Talk:International System of Units/Archives/12/2017

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In this subsection, besides SI and ISQ acronyms, we have: CGPM, NIST, CIPM, CCU, JCBM, BIPM, ISO/IEC. Baaaa, Baaaa, black sheep. The section is incomprehensible. How about some plain speakin'. OMG... there's a hairy [Note] in the middle of that section with 15 more organizations and 12 more acronyms. 8-0 Sbalfour (talk) 23:14, 19 December 2017 (UTC)

Fixed up. Sbalfour (talk) 03:14, 20 December 2017 (UTC)

The metric units were originally based on common notions because people needed readily available ways of measuring things. And those notions still apply, because the re-defined quantities are simply refined assessments of the ancient measures. Yet those measures are nowhere to be found. How much is an amp? Would it power a whole room full of electronic stuff like TVs, or just one light bulb, or maybe only a night light? I think most people won't know. Even in a laboratory, I don't measure newton-meters to know if I have an amp. If I can at least measure voltage and have a few resistors lying around, I can get amps. I think it's worth a section, both for the history and intuitive notions. Sbalfour (talk) 20:39, 19 December 2017 (UTC)

Done. Sbalfour (talk) 20:27, 20 December 2017 (UTC)

Done. Chunks of information (level 3/4 subsections) are now immediately adjacent to related information, pointing out duplicate material which has been merged and deleted. Sbalfour (talk) 22:45, 21 December 2017 (UTC)

Section

I've cut it down by a little more than half to the relevant material. It'still too big. Time to move on. Sbalfour (talk) 06:48, 22 December 2017 (UTC)

In the section

The impact of the 11th CGPM, whose final proposals became the modern SI, was way big. Among other things they dumped the physical artefact of the standard metre in favor of definition in terms of certain emissions of the krypton 86 atom. The two biggest headaches of measurement standards were antequarian physical artefacts, we just got rid of one, and we don't note it? We could expand that one sentence, covering the integration of proposals that became the SI, detailing their origin and how they evolved, the associated impetuses for change, and never mention obscure committees, organizations and acronyms, interim reports, pamphlets and documents. That pithy description could displace all of the

It's absolutely fascinating how James Watt defined how much work a horse could do (a horsepower, of course), and William Siemens (for whom the later SI unit siemans was named) devised a unit of power, a watt, based on electrical quantities, then precisely defined a horsepower in terms of it, from how fast a horse turned a dynamo! The resulting measures became the industrial standard for evaluating steam engines. Where is all of that? There's a vwhole lot of vital and captivating tidbits associated with the science. Who'd ever think measuring a horse was science? There's more, though not terribly relevant to this article: a span, a unit of measure, the length of a human hand from wrist to middle finger-tip, was originally used to measure the length of a horse! It didn't much matter that spans differed somewhat, because it didn't much matter how long a horse was. Sbalfour (talk) 23:13, 21 December 2017 (UTC)

The section

As a separate issue, this is too much of a "how-to" manual. There's a whole 200-page book covering this stuff.

I don't know what should go in this section, but it should be very pithy, very understandable and very usable.

Our sister article, metric system devotes only 8 lines to this topic, and it is a GA article, in many ways a better and more balanced one IMHO. I'm prepared to axe the whole section.

Sbalfour (talk) 20:36, 22 December 2017 (UTC)

I've removed bulleted detail and Chinese/Japanese lexicography, leaving a plausable section of general statements. The section states little more than that the SI also has standards for these things (of course it does). The section teeters on the brink of extinction. It must be made useful or go. Sbalfour (talk) 22:32, 22 December 2017 (UTC)

The two introductory paragraphs are history, and do not belong here; they might be moved to the history section. The conventions (case etc.) for English should remain (general conventions for unit names and symbols in the two subsequent subsections). I would also put the history section last. —Quondum 04:04, 23 December 2017 (UTC)

So, bring back the bulleted items, but only for English? That's a lot of detail, and there's a lot more that wasn't transliterated from the official definition. I'll try to present it in a more usable and maybe condensed way. I see, like others who have commented, you wish to deprecate the History section (last in line is least in note). Maybe, we just chop it down to whatever is of note for this article, which is not about history or the history of measurement or science. I haven't done it, because chopping large chunks out of the encyclopedia goes against the grain, and may be controversial - somebody's work is being lost, and I feel for them. Sbalfour (talk) 17:18, 23 December 2017 (UTC)

I was only looking at what is currently there. I'd have to review what was there previously to sensibly answer you. I'm not a fan of too much detail. But the SI does provide some simple lexicographic rules, which are helpful to remember when using SI to represent quantities. This much is worth having. —Quondum 19:28, 23 December 2017 (UTC)

I want to show you something (I've edited the text out of this section a little):

At its 23rd meeting, held in 2007, the CGPM recommended that the CIPM should continue to investigate methods to provide exact fixed values for physical constants of nature that could then be used in the definitions of units of measure in place of the IPK, thus enabling the transition from explicit unit definitions to explicit constant definitions.

Somebody is going to investigate something

At a meeting of the CCU held in Reading, United Kingdom, in September 2010, a resolution and draft changes to the SI Brochure that were to be presented to the next meeting of the CIPM in October 2010 were agreed to in principle. The proposals that the CCU put forward were:

Somebody proposed something (maybe the following are worth reading, omitted here to make my point)

The CIPM meeting of October 2010 reviewed progress towards establishing fixed values for the constants but found that "the conditions set by the General Conference at its 23rd meeting have not yet been fully met. For this reason the CIPM does not propose a revision of the SI at the present time".

somebody reviewed something

At the 24th CGPM meeting, held in October 2011, the CIPM sponsored a resolution in which the requisite definition changes were agreed to in principle and in which the conditions required to be met before the redefinitions could be implemented were restated.

somebody made a resolution to do something

By November 2014 the conditions set out at the 23rd meeting of the CGPM for the unit redefinitions had still not been met, and the 25th meeting of the CGPM, held in November 2014, adopted a similar resolution encouraging further work towards establishing fixed values for the fundamental constants.

somebody made another resolution to keep on doing something

The redefinitions are expected to be adopted at the 26th CGPM in November 2018. The

CODATA task group on fundamental constants

has announced special submission deadlines for data to compute the values that will be announced at this event.

something is expected to happen ^{[speculation?]}

Where's the science: 1) Exactly what is being proposed? 2) What are the reasons for those proposals? Only the answers to those two questions matter here. Start there, and answer them so someone can read the answer - no bullet items (skip dates, acronyms, organizations, documents, and anything else people say or do that don't answer the questions).

Sbalfour (talk) 23:03, 22 December 2017 (UTC)

Your point is good about waffle: we do not need a blow-by-blow recounting of the um-ing and ah-ing of the CGPM and CIPM. This belongs in the main article on the proposed redefinition, not here. On the other hand, do not be discouraged by the extremely conservative phrasing of the discipline. The process has proceeded further than listed here. In brief, the proposed definition has been settled, including final values for the fundamental constants, and it seems inconceivable that the proposal will not be ratified or that it will not take effect on the specified date in 2019. So you can add to your list of things that matter: 3) When it will happen. The "main article" (

Proposed redefinition of SI base units) contains a lot more specific information. Your point 2 probably belongs there and not here. But giving a sense that tightening up of the SI through redefinition is imminent does belong here. —Quondum

04:21, 23 December 2017 (UTC)

Ok, I'll fix up as per your suggestions. Sbalfour (talk) 17:21, 23 December 2017 (UTC)

If I consider this article as a college paper whose subject is the title of the article, what grade should it get? After some consideration, I believe it would not get a grade, but rather be returned for revision with the following suggestions/recommendations:

• focus: 60% of an article on science is history - cut it down to 20% at the utmost of article text exclusive of tables and lists. For this purpose, metrication is a separate topic, and that section can be removed or merged into the article with that name. This is a mostly experimental science, and the section on how the units are realized is the experimental description, so would plausibly be the most technically precise and in-depth part of the article
• coverage: the entire 22 item Derived units section has 1 paragraph of text - by enumeration, this would be the largest part of the article; no coverage of candela and kelvin base units; the MKS and cgs systems are mentioned only in connection with electricity, when they are direct predecessors of the SI and need to be elaborated (1st half of 20th century)
• structure: mostly done, but elimination/condensation of sections will likely suggest some further reorganization; the structure should be organized in serial order starting with those subsections most pertinent to the science followed by those progressively less pertinent;
• exposition & style: say what you want the reader to know in words/text, rather than tables and factoids; in presentation, the most pertinent sections will be the largest in size and greatest in depth and detail, and the least pertinent ones the smallest and most topical. Style should progress from precise technical diction in the science sections to a narrative summary style in the history and cultural sections.
  • level: the article is at the microscopic level in detail; back out three levels; the article is not topical, nor technical but should be an accessible description of the science; avoid technical jargon, but try to be precise. Organizations, documents, proceedings, resolutions, etc should be in footnotes that detail and support the text, rather than the text itself
• context: embed article in historical, political and cultural context; while there is a History section, it does not cover the thrust of history, only the events

Sbalfour (talk) 21:21, 24 December 2017 (UTC)

I like your approach to what is well-organized content. "Pertinent to the science" would need definition, and I might not agree about words always being preferred to tables. Often, when the form of the information is repetitive (as it is with the base and the derived units), a compact table with a text introduction is far easier to interpret, and works better for reference (e.g. the student that wants to get a comprehensive list, or check up on the definition of any specific unit). —Quondum 21:50, 24 December 2017 (UTC)

The SI is capable of measurement of any physical quantity, That would be the 7 base units, because the others are defined in terms of those. I have to think about that. How about the entropy of a black hole? Maybe it's true. It's a tall statement. I hope it isn't a tall tale. Along with those, we need 4 invariant constants of nature. Some things can't be measured for reasons that have nothing to do with units: Heisenberg uncertainty principle, and Godel's incompleteness theorem. Maybe we bring all these things together into a short section on foundations and applicability? Sbalfour (talk) 20:58, 19 December 2017 (UTC)

That is a very strong claim, whose validity depends on the definition of "physical quantity". At the very least it needs a source to back up the claim. Perhaps it means "any physical quantity of the ISQ"? Dondervogel 2 (talk) 21:09, 19 December 2017 (UTC)

I changed this to "The SI is capable of describing any measurable physical quantity," which deals with the issue of quantities that can't be measured per, for example, the Heisenberg principle. Entropy can be measured in J/K (joules per kelvin), so the entropy of a black hole can be expressed in SI units even if it is just a calculated value and even if that value is infinity -- or so I think. The statement, which in context refers to non-SI units still in common use, probably means something a little different than "SI can measure absolutely anything [including the precise location and momentum of an electron]." I think it means "SI is sufficient for reporting any value encountered in the scientific literature [but nevertheless non-SI units persist in common use]." It refers to units like the hour, mmHg and electron volt. Roches (talk) 10:12, 20 December 2017 (UTC)

I like that: We could say "SI can measure anything we used to be able to measure; it can also measure by extension, anything we need to usefully measure." (technical diction required) Sbalfour (talk) 16:59, 21 December 2017 (UTC)

This is still very strong. I think that what is meant is that SI provides units that in combination are sufficient for ascribing scale to known dimensions for physical quantities. There are critiques that challenge the completeness of this claim. The designation and handling of "dimensionless" quantities (angle, phase, information, exponential decay, entropy, count) is problematic, there are physical dimensions that are overlooked (such as color charge), and there are inconsistencies and lapses in how dimensions and units are defined (as with the candela and sievert). So I would say that the claim is downright false, and should be removed or substantially reworded. —Quondum 14:27, 22 December 2017 (UTC)

Well, be BOLD! and fix it, no objection here. Can we say something simple and informative about what SI measures? I'm struggling with it myself; why are there just 7 measures? 7 dimensions of mass and energy? We don't have a unit of volume/capacity or area anymore. So what matters? Sbalfour (talk) 21:05, 22 December 2017 (UTC)

Those 7 dimensions are just an arbitrary choice. In principle (assuming something like a "theory of everything" describing the relation between all things that can be measured) one dimension is sufficient. For example a stupid way to define a system of quantities would be to assign the same dimension "length in metres" to both length and area. In this system of quantities the formula to calculate area would be "area=constant*length*length" and one would need to define a physical constant e.g. "constant=42/metre" which would of course also appear in a lot of other formulas. It sounds crazy, but it is a valid metric system of measurement that can easily be used to describe "anything we need to usefully measure". From a physical point of view, e.g. General Relativity, the SI system with a constant=2.99792458*10^8*metre/second for the speed of light and thus different units for length and time (hence also electric and magnetic fields...) is no less stupid. The only difference is: It provides an internationally agreed standard based on historical measures and practical considerations for everyday life usage.--Debenben (talk) 12:40, 25 December 2017 (UTC)

For the time being, I think that this edit sufficiently resolves the problem. —Quondum 03:38, 26 December 2017 (UTC)

What's meaningful? - because this article's history isn't. Let's see... in the first three paragraphs of the first subsection of history, we have: 7 named scientists; 5 dates to the day; 2 named cities and another named place, the 'Archives'; 3 laws (one ambiguously as 'assembly adopted'); three groups, the committee, the Assembly and the Academy. And knowing all of those things doesn't tell me anything about what happened there. Conversely, to understand what happened there, I don't need any of those things!

I've fixed up some of this, but it needs more; the warp and weft of history are still missing. Sbalfour (talk) 19:37, 25 December 2017 (UTC)

Let's start with the eras we're going to deal with and give them names that focus us on what happens there:

• the renaissance (14th-17th centuries)
• the age of reason and revolution (18th century)
• the golden age of science (19th century)
• science and industry (first half 20th century)
• science and nature (second half 20th century)

These are the landmark events:

• 1668 John Wilkins length, volume and mass
• 1670 Moulton's perimeter of the earth length basis
• 1799 mètre des Archives and kilogramme des Archives: the artefact-based system
• 1860 Gauss' second
• 1875 Metre convention
• 1901 Georgi's ampere
• 1948 the working paper
• 1960 the birth of the SI

  the retirement of the standard meter artefact

• 2019 the retirement of the standard kilogram artefact

• And there is a separate history of the applied science, which we beguilingly call metrification.

These are the evolutionary forms of the SI:

• the French metric system, defined by the law of 1799:loi du 19 frimaire
• the cgs system
• the Metre Convention -> the MKS system
• the precursor (1948 initial formulation)
• the SI itself

Science is embedded in history, and history begets science. The reason great discoveries and inventions occur as they do, is because they must. The hand of providence moulds the forces of history: the moral imperative of the renaissance and enlightenment drives the forces that foment the events of these times: if Lavoisier, Legendre and Laplace had not formulated their system when they did, some other 3 men in that time and place would have; and if it did not happen in that place, it would have happened in some other place at that time or soon after. If we understand history in these terms, its statement will be colorful, opinionated and compelling. The bland and deadening text of the encyclopedia is an injunctive. We can do better, and keep within the bounds of scholarship.

We cannot do without that History. We get no points for scholarship - it's already done, detail by painful detail. We do get points for force and effect. We've got the tail of the horse. Where's the thew and sinew? Write, compose, argue, then the tail. The history is currently 38 paragraphs; do it in 10. Don't use any Name longer then 10 characters. Before you write, read a book on Natural Theology (W. Paley), the Age of Enlightenment, the Industrial Revolution, Science in the 20th century. The big things. This is what people believe(d) in; science is what they do about it. I could teach this course. Sbalfour (talk) 23:05, 23 December 2017 (UTC)

I realize that this talk page section might be better placed on the talk page of the History of the metric system article, and that might be my next project. But while I'm thinking about it, I'm going to elaborate it here. The whole History section may ultimately be ejected from the article, as other editors have suggested or implied. Sbalfour (talk) 17:31, 24 December 2017 (UTC)