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::Following on from this, every source that I can remember that has spoken historically about the Planck unit system has made it fairly clear that the electromagnetic dimension is not part of the system, either as Planck defined it originally or its modern variant with the reduced Planck constant. Currently, what is in the article amounts to what can be found in some primary sources as a definition for convenience, which it seems to me should not be reported here. Consequently, I think the Planck charge should be removed as "a Planck unit" and its inclusion limited to a mention of its status in this regard. Should anyone have references that contradict this perspective, these would be welcome. —[[User_talk:Quondum|Quondum]] 14:25, 21 May 2020 (UTC) |
::Following on from this, every source that I can remember that has spoken historically about the Planck unit system has made it fairly clear that the electromagnetic dimension is not part of the system, either as Planck defined it originally or its modern variant with the reduced Planck constant. Currently, what is in the article amounts to what can be found in some primary sources as a definition for convenience, which it seems to me should not be reported here. Consequently, I think the Planck charge should be removed as "a Planck unit" and its inclusion limited to a mention of its status in this regard. Should anyone have references that contradict this perspective, these would be welcome. —[[User_talk:Quondum|Quondum]] 14:25, 21 May 2020 (UTC) |
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:::The Planck charge is very important and it is a base (non-derived) unit. It is actually a very peculiar unit, since it is the only Planck unit that does not depend on the gravitational constant, so its value is known with high precision (and before the last changes in [[International System of Units|SI]] it was the only Planck unit whose value was exact by definition). It establishes a relationship between electric and gravitational force: take two flea eggs, charge them with <math> \frac{e}{\sqrt{\alpha}} </math> of positive charge each (i.e., a Planck charge, value known nearly exactly – as for the fact that the value is not an integer number of elementary charges, it is very easy to find the right workaround), if they don't repel each other because their gravitational force balances exactly their electric repulsion you have got two Planck masses – and you have got them without having to know the exact value of [[gravitational constant|G]]. Furthermore the Planck charge appears as a limit in the [[Reissner–Nordström metric]] for a charged Planck black hole. The original Planck units were different than the ones used today – I have posted a table in the article: if you feel like removing the Planck charge just because it was not present in the original proposal written by Planck you should also multiply all other units by <math>\sqrt{2 \pi}</math> (but then this article will finally be completely useless). --[[User:Grufo|Grufo]] ([[User talk:Grufo|talk]]) 15:36, 21 May 2020 (UTC) |
:::The Planck charge is very important and it is a base (non-derived) unit. It is actually a very peculiar unit, since it is the only Planck unit that does not depend on the gravitational constant, so its value is known with high precision (and before the last changes in [[International System of Units|SI]] it was the only Planck unit whose value was exact by definition). It establishes a relationship between electric and gravitational force: take two flea eggs, charge them with <math> \frac{e}{\sqrt{\alpha}} </math> of positive charge each (i.e., a Planck charge, value known nearly exactly – as for the fact that the value is not an integer number of elementary charges, it is very easy to find the right workaround), if they don't repel each other because their gravitational force balances exactly their electric repulsion you have got two Planck masses – and you have got them without having to know the exact value of [[gravitational constant|G]]. Furthermore the Planck charge appears as a limit in the [[Reissner–Nordström metric]] for a charged Planck black hole. The original Planck units were different than the ones used today – I have posted a table in the article: if you feel like removing the Planck charge just because it was not present in the original proposal written by Planck you should also multiply all other units by <math>\sqrt{2 \pi}</math> (but then this article will finally be completely useless). --[[User:Grufo|Grufo]] ([[User talk:Grufo|talk]]) 15:36, 21 May 2020 (UTC) |
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::::It shows up in this formula or that, but without solid references spelling out its importance, we shouldn't be hyping it. In decades of being a physics person talking with other physics people, I haven't had one conversation that referred to it, very ''unlike'' the case for "Planck energy", and hunting through the literature strongly suggests that my sample is not too biased. [[User:XOR'easter|XOR'easter]] ([[User talk:XOR'easter|talk]]) 16:07, 21 May 2020 (UTC) |
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== Conversions between units? == |
== Conversions between units? == |
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Alternative choice of ℎ over ℏ
I think the section Alternative choices of normalization could/should include a section on using instead of .
Furthermore, this choice would be consistent with the use of other "rationalized" constants: instead of and instead of , since these constants are more related to the "full sphere" rather than a differential element of a (solid) angle. This is analogous to how relates to "cyclic" frequency whereas relates to angular frequency.
An example of related use would be the recent redefinition by the SI of the kg in terms of (and not ) and the former definition of the ampere related to (and not ). No examples of use of come to mind, though.
It would be nice to add a subsection with this, but currently I don't know of any sources using instead of .
—Cousteau (talk) 16:45, 19 October 2019 (UTC)
- I don't know for sure, but I think the motivation to normalize rather than is the same reason to normalize instead of . It's so that fewer scaling constants remain in the physical equations of interaction.2604:2000:D149:B000:A591:4CF3:93:372B (talk) 04:09, 29 October 2019 (UTC)
- It's the other way around; Coulomb's law is simpler if you use instead of , so is comparable to in this aspect. —Cousteau (talk) 12:55, 21 December 2019 (UTC)
No, normalize instead of , normalize instead of , normalize instead of , are more natural. Ahri6279 (talk) 13:48, 21 February 2020 (UTC)
Proposed split
The page Planck scale was once a separate article. Then, several years ago, it was proposed that it be merged here. No discussion took place so far as I can see, but it was redirected here, then edited to target Planck length. Recently the old article content was resurrected at Planck scale, which I reverted. To hopefully ward off any sort of edit war, I'm starting discussion here about whether any sort of content should be "split" from this article into an article about Planck scale, possibly that it should just be its own independent page without any content removed from here. Lithopsian (talk) 18:38, 26 November 2019 (UTC)
- I fail to see what's to be gained by extricating the scale aspect of this article to put in another article, to be left only with the unit aspects in this article, when both are so intimately linked. Headbomb {t · c · p · b} 10:15, 27 November 2019 (UTC)
- To clarify: all I have to go on is the edit summary "Distinct topic; relevant/public interest with recent science news". Perhaps @Vassyana: will further explain the need for a separate article. Or perhaps just let the issue die? Lithopsian (talk) 15:27, 27 November 2019 (UTC)
- I don't see any benefit to a separate article apart from the units since the scale is so closely related to the units. StarryGrandma (talk) 19:08, 30 November 2019 (UTC)
- Comment Plank units and Plank scale are basically the same concept, I suggest improving the content here rather than splitting. Polyamorph (talk) 06:45, 26 February 2020 (UTC)
"Planck units are free of anthropocentric arbitrariness. "
Is this remotely true?
For cvacuum, then yes, I accept that as a fundamental constant. However nearly all of the "Planck units" here are given with two values, depending on the choice of normalisation. Doesn't that mean that the whole notion of them being absolute has failed? Andy Dingley (talk) 01:10, 27 February 2020 (UTC)
- That's rounding, not anthropocentricness. Completely unrelated to one-another. Headbomb {t · c · p · b} 01:13, 27 February 2020 (UTC)
- How is this merely rounding? There's an (optional) factor of in there. Andy Dingley (talk) 00:54, 28 February 2020 (UTC)
- @Andy Dingley: I think I mixed up this talk page for another. I can't make any sense of my own comment here. Headbomb {t · c · p · b} 05:54, 31 March 2020 (UTC)
- How is this merely rounding? There's an (optional) factor of in there. Andy Dingley (talk) 00:54, 28 February 2020 (UTC)
- I think that the claim (that Planck units are free of anthropocentric arbitrariness) is overdone, and should be toned down or removed. There is an arbitrariness in the choice of factors as Andy Dingley points out, and the choice is rooted in our history, making it anthropocentric. The choice of constants to normalize is also anthropocentric: Why G and not Λ? Again a choice based on what we perceive as being more immediate. But perhaps we should hold off until the current editing spree by Ahri6279 has been cleaned up. —Quondum 14:01, 2 April 2020 (UTC)
- There are two versions of Planck units: Lorentz–Heaviside version (also called "rationalized") and Gaussian version (also called "non-rationalized"). Both of these two versions set , the Lorentz–Heaviside version sets , the Gaussian version sets . Ahri6279 (talk) 03:27, 3 April 2020 (UTC)
- @Quondum: “Why G and not Λ”? Planck units are not from any human construct (e.g. luminous intensity (cd), luminous flux (lm), and equivalent dose (Sv)) nor any quality of earth or universe (e.g. standard gravity, standard atmosphere, and Hubble constant) nor any quality of a given substance (e.g. melting point of water, density of water, and specific heat capacity of water). However, isn’t Λ (Cosmological constant) from a quality of universe? Ahri6279 (talk) 04:04, 3 April 2020 (UTC)
Recent expansion, lack of sourcing and many new redirects
See WP:Redirects for discussion/Log/2020 February 26#Planck angle Andy Dingley (talk) 01:12, 27 February 2020 (UTC)
- It has closed as delete. What else needs cleanup? I would support a pretty substantial rollback on this article and the deletion of all the recently-added derived units as unsourced. @Ahri6279: ? Andy Dingley (talk) 00:56, 5 March 2020 (UTC)
Why delete? I was curious and calculated almost all physical quantities in Planck (Lorentz–Heaviside or Gaussian) units, and I mainly collect the order of magnitude of the Planck units (e.g. Planck rotational inertia (Lorentz–Heaviside version) is about 10-61 kg.m2, and Planck electric induction (Lorentz–Heaviside version) is about 1061 V/m). —Ahri6279 (talk) 14:52, 5 March 2020 (UTC)
And before I added many physical quantities, there were already “Planck volumetric flow rate”, “Planck viscosity”, “Planck inductance“, and “Planck magnetic induction”, and I looked at them and think that this is not perfect, thus I added many physical quantities like “Planck rotational inertia”, “Planck capacitance”, “Planck electric induction”, and “Planck specific heat capacity”. —Ahri6279 (talk) 14:56, 5 March 2020 (UTC)
Same happening for me they delete me my derived Planck Units that I did an extension of one already exist it. @Ahri6279: I may sugestion you to save your data and move to wikiversity that allow new material, has I did so. Or do a home page with your material and then link it to source material on wikipedia, or seek on JTOR or links to keep it on this page. can you link wikiversity on here?. MarianGheorgheWiki (talk) 18:32, 21 March 2020 (UTC) 19:32, 21 March 2020 (UTC)
- How about you just source it, per WP:V and WP:RS ? Andy Dingley (talk) 18:41, 21 March 2020 (UTC)
- I would support a substantial rollback. This article has become a sea of noise: information irrelevant to the understanding of the topic, to the point that it drowns out the key points. And where does the idea of "Gaussian" and "Lorentz–Heaviside" versions of Planck units come from? I would like to see a notable source for that. —Quondum 18:17, 1 April 2020 (UTC)
- I too am concerned with the expansion. I would support a significant trimming down to units that have actually been used by scientists, and not just an arbitrary extension to all possible physical quantities. Headbomb {t · c · p · b} 19:44, 1 April 2020 (UTC)
- I also think that the article has become a sea of noise. The "Gaussian" and "Lorentz--Heaviside" versions of Planck units make the article unnecessary complicated. Much of recent stuff has to be removed.--Tjem Svasp (talk) 09:26, 5 April 2020 (UTC)
- I attempted a rollback and cleanup, but my work was reverted (with an edit that I can't help but feel indicates a complete lack of awareness of any of the policies and guidelines that make for encyclopedic writing). XOR'easter (talk) 15:08, 5 April 2020 (UTC)
- I would support a substantial rollback. This article has become a sea of noise: information irrelevant to the understanding of the topic, to the point that it drowns out the key points. And where does the idea of "Gaussian" and "Lorentz–Heaviside" versions of Planck units come from? I would like to see a notable source for that. —Quondum 18:17, 1 April 2020 (UTC)
- I understand your point of view. But I believe that being not the first to extend Planck units, I can ask you to make a separate page for only derivative Planck units. And leave only the most important here. the sources are there on google you will find tables full of derivative Planck units, some of them I made myself. I study physics, and I understand your copyright police and unreliable material. But I don't agree in doing it suppresses the creativity that the copiright denies. here it is theoretical quantum physics, not music or polita. I don't mean to say that anyone can afford to ruin Wikipedia pages now. but if there are experts in the field of those pages, but they have difficulty finding reliable sources, m, to which they can always make a contribution on the merit of the topic. I believe that user @Ahri6279: should definitely look for external sources or create an Homepage to use his work that source it. this presumptive material of Planck units has become very noisy in the fact that there are, many units, often also symbols that give us confusion. I would advise not to repress creativity but to give a hand to it to make sure that that material is not lost. Like making a Wikipeida page of unfit sources. out of 6/7 million articles on Wikipedia I don't think they are all within the law of the police and reliable sources. I believe that his material, @Ahri6279:, is very important for the research of gravitational physics. It is a crisis as today as Covid-19 and the imploding economy, and the deformation and deviation of the news. That does not allow the distinction between true and false. I think we shuold giva us more creativity with awareness of the arguments that the copyrights suppression by force as happens in Youtube or other platforms that does not allow Copyright. Wikipedia is as a last resort for not having this control with wisdom and respect for users to allow improvements and ideas. the page of Planck's units is only in the field of theoretical physics, so it is the only pure theory of those who have dedicated many years of research and publications. I think user @Ahri6279: should try type on Arxiv.com library to put his research. so he can cite his sources. with respect and health by those who have been studying Black Holes physics for over 13 years, but here in Italy these topics do not intresting much at all. I have economic and health problems that don't give me time to write a book or go to Arxiv.com for english language problems or the possibility of having visibility. obviously I do not want to offend anyone and your work is important and I respect this page of Planck units a lot but then I have to look elsewhere to have notions of quantum gravity. I apologize if I am emotionally involved but the work that user @Ahri6279: did was the same work I did it, even better in detail, with lacks of corrects symbols, but correct formulas. And I cried a lot, for days for losing everything on english Wikipedia. And seeing the same sufferings, like the user @Ahri6279:, seen repeated like me hurt so much. In a moment like this of a pandemic crisis that man has lost his sensitivity in the next one. To have control of the information that is always change in time and never static has the Copyrights it try to do so each time ( like the law of entropy in continuos change). so I ask you not to lose your brilliant work, the Gauss and Lorentz-Heavise units were already in natural units. Give him the opportunity to post that in-depth table on perhaps other platforms or other Wikipedia pages specific to these issues. with greetings and sincerity.MarianGheorgheWiki (talk) 13:45, 6 April 2020 (UTC)
- MarianGheorgheWiki, you clearly misunderstand the purpose of Wikipedia. It is expressly not a place for creativity or developing ideas. This is like choosing to play with your own construction ideas in the middle of a highway. There are other places where ideas can be worked on. Ahri6279 would have far more freedom to edit in his/her own sandbox on Wikipedia, where no-one would object. However, Ahri6279 persists in ignoring the objections of other editors and undoing what they do, and as a result risks being blocked from editing on Wikipedia. —Quondum 14:17, 6 April 2020 (UTC)
- Quondum I know! it's not a place of creativity. but since they also took my own stuff away from "talk page" or from senbox, last years. I was very bad and I fell into deppresion and I was very sick about this and I live with the anxiety of wikipedia. for user Ahri6279 need talk to us and understand his point of view do not restore old pages. and he will lose it all. You have to understand why he doesn't want to take away his material. there is a way to talk to him in sendbox or leave messages that I will talk to about how to find the sources and where his material moves.MarianGheorgheWiki (talk) 14:44, 6 April 2020 (UTC)
I'm in favour of removing all derived units. Planck angle? Planck volume? Planck absolute hardness? These and the rest are excessive. Attic Salt (talk) 15:30, 6 April 2020 (UTC)
- Yes, it's easy to invent Planck anything. Precious few of the quantities so invented have any use at all. Those are the ones we should be writing about. For example, "Planck area" is invoked in discussions of quantum gravity and black-hole entropy, where you'll see arguments like "there is one qubit associated to each Planck area of the event horizon". A Google Scholar search for "Planck area" turns up results in respectable journals by serious people: Baez, Bousso, Witten, etc. By contrast, searching for "Planck force" returns garbage in the Journal of Consciousness Exploration & Research and a few false positives (like a Physical Review paper that mentions a "Fokker–Planck force", which is something else entirely). I suspect that there's still more Planck-cruft in various pages that we haven't flushed out yet, added by people who think they can reveal the mysteries of creation by doing high-school algebra. XOR'easter (talk) 16:44, 6 April 2020 (UTC)
Multiple redirects listed at Redirects for discussion
An editor has asked for a discussion to address the redirect Planck electric displacement field. Please participate in the redirect discussion if you wish to do so. signed, Rosguill talk 17:40, 3 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck current density. Please participate in the redirect discussion if you wish to do so. signed, Rosguill talk 19:01, 5 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck specific activity. Please participate in the redirect discussion if you wish to do so. signed, Rosguill talk 19:46, 6 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck radiation exposure. Please participate in the redirect discussion if you wish to do so. signed, Rosguill talk 19:48, 6 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck catalytic activity. Please participate in the redirect discussion if you wish to do so. signed, Rosguill talk 19:52, 6 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck electric dipole moment. Please participate in the redirect discussion if you wish to do so. signed, Rosguill talk 19:54, 6 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck surface tension. Please participate in the redirect discussion if you wish to do so. signed, Rosguill talk 21:06, 7 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck wavenumber. Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 22:53, 7 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck specific volume. Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 22:54, 7 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck radiance. Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 20:33, 8 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck specific charge. Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 20:34, 8 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck thermal insulance. Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 22:24, 11 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck thermal transmittance. Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 23:38, 11 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck amount of substance. Please participate in the redirect discussion if you wish to do so. Utopes (talk / cont) 23:39, 11 April 2020 (UTC)
An editor has asked for a discussion to address the redirect Planck molar mass. Please participate in the redirect discussion if you wish to do so. signed, Rosguill talk 20:26, 15 April 2020 (UTC)
Named Planck units
It seems that it is easy to assume that "Planck *insert dimension name*" is automatically the name of a unit of the Planck unit system, and furthermore, that it is coherent with the others. Assumptions from SI unthinkingly find their way into the mix too. It is interesting to see how an internet search finds mostly the online echo chamber apparently created by the OR in this article. So I've thought to try to find notable use of names in this system, so that we can avoid inventing names in WP. The ones I've seen so far in reasonable secondary sources on the history and usage – I've not looked too hard yet – give notability to "Planck length", "Planck time", "Planck mass" and "Planck temperature", and I've seen sporadic mention of "Planck energy", "Planck density" (but not enough to qualify these as an established part of the system). I don't put much weight on individual papers: they invent variations of the system and terms to suit the purpose of the paper. One notable absence is "Planck charge", which was not in the system as proposed by Planck. —Quondum 00:45, 10 May 2020 (UTC)
- "Planck energy" is definitely a term people actually say; I'm much more dubious on "Planck density". XOR'easter (talk) 16:38, 10 May 2020 (UTC)
- Following on from this, every source that I can remember that has spoken historically about the Planck unit system has made it fairly clear that the electromagnetic dimension is not part of the system, either as Planck defined it originally or its modern variant with the reduced Planck constant. Currently, what is in the article amounts to what can be found in some primary sources as a definition for convenience, which it seems to me should not be reported here. Consequently, I think the Planck charge should be removed as "a Planck unit" and its inclusion limited to a mention of its status in this regard. Should anyone have references that contradict this perspective, these would be welcome. —Quondum 14:25, 21 May 2020 (UTC)
- The Planck charge is very important and it is a base (non-derived) unit. It is actually a very peculiar unit, since it is the only Planck unit that does not depend on the gravitational constant, so its value is known with high precision (and before the last changes in SI it was the only Planck unit whose value was exact by definition). It establishes a relationship between electric and gravitational force: take two flea eggs, charge them with of positive charge each (i.e., a Planck charge, value known nearly exactly – as for the fact that the value is not an integer number of elementary charges, it is very easy to find the right workaround), if they don't repel each other because their gravitational force balances exactly their electric repulsion you have got two Planck masses – and you have got them without having to know the exact value of G. Furthermore the Planck charge appears as a limit in the Reissner–Nordström metric for a charged Planck black hole. The original Planck units were different than the ones used today – I have posted a table in the article: if you feel like removing the Planck charge just because it was not present in the original proposal written by Planck you should also multiply all other units by (but then this article will finally be completely useless). --Grufo (talk) 15:36, 21 May 2020 (UTC)
- It shows up in this formula or that, but without solid references spelling out its importance, we shouldn't be hyping it. In decades of being a physics person talking with other physics people, I haven't had one conversation that referred to it, very unlike the case for "Planck energy", and hunting through the literature strongly suggests that my sample is not too biased. XOR'easter (talk) 16:07, 21 May 2020 (UTC)
- The Planck charge is very important and it is a base (non-derived) unit. It is actually a very peculiar unit, since it is the only Planck unit that does not depend on the gravitational constant, so its value is known with high precision (and before the last changes in SI it was the only Planck unit whose value was exact by definition). It establishes a relationship between electric and gravitational force: take two flea eggs, charge them with of positive charge each (i.e., a Planck charge, value known nearly exactly – as for the fact that the value is not an integer number of elementary charges, it is very easy to find the right workaround), if they don't repel each other because their gravitational force balances exactly their electric repulsion you have got two Planck masses – and you have got them without having to know the exact value of G. Furthermore the Planck charge appears as a limit in the Reissner–Nordström metric for a charged Planck black hole. The original Planck units were different than the ones used today – I have posted a table in the article: if you feel like removing the Planck charge just because it was not present in the original proposal written by Planck you should also multiply all other units by (but then this article will finally be completely useless). --Grufo (talk) 15:36, 21 May 2020 (UTC)
- Following on from this, every source that I can remember that has spoken historically about the Planck unit system has made it fairly clear that the electromagnetic dimension is not part of the system, either as Planck defined it originally or its modern variant with the reduced Planck constant. Currently, what is in the article amounts to what can be found in some primary sources as a definition for convenience, which it seems to me should not be reported here. Consequently, I think the Planck charge should be removed as "a Planck unit" and its inclusion limited to a mention of its status in this regard. Should anyone have references that contradict this perspective, these would be welcome. —Quondum 14:25, 21 May 2020 (UTC)
Conversions between units?
Grufo, could you motivate the inclusion of Planck units#Conversions? —Quondum 11:42, 13 May 2020 (UTC)
- @Quondum: I think that an encyclopedia is a great place for tables, and in particular that conversion table shows visually what any set of units of measurement must satisfy (plus, it comes very much in handy if you are a physicist). --Grufo (talk) 21:49, 13 May 2020 (UTC)
- I disagree that an encyclopaedia is a great place for tables. It is a great place for useful information, and tables sometimes can convey useful information compactly. Conversion between (or interchanging) incommensurate units is not something anyone needs to do. I have my doubts about whether this will be handy to anyone who understands what they are doing – I can't even figure out what you mean by "what any set of units of measurement must satisfy". Imagine a similar table for converting between seconds, kilograms, etc., in the SI article! If you can't find it published in a reputable source, it doesn't belong here. —Quondum 22:52, 13 May 2020 (UTC)
- @Quondum: They are not incommensurate units when you balance them with dimensional constants. In our current understanding of physics, with any set of units of measurement used, by knowing the speed of light in vacuum, the gravitational constant, the reduced Planck constant, the Boltzmann constant and the Coulomb constant it is always possible to switch from a dimension to another (i.e., apparently unrelated dimensions are inter-dependent). And the whole point of Planck units is to be the privileged points where these conversions happen (whatever system you use to measure them). Albert Einstein's mass–energy equivalence and Erik Verlinde's entropic gravity are the first examples that come to my mind of "conversion between incommensurate units". --Grufo (talk) 23:10, 13 May 2020 (UTC)
- I disagree that an encyclopaedia is a great place for tables. It is a great place for useful information, and tables sometimes can convey useful information compactly. Conversion between (or interchanging) incommensurate units is not something anyone needs to do. I have my doubts about whether this will be handy to anyone who understands what they are doing – I can't even figure out what you mean by "what any set of units of measurement must satisfy". Imagine a similar table for converting between seconds, kilograms, etc., in the SI article! If you can't find it published in a reputable source, it doesn't belong here. —Quondum 22:52, 13 May 2020 (UTC)
- The very definition of Planck units makes this a trivial table of the ratios of the Planck units that the reader who has read up to that point should be able to write down for him/herself. So, if something should be said about such conversions, then one could mention that one can take such ratios. For example, what might be useful to mention is how after having set hbar = G = c = 1 and everything has been made dimensionless and a formula X = f(Y1, Y2,...,Yn) has been found, how does one get back to conventional units? The answer is then X/Xp = f(Y1/Y1p, Y2/Y2p,...,Yn/Ynp) where Xp and the Yjp are the Planck unit quantities for the variables. This doesn't change anything because the Planck unit quantities are equal to 1 in the dimensionless hbar = G = c = 1 units. But the formal equation with these Planck unit quantities included is now dimensionally correct in a conventional unit system. Count Iblis (talk) 17:05, 15 May 2020 (UTC)
The very definition of Planck units makes this a trivial table of the ratios of the Planck units that the reader who has read up to that point should be able to write down for him/herself.
Yes. There is also a bit of a due weight concern; it's always possible that somebody will want to write a time in terms of the Planck temperature, or a temperature in terms of the Planck charge, but I'll bet that doesn't happen too often. Nor, per WP:NOTTEXTBOOK, are we in the business of stepping through routine interconversions. XOR'easter (talk) 04:42, 17 May 2020 (UTC)- Since everybody but Grufo think the article shouldn't have the conversion table I removed it. Tercer (talk) 18:04, 17 May 2020 (UTC)
- Sorry guys, I hadn't realized this discussion was continuing…
- @Count Iblis: “the reader who has read up to that point should be able to write down for him/herself” Those equations are all very easy to find. But they are twenty… This is exactly the kind of situation where you would like to have a table rather than finding each of them on your own.
- @XOR'easter: “it's always possible that somebody will want to write a time in terms of the Planck temperature, or a temperature in terms of the Planck charge, but I'll bet that doesn't happen too often” About how useful an information is I cannot speak for the entire world and I am sure many will agree with you.
- I would propose to restore the table as collapsible, but only if some consensus is reached. --Grufo (talk) 01:21, 19 May 2020 (UTC)
- Since everybody but Grufo think the article shouldn't have the conversion table I removed it. Tercer (talk) 18:04, 17 May 2020 (UTC)
- The very definition of Planck units makes this a trivial table of the ratios of the Planck units that the reader who has read up to that point should be able to write down for him/herself. So, if something should be said about such conversions, then one could mention that one can take such ratios. For example, what might be useful to mention is how after having set hbar = G = c = 1 and everything has been made dimensionless and a formula X = f(Y1, Y2,...,Yn) has been found, how does one get back to conventional units? The answer is then X/Xp = f(Y1/Y1p, Y2/Y2p,...,Yn/Ynp) where Xp and the Yjp are the Planck unit quantities for the variables. This doesn't change anything because the Planck unit quantities are equal to 1 in the dimensionless hbar = G = c = 1 units. But the formal equation with these Planck unit quantities included is now dimensionally correct in a conventional unit system. Count Iblis (talk) 17:05, 15 May 2020 (UTC)
I paste the table here. My proposal is to restore the paragraph in this form:
(paragraph to be restored under § Definition) | ||||||||||||||||||||||||||||||||||||
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ConversionsThe following table shows the mutual interchangeability of Planck base units.
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--Grufo (talk) 14:23, 21 May 2020 (UTC)
Individual articles
Wikipedia used to have a separate page for most Planck units, and in many cases they were good articles. However recently all of them have been removed and they all redirect here now. I would like to restore them. --Grufo (talk) 20:34, 14 May 2020 (UTC)
- Which were the good ones? I think I looked at all of them, and I can't recall any that stood out as worth being stand-alone articles. It's all one topic. XOR'easter (talk) 21:21, 14 May 2020 (UTC)
- Onestly all of them contain either a paragraph about their significance or interesting related facts (which you cannot merge into a gigantic single article – well, you could… but you wouldn't do a good service to an encyclopedia).
- Base units (latest revisions):
- Derived units (latest revisions):
- These were the last revisions of the pages before they have been removed. Some articles never existed (Planck frequency for example), but I could start working on them. --Grufo (talk) 00:11, 15 May 2020 (UTC)
- You really don't listen to others, do you? Others object to what you do or say (above being an example), and you refuse to acknowledge what they have said. This is not the way to get cooperation from others. If you go ahead against consensus, such articles will almost certainly not survive an Article for Deletion discussion. Save yourself the trouble. —Quondum 00:37, 15 May 2020 (UTC)
- @Quondum:
- “You really don't listen to others, do you?” Uhm?
- “Others object to what you do or say (above being an example), and you refuse to acknowledge what they have said.” Seriously? I feel some personal issue here. Do I have to assume that XOR'easter's question “Which were the good ones” was a rhetorical question or do you think it deserved an answer? If it did deserve an answer, as I think, I gave the most sincere answer I could think of. Now, since I don't like being rhetorical, please, you do answer this question: What exactly did I not listen to?
- --Grufo (talk) 01:01, 15 May 2020 (UTC)
- My question was not rhetorical, but revisiting the articles now, I find that my assessment has not changed. A few scattered "interesting facts" do not an article make, and the subject becomes harder to understand when doled out piecemeal rather than being explained as, well, a system of units. Moreover, the density of fringey cruft and marginal speculation was unhelpfully high. XOR'easter (talk) 03:52, 15 May 2020 (UTC)
- @Quondum: There are five main reasons why I think the individual articles should be restored:
- 1. Planck units are not like any other unit and per se deserve separate articles. This gives the possibility to report important information specific to each topic.
- 2. As the articles were, in my opinion there was information that deserved to be saved together with information that needed to be improved. Sure, there was also fringey cruft, but reacting to that by removing entire pages instead of fixing the fringey cruft does not seem very constructive to me.
- 3. Separate articles help reducing the size of the Planck units article.
- 4. The task of the individual articles must not necessarily be that of adding further information. They could serve a good cause also by simply explaining the same things explained in the Planck units article more clearly and with the necessary number of words.
- 5. Future improvements: individual articles give more rooms to users for improving the content when compared to a gigantic single page that must be kept constantly under a certain number of words
- “Which were the good ones?” My fast selection of relatively good material:
If an object were to reach the temperature of 1.42×1032 kelvin (TP), the radiation it would emit would have a wavelength of 1.616×10−35 m (Planck length), at which point quantum gravitational effects become relevant.
Or, to put it in different words, the energy required to accumulate one Planck charge on a sphere one Planck length in diameter will make the sphere one Planck mass heavier:
Unlike most of the other Planck units, Planck momentum occurs on a human scale. By comparison, running with a five-pound object (108×Planck mass) at an average running speed (10−8×speed of light in a vacuum) would give the object Planck momentum. A 70 kg human moving at an average walking speed of 1.4 m/s (5.0 km/h; 3.1 mph) would have a momentum of about 15 . A baseball, which has mass 0.145 kg, travelling at 45 m/s (160 km/h; 100 mph) would have a Planck momentum.
The ultra-high-energy cosmic ray observed in 1991 had a measured energy of about 50 joules, equivalent to about 2.5×10−8 EP.[1] Theoretically, the highest energy photon carries about 1 EP of energy (see Ultra-high-energy gamma ray). Most Planck units are extremely small, as in the case of Planck length or Planck time, or extremely large, as in the case of Planck temperature or Planck acceleration. For comparison, the Planck energy is approximately equal to the energy stored in an automobile gas tank (57.2 L of gasoline at 34.2 MJ/L of chemical energy).
Since 1993, various authors (De Sabbata & Sivaram, Massa, Kostro & Lange, Gibbons, Schiller) have argued that the Planck force is the maximum force value that can be observed in nature. This limit property is valid both for gravitational force and for any other type of force.
This is a unit which is very large, about equivalent to 1023 solar masses squeezed into the space of a single atomic nucleus.
The Planck density is thought to be the upper limit of density- The Old revision of Planck acceleration contains also both fringey cruft and acceptable article material.
- But again the question simply is: Do Planck units deserve a separate article in an encyclopedia? If the answer is yes we should:
- 1. Restore all the articles removed
- 2. Fix and improve them
- Now, considering that most non-English Wikipedia have separate articles for the Planck units, considering that even Wiktionary has an article for Planck frequency and considering the current size of the Planck units page, I do think that all Planck units deserve a separate article. --Grufo (talk) 04:42, 15 May 2020 (UTC)
- Wikipedias in different languages have different inclusion standards, and what works for one does not necessarily translate to another. The existence of a dictionary definition does not mean that an encyclopedia article is warranted; after all, Wikipedia is not a dictionary. Meanwhile, this article only looks long because it has a few tables and because nobody has deleted the "invariant scaling of nature" section and its OR-ish, fringey waffling yet. XOR'easter (talk) 14:06, 15 May 2020 (UTC)
- My question was not rhetorical, but revisiting the articles now, I find that my assessment has not changed. A few scattered "interesting facts" do not an article make, and the subject becomes harder to understand when doled out piecemeal rather than being explained as, well, a system of units. Moreover, the density of fringey cruft and marginal speculation was unhelpfully high. XOR'easter (talk) 03:52, 15 May 2020 (UTC)
- @Quondum:
- You really don't listen to others, do you? Others object to what you do or say (above being an example), and you refuse to acknowledge what they have said. This is not the way to get cooperation from others. If you go ahead against consensus, such articles will almost certainly not survive an Article for Deletion discussion. Save yourself the trouble. —Quondum 00:37, 15 May 2020 (UTC)
Notes
- ^ "HiRes - The High Resolution Fly's Eye Ultra High Energy Cosmic Ray Observatory". www.cosmic-ray.org. Retrieved 2016-12-21.