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The metric system of units is best !!!

The metric system of units is best !!!

The metric system of units is best !!!

(OP)
The old imperial system of units which we British discarded in favour of the SI ( metric ) system of units, was a total joke. In hindsight I can believe that we British invented such a stupid system, it could only have happened in Britain !. If someone was simple, and completely drunk, they couldn't come up with a more stupid system.
However I can't believe that you Americans are still using it !
I am old enough to have experienced both systems during my life, as we in Britain changed over to the metric system gradually from 1970 on, this change started with the change of our money, called decimalisation.
The last remnants of the old system are still being eroded away today, as we still measure petrol in gallons, beer in pints, and buy meat in pounds. But I suspect in another 10 years it will completely disappear. Although miles may never disappear !
Have there been any suggetions or moves within the US, to drop the ridiculous Imperial system and replace it, with the sensible, and logical metric system. A system that most of the world has been smart enough to have adopted ?

RE: The metric system of units is best !!!

Despite a big effort in the '70's, printing car speedometers with both mph and kph and selling soda in liters, the metric system has been a huge flop in the US.  Come to think about it, just about everything has both type of measurement on it.  How much does that cost?  The public doesn't want it and our government is generally afraid they won't get reelected if they impose something on us.  So I guess we'll continue to use both.  At least we report our stock market prices in dollars and cents now, instead of eighths.

Blacksmith

RE: The metric system of units is best !!!

Much of the U.S. Transportation system (specifically the individual state Depts. of Transp.) were all heading toward the metric system in all their highway and bridge plans.

Now, many of them are actually retreating back to the "English" system.  The GSA (General Services Administration) that is in charge of most Federal building projects, the Corps of Engineers, and many other Fed. agencies are still using metric.

The problem in the U.S. is that it is so embedded in our culture that changing over will be a long, drawn out process....maybe taking decades.  Simply mandating it is very difficult.

The reinforcing bar manufacturers have actually sidestepped the process by creating "metric" rebar that is actually the original "English" sizes, just with metric names.

Personnally, I really don't care which way we go, as long as I have access to the same materials, specifications, data sheets, building codes, design guides, etc. in metric format.  Many participants in the building industry have moved this way (expansion anchors, metal decking, steel joists, etc.) but many have not.

Finally, the other concern I have (personally) is the loss of that "gut feeling" you get in design when you just know that a 1/2" thick plate isn't adequate and your calculations prove you right.  With metric, I would need some time to adjust and re-acquire that "gut feeling" about my designs and that period of time scares me a bit.

RE: The metric system of units is best !!!

Actually,  the US has been trying for quite a while to convert to metric.  However,  it is not an easy conversion.   For business,  it is expensive.  For individuals,  such conversions are always confusing and take some time to digest.   That, I'm willing to bet,  is why you're still in the process of converting in Britain.

The US government and many US companies are trying to convert.  A major part of the reason why the US hasn't successfully implemented wide-scale conversion yet is very simple to understand.   The US is very large.   To put it simply,  the larger the country,  the more difficult the conversion  ( both physically, mentally and monetarily ).   To date,  most businesses haven't had sufficient "monetary" reasons to seriously consider spending more money on converting.   And,  as we all know...  it is ALWAYS about money ( don't believe anyone who says otherwise ).

Note however, that the conversion process IS TAKING PLACE here.  It is just very gradual.  I believe our auto industry has converted as have several other industries.  I work with the California Dept of Transportation.  We converted several years back.   Our problem here is that most of our design manuals and software are still in Imperial units. .  Thus...  we do a lot of our work in Imperial and convert over.   Though doing it this way is a pain in the butt...  I think it has some advanatages.  It allows us to get a gradual feel for the different unit system.   Additional,  most of the contractors who build the bridges we design wish we were using the imperial units they are more familiar with

I for one will be happy when we are fully metricated here.

Dan   
www.dtware.com

RE: The metric system of units is best !!!

(OP)
JAE, that was interesting.
Don't worry about gut feel, you would eventually adjust.
Actually apart from the logicality of having units counting in tens, hundreds e.t.c., the metric system has another big advantage over the Imperial system :-
The inter-relation between the different units, i.e. How much does a 1m3 of steel weigh ?
Well 1m3 of water weighs 1Te, the specific gravity of steel is 7.65, therefore 1m3 of steel weighs 7.65Te.
You can not do this with the Imperial system !!!!!

RE: The metric system of units is best !!!

I do remember reading somewhere about the history and concept behind the Imperial vs. metric systems.  I don't mean to open a can of worms, but this particular article spoke of the "source" of the metric system as coming out of socialistic/marxist concepts of "man is a machine" while the Imperial units were derived from a more humanistic view of life - the inches, pounds, feet, etc. were derived from the human body.

It was quite philosophical and interesting for the history....but the application and use today of metric, I'm sure, doesn't mean squat to a marxist.  Or does it?

RE: The metric system of units is best !!!

(OP)
Please allow me to continue :-

Consider temperature, which is better Celcius, or Fahrenheit ?

Again for me there is no comparison.
What are the 2 most meaningful benchmarks of temperature in every day life, that we can all relate to ?
It has to be the boiling point, and freezing point of water.
We can observe these points every day, by boiling a kettle, and opening the freezer. Say the first point is 100, and the second is 0, and there you have it Celcius.
Now because Celcius is established on these 2 everyday benchmarks, it means that have a better feel for the magnitude of these units.

Yes the metric system is also beautiful, because of the inter-relation of the different units, and the benchmarking of the units.

RE: The metric system of units is best !!!

(OP)
JAE, do you know where the meter comes from ?

It was the ten millionth of the distance between Paris, and the North Pole, in otherwards there are 10,000km between them.
Whilst it would have been more useful if it was a fraction of the diameter of the Earth e.t.c., it doesn't alter the fact that it is still a practical benchmark.

RE: The metric system of units is best !!!

I think JAE's comment on how deeply ingrained some of the units are within our (US & UK) culture is very important. The Brits will NEVER give up there beloved pint of beer "568ml of best bitter, guv" just doesnt have the same ring.

The examples of miles, stones and especially feet and inches are particularly relevant. If you asked the average man on the street to describe another person they may say '6ft tall and weighing 14 stone'; if you described them as 1.82m and weighing 83kg, they wouldnt have a clue!

33 years after metric we still use miles and not kilometres for distances. Again try a small experiment on the street sof Britain and ask somebody how far it is to the nearest petrol station, the answer will be in miles. The reason is probably the expense, it will be even more expensive for a large country such as the US.

Units are arbitary anyway, an inch is only an inch because  somebody said it was and metric is essentially a political idea. The clue to the rise of Imperial measurements is in the name. Britain was the first country to industrialise and was more advanced in technology than any other nation on the planet at the time which, in turn, gave rise to the British empire. Then the measurement system of choice was the Imperial system. This was adopted by America and now it's her turn to be the most powerful nation on the planet - if they use Imperial (English) units you are not going to stop them.

Interesting subject that I'm sure will spark more debate, Bertboy.

RE: The metric system of units is best !!!

(OP)
AJUK, I agree with alot of your comments.
However, I dont think that just because we order pints in a pub, that this is necessarily an indication that the litre hasn't been successful.
I think the younger generation will start measuring peoples heights in meter, although I have to admit that I use feet and inches for peoples heights, however I use meters, for of all other heights. ( i.e. a useful reference dim that Engineers and Architects use for height, is that a door should be a min. height of 2.1m )
I do not use stones and pounds anymore to measure peoples weight, I definately use kilograms.
I think that the mile will be the most enduring unit in Britain, because it is still not under threat.

The reason why these remnants exist above is not because Imperial is considered better by some, and therefore there is resistance to change, it is more because the mothers and fathers, have indoctrinated the current younger generation, therefore there is bound to be a generation lag after the change.

RE: The metric system of units is best !!!

Bertyboy, An example to illustrate the problem comes from a general contractor bidding a parking structure in our town.  The final bid came in sveral hundred thousand dollars over the city estimate. The city required the plans use the metric system, which the contractor explained was the "fear" of the subcontractors unfamiliarity with this system.  Instead of seeing the typical 2x4's,W12x22,#6 rebar@12" o.c, 9 yards of concrete, 4x8 sheet of plywood, joists @ 16" o.c etc, etc(let alone the supply houses unfamiliarity with the system)the subs all admitted padding their bids. It will take some time, but eventually the U.S. will convert.  

RE: The metric system of units is best !!!

Bertboy:

I agree that the metric system is better for many calculations.  However two strong points:

(1) °F have much better correlation to everyday life in that 0°F and 100°F are linked to the temperature extremes that the human body can withstand.  The greater graduation lets me and my wife decide whether 73F or 74F is a better temperature for the thermostat (vs 22.77777C or 23.3333C)
(2) I think the British would be taken a little more seriously on the issue of which is a better system once they stop mixing the systems.  It is not uncommon for me to receive drawings for piping listed as 6" diameter by 4,200 mm long!

RE: The metric system of units is best !!!

As far as I'm aware the american imperial system is different from the british imperial system in some ways. One american pint of beer (if it exists now) is in fact 0.83 british pints. Getting short measures was probably the real reason for the american revolution, and who can blame them.
Seriously though, I always struggled over the poundal, pound force, and pound, especially as lb, alone, was commonly used throughout. At least with metric the units are distinct and we can be grateful that Newton, with his simple name, discovered it and not anyone else. Assessing a structure for a load of 1000 Albert Winterbottoms doesn't have the same ring to it as 1000 Newtons, somehow. Apologies to Albert.

RE: The metric system of units is best !!!

corus...are you suggesting we Yanks are, hic!, lushes?

RE: The metric system of units is best !!!

Wid tonge firmly planted in cheek...

Metric system is just for those lazy bums that don't want to divide by 12 and 4 and 3 and 7 and 62.4 and...

They just want to juggle the decimal point!

RE: The metric system of units is best !!!

Corus - what exactly are you saying that Newton (with his simple name), discovered ? He certainly didn't discover the "Newton", which was an unknown unit until the mid 20th century as far as I am aware.
JAE - The individual most responsible for the "Metric System" was clearly Napolean. This lunatic even tried to change the number of degrees in a right angle to 100. Because of it's factorability, counting in 12's actually makes much more sense than counting in tens, a fact which seems to have escaped N in spite of his much vaunted mathematical ability. Luckily it did not escape the Baylonians, who gave us 24 hours in a day and sixty minutes in an hour - to say nothing of 360 dgerees in a right angle. The Metric sytem is French, and should therefore be instinctively resisted by any red blooded person of British ancestry, on either side of the pond!

ps - you have to take the above with a grain of salt !

RE: The metric system of units is best !!!

Sorry - I meant 360 degrees in one revolution ! - so much for my mathematical ability !

RE: The metric system of units is best !!!

Here, here, EnglishMuffin.

(The channel is 21 MILES across, thankfully)

RE: The metric system of units is best !!!

EnglishM,
You're quite right, I meant to say that the unit of Force was named after Newton, and not Albert Winterbottom.

I'm not sure that Napoleon was responsible for the metric system though as being a small man he was just a 12 inch ruler, surely?

corus

RE: The metric system of units is best !!!

(OP)
Folks, listen to how stupid the units of length were :-
12 inches = 1 foot
3 feet = 1 yard
22 yards = 1 chain
10 chains = 1 furlong
8 furlongs = 1 mile
Now tell me that the person that came out with all that wasn't taking the p--- !

By the way the British Imperial system was not exactly the same as the US Imperial system. For example our gallon, and ton were not exactly the same as yours.
To differentiate this our sytem was called Imperial units, and yours was called US, or Customary units ( sometimes English ! ).
For example :-
1 Imperial gallon = 1.2 US gallons
1 Imperial ton = 2240 lbs ( called a long ton in the US )
1 US ton = 2000 lbs ( called a short ton in the US )


RE: The metric system of units is best !!!

Corus : that's a good one - sorry I misspelled "Napoleon" -just a typo. He did found the Ecole Polytechnique, I suppose, which gave us the bulk of the theory of elasticity. But then again, he himself wasn't actually French!

bertyboy : And what, pray, was so smart about defining the metre as one ten-millionth of the distance from the equator to the North Pole along a meridian passing close to Paris (where else)? Nobody could agree on what the distance was, so they ended up having to use a length standard very similar to the imperial master yard!

RE: The metric system of units is best !!!

Actually, having quoted all this stuff about Napoleon from memory, I decided to look up some web sites and found this one, which seems to contradict some of the things I said :

http://www.arvonia.net/~anti-metrics/fixed/USMA01/fixed.html

And on this site, they give a quote of Napoleon's :

"The scientists adopted the decimal system on the basis of the metre as unit. Nothing is more contrary to the organization of the mind, memory and imagination. The new system will be a stumbling block and source of difficulties for generations to come. It is just tormenting the people with trivia." - Napoleon Bonaparte

Nothing changes, does it ?

RE: The metric system of units is best !!!

We have to differentiate the SI system from the metric or thecnical   system. I agree complete in using the metric system, it is simple and easy to use, as many of you have pointed out. The  SI  system is not so simple and is not popular in Latin America, even  this countries  have adopted  it officially.

Just to organize my point: the SI uses a scientific concept: weight = mass x gravity, so Kg (force or weight) = Kg (mass) x 9.81 m/s2  = 9.81 N … therefore all the chain of the 10´s is lost, and to assimilate to “old units” we take   Kg(f)  =  +/- 10 N.

¡ All a confusion  to be understood for people that are not engineers!

There is a relation: 1 litre of water weights  1  Kg,  and   1 m3  =  1 T, which we lost with the N.

Imagine,  a dependant asking in a supermarket, how many   kN of meat a person wants! . .. I feel it is going to be very difficult that comun people assimilates and change  Kg   for  Newtons, and how EnglishMuffin suggests,...  aren´t   we in the middle of a contest?

Normally, we  make all the calculations and designs in metric, and if necessary,  write down afterwards in SI.

A similar discussion took place in thread                  507-59926,  “KIPS”.


RE: The metric system of units is best !!!

Unless you are running differing amounts of gravity in different stores, there is no need to use any other unit than a kilogram.  The kilogram is the SI unit.  SI is the metric system.  In fact, if you look at:

http://physics.nist.gov/cuu/Units/units.html

you can see that the accepted SI units DO NOT include Newtons, since that's dependent on g, which is not a constant.  The Newton is a derived unit, since it is technically a composite of 3 basic SI units.

Even our illegal drugs are bought in kilos

TTFN

RE: The metric system of units is best !!!

And in the USA even legal drugs and medicine are sold and administered in "cc", mL, mg. But the doctors/nurses still  determine body mass in lb's...maybe they measure in kg then convert to lb because most US patients do not know what a kg is!

RE: The metric system of units is best !!!

Most women I know would just LOVE  to convert to kilograms if someone would explain to them that their body weight "values" would be cut in half.

Dan   

RE: The metric system of units is best !!!

hernma: why would you want to price and/or buy meat in Newtons ? I suppose that would be an advantage for some future Moon dweller, since they would get about six times as much for their money.

IRstuff : What on earth are you talking about? The Newton unit has nothing whatsoever to do with the value of "g", and as far as I am aware was introduced specifically for the SI system in the mid 20th century.

RE: The metric system of units is best !!!

Sorry, must have been the illegal drugs throwing me off.

should have been something like:

you can see that the accepted SI units DO NOT include Newtons.  The Newton is a derived unit, since it is technically a composite of 3 basic SI units.

I'm not even sure where I was going with the g's comment.

TTFN

RE: The metric system of units is best !!!

Saaright! You know, I'm beginning to think that Napoleon was "right on" in that quote about 7 posts back! Before the French Revolution, the French system was even more confusing than the British system - virtually every major town had its own standards. But the new system got them even more confused, and Napoleon had to rescind it in 1812. It wasn't reinstated until about 1840.

RE: The metric system of units is best !!!

I was in Canada once , but as a tourist, so I didn’t have the opportunity of buying anything by weight, and I would be aware of the exception  , definition or synonymous  given in “SI unit rules and style conventions”:   “# 19: WEIGHT vs. MASS     When the word “weight” is used, the intended meaning is clear. (In science and technology, weight is a force, for which the SI units is the newton; in commerce and everyday use, weight is usually a synonym, for mass, for which the SI unit is the kilogram.)”

So, I  understand why my quotation of buying the meat in kN was hilarious to you; to me, what probes is only that my wife has reason when she says that every once  I go for shopping to the supermarket, all becomes a mess.

What… for the rest, my point remains: SI for commerce introduces a synonym for mass and weight (since the kg is a base unit of mass ---- ¿ doesn’t sound a little forced to you?).

But let’s talk about engineering: weight / area  is pressure, which in what I call metric system (with your permission IRstuff), weight is measured in T and area in m2, so very simple and direct (as in US units),  pressure = T/m2.

According to the reference given by IRstuff ( a very good one), in “Units outside the SI that are accepted for use with the  SI”, it is accepted the metric ton = 1000 kg. So that, in the case of pressure, the weight will be measured in T, the area in m2 , but the results have to be expressed Pa, MPa or N/m2.

I could go on and on and on, but it doesn’t worth, the idea is clear and  as said, my point remains : what  the newton  was invented for?

RE: The metric system of units is best !!!

For convenience.  

The same is true of the joule, which is kg-m^2/s^2 or watts, which is kg-m^2/s^3.  There is little intuitive recognition using the base units, unless you're one of those that can readily parse multiple units and powers in real time.  

Whereas, on the hand, a joule is immediately recognizable as a unit of energy and watt as a unit of power.  It's a shorthand, in the same vein as kilo, giga, etc.  The derived units allows one to conveniently express complex quantities simply, with having to resort to expressing a very commonly used unit as:

kg-m^2/s^3-A

Isn't volt much simpler and easier to understand and use?
As for the meat, that's a custom, more than anything to do with the units.  A kilo of beef is a piece of meat with a mass of 1 kilogram.  There's no need to involve anything to do with weight, except as a means of figuring out the mass.

TTFN

RE: The metric system of units is best !!!

IRstuff,

My understanding is
jule = N . m
watt = N. m/sec
N = m(mass) *g (graviational const)

If we follow this, the gravitational acceleration 'g' is inherent in the units you mention. But I am perplexed, that this comes from you.

You are Aero guy, so not hard for you to say that work done in far out space is much less than what we do here in our offices where g is high, and sometimes nerve breaking!

RE: The metric system of units is best !!!

Definition of newton is:
N=kg*m/s^2,

see same NIST link referenced above, about 1/2 way down the page.

Newton is the unit of force=mass*acc, NOT mass*g.

Joule is the unit of work=f*dist=kg*m^2/s^2=N*m
Watt is a the unit of power=J/s=kg*m^2/s^3=N*m/s

BUT, the point is that the newton is NOT a fundamental unit, it's a derived unit, conposed of other fundamental units.

Likewise joules, watts and volts are derived units.  

So if we were to use only "metric" units, we would be restricted from using newtons, joules, watts, volts, etc, since they are not fundamental metric units.

TTFN

RE: The metric system of units is best !!!

Thanks IRstuff for brushing off the confusion!

RE: The metric system of units is best !!!

For those interested - this has been discussed, too, in a thread with "KIP" in its title.  If I start a job in Imperial - I like to stay with it; if it is started in SI (not metric), I can stay with it.  It is a 'itch if you have to switch over in middle of job (i.e., at Syncrude tar sand mining in 1970s).  SI is okay but I find that, still, engineers can't agree on a common unit - I like kPa or MPa; others go for N/mm2; still others tonnes/m2.  I know it is typically factors of 10 - maybe even the same, but, let's pick kPa and stick with it for all pressures, eh?

Best to all - I'll be reading the thread again.  It is good to see all the different views - global views at that.

RE: The metric system of units is best !!!

The metric system makes perfect sense when you grow up with it.
In everyday life, you order a "half" (half litre) in the pub, you set the airconditioning to 23 or 24, you buy one kg of beef, etc.
We calculate everything with ton and m.

Calculating in SI is a little tricky. We are not used to using MPa and mm yet, but are slowly making the conversion. We always convert 1kg=10N. Nobody uses 1kg=9.8N.

RE: The metric system of units is best !!!

You mean 1kgf=10N (approximately). 1 kg = 1 N*s^2/m, as IRstuff correctly stated.
Trouble is, the kgf (or kilopond) is not an SI unit. This thread must have confused the hell out of people that don't know anything about SI units.

RE: The metric system of units is best !!!

Obviously, we're not learning from our mistakes.  Bad enough to have lbf, but we now have to contend with kgf?

Yecch...

The moral of the story is that convenience dictates the creation of new words and new units, which will simply mean that metric will get more and more non-metric baggage over time.

TTFN

RE: The metric system of units is best !!!

Why don't we just throw away the metric system and imperial and base all our computations on the "weight" and "volume" of a yard of ale!!!

RE: The metric system of units is best !!!

Let's go have some ale and discuss the matter further!!!!

Dan  
www.dtware.com

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