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April 12

Does Humulus lupulus leaf contain estrogen?

Is the estrogen of Hops in the leaf or in another part/s of the plant?

Thanks, 2A10:8012:19:AD67:9807:EAF6:E6B1:5A7B (talk) 21:38, 12 April 2023 (UTC)[reply]

Yes, and in strobili ("cones", i.e. hops). --136.56.52.157 (talk) 23:28, 12 April 2023 (UTC)[reply]
To clarify, hops are from the "cone" part of the plant (Humulus lupulus); and for example, the leaves of the plant itself are not used for making beer. The leaf-like structures of the strobili are referred to as decussation; which, if I understand correctly, relates to their being a "cross" between a stem and a leaf. All parts of the plant (AFAICT) contain 8-Prenylnaringenin, considered to be the most potent plant estrogen (estrogenic phytoestrogen). --136.56.52.157 (talk) 03:26, 13 April 2023 (UTC)[reply]

Sources
  • Milligan, S. R.; Kalita, J. C.; Heyerick, A.; Rong, H.; De Cooman, L.; De Keukeleire, D. (1 June 1999). "Identification of a Potent Phytoestrogen in Hops (Humulus lupulus L.) and Beer". The Journal of Clinical Endocrinology & Metabolism. 84 (6): 2249–2249. doi:10.1210/jcem.84.6.5887.
  • Chadwick, L.R.; Pauli, G.F.; Farnsworth, N.R. (January 2006). "The pharmacognosy of Humulus lupulus L. (hops) with an emphasis on estrogenic properties". Phytomedicine. 13 (1–2): 119–131. doi:10.1016/j.phymed.2004.07.006.
P.s.: I thoroughly messed up inline citations; two sources are above --136.56.52.157 (talk) 03:44, 13 April 2023 (UTC)[reply]

April 13

Scientific paper, hit rate AI assigns gender

Hello,
I am looking for a good scientific paper (or a book) that statistically analyzes the accuracy with which a trained neural network can assign gender based on brain scans.
(I just look out of curiosity.) 2A02:908:424:9D60:5D08:2AD7:1469:49BF (talk) 11:20, 13 April 2023 (UTC)[reply]

AI and gender. Yep that sounds like it would be a winner on Twitter ;-) I think they'd be wishing themselves an interesting life! NadVolum (talk) 11:35, 13 April 2023 (UTC)[reply]
Obviously the neural network would have to be trained to acknowledge the superiority of the female brain... MinorProphet (talk) 11:51, 13 April 2023 (UTC) [reply]
That may depend on the gender the AI self-assigns. -- Verbarson  talkedits 12:13, 13 April 2023 (UTC)[reply]

I asked a trained neural network that insisted that these are real studies that have investigated the neural correlates of gender identity:

Hahn, A., Kranz, G. S., Kublbock, M., Kaufmann, U., Ganger, S., Hummer, A., ... & Windischberger, C. (2015). Structural connectivity networks of transgender people. Cerebral Cortex, 25(10), 3527-3534. doi: 10.1093/cercor/bhu206

Joel, D., Berman, Z., Tavor, I., Wexler, N., Gaber, O., Stein, Y., ... & Assaf, Y. (2015). Sex beyond the genitalia: The human brain mosaic. Proceedings of the National Academy of Sciences, 112(50), 15468-15473. doi: 10.1073/pnas.1509654112

Kranz, G. S., Hahn, A., Kaufmann, U., Küblböck, M., Hummer, A., Ganger, S., ... & Windischberger, C. (2018). White matter microstructure in transsexuals and controls investigated by diffusion tensor imaging. Journal of Neuroscience, 38(44), 9589-9596. doi: 10.1523/JNEUROSCI.3342-17.2018

Manzouri, A. H., Savic, I., & Berglund, H. (2017). Nucleus accumbens and anterior cingulate cortex function and connectivity during visual erotic stimuli in heterosexual and homosexual men. Frontiers in Neurology, 8, 512. doi: 10.3389/fneur.2017.00512

Rule, N. O., & Ambady, N. (2008). Brief exposures: Male sexual orientation is accurately perceived at 50 ms. Journal of Experimental Social Psychology, 44(4), 1100-1105. doi: 10.1016/j.jesp.2008.02.002 Philvoids (talk) 14:22, 13 April 2023 (UTC)[reply]

Most of them do correspond to something real though bits do seem to be changed or made up. I'm impressed, it's a good response to start working from. Kind of what you'd get from an expert who didn't have their notes with them. NadVolum (talk) 11:25, 14 April 2023 (UTC)[reply]

April 14

water that has been lingering in the pipes

I'm in bottom floor of 4 story apt building. Landlord notified me that the water would be shut off for part of today for plumbing repairs, but I forgot about this, and needed 2 cups of water to make oatmeal. I turned on the kitchen faucet during the the shutoff period and water came out at about 1/4 of its usual speed, I guess draining from pipes in the building, but I was able to get my 2 cups and the oatmeal tasted fine.

Any idea if there are health hazards from this, such as metals in the water? Not worried about microbes in this instance since the water got thoroughly boiled for the oatmeal, but in other situations I guess those could be a concern too. Thanks. 2602:243:2007:9990:FC12:23ED:462:65F4 (talk) 00:32, 14 April 2023 (UTC)[reply]

It's highly unlikely to be a problem. For millennia people having been drinking water from water tanks and many other places where the water is stationary for quite long periods. HiLo48 (talk) 02:07, 14 April 2023 (UTC)[reply]
I'm puzzled as to why you think this could possibly be hazardous? Water is "lingering" in the pipes most of the time. It only flows when a faucet is opened. It's just as safe as water that has been lingering in a bottle. Shantavira|feed me 08:30, 14 April 2023 (UTC)[reply]
One reason is if there is lead in the plumbing. My house receives water from the main in the street through a pipe ("service line") about 30 feet (10 m) long, and it was a lead pipe from 1924 when the house was built until 2008 when it was replaced with copper. At some point the city advised people who had a lead service line that they should run the taps long enough to flush the standing water out of the pipe each morning before drinking any. I only heard about this when the pipe was about to be replaced. I had a blood test for lead then, but it was negative, so I don't imagine the risk in such a case is very serious. But is it possible? Looks like it. --174.89.12.187 (talk) 05:39, 15 April 2023 (UTC)[reply]
If you have hard water the take-up of lead is reduced, in part due to scaling on the inside of the pipes. Martin of Sheffield (talk) 11:00, 15 April 2023 (UTC)[reply]
One possible risk is if someone about you had a hose on a tap running into a bath or something like that. It may siphon dirty water back into the plumbing. But your boiling would most likely render it safe. Graeme Bartlett (talk) 22:55, 14 April 2023 (UTC)[reply]
Plumbing term for this is backflow. For this reason large water systems frequently are required to have backflow prevention devices where they connect to the "global" water system. --47.155.46.15 (talk) 02:28, 16 April 2023 (UTC)[reply]

Nuclear laptops

Why are there tritium powered exit signs, but not tritium powered laptops? Someone who's wrong on the internet (talk) 03:55, 14 April 2023 (UTC)[reply]

Who says there aren't? Obtain laptop and betavoltaic power sources. Connect these to the laptop power charge socket. This might require a little custom wiring. Voila, tritium-powered laptop. The neat thing about electric power is things that use it don't care what the source of the energy is, and thus you can use anything that provides the needed electrical power characteristics. Sun-powered car, sure why not?
A more comprehensive question in line with what you're probably thinking is, "Why don't people sell a lot of laptops with integrated betavoltaic sources", which is a question at the intersection of engineering and economics. Such laptops would be bulky in order to provide the necessary power—dimly lighting a sign takes a lot less power than a typical consumer computer. The overwhelming characteristics purchasers want in portable electronics are light weight and easy portability. The demand isn't there. And as covered, you can just connect the laptop to pretty much whatever you want, which then lets you connect/disconnect as desired. Power banks and portable generators and fuel cells are all available. (Modern ICE automobiles double as electrical generators with their automobile auxiliary power outlets. Electric vehicles often have them as well, though in an all-electric you're of course drawing down the vehicle batteries instead.) 47.155.46.15 (talk) 04:27, 14 April 2023 (UTC)[reply]
"Who says there aren't?" I'm willing to say it. There isn't such a device available for commercial sale, and nobody has ever chained together enough betavoltaic sources to power a consumer laptop. An efficient low-power laptop might draw as little as 20 watts. The total energy output from tritium decay is something like 0.3 watts per gram, so that's a minimum of 60+ grams of tritium (about 60,000 curies) to get 20 watts of heat. At $30,000 per gram, that's two million dollars worth of the stuff. And that's making the - totally unrealistic - assumption of perfect conversion to electrical energy. (In real betavoltaic devices, I think the figure is less than 1%.) TenOfAllTrades(talk) 13:40, 15 April 2023 (UTC)[reply]
Right, that's a part of what makes it economically unfavorable. Though, you could charge a battery with beta sources. Even if the lithium-ion batteries in modern laptops are finicky about their charging input, you can always wire up a different battery type that's easy to trickle charge. --47.155.46.15 (talk) 02:25, 16 April 2023 (UTC)[reply]

Cenozoic dinosaurs

Are there surviving non-avian dinosaurs from the Paleocene? I have heard of trodons, hadrosaurs, surviving microraptors or even small oviraptors that lived long after K-T. BristiBoop78786778 (talk) 07:25, 14 April 2023 (UTC)[reply]

Wikipedia has an article about dinosaurs. The first paragraph says that all non-avian dinosaurs are extinct. Shantavira|feed me 08:24, 14 April 2023 (UTC)[reply]
That's what they want you to think. —Tamfang (talk) 18:51, 16 April 2023 (UTC)[reply]
More specifically you can read Dinosaur#Possible_Paleocene_survivors. Ruslik_Zero 12:22, 14 April 2023 (UTC)[reply]

https://timesofindia.indiatimes.com/india/just-mind-games-indian-mentalists-are-busting-the-chamatkar-myth/articleshow/98052200.cms

I have seen some videos on news channels. They touch somebody's hands, they ask them to mention some number and they give personal details which they are not supposed to know. Sometimes they even read thoughts.

Are these staged? Mean the girl among the audience knew the mentalist and she was trained to fool the audience. They are telling this as some art, but they are demonstrated as some supernatural power like telekinesis.


I also want to know about these tarot card readers that appear so many time in Hollywood movies. Do Americans visit tarot card readers? Arjun Singh 2004 (talk) 09:57, 14 April 2023 (UTC)[reply]

You linked the word Mentalism in the section title here. Did you read that article? HiLo48 (talk) 10:40, 14 April 2023 (UTC)[reply]
Probably not "staged" in the sense of a shill (stooge). It could also be a case of hot reading which might qualify as "staged" depending on your definition. However, without having looked at the article or video, your description does not seem impossible to achieve by means of cold reading.
In the case of videos, editing also comes into place: in the words of Penn and Teller, if I show you a video of someone picking a card and the magician immediately telling which card it is, that’s impressive, but if I tell you the magician stood for two hours in the street and the camera operator made about fifty takes, less so. TigraanClick here for my talk page ("private" contact) 12:53, 14 April 2023 (UTC)[reply]
Probably the words of Penn … —Tamfang (talk) 18:53, 16 April 2023 (UTC)[reply]

Has English subtitle- https://www.youtube.com/watch?v=TEZoVK33TZU — Preceding unsigned comment added by Arjun Singh 2004 (talkcontribs) 13:45, 14 April 2023 (UTC)[reply]

Yes, I see nothing there that can't easily be explained by the explanations already provided above 1) The person being so interviewed was a "shill" or a "plant" (they were a rehearsed part of the act) 2) The stage performer had prior knowledge of the audience member (she had filled out a survey of some sort, not knowing what it was for, for example) or most likely 3) The stage performer is well-trained in the techniques of Cold reading. Most of the time, this is how they do their tricks. It could also be 4) Cherry picking a specific time that he got it right from among many performances, and only putting that one on the internet for you to watch. Less likely than a good cold reading. --Jayron32 15:46, 14 April 2023 (UTC)[reply]
In the 20th-Century Western Mentalism and Spiritualism 'industry', many believing customers would attend as many shows and/or seances as possible. Long before the computer age there was an organisation to which the performers would send data about their clients, garnered during or before seances and at theatre performances (by mingling in the foyer, etc.). This was compiled on file cards, and if one or more regular participators were identified as being in the audience of a show, the Mentalist's assistants could phone the organisation and be given all the facts known about them. Sorry for no reference, I've been interested in such subjects for half a century and have long known this.
Obviously, modern comms and computing would make this even easier than before. {The poster formerly known as 87.81.230.195} 90.213.18.208 (talk) 19:13, 14 April 2023 (UTC)[reply]
See also cold reading and hot reading for details of the techniques. For an actual example, see Doris_Stokes, a famous British medium who died in 1987 shortly before her audience planting techniques were revealed. Alansplodge (talk) 13:04, 18 April 2023 (UTC)[reply]
Died at age 67. I wonder if she saw that coming. ←Baseball Bugs What's up, Doc? carrots14:58, 18 April 2023 (UTC)[reply]
Her business was permanently closed due to unforeseen circumstances. -- Jack of Oz [pleasantries] 23:04, 18 April 2023 (UTC) [reply]

April 15

A river, a tributary, a peninsula, and a flood

I think this is a hydrology question? The picture shows the junction of a the Kern River and one of its tributary creeks in the Sierra Nevada in central California. The flow is north to south. The river and the creek run almost parallel for a while, and are separated by a peninsula which comes to a point at the junction of the creek and the river. When the flow of the river is sufficient, the peninsula is mostly submerged and the creek meets the river a ways upstream. The peninsula ends where I've marked the picture in black. Or, at least, it used to. During March's atmospheric river-caused floods, both the Kern and the creek got huge; the combined flow of the river and the creek was briefly 45,000 cubic feet per second (highest flow in 60 years), compared to about 700cfs the day before. When the water receded, to my surprise the peninsula had grown downstream about 100 feet, as marked in the picture in red. The new growth is indistinguishable from the rest of the peninsula, other than that nothing has tried to grow there yet. Sand and rocks. My question is: what's happening here? What makes a peninsula grow like this? --jpgordon𝄢𝄆𝄐𝄇 01:17, 15 April 2023 (UTC)[reply]

Chances are it's sediment that was deposited during the flooding events. A great deal of erosion would have occurred upstream and the rivers would have been flowing more quickly during the flooding events, resulting in higher sediment loading. The area just downstream from the tip of the peninsula would not have experienced as high of speeds as areas upstream, so insufficient mechanical energy would have been present there to prevent sediment deposition, resulting in the extension of the sand bar. As a general rule, streams have steeper gradients near their headwaters and erode more sediment than they deposit, while the reverse is true near the mouth. A gradient of sorts exists along the length of the stream: more erosion and higher speeds near the source, and more deposition and slower speeds near the mouth. This is why small tributary streams often have large boulders and cobbles along their banks (which require higher water velocities and more energy to stay entrained, and the lower reaches and deltas of rivers are characterized by fine-grained silt. Deltas are formed when the water from a stream slows as it enters a lake or ocean, and drops all of its sediment because the forward motion of the water is no longer sufficient to keep it entrained. The water where deltas are formed generally has lower velocities than any other part of the stream, so the finest-grained sediment is usually found in deltas. This phenomenon can also be observed on smaller scales: the bottom of the main channel of a large, fast-moving river will often contain large rocks up to around 20 centimetres (7.9 in) in diameter, the beds of slower side channels might be sandy. This is the case for a lot of rivers I've seen in the Cascade Mountains of Washington, for example. — SamX [talk · contribs · he/him] 01:48, 15 April 2023 (UTC)[reply]
The speed drop at the deposition zone makes sense. Thanks! Good explainer. --jpgordon𝄢𝄆𝄐𝄇 05:32, 15 April 2023 (UTC)[reply]
Essentially this is a kind of bar (river morphology). These can form at a confluence when there is a difference between the merging watercourses in speed, sediment load, or other factors, as SamX has discussed. Eventually under the right conditions they can grow into a river island. This image of the confluence of the Blue and White Nile in Khartoum is a nice example. I presume that small island got gradually built up there from these processes. --47.155.46.15 (talk) 01:57, 16 April 2023 (UTC)[reply]


April 16

Opposition to the idea of autogynephilia

We don't answer requests for opinions, predictions, or debate. --47.155.46.15 (talk) 02:19, 16 April 2023 (UTC)[reply]
The following discussion has been closed. Please do not modify it.

Is there a particular reason that trans women in particular are so adamantly against the existence of autogynephilia as an actual condition? I was reading around and noticed that some of the most prominent and vocal critics of the concept are themselves trans women and thought it was interesting and possibly worth exploring. Thanks! ZoxxoZ (talk) 14:12, 15 April 2023 (UTC)[reply]

The autogynephilia article addresses this. --jpgordon𝄢𝄆𝄐𝄇 14:34, 15 April 2023 (UTC)[reply]
That some particular trans women are against the idea does not mean that trans women in general are; you may be experiencing a form of confirmation bias. That said, people who are trans women may have a better informed opinion on the matter than people who aren't, and/or some may incorrectly generalise their personal experience over-widely to what is doubtless a complex mix of differing instances. {The poster formerly known as 87.81.230.195} 90.213.18.208 (talk) 14:44, 15 April 2023 (UTC)[reply]

It seems to me a rational explanation might be that trans women are emotionally invested in the subject and resistant to the idea that their trans identity is in fact a paraphilia which they themselves find embarrassing. It makes sense that one would seek out an explanation for oneself that puts oneself in the best light, while rejecting those that they perceive as distasteful. Effectively denial, of sorts. A very effective and coordinated denial, but a denial nonetheless. ZoxxoZ (talk) 15:15, 15 April 2023 (UTC)[reply]

On what do you base the assertion that this is a coordinated denial? And why did you write, "but a denial nonetheless"? Perhaps the critics are right and this autogynephilia condition is just as bogus as the hysteria condition, in vogue as a medical diagnosis in the 19th century. The owner of Comet Ping Pong called the Pizzagate conspiracy theory "an insanely complicated, made-up, fictional lie-based story". Would you refer to this statement as "a forceful denial, but a denial nonetheless"?  --Lambiam 19:33, 15 April 2023 (UTC)[reply]
This is clearly asking for opinion and speculation. --jpgordon𝄢𝄆𝄐𝄇 19:42, 15 April 2023 (UTC)[reply]
"A very effective and coordinated denial..." That's absurd. HiLo48 (talk) 22:48, 15 April 2023 (UTC)[reply]

The “effective and coordinated” part refers to having a movement to convince enough of society that gender identity is not a paraphilia. Basically, through activism to bludgeon unquestioning acceptance and denial of reality into the mainstream, and sustained to the point where one is labeled a hateful bigot for even questioning the nature of gender identity. It’s a manner of non-debate, wherein rather than refuting a theory through reasoned debate, the theory is discredited by simply applying a pejorative label. For what it’s worth, this response is understandable and well-documented in the context of denial held by large populations. ZoxxoZ (talk) 03:24, 16 April 2023 (UTC)[reply]

Maybe you could increase your credibility by telling us more about the alleged "coordination" you see. HiLo48 (talk) 03:46, 16 April 2023 (UTC)[reply]

April 17

Laptop charger's 3rd prong broke off.

My laptop has 3 prongs and the 3rd 1 got cut and fell out. My laptop still recharges fine. Are there long-term disadvantages? My previous laptop has 2-prongs, why do some have 3? This appliance happens to be a laptop but I see it more of a science question. Thanks. 67.173.182.93 (talk) 11:51, 17 April 2023 (UTC).[reply]

The "third prong" I am guessing is the ground or earth wire, and you should not continue to use the plug. It will still operate, but the ground wire is an important safety feature that protects both you and your device. See here. I'm sure you can order a replacement charger, and should probably do so. --Jayron32 12:10, 17 April 2023 (UTC)[reply]
Are you referring to the cable from the wall socket to the charger, or the cable from the charger to the laptop? If the former, Jayron32 has already answered, do not use it and get a replacement. If the latter it may be some form of communication between the laptop and the charger. Some manufacturers restrict non-proprietary chargers to a slower charge rate or not at all. Martin of Sheffield (talk) 13:24, 17 April 2023 (UTC)[reply]
I'd guess the earth prong was made of plastic, and it's purpose was to open the other slots. In which case be careful notr to touch the other prongs whilst plugging in the charger and you won't be able to use he charger with other plugs. You might have to use something like superglue to remove the prong from the socket. Don't stick in anything metal! NadVolum (talk) 16:06, 18 April 2023 (UTC)[reply]
I suppose the charger has the form of a little plastic box that sits directly over an outlet (a wall wart), with a low-voltage cord coming from it to reach the laptop. If so, then there is no real need for it to be grounded and it may have been built with a grounding (3-prong) plug because someone thought that was the correct standard to adhere to. However, if you have British-type electrical outlets then NadVolum's concern about "opening the other slots" would apply. --174.89.12.187 (talk) 22:04, 18 April 2023 (UTC)[reply]

Sorry for late reply, but yes I would say is the latter to Martin's question. Cable to laptop. But maybe I can extend this question to a simpler appliance in general, a 2-prong lamp vs. 3-prong lamp? What would the differences be? Thanks. 67.173.182.93 (talk) 02:07, 19 April 2023 (UTC).[reply]

If the lamp has metal parts that you can touch, they should be grounded to prevent a shock in case the wiring inside gets damaged. --174.89.12.187 (talk) 06:45, 19 April 2023 (UTC)[reply]
As explained already above in the first reply, the third prong provides grounding; see here.  --Lambiam 06:58, 19 April 2023 (UTC)[reply]
Then how do laptops and appliances with only 2-prongs, do grounding? 67.173.182.93 (talk) 12:17, 19 April 2023 (UTC).[reply]
The simple answer is that they don't. Have a look at Appliance classes, in particular class II. In essence, if there is a possibility of exposed metalwork becoming live then the appliance has to be earthed (except in the USA). If there is no possibility of accessible parts becoming live, then it will be class II ("double insulated") and doesn't need earthing. If the item is totally isolated from the mains, such as a laptop, then it is class III and no safety earthing is required. Martin of Sheffield (talk) 13:47, 19 April 2023 (UTC)[reply]

Thoughtful non-blinking posture

Is there a name for condition when healthy people sometimes freeze for a few seconds in a thoughtful position, with their eyes not blinking and fixed at a random point? I suspect it's relatively common. 212.180.235.46 (talk) 18:06, 17 April 2023 (UTC)[reply]

Reflective pose? --136.56.52.157 (talk) 20:41, 17 April 2023 (UTC)[reply]
AFAIK reflective pose may involve facial changes and some other gestures. The one I'm interested has no movements at all, eyes not blinking and "frozen" as well, and typically occurs while sitting (this has been experienced by me and observed in other persons too). Possibly has something to do with relaxation. 212.180.235.46 (talk) 21:37, 17 April 2023 (UTC)[reply]
"in vacant or in pensive mood..." or "lost in thought"? Alansplodge (talk) 23:19, 17 April 2023 (UTC)[reply]
A different condition resembling this one is called here the "freeze response". This withdrawal freeze typically lasts much longer than this pensive freeze. The latter may serve to allow more mental processing resources to be devoted to producing a result. It is (at least according to my observations) mainly seen in a dialogue, when a respondent is trying to remember something or to find a good way to explain something. They may also grab their chin, but why?  --Lambiam 09:13, 18 April 2023 (UTC)[reply]
Consider "petit mal" seizure or Catatonia syndrome. Philvoids (talk) 10:56, 18 April 2023 (UTC)[reply]
See also the thousand-yard stare, a symptom of battle fatigue. We also have an article called Blank expression. Alansplodge (talk) 12:57, 18 April 2023 (UTC)[reply]
Another possibility: White line fever. (WP:OR: had a couple of personal experiences with this phenomenon driving while sleep-deprived, and I can personally attest that a fixed stare is indeed one of the main symptoms of it!) 2601:646:9882:46E0:B06E:637E:D483:879D (talk) 02:58, 19 April 2023 (UTC)[reply]
I think petit mal, catatonia, the thousand-yard stare and white line fever all have nothing to do with the condition referred to in the OP, which may occur in the middle of the day to someone relaxed, awake and well, comfortably seated on a couch.  --Lambiam 07:08, 19 April 2023 (UTC)[reply]

April 18

"Закрой сифон и поддувало"?

I wanted to ask this for the past few weeks: according to my mother, when she was a child (back when many trains in Russia still used steam traction), one would sometimes see trackside signs saying "Закрой сифон и поддувало" ("Close blower and damper"), or maybe "Открой сифон и поддувало" ("Open blower and damper"), but she did not remember anything more about this (other than the fact that she and her friends got a good laugh out of these signs). So, several questions: (1) Am I right that "сифон" = blower and "поддувало" = damper? (2) Is it "open" or "close" blower and damper? (3) Where exactly would these signs be found (my guess is these would be found before tunnels, to reduce the amount of smoke in tunnels and/or to prevent dangerous blowbacks from the firebox -- is that correct)? 2601:646:9882:46E0:B0D1:2E92:F1FD:9C73 (talk) 01:41, 18 April 2023 (UTC)[reply]

As to question 2, the obvious thing would be to see "close" at the start of a zone where they should be closed, and "open" at the end of it. It's like the way some highways in the US states have signs alternately reading NO PASSING ZONE and PASS WITH CARE (meaning "end no-passing zone"). --174.89.12.187 (talk) 05:43, 18 April 2023 (UTC)[reply]
Such signs would be posted at underpasses or railway stations; see this video at 1:34. With these things open, sparks could fly off and cause fire damage. For the normal operation, to keep the coal burning hot, they needed to be open.  --Lambiam 07:47, 18 April 2023 (UTC)[reply]
(edit conflict) Regarding point (1). Air normally enters below the grate and passes through the fire for efficient combustion. Some "secondary air" can be introduced above the fire to promote complete combustion (and hence cleaner exhaust). At the point where the primary air enters the ashpan below the grate, the dampers are fitted. They restrict the flow of air, so can "damp down" the fire. They also need to be closed when firing or the hot gasses will come out of the firebox door which is rather dangerous for the crew! The blower would not need to be shut off for firing though, it would pull the gasses away from the crew. Your link show that you've found information on the blower. Invented by either Hackworth or Stephenson (Trevithick mentioned the effect but didn't fully develop the idea) it draws the hot gas through the boiler pipes by using Bernoulli's principle. When would you shut off both? Well tunnels makes sense, you want the minimum amount of smoke hanging around as the train passes. Possibly also in stations or where people might be waiting lineside or where there is a fire risk. A lot depends upon the quality of the fuel and skill of the drivers. Poor quality fuel, poor drivers or slow, heavy freight can eject sparks as well as smoke. One last point, having the blower on implies that the trains are travelling slowly or coasting downhill at that point. At speed the blast from the steam used in the cylinders is powerful enough to draw the fire through the boiler. Martin of Sheffield (talk) 08:07, 18 April 2023 (UTC)[reply]
For an explanation of the role of the сифон, see Thermic siphon. I am not sure of the role of the поддувало ("blower"). It could be a stack blower pulling the hot firebox smoke through the tubes of the boiler, but it could also refer to a soot blower.  --Lambiam 08:08, 18 April 2023 (UTC)[reply]
@Lambiam: I've browsed a bit through related articles in ruwiki and plwiki as well as Google Translate, and it looks like the ru:поддувало is a chamber below the fire grate, where ash and slag fall from the grate. Its name consists of 'дувало' (a device to blow) prefixed with a preposition 'под-' (under, below), and it's actually a channel (when open) where the fresh air is sucked from below into the fire in a coal kitchen stove or a masonry heater. Closing its door significantly reduces the air flow through the stove, so it also temporarily reduces the amount of smoke. --CiaPan (talk) 11:43, 18 April 2023 (UTC)[reply]
I don't speak or read Russian, so can't help with questions 1 and 2. To prevent backblows, you want low pressure in the firebox, so you open the blower and close the dampers (not necessarily completely). Closing the firebox doors also helps, but then you can't put coal on the fire.
It looks like these messages are instructions or hints (I suppose the Soviet Union would issue instructions, whilst the UK would issue hints) to the fireman (whose job it was to manage fire and boiler). Opening the blower or dampers increases the flow or air through the fire, boosting the rate of combustion and production of heat and steam. Way too much air, and burning pieces of coal could be blown out of the chimney, wasting fuel and posing a fire risk. Slightly too much air would still waste fuel and generate too much steam, leading to a very noisy application of the safety valves, something you really want to avoid in a station. Too little air leads to low boiler pressure and, after some minutes, an inability to stick to the timetable, and incomplete combustion, leading to soot and carbon monoxide. In Western Europe, soot was to be avoided in cities and was one reason for electrification, but something tells me that wasn't so much of a consideration in the Soviet Union. Carbon monoxide can be a big problem in tunnels, but those aren't very common in Russia.
Properly managing fire and boiler takes some intelligence. On approach to a station, you stop shovelling coal. Shovelling coal lowers the temperature of the fire, so lower the airflow a bit to compensate. During approach, the regulator is closed, already lowering the flow of air, and the firebox doors may be closed. In the station, you use hardly any steam, so to prevent the smoke from reaching the footplate and the fire from dying completely, you have to open the blower. When departure time nears, you have to anticipate the larger steam demand by putting more coal on the fire. Fresh fuel lowers the temperature, creating more soot, which you don't want in a station, so open de blower a bit more to boost the rate of combustion. Steam production increases; use some to fill up the boiler. If the fireman does his job right, the boiler reaches full pressure and maximum water level right at departure time, with a big fire burning hot to provide steam for acceleration. Now hope that the signal is cleared right away, or you'll get that nasty in-station safety valve application. PiusImpavidus (talk) 10:36, 18 April 2023 (UTC)[reply]

Parrot communication

Has anyone ever studied captive parrots that speak to each other in English/other human languages? They absolutely do sometimes (multiple youtube vids showing it). Thought I might add something to the talking bird or companion parrot article if there was. Iloveparrots (talk) 20:35, 18 April 2023 (UTC)[reply]

Presumably NOT this:[1]Baseball Bugs What's up, Doc? carrots04:11, 19 April 2023 (UTC)[reply]
Did you read Talking_bird#Cognition_controversy? Shantavira|feed me 08:14, 19 April 2023 (UTC)[reply]

Suggest an experiment

Can you suggest a scientific experiment somewhere, if you have the temerity to think you've come up with something worth trying? 2A02:908:424:9D60:5D94:1364:826B:B022 (talk) 20:55, 18 April 2023 (UTC)[reply]

Not on Wikipedia. However, you could write a letter with the suggestion to a scientific news or other journal such as New Scientist, Scientific American, Nature, or various others, many of which specialise in particular fields. The worst that can happen is that you receive no response or a polite dismissal, but if your idea has any possible merit, the Editors(s) might decide to print it in the Letters column where some scientist might be intrigued enough to follow it up. (For possible interest; I have had two letters published in New Scientist, though neither were suggesting experiments, and a thoughtful reply to a third from the Editor, agreeing that a previous article had omitted some relevant facts.) {The poster formerly known as 87.81.230.195} 90.213.18.208 (talk) 22:52, 18 April 2023 (UTC)[reply]
If you're feeling really daring, and your idea has to do with nuclear physics, you can even try writing directly to CERN with your experiment proposal (I remember that the article about the Large Hadron Collider mentions this possibility) -- fat chance of your proposal actually being accepted, but you never know, they might just try it and discover something new! 2601:646:9882:46E0:B06E:637E:D483:879D (talk) 03:02, 19 April 2023 (UTC)[reply]
There are several subreddits devoted to physics. There is even an r/ExperimentalPhysics, but it is not particularly active. If you post your proposal at r/Physics, it may be seen by physicists and picked up if it looks promising. Or readers may offer suggestions, depending on the nature of the experiment, for a better place to forward the proposal.  --Lambiam 06:37, 19 April 2023 (UTC)[reply]
Another avenue is to contact a local institution of higher learning, especially if one has a contact in the relevant faculty. Good luck! cmɢʟeeτaʟκ 09:41, 19 April 2023 (UTC)[reply]
  • If the experiment requires no specialist equipment, you're quite allowed to just "do it yourself". There's generally nothing stopping you (unless the experiment involves activities that are illegal in your jurisdiction). You can even order equipment and supplies, if you have the money to do so. If you want inspiration, there's a YouTube channel, [NileRed, which is run by a guy who rents lab space and has a bunch of equipment to run experiments and film YouTube videos about it. AFAIK, he has no affiliation with any lab or other organization, he's just a guy who likes to do chemistry. If you want more formal structure, you can get involved in various citizen science organizations as well. While having the requisite training and experience in a particular field (like, say, a proper University Degree) and the backing of an organized lab or company certainly helps giving people access to the tools and resources to do scientific experiments, people can do these things all on their own; it's harder, but not impossible, if you have the money and time. --Jayron32 12:14, 19 April 2023 (UTC)[reply]
    That brings to mind the story of the Mpemba effect, discovered by a Tanzanian secondary-school student who then asked a visiting scientist about his observation, got the scientist interested enough to repeat his experiment, and published a paper together. cmɢʟeeτaʟκ 12:33, 19 April 2023 (UTC)[reply]
    Lots of astronomy is done by amateurs as well. David H. Levy is famously the discoverer or co-discoverer of dozens of minor objects orbiting the Earth; he's a trained writer and has little to no formal education in astronomy. --Jayron32 14:01, 19 April 2023 (UTC)[reply]

April 19

Conflicting definitions of systolic hypertension and hypotension

Diastolic vs systolic blood pressure chart comparing European Society of Cardiology and European Society of Hypertension classification with reference ranges in children

While drawing this chart, I was unsure how to shade the bottom-right region (systolic > 140, diastolic < 60 mmHg). Systolic hypertension states

Hypotension states

How should the transition between the regions look like?

Thanks,
cmɢʟeeτaʟκ 09:37, 19 April 2023 (UTC)[reply]

In this scatter plot there are no points in that area. Same here, here and here. This article uses the description "isolated systolic hypertension in combination with diastolic hypotension", which suggests there is no commonly understood specific term for this rare combination.  --Lambiam 21:32, 19 April 2023 (UTC)[reply]

Least Endemic specific area?

Not quite sure the best way to ask the question, but if an asteroid hit/volcanic eruption was to occur in the Galapagos Islands and destroyed everything within 100 km of the hit/eruption, it would completely wipe out a number of species in the wild. I would guess this would be equally true on other isolated islands. My question is the Reverse. Is there any place outside Antarctica where destroying everything within 1000 km of a given point would wipe out *no* species in the wild? My *guesses* would be Siberia (especially on the edge of the Arctic Ocean), the Sahara and Central North America (Centered around the Black Hills of South Dakota?)

Would the same locations be true 10,000 years ago, or (for example) would a hit in Northern Siberia wipe out a species of Mammoth (or one of the large cats that preyed on it).Naraht (talk) 14:55, 19 April 2023 (UTC)[reply]

My guess is that the answer is that no land area on earth as large as 3,140,000 km2 contains zero species which are only within that 3,140,000 km2 area; which is to say that everywhere that large would have some species that exist nowhere else. (that's the area of a circle with radius of 1000 km, FWIW) For example, the Amur lemming has a range smaller than this. If something wiped out everything in that radius, we'd likely lose all Amur lemmings. When you get down to the level of insects and the like, there are MANY such insects which may have tiny ranges; heck 25% of all known species are Beetles alone, many of them with much smaller ranges than you've noted. --Jayron32 15:17, 19 April 2023 (UTC)[reply]
User:Naraht is correct; the taiga biome is utterly depauperate and the only endemic "species" in an given area are likely apomictic dandelions. Abductive (reasoning)

Is it possible to be beaten in the dream and due to it wake up in pain?

Maimonides et al, say in their bible interpretation that the story with Jacob in Genesis 32, 25-31 in which Jacob was limping because of his hip due to the touch of the angle, was in his dream as a part of the prophecy. Nachmanades, on the other hand, rejects this opinion because the bible states that Jacob was limping, so it must happen in reality. Maimonides's son, Abraham Maimonides (and others) explains that despite that all this story was in his dream, one can wake up in pain due to fighting or so. As proof, he mentions the wet dream, that one can see a sexual attractiveness that can cause ejaculation. Now my question is: Is Abraham Maimonides opinion supported scientifically or rejected? ThePupil (talk) 19:15, 19 April 2023 (UTC)[reply]

Medically unexplained physical symptoms are well documented. It's entirely plausible that a person can feel pain as a symptom for which there is no clear physical antecedent; by definition, a symptom is "a person's reported subjective experiences", experiences of pain are not normally observable by anyone except the person experiencing the pain. --Jayron32 19:28, 19 April 2023 (UTC)[reply]
As far as self-observation goes, I am inclined to think that it is the physical need to ejaculate excess seminal fluid (which is continually secreted) that often (though not always) induces a sexual dream, not the other way around. I have on occasion dreamed of urination rather than sexual activity in the circumstance.
On a different note, I have sometimes dreamed of something that affects vision, such as being blinded by a bright light, or reading lines of printing that in real life tends to leave reversed afterimages, and then woken up in near darkness but experiencing those visual effects.
Perhaps Jacob experienced a pain-causing problem with his hip (a camel kicked him while he was asleep maybe?) that caused him to dream of wrestling with an angel, rather than the reverse. {The poster formerly known as 87.81.230.195} 90.213.18.208 (talk) 03:04, 20 April 2023 (UTC)[reply]

April 20