Talk:Proposed redefinition of SI base units

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Good article Proposed redefinition of SI base units has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can reassess it.
Article milestones
Date Process Result
April 11, 2013 Peer review Reviewed
July 5, 2013 Good article nominee Listed
Current status: Good article
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Revocation of 31-Jan-2011[edit]

It is a moot point whether one writes 2 x 10-8 or 20 x 10-9. The former keeps the mantissa in the range 1.0 to 10.0 while the latter maps onto μg. In such circumstances, I think it appropriate to keep the article in line with the original text. Martinvl (talk) 20:17, 30 January 2011 (UTC)

Rollback of 29 March 2011[edit]

I have rolled back a series of changes that were made earlier today. While I agreed with some of the changes, I did not agree with them all. In particular,

  • The CCU wrote to the CIPM - see the title given in the reference.
  • Hard spaces between numbers and symbols were removed. The hard spaces were put there to ensure that the value and symbol were not separated by line breaks. This is standard practice.
  • The way in which negative superscripts was handled - for example changing J·K−1 to J/K. While I agree that these two have the same meaning, I used J·K−1 for the sake of consistency with the rest of the article.
  • The symbol "sec" is not the recognised symbol for "seconds" - "s" is.

Martinvl (talk) 21:08, 29 March 2011 (UTC)

Impact on reproducibility[edit]

The current text contains a table, introduced with:

"The following table catalogues the improvements"

They don't look like they are all improvements, as in half the cases the change is from an exact value to an uncertain value. I suggest the table catalogues the changes.
—DIV (138.194.11.244 (talk) 07:41, 16 April 2012 (UTC))

Following your observation, I am revising this section to include all constants listd in the reference. Martinvl (talk) 10:12, 16 April 2012 (UTC)

GA Review[edit]

This review is transcluded from Talk:Proposed redefinition of SI base units/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Adabow (talk · contribs) 06:52, 21 June 2013 (UTC)

  1. Perhaps link the background section to the History of the metric system using {{main}}
  2. Can a citation be added for the paragraph concerning the setting-up of the CGPM, CIPM and BIPM?
  3. "In 1889 the CGPM took delivery" - what does "took delivery" mean?
  4. "the mandate of the CGPM was extended to provide standards for all units of measure, not just mass and length" - before reading this, it is not clear that the three organisations only dealt with mass and length; please make this explicit earlier on.
  5. "In the ensuing years" - vague. Is there a known end date?
  6. Can you explain how the conditions set by the General Conference were not fully met?

Adabow (talk) 07:51, 21 June 2013 (UTC)

Proposer

I have taken on board your proposals and have implemented them. I have also ensured that the date passed to the accessdate parameter is consistent across all citations. Martinvl (talk) 10:49, 21 June 2013 (UTC)

Continuing...

  1. It is not stated in the background section that/when the speed of light was fixed.
  2. Is "an elementary charge" correct, or should it be the elementary charge?
  3. Please provide a citation for the current definitions of the base units.
  4. There are some great analyses about the consequences of the redefinitions (eg effect of amp redefinition on vacuum permeability, vacuum permittivity and impedance of free space), but it is not all referenced
  5. Ditto with the example of potentially defining kg from G - WP:OR
  6. Who is Leonard?
GA review (see here for what the criteria are, and here for what they are not)
  1. It is reasonably well written.
    a (prose): b (MoS for lead, layout, word choice, fiction, and lists):
  2. It is factually accurate and verifiable.
    a (reference section): b (citations to reliable sources): c (OR):
  3. It is broad in its coverage.
    a (major aspects): b (focused):
  4. It follows the neutral point of view policy.
    Fair representation without bias:
  5. It is stable.
    No edit wars, etc.:
  6. It is illustrated by images and other media, where possible and appropriate.
    a (images are tagged and non-free content have fair use rationales): b (appropriate use with suitable captions):
  7. Overall:
    Pass/Fail:

Placing review on hold now. Adabow (talk) 07:07, 22 June 2013 (UTC)


Proposer

I have taken the liberty of replacing bullet points with numbers to simplify cross-referencing of comments.

The outstanding issues in the first set of comments have been handled as follows:

  • Item 4: In this change, the text "under which three bodies were set up to regulate units of measure that were to be used internationally." was replaced by "under which three bodies were set up to take custody of the international prototype kilogram and metre and to regulate comparisons with national prototypes.[1],[2]" Martinvl (talk) 15:00, 24 June 2013 (UTC)
  • Item 5: The updated text reads: "In 1921 the Convention of the Metre was revised and the mandate of the CGPM was extended to provide standards for all units of measure, not just mass and length. In the ensuing years the CGPM took on responsibility for providing standards of time (1956), electric current (1946), temperature (1948), molar mass (1971) and luminosity (1946)." Martinvl (talk) 15:00, 24 June 2013 (UTC)

The issues raised in the second set of comments have been handled as follows:

  • Item 1: Done - diffs here. Martinvl (talk) 10:39, 25 June 2013 (UTC)
  • Item 2: Done. Martinvl (talk) 16:16, 24 June 2013 (UTC)
  • Item 3: The intro paragraph to the section now reads "The current (2008)1 and proposed (2011)2 definitions are given below." Martinvl (talk) 16:16, 24 June 2013 (UTC)
  • Item 4: Discussion on the impact of the changes on the ampere has been overhauled and citations provided. Martinvl (talk) 16:16, 24 June 2013 (UTC)
  • Item 5: Section Proposed redefinition of SI base units#Impact on reproducibility has been modified - citations were found that paralleled work which could be held to be WP:OR. Martinvl (talk) 10:42, 25 June 2013 (UTC)
  • Item 6: Final section has been rewritten - the comments made by the reviewer no longer apply, but the whole section needs to be reviewed.

As each item is addressed, it will be signed.

Martinvl (talk) 14:45, 24 June 2013 (UTC)

Also note the contradiction "In 1960 the metre was redefined in terms of the speed of light, making it derivable from nature" in the lead vs "Similarly, the 17th CGPM (1983) replaced the 1960 definition of the metre[Note 2] with one where the metre is derived from the speed of light" in the background section. Adabow (talk) 06:12, 26 June 2013 (UTC)

Thank you for spotting this - I have corrected it.
When trying to find out more about Leonard, I discovered that a lot more discussion material had become available, so I am rewriting the final section which I am calling "Discussion" rather than "Criticism". I hope to have it in place in a few days. Martinvl (talk) 06:44, 26 June 2013 (UTC)
Sounds great! Take your time - no rush. Adabow (talk) 07:38, 26 June 2013 (UTC)
Hi Adabow,
I have now completed my revisions following your initial review and when you are ready, I would be grateful if you could assess my latest offerings. Martinvl (talk) 20:49, 3 July 2013 (UTC)
There is still no explanation for who Leonard is. Ditto for Chyla. When someone is mentioned, there first name should be included in the first instance. If the first names are not known, then please at least give initials. Affiliation should be given as well. Adabow (talk) 23:27, 4 July 2013 (UTC)
Done. Reading between the lines Chyla appears to be a freelancer so his affiliation carries no weight, however the journal where this paper was published referees its papers, so that has been included in the text (complete with Wikilink).

OK, everything looks good to me now. Passing. Well done. Adabow (talk) 10:45, 5 July 2013 (UTC)

Diagram description[edit]

the diagram for current definitions of SI units claims in its description that a meter is defined as the distance traveled by light in 1 second. according to the article on the meter it is equal to 1/299,792,458 of this value, and the claim is sourced. I suggest the source be reused here and the information corrected. — Preceding unsigned comment added by 96.245.192.47 (talk) 20:13, 14 September 2014 (UTC)

The caption doesn't say that the metre is defined as the distance traveled by light in a second, it says "in term of". The point is that it's defined in terms of distance traveled. But you're right, it's clumsy enough to be potentially misleading. I'll try tweaking it (though without putting in the precise value because that isn't the point) - see what you think. NebY (talk) 23:17, 14 September 2014 (UTC)

gram[edit]

maybe it's time to change kg to gram? — Preceding unsigned comment added by 134.7.190.150 (talk) 10:26, 23 June 2015 (UTC)