Talk:kelvin

Tea room discussion
As a mechanical engineer with a B.S. and M.S. from MIT with a specialization in Thermodynamics, I must emphatically assert that the usage of the Kelvin scale when spoken or written is always singular (e.g. "77 kelvin"). This is confirmed by Wiktionary "...[kelvin] (usually as postpositioned adjective) A unit for a specific temperature on the Kelvin scale.

Ice melts above 273.15 kelvin. Water boils above 373.15 kelvin."

The temperature unit. I might come close to understanding this, finally, in part. But, I still don't understand the relationship of the official definition (which we appropriately parrot as sense 1) and the 2 senses I added based on the WP article's distinction between the interval kelvin and the specific temperature level. There are at least two distinct common usages: "372.12 kelvin is the boiling point of water." (specific temperature) and "100 kelvins" is the interval over which water is liquid at 1 atmosphere." {interval). The second allows for a plural. The first does not. But I'm not sure that the first should be considered a noun. degree Kelvin is obsolete usage, BTW. DCDuring TALK 18:07, 29 June 2008 (UTC)
 * How is degree Kelvin obsolete? By "obsolete", we usually mean that not only is it no longer in use, but also that modern speakers would not understand the expression.  Do you really believe that people today do not understand the meaning of degree Kelvin? --EncycloPetey 19:59, 29 June 2008 (UTC)
 * I don't know how we handle the pronouncements of scientific authorities. We seem to give their sayings great weight selectively, but not systematically. Perhaps we need a tag for terms that are part of an official scientific vocabulary. There are certainly taxonomic names that are obsolete, for example, but may still be used in gardening books. In what sense is that obsolete? DCDuring TALK 23:10, 29 June 2008 (UTC)
 * They would be obsolete in the sense that even taxonomists would probably have to look them up in order to determine the current name. The old name is obsolete because it isn't in current use and is meaningless to most people.  This is not the same as degree Kelvin which, even if it may not be in regular current use (though I disagree with that), it certainly doesn't have to be looked up to be understood. --EncycloPetey 16:56, 30 June 2008 (UTC)


 * I don't disagree with a word of what you have said, but I am wondering what you recommend for accommodating the sense in which is has been obsolete since 1968 per the CGBM. Do we treat a scientific nomenclature body as we would a national language academy? I am unfamiliar with whether we or any wiktionary assign any weight whatsoever to a national academy or whether there would be grounds for treating a scientific body differently. DCDuring TALK 17:09, 30 June 2008 (UTC)


 * In English anyway, it is attestation which is most important. If the term is becoming obsolete in practice, then it can be labelled nonstandard, or dated.  The status according to an international standards body should be mentioned separately in a usage note (and this status is distinct from our dictionary “obsolete”). —Michael Z. 2008-06-30 17:47 z 


 * I agree that "deprecated" != "obsolete". We have, but it's only used in 50 main-namespace entries. I used it for a bit, personally, but stopped when I discovered that a number of editors (and IIRC even a few commenters at Feedback) were mistaking the meaning and thinking that we at Wiktionary were the ones proscribing. A usage note is probably the way to go. —Ruakh TALK 02:43, 1 July 2008 (UTC)


 * There is constant deprecation of terminology in scientific communities. It recurs so often that I would think that it would warrant a status indication of some kind that did not require editors to reinvent the proverbial wheel at each instance.
 * The difference between scientific language and ordinary language seems to be that the identity, legitimacy, and value of the authoritative body are fairly clear. The force of the deprecation is fairly strong, presumably mostly through the editorial review process at academic journals as well as other kinds of peer pressure. IUPAC, CGBM, and other bodies seem to matter.
 * Ought we not have a tag for this specific purpose? Should it say "(deprecated by BIPM)" in this instance ? DCDuring TALK 04:44, 1 July 2008 (UTC)


 * I think the second definition is not quite correct, or at least unclear. 100 kelvin is analogous to 100 Celsius (it may be an abbreviation of the non-standard 100 degrees Kelvin), and should properly be capitalized: 100 Kelvin. —Michael Z. 2008-06-29 20:51 z 
 * It may well be unclear. Since 1968 there is no use of the unit kelvin that is properly capitalized, according to my consultation of the website that reports the decision of the CGBM (I think). "degrees Celsius" = "kelvins" in the interval sense. "degrees Celsius" corresponds to "kelvin" in the specific temperature sense. The convenient, nearly definitive source seems to be here, (at the BIPM).

By the way, the second example in Kelvin scale seems wrong. The Kelvin scale is a technical concept, not a piece of lab equipment. Any objection to removing it? —Michael Z. 2008-06-29 21:15 z 
 * Remove it you like. I'm betting it is used as example indicates. The world of science is backed up be a world of measurement by specific instruments. I think it would be an example of metonymy, if I remember my nyms correctly. 21:48, 29 June 2008 (UTC)


 * A Google search on ("kelvin scales" calibration -celsius) resulted in about 25 hits. I checked a few of them, but they did not offer any proof that Kelvin scale is used to mean an instrument. I did two other searches (including Google images) and could not find anything that looked like a Kelvin scale other than thermometers or paper guides showing gradations. I do agree that it would seem that such usage exists, but I did not find any. Wakablogger 21:54, 29 June 2008 (UTC)Wakablogger


 * I had a look at all of those search results (12 unique links). Most refer to “Fahrenheit and Kelvin scales,” and some are mistakes.  Not one refers to an instrument such as a Kelvin scale, although three use the phrase "generally an observing block should be self contained, and be able to be calibrated independently, although it might use system calibrations e.g. Jy/Kelvin scales and bandpass," which I assume refers in plural to the Jansky and Kelvin scales.


 * I'm surprised at how few uses there were, but even if used as in the example, it is referring to something else: either an instrument or an indicator, rather than the sequence of temperature intervals. I'll remove the example, and I'll also try to improve the definition, so that it doesn't use the word scale. —Michael Z. 2008-06-29 22:30 z 


 * Thanks for the help. IANA physicist or chemist. DCDuring TALK 22:45, 29 June 2008 (UTC)

Unrelated to dictionary use
Just came by as a physicist, stumpling upon the use of 273.16 K as the melting point of water which is a common mistake, so took the time to remove it here, to keep it from propagating further on the net.

As I am not a regular editor, I won't see any comments to this, hence the potential need for this explanation.

The melting temperatures of water is 273.15 K, and that has not changed. It was earlier used to define the Kelvin scale.

The value 273.16 K (or 0.01ºC) is waters triple point, which is now used to define the Kelvin scale (hence the mixup, I guess), but that does not make it the melting point of water.

I also changed the boiling point to 373.15, just to keep it simple.

- Richard Tøpholm 188.180.111.132 13:42, 24 July 2012 (UTC)