Metric/imperial

[Kertech]

"liquid"

I'm loving this, try typing p i s s 

[Tex_NL]

1 minute ago, Kerbart said:

Of course, the imperial system has very well defined units as well, these days. The inch, for instance, is defined as 2.54 cm

That doesn't change imperial is a weird and illogical system.

Answer quickly, which bigger: 7/16 or 4/9?
Errrr??? What? Let me think for a minute.

Answer quickly again, which is bigger: 0,4375 or 0,4444?
0,4444 obviously

7/16 = 0,4375
4/9 = 0,4444
Which of the two questions was easiest to answer?

[GDJ]

11 minutes ago, Tex_NL said:

That doesn't change imperial is a weird and illogical system.

Answer quickly, which bigger: 7/16 or 4/9?
Errrr??? What? Let me think for a minute.

Answer quickly again, which is bigger: 0,4375 or 0,4444?
0,4444 obviously

7/16 = 0,4375
4/9 = 0,4444
Which of the two questions was easiest to answer?

Well, being a Heavy Truck Technician for a number of years, I've learnt a few things:

7/16" = 11mm
1/2" = 13mm
9/16 = a snug 14mm
11/16 = a sloppy 18mm
3/4" = 19mm
1" = 25mm
1 1/4" = 32mm

Those are the common socket and wrench sizes. If you remember those, you can buy a few less tools.
 

Edited February 17, 2016 by GDJ

[sevenperforce]

4 hours ago, Tex_NL said:

It probably all comes down to what you've been thought as a child but what you're saying is exactly the opposite of what most believe. Imperial is has no logic. In science an technology metric is king.

As previously mentioned, Imperial has quite excellent logic; it's all based on factoring by prime numbers. Really useful in a pre-industrial or trans-industrial feudal/quasi-capitalist society where bargaining and bartering must be done without the aid of a calculator.

• Length: 2x2x3 inches per foot, 2x3x11 feet per chain, 2x5 chains per furlong, 2x2x2x3 furlongs per league.
• Area: 2x2x2x5 perches per rood, 2x2 roods per acre, 1 acre = 1 furlong x 1 chain.
• Volume: 5 ounces per gill, 2x2 gills per pint, 2 pints per quart, 2x2 quarts per gallon, 2 gallons per peck, 2x2 pecks per bushel.
• Weight: 2x2x2x2 ounces per pound, 2x7 pounds per stone, 2x2x2 stones per hundredweight, 2x2x5 hundredweight per ton.

All the largest units are made up of so many prime factors that you can just divide and divide endlessly without having to worry about running into fractions and long division.

[adsii1970]

9 minutes ago, Tex_NL said:

That doesn't change imperial is a weird and illogical system.

Answer quickly, which bigger: 7/16 or 4/9?
Errrr??? What? Let me think for a minute.

Answer quickly again, which is bigger: 0,4375 or 0,4444?
0,4444 obviously

7/16 = 0,4375
4/9 = 0,4444
Which of the two questions was easiest to answer?

Ok, wait... using fractions or decimals is NOT simply a function of the Metric verses Imperial system. It is based on nothing more than usage and the industrial period. Even in 19th Century United States, most people knew that 1/4 a pound and .25 of a pound were the same thing, just a different way of writing it. As the demand for machinery grew, so did the ways used to create the materials to produce the elements of industry - nuts and bolts, which were measured and accommodated with the use of fractions - a very common mathematical descriptor of those times as well as today.

4/9ths would be larger, using your example, because it is just shy of being a half (4.5 would be the actual half, and I came to that answer using mathematics!) also, 1/9th is smaller than 1/7th, meaning that there would be more "units" in the 4/9ths than in the 7/16ths... again, it is simply a function of mathematics.

Nice try, but I do have to call this out as a straw man argument. I could say that an inch is simply 1/12 of a foot or 0.083 of a foot, same basic measurement, just that it is written in a different style of notation. I could also say that 1 cm is simply 1/100th of a meter, and just because I have changed the decimal to a fraction doesn't mean I have now "Imerialized" the metric system. It is simply knowing about how to read fractions and their equivalent decimal number.

Edited February 17, 2016 by adsii1970

[p1t1o]

7 minutes ago, adsii1970 said:

Nice try, but I do have to call this out as a straw man argument. I could say that an inch is simply 1/12 of a foot or 0.083 of a foot, same basic measurement, just that it is written in a different style of notation. I could also say that 1 cm is simply 1/100th of a meter, and just because I have changed the decimal to a fraction doesn't mean I have now "Imerialized" the metric system. It is simply knowing about how to read fractions and their equivalent decimal number.

Its not that Imperial uses fraction and a decimal system doesn't. Its the arbitrary "easiness" of the fractions involved.

In decimal systems its always 1/10 or some multiple of that, with common Imperial adjustments there are a lot of different ones that are not multiples of each other. Simple as that.

 

12 minutes ago, sevenperforce said:

As previously mentioned, Imperial has quite excellent logic; it's all based on factoring by prime numbers. Really useful in a pre-industrial or trans-industrial feudal/quasi-capitalist society where bargaining and bartering must be done without the aid of a calculator.

• Length: 2x2x3 inches per foot, 2x3x11 feet per chain, 2x5 chains per furlong, 2x2x2x3 furlongs per league.
• Area: 2x2x2x5 perches per rood, 2x2 roods per acre, 1 acre = 1 furlong x 1 chain.
• Volume: 5 ounces per gill, 2x2 gills per pint, 2 pints per quart, 2x2 quarts per gallon, 2 gallons per peck, 2x2 pecks per bushel.
• Weight: 2x2x2x2 ounces per pound, 2x7 pounds per stone, 2x2x2 stones per hundredweight, 2x2x5 hundredweight per ton.

All the largest units are made up of so many prime factors that you can just divide and divide endlessly without having to worry about running into fractions and long division.

I have never heard Imperial units being related to prime factors before, it seems more arbitrary than that to me, but I'll take your word for it.

I'm not seeing the utility though, for example, what is the volume (in "gils") of a cube 3 inches to a side? Because I can tell you off the top of my head that a cube 3 cm to a side is 0.027litres, and that wasn't easy just because I have grown up with the system, its easy because there a similar relationship between units of distance and volume. What is the relationship between inches and gills - from your table above, its not clear. In a decimal system, for distance, area and volume, you only need the definition of a single unit to work them all out. From your table, I need one definition per line.

 

[sevenperforce]

Besides, you can make the same sort of argument in reverse.

A drink recipe calls for two parts vodka, three parts gin, and half a part of dry vermouth. You know that after shaking with ice, the volume will increase by one fifth. The martini glass can hold six ounces (177.441 mL) of fluid. Do you want to use Imperial measures (teaspoons, tablespoons, ounces) or metric measures (1 mL, 10 mL, 100 mL)?

[p1t1o]

3 minutes ago, sevenperforce said:

Besides, you can make the same sort of argument in reverse.

A drink recipe calls for two parts vodka, three parts gin, and half a part of dry vermouth. You know that after shaking with ice, the volume will increase by one fifth. The martini glass can hold six ounces (177.441 mL) of fluid. Do you want to use Imperial measures (teaspoons, tablespoons, ounces) or metric measures (1 mL, 10 mL, 100 mL)?

Poor example, the recipe is given in dimensionless physical constants!

[Tex_NL]

7 minutes ago, p1t1o said:

Its not that Imperial uses fraction and a decimal system doesn't. Its the arbitrary "easiness" of the fractions involved.

In decimal systems its always 1/10 or some multiple of that, with common Imperial adjustments there are a lot of different ones that are not multiples of each other. Simple as that.

I don't think I could have said it better myself.

[sevenperforce]

1 hour ago, p1t1o said:

I have never heard Imperial units being related to prime factors before, it seems more arbitrary than that to me, but I'll take your word for it.

I'm not seeing the utility though, for example, what is the volume (in "gils") of a cube 3 inches to a side? Because I can tell you off the top of my head that a cube 3 cm to a side is 0.027litres, and that wasn't easy just because I have grown up with the system, its easy because there a similar relationship between units of distance and volume. What is the relationship between inches and gills - from your table above, its not clear. In a decimal system, for distance, area and volume, you only need the definition of a single unit to work them all out. From your table, I need one definition per line.

All Imperial units are "built" by successive multiplication by primes.

The pre-industrial British economy didn't have much reason to relate small units of length with small units of volume. They did, however, relate cubic inches to gallons; there are 3x7x11 = 231 cubic inches per gallon. So a 3" cube is 3x3x3/3x7x11 = ⁹/₇₇ parts of a gallon. A gallon is 2⁵ gills, so a 3" cube is 32 gills/gallon times ⁹/₇₇ gallons, or ²⁸⁸/₇₇ gills. That's the same as 3 ⁵⁷/₇₇ gills, which is almost exactly 3 ³/₄ gills or 3 gills and 3 ounces, and I did that in a few seconds without a calculator.

I can turn it around. Suppose a certain type of grain costs $3 per kilogram and masses 1.5 kilograms per liter, and your 5 liter bucket is half full. How much is the grain in your bucket worth? Kinda tricky in a pre-industrial society without a calculator. However, if you're working with comparable values but using pounds, shillings, pence, gallons, pints, and ounces, it's a good deal simpler.

 

Edited February 17, 2016 by sevenperforce

[Kerbart]

43 minutes ago, sevenperforce said:

Besides, you can make the same sort of argument in reverse.

A drink recipe calls for two parts vodka, three parts gin, and half a part of dry vermouth. You know that after shaking with ice, the volume will increase by one fifth. The martini glass can hold six ounces (177.441 mL) of fluid. Do you want to use Imperial measures (teaspoons, tablespoons, ounces) or metric measures (1 mL, 10 mL, 100 mL)?

Obviously it would be ill advised to switch measuring systems in the middle of a process. I hope that's the point you're making. Similarly, using Imperial measures, regardless of their prime number witchcraft, would not be very suitable when you have to distribute 2L of cola (a standard measure even in the US) over 7 cups (the number of kids you can fit in a Chevy Suburban). Neither exercise says anything regarding the usefulness of either system, and much of the ways measures are expressed in either culture is geared towards its use.

Yes, a mile is 5280 foot and it's remarkable practical that such a number can be divided by practically any integer,so it's easy to split a mile into six pieces of 880 foot. But it's easy to do in metric as well: "one sixth of a kilometer." Done. Most of the arguments why one system is "superior" over the other are based on "the way you do things" in the preferred system. "If you need less than 1/4 and more 1/8 you pick 3/16, doh" is a nobrainer for mechanics used to imperial measurements. But a metric mechanic wouldn't entertain such thoughts and simply look for something between 9mm and 11mm. Guess what! It's 10!

If you're used to Imperial you'll deal with measurements in a way that matches the imperial system. Metric seems insane, I guess.
If you're used to metric you'll deal with measurements in a way that matches the metric system. Imperial will seem insane.

Science is where the metric system shines because you don't have to deal with insanely arbitrary conversion factors. In daily life, the two lines above apply.

 

[Bill Phil]

3 hours ago, p1t1o said:

Of course its arbitrary! How could it not be? You could just as easily use those things you mentioned, turns out using caesium does the job pretty well though.

Come on now, now you're just being difficult.

Thats a HUGE assumption. Go away, re-derive some equation or other, using Imperial [or any other, for that matter] units, so that it comes back "simpler" and come back with it and you will find that you will get FAR more support and be treated FAR more seriously.

I'm not even sure that the suggestion makes sense, but I'm OPEN MINDED...

 

But arbitrary is explicitly not natural. The only advantage metrix has is easy conversions, which doesn't apply to all units. Calories, why not just joules? Kelvin and Celsius? One of those is redundant.

[peadar1987]

1 hour ago, sevenperforce said:

As previously mentioned, Imperial has quite excellent logic; it's all based on factoring by prime numbers. Really useful in a pre-industrial or trans-industrial feudal/quasi-capitalist society where bargaining and bartering must be done without the aid of a calculator.

• Length: 2x2x3 inches per foot, 2x3x11 feet per chain, 2x5 chains per furlong, 2x2x2x3 furlongs per league.
• Area: 2x2x2x5 perches per rood, 2x2 roods per acre, 1 acre = 1 furlong x 1 chain.
• Volume: 5 ounces per gill, 2x2 gills per pint, 2 pints per quart, 2x2 quarts per gallon, 2 gallons per peck, 2x2 pecks per bushel.
• Weight: 2x2x2x2 ounces per pound, 2x7 pounds per stone, 2x2x2 stones per hundredweight, 2x2x5 hundredweight per ton.

All the largest units are made up of so many prime factors that you can just divide and divide endlessly without having to worry about running into fractions and long division.

Em, any number can be expressed as the product of primes. 2x2x5x5 centimetres in a metre, and so on. This isn't really a great argument.

4 hours ago, Darnok said:

For counting we have 10-based system. I said in one post that 10-based system is mainly for every day common use. While you are trying to convert equation made for 10-based system into other numeric systems... that is plain wrong. For different (for example) non-integer base system you would need different equations. But narrow mind is narrow mind, what you read in school stays true for you forever.

You would need horrendously complicated equations. Have you had any formal maths education? Do you have any idea how much of a mess randomly changing to different bases would be? If you use base pi for geometry, what do you use as your base for electromagnetics? What base do you switch to for things like the torque of an electric motor, which combines the two areas? It's nonsensical.

[sevenperforce]

1 hour ago, p1t1o said:

1 hour ago, sevenperforce said:

Besides, you can make the same sort of argument in reverse.

A drink recipe calls for two parts vodka, three parts gin, and half a part of dry vermouth. You know that after shaking with ice, the volume will increase by one fifth. The martini glass can hold six ounces (177.441 mL) of fluid. Do you want to use Imperial measures (teaspoons, tablespoons, ounces) or metric measures (1 mL, 10 mL, 100 mL)?

Poor example, the recipe is given in dimensionless physical constants!

Well, dimensionless ratios are the gold standard for comparing different units of measure.

10 minutes ago, Kerbart said:

Using Imperial measures, regardless of their prime number witchcraft, would not be very suitable when you have to distribute 2L of cola (a standard measure even in the US) over 7 cups (the number of kids you can fit in a Chevy Suburban). Neither exercise says anything regarding the usefulness of either system, and much of the ways measures are expressed in either culture is geared towards its use.

If you're used to Imperial you'll deal with measurements in a way that matches the imperial system. Metric seems insane, I guess.
If you're used to metric you'll deal with measurements in a way that matches the metric system. Imperial will seem insane.

I would argue that it's a little different. If you deal with measurements in a way that requires you to multiply and divide by simple integers on a regular basis, the Imperial system will usually be easier. If you deal with measurements in a way that requires you to move between orders of magnitude on a regular basis, the metric system will usually be easier.

I prefer the metric system because I do the latter more often than I do the former. But I can recognize the utility of the Imperial system for the former practice.

7 minutes ago, peadar1987 said:

Em, any number can be expressed as the product of primes. 2x2x5x5 centimetres in a metre, and so on. This isn't really a great argument.

Well, no. All metric units are divisible by 2 or 5 or 10ⁿ, but that's it. You're screwed if you need to divide by any other prime. A meterstick marked in 10-cm increments can be divided into halves, fifths, or tenths; a yardstick marked in inches can be divided into halves, thirds, quarters, sixths, ninths, or twelfths. Granted, a meterstick divided into individual cm gives you a little more flexibility, but not much more.

 

Edited February 17, 2016 by sevenperforce

[p1t1o]

8 minutes ago, Bill Phil said:

But arbitrary is explicitly not natural. The only advantage metrix has is easy conversions, which doesn't apply to all units. Calories, why not just joules? Kelvin and Celsius? One of those is redundant.

Yeah I might have got the definition of "natural unit" wrong on that one. I took it to mean "based on something physical you measured" but it's more irreducible than that.

That given, easy conversion is one big-a** advantage.

[sevenperforce]

1 minute ago, p1t1o said:

Yeah I might have got the definition of "natural unit" wrong on that one. I took it to mean "based on something physical you measured" but it's more irreducible than that.

That given, easy conversion is one big-a** advantage.

Yeah, it all comes down to conversion.

Do you need to convert on an order-of-magnitude scale, or do you need to convert on a single-digit-integer scale? If the former, use metric; if the latter, use imperial.

[mikegarrison]

By the way, I read quite a good book about the original expedition to measure the meter. I believe it was this book: http://www.amazon.com/The-Measure-All-Things-Transformed/dp/0743216768

Anyway, it's a fascinating story for many reasons. But one of those reasons is that the key here is not so much which units you choose, but that they be standardized. The real impetus behind the invention of the metric system was not so that the units would be better, but so that they would be uniform. Back in the day, a yard or a stone or a gallon or a meter were whatever they were in the locality you were at. One town's yard might be different than the next town's. The important thing was to make a uniform measurement system. Decimalizing it was really an afterthought, part of what can be considered a fad for decimalization in the aftermath of the French Revolution.

It was also a fascinating book because the ethos of the time was that science was perfect, and any measurement error was a terrible fault by a scientist. When one of the key leaders of the measurement expedition realized he had made a surveying error that he couldn't go back and fix, he was paralyzed with self-doubt and recrimination and basically stopped all work on the project for years while he remained in self-imposed exile from returning home to Paris.

Within a decade or so the concept swept the scientific world that all measurements include error and that a good scientist reports error rather than pretends to have eliminated it. But it was a little too late for Mechain (the man who had made the error).

[WestAir]

The thing I like about using the imperial system is I get a little more precision out of it because the numbers are usually larger. 3,000 meters is about 10,000 feet. With feet that gives you around 200% more quanta to express any given value. The same for temperature: The range from body temp to freezing in C s 37 to 0 (37 units), or in F it's 98 to 32 (66 units). It's not as simple to remember, but you get more precision.

Signed,

Devils Advocate.

[Tex_NL]

11 minutes ago, WestAir said:

The thing I like about using the imperial system is I get a little more precision out of it because the numbers are usually larger. 3,000 meters is about 10,000 feet. With feet that gives you around 200% more quanta to express any given value.

Why use 3.000 metres when you can use 3.000.000 millimetres? Now suddenly metric is more accurate.
Sorry buddy but that balloon won't fly.

[mikegarrison]

It was also ironic that before the French set out to accurately measure the true meter (one ten-millionth of the distance from the equator to the North Pole) they made a guess at what it would be. The estimated meter is now known to have been more accurate relative to the original definition than the final, official measured meter.

[GDJ]

3 minutes ago, Tex_NL said:

Why use 3.000 metres when you can use 3.000.000 millimetres? Now suddenly metric is more accurate.
Sorry buddy but that balloon won't fly.

I don't know about you but I certainly wouldn't answer any question regarding any large amount of distance between two points in millimetres or any number that is derivative or based on 1/16" (which is about the same).

Yeah.....no. Metres is fine for large distances, as are Feet. Would a pilot express altitude in millimetres or inches? No. They would use a unit of measure thats reasonable and easy to interpret. Would a Surveyor express distance between two points as strictly inches or Millimetres? No. They would use a unit of measure that's reasonable, THEN maybe add the Centimetres or Inches after the large unit for accuracy.

To use a figure of speech that you used.....your balloon is leaking.

[WestAir]

1 minute ago, Tex_NL said:

Why use 3.000 metres when you can use 3.000.000 millimetres? Now suddenly metric is more accurate.
Sorry buddy but that balloon won't fly.

Funny you say "that won't fly" because in the aviation industry, some countries use meters (Hint: not milimeters) for altitude while the rest of the world uses feet. It's safe to say that we get more precise altitude separation then them.

Do you have a retort for the extra precision using Fahrenheit temperature?

Disclaimer: This is tongue in cheek. I whole-hardheartedly expect your response to make us both laugh.

[AngelLestat]

Metric for scientific and imperial for mundane things --->  Wrong. 
Just use Metric for any case and you will save a lot of your time, in addition the world will save billions and billions of dollars.

Someone who knows Metric since kid; will do any measure or calculation faster than someone who learn imperial instead.
There is no case in where imperial is superior to metric.

Now the real question is:  how much it will cost for USA to change to the metric system..  I really don't care..  but they should do it..

The excuse time is over.
By the way..  enough advantage than the international language is english, so they don't need to waste 4 or 5 years learning another language, but only takes 1 day to learn the metric system.

[sevenperforce]

11 minutes ago, AngelLestat said:

Metric for scientific and imperial for mundane things --->  Wrong. 
Just use Metric for any case and you will save a lot of your time, in addition the world will save billions and billions of dollars.

Someone who knows Metric since kid; will do any measure or calculation faster than someone who learn imperial instead.
There is no case in where imperial is superior to metric.

Try baking without a scale, using volume measurements only for your ingredients.

[Tex_NL]

OK. Lets not use millimetres. Millimetres might have been a bit extreme, lets use kilometres and miles instead. You used 3.000 metres vs 10.000 feet, lets do 3,2 kilometres vs 2 miles. Suddenly metric gives you 120% 'more quanta to express any given value'
Your analogy is completely flawed and brings nothing useful to this discussion.