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January 12

Eastern or Western Grey Squirrel

Hello. I just looked on Commons through the category for Sciurus vulgaris. However, in there I found photos of either an Eastern or Western Grey Squirrel. I initially changed the category to Sciurus carolinensis, however, as the image was taken in the state of Washington, it could also be Sciurus griseus. According to https://wdfw.wa.gov/species-habitats/living/species-facts/tree-squirrels# six squirrels types can be found in Washington: Tamiasciurus douglasii, Tamiasciurus hudsonicus, Sciurus griseus, Glaucomys sabrinus, Sciurus carolinensis, Sciurus niger. I just want to correct the categories because it is certainly not Sciurus vulgaris.

Images by Joe Mabel on Commons

There are more images in c:Category:Sciurus vulgaris eating apples. --Christian140 (talk) 07:20, 12 January 2021 (UTC)[reply]

If I had to make a guess, I would say it's the eastern Sciurus carolinensis, because of the red fur on the face and haunches. Confirmed pictures of the western Sciurus griseus don't show such red fur; they're entirely shades of gray. A quick google search of "Eastern Gray Squirrel" and "Western Gray Squirrel" will easily confirm.--Jayron 32 14:34, 12 January 2021 (UTC)[reply]

The wdfw.wa.gov site (linked above) notes that the eastern gray was "introduced in Washington in the early 1900s. Since then they have been repeatedly released in parks, campuses, estates, and residential areas. They are now the most common tree squirrels in urban areas." Since the photos were (per file description) taken "near the Ceramic and Metal Arts Building, University of Washington", I'd go with Sciurus carolinensis, and include a note that the eastern gray is an introduced species. 107.15.157.44 (talk) 16:40, 12 January 2021 (UTC)[reply]

The site further describes Eastern Grey Squirrels as: "The upper parts of the Eastern gray squirrel are gray with a reddish wash in summer; its underparts are whitish. It’s about 20 inches long, half of which is its prominent, bushy tail."

And Western: "hey are steel gray on the back, with contrasting white on the belly and throat, resulting in the name, "silver gray squirrel" in some parts of their range. They are distinguished by their very long and bushy tails that are primarily gray with white-frosted outer edges. They also have prominent ears, which can be reddish-brown on the back in winter."

However, there are also these images of Western Grey Squirrels, one comparison, which make them seem very similar to me:

Western
Eastern and Western

--Christian140 (talk) 15:03, 13 January 2021 (UTC)[reply]

Taxidermic specimens may not be the best exemplars, especially when there are thousands upon thousands of available photographs of such squirrels available across the internet that can easily be located. Googling the names shows the differences much more readily than does focusing on a single stuffed specimen or two. It's very easy to tell by comparing images that the OP's pictures are of the eastern, and not western, gray squirrel by doing so. --Jayron 32 15:11, 14 January 2021 (UTC)[reply]

January 13

How can catalyst can speed up chemical reaction without participating in it?

How can catalyst can speed up chemical reaction without participating in it? Rizosome (talk) 02:33, 13 January 2021 (UTC)[reply]

Catalysts do participate in the reaction but they aren't consumed by the reaction.Dja1979 (talk) 06:37, 13 January 2021 (UTC)[reply]

With enzymes (which are biological catalysts), the enzyme typically binds covalently to the reactants at the active site. When the reaction finishes, the products unbind; this is often caused by the enzyme changing shape. A lot of inorganic catalysts work by adsorbing the products onto their surface, which brings the products close together and holds them there so they react with each other. A good example is the Haber–Bosch process. --47.152.93.24 (talk) 01:29, 15 January 2021 (UTC)[reply]

In a letter published in 1957 in Nature, Lionel and Roger Penrose described a very simple mechanical analogue of self-replication.^[1] (demo videos: [2], [3]). I wonder, has anyone tried to construct a mechanical analogue of catalysis, with say three shapes A, B and C, where A and B can interlock and where C facilitates this? So a collection of A and B shapes, when shaken, should interlock at a certain low rate just by chance, but adding some C shapes should speed this up, while the C shapes disengage when an A and B shape interlock so that they can continue their matchmaking. --Lambiam 12:37, 15 January 2021 (UTC)[reply]

Is there any references about ionic insulators?

In the article ionic compound, there is a sentence "As solids they are almost always electrically insulating, but when melted or dissolved they become highly conductive, because the ions are mobilized." Is there any references about it? Such as determination of electrical resistance of solid ionic compounds, or some exceptions. --Leiem (talk) 03:01, 13 January 2021 (UTC)[reply]

Thank you. --Leiem (talk) 09:25, 15 January 2021 (UTC)[reply]

Why so much commercial cultivation of oil-palm in Southeast Asia, and so little in West-Southwest Africa?

I gather that oil-palm plantations in southeast Asia are often highly controversial, given the deforestation and other environmental damage they can involve. It's essentially an invasive species,

My question is twofold: According to our article on Elaeis guineensis, the plant is native to west and southwest Africa.

1. Given that in west-southwest Africa it's a native species, wouldn't you expect to see a significant chunk of the world's palm-oil production come from this region? Why is so much of the stuff produced in Indonesia and Malaysia, and so little in Angola, The Gambia, Senegal, or Ivory Coast?

(There may be issues with these countries in Africa being politically unstable, but this doesn't seem to have significantly hampered other resource exploitation in the region, such as cobalt or cacao).

2. Would cultivation in the regions of Africa where the tree is native likely be more sustainable and do less environmental damage than Indonesian and Malaysian cultivation, all else being equal? If this were the case, surely environmental activists would or should be encouraging these (African) countries to increase their production, to replace the Southeast Asian production?

EDIT: My question is about commercial-scale production, not local subsistence-level production for local consumption. Eliyohub (talk) 06:26, 13 January 2021 (UTC)[reply]

The main reason oil-palm plantations are controversial – next to the exploitation of the workers – is that they are created by the large-scale destruction of rainforest, replacing it by a monoculture, often also appropriating grounds depriving the local population of a livelihood based on crop cultivation. There is no reason to assume the external cost would be any less in areas where the palm is native. As to why there are not more African oil-palm plantations, perhaps there are historical and cultural reasons why there are not more African plantations in general, such as for bananas. Africa accounts for only 10 percent of the global total of forest plantations. [FAO. Global Forest Resources Assessment 2005, Forestry Paper No. 147. Rome, 2006.] Cocoa plantations appear to be an exception; Africa amounts for about half of global cacao production. --Lambiam 07:56, 13 January 2021 (UTC)[reply]

It should also be noted that much if not most of the worlds crops are grown extensively in areas outside of their "native" pre-civilization regions. Honestly, I would be surprised to find a crop where the worlds largest producing regions were the native regions still; I'm sure there are some, but I would never consider there to be enough for it to ever be an expectation. Some examples: Almonds are native to Iran; the world's largest almond producer by far is California. The tomato is native to the pacific coasts of Central and South America. List of countries by tomato production shows that by far the largest producers of the tomato are in Asia (China, India, and Pakistan). Sugarcane, the world's most produced crop, is native to South Asia. The largest producer by far is Brazil. You can repeat this game for lots of crops; the point is that one should disavow oneself of the expectation that because a crop is "native" to a region, that region is the likely place it is farmed. That's not a thing. Whether or not it should be a thing (for any given justification of "should") is a different question. --Jayron 32 15:06, 14 January 2021 (UTC)[reply]

@Eliyohub:, Industrial palm oil investors struggle to gain foothold in Africa says:

"During the late 2000s and early 2010s, some African governments were quick to propose their forested regions as the solution. In what was dubbed the “great African land rush,” some of the world’s largest palm oil producers signed deals across the continent. Many of those deals were massive; in Liberia, for example, concession agreements held by just two companies covered nearly 600,000 hectares (1.5 million acres)...

"...the key factor, the report says, is pushback by communities affected by the projects. Few of the companies that wanted to move into Africa had a plan for a fundamental problem: tens of thousands of people already lived on the land they’d leased. The land deals were often negotiated in near-secrecy and few local communities were consulted by their governments before their territory was offered up to investors; when the bulldozers arrived, trouble followed".

Alansplodge (talk) 16:27, 14 January 2021 (UTC)[reply]

Ffp3 mask

What does ffp stand for As in face mask — Preceding unsigned comment added by 86.24.168.231 (talk) 21:18, 13 January 2021 (UTC)[reply]

Filtering face-piece.[4] ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:07, 13 January 2021 (UTC)[reply]

Thx — Preceding unsigned comment added by 86.24.168.231 (talk) 03:55, 14 January 2021 (UTC) Er, wait I read the link It doesn't say that — Preceding unsigned comment added by 86.24.168.231 (talk) 04:03, 14 January 2021 (UTC)[reply]

The second paragraph includes "Recently, it has been recommended by the Royal College of Ophthalmologists (RCOphth) and the British and Eire Association of Vitreoretinal Surgeons (BEAVRS) that we use filtering face-piece (FFP)3 masks during vitrectomy surgery in all patients, in addition to eye protection related to the potential for aerosol production [1]. " — Preceding unsigned comment added by Baseball Bugs (talk • contribs) 05:38, 14 January 2021 (UTC)[reply]

We have an article on FFP standards. DuncanHill (talk) 17:53, 14 January 2021 (UTC)[reply]

"Sub-" in geography

Is there a specific, commonly accepted, meaning given to the prefix "sub-" as used in geography? I know it literally means "below" or "under", but what does it means in words like "subpolar", "subtropical" or "sub-Saharan"? Subpolar regions are on lower latitudes than (so, in a sense, "below") the poles, but then, subtropical regions are on higher latitudes than the tropics (so why not "supertropical"?). Could it mean "outside", with the subpolar regions being around the poles, the subtropics being on either side of the tropical zone and sub-Saharan Africa being most (but not all) of Africa outside the Sahara? — Kpalion^(talk) 21:27, 13 January 2021 (UTC)[reply]

The "Indian sub-continent" does not refer to India etc being located below the rest of central Asia but to its being smaller than a continent proper. -- Jack of Oz ^{[pleasantries]} 22:30, 13 January 2021 (UTC)[reply]

The prefix can mean in general three different things: under, beneath as in sub-saharan or subculture; subsidiary, secondary als in sub-continent or subroutine; and almost, nearly, approximately, somethling less as in subtropical, subarctic, subequatorial or subclinical, see e.g. en.wiktionary.org, merriam-webster.com 2003:F5:6F0C:8700:988A:3855:258A:E6D9 (talk) 23:12, 13 January 2021 (UTC) Marco PB[reply]

Okay, the third meaning (something less) makes sense for subpolar, subtropical and subcontinent. But how does the first meaning (beneath) make sense for Sub-Saharan Africa? It only would, if it were located underground, buried beneath the Sahara. — Kpalion^(talk) 23:31, 13 January 2021 (UTC)[reply]

Sub-Sahara is south of the Sahara, hence "under" the Sahara on a typical map. ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:17, 14 January 2021 (UTC)[reply]

I just came across suboceanic, which I think means "inland". Abductive (reasoning) 08:51, 14 January 2021 (UTC)[reply]

No, it means "beneath the ocean floor". ←Baseball Bugs ^{What's up, Doc?} carrots→ 09:32, 14 January 2021 (UTC)[reply]

Not always, you should check. Abductive (reasoning) 19:50, 14 January 2021 (UTC)[reply]

I googled the term and that's what I found. Can you find another definition? ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:52, 14 January 2021 (UTC)[reply]

Influence of Site and Stand Factors on the Distribution of Crustose Lichens of the Caliciales in a Suboceanic Spruce Forest Area in Central Norway. Abductive (reasoning) 01:50, 15 January 2021 (UTC)[reply]

Of course, map orientation is arbitrary, so there's no logical reason to equate "south" with "down". But then, not all terminology has to be logical. Can you think of any other examples where "sub-" is used to mean "south of"? — Kpalion^(talk) 10:00, 14 January 2021 (UTC)[reply]

In England (specifically, not the rest of the UK) during the 13th and 14th centuries, after the Normans had taken over, Latin (as well as Norman-French) elements were sometimes added to Anglo-Saxon place names to clarify geographical locations, and hence ownership, for the educated, Latin-literate overlords and their clerics: one of the elements was sub, such that a village X (say) might be named "X sub Y" to indicate its position relative to Y (thus distinguishing it from other places also called X. (Another such element was cum when, for example, two villages were combined into a single parish or other administrative unit, such as Prestwich-cum-Oldham.) Whether or not the "sub" indicated relative altitude, or distance "down" a river, or that X was south of Y, I don't know, but someone with access to a database gazeteer and with the requisite search skills might be able to investigate the question. {The poster formerly known as 87.81.230.195} 90.200.40.9 (talk) 14:06, 14 January 2021 (UTC)[reply]

There is the idiom go south for taking a "downward" turn – a turn for the worse. --Lambiam 11:09, 14 January 2021 (UTC)[reply]

That's true, but I don't suppose geographic terminology is based on English idioms. — Kpalion^(talk) 12:32, 14 January 2021 (UTC)[reply]

The very term we're examining suggests that some may be. At least it's not called Darkest Africa any more. Matt Deres (talk) 14:21, 14 January 2021 (UTC)[reply]

The phrase "go south" is an example of the opposite phenomenon: English idiom based on geographic terminology. --Khajidha (talk) 15:57, 14 January 2021 (UTC)[reply]

As are the phrases "up North" and "down South" commonly used in England, which amusingly seem to conflict with the railway-related usage of always going "up" to London. (The latter allegedly derives from the earliest railways, for coal waggons which free-ran downhill from the mineheads to the riverside coal staithes and were then horse-hauled back up to the mines where the companies involved had their hedquarters. {The poster formerly known as 87.81.230.195} — Preceding unsigned comment added by 90.200.40.9 (talk) 17:18, 14 January 2021 (UTC)[reply]

In a few places, the term "down East" is used in the US (Maine and North Carolina), and confusing to outsiders "down Cape" is towards Provincetown when on Cape Cod, which depending on which part of the Cape you're on is either east or north. And, of course, "down the river" depends entirely on which direction the river in question is flowing. --Jayron 32 19:58, 14 January 2021 (UTC)[reply]

Specific to sub-Saharan, see here. First known use was 1899, and it is explicitly referring to "South of" rather than "lower in altitude" or "under". Also, remember that language is neither consistent nor logical. It is often enough to confuse you into thinking it should be, but one should never have the expectation that it must be. The fact that south really isn't "down" in any meaningful sense except by convention of the way maps are hung on walls, doesn't mean people don't use the terminology equating south to down in their language. Doing so is only wrong in the annoyingly pedantic sense, and so long as everyone speaking already understands the context, it's really not a problem. And once people who don't know the context have it explained to them, they no longer have an excuse for being confused. --Jayron 32 14:57, 14 January 2021 (UTC)[reply]

I must say I didn't expect logic and consistency in everyday expressions like "go south", but I did in scientific terminology. But I take it that even this expectation was wrong. Thanks to all for your answers. — Kpalion^(talk) 18:32, 14 January 2021 (UTC)[reply]

Sub-Saharan is not scientific terminology; consistency in scientific terminology only occurs in very specific situations where there is an active standards body that publishes and enforces such standards, such as the IUPAC for Chemistry nomenclature; still even so some non-standard terminology persists in chemistry literature, such as acetic acid instead of the formal "ethanoic acid". Even highly specialized terms like entropy have similar but non-overlapping meanings from different fields. Language consistency is constantly confounded by real humans, who keep using it the wrong way. Sorry about that. --Jayron 32 18:53, 14 January 2021 (UTC)[reply]

January 14

obese people to lie down on their sides

What's the scientific explanation for the fact it's difficult for obese people to lie down on their sides? Is it just about turning the body or also because of some physiological mechanical issues that don't enable them to lie down on their sides?ThePupil (talk) 00:13, 14 January 2021 (UTC)[reply]

What's the basis of your premise? ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:15, 14 January 2021 (UTC)[reply]

I don't know if this is an alleged fact or a common recommendation or what. I have seen, with some amazement, that COVID-19 patients who have serious breathing problems are better off when turned on their bellies.^[5] I guess this has experimentally been proven to help (and not just in theory), but doesn't a prostrate position make breathing harder for obese patients? --Lambiam 11:01, 14 January 2021 (UTC)[reply]

It is a proven and practiced manoeuvre. See here, not specifically Covid19 patients but discusses the advantages of nursing obese patients in the prone position. Richard Avery (talk) 12:23, 14 January 2021 (UTC)[reply]

If they're quite heavy, as with the OP's question, wouldn't lying on their bellies inhibit breathing? ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:51, 14 January 2021 (UTC)[reply]

Did you read the paper linked to? --Lambiam 12:03, 15 January 2021 (UTC)[reply]

Animals with Milk Production at Upper end of Torso rather than Lower.

For Humans, breasts are at the "Upper" end of the Milk line (closest to the head) and for Cows (and I guess most other Mammals), the udder (with at least two sets of active nipples) is at the lower end of the Milk line at the udder. Two questions. 1) Does milk production at the upper end of the Milk Line correspond to Mammals with hands (like the other apes) so that the babies can be carried and nursed? 2) Are there any animals where the Milk production is at the upper end of the body but it is standard to have more than one active nipple on each side? (seems like standard is either one set of nipples close to the head or at least two sets close to the groin) Naraht (talk) 14:21, 14 January 2021 (UTC)[reply]

@Naraht: Elephants have breast and it's located at the fore part of their torso, at a chest. --CiaPan (talk) 14:44, 14 January 2021 (UTC)[reply]

I'm not sure there is any strict pattern, but there may be based on some large grouping (i.e. specific class or family or grouping of genuses or something like that). For example, cats and pigs have teats that are fairly centrally located; I would describe neither as "upper" (as in humans) or lower (as in cattle), and other than being "mammals" I can't think of any commonality between cats and pigs in terms of taxonomy. --Jayron 32 14:50, 14 January 2021 (UTC)[reply]

Litter size? Cats and pigs tend to have larger litters than people (or cattle), though that could simply be coincidence. In very broad terms, it seems like it should be logistically easier to nurse a litter if the teats are not tucked at one end. Matt Deres (talk) 15:16, 14 January 2021 (UTC)[reply]

Possibly, but that still doesn't explain why cattle nurse near the back legs and elephants nurse near the front legs. --Jayron 32 15:35, 14 January 2021 (UTC)[reply]

You are assuming that there is a reason. Both variants are obviously functional, which one developed in which lineage of mammals may be more or less random. Obviously, once established, the pattern is unlikely to virtually the point of impossibility to reverse itself. For example, descendants of modern humans are unlikely to switch to udders at or near the waist. --Khajidha (talk) 15:47, 14 January 2021 (UTC)[reply]

If you're using the word "you" to refer to myself, then quite the contrary. I've been arguing very hard that there is no reason, by providing counterexamples and the like. Perhaps you were confused when I stated "I'm not sure there is any strict pattern." You see, what I meant by that was that I wasn't sure there is any strict pattern. I hope that clarifies things for you. --Jayron 32 15:54, 14 January 2021 (UTC)[reply]

No, I just got confused because I didn't notice that the same poster (you) had said both "I'm not sure there is any strict pattern" and "that still doesn't explain why cattle nurse near the back legs and elephants nurse near the front legs". --Khajidha (talk) 16:50, 14 January 2021 (UTC)[reply]

(EC) Broadly agree, but if lactation only evolved in mammals once (closest article seems to be this and links from it, but it doesn't address this point directly) then mammals have switched strategies. I don't think it's crazy to assume that this happened due to evolutionary pressure, but we'd just be guessing as to what those pressures might be. Litter size may play a part, but so could overall body shape, locomotion method, and other factors. There are probably several. I threw out litter size in my reply to Jayron only in answer to what cats and pigs have in common that people and cows don't and even that came with a question mark. Matt Deres (talk) 16:58, 14 January 2021 (UTC)[reply]

Somewhat obviously, delivering a large litter size has an energy cost, which would be wasted if half the litter dies for lack of teats to feed them, but an excess of milk-producing teats also has its cost, so evolutionary pressure will tend to correlate the number of milk-delivering teats with litter sizes. --Lambiam 11:49, 15 January 2021 (UTC)[reply]

Yes, lactation evolved once, but that is not what is at question here. The earliest mammals would have had multiple teats all along the milk line. In various lineages some of these teats have been "lost". Humans simply no longer regularly develop mammary glands and nipples further down the torso and cows no longer regularly develop nipples closer to the head. --Khajidha (talk) 17:30, 14 January 2021 (UTC)[reply]

Humans occasionally develop supernumerary nipples further down the torso; if there were any evolutionary advantage to these, they might catch on. Alansplodge (talk) 12:19, 15 January 2021 (UTC)[reply]

If it evolved once, that implies that something drove it to be expressed differently in different groups. It doesn't have to be due to pressures, of course, but if the ancestor mammal developed, say, mid-torso lactation, then it's not unreasonable to assume that evolutionary pressures caused later lineages to deviate from that. Matt Deres (talk) 12:52, 16 January 2021 (UTC)[reply]

Well, yes, but that's not what you seemed to be saying earlier. You previously mentioned switching strategies, which I took to mean switching from front lactation to rear lactation (or vice versa). What you are now describing (and what I was saying) is the specialization from lactation along the torso generally to localizing lactation in the front (or rear). Some lineages specialized one way, some the other. And some retained nipples all along the torso. No switching, only specialization. --Khajidha (talk) 20:45, 17 January 2021 (UTC)[reply]

Cows, horses, sheep, etc (with udders between their rear legs)seem to be able to lick their babies while they suckle, elephants have a much less flexible body so they can only fondle their babies with their trunks while the babies are suckling from the nipples in their "armpits" 49.197.29.242 (talk) 07:10, 17 January 2021 (UTC)[reply]

Mask with Ag+

I've bought a face mask with Ag+ ions for antimicrobial properties (at least per its description) and after about 25 minutes of wearing started to feel a slight salty taste in the mouth, as if saliva became mildly salty. Is it because of those silver ions or sort of a placebo-like illusion? 212.180.235.46 (talk) 22:07, 14 January 2021 (UTC)[reply]

One of the reasons that silver cutlery is useful is because although antimicrobial, it has no taste. See Silver#Jewellery_and_silverware. I can't explain your specific experience. Mike Turnbull (talk) 13:21, 15 January 2021 (UTC)[reply]

January 15

Healthcare Visit Frequency Notation

I was looking over some home health care paperwork and came across some references to a visit frequency of "2w9" and another for "1w/1w". I searched the web and believe that "2w9" means twice a week for 9 weeks, but haven't found an explanation for the "1w/1w" case. Is there a standard or reference out there somewhere that defines or describes this notation?. Thnks. --Tom N talk/contrib 02:57, 15 January 2021 (UTC)[reply]

I can't find anything for "1w/1w" either. Could it be a typo or variant for 1w1? See https://allnurses.com/what-mean-t440055/ --Khajidha (talk) 03:26, 15 January 2021 (UTC)[reply]

When I contacted the source, I was told that this was intended to mean 1 visit per week for 1 week (i.e., one visit total). I don't think the notation is correct, but don't have a source for that. -- Tom N talk/contrib 02:43, 16 January 2021 (UTC)[reply]

Christmas tree recycling

What do they do with Christmas trees once they're no longer needed? How are they recycled, and what are the end products? 2601:646:8A01:B180:F84D:6B4F:9537:7CB5 (talk) 04:12, 15 January 2021 (UTC)[reply]

This site discusses recycle options for various localities in Virginia and indicates that most trees are shredded to produce mulch. I expect this is also common elsewhere. Another site from the Arbor Day Foundation shows a few other options. In beach communities, discarded Christmas are also used to help build up sand dunes as described here. -- Tom N talk/contrib 04:32, 15 January 2021 (UTC)[reply]

It's done in England too. At about the 17 minute mark of this "Escape to the Country" episode,[6] they discuss preservation of sand dunes in Lancashire. ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:13, 15 January 2021 (UTC)[reply]

How your old Christmas tree can be used to regenerate dune environments. Alansplodge (talk) 12:10, 15 January 2021 (UTC)[reply]

I saw a CTV News report a day or two ago about a park in or near Montreal, where they had set up boxes to serve as tree stands and invited people to bring their trees there after removing the decorations. The idea was that the public would be able to visit them outdoors for a few weeks and then they would be recycled in the usual way. Apparently many people left cards in the trees with messages of hope for the new year. Unfortunately, I can't find a link to the story now; I don't know the name of the place, and my searches are swamped with other news about Christmas trees. --142.112.149.107 (talk) 06:19, 15 January 2021 (UTC)[reply]

Found it. The park is Jarry Park and the project is called "the ephemeral forest". News reports: [7] [8] [9]. --142.112.149.107 (talk) 05:45, 16 January 2021 (UTC)[reply]

At least in some places they are used to make biomass (i.e. fuel for power stations); see Biomass One recycles Christmas trees to fuel biomass power plant which refers to an enterprise in Oregon. I suspect that this is more likely in areas with a large forestry sector, where the conversion of off-cuts and brush to biomass is already being done. Alansplodge (talk) 12:10, 15 January 2021 (UTC)[reply]

"Christmas trees can be collected, put into anaerobic digesters, and used as the source material for biogas". [10] Alansplodge (talk) 16:06, 15 January 2021 (UTC)[reply]

Where I live, they'll take them at the local landfill, where they turned into garden mulch. When I was growing up, we used to just yeet them into the woods behind our house. Within 4-5 years they decomposed into the soil. Shortly after I got married, we decided to get an artificial tree. We've had the same one for like 17 years now, and it doesn't show any signs of needing to be replaced. --Jayron 32 13:33, 15 January 2021 (UTC)[reply]

The great Christmas tree debate: Are real or fake firs better for the environment? says: "...if you have an artificial tree, you would need to use it for at least 10 years in order for its environmental impact to equal that of a responsibly-disposed natural tree". Alansplodge (talk) 16:03, 15 January 2021 (UTC)[reply]

I think we've made it worth it, then. We're not looking to get rid of it anytime soon, either. --Jayron 32 19:28, 15 January 2021 (UTC)[reply]

For many years Mum had a live tree in a pot, that lived out on the decking for most of the year and came in for Christmas. When it got too big to move we would decorate it outside. DuncanHill (talk) 20:48, 15 January 2021 (UTC)[reply]

In northern Michigan, trees are used to mark the safe path for snowmobiles across the ice between Mackinac Island and the mainland. [11] Rmhermen (talk) 02:26, 16 January 2021 (UTC)[reply]

Why did CERN invent WWW?

CERN is operates the largest particle physics laboratory in the world. Why did CERN move into computer science from particle physics? Move into computer science I mean inventing WWW etc Rizosome (talk) 04:49, 15 January 2021 (UTC)[reply]

From World Wide Web#History, "While working at CERN, Berners-Lee became frustrated with the inefficiencies and difficulties posed by finding information stored on different computers." I believe this qualifies as a case of Necessity is the mother of invention. -- Tom N talk/contrib 05:12, 15 January 2021 (UTC)[reply]

Sometimes the question is asked, why did it take a physicist to come up with something that useful? Why was it not a computer scientist? If one takes a look at the funding ratio between fundamental physics research and academic research in software technology (not counting work on supercomputers and high-performance computing, which mostly serves physics purposes), it is not so amazing. A proposal similar to TBL's proposal, submitted in 1990, would almost certainly not have been awarded by agencies funding computer-science research – if only because most proposals, also good ones, could not be funded. --Lambiam 11:36, 15 January 2021 (UTC)[reply]

As is always the case, the "Great Man" theory falls short in explaining what, in reality, is incremental progress made by many people. Berners-Lee did come up with the World Wide Web while at CERN, but he did not come up with the entire field of computer networking on his own, nor did he even invent the internet. The basic pieces were there in other forms, he put it all together. Prior to the WWW, there were other means of sharing information such as FTP (which had been around since the 1970s). Hypertext had been around in theoretical form since the 1940s, and in practical form since the 1960s. To piggyback on Lambiam's point regarding funding sources and the slow way computer science developed, there was an alternate protocol to the WWW that was developed by computer scientists at around the same time, called Gopher (protocol). It was used in parallel to the WWW for much of the early years, I can remember using it during the early 1990s in college when the only web browser was NCSA Mosaic. Gopher was faster to implement than the WWW, but was far less functional. So it was adopted earlier even though it was technically developed after the the Web, but by the late 1990s, the Web had been developed to a point where Gopher looked laughably quaint. --Jayron 32 13:29, 15 January 2021 (UTC)[reply]

This is Lynx erasure! :p --47.152.93.24 (talk) 03:59, 17 January 2021 (UTC)[reply]

Tim wanted it to be easier to share scientific papers. This sounds insane to younger people, but you used to have to spend hours flipping through bundles of dead trees to find stuff. Now basically all phyics papers are pre-published on arXiv, and other fields are getting in on the practice. --47.152.93.24 (talk) 03:59, 17 January 2021 (UTC)[reply]

Where can I find current progress of open physics questions?

Where can I find current progress of open physics questions? Rizosome (talk) 05:19, 15 January 2021 (UTC)[reply]

Such as what? ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:50, 15 January 2021 (UTC)[reply]

Like this Rizosome (talk) 05:59, 15 January 2021 (UTC)[reply]

Try here: List of unsolved problems in physics. 41.165.67.114 (talk) 07:09, 15 January 2021 (UTC)[reply]

... and down the rabbit hole. 41.165.67.114 (talk) 07:13, 15 January 2021 (UTC)[reply]

I am asking about progress not the list. Rizosome (talk) 10:22, 15 January 2021 (UTC)[reply]

There are several websites that are dedicated to bringing science news, such as ScienceDaily and Live Science. If you monitor these regularly, say weekly, you will be kept abreast of all significant developments. In the former, though, physics news is subdivided into many categories and going through all of these one by one is tedious, while the physics news in the latter is almost all space-related. Science World Report has a generic consolidated physics section. --Lambiam 11:08, 15 January 2021 (UTC)[reply]

One of the top science journals, Nature, allows people (who do not need to be subscribers) to sign up to e-mail alerts. They will cover all sorts of topics but are very high quality summaries. "see here for sign-up details and examples".. Mike Turnbull (talk) 13:28, 15 January 2021 (UTC)[reply]

January 16

Chest x-rays

Are chest x-rays part of routine physical checkups in the US? Wondering due to this whether unusual amounts of them are showing damaged lungs, and if this is likely to be published somewhere. tx. 2601:648:8202:96B0:0:0:0:313A (talk) 01:02, 16 January 2021 (UTC)[reply]

Our article Physical examination#Comprehensive claims it may be part of a more comprehensive or "executive" physical examination although lacks a proper source. (It has one source which establish an initials can is taken as part of one executive physical, with followups only in certain situations, hopefully informed by science [12] [13].)

These sources suggest it was more common in the past particularly the 1960s to 1980s [14] [15] [16] [17], and apparently may still be demanded by some patients [18] (although that's fairly old by now and perhaps those who are used to routine chest x-rays are fewer). From what I can tell, although TB was more prevalent in the US then and testing options more limited, but there's still great question over their utility/wisdom.

I found another executive physical which does seem to use them routinely although I think only from 40 years [19], and only every 2 years not annually. I'm not sure how common such fancy physicals are, this [20] mentions 22% of Fortune 500 companies offer them to their CEOs which actually doesn't sound that many when you think about it. But this doesn't really tell us how common they are for smaller companies and for other positions, or paid for personally or by insurance. And that is talking about CT scans of the heart or even the full body so people may still get slightly more "comprehensive" physical examinations which do include chest x-rays but aren't so extreme.

Per one of the earlier sources and others [21] [22] [23], it also seems that routine or almost routine (i.e. without a real reason why it may be useful) chest x-rays on hospital admission or pre-surgery may still be hardly uncommon although the only sources [24] [25] I could find discussing frequency were from outside the US. (But I didn't look that carefully.)

Nil Einne (talk) 13:16, 16 January 2021 (UTC)[reply]

How many OPEN questions Spitzer Space Telescope did solve?

I want to know how many Open unsolved physics questions Spitzer Space Telescope did solve? Rizosome (talk) 16:03, 16 January 2021 (UTC)[reply]

By definition, "open" question and "unsolved" question mean the same: a question to which the answer is not (yet) known. The concept is too vague to quantify it. The telescope was designed to make observations, not to solve physics questions. It made many important observations that may help to increase our understanding of the universe, and did some surprising discoveries, as described in the article. --Lambiam 00:07, 17 January 2021 (UTC)[reply]

In fact, the observation, made by the Spitzer Space Telescope, that most older stars in the Galaxy are concentrated in two of the arms, has raised a new unsolved question: Why is this so? Why are the older stars not equally distributed over all arms? A deeper understanding of the evolutionary dynamics of the Galaxy than we have today is needed to answer that question. --Lambiam 00:18, 17 January 2021 (UTC)[reply]

Lambiam what does "arms" mean in space telescope context? Rizosome (talk) 03:17, 17 January 2021 (UTC)[reply]

Those would be the spiral arms of this galaxy. --142.112.149.107 (talk) 03:54, 17 January 2021 (UTC)[reply]

Cupron cell

Can you help creating a section or article about the Cupron-cell? This battery type has an air recharging option what made it popular around 1910 - also can be base of modern constructions. I found references (below). This thing yet mentioned neither in the Template:Galvanic_cells nor galvanic cell. My English not good enough to reach the needed quality level of articles. There is a Hungarian article hu:Cupron-elem from 2007 too.

--Rodrigo (talk) 21:14, 16 January 2021 (UTC)[reply]

This does not seem to be notable. Ruslik_Zero 20:12, 17 January 2021 (UTC)[reply]

January 17

Why NASA still running Hubble space telescope ?

Why NASA still running Hubble space telescope ? It is one of the longest serving telescope in space. Rizosome (talk) 03:01, 17 January 2021 (UTC)[reply]

They are still running it because it hasn't completely broken yet. And we haven't managed to get a better one into space yet. The James Webb Space Telescope was supposed to launch in 2007 and is currently scheduled to launch Oct 2021. Rmhermen (talk) 05:20, 17 January 2021 (UTC)[reply]

Scientific satellites and space probes are very expensive to design, build and launch (and repair while in orbit), but once launched relatively cheap to operate. So it makes sense to keep them running for as long as they can produce useful science. Having two telescopes is better than having one, as you can observe more objects. And although JWST is sometimes called the successor of HST, it isn't better in every respect. In particular, JWST isn't designed to work in blue or near-UV light. PiusImpavidus (talk) 11:45, 17 January 2021 (UTC)[reply]

Yes, scientists are bored with normal light. No upcoming space telescopes have visible light cameras. Rmhermen (talk) 22:42, 17 January 2021 (UTC)[reply]

Depends what you mean by upcoming. According to the above linked article on the Hubble space telescope, the Large Ultraviolet Optical Infrared Surveyor would have although it still more of a concept than a concrete plan and that article gives a 2025-2035 time frame. The article on the LUVOIR gives a 2039 launch window assuming it actually gets funded, but does confirm visible coverage is still planned. Note that both the Hubble and James Webb article mention that the James Webb does actually cover a small part of what is the human visible spectrum since it goes down to 600nm i.e. orange. Nil Einne (talk) 07:04, 18 January 2021 (UTC)[reply]

A potentially more likely example may be the Xuntian. As with a lot of Chinese stuff, it's difficult to get a read of what's going on, but AFAICT, it's still in active development [26] [27] [28] and it looks like it will include visible light imaging capabilities [29]. Development will likely depend on the Chinese large modular space station it's intended to be sometimes coupled to and serviced by, but I think it's clear China considers developing a successful space programme probably including a space telescope an important part of demonstrating their rise as a technological super power so it's fairly likely they will launch something, and they also likely have the resources to devote to it [30]. While this doesn't have to include visible light imaging, they'd likely want something capable of producing impressive images whatever those images are based on (as is the case most impressive images from space telescopes aren't based solely, maybe not even at all, on visible light). Nil Einne (talk) 10:17, 18 January 2021 (UTC)[reply]

January 18

Why do heart patients feel numbness in left arm?

Why do heart paitents feel numbness in left arm? Why specifically left arm ?Rizosome (talk) 02:01, 18 January 2021 (UTC)[reply]

As noted in Myocardial infarction, pain can be felt in various places, including the right arm as well as the left. ←Baseball Bugs ^{What's up, Doc?} carrots→ 08:18, 18 January 2021 (UTC)[reply]

See Referred pain as well. MarnetteD|Talk 02:12, 19 January 2021 (UTC)[reply]

The heart is on the left, and the arrangement of the blood vessels coming off of the aorta sends blood more forcefully to the left arm than the right. I recall hearing that it is thought that disturbances in the blood flow caused by the heart laboring prior to, during and after an infarction manifest more on the left due to this positioning of the left subclavian artery. Abductive (reasoning) 11:04, 19 January 2021 (UTC)[reply]

Sydney Harbour Bridge

Are the names of the steel makers stamped on to the girders? Jacquesviii (talk) 13:50, 18 January 2021 (UTC)[reply]

I have never heard of that being the case. There appears to be no mention of it in our Sydney Harbour Bridge article. Why would they be? Is this a convention among bridge builders? HiLo48 (talk) 02:05, 19 January 2021 (UTC)[reply]

When you say "steel makers", do you mean the guys who manufactured the structural steel used in the bridge? Or maybe just the company name, such as U.S. Steel? ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:17, 19 January 2021 (UTC)[reply]

Yes. The bridge was prefabricated by DORMAN LONG in Middlesbrough ENGLAND before being shipped to Sydney. I have seen many examples of DORMAN Long girders and beams that were stamped with that name but am curious to know if that happened to the Sydney Harbour Bridge steelwork. Thanks.82.34.222.35 (talk) 09:50, 19 January 2021 (UTC)[reply]

It seems the answer is "yes". Abductive (reasoning) 11:27, 19 January 2021 (UTC)[reply]

I distinctly remember seeing the name on the bridge when I visited decades ago, as it gave rise to a prolonged piss-take of our Australian hosts, who had previously been outspoken on the supposed inferiority of British weather, food, beer, cricket etc. etc. However, I have failed miserably to find a photograph. Alansplodge (talk) 14:25, 19 January 2021 (UTC)[reply]

The Sydney Harbour Bridge is truly magnificent. Climbing it and seeing 'Dorman-Long Middlesbrough' stamped on the girders made me proud - and furious at the same time. It is incomprehensible that Teesside has failed to let the world know that it originated on Teesside. 82.34.222.35 (talk) 23:51, 19 January 2021 (UTC)[reply]

Diary of Portuguese traveller from 1506.

I'm trying to find out about the earliest record of European contact with chimpanzees, and one of the pieces of information I keep finding, is that "The diary of Portuguese explorer Duarte Pacheco Pereira (1506), preserved in the Portuguese National Archive, is probably the first European document to acknowledge that chimpanzees built their own rudimentary tools." And everywhere I look I just keep finding that same sentence, probably originally from Wikipedia, without giving any source. Is there anywhere that would provide an actual source, or an extract of the diary that explains this comment, because it seems a fairly remarkable claim, given that this is what Jane Goodall became known for over 400 years later. Thanks.

Probably refers to the Esmeraldo de Situ Orbis. Abductive (reasoning) 11:14, 19 January 2021 (UTC)[reply]

Having nothing better to do, I scanned through an English translation of Esmeraldo, but the only possible description of an ape is in Chapter 33 which is about Sierra Leone and where Pereira says:

"Here, as well, are wild men whom the Ancients called satyrs. They are covered with hairs almost as coarse as the bristles of a pig; they seem human and lie with their wives after our fashion, but instead of speaking they shout when they are hurt. As they dwell in the fastnesses of this Serra they can rarely be captured except when very young. I omit many other things concerning them in order to avoid prolixity".

The editor has a footnote saying that this has been taken as referring to gorillas, however these are not found in Sierra Leone. Alansplodge (talk) 14:05, 19 January 2021 (UTC)[reply]

(ec) The supposed reference to chimpanzees is almost certainly to this brief passage, translated by George H. T. Kimble as: Here, as well, are wild men, whom the ancients called satyrs. They are covered with hairs almost as coarse as the bristles of a pig; they seem human and lie with their wives after our fashion, but instead of speaking they shout when they are hurt. As they dwell in the fastnesses of this Serra they can rarely be captured except when very young. Most scholars of the text have interpreted these "wild men" covered with coarse hair, incapable of speech, as being chimpanzees. There is no mention of the use or making of tools, though; someone must have made that up, or must have misinterpreted what someone else wrote, after which this kept being copied. --Lambiam 14:11, 19 January 2021 (UTC)[reply]

Yes, its a bit suspicious that nearly every reference starts with an identical formula: "The diary of Portuguese explorer Duarte Pacheco Pereira (1506)..." Alansplodge (talk) 14:19, 19 January 2021 (UTC)[reply]

I've added a ^{[dubious – discuss]} tag to the claim in our Duarte Pacheco Pereira article. Alansplodge (talk) 16:20, 19 January 2021 (UTC)[reply]

You may also be interested in Man's Place in Nature (1863) by Thomas Henry Huxley, which discusses the early descriptions of apes in Chapter I: ON THE NATURAL HISTORY OF THE MAN-LIKE APES. Alansplodge (talk) 14:50, 19 January 2021 (UTC)[reply]

What laying position is more likely to cause nocturnal emission, prone or supine positions?

What laying position is more likely to cause nocturnal emission, prone or supine positions? I'm looking for scientific references for it. (n.b. I know there are different causes, but I'm asking specifically about the influence of those 2 sleeping positions) --ThePupil (talk) 22:17, 18 January 2021 (UTC)[reply]

Neither is more likely to cause it, because it's caused by other factors entirely.

The bulk of ejaculate comprises seminal fluid, which is produced by the seminal vesicles fairly continuously to replenish what may be ejaculated via intercourse or masturbation. If the latter occur sufficiently infrequently that the vesicles reach their capacity, a nocturnal emission will occur (in a healthy individual) regardless of sleeping position.

All humans necessarily dream, usually several times per night (though dreams are usually remembered only if the individual wakes during or shortly after dreaming), and in healthy males this is usually accompanied by penile erection regardless of the dream content (which is only sexual about 10% of the time).

Not surprisingly, nocturnal emissions usually (though not invariably) occur during penile erection and hence dreaming, and the associated sensations may influence the subject matter of the dream (with sexual or urinatory images), and may also induce the sleeping dreamer to adopt a posture reinforcing the sensations, which may more often be prone since this places pressure on the penis – however, the position is at most a result of the process, not its cause. {The poster formerly known as 87.81.230.195} 90.200.40.9 (talk) 01:12, 20 January 2021 (UTC)[reply]

January 19

substitution reactions of alcohols with halides to form alkyl halides

Someone told me that in the substitution reactions of alcohols with halides to form alkyl halides, tertiary alcohols react faster than secondary alcohols and primary alcohols. Why is that so?Jocosus2000 (talk) 08:12, 19 January 2021 (UTC)[reply]

That transformation goes by a mechanism called SN1 reaction in which the intermediate is a carbocation. The stability of these cations goes in the sequence primary<secondary<tertiary, hence the fastest example is where that cation is tertiary. Note that in practice the reaction needs very strong acid and possibly a dehydrating agent to remove the water that is formed from the alcohol. Otherwise it can go in the reverse direction (i.e. alcohols can be made from alkyl halides, as the SN1 reaction article describes). Mike Turnbull (talk) 11:36, 19 January 2021 (UTC)[reply]

Thanks, will there be SN2 reaction? If there is SN2 reaction then primary alcohols will be faster...Jocosus2000 (talk) 11:55, 19 January 2021 (UTC)[reply]

SN2 reactions are almost always used when starting with alkyl halides and going to something else. Alcohols themselves don't react in SN2 reactions unless first transformed into a good leaving group (e.g. tosylate). But you are correct that for SN2 reactions the rate of reaction is usually primary>secondary, with tertiary essentially unreactive by that mechanism. Any decent organic chemistry textbook will expand on this if the Wikipedia articles aren't enough. Mike Turnbull (talk) 13:55, 19 January 2021 (UTC)[reply]

Okay. thank you so much!Jocosus2000 (talk) 00:19, 20 January 2021 (UTC)[reply]

What makes General relativity is different from Quantum mechanics?

What makes General relativity is different from Quantum mechanics? Rizosome (talk) 14:25, 19 January 2021 (UTC)[reply]

Wow. That's a BIG QUESTION. The best way I can answer it is thusly: Modern quantum mechanics is fundamentally about quantized fields, see Quantum field theory for the gory details, but in VERY SIMPLIFIED version, a quantum field is a field that is quantized. I know that's not much help, so here's what each of THOSE means: a field is a value which is assigned to every point in space. That value can be a simple one-part number (called a scalar), a two-part number called a vector, or a multi-part number called a tensor; but regardless of which it is, you just need to think about the field as simply a value assigned to every point in space. For example, an electric field is a set of values assigned to every point in space telling you how a point charge will move if it were located at that spot. A field is quantized if the values assigned to that spot have a functional minimum size called the quantum of that property. Values of the field cannot be smaller than that quantum value, and all values need to be a multiple of that quantum value (i.e. no "in-between values"). General relativity states that gravity is not caused by a force, but rather by curved spacetime. The fundamental problem is that each theory contains an axiom which makes it incompatible with the other theory, and that attempts to take that axiom out breaks the theory in question. For example, quantum mechanics assumes a flat, continuous spacetime; space and time are not quantized per se, it's the values that are assigned to the fields in space that are quantized; space itself in QM is continuous and flat. In order to have quantum gravity, you'd have to have quantized spacetime itself; i.e. some fundamental unit of spacetime which cannot be further subdivided. That introduces all sorts of paradoxes into both theories. I've probably oversimplified and glossed over some stuff here, but Here is a video from PBS Space Time which is at what I would call a "High Layperson" level (some background vocabulary knowledge and exposure to the basics of these theories needed, but no math involved). If you want some good "low level" coverage of modern physics (for the real layperson, with no background) the BEST stuff can be found at The Science Asylum, whose explanations are fantastic even for people with no background in the subject. He has a NUMBER of great videos on both General Relativity and Quantum Theory. His videos on Quantum Fields, for example, would be a great overview for what I tried to explain above. --Jayron 32 17:01, 19 January 2021 (UTC)[reply]

A very big difference is that GR is a classical theory, where you can predict the evolution of a system by solving some differential equations, like in Newtonian mechanics except the equations are more complicated. QM is different because measurement outcomes are probabilistic. No one understands what is really going on "underneath", and explaining it is called the (unsolved) measurement problem. 2601:648:8202:96B0:0:0:0:313A (talk) 22:01, 19 January 2021 (UTC)[reply]

Who won Thorne–Hawking–Preskill bet at the end?

Who won Thorne–Hawking–Preskill bet at the end? Wiki article didn't mention any winners clearly. Rizosome (talk) 16:38, 19 January 2021 (UTC)[reply]

It hasn't been resolved yet. The black hole information paradox has not been fully resolved in a way that would satisfy the terms of the bet. Some recent developments were published in 2019 that the Wikipedia article oversells a bit; the significance of these new developments have not been fully explored, and even if they resolve some of the issues, they do not resolve all of them. --Jayron 32 17:05, 19 January 2021 (UTC)[reply]

@@ Line 284: / Line 284: @@
 :Neither is more likely to cause it, because it's caused by other factors entirely.
 :The bulk of [[ejaculate]] comprises [[seminal fluid]], which is produced by the [[seminal vesicles]] fairly continuously to replenish what may be ejaculated via intercourse or masturbation. If the latter occur sufficiently infrequently that the vesicles reach their capacity, a nocturnal emission ''will'' occur (in a healthy individual) regardless of sleeping position.
-:All humans necessarily [[dream]], usually [[Rapid eye movement sleep|several times per night]] (though dreams are usually remembered only if the individual wakes during or shortly after dreaming), and in healthy males this is [[Rapid eye movement sleep#Circulation, respiration, and thermoregulation|usually accompanied by penile erection]] regardless of the dream content (which is only sexual about 10% of the time). Not surprisingly, nocturnal emissions usually (though not invariably) occur during penile erection and hence dreaming, and the associated sensations may influence the subject matter of the dream (with sexual or urinatory images), and may also induce the sleeping dreamer to adopt a posture reinforcing the sensations, which may more often be prone since this places pressure on the penis – however, the position is at most a result of the process, not its cause. {The poster formerly known as 87.81.230.195} [[Special:Contributions/90.200.40.9|90.200.40.9]] ([[User talk:90.200.40.9|talk]]) 01:12, 20 January 2021 (UTC)
+:All humans necessarily [[dream]], usually [[Rapid eye movement sleep|several times per night]] (though dreams are usually remembered only if the individual wakes during or shortly after dreaming), and in healthy males this is [[Rapid eye movement sleep#Circulation, respiration, and thermoregulation|usually accompanied by penile erection]] regardless of the dream content (which is only sexual about 10% of the time).
+:Not surprisingly, nocturnal emissions usually (though not invariably) occur during penile erection and hence dreaming, and the associated sensations may influence the subject matter of the dream (with sexual or urinatory images), and may also induce the sleeping dreamer to adopt a posture reinforcing the sensations, which may more often be prone since this places pressure on the penis – however, the position is at most a result of the process, not its cause. {The poster formerly known as 87.81.230.195} [[Special:Contributions/90.200.40.9|90.200.40.9]] ([[User talk:90.200.40.9|talk]]) 01:12, 20 January 2021 (UTC)
 = January 19 =