Talk:Metric system

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Contents of the article lede

My changes to the lede were revoked by User:Chetvorno with the comment that they did not meet the WP:NOTE criteria. I disagree.

There is (or there should be) a considerable degree of overlap between the article SI and the article on the metric system. The article on the metric system should, in my view, be written so as to describe the features that are common to SI, to the CGS system and to all the other metric systems, to a lesser extent to show why the different systems evolved and how this is currently being handled. The use or otherwise of metric units on British roads signs possibly has a place in the article Metrication and certainly has a place in Metrication in the United Kingdom, but I do not think that is has a place in the article “metric systems”, and certainly not in the article lede.

The revocation that was done by User:Chetvorno was to reinstate such material into the lede. Martinvl (talk) 16:40, 4 March 2011 (UTC)

I agree with the removal of the irrelevant material about whether metric units are used on road signs and soft drink bottles (which was left over from a previous edit war). But you've also removed (or downplayed) the reasons why the metric system is important in the modern world: that it is the official system of measurement of all but 3 nations, that it is universally used in scientific work and also dominates commercial and personal use. This is more important than details about the retirement of prototype standards. --Chetvorno^TALK 18:10, 4 March 2011 (UTC)

I have reinstated the bit about the three countries. The paragraph that I moved from the lede into a section lower down was inadvertenly deleted by me in a later edit for which I apologise. I trust that I have the balance correct. I agree that the lede could do with a bit more work, but more imprtantly the entire article needs an overhaul, if only to allow it to pass the Class B test. One item that I will be looking at more closely is the section on the history of the metric system and seeing if I can write a serparate article and just summarise it in this article. (Half the material for such an article already exists in Wikipedia, just a matter of copying those sections and massaging them into a single article). Martinvl (talk) 21:18, 4 March 2011 (UTC)

The new article is under development here. Martinvl (talk) 09:37, 18 March 2011 (UTC)

Removal of non-essential material

I intend deleting the subsection "practicality" as it is subjective and unsiourced. I also intend deleting the section "Coincidental similarities". This section is close to trivia. I am planning a total overhaul of the sections "Overview" and "history", so at this stage I do not plan to make any suggestions regardign these sections. Any comments? Martinvl (talk) 09:37, 18 March 2011 (UTC)

Millimetre-newton-second systems

Is the mmNs "system" really a system, or is it just a computer interface? If it is really a system, what are the units of force, energy & power? If these do not exist, then it is really just a user interface with computations being done with whatever normalisation the programmer sees fit. Having been a computer programmer in real life in engineering applications, I suspect the latter. Unless anybody can offer explanation to the contrary, I plan to delete this sub-section (it is unreferenced).Martinvl (talk) 13:05, 21 March 2011 (UTC)

Future shape of article

My view of the future is:

• The section "Overview" will disappear - its contents being moved into other parts of the article.
• The section "Features of the metric system" is moved to the top of the article.

Any comments? I don't think that this will affect its current class. Martinvl (talk) 14:46, 23 March 2011 (UTC)

Is Overview Section redundant?

I woudl like to remove the section "Overview" as I believe that anything of consequence in that section is now redundant (either in the lede or in the rest of the article). I am currently working a new article User:Martinvl/History of the Metric System. It is still in draft form in my work space, but other editors can see what material I am covering. It is possible that certain snippets from the Oversiew section of this article which would otherwise be lost, will have found their way into my new article. Any comments? Martinvl (talk) 14:15, 2 April 2011 (UTC)

I have restructed things such that the Overview section is redundant. The overview itself is (or should be) in the lede. I have also answered the question of lack of references which prevented this article from becing classed as a "B-class" article. Other than tidying up, I plan to add another section which will catalogue the most important cgs and SI units. Martinvl (talk) 19:59, 7 April 2011 (UTC)

Is this article too high-brow?

I have now more or less finished overhauling this article. I believe that I have met most, if not all of the criteria for this to be rated as a "B-class" article, but I still need to go through it with a fine-tooth comb - all help and second opinions appreciated. On reading it, I believe that although it is encyclopeadic, it may be too high-brow for a large class of readers. To this end, I propose writing a parallel article "Metric System overview" which will be targeted at the non-specialist reader. My target audience will be the non-technical reader who has had minimal exposure to the metric system but who is otherwise an average Wikipedia user. To this end, I will mention in passing that electrical units are also part of SI, but I will not labour the point. However, the treatment of prefixes will be given much more prominence than in this article.

Does anybody had a better suggestion for a name - I thought about "Metric System for the layman", but felt that it might be too patronisong. Any suggestions? It is still a few weeks before I start the article as I still need to finish off "History of the Metric System" (Draft in progress at User:Martinvl/History of the Metric System). Martinvl (talk) 17:45, 16 April 2011 (UTC)

I would like to suggest a different course of action: go through the wording of this article and see if it can be expressed in simpler English. I think another article on broadly the same topic would be redundant.Michael Glass (talk) 22:37, 16 April 2011 (UTC)

I recently assisted at a dayschool for would-be editors sponsored by the Institute of Physics. One of the topics that came up was the need for articles "Introduction to XXX", an example being the complementary pair Special Relativity and Introduction to special relativity. In light of this, I have written an article Introduction to the metric system. My target reader is a typical Wikipedia user who, for whatever reason, has studied very little science. Martinvl (talk) 19:47, 10 October 2011 (UTC)

Base 10 or Base 100

By base 10 arithmetic (or decimal arithmetic), I mean arithmetic where there are 10 digits - 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. This contrasts with base 16 (hexadecimal) arithmetic which is often used in computing and which uses 16 digits - 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F or with binary (base 2) arithmetic which used 2 digits - 0 and 1 or actoal (base 8) arithmetic which uses 8 digits - 0, 1, 2, 3, 4, 5, 6, and 7. Martinvl (talk) 12:53, 9 July 2011 (UTC)

Non-English info do not belong in "English-speaking countries" section

In the Metric system#Usage in English-speaking countries section, in the "Variations in spelling" subsection, it lists the translation of kilometre in Italian, German, Malay, French, Greek, Portuguese, and Bulgarian. What do these have to do with "English-speaking countries"? --71.141.123.108 (talk) 00:38, 7 August 2011 (UTC)

This was added to show that the word "kilometre" can be specific to the country concerned, but that "km" is international and is a "symbol", not an "abbreviation". Martinvl (talk) 06:48, 7 August 2011 (UTC)

Coherence

This section of the article currently reads as follows (delinked & dereffed).

The metric system is a coherent system - the various derived units are directly related to the base units without the need of intermediate conversion factors. For example, the units of force, energy and power are chosen so that the equations

force = mass × acceleration

energy = force × distance

energy = power × time

hold without the introduction of constant factors. Many relationships in physics, including Einstein's mass-energy equation, E = mc², do not require extraneous constants when expressed in coherent units. In SI, which is a coherent system, the unit of power is the "watt" which is defined as "one joule per second". In the foot-pound-second system of measurement, which is non-coherent, the unit of power is the "horsepower" which is defined as "550 foot-pounds per second", the pound in this context being the pound-force. Other defined units are derived in a similar way building up on the base units.

This is not correct.

• Foot-pound-second systems are coherent.
  • Gravitational fps systems they are based on the foot, the pound-force and the second. They use the foot-pound force per second not the horsepower as the unit of power.
  • Other fps systems are based on the foot, the pound-mass and the second. The unit of power in these is the pound square foot per cubic second (lb·ft²·s⁻³).
• The imperial and US systems are not coherent.
  • The BTU (1 BTU ≠ 1 lb·yd²·s⁻²), horsepower (1 hp ≠ 1 lb·yd²·s⁻³), the psi and the inHg (1 psi ≠ 1 lb·yd^–1·s⁻¹ ≠ 1 inHg), the gallons (1 imp gal ≠ 1 yd³ ≠ 1 US gal) don't match with the pound and yard.
• Some versions of the metric system are also incoherent.
  • The calorie, the metric horsepower, the are (0.01 ha), the litre, the mmHg don't fit in (not into any system in use).

When talking coherence we must refer to specific versions of the metric system. Coherence is a property of the specific version related to the base units chosen. The SI and the cgs system, for example, use different base units. Each are coherent unto themselves. Talk of cohenence between the two is meaningless. JIMp _talk·cont 10:18, 10 August 2011 (UTC)

Revocation - 25 August 2011

I have undone the changes made by an annonymous editor who left the comment "Correction of a POV statement, as there is no consensus over the paternity of the metric system among the official international organisms(One source given is from the website of an Australian biologist and the other is a TV show from the BBC"

The paper written by the "Australian biologist" (the late Pat Naughton) is in fact a reproduction of a published work by one of the founder members of the Royal Society. Naughton's contributions were to publicise this paper. The BBC video was a report on Naughton's findings. If the annonymous editor can find a reputable source to sho that somebody else made contributions to the metric system before 1668, please amend this article. If you can't find any such references, don't go around accusing people of POV. Martinvl (talk) 19:32, 25 August 2011 (UTC)

Should the 'bar' be in the last table?

Martinvl, by reinstating the bar, you've changed the intent of the table, and thus had to change the text. Sure the SI Brochure catalogs lots of non-SI units, but so what? The table (and text) was clearly based on Table 6 in the SI brochure, "Non-SI units accepted for use with the SI". I was just correcting it. Once you include the bar, where do you stop? There are dozens of other non-SI units. The whole point of the SI is to reduce the proliferation of units used in diferent industries, countries and disciplines. 138.194.23.3 (talk) —Preceding undated comment added 23:37, 30 August 2011 (UTC).

I wrote the part of the article concerned. My apologies if the intent was unclear. My intention was to catalogue those units of measure in Tables 6, 7, 8 and 9 that people see in daily life - for example, my car's handbook quotes tyre pressure in bars (I live in the UK), road signs show maximum allowable weights (masses) in tonnes.Martinvl (talk) 06:47, 31 August 2011 (UTC)

Fair enough, since the article is about the metric system, not the SI. I'd personally profer to wean people off SI-deprecated metric units, by discontinuing references to them. Adamtester (talk) 05:27, 2 September 2011 (UTC)

Text on first picture

The text strikes me as a bit pompous and lengthy. For a start, I don't think a 1 kg mass is a 'measuring device' - it's a reference artefact. The distinction between domestic and 'tradesman' use is unnecessary here. Can someone rustle up a new picture on their kitchen table, replacing the mass with analog or digital kitchen scales? Adamtester (talk) 07:40, 6 September 2011 (UTC)

...or maybe change the wording. The previous picture was a slightly blurred black-and-white shot of the US prototype kilogram with a rather messy backdrop. Thwe words "domestic" and "tradesmen" were chosen to emphasise that metric units were not soley the domain of sceintific laboratories. Martinvl (talk) 07:59, 6 September 2011 (UTC)

Daily express stories

I removed the updates that reference the Daily Express.

Firstly, this article has been crafted so that everything in the lede is repeated in the article. If the articles from The Daily Express and the Manchester Evening News were of any consequence, they should have been in the body of the article, not the lede.

Secondly, the articles concerend were very vague about "EU rules". The newspapers were in fact reporting on posturing by politicians before the publication of consultation prior to the review of EU directive 80/181/EEC, but the reporting was wildly inaccurate. It should be noted that Wikipedia advises newspaper stories should be treated with caution when cited as sources.

Martinvl (talk) 06:26, 13 September 2011 (UTC)

Unreliable sources (13 Sep 2011)

I removed material that was sourced from the British Weigths and Measures Association website.

The Wikipedia guidelines on reliable sources states:

Questionable sources are those with a poor reputation for checking the facts, or which lack meaningful editorial oversight. Such sources include websites and publications expressing views that are widely acknowledged as extremist, or promotional, or which rely heavily on rumor and personal opinion.

The BWMA has as one of its aims the retention of the imperial system of measure and this source must therefore be classed as being a "promotional" and hence, from the point of view of Wikipedia, unreliable. Martinvl (talk) 19:55, 13 September 2011 (UTC)

Should we also remove content sourced from the website of The U.S. Metric Association (USMA), Inc, an organisation that apparently "advocates U.S. conversion to the International System of Units, known by the abbreviation SI (ess-eye) and also called the modern metric system."[1] on the same grounds? -- de Facto (talk). 20:22, 13 September 2011 (UTC)

They should be looked at with caution. You will notice that the reference to their website is backed up by another reference which states the same thing. Martinvl (talk) 07:24, 14 September 2011 (UTC)

Should they be used at all, and if so; why? -- de Facto (talk). 07:51, 14 September 2011 (UTC)

The comments by Which? were taken out of context. This section has been extended to put it into context and has been moved to a more appropriate article Metrication in the United Kingdom. Surveys are always dubious - in the case of this survey, the store onloy asked its customers for their view. The selection of respondents was biased towars the socio-economic group that patronise Asda and are therefore not representative of the UK as a whole. Moreover, the article did not state the exact question asked - at this stage I cannot discount the possibility that Asda were trying to justify a "downsizing" exercise by producing a third-rate survey, not can I discount the possibility that only a certain section of their customers were questioned (the surveys might have been taken when they knew that most of their shoppers where pensioners). In short, surveys of this nature are dubious. Martinvl (talk) 07:19, 14 September 2011 (UTC)

The context was correct - the UK may be officially metric for some measures, but the vast majority of the population still prefer, and use, imperial measures - even for measures which have been metricated. The section now gives an unbalanced view of the UK situation. -- de Facto (talk). 07:58, 14 September 2011 (UTC)

This article gives a world-wide view of the metric system - the English-speaker's view is merely a small section of the article as a whole and metrication in the United Kingdom is a small section of that. It has not gone into depth as there is an article entitled Metrication and a number of other articles that deal with metrication in specific countries. I must therefore ask you to justify why you claim it to be unbalanced. Martinvl (talk) 09:18, 14 September 2011 (UTC)

The section in question, on usage, omits the significant balancing fact that although the UK administration may have been officially partially metricated, that the vast majority of the population still use imperial measures in everyday life, and would prefer it if goods were all labelled and sold in imperial. -- de Facto (talk). 15:23, 14 September 2011 (UTC)

It is well established that reliable sources do not have to be unbiased, see WP:V#Neutrality. However, one must be careful when using biased sources. The things to consider are somewhere between WP:V and WP:NPOV.

Regarding the Which? source, that's actually pretty balanced. It seems to take the Asda survey with a grain of salt ("if Asda’s research is anything to go by") and stresses that there are also younger people who think in terms of kilogrammes. And it only talks about pounds. Also, the situation for miles (more support) and degrees Fahrenheit or many of the more obscure imperial units that have fallen out of use (less support) is clearly different. Therefore this summary, while accurate, was slightly misleading. Hans Adler 09:47, 14 September 2011 (UTC)

The crore and the lakh

The article says "India is mostly metric (though the use of the crore (100,000) and the lakh (10 million) is widespread)". Why are we talking about the crore and the lakh? These are just numbers, they're not non-metric, they're not units. Why are we even giving India special attention at all? JIMp _talk·cont 02:17, 15 September 2011 (UTC)

I guess it's because most metric prefixes are for multiples of 1000, so the metric system is informally tied to thousand, million, billion etc., making it fit less well into Indian practices. This creates an unusual tension between ordinary language and the metric system, and perhaps that should be made clearer. (The article confused lakh and crore. I fixed this.) Hans Adler 06:57, 15 September 2011 (UTC)

Yes ... but it is still a different thing. East Asian (Chinese, Japanese, Korean, ...) numbering systems are based on 10,000, if we're mentioning Indian numbers, we'd have to mention these also ... but these are numbers. JIMp _talk·cont 05:18, 16 September 2011 (UTC)

I have classed India as an English-speaking country. I agree that only 0.25 million Indians who use English as their mother-tounge, but English is the ligua franca of the country - the country's largest newspaper being The Times of India which prints 8 million copies a day. All other languages such as Hindi, Punjabi etc are regional. The same argument can of course be adopted to most of Southern Africa, Nigeria and Ghana. Martinvl (talk) 06:04, 16 September 2011 (UTC)

English may be an official language of India but I would disagree with classing the country as English-speaking. However, my main point is that the use of the crore or lakh is in no way in conflict with the use of the metric system.

• "The Sun is 15 lakh kilometres away." ... metric
• "The Sun is 93 megamiles away." ... not metric

Whether you have six bottles of beer or you have half a dozen you're still counting your beer by the bottle. JIMp _talk·cont 06:41, 20 September 2011 (UTC)

Aren't we perhaps making a mountain out of a mole hill? The article had a single reference to India (and to the Commonwealth countries of Africa). All of these countries (apart from Mocambique) were British colonies, have English as an official language and used the imperial system of measure until some time after the second world war. Martinvl (talk) 07:08, 20 September 2011 (UTC)

Perhaps we are but how should we bulldoze our mole hill?

• The section is entitled "Usage in English-speaking countries".
  • If the government decides to declare English as an official language but the people don't decide to speak English, is the place an English speaking country? The US has no official language, is it not an English speaking country?
  • In the "Degree of usage" subsection we speak of "all nations in the world except for Myanmar (Burma), Liberia and the United States". Then we go on to talk specifically about Liberia (which like India is officially "English speaking" but the reality may be different) and about Burma which is not English speaking by any measure. We then go back to a general discussion of metric in the world in general with a Hong Kong example.
  • In the "Variations in spelling" subsection we talk about the word for the kilometre in Italian, German, Malay, French, Greek, Portuguese and Bulgarian. Then go on to note that "Similar variations are found with the spelling of other units of measure in various countries ..." before returning to English language usage.

The solution is simple: the section is not really about usage in English-speaking countries but about usage around the world so change the title.

• There is no conflict between the Indian numbering system and the metric system. You're still using the metric system whether you have ten litres, three dozen litres, four score and eight litres, two and a half myriad litres or five crore litres. These are numbers not units. Delete the talk about the lakh & crore.

I'm going ahead and editing. JIMp _talk·cont 07:57, 20 September 2011 (UTC)

Extent of metrication

I have undone [[User:DeFacto]'s changes.

The metric system is used in the United Kingdom for “for economic, public health, public safety or administrative purposes” except

• Where international conventions or agreements in the field of air and sea transport and rail traffic requires otherwise.
• Pints may be used for dispensing draught beer and Cider or for the sale of milk in returnable

Containers.

• Miles, yards, feet and inches may be used for “Road traffic signs, distance and speed measurement”.

The above wording has been paraphrased from relevant EU directive. I believe that my wording encompasses the above. User:DeFacto's wording stretches the point. Martinvl (talk) 19:28, 30 September 2011 (UTC)

The article contains the sentence: "In the Commonwealth of Nations the imperial system has officially been replaced by the metric sytem." I have flagged it as dubious because it is factually incorrect. We know that the UK, at least, far from having replaced the imperial system with the metric system, it still mandates imperial units for some measures. Pages from Adler [sic] are cited in support - can someone (preferably the original contributor) please supply the quote from the book that supports that assertion so that we can verify the accuracy of the statement, and decide how to rectify the clear anomoly. -- de Facto (talk). 20:12, 30 September 2011 (UTC)

The Wikilinks for "Australia", "Canada" etc link to articles Metrication in Australia, Metrication in Canada etc. Regarding the UK I do not intend typing out four pages. Within the UK, the law permits the use of imperial units for anything that falls outside the scope of the EU Internal Market, for road signs and distances (miles, yards, feet and inches), for the sale of draught beer and cider and for the sale of milk in returnable containers. Imperial (or US) units may also be used anywhere as supplementary units. Note that in many cases, retailers remain within the law by writing "568 ml - 1 pint". Martinvl (talk) 07:30, 3 October 2011 (UTC)

I've re-worded the factually inaccurate statement - in the absence of a supporting RS. The imperial system hasn't been totally replaced in all countries of the Commonwealth. -- de Facto (talk). 08:42, 3 October 2011 (UTC)

On the extent of metrication, there are some issues that the following sentence in the article raises: "The United States is the only industrialised country that has not adopted the International System of Units as its official system of measurement, although it has been sanctioned for use there since 1866."

What exactly constitutes an industrialized country? Is there some sort of list of industrialized countries somewhere? Who says that all industrialized countries have an official system of measurement? Where does it say that? Some citations would be very helpful I believe.YouMakeMeFeel: (talk) 02:44, 26 October 2011 (UTC)

The simple answer is to look at all the countries that have not metricated. According to the CIA handbook, they are the United States, Liberia and Burma. This is a case where WP:COMMONSENSE rules. Martinvl (talk) 19:43, 26 October 2011 (UTC)

You still failed to answer the question of what constitutes an industrialized country among other questions. So Somalia uses the metric system? Who says so? It is definitely not common sense that every country in the world, let alone every industrialized country of the world uses the metric system, and it is bogus for you to claim such a thing. I raised completely valid points that need to be addressed. YouMakeMeFeel: (talk) 23:17, 2 November 2011 (UTC)

NIST, as US Goernment Agency said so - you had better ask them what their criteria was: for me to hazard a guess would be WP:OR. Martinvl (talk) 08:43, 8 November 2011 (UTC)

If a country has switched from being an primarily agrarian one to an economy that focuses on the production of non-agrarian goods, then it has industrialized. It is not that difficult to understand. Without having an official system of measurement (metric, imperial, cubits and hands, doesn't really matter what the system is based on) it is difficult to industrialize (not impossible, but it is really difficult to successfully industrialize without it), as a result, each country has historically gone to an official system of measurement before they became industrialized, thus the reason for the assertion that all industrialized countries have and official system of measurement. However, that does not translate to say that that-system is the metric system (most of the present industrialized countries were not on metric when they became industrialized — the US and UK as two examples; UK began industrializing in the 18th century, but didn't begin officially switching to the metric system until 1965). — al-Shimoni (talk) 03:27, 20 November 2011 (UTC)

To give some further background on why the cited NIST document said what it said: Before industrialisation there was the occasional merchant's handbook that contained the conversion factors for the various local weights and measures. With industrialisation, the proliferation of standards became a problem due to increased mobility. E.g. many of the first railroads in Germany were built by English engineers. That's when a consensus developed that more uniformity was required, but no consensus how to achieve that or which country should lead the efforts. Metrology became a fashionable field of research, and the writers of the era wildly exaggerated how complicated the old systems actually were, e.g. with incorrect claims that a unit called the "King's foot" was adjusted to each new king. A process of consolidation started in which many of the old local units were superseded by more common units used for other purposes in the same region, or for the same purpose in neighbouring regions. Existing systems were reformed and simplified (England) or completely replaced by new, 'scientific' systems (France and Prussia). The French system was the simplest and most radical. Even in the radical context of the French Revolution, the first attempt to make it mandatory for the entire population, supported by the systematic destruction of all old measuring instruments and distribution of new ones and conversion tables, ultimately failed. France and territories under French occupation reverted to a system in which certain easily remembered multiple had the traditional names, e.g. the pound of 500 g. (Some of these conventions were so successful that they I are still used today. Older Germans still buy "half a pound of butter", i.e. 250 g.) All these efforts were made for economic reasons which, for industrialised countries but not for pre-industrial countries, outweighed the cost of switching. Hans Adler 09:17, 20 November 2011 (UTC)

Less convenient non-integer quantities for common divisions

The following was added by DeFacto.

The use of decimal multiples also results in less convenient non-integer quantities for common divisions. A foot can be divided in four different ways (by 2, 3, 4 and 6) with an integer number of inches resulting and a yard in seven different ways (by 2, 3, 4, 6, 9, 12 and 18).

There are 2²·3 inches in a foot and 2²·3² inches in a yard so actually there are five ways of dividing the foot and eight ways of dividing the yard with an integer number of inches (not counted above was division into single inches, i.e. into twelve and thirty-six respectively). However, there are 2²·5² centimetres in a metre so there are likewise eight ways of dividing the metre into an integer number of centimetres: 2, 4, 5, 10, 20, 25, 50 and 100. Furthermore there are 2³·5³ millimetres in a metre thus fifteen ways of dividing the metre into an integer number of millimetres.

Thus doesn't it somehow miss the point to be counting the number of ways this unit can be divided into an integer number of that? I think that the real issue here is that it can be more useful to be able to dive something into thirds (sixths, twelfths, etc.) than fifths (tenths, twentieths, etc.). Now we come to the question as to how many threes are there in the other system ... what other system?

The inches, feet and yards example given is just that: an example from another system. The metric system has replaced (and is continuing to replace) a variety of customary systems (not just one) which use a variety of different ratios between units (fourteen pounds to the stone, five and a half yards to the rod). The use of decimal multiples can result in less convenient non-integer quantities for common divisions, sometimes it goes the other way and sometimes the customary system was (partly) decimal to begin with.

JIMp _talk·cont 14:02, 21 November 2011 (UTC)

I deliberately excluded division by 1 (and by itself) - for the obvious reasons. As you say the "common divisions" (useful divisions) are by 2, 3, 4 and 6. Feel free to re-word the paragraph if you think it could be put more clearly. -- de Facto (talk). 14:14, 21 November 2011 (UTC)

One, obviously, but I'd've included 12 or 36; though it may be moot if you agree that it's not really about the count. Let's work on some kind of rephrasing. JIMp _talk·cont 14:22, 21 November 2011 (UTC)

And see below - this could be considered as part of an initiative to add some balance. -- de Facto (talk). 14:41, 21 November 2011 (UTC)

More 'cons' required to counter the 'pros'

Following on from the discussion above I feel we, to give a more neutral POV and interest to the article, need to add more of the 'cons' of the metric system - the article feels unbalanced in favour of the metric system to me at the moment. We shouldn't be writing a purely promotional article. We need some more examples of disadvantages. One avenue, possibly, is that typically, proponents of English unit based systems mention the advantages of the human-friendly, intuitive and readily comparable size of their units: 1 inch is about a thumb width, 1 foot (unit) is about a foot (human) length, 1 yard is about the length from outstretched-thumb-to-chin or a man's stride, etc. Are there any other ideas for what might be considered to be disadvantages of the metric system over English-unit systems that we can work in? -- de Facto (talk). 14:39, 21 November 2011 (UTC)

This is a fair call, however, let's take care not to equate the disadvantages of the metric system with the advantages of the English systems. I'm suggesting a more general view: it's not the metric system vs the imperial and/or US system but the metric system vs the various alternatives. The customary systems it has replaced (and there are many of these), are, of course, of particular interest but what of other systems: systems proposed but not adopted, natural systems of units, hypothetical possibilities etc.? Let's focus on the pros and cons of the metric system. JIMp _talk·cont 15:29, 21 November 2011 (UTC)

Lets not get too carried away by this. First of all, how many fluid ounces in a pint? 16 or 20? Depend whether you are talking about US or UK fluid ounces. Which are the larger, US fluid ounces and pints, or UK fluid ounces and pints? A contorted question to which there is no simple answer as the US fluid ounce is the larger and the UK pint is the larger. If we are to go into a discussion about the ease of multiples, we also need to go into the question of consistency of units between countries - just visit the article foot (unit) and you will get a feel for the problem. Now ask how we measure very small quantities in imperail units - we don't. Next ask how we equate mechanical power and electrical power in the imperial system - which partcular mechanical power are we talking about - if it is horsepower, which units of force are we using to define the equation

power = force x distance/time.

The metric system handles this in a very simple way - power is measured in watts regardless of whether it is electrical, mechanical, radiation or any other form. British car reguistration certificates have the car's power in kilowatts, not HP. The manufacturer's plate on kettles likewise have power in kilowatts.

As DeFacto was saying about ease of multiples? If he wants a discussion about that, then we need to include all the rest which will make the artcile appear so one-sided as to be very POV.

Martinvl (talk) 16:04, 21 November 2011 (UTC)

It's no even as simple as metric vs imperial or US. There's the imperial pint (~568 ml), the US liquid pint (~473 ml), the US dry pint (~551 ml) but what about French pint, the German pint, the various other pint-sized units formerly in use. To be fair, though, the metric system is not completely immune to inconsistency: power is measured in watts, yes, and in calories per minute and kilowatt-hours per year (no, these are not SI but they're still metric). As for consistency between countries, is this a pro of the metric system? This consistency could also have been achieved by the global adoption of the furlong-firkin-fortnight system. List the pros of the imperial system as pros of the imperial system on the article about the imperial system not here as cons of the metric system. List the cons of the US system as cons of the US system on the article about the US system not here as pros of the metric system. List the advantages, disadvantages, misadvantages and whatever of metrication on the article about the pros and cons of metrication (yes, there is such an article). What's wanted here is a focus on the metric system itself and if we're to look at alternatives, a very general view of them. JIMp _talk·cont 00:30, 22 November 2011 (UTC)

Jimp, I agree that the pro/con contents of this article should be based on the pros and cons of the metric system itself (and not simply the SI vision), and not of some idealised "other" system and certainly not of some falsly construed "other" system. Fair comparisons may be informative though. I see that some other editor has already removed the paragraph that I added, and that we were going to work on here. Perhaps we can review what's left first, and see if it complies with this "fair comment" (NPOV) scenario. -- de Facto (talk). 08:38, 22 November 2011 (UTC)

In fact, although the other editor's edit comment claimed "Decimal multiples: Removed references to imperial units -see talk page", all that was removed was the entire point that I added, including both references to imperial units and to metric units, but left in place the previously present point, including all its references to imperial units! I've corrected that now, restoring my point, less references to imperial units and removing references to imperial units from the previous point. -- de Facto (talk). 09:34, 22 November 2011 (UTC)

Variants comparison table

Variants of the metric system

Quantity CGS MKS MTS length (l) centimetre (cm) metre (m) metre mass(m) gram (g) kilogram (kg) tonne (t) time (t) second (s) second second velocity(v) cm/s m/s m/s acceleration (a) gal (Gal) m/s² m/s² force (F) dyne (dyn) newton (N) sthene (sn) pressure (p) barye (Ba) pascal (Pa) pieze (pz) energy (W) erg (erg) joule (J) kilojoule (kJ) power (P) erg/s watt (W) kilowatt (kW) viscosity (µ) poise (p) Pa·s pz·s

Variants of the metric system

	CGS	MKS	MTS
l	cm	m	m
m	g	kg	t
t	s	s	s
v	cm/s	m/s	m/s
a	Gal	m/s²	m/s²
F	dyn	N	sn
p	Ba	Pa	pz
W	erg	J	kJ
P	erg/s	W	kW
µ	p	Pa·s	pz·s

Variants of the metric system
Quantity CGS MKS MTS length centimetre metre metre mass gram kilogram tonne time second second second velocity cm/s m/s m/s acceleration gal m/s2 m/s2 force dyne newton sthene pressure barye pascal pieze energy erg joule kilojoule power erg/s watt kilowatt viscosity poise pascal-second pieze-second

On 1 December 2011 I added a compact table to the Variants section. Soon afterward user:Martinvl changed it to be more explicit and thereby also wider. I don’t feel strongly about it, but since most of its contents is explain in wordily details nearby, I would prefer a table as compact as possible. Both tables are cited above for easy reference, I’ve remove floating from my version though. — Christoph Päper 15:35, 6 December 2011 (UTC)

I think I can see your point, but for me it's outweighed by the fact that your version of the table is so cryptic that I would hardly be able to use it. At the very least the left column needs to have the full names of the dimensions, not just single letters that may or may not be fully standardised. The l isn't recognisable as an l (small version of L) as opposed to an I (capital version of i), I wasn't aware that W is a symbol of energy (I think there are many around, with E being one of the most popular), I even forgot about the obvious meaning of P, and even if all this were clear, it's still not immediately clear from just reading the first column what it means. Adding the full names of the dimensions is easier than adding an explanation and needs less space. I am more or less indifferent about the full names for the various units, but you should keep in mind that this kind of article has a lot of readers who are used to the traditional American or English system of units and may not be able to read the unit abbreviations easily. Hans Adler 16:52, 6 December 2011 (UTC)

I agree with Hans that these things are best spelt-out especially pressure since the whole P vs p thing doesn't work: we can't use P for pressure since P is for power so we must use p ... but p is for momentum. So perhaps we should have "pressure (P or p)" & likewise "energy (E, W, Q ... etc.)". Now things coul easily get out of hand but what do we need these letters for anyhow? If we have things spelt-out, we can get rid of them altogether and slim the table down a little. JIMp _talk·cont 02:23, 10 January 2012 (UTC)