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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." — Preceding unsigned comment added by 2601:6:3280:483:4593:DD0:2C31:EA0D ( talk) 19:27, 2 May 2015 (UTC)
I have a proposal and am interested in what others think. I note that the BIMP and the NIST seem to have both ducked the issue of plural usage of kelvin when reporting temperatures. This Kelvin article currently ducks the issue too and the conspicuous absence sticks out like sore thumb. This article tells that kelvin in its plural form is kelvins, but it currently entirely avoids the topic of plural usage. From what I can see, plural usage is currently a free-for-all. It seems that intervals, e.g., “the difference between our two readings was 50 kelvins” is most commonly expressed using the plural form. This makes sense to me and and seems consistent with the rules of English usage. However, it seems that both forms are used in the expression of specific temperature values. One can as easily find "a temperature of 300 kelvin" as one can find "a temperature of 300 kelvins." I just now googled on sun "5800 kelvin" and got 963 hits. I got 458 hits on sun "5800 kelvins". I'm sure Wikipedia contributors have opinions as to what is the “proper” way to express temperatures but personal opinions are a dime a dozen. I wonder if any prominent scientific journals have specific editorial guidelines on this issue. So…
I've got a suggestion and a question. Perhaps this article should address the issue of plural usage by noting that both forms are currently used and there is no officially endorsed form. As regards my question, does anyone know of a suggested editorial practice by a reputable scientific publishing organization regarding the expression of kelvin temperatures? Greg L ( my talk) 05:22, 4 April 2007 (UTC)
We don't talk about "centigrades" or "Fahrenheits" when giving temperatures, so why should we say "Kelvins?" Seems to me that the unit in all of these cases is the degree; the terms centigrade, Fahrenheit, Kelvin, etc. simply give the point of reference from which the measurement of degrees starts. True, since the size of a centigrade degree is different from that of a Fahrenheit degree, there is some justification for recognizing that uniqueness in an abbreviated form by saying "Kelvins," but it comes down to a personal preference, I suppose, for the "degrees Kelvin" form. As to capital letters, I think it's good to remember that Kelvin, Ohm, Volta, etc., were people--yes, it's nice to honor them, but it's also helpful to recall that they were human, and we are dealing with results of human endeavors--i.e., they might have made some wrong assumptions, and we should always be careful of following blindly. Personally, I am dead set against counting instances and going with the majority on ANY question whatsoever. Remember, half the folks out there are by definition below average. :) As a historian, I have NEVER tried to settle a dispute by counting the number of sources on either side of the question. The question is how good the sources are, not how many idjots took the easy way out and copied a bad source without checking it. Terry J. Carter ( talk) 18:25, 4 July 2008 (UTC)
"over a wide temperature range from a few kelvins to above 550 K."
There seems to be an issue with the history of the Kelvin scale, which I reverted. The 1848 paper does deal with the need for an absolute thermometric scale, so I'm not sure what the point of the edit was. There were also some typoes present, and items removed without explanation. So, let's discuss what is thought to be needed before reinstating this change. Tarl N. ( discuss) 03:16, 13 June 2019 (UTC)
I simply thought I would share what I have learned:
The redefinition of SI results in the triple point of water now becoming an empirically determined value. I think the current lead is perhaps misleading in that it could be read to indicate that the triple point of water is still exactly 0.01 Celsius, when this is no longer the case. Thus I changed the lead. Please let me know if you feel that this is incorrect. 2601:184:407F:8921:646B:30F2:10C3:559E ( talk) 03:10, 7 July 2019 (UTC)
Do you think we should create a section on the mathematical implications of assigning an exact value the the Boltzmann constant?
Do you think we should create a section on the the motivation for creating an absolute temperature scale at all, rather than sticking with scales that have some other starting point? This has the potential to get into puff piece territory, but I could also imagine this being one of the main questions people have when looking this subject up. Ava Eva Thornton ( talk) 07:29, 18 February 2022 (UTC)
I don't see why there should be a (rather lengthy) section on 1 Kelvin in this article. More appropriately it should be in a separate article, much like
absolute zero.
—DIV (
137.111.13.4 (
talk) 03:47, 9 May 2022 (UTC))
The user Ava Eva Thornton ( talk · contribs) added a huge volume of content in this article, not all of it useful. Compare what the article used to look like vs. what it looks like now. While, some the content is mostly tangential, usually quantitative information. I have already deleted a section that was purely WP:OR that added no useful information about the 2019 definition. The "Multiples" section is mostly WP:IINFO, and I recommend either converting it into a table like Metre#SI prefixed forms of metre, or deleting it outright; "1 kelvin" should probably be deleted for the same reason. – LaundryPizza03 ( d c̄) 19:55, 13 July 2022 (UTC)
Multiplessection should simply go away. The
1 Kelvinsection has interesting information, but isn't specific to the Kelvin scale, so should probably be moved to another article. Tarl N. ( discuss) 20:26, 13 July 2022 (UTC)
1 Kelvinsection probably belongs in the Absolute zero#Very low temperatures section, which it at least partially overlaps. Tarl N. ( discuss) 20:33, 13 July 2022 (UTC)
The Conversion Table is placed in (adjacent to) the "Practical uses" section, but has nothing to do with the section's content. A better placement would be desirable.
189.250.250.12 ( talk) 13:16, 12 September 2022 (UTC) baden k.
In the intro, can it be made immediately obvious that a characteristic of Kelvin is that its lowest possible value is 0, because it is tied to kinetic energy? i.e. Kelvin's values range from 0 on upwards; there is never a negative Kelvin value (if this is true). Such basic things about the nature and usage and consequences of concepts are nice to make immediately clear, for anyone who doesn't really need to know more than that, but does need to know and understand such implications for usage. And then anyone who wants to go further for the sake of knowledge or the nuances of those reasons can delve into the further details.
I'll write what I might suggest for such an addition later, if I remember. GabeGibler ( talk) 23:25, 17 February 2023 (UTC)
@ NebY I don't think your lead structure is "much-improved". My two-paragraph structure has a simple, logical structure: one paragraph for the current definition and one paragraph for the historical definitions. This makes the key points clear. In contrast, your structure is fragmented - the historical context abruptly ends and then switches to discussing the 2019 redefinition in a new paragraph. Putting the 2019 redefinition using the Boltzmann at the start of a new paragraph is confusing to readers as they wonder why this is a new topic and how it is related to kelvins. In contrast, my second paragraph seamlessly integrates all of the historical definitions without disrupting the flow of the text. Two paragraphs is also more concise than 3 - following your logic, every sentence would be in its own paragraph because these "brief paragraphs" would somehow make it less intimidating. But of course this is flawed as breaking up paragraphs with random breaks makes it less readable and more intimidating.
My structure introduces the precise, current definition of the scale early, following MOS:LEADSENTENCE: "If its subject is definable, then the first sentence should give a concise definition." (Per Wikipedia:Wikipedia_is_not_a_dictionary#Good_definitions it is actually two sentences with two definitions, as the kelvin and Kelvin scale are highly related topics). In contrast, if someone needs to identify the current definition of the Kelvin scale in your structure, they would have to look at the beginning and end of the first paragraph and also search through the end of the third paragraph. This disjointed definition is not suitable for grasping the concept of the kelvin. It is not accessible, not early, and not clear. Mathnerd314159 ( talk) 18:36, 2 May 2024 (UTC)
References
It is even more important here than in the rest of the article that the text be accessible. Editors should avoid lengthy paragraphs and overly specific descriptions – greater detail is saved for the body of the article.NebY ( talk) 18:01, 3 May 2024 (UTC)
I'm not well versed in the subject myself except for it's practical importance, in that, at very cold temperatures just as in very deep vacuums relative scales tend to break down, hence having an absolute scale becomes a necessity then. So I don't have have much input to give beyond advice about writing in general. But along those lines I would make this suggestion: the last few days the article has become very unstable, which can be confusing or even frustrating for the reader. Perhaps it would be better to finish this discussion and hammer out all the details first, and when everyone has come to a consensus, then implement the changes to the article. We can copy/paste it right here and do all the wordsmithing until it's just right, without disrupting all those readers out there. Not to mention, it's hard to discuss something when that something is in constant flux, (see my last comment). To discuss, it's important to give people time to respond.
That said, it's refreshing to see people actually discussing a subject in a collaborative manner rather than a combative one, for a change, so thanks for that. Zaereth ( talk) 22:15, 3 May 2024 (UTC)
Combining some of the recent improvements with some earlier ideas, I'd like to float the following draft; it's not perfect (no Wikipedia lead is ever perfect) but you'll recognise some of the principles from the discussion above. I've removed the refs for two reasons: they make talk-page drafting awkward, especially as many will be unresolved, and it's not actually necessary to source a lead when it's summarising sourced content, so we may do without them anyway.
Draft |
---|
The kelvin, symbol K, is the
base unit of measurement for
temperature in the
International System of Units (SI). The Kelvin scale is an
absolute
temperature scale that starts from 0 K as the coldest possible temperature,
absolute zero. It is named after the nineteenth-century British scientist
Lord Kelvin who first developed it, and was formally added to the International System of Units in 1954.
The Kelvin scale was developed from the Celsius scale (symbol °C). A change of 1 K exactly equals a change of 1 °C, but absolute zero, -273.15 °C, is 0 K. Any temperature in degrees Celsius can be converted to kelvin by adding 273.15. The Celsius, Fahrenheit, and Rankine scales are now defined in terms of the Kelvin scale. The kelvin itself is now defined in terms of energy by setting the Boltzmann constant to exactly 1.380649×10−23 joules per kelvin; every 1 K change of thermodynamic temperature corresponds to a thermal energy change of exactly 1.380649×10−23 J. |
NebY ( talk) 17:00, 4 May 2024 (UTC)
The stable (April 30th) section on "2019 redefinition" said:
"The unit J/K is equal to kg⋅m2⋅s−2⋅K−1, where the kilogram, metre and second are defined in terms of the Planck constant, the speed of light, and the duration of the caesium-133 ground-state hyperfine transition respectively. Thus, this definition depends only on universal constants, and not on any physical artifacts as practiced previously."
(Note I did do some rearrangement and tweaks to that section, which is why I've copied that stable version here.)
Out of curiosity, I looked at Caesium standard#Summary which gives an expression of the kelvin in terms of the SI defining constants (h, ΔνCs, and k) to be:
1 kelvin = 13.80649/6.09110229711386655 h ΔνCs/k
I want to put this into the "2019 redefinition" section, because it gives exactly what kelvin is in terms of the defining constants. Currently kelvin's article only provides the indirect definition by putting kelvin in the denominator of kB ≝ 1.380649×10−23 J/K. So I'm thinking to make kelvin's article a little more about kelvin (this article is titled "kelvin" and not "Boltzmann constant"), I'd like to add this expression to the "2019 redefinition" section (and maybe also in the "extradata2" field of its infobox unit). But per Zaereth's request to slow down editing the page directly, I'm posting in this talk first. Em3rgent0rdr ( talk) 00:25, 4 May 2024 (UTC)
This is the
talk page for discussing improvements to the
Kelvin article. This is not a forum for general discussion of the article's subject. |
Article policies
|
Find sources: Google ( books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL |
This
level-4 vital article is rated B-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | |||||||||||
|
|
||
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." — Preceding unsigned comment added by 2601:6:3280:483:4593:DD0:2C31:EA0D ( talk) 19:27, 2 May 2015 (UTC)
I have a proposal and am interested in what others think. I note that the BIMP and the NIST seem to have both ducked the issue of plural usage of kelvin when reporting temperatures. This Kelvin article currently ducks the issue too and the conspicuous absence sticks out like sore thumb. This article tells that kelvin in its plural form is kelvins, but it currently entirely avoids the topic of plural usage. From what I can see, plural usage is currently a free-for-all. It seems that intervals, e.g., “the difference between our two readings was 50 kelvins” is most commonly expressed using the plural form. This makes sense to me and and seems consistent with the rules of English usage. However, it seems that both forms are used in the expression of specific temperature values. One can as easily find "a temperature of 300 kelvin" as one can find "a temperature of 300 kelvins." I just now googled on sun "5800 kelvin" and got 963 hits. I got 458 hits on sun "5800 kelvins". I'm sure Wikipedia contributors have opinions as to what is the “proper” way to express temperatures but personal opinions are a dime a dozen. I wonder if any prominent scientific journals have specific editorial guidelines on this issue. So…
I've got a suggestion and a question. Perhaps this article should address the issue of plural usage by noting that both forms are currently used and there is no officially endorsed form. As regards my question, does anyone know of a suggested editorial practice by a reputable scientific publishing organization regarding the expression of kelvin temperatures? Greg L ( my talk) 05:22, 4 April 2007 (UTC)
We don't talk about "centigrades" or "Fahrenheits" when giving temperatures, so why should we say "Kelvins?" Seems to me that the unit in all of these cases is the degree; the terms centigrade, Fahrenheit, Kelvin, etc. simply give the point of reference from which the measurement of degrees starts. True, since the size of a centigrade degree is different from that of a Fahrenheit degree, there is some justification for recognizing that uniqueness in an abbreviated form by saying "Kelvins," but it comes down to a personal preference, I suppose, for the "degrees Kelvin" form. As to capital letters, I think it's good to remember that Kelvin, Ohm, Volta, etc., were people--yes, it's nice to honor them, but it's also helpful to recall that they were human, and we are dealing with results of human endeavors--i.e., they might have made some wrong assumptions, and we should always be careful of following blindly. Personally, I am dead set against counting instances and going with the majority on ANY question whatsoever. Remember, half the folks out there are by definition below average. :) As a historian, I have NEVER tried to settle a dispute by counting the number of sources on either side of the question. The question is how good the sources are, not how many idjots took the easy way out and copied a bad source without checking it. Terry J. Carter ( talk) 18:25, 4 July 2008 (UTC)
"over a wide temperature range from a few kelvins to above 550 K."
There seems to be an issue with the history of the Kelvin scale, which I reverted. The 1848 paper does deal with the need for an absolute thermometric scale, so I'm not sure what the point of the edit was. There were also some typoes present, and items removed without explanation. So, let's discuss what is thought to be needed before reinstating this change. Tarl N. ( discuss) 03:16, 13 June 2019 (UTC)
I simply thought I would share what I have learned:
The redefinition of SI results in the triple point of water now becoming an empirically determined value. I think the current lead is perhaps misleading in that it could be read to indicate that the triple point of water is still exactly 0.01 Celsius, when this is no longer the case. Thus I changed the lead. Please let me know if you feel that this is incorrect. 2601:184:407F:8921:646B:30F2:10C3:559E ( talk) 03:10, 7 July 2019 (UTC)
Do you think we should create a section on the mathematical implications of assigning an exact value the the Boltzmann constant?
Do you think we should create a section on the the motivation for creating an absolute temperature scale at all, rather than sticking with scales that have some other starting point? This has the potential to get into puff piece territory, but I could also imagine this being one of the main questions people have when looking this subject up. Ava Eva Thornton ( talk) 07:29, 18 February 2022 (UTC)
I don't see why there should be a (rather lengthy) section on 1 Kelvin in this article. More appropriately it should be in a separate article, much like
absolute zero.
—DIV (
137.111.13.4 (
talk) 03:47, 9 May 2022 (UTC))
The user Ava Eva Thornton ( talk · contribs) added a huge volume of content in this article, not all of it useful. Compare what the article used to look like vs. what it looks like now. While, some the content is mostly tangential, usually quantitative information. I have already deleted a section that was purely WP:OR that added no useful information about the 2019 definition. The "Multiples" section is mostly WP:IINFO, and I recommend either converting it into a table like Metre#SI prefixed forms of metre, or deleting it outright; "1 kelvin" should probably be deleted for the same reason. – LaundryPizza03 ( d c̄) 19:55, 13 July 2022 (UTC)
Multiplessection should simply go away. The
1 Kelvinsection has interesting information, but isn't specific to the Kelvin scale, so should probably be moved to another article. Tarl N. ( discuss) 20:26, 13 July 2022 (UTC)
1 Kelvinsection probably belongs in the Absolute zero#Very low temperatures section, which it at least partially overlaps. Tarl N. ( discuss) 20:33, 13 July 2022 (UTC)
The Conversion Table is placed in (adjacent to) the "Practical uses" section, but has nothing to do with the section's content. A better placement would be desirable.
189.250.250.12 ( talk) 13:16, 12 September 2022 (UTC) baden k.
In the intro, can it be made immediately obvious that a characteristic of Kelvin is that its lowest possible value is 0, because it is tied to kinetic energy? i.e. Kelvin's values range from 0 on upwards; there is never a negative Kelvin value (if this is true). Such basic things about the nature and usage and consequences of concepts are nice to make immediately clear, for anyone who doesn't really need to know more than that, but does need to know and understand such implications for usage. And then anyone who wants to go further for the sake of knowledge or the nuances of those reasons can delve into the further details.
I'll write what I might suggest for such an addition later, if I remember. GabeGibler ( talk) 23:25, 17 February 2023 (UTC)
@ NebY I don't think your lead structure is "much-improved". My two-paragraph structure has a simple, logical structure: one paragraph for the current definition and one paragraph for the historical definitions. This makes the key points clear. In contrast, your structure is fragmented - the historical context abruptly ends and then switches to discussing the 2019 redefinition in a new paragraph. Putting the 2019 redefinition using the Boltzmann at the start of a new paragraph is confusing to readers as they wonder why this is a new topic and how it is related to kelvins. In contrast, my second paragraph seamlessly integrates all of the historical definitions without disrupting the flow of the text. Two paragraphs is also more concise than 3 - following your logic, every sentence would be in its own paragraph because these "brief paragraphs" would somehow make it less intimidating. But of course this is flawed as breaking up paragraphs with random breaks makes it less readable and more intimidating.
My structure introduces the precise, current definition of the scale early, following MOS:LEADSENTENCE: "If its subject is definable, then the first sentence should give a concise definition." (Per Wikipedia:Wikipedia_is_not_a_dictionary#Good_definitions it is actually two sentences with two definitions, as the kelvin and Kelvin scale are highly related topics). In contrast, if someone needs to identify the current definition of the Kelvin scale in your structure, they would have to look at the beginning and end of the first paragraph and also search through the end of the third paragraph. This disjointed definition is not suitable for grasping the concept of the kelvin. It is not accessible, not early, and not clear. Mathnerd314159 ( talk) 18:36, 2 May 2024 (UTC)
References
It is even more important here than in the rest of the article that the text be accessible. Editors should avoid lengthy paragraphs and overly specific descriptions – greater detail is saved for the body of the article.NebY ( talk) 18:01, 3 May 2024 (UTC)
I'm not well versed in the subject myself except for it's practical importance, in that, at very cold temperatures just as in very deep vacuums relative scales tend to break down, hence having an absolute scale becomes a necessity then. So I don't have have much input to give beyond advice about writing in general. But along those lines I would make this suggestion: the last few days the article has become very unstable, which can be confusing or even frustrating for the reader. Perhaps it would be better to finish this discussion and hammer out all the details first, and when everyone has come to a consensus, then implement the changes to the article. We can copy/paste it right here and do all the wordsmithing until it's just right, without disrupting all those readers out there. Not to mention, it's hard to discuss something when that something is in constant flux, (see my last comment). To discuss, it's important to give people time to respond.
That said, it's refreshing to see people actually discussing a subject in a collaborative manner rather than a combative one, for a change, so thanks for that. Zaereth ( talk) 22:15, 3 May 2024 (UTC)
Combining some of the recent improvements with some earlier ideas, I'd like to float the following draft; it's not perfect (no Wikipedia lead is ever perfect) but you'll recognise some of the principles from the discussion above. I've removed the refs for two reasons: they make talk-page drafting awkward, especially as many will be unresolved, and it's not actually necessary to source a lead when it's summarising sourced content, so we may do without them anyway.
Draft |
---|
The kelvin, symbol K, is the
base unit of measurement for
temperature in the
International System of Units (SI). The Kelvin scale is an
absolute
temperature scale that starts from 0 K as the coldest possible temperature,
absolute zero. It is named after the nineteenth-century British scientist
Lord Kelvin who first developed it, and was formally added to the International System of Units in 1954.
The Kelvin scale was developed from the Celsius scale (symbol °C). A change of 1 K exactly equals a change of 1 °C, but absolute zero, -273.15 °C, is 0 K. Any temperature in degrees Celsius can be converted to kelvin by adding 273.15. The Celsius, Fahrenheit, and Rankine scales are now defined in terms of the Kelvin scale. The kelvin itself is now defined in terms of energy by setting the Boltzmann constant to exactly 1.380649×10−23 joules per kelvin; every 1 K change of thermodynamic temperature corresponds to a thermal energy change of exactly 1.380649×10−23 J. |
NebY ( talk) 17:00, 4 May 2024 (UTC)
The stable (April 30th) section on "2019 redefinition" said:
"The unit J/K is equal to kg⋅m2⋅s−2⋅K−1, where the kilogram, metre and second are defined in terms of the Planck constant, the speed of light, and the duration of the caesium-133 ground-state hyperfine transition respectively. Thus, this definition depends only on universal constants, and not on any physical artifacts as practiced previously."
(Note I did do some rearrangement and tweaks to that section, which is why I've copied that stable version here.)
Out of curiosity, I looked at Caesium standard#Summary which gives an expression of the kelvin in terms of the SI defining constants (h, ΔνCs, and k) to be:
1 kelvin = 13.80649/6.09110229711386655 h ΔνCs/k
I want to put this into the "2019 redefinition" section, because it gives exactly what kelvin is in terms of the defining constants. Currently kelvin's article only provides the indirect definition by putting kelvin in the denominator of kB ≝ 1.380649×10−23 J/K. So I'm thinking to make kelvin's article a little more about kelvin (this article is titled "kelvin" and not "Boltzmann constant"), I'd like to add this expression to the "2019 redefinition" section (and maybe also in the "extradata2" field of its infobox unit). But per Zaereth's request to slow down editing the page directly, I'm posting in this talk first. Em3rgent0rdr ( talk) 00:25, 4 May 2024 (UTC)