Talk:Kilogram

Reference 3 Out of Date?

I was looking at reference 3 and it appears that this link no longer works. Can this be changed to https://link.springer.com/article/10.1007/s11018-019-01648-4 or does it need to be a PDF since springer is pay-walled for some.

Use "an", not "a", prior to an initialism based on how it is pronounced.

Example: "SI" is pronounced "ess eye". Therefore:

Correct: an SI prefix.

Incorrect: a SI prefix.

Reference: here. There are lots of additional references. -Arch dude (talk) 14:51, 25 July 2023 (UTC)

@1TWO3Writer: Thanks for your efforts. This is a trivial issue, but I thought you would like to see the reference. -Arch dude (talk) 15:03, 25 July 2023 (UTC)

Oh, I see, thanks! TIL. 123Writer ^talk 15:07, 25 July 2023 (UTC)

Planck constant is defined, not determined.

An editor added an extensive section on determining the Plank constant. I reverted it because this is not longer how it works. If we need such a section at all, it will need some context first. After 2019, when you "measure" the Planck constant, you are actually calibrating your measurement device. -Arch dude (talk) 16:45, 14 October 2023 (UTC)

Sorry I think you misread the text you reverted. The first sentence:

"The value of the kilogram is determined by measuring the Planck constant and adjusting the kilogram value to ensure the constant returns to its defined value."

Since 2019 the kilogram is defined in terms of the Planck constant. Thus to determine the kilogram you apply the technology previously used to determine the Planck constant.

To be sure, that text was in Planck constant and maybe it needs more work and I think it is too long. But the current article has only one sentence on how the value of the kilogram is determined. Johnjbarton (talk) 14:49, 15 October 2023 (UTC)

@Johnjbarton: the value of the kilogram is not "determined". It is defined. No laboratory procedure will change the value of the kilogram. The term you are looking for is "realization". There may be several ways to create a realization: i.e., actually measure the mass of something based on the definition. It's possible that each of the old ways to measure Plank's constant is now a way to create a realization of a mass measurement device: I don't know. I think this is far more than pedantry. It goes to the heart of the new definition of the kilogram and the way this new definition is to be applied in the real world. -Arch dude (talk) 20:35, 15 October 2023 (UTC)

No need to lecture me, esp. in a paragraph where you say "I don't know".

The article needs work to explain how the value of a kilogram is now measured, determined, or realized, your choice.

This ref covers the details: Wolfgang Ketterle, Alan O. Jamison; An atomic physics perspective on the kilogram’s new definition. Physics Today 1 May 2020; 73 (5): 32–38. https://doi.org/10.1063/PT.3.4472

Unfortunately it's not very clearly written.

Since you did not like my addition, what do you propose? Johnjbarton (talk) 01:34, 16 October 2023 (UTC)

@Johnjbarton:I'm sorry you saw that as "lecturing" you, and I apologize. I did not wish to offend, and I realize that you are genuinely trying to improve the article. I think we do need a section on the "realization" of the definition. I recommend we start with the one described by BIPM:

• "Mise en pratique for the definition of the kilogram in the SI". BIPM.org. July 7, 2021. Retrieved February 18, 2022.

If you can find any other descriptions of "realizations" using other techniques, then we can add them also. In particular, there are now commercially-available devices using an approach similar to the Kibble balance. They are used by pharmaceutical companies today. They are described in the Kibble balance article. This is somewhat similar to the commercial laboratory devices that were developed for the second (atomic clocks) and for the meter (interferometers) when those units were redefined. -Arch dude (talk) 13:36, 16 October 2023 (UTC)

Date format

I reverted this edit which changed the date format to mdy contrary to the style guide at MOS:DATERET. My revert was reverted with the edit summary The data format has been set since at least 2014. Please discuss in the Talk:Kilogram if you feel strongly this should change. I would prefer if we used the dmy format since it is a more international format used by most of the world. And I feel strongly about this case since this was the original format used in the article and was changed without a consensus. Thank you. Pynappel (talk) 18:52, 26 December 2023 (UTC)

The mixture of UK spelling with US dates is weird. I would support a change to either UK spelling + UK date or US spelling + US date. I don't mind which. Dondervogel 2 (talk) 19:09, 26 December 2023 (UTC)