Fabulon

I have removed this tradename from the article Polychlorinated Biphenyl as needlessly alarmist. The name is currently applied to several consumer products readily available in Australia, namely an aid to ironing of clothes, and a polyurethane floor sealant, neither of which (presumably) contain PCBs. Doug butler (talk) 00:16, 18 October 2026 (UTC)

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The following discussion has been closed. Please do not modify it.
Quick note: the sentence you removed did carry a source that names the product. It cited Rudel, Seryak & Brody (2008), Environmental Health 7:2 (PMID 18201376). That case study says a resident in one home had "used a floor finish called Fabulon on hardwood floors throughout the 1950s and 1960s", and it traces the PCB content to a 1957 Gleason et al. reference listing for a Fabulon floor finish. Two limits come with it: it is a two-home case study, and the authors say they did not confirm that the floors were the source. So the tradename holds as a sourced, attributed example, but not as a general claim that the brand contains PCBs. You are right that the products using the name in Australia today are a different line. Keeping "wood floor finishes" while naming Fabulon only as the reported case would sit well with that source. AudriaVere (talk) 04:32, 18 October 2026 (UTC)

Liver toxins

An acquaintance died of cholangiocarcinoma today. Based on his recent behaviour and mental condition, medical staff had recently told his family that they believed that the cancer had become sufficiently widespread in his liver that the liver was releasing toxins that were reaching the brain.

I find this a bit confusing. Should I understand that these are toxins naturally present in his food that the liver is supposed to remove, and the liver was simply letting them out because the cancer was overwhelming it? (Since it's bile duct cancer, not liver cancer, I don't suppose the tumours were themselves producing toxic quantities, or toxic types, of bile.) Or if not, is it possible to say what likely caused the situation described by the medical staff? Google searches aren't particularly helpful. Nyttend (talk) 09:43, 18 October 2026 (UTC)

Hepatic encephalopathy. Abductive (reasoning) 11:15, 18 October 2026 (UTC)

Most and least endemic specific

I'm going to express darkly, but the question is serious.

If aliens were to wipe all life from Madagascar, Dozens and dozens of species would be wiped out in the wild. OTOH, if Aliens were to do the same to the US state of Wisconsin, I don't think that any species would be wiped out. Is there any sort of way to measure most and least "precious" areas in that regards. I am guessing least precious" (large areas with the same species would be Antarctica, north Asia, north central North America, and the Sahara.)Naraht (talk) 11:59, 20 October 2026 (UTC)

Stygobromus putealis is the only species that I know of that solely found in Wisconsin. I am certain there are others, but the issue will be that it is rather simple a lifeform to leave Wisconsin and much more difficult to leave Madagascar. And I didn't even think of plants. There is certainly some plant that is only in Wisconsin. ~2026-46630-01 (talk) 12:07, 20 October 2026 (UTC)

The Millennium Seed Bank and the National Center for Genetic Resources Preservation make it difficult to find a plant ONLY in Wisconsin. Any plant of any kind that is known to only exist in Wisconsin is collected and held outside of Wisconsin for preservation. ~2026-46630-01 (talk) 13:12, 20 October 2026 (UTC)

"Any" is a bit much. Our article at Millennium Seed Bank Partnership does not suggest that. The US is a partner and may well have deposited seeds from all species found in Wisconsin, but the MSBP is more UK-centric; its stated goal is to have an exhaustive repository of UK plants, not all plants or all US plants. Matt Deres (talk) 00:42, 21 October 2026 (UTC)

(ec) :Stygobromus putealis: What are we, chopped liver? (Also subspecies Tamias striatus doorsiensis) Clarityfiend (talk) 12:09, 20 October 2026 (UTC)

Megadiverse countries seems appropriate. Biodiversity and endemicity levels (?) are not the same thing, but that article points out that "The main criterion for megadiverse countries is endemism..." so it provides a bit of a start. Matt Deres (talk) 14:43, 20 October 2026 (UTC)

Topic discussed at Endemism#Conservation. -- Verbarson  ^talk_edits 14:54, 21 October 2026 (UTC)

lb st or lb s.t.

In Greene, Warplanes of WW II, the few jet engines of the time are rated in "lb s.t.".

In other aviation books these engines are rated in "lb st".

Pound-forces to measure the thrust, of course (from where the t), but how the s arose? I guess that were measured in standard conditions, i.e. on a ground-fixed device.

Thanks. ~2026-56087-11 (talk) 15:53, 20 October 2026 (UTC)

"S" means "Static" for "Static Thrust." ~2026-46630-01 (talk) 15:59, 20 October 2026 (UTC)

Thanks ~2026-56087-11 (talk) 21:29, 20 October 2026 (UTC)

Biology, Chemistry, and Physics being taught in High Schools, but not Astronomy

Why are school subjects, like biology, chemistry, and physics, always taught in high schools, but not other types of science, such as astronomy, ecology, geology, oceanography, and zoology?

I remember this in high school in 2019, when enroll in classes for the first time, it was that I discovered that the subjects that are taught in science, are only 3 of them. I was wondering that if more additional sciences are in the educational curriculum. Furthermore, what I have learned in science classes, could add more subjects, such as applied, material, and political sciences. Plus, attending high school is only for 4 years, and I graduated after this. ~2026-56457-42 (talk) 06:46, 22 October 2026 (UTC)

I think you can theoretically argue that astronomy is an extension (or specialization) of physics, while ecology, geology, oceanography and zoology being specialized fields of biochemistry. 海盐沙冰 _{/ aka irisChronomia / Talk / Uploads} 06:57, 22 October 2026 (UTC)

To say this another way: in order to understand astronomy one first needs to understand basic physics, to systematically explore living beings across different biospheres one first need to know about how animals and plants work.

An interesting note is that in Mainland China, geography is part of the junior highschool curriculum. 海盐沙冰 _{/ aka irisChronomia / Talk / Uploads} 07:07, 22 October 2026 (UTC)

Astronomy is part of physics, ecology and zoology are part of biology, geology and oceanography are part of geography (at least for school purposes). Physics, biology and geography are normal school subjects in most countries. I don't know about your country though; you didn't mention where you are. School systems vary widely. PiusImpavidus (talk) 08:55, 22 October 2026 (UTC)

Why is poetry not a class? Because it's not the base field. Also, qualified astronomy high school teachers don't grow on trees. (Mind you, my sister's high school science teacher told her that friction was perpendicular to the direction of motion.) Clarityfiend (talk) 11:56, 23 October 2026 (UTC)

From a practical point of view, a lack of basic understanding of biology, chemistry, or physics might kill you. The same is unlikely to be true of astronomy. Which is not to say that some astronomy should not be taught in schools, but it may help explain priorities. AndyTheGrump (talk) 12:07, 23 October 2026 (UTC)

I think we need to teach "history of science and pseudoscience" in school, then. 海盐沙冰 _{/ aka irisChronomia / Talk / Uploads} 13:10, 23 October 2026 (UTC)

I wouldn't disagree, though I suspect any such proposal would run into a great deal of opposition. AndyTheGrump (talk) 13:32, 23 October 2026 (UTC)

...Good that we have Wikipedia as a fallback. 海盐沙冰 _{/ aka irisChronomia / Talk / Uploads} 13:35, 23 October 2026 (UTC)

Also the law of supply and demand applies. It's hard enough to get students to take general science classes. One that provides even less future job potential just isn't going to draw them in. Clarityfiend (talk) 13:23, 23 October 2026 (UTC)

High school covers more general topics. In college / university, you get more specifics. ←Baseball Bugs ^{What's up, Doc?} carrots→ 13:41, 23 October 2026 (UTC)

High school is not only general, but highly limited. There is an old representation of that that has been copied many times (everyone claims they came up with it). Make a tiny dot on a piece of paper. If the paper is all possible knowledge, that tiny dot is what you learn in high school. Draw a tight circle around it. That is the knowledge you gain in a four-year college degree. Make a smudge next to the dot. That is a specialization focus for a masters degree. Now, draw a line all the way to the edge of the paper. That point where it touches the edge and a few bits of graphite hang off the edge... that's the PhD. ~2026-46630-01 (talk) 13:58, 23 October 2026 (UTC)

Within that first dot are microdots, which are the things you learn in elementary school and middle school. It's all a "layering" process. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:08, 23 October 2026 (UTC)

Physics and chemistry serve as the foundation for other scientific disciplines, providing the universal principles that govern how matter, energy, atoms, and forces function. Without these fundamentals, it would be impossible to gain a deep understanding of the mechanisms at work in more advanced scientific fields. Stanleykswong (talk) 21:51, 23 October 2026 (UTC)

I remember having the option to study Geology at my school (in the UK in the 1980s), though it wasn't an option that I took up. in solidarity Chuntuk (talk) 20:09, 26 October 2026 (UTC)

Geography or geology? Stanleykswong (talk) 09:21, 27 October 2026 (UTC)

Geology is a "hard" natural science that requires a deep grasp of mathematics, chemistry, and physics; geography, by contrast, is relatively more accessible, as it encompasses a broader—and often more superficial—synthesis of both the social and natural sciences. Stanleykswong (talk) 09:27, 27 October 2026 (UTC)

If anyone has refs for these big-three being either the most common or the most fundamental, please add to Science education#Fields of science education could use some help. DMacks (talk) 11:31, 27 October 2026 (UTC)

Measurement of a light wavelength

How was it possible to measure a wavelength of light in the visible spectrum for the first time? Malypaet (talk) 22:17, 23 October 2026 (UTC)

Newton's rings provide a means of determining the wavelength and were known in 1665 - so perhaps the first method. catslash (talk) 22:33, 23 October 2026 (UTC)

But it seems that nobody actually calculated the wavelength until Young did so in 1801 (which seems like quite a lot later). catslash (talk) 22:52, 23 October 2026 (UTC)

Interestingly, Young admits that he did indeed obtain these first experimental values for optical lengths without carrying out a single experiment. He even invites his readers to place all the more confidence in his results precisely because they were deduced from experiments that were neither conceived, nor carried out, within the framework of his own theory. It is actually well known that in his Opticks, Newton extensively described and analysed the coloured rings...

— Morizot, Olivier (2026). "The wavelength of light as Thomas Young invented it". Archive for History of Exact Sciences. 80 (1).

so consider yourself correct for both. fiveby(zero) 23:12, 23 October 2026 (UTC)

Young's observations, in particular his double-slit experiment, presented in the same 1801 paper as his explanation of Newton's rings in terms of wave interference, heralded the beginning of the end of the corpuscular theory of light, which until then had been dominant. Eighteenth-century scientists mostly did not believe light wavelengths were a thing, or else might not want to damage their careers by appearing to be adherents of a fringe theory.  ​‑‑Lambiam 08:47, 24 October 2026 (UTC)

Presumably an interference fringe theory... Mike Turnbull (talk) 12:09, 24 October 2026 (UTC)

Climate monitoring

Before formation of the Copernicus Climate Change Service in 2014, were there any Europe-based climate monitoring agencies that would publish a monthly and annual global and regional weather summary like how Copernicus Climate Change Service now does? There were NOAA and NASA, but were there any European ones? ECMWF was founded already in 1979, but it has only forecasted anomalies, not observed anomalies. Were there any reports comparable to European State of The Climate until then? --40bus (talk) 21:49, 24 October 2026 (UTC)

There were, in two forms. First, the WMO — an intergovernmental organization headquartered in Geneva — publishes its annual Statement on the status of the World Climate, which details global, regional and national temperatures and extreme weather events; that is the closest analogue to today's European State of the Climate. Second, the Hadley Centre, together with the University of East Anglia's Climatic Research Unit, has long maintained the HadCRUT global temperature series, with monthly and annual updates issued by the Met Office. On the ECMWF point, the premise is not quite right: ECMWF has produced observation-based reanalyses well before 2014 — ERA-Interim, covering 1979 to 2019, works by integrating historical meteorological observations onto a regularly spaced global grid, so it is built from observed data rather than forecasts. Its successor ERA5 was released as part of the Copernicus Climate Change Service. What changed in 2014 was the packaging — a single service producing press-facing monthly and annual summaries with commentary — not the existence of the underlying observed-data products. --SaoriWalks (talk) SaoriWalks (talk) 00:34, 25 October 2026 (UTC)

Were there any other services producing press-facing monthly and annual summaries from Europe with commentary before that? --40bus (talk) 05:47, 25 October 2026 (UTC)

Yes, though none packaged quite like Copernicus does now. The clearest examples:

• The WMO (headquartered in Geneva) has published its annual Statement on the Status of the Global Climate well before 2014 — the WMO e-library holds editions for at least 2003, 2005 and 2013 — and each edition was announced with press coverage, e.g. the 2013 statement announced in March 2014 and covered by Reuters and The Guardian with quotes from then secretary-general Michel Jarraud. It covers global, regional and national temperature with commentary, so it is the closest pre-2014 analogue to a press-facing annual summary from a Europe-headquartered body.
• The Met Office issued dated monthly press-facing commentary on global temperatures before 2014, e.g. the "Met Office in the media" blog post of 29 January 2012 (now archived on their site) and the 2013 "recent pause in warming" research news page. The joint Met Office/CRU annual global temperature press releases are the same tradition, e.g. "Data shows 2016 likely to be warmest year yet" (18 January 2017).
• National services such as Germany's DWD and Météo-France publish annual national climate summaries with commentary, but those are regional rather than global. I could not verify a specific dated example today, so take that part as unconfirmed.

What was genuinely new in the Copernicus era was the packaging: a single service producing both monthly and annual press bulletins with commentary on a fixed schedule. Before 2014 the annual summaries were routine (WMO, Met Office), while monthly press-facing commentary was occasional rather than packaged. --SaoriWalks (talk) 09:10, 25 October 2026 (UTC)

Another question: Does Canada have any national monthly and annual summary similar to how NOAA has for the US? --40bus (talk) 10:07, 25 October 2026 (UTC)

Yes. The Canadian counterpart of NOAA is Environment and Climate Change Canada (ECCC), and its Climate Trends and Variations Bulletin (CTVB) is the direct analogue of NOAA's national reports. Each bulletin summarizes the national average temperature (and precipitation) for the period, sets it in historical context over the full length of the ECCC climate record, and highlights notable regional deviations. Editions are published for each season and for the year as a whole, e.g. the Annual 2024 and Spring 2025 editions are listed on the ECCC website. Unlike NOAA's monthly National Climate Report, the packaged CTVB editions are seasonal and annual rather than monthly; monthly national temperature figures are published as data rather than as a commentary bulletin, though I could not verify the exact historical cadence of the older editions from here, so take that last detail as unconfirmed. --SaoriWalks (talk) 21:55, 25 October 2026 (UTC)

Long run behavior of open quantum fields

When a wave function evolves unitarily in an open quantum system, as described in Quantum_decoherence#Loss_of_interference_and_the_transition_from_quantum_to_classical_probabilities; it is quite easy to convince yourself that the system will spend an equal amount of time in each classical state over the long run if the quantum state belongs to a finite dimensional Hilbert space (such as a system of qubits). I assume this would also hold if the classical state is parameterized by a finite number of particle co-ordinates (as in ordinary quantum mechanics), as this justifies the fundamental assumption of statistical mechanics that all microstates are equally probable. But does this property fail to hold when the wave function is over field configurations, as in quantum field theory? ~2026-56897-11 (talk) 14:16, 25 October 2026 (UTC)

Speaking with almost total lack of comprehension of the theoretical background, doesn't the fact that photons manage to keep plodding on for billions of years through noisy space imply that the photon wave function manages to remain coherent also in an open system?  ​‑‑Lambiam 08:52, 26 October 2026 (UTC)

Two corrections to the premise first, because the equal-time intuition is doing more work than it can hold. Unitary evolution alone does not imply spending equal time in each classical state - in fact a perfectly unitary flow never equilibrates at all. Unitary evolution on a finite-dimensional Hilbert space is reversible and has no attractors: the state vector simply rotates, and any "time spent in state X" picture only emerges after coupling to an environment (decoherence) plus specific assumptions about the resulting mixture. The equal a priori probability postulate of statistical mechanics is not usually derived from time averages of wave function components either; the standard justification is Liouville's theorem - Hamiltonian flow preserves volume in phase space, so the natural invariant measure on the energy shell is uniform.

On the actual question about fields: yes, the property fails, and for reasons that appear already at the level of the configuration space. The space of field configurations is infinite-dimensional, so there is no normalizable uniform measure over it to average over at all - the well-defined analogues are the Gaussian free-field measures and their interacting deformations, which is the territory of constructive quantum field theory. And even setting that technicality aside, long-run equal exploration typically fails in QFT for physical reasons: theories can decompose into superselection sectors that no unitary evolution connects, gauge theories have topological sectors (see instantons in Yang-Mills theory) between which tunneling is exponentially suppressed, and integrable field theories are famously non-ergodic. So the equal-time property already fails for interacting finite systems in general, and fails even more dramatically for fields. --SaoriWalks (talk) 2026-, 26 October 2026 (UTC)

How does it fail for interacting finite systems? ~2026-56897-11 (talk) 12:58, 28 October 2026 (UTC)