Naked Science Forum

General Science => General Science => Topic started by: DiscoverDave on 13/11/2009 16:22:44

Title: Whatever happened to the metric system conversion in the United States?
Post by: DiscoverDave on 13/11/2009 16:22:44
When I was a kid in school, they told us the metric system was the future, and we had to memorize all sorts of excruciating conversion factors with tons of decimal places.  And then ... nothing. 

Has the United States abandoned its conversion?

Has it gotten bogged down in its bureaucracy?

Has it proven itself unfeasible?

What does the future hold?

What other countries haven't converted to it?
Title: Whatever happened to the metric system conversion in the United States?
Post by: daveshorts on 13/11/2009 17:31:00
I would have thought mostly got bogged down in general inertia and misplaced patriotism. A similar reason to why the UK is still not fully metricated. I know what 60mph is but 100kph is a little more fuzzy.

Is physics and engineering metricated yet? as the metric system makes far more sense when you are dealing with huge numbers and computers.

Bizzarely the US army metricated in the 19th century, long before the British army.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Geezer on 14/11/2009 06:03:15
I think it's a bit of a mess. Much of US industry is metric, but there are many old standards that are so well established they are really hard to eliminate. One solution is probably to "metricate" (wot an 'orrible word) those standards (without really changing them at all) and move on.

BTW, it would be really nice if the metric system could at least converge on one set of symbols for decimal points and thousands delimiters. Commas and periods seem to be interchangeable. It's very confusing, and I'm sure it has resulted in some major cock-ups.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Don_1 on 15/11/2009 11:14:22
I think the problem for the US would be the unbelievable cost of conversion.

As Dave said, the UK has not gone all the way yet and I think its not just a case of 'imperialism'. Yes we know our MPH far better than we know our KPH and might find it difficult to get our heads' around an 80kph speed limit instead of the 50mph limit we know & hate love. But it really shouldn't be too difficult if our speedo' is clearly marked in KPH. But imagine the cost to the individual of converting those speedos', so the prominent scale is the KPH. Now imagine the cost of changing all those road signs and the logistical problems. You couldn't do them all overnight. So which are KPH and which are MPH?

Then there are the signs telling me 'Birmingham 98' Is that 98 miles or kilometers?

Now consider the cost of replacing rulers, scales, volume measures etc etc AND the cost of educating the populous in those conversions.

Although the US would be better off converting, in the long run, it only has to look at the chaos and confusion it has caused, and continues to cause, in the transitional period in the UK, not to mention the imperialist backlash.

If the US do go ahead with metrication, it should learn from our mistake, do it quick and clean, don't draw it out over a long period.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Madidus_Scientia on 15/11/2009 12:11:48
I only use the imperial system when i'm at Subway and I ask for a foot-long sandwich :P
Title: Whatever happened to the metric system conversion in the United States?
Post by: Geezer on 15/11/2009 21:24:26
If the US do go ahead with metrication, it should learn from our mistake, do it quick and clean, don't draw it out over a long period.

It already has been dragging it out for years and years! In some parts of the country (NY State for example) you'll find speed limits posted in MPH and KPH.

BTW, my speedometer is marked in MPH and also in KPH. Don't they do that in the UK too? It would seem like a good idea for those who take their cars to Europe. Also, I can switch my oddometer between miles and kilometers and the economy meter is switchable too.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Don_1 on 16/11/2009 11:38:03
Our speedo's are marked in KPH as a secondary smaller scale on the analogue displays, but its not so plain as the MPH scale.

I don't know about all cars with digital displays, but almost all trucks are switchable between KPH & MPH.
Title: Whatever happened to the metric system conversion in the United States?
Post by: destron on 16/11/2009 16:45:16
I would love to see the US convert to the metric system but there are so many difficulties that it is only a slim possibility at this point. In particular, I have heard that the auto industry would have a terrible time retooling to work in a metric system. I also think there is no political will in the US to convert to metric because, for ignorant political extremists, conversion to the metric system would be deferring to the Europeans.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Geezer on 16/11/2009 21:45:03
In particular, I have heard that the auto industry would have a terrible time retooling to work in a metric system.

Then someone was winding you up. I can't find a fastener on my Dodge truck that is not metric! I think the US auto industry converted to the metric system quite a few years ago.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Nizzle on 17/11/2009 14:30:11
You couldn't do them all overnight.

It's possible. The UK should ask Sweden...

In Sweden, cars were driving on the left side of the road, and poof! The next day all traffic signs were changed and the cars were driving on the right side of the road like their neighboring countries.

Also: the metric system is way more scientific than the uk/us system.
Only thing I'd like to see changed is that two perpendicular lines should make a corner of 100 degrees, and not 90 degrees as it is now...
Title: Whatever happened to the metric system conversion in the United States?
Post by: Nizzle on 17/11/2009 14:30:47
You couldn't do them all overnight.

It's possible. The UK should ask Sweden...

In Sweden, cars were driving on the left side of the road, and poof! The next day all traffic signs were changed and the cars were driving on the right side of the road like their neighboring countries.

Also: the metric system is way more scientific than the uk/us system.
Only thing I'd like to see changed is that two perpendicular lines should make an angle of 100 degrees, and not 90 degrees as it is now...
Title: Whatever happened to the metric system conversion in the United States?
Post by: Geezer on 17/11/2009 16:31:37
The next day all traffic signs were changed and the cars were driving on the right side of the road like their neighboring countries.

If I remember correctly, nobody was allowed to drive for at least a day. Also, at that time, I don't think there were many, or even any, motorways/freeways/autoroutes in Sweden, so it was largely a case of switching all the signs around. The entrances and exits on motorways are not necessarily symmetrical, so it might require some significant reconstruction as well.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Bored chemist on 17/11/2009 18:35:06

Also: the metric system is way more scientific than the uk/us system.
Only thing I'd like to see changed is that two perpendicular lines should make a corner of 100 degrees, and not 90 degrees as it is now...

Why was the foot pound second system any less "scientific" than the metre kilogram second system?
and why do you want this
http://en.wikipedia.org/wiki/Grad_(angle)
 rather than the SI unit of angle ( i.e. the radian)
Title: Whatever happened to the metric system conversion in the United States?
Post by: Geezer on 17/11/2009 18:57:00

Also: the metric system is way more scientific than the uk/us system.
Only thing I'd like to see changed is that two perpendicular lines should make a corner of 100 degrees, and not 90 degrees as it is now...

Why was the foot pound second system any less "scientific" than the metre kilogram second system?
and why do you want this
http://en.wikipedia.org/wiki/Grad_(angle)
 rather than the SI unit of angle ( i.e. the radian)

Pay no attention BC. Nizzle can't tell his commas from his decimal points  [:D]

Furthermore, if SI actually did define a unit based on angle, I think there would have to be 1 per revolution, not 400. So a right angle would be 0.25G or 250mG (I assume it would be called the Geezer)
Title: Whatever happened to the metric system conversion in the United States?
Post by: Geezer on 20/11/2009 05:18:29
Where's the Spamish Inquisition when you need them? They are soooo unpredictable.

Update:  Thanks moderator! The Spamish post is no more.
Title: Whatever happened to the metric system conversion in the United States?
Post by: techmind on 20/11/2009 20:57:58
For the benefit of international readers...

In the UK we are fully metricated in schools (teaching metres, kilograms, Celcius etc.) - and have been for 30 years or more. In everyday life we seem to be metricated with the exception of pints (beer, and sometimes milk), miles/yards (road distances), and fuel economy which is miles-per-gallon despite the fact that petrol (gasoline) is sold in litres!

Pounds (weight) persisted in food-retailing for both greengroceries (and other loose produce) and jars (e.g. 1lb jars of jam/honey) until 5-10 years ago. For quite a while these have still been sold as 454g and suchlike, but I think gradually as packaging becomes redesigned, they will go properly metric.

Actually inches do still persist in clothes retailing - mens trousers still have waist-sizes and leg-lengths, and shirts have collar-sizes in inches as the principal unit of measure. This would be tricky to change, as you'd either need to stock more sizes to cover the range (if you went with smaller eg. 2cm steps) which the retailers won't like, or worse precision of fit (if you went with bigger steps) which the customers won't like.

Womens' clothing-sizes are a law of their own.

Shoe sizes really haven't been standardised internationally, or even so it seems between manufacturers! "9 for shoes, 10 for trainers" or similar. In UK sizes, the step between childrens' sizes is bigger than that between adult sizes, although childrens' shoes usually come in half-sizes whereas adults don't necessarily.

I think people still weigh themselves and think about their weight in pounds and stone (at least older people), although all bathroom scales have also shown kilograms for years.

Is rental of office/shop space in London still quoted in £/sq.ft or has that been updated now?

On the weather forecasts, temperatures are all Celcius - except for certain newspapers which use Farenheit (people over the age of 50 still profess not to understand Celcius). Pressures (although 'dumbed down' and rarely mentioned on the TV now) are always shown in millibars, and not Pascals (N/m2).


Of course we do have a serious issue with tools, which need to be sold using the units they actually are made-to, because in precision engineering the difference between the true imperial size and the metric 'equivalent' (to say 2 decimal places) really does matter when you're trying to make a press fit, or a screw thread or similar. A 3/16th inch drill would actually be 4.7625mm, which is different from "4.8mm" which you might see. For legacy reasons therefore, certain tools therefore need to be available (and, to avoid confusion, sold - despite the law) in both true-imperial and true-metric sizes.


(Be aware also that a US gallon -and pint- are smaller than their UK/Imperial namesakes.)

Apart from the national norms of pints/miles/mpg, I personally (age 34) think in metric for everything, but I'm bi-lingual with inches/feet and metres/centimetres and will (almost deliberately) mix my units for convenience when describing parts/sizes verbally and/or just because I can! "Ohh, about an inch long by 3mm thick", or I'll choose either "half a centimetre" or "a quarter of an inch" according to which is closer to the size I envisage in my mind.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Geezer on 20/11/2009 21:11:34
For the benefit of international readers...

In the UK we are fully metricated in schools (teaching metres, kilograms, etc.) - and have been for 30 years or more. In everyday life we seem to be metricated with the exception of pints (beer, and sometimes milk), miles/yards (road distances), and fuel economy which is miles-per-gallon despite the fact that petrol (gasoline) is sold in litres!

Pounds (weight) persisted in food-retailing for both greengroceries (and other loose produce) and jars (e.g. 1lb jars of jam/honey) until 5-10 years ago. For quite a while these have still been sold as 454g and suchlike, but I think gradually as packaging becomes redesigned, they will go properly metric.

Of course we do have a serious issue with tools, which need to be sold using the units they actually are, because in precision engineering the difference between the true imperial size and the metric 'equivalent' (to say 2 decimal places) really does matter when you're trying to make a press fit, or a screw thread or similar. A 3/16th inch drill would actually be 4.7625mm, which is different from "4.8mm" which you might see. For legacy reasons therefore, certain tools therefore need to be available (and, to avoid confusion, sold - despite the law) in both true-imperial and true-metric sizes.


(Be aware also that a US gallon -and pint- are smaller than their UK/Imperial namesakes.)

Not to mention that the fluid ounce is also different.

However, the UK does not appear to have adopted the common European practice of using commas as the decimal point and periods (full stops) as thousands delimiters. Is this not a potential source of great confusion?
Title: Whatever happened to the metric system conversion in the United States?
Post by: techmind on 20/11/2009 23:32:33
However, the UK does not appear to have adopted the common European practice of using commas as the decimal point and periods (full stops) as thousands delimiters. Is this not a potential source of great confusion?

It can be a little disconcerting, but mostly fairly obvious. There could be cases which are not 'obvious' from the context though.

India is a strange one: they seem to have a ten-thousands separator instead of a thousands-separator. I don't know whether they continue every 4 places for huge numbers or what.
Title: Whatever happened to the metric system conversion in the United States?
Post by: jerryfox004 on 24/11/2009 07:32:16
I also think there is no political will in the US to convert to metric because, for ignorant political extremists, conversion to the metric system would be deferring to the Europeans.
Title: Whatever happened to the metric system conversion in the United States?
Post by: Laura_Kelly on 24/11/2009 08:21:26
We've been metric in New Zealand for as long as I can remember (perhaps cause I'm a young'un), but it really doesn't cause issues. I suppose its easier for everyone, but as far as I know, it was a small upheaval because there are so few people compared with the US.
It does make it easier though - metric system for money ($), measurement and everything. The only thing we use inches for is measuring tyres and tv screens!
Over here, we don't use the imperial system and it can get blimmin frustrating when watching some American programs because we have know real appreciation of distances represented by feet and yards and miles etc...
Title: Whatever happened to the metric system conversion in the United States?
Post by: Geezer on 24/11/2009 17:14:30
My term paper is in Spamish.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: syhprum on 25/12/2017 07:41:34
The astromoners are the ones that really annoy me who talk about the output of supernovas in ergs and radiation in Angstroms
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: evan_au on 25/12/2017 09:12:18
In Australia, we are mostly metric, although newborn mass is mostly described in pounds (at least amongst the older generation).

TV screens are labelled in inches and centimetres, but most people refer to the inches.

Some overseas food franchises still sell a "quarter pounder burger" or a "foot-long sub".
The staff looks really confused if you ask for a "30 centimetre sub".
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: teragram on 27/12/2017 00:09:51
Whatever happened to the metric system conversion in the United States?
                                 
                                  Reply #7 on: 16/11/2009 16:45:16
                                 
                              
                           
                              I would love to see the US convert to the metric system but there are so many difficulties that it is only a slim possibility at this point. In particular, I have heard that the auto industry would have a terrible time retooling to work in a metric system. I also think there is no political will in the US to convert to metric because, for ignorant political extremists, conversion to the metric system would be deferring to the Europeans.

I started working in UK engineering in 1973. Metrication was already well under way, and has since replaced imperial completely, and enthusiastically. Unfortunately the UK general public wanted none of it. The rule that made UK shops sell everything in grams and kilograms was met with almost revolution by the electorate, although you can still ask for and get, for instance 5lbs (pounds weight, not to be confused with pounds money) of potatoes, or a 1/4lb of boiled ham etc. The medical profession have to weigh patients in KG's, but the staff always convert lbs and ounces for the benefit of the patients. We have the depressing situation where for years our children have been taught in metric at school, and upon leaving are brainwashed by adults into adopting the Imperial system. Whilst I agree with your succinct remark on ignorant political extremists....deferring to the Europeans, even the non-extremist members of the UK general public refuse to accept metrication. The introduction of metric currency in the UK happened overnight (how else could it?). We all got used to it fairly quickly, although not without extensive grumbling. When the subject of using metric units comes up in groups I like to say "who would want to return to the monetary system of pounds, shilling and pence?". This usually results in an embarrassed silence, and shuffling of feet.

Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: alancalverd on 27/12/2017 10:47:43
No metric nation ever put a man on the moon.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Bored chemist on 27/12/2017 11:15:22
No metric nation ever put a man on the moon.
Nor did an metric nation do this
https://en.wikipedia.org/wiki/Metrication_in_the_United_States#Mars_orbiter_blunder

And a metric computer did put a man on the moon- it just translated the displays for the outdated people on board.
"With respect to units, the LGC was eclectic. Inside the computer we used metric units, at least in the case of powered-flight navigation and guidance. At the operational level NASA, and especially the astronauts, preferred English units. This meant that before being displayed, altitude and altitude-rate (for example) were calculated from the metric state vector maintained by navigation, and then were converted to feet and ft/sec. It would have felt weird to speak of spacecraft altitude in meters, and both thrust and mass were commonly expressed in pounds. Because part of the point of this paper is to show how things were called in this era of spaceflight, I shall usually express quantities in the units that it would have felt natural to use at the time."
https://www.doneyles.com/LM/Tales.html
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: alancalverd on 27/12/2017 14:15:48
Ah yes, metric navigation and astronomy. 10 degrees to a circle. 10 hours in a day. 1000 days in a year. Nature just doesn't work that way.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: teragram on 10/01/2018 23:03:36
Anybody remember the slug?
Title: Consultation response
Post by: teragram on 12/02/2018 21:44:27
Anybody remember the slug?

I'll take that as a "no" then.

For the benefit of people living in countries where logical systems of weights and measures are used, the following illustrates the burden that we Brits place ourselves under. It was worse for those in engineering and other technical areas, where the "British Foot Pound Second system" was used.
Quoted from a technical book, first published in 1955:-

Sub Chapter: "System of Units"

"The unit of mass is known as the SLUG,
The unit of force as the POUND WEIGHT,
The unit of acceleration as 1ft. Per sec/sec....."

Question "If a body having a MASS of 1lb.............."(!!!)

I thought it said earlier that the unit of mass was the SLUG?
It goes on to say that "A force of 1lb will accelerate a mass of 1lb at g ft per sec per sec".
So on the face of it the lb(pound) is both a unit of mass and a unit of force.
Regarding the Imperial System, an example following is phrased thus:-

Question:- "A motor vehicle weighing 14cwt. 1qr. 14lb is travelling at a speed of......."
If I remember rightly, had the vehicle been 1lb heavier, the weight might have been given as 14cwt. 1qtr. 1stone, 1lb.
I refer to such units as being in the "Quaint" system.
But, as the world knows following recent political events, us Brits like to make things difficult for ourselves.

If anyone is interested, the SLUG is that mass that accelerates at 1foot per sec per sec when acted upon by a force of 1lb, or 1lb * g.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Colin2B on 12/02/2018 23:05:07
I remember it, but thankfully i have forgotten its meaning along with rods, chains, and a lot of others ive fortunately forgotten.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: syhprum on 12/02/2018 23:21:14
Last on my visit to the USA I bought a weather satellite antenna that requires a 3/4 inch plumbing fitting to mount it on the mast no big deal one would think one can buy 3/4 inch fittings in the UK only they don't fit into a USA socket !
I must patiently wait for my next trip to the USA for the Indy500 when my first trip will be to a plumbing supply store. 
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Colin2B on 13/02/2018 13:22:36
The old imperial for pipes was an inner diameter whereas metric is outer. Thats ok for 1/2 as they will fit, but 3/4 needs an adaptor either a capiliary fitting or a different olive on compression.
I thought the US std was inner dia as well, perhaps someone out there knows.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Bored chemist on 13/02/2018 18:21:46
Anybody remember the slug?
Yes, it is the bastard offspring of the poundal.
Ah yes, metric navigation and astronomy. 10 degrees to a circle. 10 hours in a day. 1000 days in a year. Nature just doesn't work that way.
Nobody said it did.
No metric nation ever put a man on the moon.
A metric  nation got man into space  first.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Bored chemist on 13/02/2018 18:22:29
I must patiently wait for my next trip to the USA
Ever heard of international postage?
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Colin2B on 13/02/2018 22:52:45
Anybody remember the slug?
Yes, it is the bastard offspring of the poundal.
Oh no, not the poundal. I had forgotten, why did you have to remind me?
We had to do it at school, fortunately metric systems were available to ease the pain.
I now need to go to a quiet place and try to forget.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: wolfekeeper on 14/02/2018 04:32:17
No metric nation ever put a man on the moon.
Ironically, the lunar lander computers used metric internally, they only converted back to feet etc. for display purposes.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: alancalverd on 14/02/2018 08:07:16
I remember it, but thankfully i have forgotten its meaning along with rods, chains, and a lot of others ive fortunately forgotten.
Come on, Colin. A chain is the length of a cricket pitch, everywhere. Nothing else really  matters.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Colin2B on 14/02/2018 09:11:02
Come on, Colin. A chain is the length of a cricket pitch, everywhere. Nothing else really  matters.
LOL Id forgotten that as well. Glad to hear someone is keeping history alive. Although i suppose its not history yet.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: evan_au on 14/02/2018 10:17:04
Quote from: alancalverd
Ah yes, metric navigation and astronomy. 10 degrees to a circle. 10 hours in a day. 1000 days in a year. Nature just doesn't work that way.
The French introduced metric time and a metric calendar after the French Revolution.

However, they abandoned it a few years later. One of the complaints was from the workers: they thought that the 10-day week had devalued their weekend.

See: https://en.wikipedia.org/wiki/French_Republican_Calendar
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: alancalverd on 14/02/2018 10:34:09
When history is dead and buried, civilisation (i.e. cricket) will continue, with 6 balls per over (9" circumference, 5 ounces weight). The length of the bat may be no more than 38 inches and the width no more than 4 inches. The overall width of each wicket is 9 inches. Each stump is 28 inches tall with maximum and minimum diameters of 1​1⁄2 inches and 1​3⁄8 inches.

The Roman army recognised that a man's shoe is about a  foot long (they invented standardised shoe sizes), and he needs a pound of bread every day as a minimum marching ration. Having ten fingers makes it easy to count a millia passuum (that's a statute mile) on land.

The Babylonians divided the circle into 360 parts, which is why a minute of latitude is a nautical mile: a very sensible measure (6000 ft) as 1 knot  (nautical mile per hour) equals 100 feet per minute of time. Now 6000 ft is a very comfortable altitude to fly without pressurisation and a rate of climb of 10 knots is easily achievable for most powered aircraft, so air traffic control sticks to these useful units: flying a metric aircraft is full of dangerous ambiguity. 

A fathom is a man's span, so plumbing a channel in bad weather is easy and reliable if your Admiralty charts are British or American, and fraught with difficulty if metric.

Metrication is the bastard son of the French Revolution and not to be trusted.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Colin2B on 14/02/2018 12:18:41
Interesting points Alan, history tends not to forget but leaves puzzles for archeologists.
Measurements of old musical instruments made in Spain and Italy show the proportions don't fit easily into metric, but it appears they used a scale very close to the inch.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Marika on 25/05/2018 10:44:34
At this point it would be too difficult and too expensive. As an engineer from the U.S., I can tell you that we learn both unit systems growing up in school, and learn engineering problems in both systems as well throughout University. We actually hated getting problems in English, metric is a lot easier to solve with. In the industry, unless it's an international contract, a lot of engineering projects are done in English. Many of our measurement tools are capable of English and metric, but we try to avoid or prevent the need to perform conversions on one project. Conversion failure is not fun. That being said, although I have solved many problems in metric, it is still hard for me to visualise how fast 60 km per hour is, but 60 mph is easy.
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: chris on 25/05/2018 10:58:11
done in English

Is that American for "Imperial"?
Title: Re: Whatever happened to the metric system conversion in the United States?
Post by: Marika on 25/05/2018 11:05:01
done in English

Is that American for "Imperial"?

Yes! In the U.S. "English" = "Imperial" and usually we just call metric "SI".