Imperial versus metric

[Camacha]

First of all, I am not out to start a flamewar and this topic should not end up being one. I understand different people do things differently. It will always be like that and we should accept that.

I am very much used to the metric system. Most people will be aware that this is very structured, making conversions easier. For fun, I started doing problems in imperial units. Even though I have some idea of what each one should roughly indicate (inches from construction shows, feet from feet, yards from watching football and miles from car shows) I find it utterly impossible to work with the system in a somewhat intuitive and efficient manner. I understand that it is very much a matter of what you are used to, but I can truly not imagine anyone would want to work with something like that voluntarily. I found myself seriously wondering whether this does not regularly lead to conversion problems and all sorts of mistakes and construction problems. I can imagine that processing units in computer systems can be a bit of a hassle too. However, I am simply not used to the system, so maybe all this is not a problem at all.

I thought it might be interesting to share what your experiences with the different systems are I am very curious about the implications of day to day use to the imperial system. Any good stories about the origin or implementation of the systems are welcome too.

Edited December 30, 2013 by Camacha

[Themohawkninja]

It's really not that complicated, since you just memorize a few numbers and that's it. Hell, you could argue that you need more memorization for the metric system due to all the prefixes.

Here's an interesting question regarding these two systems that I would like to ask though. In America, why are things like gasoline and milk sold by the gallon, and yet soda is sold by the liter?

[Seret]

There's really not much to say in defence of the imperial system IMO. It's not used because it's better, it's used because it's perceived to be too much hassle to get rid of.

There's a big difference between systems of weights and measures for everyday use and for doing real work. It really doesn't much matter what units most folks use every day to measure distances and weights, imperial actually works perfectly well for this so they'll get little benefit from the effort and grief of switching. Where it's actually important to use a modern, coherent, logical system is in science and engineering.

Aviation is the only industry I've personally come across that actually uses imperial for real engineering, and that's because of the influence of some large US manufacturers. Do engineers working outside of aerospace in the US actually use imperial much? I take it actual science in the US is all SI, you'd be laughed at if you published anything in imperial, surely?

[Themohawkninja]

I take it actual science in the US is all SI, you'd be laughed at if you published anything in imperial, surely?

Oh, yes. I can attest to this. All science in America, as far as I know uses the metric system. All science courses teach it as well.

Whether or not you'd get laughed at... yeah maybe.

[Camacha]

It's really not that complicated, since you just memorize a few numbers and that's it. Hell, you could argue that you need more memorization for the metric system due to all the prefixes.

I am not sure I agree on the prefixes there, as the separate units in the imperial system are comparable. I guess it does not really matter whether you have to remember foot and inches or centi and kilo. It would also be good to realize that you only have to remember them once and that they are interchangeable and applicable to weight, distance, pressure and everything else. No separate prefixes or unit names for each of those.

kilogram = 1000 gram

kilometer = 1000 meter

versus

pound = 16 ounce

foot = 12 inches

Of course, the names themselves are a hint too, as cent stems from the Latin word centum for 100 Although I can imagine not everyone is aware of the Latin terms.

[Brotoro]

...I can truly not imagine anyone would want to work with something like that voluntarily...

You wouldn't be doing anything as absurd as using 60 minutes in an hour, 24 hours in a day, or 7 days in a week would you? My gosh...how do you survive?? And I'd hate to think how many radii fit around the circumference of your circles. Hopefully you've managed to make that come out to ten as well for peace of mind.

[Camacha]

There's a big difference between systems of weights and measures for everyday use and for doing real work. It really doesn't much matter what units most folks use every day to measure distances and weights, imperial actually works perfectly well for this so they'll get little benefit from the effort and grief of switching. Where it's actually important to use a modern, coherent, logical system is in science and engineering.

I just realized that there are still some premetric units unofficially in use here, alongside the official metric ones. In the market place they understand you if you order a pond or an ons, which not coincidentally sound very much like the English pound and ounce. They are somewhat metrified units, however, as they mean 500 and a 100 metric grams. You could order in grams or kilograms too; you would end up going home with the same thing in all situations.

The only situations I have seen those unformal units used is when it comes to food or personal weight loss. Metric is a lot more common though, it is a bit of a folkish thing.

[Camacha]

You wouldn't be doing anything as absurd as using 60 minutes in an hour, 24 hours in a day, or 7 days in a week would you? My gosh...how do you survive?? And I'd hate to think how many radii fit around the circumference of your circles. Hopefully you've managed to make that come out to ten as well for peace of mind.

To be honest, those can be a pain when you start to do some proper calculations with them. It would be interesting to explore why none of the more metric alternatives ever took off

And please, let us not make this a heated debate.

Edited December 30, 2013 by Camacha

[Seret]

You wouldn't be doing anything as absurd as using 60 minutes in an hour, 24 hours in a day, or 7 days in a week would you? My gosh...how do you survive??

Two wrongs don't make a right. You're quite correct that our units for tracking time suck.

And I'd hate to think how many radii fit around the circumference of your circles. Hopefully you've managed to make that come out to ten as well for peace of mind.

The advantage of the metric system isn't just that it's all base 10, it's that the various units all fit together nicely without requiring the use of horrific conversion factors. One joule per second is a watt, one newton per square metre is a pascal, etc, etc. It's a lovely simple system to work with. Do some serious calculations with it and I'm confident you'll quickly agree.

Your example of pi actually provides a good analogue. When doing anything serious you work in radians instead of degrees because it hugely simplifies your calculations. You could do everything in degrees, but your equations would be much more complicated. Why do it the hard way when a simpler, quicker alternative exists?

[Brotoro]

That wasn't heat. That was amusement.

[Seret]

I just realized that there are still some premetric units unofficially in use here, alongside the official metric ones.

Same where I grew up. Bizarrely it was normal to express your height in feet and inches and your weight in kilos. But that just goes to reinforce my earlier point: it doesn't much matter what system is in colloquial use, they're all pretty much fit for purpose if all you're doing is weighing bananas or dispensing beer. But if you're designing a nuclear reactor, you should probably be using something a bit more rational.

[Camacha]

Same where I grew up. Bizarrely it was normal to express your height in feet and inches and your weight in kilos. But that just goes to reinforce my earlier point: it doesn't much matter what system is in colloquial use, they're all pretty much fit for purpose if all you're doing is weighing bananas or dispensing beer. But if you're designing a nuclear reactor, you should probably be using something a bit more rational.

Well, there are some situations where it can be useful to be metric in daily life, such as liters being exactly 10x10x10 cm, or 1 kg in weight when it comes to that volume of water. But I guess you are right that in general it it not very important what you use, as long as you roughly agree to what the unit pertains.

Although I think it is striking that the local units here are metrified. Old nomenclature, new definitions, or something like that.

[SuperWeegee4000]

Sure, metric makes more sense, but sense is boring. That's why we call handegg football.

[Chrisd857]

I live in the US:

Imperial is the only system I have an intuitive sense with. My temperature is in Fahrenheit (close to 0 degrees today), driving distance is in miles, my height in feet and inches.

However, metric is the only one that is convenient in any kind of science/engineering problem, except if its all relative. For example, psi (or some variant like kilopound per square inch) is fine in a mechanics problem, because most everything there is just proportions. However, in a thermodynamics problem, Imperial is distasteful, and doesn't make sense to me.

So, Imperial for life, Metric for engineering.

[Camacha]

However, metric is the only one that is convenient in any kind of science/engineering problem, except if its all relative. For example, psi (or some variant like kilopound per square inch) is fine in a mechanics problem, because most everything there is just proportions. However, in a thermodynamics problem, Imperial is distasteful, and doesn't make sense to me.

So, Imperial for life, Metric for engineering.

Have you ever had any problems or mix-ups? I can imagine that reality checking something you just calculated can be less intuitive, or are metric units just as intuitive to you when it comes to those things? By reality checking I mean seeing that something you calculated does or does not make sense, such as a tower being 14 centimeters instead of 14 meters tall. I noticed it takes me considerably more effort in imperial units, as I need to reverse my calculations completely because the intuition is not really there.

Do you think you would have a lot of trouble adjusting if it were to be decided that everything is switched to metric?

Edited December 30, 2013 by Camacha

[DaveofDefeat]

Metric wins, U.S government tried to change over in the 1970's? Not to sure but its too expensive and people don't really feel like learning a new measurement system.

The united states uses customary units, which is slightly different from the British imperial units. bad op bad.

Edited December 30, 2013 by DaveofDefeat

[Dispatcher]

Countries in Red don't officially use the metric system:

[jwenting]

It's actually even worse, in that there are multiple definitions for the same thing in imperial.

A mile in one country is not the same number of meters for example as a mile in another country...

Same with "tea spoon", "cup", and other measures of volume.

And let's not get started about weights measured in "stones"...

[Nuke]

i prefer to use si units in all my code. when i build things i use imperial because all my tools are marked for it, id have to replace a few things. same goes for cooking measurements, i dont want to have to convert all the units in my recipe box, and i dont want to buy new metric measuring cups and spoons. some stuff is marked for both, but if we went hard metric id have to replace a lot of stuff. that said id be happy to switch to metric but i doubt its gonna happen.

Edited December 30, 2013 by Nuke

[TheCanadianVendingMachine]

Metric - 0 Degrees Celcius = Freezing, 100 C = Boiling - 100 Degree Difference

Imperial - 32 Degrees Fahrenheit = Freezing, 212 F = Boiling - 180 degree difference

Kelvin - 273.15 Degrees Kelvin = Freezing, 373.15 K = Boiling - 100 degree difference

By this, metric makes more sense, to, sensible people.

(All measures are based on water)

[Scotius]

Old habits refuse to die everywhere. Despite living with metric system all his life, my grandfather stubbornly measured nails and wooden elements in inches instead of centimeters. Just because. My grandmother purchased eggs in dozens, not tens. Et ceatera...

[Azivegu]

Well, I grew up in the states and then moved to the Netherlands, so I have had the best of both worlds. Because I want to be a creature of logic metric was the way to go for me. Whenever I am in the US on vacation, I usually try not to think about measurements too much, because that is when I start to get confused.

Also, as has been pointed out a few times, there are deviations between English and American measurements.

Try looking up the differences between UK and US here

[table=width: 500, align: center]

[tr]

[td][/td]

[td]UK[/td]

[td]US[/td]

[/tr]

[tr]

[td]Fluid ounce[/td]

[td]1[/td]

[td]0.96075994040*[/td]

[/tr]

[tr]

[td]Pint[/td]

[td]20 fl oz[/td]

[td]19.2151988081 fl oz*[/td]

[/tr]

[tr]

[td]Quart[/td]

[td]40 imp fl oz[/td]

[td]38.4303976162 US fl oz*[/td]

[/tr]

[tr]

[td]Gallon[/td]

[td]160 imp fl oz[/td]

[td]153.721590465 US fl oz*[/td]

[/tr]

[tr]

[td]dram (Avoirdupois system)[/td]

[td]1.772 g[/td]

[td]1.772 g[/td]

[/tr]

[tr]

[td]ounce(Avoirdupois system)[/td]

[td]28.35 g[/td]

[td]28.35 g[/td]

[/tr]

[tr]

[td]pound(Avoirdupois system)[/td]

[td]453.6 g[/td]

[td]453.6 g[/td]

[/tr]

[tr]

[td]quarter(Avoirdupois system)[/td]

[td]12.70 kg[/td]

[td]11.34 kg[/td]

[/tr]

[tr]

[td]hundredweight(Avoirdupois system)[/td]

[td]50.80 kg[/td]

[td]45.36 kg[/td]

[/tr]

[tr]

[td]ton(Avoirdupois system)[/td]

[td]1,016 kg (also known as long ton)[/td]

[td]907.2 kg (also known as short ton)[/td]

[/tr]

[tr]

[td]pint (Apothecaries' system)[/td]

[td]568 ml[/td]

[td]473 ml (in US noted as 'liquid pint'[/td]

[/tr]

[tr]

[td]fl ounce[/td]

[td]28.4 ml[/td]

[td]29.6 ml[/td]

[/tr]

[tr]

[td]fl. dram[/td]

[td]3.55 ml[/td]

[td]3.70 ml[/td]

[/tr]

[tr]

[td]fl. scruple[/td]

[td]1.18 ml[/td]

[td]1.23 ml[/td]

[/tr]

[tr]

[td]minim[/td]

[td]0.059 ml[/td]

[td]0.062 ml[/td]

[/tr]

[/table]

*: note that there are variations between normal 'fl oz' and 'food fl oz.'

I could go on, but I think the point is clear. To whoever said that the imperial system is less confusing, because they don't look alike and therefore you have to remember all those prefixes, well I would advise that you check out all the measurements. It is one old cluster f*ck. Just look at feet for a second. You have the: International foot, US foot, Imperial foot and the pre-1959 foot (I kid you not.) Next to that we can also look at countries that use the foot in layman's language. That can vary anywhere from 274.1 mm to 349,2 mm. And I measured the 72 measurements they had on wikipedia.

Here is a neat little test. Your foot is 314.858 mm and my foot is 287.0 mm, but both are feet are 1 foot. Where do we live?

With the metric system you don't have to keep second guessing your values and converting this to that to there every 5 minutes. With the metric system, all you have to do is remember to use the right prefix. And if you are to lazy for that (and I most certainly am) you can just use x*10^y. That way you can keep the same prefix :-)

I understand (as I have been there) that if it is what you are used to, you don't want to change it. But I advise most people that still use imperial to try out metric at least once in daily life. You don't want to keep converting back to imperial, just keep with the metric and then you start to notice how easy it is. There are no 76 deviations of one measurement, just 1. And it is also nice that the lengths aren't based on arbitrary numbers. That they actually have meaning (or are in the process of obtaining one) that are based in physics and chemistry, making both subjects so much easier.

Edited December 30, 2013 by Azivegu

[Azivegu]

btw, has anybody ever noticed that mileage is a really weird unit?

km/l is really

1*10^3m/1*10^-3m³

=

10^3m/10^-3m³

=

10^6m

???

unit cancellation is weird...

Edited December 31, 2013 by Azivegu
fixed some values

[Nibb31]

You wouldn't be doing anything as absurd as using 60 minutes in an hour, 24 hours in a day, or 7 days in a week would you? My gosh...how do you survive?? And I'd hate to think how many radii fit around the circumference of your circles. Hopefully you've managed to make that come out to ten as well for peace of mind.

The French Revolution attempted to impose a rational calendar called the Republican Calendar. It was used officially for 12 years before being abandoned and it included decimal time with 10 hour days and 100 minutes per hour.

http://en.wikipedia.org/wiki/French_Republican_Calendar

[J.Random]

btw, has anybody ever noticed that mileage is a really weird unit?

km/l is really

1*10^3m/0.1*10^3m

=

10^3m/10^2m

=

10m/m

???

unit cancellation is weird...

Erm... what? 1l = 10^-3 m^3, not 0.1*10^3m