I could prepare a few milliliters/cc's/grams of distilled water in about 15 minutes or so, and I'm sure you could too. If you really need the accuracy of highly purified water then you'd go through the trouble/expense of obtaining same.

The metric system is nice and regular and all (save for the bits it can't be), but it's not of universal usefulness because it relies on arbitrarily chosen definitions - bits of planet, random substances, very irregular subdivisions of natural occurrences to fit in with our previous determinations - that make very little external sense...

And even then they only make sense in base 10 - which we've chosen because that's how many fingers we have and we only have that many because our evolutionary path included the pentadactyl limb... But at least we can explain that to an alien with our hands (assuming no amputees show up).The issue was probably that it'd require redefining all mathematics that underpins the sciences. We're kind stuck on a second being as long as it is because it's too tough to change.

Of course days are effectively as arbitrary - it's about how long this one rock takes to spin once (give or take a few seconds). Years too.Indeed - and radians too, at a pith of a circle (a radian is an arc [length of circumference] equal to the circle's radius).


I like Imperial, US Imperial and metric. They're all based on very oddly chosen things that have significance to our bodies or planet - one isn't better than another because it forgets this and goes in tens, nor is it worse because you can't cut things into threes all that easily.

But a proper universal measuring system should be based in fundamental dimensions - like the Planck length and time, the speed of light in a vacuum and the Gravitational Constant.

Perhaps we should overhaul our systems of measure but I really don't see it happening. I see no compelling reason to do so other than "it would be nice to..."; I suspect that any aliens intelligent enough to come visiting would be intelligent enough to handle something trivial such as unit conversions. Besides, they might find our system to be delightfully quaint.

As for binary arithmetic, I'd be perfectly fine with that. Actually I'd prefer hexadecimal, but it's trivial to convert hex to binary; I can do it as fast as I can write the digits. Binary to hex is only slightly more complicated as you either have to work right to left or count the digits beforehand and prepend leading zeroes as necessary to make the digit count a multiple of four.

At one point I was reasonably proficient at binary/hex arithmetic short of long division, and the types of problems that I could do in my head in decimal, I could also do in hex.

Except water's actually quite rare on the planet - it only exists in a thin layer on top of the crust, and nowhere else in the five thousand mile wide ball of iron-based rock.

While that's technically true, as a practical matter if you don't have any reasonably pure water available to you you'll be dead in a week which renders questions of accurate measurement pretty much moot.

 

[Liquid]

Oh agreed, but a whole heck of a lot better than "length of the king's foot" or "three barleycorns" or whatever. The idea was to devise a system that would be reproduceable (in theory anyway) without access to your local monarch whose foot size would change slightly over time not to mention might be completely different from his/her predecessor/successor's foot size.

Is this what North Americans are taught?

The foot has its origins in both Roman and Egyptian measurement systems, based on the average proportion of the average man. Granted, that's not the best foundation for a system of unit measurements, but it certainly wasn't from a measurement of a monarch's foot that changed with the passing of the crown.

Almost all measurements prior to at most the very late 18th century differed geographically. That is to say, it differed depending on where you were. The mile is a perfect example of this. It wasn't until I think the turn of the 17th century that the mile became standardised. In Britain at least, a London mile was different from a Birmingham mile. A Welsh mile was roughly equivalent to 4 modern miles, hence the phrase "by a country mile". (Wales is pretty rural for those not in the know).

The foot differed too, but as I said, not due to the succession of the monarchy. Napoleon wasn't small. He measured 5' 2", so naturally the English thought he must have been tiny. But he was 5 French feet and 2 inches. The French foot was longer than an English foot. In English feet, he would have been 5' 6", taller than the average at the time, and taller than the stumpy, 5' 4" Nelson. All of Britain's units of measurement were standardised with the Weights & Measurements Act 1824. Picture link.

And speaking of Napoleon, and traffic, it's because of him that we get driving on the right hand side. Obviously prior to the invention of the motor car there was a loose system of vaguely connected roads and paths in Europe. Etiquette was to ride one's horse on the left hand side because it enabled one's right hand to be free to wave or shake hands with someone, or indeed attack someone in the oncoming lane with a sword. Most people were right handed, so this made perfect sense. However, Napoleon was left handed, so in his conquering of Western Europe, he switched the direction of traffic so he himself could stab or wave to people without having to lean over.

Another quality we measure which was different geographically before standardisation was time. It was with the invention and expansion of the British railways that there was a need for consistent tellings of the time, so timetables could be accurate throughout the country, instead of contemporaneous 'local time'. "Railway time" was a Victorian term meaning absolute timely precision, and comes from this process of standardising time. That said, it wasn't until 1884 that an international meridian was formalised and the time zones as we know them were developed.

 

[kikie]

Who needs Dr. Kawashima's Brain Training, eh?

Heh. It's just one of the things I like doing. I like nines because they make pretty numbers in decimal and they're easy to play with - you can third them without a fuss, you can half them with very little fuss and they're always within 10% of 10% of things. They're useful in Imperial conversions - nine litres is two gallons, nine pounds is four kilograms.

Love your nines!

Going off topic.

Me too! . Probably the only thing we have in common.

 

[Jubby]

Personally I like to count everything in Planck units.

Remind me never to take road directions from you then, Famine.

Neither work together, and neither seem to be able to function in today's world without having the other as a complementary system.

It seems that we just need to start over and create a new system? Aren't we due for that every 300-400 years or so? I nominate Famine to start the creation, and we all can help!

 

[Johnnypenso]

Is it?

The king's foot doesn't change if you land on a different planet. You don't have to send surveyors 10,000km to check your king's foot and divide it into ten billionths. They're much of a muchness to me.Except water's actually quite rare on the planet - it only exists in a thin layer on top of the crust, and nowhere else in the five thousand mile wide ball of iron-based rock. Also it's not the water that's on the planet. It's a special kind where even one atom of something else throws the measurement out of whack. And it's at a temperature that isn't "normal" for the planet either (which averages about twelve Celsius).

As I said, I've got no real preference for either. They're both arbitrary in root definition and both have their flaws in the inability to scale easily in Imperial (is 20 inches one order of magnitude higher than 2 inches, or is 2 feet one order of magnitude higher?) and inability to third, sixth, seventh and ninth easily in metric.


Also I live in a country where we say how hot it is in Farenheit and how cold it is in Celsius.

Not sure where you live (your planet is 5000 miles wide, mine is a shade under 8000) but I live on the surface and 71% of the surface is water.
Metric just seems so simple to me as all measures are related to each other and everything is a multiple of 10. Even a monkey can do that math. I don't care if it's based on the length of a horse's 🤬, all I care about is how easy it is to work with.

Just as an aside, since I know the diameter of circumference of earth is exactly 40,000km I can figure out the diameter of earth with one simple calculation and come within a couple of hundred km's in my head and within a metre, given a minute and a piece of paper and pen. Try that with your king's foot...lol.

 

[Famine]

Not sure where you live (your planet is 5000 miles wide, mine is a shade under 8000)

No, my planet's core is. The iron-based rock bit? The mantle's mainly silicates.

but I live on the surface and 71% of the surface is water.

0% of which is purified water on which the measurement is based - and which, on average, runs three times higher temperatures (on your crazy decimal scale) than the one on which the measurement is based.

Metric just seems so simple to me as all measures are related to each other and everything is a multiple of 10. Even a monkey can do that math. I don't care if it's based on the length of a horse's 🤬, all I care about is how easy it is to work with.

The definition of a second isn't a multiple of ten (well, it is, but I assume you meant magnitudes of ten). Nor is the definition of a kilogram. Nor a metre. Nor a candela. Nor a Kelvin. Nor any of the SI units.

Decimal also hurts with thirding, sixthing, seventhing and ninthing, so it's not necessarily easier to work with - unless you only work with decimal scaling.

Just as an aside, since I know the diameter of circumference of earth is exactly 40,000km

I don't know where you live, but in my universe circumferences don't have diameters...

And the circumference of Earth isn't exactly anything. It's a mildly irregular oblate spheroid, so it has a minor-axis and a major-axis with their own circumferences. The shorter one - the meridional - is about 40,007km. The larger one - the equatorial - is about 40,075km, but there's a small amount of variability due to crust imperfections and gravitational influences.

I can figure out the diameter of earth with one simple calculation and come within a couple of hundred km's in my head and within a metre, given a minute and a piece of paper and pen. Try that with your king's foot...lol.

Kay then.

The circumference of the Earth at a meridian is approximately 24,865 miles. You'll notice that 24,865 isn't a multiple of three, but it's not far off (you're either dead on a three or one click either side - threes are good) - not far off enough that I can reach 8,300 in my head in an instant. Handily it's almost exactly a multiple of of pi - it's 8,020 x 3.1. I'd round down to 8,000 because of the subsequent figures of pi.

Looking it up, the smaller polar diameter of the Earth is 7,901mi (equatorial is 7,929). To within 100 miles in my head, without ever having to actually think, because threes. I could do 22/7 in my head too - seven 24,865s are 174,055 and 174,020 is 7,910 22s (or 15,820 11s) - to arrive at 7,911mi. Within 10 miles in my head, though it'd take a minute.

If you wanted it in feet, I'd just multiply the answer by 8 (miles to furlongs), 10 (furlongs to chains), 22 (chains to yards) and 3 (yards to feet) - 41,764,800ft.


Though I'll grant you I'm a bit of a synaesthete when it comes to moving numbers about. Your kilometreage may vary.

 

[Johnnypenso]

The circumference of the Earth at a meridian is approximately 24,865 miles. You'll notice that 24,865 isn't a multiple of three, but it's not far off (you're either dead on a three or one click either side - threes are good) - not far off enough that I can reach 8,300 in my head in an instant. Handily it's almost exactly a multiple of of pi - it's 8,020 x 3.1. I'd round down to 8,000 because of the subsequent figures of pi.

Looking it up, the smaller polar diameter of the Earth is 7,901mi (equatorial is 7,929). To within 100 miles in my head, without ever having to actually think, because threes. I could do 22/7 in my head too - seven 24,865s are 174,055 and 174,020 is 7,910 22s (or 15,820 11s) - to arrive at 7,911mi. Within 10 miles in my head, though it'd take a minute.

If you wanted it in feet, I'd just multiply the answer by 8 (miles to furlongs), 10 (furlongs to chains), 22 (chains to yards) and 3 (yards to feet) - 41,764,800ft.


Though I'll grant you I'm a bit of a synaesthete when it comes to moving numbers about. Your kilometreage may vary.

Sorry the example fails...lol. You started with the answer. I started with a metre...I know a metre is based on the circumference of the earth. You start with a foot...a king's foot...one foot...nothing else...go...lol

 

[Famine]

Sorry the example fails...lol. You started with the answer. I started with a metre...I know a metre is based on the circumference of the earth.

Uhh... I started with the circumference of the Earth - as you did - and got close to the diameter in my chosen units in my head in seconds.

That was the question you posed - get from the circumference to the diameter easily...

since I know the diameter of circumference of earth is exactly 40,000km I can figure out the diameter of earth with one simple calculation and come within a couple of hundred km's in my head

The circumference of the Earth at a meridian is approximately 24,865 miles. You'll notice that 24,865 isn't a multiple of three, but it's not far off (you're either dead on a three or one click either side - threes are good) - not far off enough that I can reach 8,300 in my head in an instant. Handily it's almost exactly a multiple of of pi - it's 8,020 x 3.1. I'd round down to 8,000 because of the subsequent figures of pi.

If you're going to demand I start off not knowing the meridional distance of the planet, you need to do the same - and since my unit was how they measured that distance in the first place and your unit was derived from those measurements, mine came first.

I need a unit and a stick to work out the circumference of the Earth in that unit. You need a unit, a stick, to work out the circumference of the Earth and then to divide that by a quarter (how decimal) and then by ten billion to generate a second unit to reach the circumference of the Earth in a second unit. I'm already doing two fewer calculations.

 

[MTC]

I don't know, I rather think it does. Removing all subjectivity from the equation* makes everything understandable from utterly raw, universal constants. An wholly objective measuring system. Makes me shiver like someone giving me a free Ford RS200.

I mean… we can't really get around the base problem unless it's shifted right to the simplest form of Base2. You don't even need to rely on aliens having fingers then – on/off state is the easiest thing in the universe to explain. But Base2 math is horrifying. I had to teach myself how to do mental arithmetic in binary and it actually hurt my brain.


Okay, so it's a bit of a tangent* and we might not meet them for a while yet, but it'll save vital seconds (Exaplancks?) of Richard Dreyfuss playing synth or Jack Nicholson Akking to get a line of communication going – and until then we have a completely objective way of measuring our universe.

*shivers again*


*MATHPUN!

It seems to me that even if you used a truly objective system, you wouldn’t have to work in binary all the time, you could use a system based entirely on base‐16*, and then convert to and from binary if and when you felt a need to. As long as you were used to base‐16 and/or binary maths (and you would be if everyone you interact with, even aliens, were using it), it’d be a lot easier than converting between metric and imperial, or between metric and either binary or base‐16.

*Why base‐16? Well first off you want to choose a base that’s easy to convert to binary, that basically means it has to be 2ⁿ. In pure binary (2¹) you’d end up working with long, unwieldy strings of ones and zeros, and base‐4 (2²) wouldn’t be much better. Base‐8 is a bit too arbitrary: 2³? Why 3, rather than a significant binary number? Base‐16 (2⁴ or 2^2^2) is about the right amount, not so high that you have too many different digits to work with, and not so low that your numbers end up too long and unwieldy.


As for the main topic of this thread… metric is just simpler than imperial, yes they are both arbitrary, but in metric everything is specifically interlinked, and easy to convert between. In imperial, it’s all over the place. 12 inches in a foot, 3 feet in a yard, 1760 yards in a mile… 14 or 16 pounds in a stone (I don’t even remember which, that’s how little I use imperial). Some people may be used to imperial and faster using it for mental arithmetic than they currently are with metric, but I can’t help thinking they’d be just as fast or faster with metric if they had used metric their whole lives.

 

[Famine]

It seems to me that even if you used a truly objective system, you wouldn’t have to work in binary all the time, you could use a system based entirely on base‐16*, and then convert to and from binary if and when you felt a need to. As long as you were used to base‐16 and/or binary maths (and you would be if everyone you interact with, even aliens, were using it), it’d be a lot easier than converting between metric and imperial, or between metric and either binary or base‐16.

*Why base‐16? Well first off you want to choose a base that’s easy to convert to binary, that basically means it has to be 2ⁿ. In pure binary (2¹) you’d end up working with long, unwieldy strings of ones and zeros, and base‐4 (2²) wouldn’t be much better. Base‐8 is a bit too arbitrary: 2³? Why 3, rather than a significant binary number? Base‐16 (2⁴ or 2^2^2) is about the right amount, not so high that you have too many different digits to work with, and not so low that your numbers end up too long and unwieldy.

The problem with anything other than binary is that you need to explain the numbers you're using - you need a system of translation. The Mesoamerican Calendar uses a variety of base12 and base16 units, but most Western folk would have no idea because their numerals bear no relation to our romanised ones. We''d struggle with Japanese numerals - they use base10 too - until what they write is explained to us in terms of what we write.

Binary uses on and off. You can explain every number in the system in seconds with anything you have to hand to any culture anywhere on the planet or otherwise without even knowing what numerals they use in their counting system.


While I would concede that you get to a painfully long string of numbers quite quickly, most folk don't really grasp numbers over a million anyway - you tell them the Earth is 93 million miles from the Sun, that the universe is 13.7 billion years old or that there's 6.2 x 10^23 molecules in a mole and you may as well be juggling eggs while shouting in Arapaho at them. There is little meaningful difference to them between 13700000000 and 1100110000100101010110100100000000 because either is stupidly long - and 14x10^9 is as meaningless as 11^10^10^10^10^10.

Numbers that people work with daily - stuff of a fourth order or less - are limited to 10 digits.

 

[W3H5]

This is the look on my face after reading this thread. Thanks Famine and Co. for baffling the bejesus out of me.

 

[Grayfox]

My mind in a way bluescreens when I read all that purple math text.

 

[monoha]

For subdivisions of a circle I have come across the "gradian" which is 1/400th of a circle. I've never seen grads in actual use, though; the only place I've ever encountered them is a "grads" button on scientific calculators next to the degrees and radians buttons.

A little bit late reply.
We, surveyors, use 1/400th degrees for a circle in our measurement instruments, we call the unit 'gon' - It isn't reeeally used today, since you don't sit and calculate positions from the measurements of angles/distance manually, but is the base of the behind calculations and index for the horizontical and vertical angles in the readings and physical part of the instrument. We loved those calculators with 'gradian' setting option back in the day!

Edit:
About the above discussion on the diameter and circumference of earth, we surveyors and mapmakers (does anyone call it that?), have a bit of a complex system to measure, reference and map the earth, which in my opinion matters in that discussion. If you guys are interested you could read about the concept lightly;
The geoid is a model of the gravitaional surface of earth (quite irregular, but of couse, close to a ellipsoid), which we use to determine hight (Z) measurements - note there are many local and some global customized versions of the geoid. Then there is a simpler concept, the reference ellipsoid, which is a approximation of the surface of earth (which I think Famine was referencing to with the two diameters?). That one is used for determining the plane coordinates (X and Y), also here, there are different versions. This is just a small part of the field of geodesy.