Wikipedia talk:WikiProject Physics

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Request to merge "megasonic cleaning" into "ultrasonic cleaning"?

I recently joined Wikipedia and my first suggested edit was to Megasonic cleaning. My guess is that this article would belong better as a subsection of the article on Ultrasonic cleaning. The help article Help:Introduction_to_talk_pages/All suggested that I draw some attention to it, since the article is a bit obscure.

Physics Essays

There have been intermittent efforts to make the publication Physics Essays look more respectable than it is. Watchlisting seems advisable. XOR'easter (talk) 18:45, 23 August 2024 (UTC)

Example at Talk:Alternatives to general relativity#Newer MOND theories? - DVdm (talk) 20:53, 26 August 2024 (UTC)

No I don't think this is related. One of the two papers is in Phys Rev Letters which has good peer review though it deliberately allows new material, eg the famous magnetic monopole. The other paper is Phys Rev D, quite staid. These are just more entries in the gravity lottery. Johnjbarton (talk) 22:30, 26 August 2024 (UTC)

Nomination of List of important publications in geology for deletion

A discussion is taking place as to whether the article List of important publications in geology is suitable for inclusion in Wikipedia according to Wikipedia's policies and guidelines or whether it should be deleted.

The article will be discussed at Wikipedia:Articles for deletion/List of important publications in geology (3rd nomination) until a consensus is reached, and anyone, including you, is welcome to contribute to the discussion. The nomination will explain the policies and guidelines which are of concern. The discussion focuses on high-quality evidence and our policies and guidelines.

Users may edit the article during the discussion, including to improve the article to address concerns raised in the discussion. However, do not remove the article-for-deletion notice from the top of the article until the discussion has finished.

Kevmin § 22:35, 25 August 2024 (UTC)

Comments requested on Thermal energy

There is an odd article Thermal energy which, to me, seems to be a bad conflation of "true thermal" (phonons), enthalpy (probably wrt STP, but that is not defined), internal energy (also undefined in the article) and the thermodynamic state variable (with k_b). It also has too many unsourced statements, and I think some WP:SYNTH and WP:OR (or at the least not NPOV). I amrequesting comments before doing anything else, this is a high importance physics page, although it was not categorized under physics. Maybe start here, or go to that talk page. Ldm1954 (talk) 22:47, 25 August 2024 (UTC)

I avoid editing the article Thermal energy because I think it is too heavily loaded with opinion.Chjoaygame (talk) 00:31, 26 August 2024 (UTC)

Redirect to Kinetic energy. Johnjbarton (talk) 01:00, 26 August 2024 (UTC)

Kinetic energy does not discuss thermal effects, so a redirecting there would not useful. Also, the energy associated with thermal motion corresponds to kinetic energy only for simple gases.

Not sure what to do with the article though, except that I think it should be more concise. We should perhaps consider the incoming links to see what kind of article is needed. There are at least three different kinds of incoming links:

• In some cases, e.g. thermal energy storage, the meaning is associated with internal energy.
• In others, it refers to statistical distribution of constituent particle energies which is affected by temperature.
• There is perhaps also some meaning associated with thermal transport or generation of heat

Jähmefyysikko (talk) 07:03, 27 August 2024 (UTC)

Without a reliable reference that discusses specifically "thermal energy" as a type of energy we'll never succeed at an article that can pass verification. In my opinion the current article would not be accepted if offered as a create: the notability of the title is not established in the text. Logically then we should not have the article unless some can address this fundamental issue.

One random source implicitly defines thermal energy as energy proportional to $\Delta T$.

• A. Cuadras, M. Gasulla, V. Ferrari, Thermal energy harvesting through pyroelectricity, Sensors and Actuators A: Physical, Volume 158, Issue 1, 2010, https://doi.org/10.1016/j.sna.2009.12.018.

That makes sense to me, but this is not sufficient. Something like "thermal energy" needs to be sourced to a text book. The first reference in Heat is for this lead:

• In thermodynamics, heat is the thermal energy transferred between systems due to a temperature difference.

I don't have access to the ref, but if someone does we have a solution. Johnjbarton (talk) 15:16, 27 August 2024 (UTC)

I have part done a survey of many many textbooks, mainly thermodynamics, that devote attention to heat as a major topic; I confess that there are yet more textbooks that should be included in my survey. There are two main approaches. One is that of the now obsolete caloric theory of heat, that heat is characterised in terms of temperature; this approach appeals mostly to engineers who are considering heat transport, and currently rules the lead of the article on Heat. The other is the classical thermodynamic approach that defines heat as energy in transfer by mechanisms other than thermodynamic work or transfer of matter. For some decade or so, Wikipedia's thoroughly debated editorial consensus preferred the latter. At present, I do not have the strength to try to restore it. The reason for the thermodynamic approach is partly that, in thermodynamics, absolute temperature is not defined until the second law has been stated, and that it is desirable to define heat solely in terms of the first law before stating the second law. Nowadays, the SI definition of temperature is not that of classical thermodynamics; nowadays, the SI definition of temperature is classified in thermodynamics as an empirical temperature, as distinct from the absolute thermodynamic concept. The classical thermodynamic approach has the advantage that it makes it a matter of pure logic that for a closed system, energy transfer is by either thermodynamic work or heat. It may be worth remarking that mechanical work is distinct from thermodynamic work, and that energy transfer with matter cannot be uniquely resolved into work and heat. It is also relevant that Planck (1927) gives emphasis to the production of heat by friction as an irreversible process.Chjoaygame (talk) 23:29, 27 August 2024 (UTC)

I am glad to observe that ISO 80000 distinguishes between its definition of thermodynamic temperature and its prescriptions for temperature measurements. Thermodynamics regards the latter as empirical temperatures. The definition of entropy rests on the concepts of heat and of thermodynamic work. Am I reading it aright, that ISO 80000 does not distinguish between mechanical work and thermodynamic work? Mechanical work is defined by mechanical quantities in the surrounds of the thermodynamic system. Thermodynamic work is defined by measurable state variables of the thermodynamic system.Chjoaygame (talk) 05:59, 28 August 2024 (UTC)

The source says: Heat is defined as the form of energy that is transferred across the boundary of a system at a given temperature to another system (or the surroundings) at a lower temperature by virtue of the temperature difference between the two systems. The book only contains the phrase "thermal energy" much later on page 509, where they discuss the third law, and there is a sentence Further, since the temperature is absolute zero, the thermal energy is minimum. However, "thermal energy" is not defined.

One textbook that uses the phrase heavily is Blundell & Blundell, Concepts in Thermal Physics. The book contains passages such as Heat is thermal energy in transit and ...a deficit of thermal energy given by C dT..., but they never define "thermal energy" explicitly. I think this is quite common in thermodynamics textbooks. Thermal energy is such a natural sounding concept, but no function of state quite corresponds to it on closer analysis. Jähmefyysikko (talk) 16:31, 27 August 2024 (UTC)

Here's a statement we can source ;)

The concept of thermal energy is by all odds the most obscure, the most mysterious, and the most ambiguous term employed by writers of elementary physics and by chemists. Zemansky in 'Use and misuse of the word "heat" in physics teaching' (1970) Jähmefyysikko (talk) 16:47, 27 August 2024 (UTC)

Great, I think that is the basis for reworking the article to reflect what you have uncovered so far. Don't try to give a definition, but just point to issues and examples as you have done here. To me that reflects the sources much more than what is there now. Johnjbarton (talk) 22:12, 27 August 2024 (UTC)

I more or less agree with Zemansky on this point.Chjoaygame (talk) 23:32, 27 August 2024 (UTC)

It'd be nice to clear heat of references to thermal energy. The ISO 80000 definition is authoritative: [1] fgnievinski (talk) 03:21, 28 August 2024 (UTC)

I think the Wikipedia policy of referring to established textbooks, regarded as reliable sources, is a good one.Chjoaygame (talk) 05:43, 28 August 2024 (UTC)

What is spin-1/2 Heisenberg XXZ?

Hi. I am not an expert in physics, so I ask here. We have an article about Spin chain, especially about Spin-1/2 Heisenberg XXX. Some sources mention about XXZ, as in this arXiv [2]. So my question is what is that thing? What are the differences between those two? Regards. Dedhert.Jr (talk) 06:00, 27 August 2024 (UTC)

Its about symmetry. In the above arXiv paper, consider the XXZ Hamiltonian given in Eq. (2.1). The X and Y spins have the same prefactor Δ, while Z is different. For XXX all spins have the same prefactor in the Hamiltonian. Jähmefyysikko (talk) 06:18, 27 August 2024 (UTC)

Oh. I see. Dedhert.Jr (talk) 06:21, 27 August 2024 (UTC)

@Jähmefyysikko I have added this in one of polyhedral articles: triangular cupola. This is somewhat short, probably because of less background. Would you like to assist me in this case, as the technical part would like to be explicitly explained for non-science audience? Dedhert.Jr (talk) 06:39, 27 August 2024 (UTC)

Hi, sorry but I don't think we should add this to the cupola article unless there is some very special property that only occurs there. The games theoretical physicist play with various geometries is not something we need to cover in an encyclopedia. Jähmefyysikko (talk) 07:08, 27 August 2024 (UTC)

Collapse of wavefunction in Stern-Gerlach experiment: observational verification

It has been shown that the atomic wavefunction traversing the Stern-Gerlach magnet immediately collapses to one spin eigenfunction when a field quantum is absorbed by the atom. (See the "Importance" section of the S-G page.) This contradicts almost a hundred years of mistaken explanation in our textbooks and research papers.

I've discovered that a remarkably simple, and practical experiment can now corroborate that understanding (Published in the J. of Physics B very recently (Devereux, 2024, https://doi.org/10.1088/1361-6455/ad5992). There is much resistance to such a new understanding, and its confirmatory observation, from researchers who have uncritically accepted the received explanation. I'm asking for acceptance from the community here that I be allowed to edit the "Importance" section of the S-G page to include a citation to that recent J. Phys. B article. The J. Phys. B publication lacks some of the criteria for an immediate reedit to Wikipedia: just one author, and no citations to that article yet. Still, I would like to make that edit now because of the critical importance to quantum measurement and Q.M. foundations of realistically describing the S-G experiment. D bar x (talk) 21:45, 28 August 2024 (UTC)

If the result is as fine as you say it is it will soon received hundreds of citations in the scientific literature. That will determine if it is notable enough for Wikipedia. As far as I can see the paper has received zero citations so far. Wikipedia follows but does not lead. Xxanthippe (talk) 00:58, 29 August 2024 (UTC).

Just for visibility, my explanation for reverting the edit is on the Quantum superposition Talk page. Johnjbarton (talk) 04:31, 29 August 2024 (UTC)

Talk:Mean radius

Could I have extra eyes at Mean radius/Talk:Mean radius. There's a dispute about whether or not certain things are mean/effective diameters/radii, and providing sources (or common sense) doesn't seem to help. Headbomb {t · c · p · b} 00:53, 29 August 2024 (UTC)

Proposed merge of Evolution equations in high-energy particle physics into Pomeron

Please weigh in at Talk:Pomeron#Proposed_merge_of_Evolution_equations_in_high-energy_particle_physics_into_Pomeron.

Instead the orphan article Evolution equations in high-energy particle physics could be deleted. At least it must be renamed. Johnjbarton (talk) 23:52, 4 September 2024 (UTC)

Featured article review of Heavy metal (elements)

I have started a Featured article review of Heavy metal (elements), please follow the link to the source. Based upon reading the sources too many did not validate; Johnjbarton also had some serious criticisms. Ldm1954 (talk) 23:29, 6 September 2024 (UTC)

N.B., the main page entry is Wikipedia:Featured article review#Heavy metal (elements), the link above is a page for just this FAR. Ldm1954 (talk) 00:19, 7 September 2024 (UTC)

Isoelectric (electric potential) nominated for deletion

The page Isoelectric (electric potential) is pretty awful, and was just nominated for deletion. Obviously the topic is important. It either should be expanded in its own right, or because redirect to a relevant section in an existing page. Anyone know a good place for a redirect, or failing that improve it? Ldm1954 (talk) 19:46, 7 September 2024 (UTC)

First successful attempt to connect relativity and quantum mechanics?

• Srichan, Chavis; Danvirutai, Pobporn; Cheok, Adrian David; Cai, Jun; Yan, Ying (2025). "On the same origin of quantum physics and general relativity from Riemannian geometry and Planck scale formalism". Astroparticle Physics. 164. doi:10.1016/j.astropartphys.2024.103036.

I won't lie, this paper is beyond my level, but it makes rather (if true), truly phenomenal claims, purporting to explain/give a framework from everything from the Dirac equation, Einstein field equations, Maxwell's equations, quantum field theory, chromodynamics, particle masses, predicts a ν_τ > ν_e > ν_μ hierarchy, black hole dynamics, EPR paradox and more.

It's making a splash in popular media (in that it popped in my Google news feed anyway), but I've yet to see a critical look at it.

One thing that's puzzling to me is the background of the scientists involved. Engineers working in nanomaterials and atmospheric scientists, as far as I can tell. Headbomb {t · c · p · b} 06:01, 8 September 2024 (UTC)

Extraordinary claims require extraordinary evidence. I suggest wait for the citations to roll in WP:NOTTHENEWS. Xxanthippe (talk) 06:15, 8 September 2024 (UTC).

Digging deeper in the paper, there are bits I just find ludicrous like connecting particle mass to the radius of the solar system, so I doubt this will pan out. Headbomb {t · c · p · b} 06:28, 8 September 2024 (UTC)

I note a bizarre invocation of Onsager's principle of irreversible thermodynamics. My guess is that the paper is garbage. I do hope that I am wrong. Xxanthippe (talk) 06:44, 8 September 2024 (UTC).

One issue I will raise: notability. I think this paper is notable, but it is too soon to create an article. Notability will be because:

1. It is right.
2. Someone got it past Elsevier editors.

I checked the nanochopsticks fake, and I did not find an article on it. Should we have articles on notable fakes -- we do have fringe science? (Most people teaching electron microscopy use it as an example of what not to do; it was astonishing that it got past reviewers.) Ldm1954 (talk) 08:13, 8 September 2024 (UTC)

I've taken a look at the paper. It's nonsense. Complete and utter drivel. It's so absurd that I don't think even the authors can possibly believe in it. I tried to follow the equations, it's a series of non-sequiturs. Maybe we are dealing with a Sokal affair? Elsevier has a terrible reputation, but I wouldn't expect even them to publish such a thing. Only purely predatory journals should do it; Astroparticle Physics (journal) seems instead a run-off-the mill low-impact journal.

Notability might come from news reporting, until then we should ignore this. Tercer (talk) 09:28, 8 September 2024 (UTC)

Even with news reporting, it should probably be ignored, because news reporting will be rather run of the mill "so and so claims to have done x". Unless it's getting proper citations (rather unlikely), or just gets properly savaged/debunked, this is a nothing burger. I can't judge the parts with Ricci stuff and Riemannian whatevers, but the other claims are so ludicrous e.g. "Because a quark is equivalent to a confined electron in the fractal dimension of space–time, it results in a larger interaction energy... The mass of the down quark, m_d should be proportional to (3e)² because we divide the electron into 1/3 fractal dimensions. Hence, ..." Headbomb {t · c · p · b} 11:22, 8 September 2024 (UTC)

Someone got it past Elsevier editors. And that plus three bucks will buy you a cup of coffee [3]. XOR'easter (talk) 18:06, 11 September 2024 (UTC)

I had a quick look. These authors are confused about a large number of things. Relating the scale of the solar system to particle masses is fantasy, spacetime is not generally a Lie group on which the covariant derivative acts as a Lie derivative, the Ricci tensor is not generally equal to the the Einstein tensor, etc. They do show more facility with equations than most crackpots, but less than some. I would expect this paper to be aggressively ignored, other than being yet another black eye for Elsevier and conventional peer review. Dilaton (talk) 12:53, 9 September 2024 (UTC)

Can any encyclopedia-article title here, start with these exact words?

['Title here'] "is an electric field responsible for the solar wind in the upper atmosphere, about 150 miles (240 km) above the surface of the earth. The field is one of three known energy fields around the planet Earth. The other two are gravity and the magnetic field. It causes the polar winds which are experienced by pilots at the poles of Earth".

Does established knowledge, clearly indicate the above? Is it likely that the 'quoted' text, is ready to go, as the start of a Wikipedia-article? Thanks! 2001:2020:355:B15E:A943:FB21:996A:3DDC (talk) 18:34, 11 September 2024 (UTC)

The lead section of an article is a summary. The article itself must have content supported by verifiable sources. Without that content and sources there is no way to answer your question. Johnjbarton (talk) 18:41, 11 September 2024 (UTC)

The background for my question, is that En-wiki seems not to illuminate much of what the following link is (seemingly) trying to get at.

(Link, to what i 'quoted':

simple.wikipedia.org/wiki/Ambipolar_electric_field
).

I already have my answer, i guess.--Thank you for user:Johnjbarton, having replied. 2001:2020:355:B15E:FD06:7DB1:FA2B:16EA (talk) 19:37, 11 September 2024 (UTC) /2001:2020:355:B15E:A943:FB21:996A:3DDC

The page in question seems to be Earth's ambipolar electric field, and I wonder if others on this page have any thoughts about notability? PianoDan (talk) 19:40, 11 September 2024 (UTC)

August 28 - "Nature" published an article.--NASA seems to have commented (?) that article on the same day.--The article on En-wiki was published on September 2.--Notable claim, it might seem. But from there ... (sources of error, calibration of equipment)? 2001:2020:355:B15E:FD06:7DB1:FA2B:16EA (talk) 20:34, 11 September 2024 (UTC)

From what I can see people thought it existed, but it had not (until now) been measured. Given that the concept is apparently well established, it seems to be appropriate for Wikipedia. Ldm1954 (talk) 21:30, 11 September 2024 (UTC)

Absent a consensus to create an exception, the article as written should be deleted. It relies on two sources which are too new to be used. There does seem to be other sources so the article could be written based on those sources. Given other reliable sources, the exception for the new primary reference might be reasonable as it is peer reviewed, in a top journal, and based on a team effort. Johnjbarton (talk) 23:02, 11 September 2024 (UTC)

The wiki-article's title, does not seem like established science. If that is the case, then there might be consensus to change the title (even if the article might get nominated for Deletion, at any time, down the road.)

Dude/dudette Smith et al (year 1960) 'theory about Earth's electrical field'?
Electrical-field measured in ionosphere?
Voltage-drop (observation) in ionosphere.

Is there a better title ('for what such an article should be about')? Thoughts? 2001:2020:355:B15E:BD3D:61C:8074:C82F (talk) 01:13, 12 September 2024 (UTC) /2001:2020:355:B15E:A943:FB21:996A:3DDC

Moving the article, into 'its own' section in say, the Ionosphere, or the Polar wind (wiki-article)? Should that be ruled out? 2001:2020:355:B15E:4920:891D:B9FA:B0A9 (talk) 01:29, 12 September 2024 (UTC) /2001:2020:355:B15E:A943:FB21:996A:3DDC /2001:2020:355:B15E:4920:891D:B9FA:B0A9 (talk) 01:50, 12 September 2024 (UTC)

"It causes the polar winds which are experienced by pilots at the poles of Earth" is just wrong. Fix that in simple, do a merge here of Earth's ambipolar electric field into Polar wind. Dicklyon (talk) 02:07, 12 September 2024 (UTC)

Such a merge (into "Polar wind"), might start with (my phrase, if no one else has used it yet),
"Ambipolar electric field in the ionosphere".--That field being 'indicated' might be too big words; perhaps one should say that the measurements are suggested to indicate the existence of (an) ambipolar electric field in the ionosphere (or indicate the existence of that field in at least a patch/'sector' of that atmospheric layer).--Thanks to user:Dicklyon. 46.15.15.157 (talk) 18:39, 12 September 2024 (UTC) /2001:2020:355:B15E:A943:FB21:996A:3DDC /2001:2020:307:9EF5:F44B:289:5E97:735D (talk) 18:41, 12 September 2024 (UTC)

"Polarization electric field in the ionosphere" (or 'in a patch thereof'). 2001:2020:31B:D1A2:DD2C:839B:26E8:9AF1 (talk) 01:41, 14 September 2024 (UTC) /2001:2020:355:B15E:A943:FB21:996A:3DDC

I think this discussion, can be moved to talk page of, say, Polar wind.--Justification? This diff,
en.wikipedia.org/w/index.php?title=Earth%27s_ambipolar_electric_field&diff=1245614451&oldid=1245389185
, might be a justification-in-part. 2001:2020:31B:D1A2:DD2C:839B:26E8:9AF1 (talk) 02:26, 14 September 2024 (UTC) /2001:2020:355:B15E:A943:FB21:996A:3DDC

Spaghettification and pancaking

Some input might be needed at Talk:Spaghettification#Pancaking regarding a recent string of (i.m.o. somewhat problematic) attempts to add new content to the article. - DVdm (talk) 22:12, 12 September 2024 (UTC)