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May 9

LED lighting dimmer switch

Can you tell me about this? Does it it exist yet?

I now have parrot bird with red eyes and if you turn the light on from dark to light it drops him on his back. So I can't use LED bulbs in his room. Because previously I used a dimmer to bring light up gradually. Can you tell me? Thank you. Iqbal. 146.200.107.107 (talk) 02:15, 9 May 2024 (UTC)

Yes. They exist. I just went to the web site of my local hardware store, searched for "led dimmer switch" and found several. HiLo48 (talk) 02:25, 9 May 2024 (UTC)

There are also dimmable LED light bulbs that can be used with most types of dimmer.^[1]  --Lambiam 06:02, 9 May 2024 (UTC)

There are also led light bars that can be programmed for a gradually changing brightness and colour to simulate sunrise and sunset. Some even support simulating random clouds passing in front of the sun and the occasional thunderstorm with lightning. Aquarium lights tend to have such features. PiusImpavidus (talk) 12:13, 9 May 2024 (UTC)

Note that dimmable LEDs don't dim the same way incandescents do.

When incandescents dim, a lower level of power continues to be continuously conducted through the filament. The lower power produces less light.

LEDs don't really have variable brightness in response to different levels of power the same way incandescents do. Instead, they're dimmed by flickering them on and off at an extremely high frequency. The frequency is too high for our eyes/brains to perceive the flickering; but since they're not on all the time, less total light is emitted.

In order to respond to a decrease in power this way, the LED bulb needs to have specialized hardware in its base. So you'll have to buy special "dimmable" LED bulbs. I've had very mixed experiences with these, fwiw, and some that are nominally dimmable don't dim well or at all. Others produce extremely unpleasant light at lower levels. -- Avocado (talk) 20:33, 9 May 2024 (UTC)

Specifically, incandescent lights (is there anyone still using those? They've been banned in the EU for over a decade) can be dimmed by reducing the root-mean-square voltage over the filament. This lowers the light output, makes it redder and lowers the efficiency. Leds have constant colour and the brightness is controlled by electronically controlling the average current. Pulse-width modulation appears to be the simplest efficient way to control the average current. Dimmable led lights have some electronics that take the input voltage as a cue to change pulse width. Flicker is invisible to humans, but may appear when there's some beating with another periodic process of similar frequency (spinning things, cameras). A simple low-pass filter would eliminate the flicker. PiusImpavidus (talk) 07:54, 10 May 2024 (UTC)

Yeah, you can still buy incandescents in the US. They keep partially walking back the bans. And they're still allowed for specialty purposes (like heat lamps and candelabras), and maybe at low wattages? I've also recently seen incandescent bulbs with purportedly higher efficiency than old ones being sold in places -- I'd be unsurprised if our regulations are weak. And maybe leftover inventory is still allowed to be sold? Small retailers I think get them under the table from ... somewhere. If you search a major hardware store's site, you'll find a selection still for sale. Here's what we've got on the topic. -- Avocado (talk) 13:17, 10 May 2024 (UTC)

The flicker fusion threshold of birds is much higher than humans, up to 140 Hz (see this article). So a dimmed LED light that looks merely dim to us may appear to be flickering to a bird. I can imagine that that might be as unpleasant to a bird as a flickering light is to humans. Maybe some LEDs have a phosphorescent coating that absorbs and reemits the light after a delay, thus temporally buffering the light output, which might settle the parrot. Otherwise perhaps it is better to dull the light using a translucent screen or by reflecting the light off a surface. JMCHutchinson (talk) 11:43, 10 May 2024 (UTC)

Yeah, even as a human (hello, fellow humans!), I find dimmed LEDs to produce a very unpleasant light. I wonder if we can detect the flickering subconsciously even if we consciously can't? There's a theory that we can with fluorescents (which flicker even at full brightness), causing a bit of dysphoria in flourescent-lit spaces. -- Avocado (talk) 13:05, 10 May 2024 (UTC)

I have noticed that I can sometimes see flicker with peripheral vision that I can't when looking directly: aaand I see this is mentioned in the article. Flicker fusion threshold may also be of interest. {The poster formerly known as 87.81.230.195} 188.220.175.176 (talk) 14:57, 10 May 2024 (UTC)

Ambivert vs. omnivert

Is there a difference between ambivert and omnivert, or are these the same? 2601:646:8082:BA0:24BD:2FE2:B975:68AE (talk) 06:13, 9 May 2024 (UTC)

• Saucedo, Kayla (29 January 2024). "Ambivert Vs. Omnivert". simplypsychology.org. Simply Scholar Ltd. --136.54.106.120 (talk) 16:08, 9 May 2024 (UTC)

OK, thanks! So, an ambivert is someone who's near the middle of the scale all the time, whereas an omnivert is someone who goes from full extrovert to full introvert and everything in between? 2601:646:8082:BA0:CD56:E11E:9CF:F450 (talk) 02:45, 10 May 2024 (UTC)

Some researchers have questioned the validity of personality tests.^[2][3][4] I doubt that the validity of the specific labels ambivert and omnivert has been seriously studied; they may be pure pop-psych products. Also, even when valid, it can be questioned whether all this labeling isn't more harmful than beneficial.^[5]  --Lambiam 08:29, 10 May 2024 (UTC)

I hope you're not also questioning the validity of the labels extrovert and introvert, are you??? And if these are valid terms (which they are), then we also need a term for someone who's in the middle of the scale! 2601:646:8082:BA0:448D:8CB2:2FBC:B6C7 (talk) 23:19, 10 May 2024 (UTC)

Do we also need a term to label people who are halfway between introvert and omnivert? One problem with these personality tests is that they do not depend on a person's actual behaviour, but on their self-reported interpretation of their self-imagined behaviour in hypothetical, vaguely described situations. Validity as a personality label requires IMO consistent reproducibility over time, not of such self-reports, but of actual behaviour in a context of actual situations. I don't expect this stuff will be able to hold itself up well against the scientific method.  --Lambiam 06:34, 12 May 2024 (UTC)

Did you not read any part of this section other than your own comments??? First of all, as already explained above, the definition of omnivert is not that of someone occupying a certain position on the scale, but someone who fluctuates between extroversion and introversion, and hence there can be no "halfway" between omnivert and anything else! And as for the others, yes we do need specific terms for the far ends of the scale and also for the middle -- this is standard for any property which exists along a continuum! Also, I've personally taken both the ocean test and the MBTI test, and I can tell you, the situations described in the current versions are quite specific and mostly applicable to real life (at the very least, with the disclaimer that I'm one of the most pronounced introverts ever, I had no problems with the questions being "vague" or not applicable to me personally), so your criticism of these tests (at least in their current versions) is completely misplaced! And, as far as your demands for observation of "actual behaviour" (your emphasis, not mine), this would require a Big Brother-style system of constant and pervasive surveillance of your test subjects, which is completely impractical, highly illegal and unethical, and would itself introduce bias into your observations should your test subjects become aware of it (due to them modifying their own behavior to conform to perceived social norms out of fear of judgment) -- so, the stuff you propose wouldn't be able to hold itself up against the scientific method either (not to mention that it would most likely be disallowed on legal and ethical grounds)! 2601:646:8082:BA0:C178:97BE:AF93:9928 (talk) 09:41, 12 May 2024 (UTC)

You yourself wrote, "we also need a term for someone who's in the middle of the scale", i.e., between "the labels extrovert and introvert". This is what the term ambivert purports to signify. I responded to the claim of this need, wondering why there should be a need to label the extremes and one point in the middle, but not other points on the scale?  --Lambiam 20:12, 14 May 2024 (UTC)

Because then all of the other points on the scale can be visualized and described in relation to these 3 points -- whereas if only the two extremes were labeled, then it would not adequately describe those who are close to the middle! 2601:646:8082:BA0:BC05:6EA8:F933:9E6D (talk) 11:07, 15 May 2024 (UTC)

Not if they agree to it first, IP-hopper. As to this "omnivert" notion, it could be called "situational". Many people are more comfortable in certain settings than in other settings. That's "normal". ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:49, 12 May 2024 (UTC)

Maybe if they give fully informed consent it might be legal, but then you run into the other problem I mentioned (which you conveniently ignored) -- if they know they're being watched, they won't act like their normal selves (and the more you watch them, the more they'll put their guard up), so you won't see their "actual behaviour" in "actual situations", and you'll get skewed results! 2601:646:8082:BA0:28E6:4E7D:4BB4:DD49 (talk) 20:01, 12 May 2024 (UTC)

That would be tragic. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:51, 12 May 2024 (UTC)

That is just how people work -- and that is the reason why self-reporting of actual behavior is the best you can get in terms of data! 2601:646:8082:BA0:692F:1147:32D5:BCAA (talk) 01:54, 13 May 2024 (UTC)

Cultural anthropologists study actual behaviour. They don't go around handing out questionnaires.  --Lambiam 07:03, 15 May 2024 (UTC)

This is in the realm of psychology, though, not anthropology (cultural or otherwise) -- which brings up yet a third problem with your proposed methodology, that merely observing the behavior of your test subjects will not reveal what's going on inside their head at the time, and thereby also give you inaccurate results! (For example, an introvert like me might be forced against his/her will to attend an office party and even to mingle with other people thereat (and even to feign cheerfulness while doing so), which your methodology will register as extroverted behavior and will simply not see how miserable it makes him/her -- or, just to cover both sides, an extrovert might be forced to spend time working or studying alone, which your methodology will register as introverted behavior and not see how much he/she hates it!) And you still haven't answered how you would counter the observer effect (which, in this scenario, would manifest itself on a very macroscopic scale due to the fact that, as I already said, many people simply won't act like their own natural selves when they know they're being watched all the time)! 2601:646:8082:BA0:BC05:6EA8:F933:9E6D (talk) 11:07, 15 May 2024 (UTC)

And also, I see a fourth problem with this kind of methodology, and that has to do with sample selection bias -- introverts are far less likely to volunteer for an experiment in which their actual behavior would be monitored, especially if this includes being monitored inside their own homes, and the more introverted a person is the more likely he/she would refuse to take part in such an experiment (as an introvert from the deepest end of the scale, I personally know I would refuse without thinking twice), so you'll get a sample which is skewed toward extroversion, and that would also give you inaccurate or incomplete results! (This, indeed, is one area in which the current methodology of anonymous self-reported personality tests with hypothetical questions about various social situations is superior to any other suggested here -- there is something inherently reassuring about knowing that only me and the machine see the actual personal responses, especially for an introvert like me -- and this makes it better in terms of reducing sample bias than even self-reporting of actual behavior, because the latter cannot easily be reduced to a machine-processable series of multiple-choice questions and would require short-answer questions to be interpreted by a human psychologist, and knowing that an actual human sees your individual responses and your identifying data is much harder to swallow, especially given that being judged by a psychologist might (sometimes) have real-world consequences!) 2601:646:8082:BA0:2D37:9C1D:9DB2:251E (talk) 13:36, 17 May 2024 (UTC)

May 10

Insect repellent

Do all pyrethrin analogs have broad-spectrum insect repellent properties in less-than-lethal concentrations? 2601:646:8082:BA0:CD56:E11E:9CF:F450 (talk) 01:56, 10 May 2024 (UTC)

It says here that "Before the emergence of resistance, an early hut trial in The Gambia concluded that permethrin was the most repellent pyrethroid, followed by λ-cyhalothrin, deltamethrin, and lastly cypermethrin". This suggests that there must be some in the list of 29 examples in the pyrethroid article that are much worse repellents. I would guess that the stronger the odor, the better the repellent effect. Abductive (reasoning) 08:38, 10 May 2024 (UTC)

Pyrethroids were designed to kill insects and are used, for example, to control malaria-carrying mosquitoes by treating bed-nets. In this and other agricultural applications, repellence is an unwanted property particularly if the non-lethal effect allows insect populations to build up resistance. There are, of course, compounds designed to act only as insect repellents, of which the best known are probably DEET and citronellal. Mike Turnbull (talk) 10:46, 10 May 2024 (UTC)

Thanks! So, not all of them, but many of the common ones -- which is great for me (they're painting my front door today, so I have to enforce a no-fly zone outside it :-( ) And yes, last time I've personally witnessed the repellent effect of 200 ppm deltamethrin against Papilio multicaudata (or maybe it was a large P. rutulus, but my money is on the former) and P. eurymedon, as well as multiple Apocrita species! (The repellent effect, indeed, is what I'm looking for here -- I don't care if the bugs survive or die, I just don't want them to fly into the house or get anywhere near me!) 2601:646:8082:BA0:59E2:271:87C3:F3E (talk) 14:07, 10 May 2024 (UTC)

Also, one of the two cans I used today had a mixture of prallethrin and cyfluthrin which was specifically formulated as an insect repellent, so we can add these two to the list as well -- although, from personal observation, their repellent effect was actually less than that of deltamethrin! 2601:646:8082:BA0:448D:8CB2:2FBC:B6C7 (talk) 00:12, 11 May 2024 (UTC)

May 12

ecological spray bottle

does anyone know if there are any glass or metal spray bottles with bioplastic triggers and straw available anywhere in existence? i really want to go plastic free for my succulent business ninosckasnaturals.com 2600:1700:9758:7D90:B406:C016:3BC0:D48B (talk) 06:05, 12 May 2024 (UTC)

Maybe one of those old-fashioned perfume misters with the rubber squeeze bulb? I doubt very much that there is a mass-produced non-plastic alternative spray bottle apparatus. Abductive (reasoning) 21:49, 12 May 2024 (UTC)

There are pump-type plant misters (e.g. metal or glass). --136.54.106.120 (talk) 18:27, 13 May 2024 (UTC)

P.s.: LOOPSEED sells stainless steel plant mister spray bottles in various finishes, well-suited for succulents (search online for details). --136.54.106.120 (talk) 18:49, 13 May 2024 (UTC) -- [edit: 22:33, 13 May 2024 (UTC)]

origin of the formula for LC frequency

In electricity, properties known as inductance and capacitance together can resonate. The formula for the frequency of resonance is 1/(2*Pi*SQRT(L*C)). Who first published this formula? ```` Dionne Court (talk) 06:33, 12 May 2024 (UTC)

Somewhat after Laplace 1800 and before Poincarre, 1899 with a strong suspicion that the ubiquitous Maxwell might have done it. Greglocock (talk) 06:57, 12 May 2024 (UTC)

According to LC_circuit#History it was the ubiquitous Lord Kelvin in 1853. --Wrongfilter (talk) 07:10, 12 May 2024 (UTC)

Thank you. That man did everything. Greglocock (talk) 23:49, 12 May 2024 (UTC)

It does say that, but it is incorrect, which is why I posted here. Kelvin derived an equation to describe the transient response (response to a one-time shock excitation). However the article io LC_circuit#History gave as a reference an article in the Bell System Technical Journal, 1941, pages 415-453. I have now obtained this paper and it gives James Clerk Maxwell as the first to give the resonance formula (in a different but mathematically equivalent form), in a letter published in Philosphosical Magazine 1868. I will try and get this letter. ```` Dionne Court (talk) 03:13, 13 May 2024 (UTC)

It is this letter.  --Lambiam 12:14, 13 May 2024 (UTC)

It's from the right guy and via the correct other guy, but it has no math in it at all. It is not therefore the earliest statement of the resonance formula.

I'm looking for the fist statement of the formula as given in modern textbooks, i.e.,

f = 1/(2π(LC)^½).

It is a trivial exercise in algrbra to convert Maxwell's form into the standard modern form, but I would like to know when the modern form was first give. Dionne Court (talk) 00:29, 14 May 2024 (UTC)

The section entitled Mathematical Theory of the Experiment, an enclosure to the letter immediately following it on page 361, definitely contains some maths. On page 363 we see the equation ${\text{CL}}n^{2}=1,$ which results in an amplitude that, Maxwell writes, "is the greatest effect which can be produced with a given velocity". In this formula, the "velocity" $n$ is what is now more commonly denoted with the Greek letter $\omega .$  --Lambiam 06:49, 14 May 2024 (UTC)

p 540 onwards in Mathematical and Physical Papers, Volume 1 William Thomson Baron Kelvin University Press, 1882 - Mathematics - 619 pages, which is in google books, certainly discusses oscillatory behavior and time between peaks but I don't think it explicitly states f=1/(2pi*sqrt(L*C)). Particularly equation 7 where his A is modern L. Greglocock (talk) 00:08, 14 May 2024 (UTC)

May 14

Cranial size and Pb poisoning

Hello, can lead poisoning affect cranial size?Rich (talk) 05:43, 14 May 2024 (UTC)

Yes.^{[6] [7] [8]} --136.54.106.120 (talk) 11:40, 14 May 2024 (UTC)

May 15

They see me rollin', they hatin...

Question for you guys. Is there any animal whose primary method of locomotion is curling into a ball and rolling head over heels to get around? Rather than running or walking. Because I think some woodlice do it (faster for them to roll then run), but I'm not 100% sure. Iloveparrots (talk) 03:04, 15 May 2024 (UTC)

Do fictional animals count? --136.54.106.120 (talk) 03:33, 15 May 2024 (UTC)

Terrestrial locomotion #Rolling may be of interest. --136.54.106.120 (talk) 03:38, 15 May 2024 (UTC)

I don't see how that could ever be a primary means of locomotion, but see also Category:Rolling animals. Shantavira|^{feed me} 08:37, 15 May 2024 (UTC)

Hedgehogs do it to escape from predators when threatened. 2601:646:8082:BA0:BC05:6EA8:F933:9E6D (talk) 10:43, 15 May 2024 (UTC)

Hedgehogs roll up for protection, not for locomotion. (Ditto for the woodlice mentioned by the OP). Iapetus (talk) 11:57, 15 May 2024 (UTC)

I don't think I've ever seen a hedgehog roll outside of a video game. But then again, I've only ever seen hedgehogs in real life about three times. Iloveparrots (talk) 22:58, 15 May 2024 (UTC)

Hedgehogs do not purposely roll when in a defensive ball. They "huff", which makes them bounce, forcing their quills into whatever is attacking them. That bounce could cause a roll, but it isn't on purpose. 75.136.148.8 (talk) 13:40, 16 May 2024 (UTC)

See Rotating locomotion in living systems. 2605:B100:34D:46C3:61A4:6B17:A082:3780 (talk) 12:27, 15 May 2024 (UTC)

I have encountered assertions that Giant pandas, when sitting in a bamboo thicket on a slope, will sometimes roll a short distance rather than get up and walk, but this would need confirmation from a reliable source, and in any case would not be a primary means of locomotion. {The poster formerly known as 87.81.230.195} 94.2.67.173 (talk) 19:48, 15 May 2024 (UTC)

A giant panda is rolling head first in this video: Panda Discovers Something Interesting. They roll about a lot too, for various reasons. Modocc (talk) 23:30, 15 May 2024 (UTC)

What's the max depth of the Baltic, Black and Azov brim?

The depth where it stops being connected to the World Ocean 50% of the time (connected only by seepage through porous solids like silt not counting as connected). As the brim can erode, shift if the water's removed, be a V-notch in a ridge etc and even if it's dredged wide, straight and flat it might not be legal to lightly touch the silt so this might not round to the same number of feet as the deepest draft ship that's allowed at least 50% of the Metonic cycle, or how much sea level would have to drop to make it a lake 50% of the time. Also what would the depth be if the strait bottom wasn't landscaped? The Turkish Straits are pretty deep by ship standards maybe they aren't landscaped? Sagittarian Milky Way (talk) 18:05, 15 May 2024 (UTC)

They wouldn't need to be "landscaped", the Bosphorous is typically about 60 m deep with a 40 m sill towards its southern end, although the Asian side of the strait at that point is somewhat shallower (about 27 m) - see Siddall et al. (2004). Mikenorton (talk) 19:11, 15 May 2024 (UTC)

Right I didn't think they would. Unless the depth of the rim's now artificial by more than a foot due to sinking accidents(s), full or partial intentional blockages or explosion(s) (possibly to clear some of the previous)? Or maybe it's still the natural rock or sediment accumulation-erosion surface? I don't know if the Baltic and Azov brim are unaffected by human landscaping. Sagittarian Milky Way (talk) 20:16, 15 May 2024 (UTC)

May 17

What would cause these 'dark area' blemishes on an LCD monitor?

See this photo: https://ibb.co/mz8vQh0

This is my Asus Designo MX25AQ main monitor, I've had it for a little over four years and two months now. Since about a year ago, it started developing this issue where a "wavy" area of darkness appears near the left and right edges of the screen. It looks as if there's liquid in the screen or if something's "delaminating" inside. It would usually happen when it's cold, and would go away / "fade away" as it warmed up (usually taking a few minutes). However, over the last few months, it's been getting worse and worse. Nowadays, sometimes it's visible on certain shades of colours even when the monitor is fully warmed up. It is especially noticeable when it cools down in real life (e.g. it's becoming dawn and the brightness has been decreased).

The "grey uniformity" of the monitor has been degrading a bit as well, I swear.

I know I likely won't be able to fix an issue like this with the LCD panel. But my question is, what would possibly cause these issues? Could it develop into a stage where my LCD becomes completely / severely broken?

Note that I'm posting this to RD/S and not RD/C because I strongly believe this issue has something to do with materials degradation in the LCD and not some issue with the computer or cable, so I figured this is a better place for that.

Apologies for the non-free external image site upload, but if everything you see in the photo is not copyrighted then I will upload it to Commons. — AP 499D25 (talk) 05:03, 17 May 2024 (UTC)

I Googled around, and it could be moisture infiltrating around the edges. The fact that it clears when hot is suggestive of that. There was a suggestion that if the monitor is near a kitchen, these stains could include cooking fumes. Another possibility (and conceivably related) is damage from pulling the protective plastic sheet off, the one that came when the monitor was newly purchased. This has to be done extremely carefully. Yet another worry is cleaning with rubbing alcohol, the internet says this is a bad idea. Abductive (reasoning) 06:11, 17 May 2024 (UTC)

Rubbing alcohol as sold can consist for up to 50% of water.  --Lambiam 09:16, 18 May 2024 (UTC)

That sounds plausible! Thinking about it, more than a year ago I did clean my monitor using a wet microfibre cloth (a small, thin one for phones), and that seems to be the timepoint it all started. Worth pointing out that this monitor is in a bedroom, so it's not near moisture or oil vapour sources, and it has never been used in such an environment. When I got it new, there wasn't actually a protective sticky film on the front, just a styrofoam wrap. When I slid that wrap off, I got a nice big static shock when I touched the monitor bezel, but that didn't seem to do any immediate damage – this monitor was fine for the first 2.5 years or so that I used it.

Another interesting fact about this monitor is that although I bought it in Mar 2020, according to the info label, it has an manufacture date of Sep 2015, so that means it sat in a warehouse for 4.5 years before I bought it I guess.

Aside from this annoying and distracting issue, this monitor is the best quality display I've ever had (QHD resolution and 100% sRGB accuracy), so it'd be such a shame if it's actually dying on me. — AP 499D25 (talk) 08:06, 17 May 2024 (UTC)

Is there any scientific truth to the meme that Vegetable oil/Seed oil is toxic to the human body?

There are plenty of memes that seed oil causes diabetes and heart attacks but I failed to find any wikipedia articles that argues their case. Is there any scientific truth to the meme that Vegetable oil/Seed oil is toxic/harmful to the human body?

Another question is that if the meme of harmful seed oil is unscientific then why isn't this meme documented in the List_of_conspiracy_theories wiki page? 2001:8003:429D:4100:A593:8A5B:182E:5551 (talk) 15:55, 17 May 2024 (UTC)

Any kind of fats or oils in excess can cause heart disease, but there is no truth to the claim that vegetable oil is more toxic than animal fats (in fact, it's actually healthier) or that its consumption in moderation causes any health problems. 2601:646:8082:BA0:9480:50AE:ABF3:5E17 (talk) 23:30, 17 May 2024 (UTC)

Yes, there is truth to it. Our nutrition articles could do with some updating and balance. It is a prime example of Paracelsus's The dose makes the poison, for both the omega 6 LA and omega 3 ALA are essential nutrients for humans. The basic issue is consumption of a high quantity of omega-6 fatty acids from modern seed oils (which have only been consumed for a century or so) and other sources, including indirectly through animal feed and the (relative) paucity of omega-3 fatty acids in the modern human diet. [Excessive omega-3 over omega-6 has been found only in Greenlandic Inuit traditional communities.] Probably the best book to start with is Anthony John Hulbert's recent Omega Balance: Nutritional Power for a Happier, Healthier Life- Johns Hopkins (2022). By omega balance, he means the percentage of omega 3's in the sum of omega 3's and 6's. He says:

Although there is no advice about separate consumption of omega-3 and omega-6 fats in these national dietary guidelines, this is not the case with the premier scientific society concerning lipid research. In 2004, ISSFAL (International Society for the Study of Fatty Acids and Lipids) issued a series of recommendations for dietary intake of the essential fats by healthy adults. They made no comment about consumption of the nonessential saturated and monounsaturated fats but instead proposed that adequate intake of 18:2ω-6 [ Linoleic acid (LA) ] is 2 percent of energy, and a healthy intake of 18:3ω-3 [ α-linolenic acid (ALA) ] is 0.7 percent of energy as well as recommending a minimum intake of 500mg/d of 20:5ω-3 [ eicosapentaenoic acid (EPA)] and 22:6ω-6 [sic, should be 22:6ω-3 docosahexaenoic acid (DHA) as in the source [9]]. These ISSFAL recommendations for daily intake correspond to a diet omega balance of about 30 percent. The recommended intakes contrast markedly with the average actual daily intakes by the US population (from a 1999–2000 survey), which correspond to a diet omega balance of 9 percent. Similarly, a dietary survey of the Australian population revealed the average daily intake in 1995 corresponded to a diet omega balance of 11 percent. Both the United States and Australia (and likely many other developed high-income countries) have omega-6 intakes much higher and omega-3 intakes lower than the recommended levels.

Hulbert and other sources provide evidence that the omega imbalance can have deleterious effects not only in various chronic diseases, but also that the excess of inflammatory omega-6's can worsen outcomes of Covid, where many deaths appear to come from an excessive inflammatory response.John Z (talk)

μ-Oxidodihydrogen, a chemical compound found in industrially processed canned soup, is also known to be toxic to the human body. Why is no one talking about this?  --Lambiam 09:10, 18 May 2024 (UTC)

In very large excess, such as Olympic sized swimming pools, you would find it extremely difficult to swim in oil. Graeme Bartlett (talk) 12:37, 20 May 2024 (UTC)

It might be even more difficult in a bathtub.  --Lambiam 19:31, 20 May 2024 (UTC)

A wry comparison to the dangers of water is appropriate to much or most discussion of nutrition. Which proceeds by demonizing food X and then along with declaring it causes disease Y, X is declared to be a novelty even though it was consumed by all or much of humanity for tens of millennia at least, or is even essential to life. Historical absurdity is absurdly accepted. But it isn't relevant here because nobody considers modern seed oils to be anything but essentially new foods, never existing or consumed in such bulk before by humans or by any animal. And there aren't many such candidates for widespread dietary changes that could be implicated in global rises of chronic diseases.

Another source, which may conceal some such wryness, is Harumi Okuyama, Yuko Ichikawa, Yueji Sun, Tomohito Hamazaki, William Edward Mitchell Lands- Prevention of Coronary Heart Disease: From the Cholesterol Hypothesis to omega 6 omega 3 Balance- Karger (2006). They note that "Dietary advice was revealed to be the most serious risk factor for CHD in Japan." "We suggest that increased intake of LA [a consequence of that advice as it raised seed oil consumption] may be a major cause for the observed increase in CHD incidence in the group with dietary advice. Higher intakes of LA accompanied higher rates of CHD ( fig. 9–11 ; tables 4 , 5 ), whereas decreasing LA intake was effective for the secondary prevention of CHD events". In any case, there is a genuine, active scientific controversy here, not a conspiracy theory. Those who see omega imbalance as a real problem - and therefore seed oils, which uncontroversially are its ultimate source- may be the majority of specialist lipidologists, e.g. Artemis Simopoulos, cofounder of ISSFAL.John Z (talk) 04:20, 21 May 2024 (UTC)

Butterfly size

Do butterflies (especially nymphalids and/or swallowtails) become significantly smaller in size near the poleward (high-latitude) limit of their natural range? When I visited the Royal Ontario Museum in Toronto, they had 2 pinned specimens of Papilio cresphontes on display which were much smaller than their normal size per the article (one had a wingspan of "only" 3 inches -- I did a rough measurement with my fingers against the glass -- and the other was about 1/2 inch bigger) -- is this normal for (1) specifically P. cresphontes, (2) all swallowtails, and/or (3) all or most butterfly species? 2601:646:8082:BA0:9480:50AE:ABF3:5E17 (talk) 23:38, 17 May 2024 (UTC)

Size Distributions of Butterfly Species and the Effect of Latitude on Species Sizes (you can open a free JSTOR account or access through the Wikipedia Library). Alansplodge (talk) 10:10, 18 May 2024 (UTC)

Sorry, I won't click on any external links regarding this topic, just in case it might show me gratuitously enlarged pictures of P. multicaudata or some suchlike abomination -- can you just tell me the gist of it in a few words (or more than a few, your choice)? 2601:646:8082:BA0:E558:16C8:D2DE:51EF (talk) 10:31, 18 May 2024 (UTC)

There are no pictures, it's a scientific paper. "For butterfly species (Papilionoidea) of the Australian and Afrotropical regions, average wingspan decreases with increasing latitude". Alansplodge (talk) 10:34, 18 May 2024 (UTC)

Thanks! So the answer is yes -- right? (And that would explain the unusually small size of the two P. cresphontes specimens at the museum -- they must have been caught locally, and Toronto is near the northern limit of this species' natural range! And that is also quite reassuring for me -- it means that in Portland, Maine where I've been planning to move for quite a while, any P. cresphontes I come across won't be scary huge, in fact I might actually come to like them!) 2601:646:8082:BA0:E55E:2854:FEDE:FEB6 (talk) 21:21, 18 May 2024 (UTC)

May 18

Why packaging is important

Two reasons why packaging is important PhuPhumzile (talk) 07:10, 18 May 2024 (UTC)

Please do your own homework.

Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. Shantavira|^{feed me} 09:16, 18 May 2024 (UTC)

• Read our article on "Packaging". It may assist you. Graeme Bartlett (talk) 09:40, 18 May 2024 (UTC)

Ya gotta love it when a poster doesn't even try to make it look like a question they thought of on their own. Or like a question, even. ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:23, 18 May 2024 (UTC)

One reason: By packaging your homework question to make it look as if it is curiosity-driven, you have a much better chance of getting a useful answer.  --Lambiam 14:41, 18 May 2024 (UTC)

Why packaging is important: try buying loose helium by weight. Or by the handful. AndyTheGrump (talk) 15:30, 18 May 2024 (UTC)

In certain forms shrinkflation, despite selling less of a product, manufacturers keep the packaging at the original size and leave some of the space empty. This wrapping and transportation of air maintains the level of economic activity, which is important to the gross domestic product.  Card Zero  (talk) 21:22, 20 May 2024 (UTC)

May 19

Erythema Migrans

Hi

Does anyone have a good source for erythema migrans? I was looking for another one and can't copy (for my own notes) the Wikipedia page

W;ChangingUsername (talk) 19:04, 19 May 2024 (UTC)

Erythema migrans. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:19, 19 May 2024 (UTC)

I just came from there. The article isnt very good im sorry W;ChangingUsername (talk) 21:02, 19 May 2024 (UTC)

This Google Scholar search reduces the number of results from 19,400 to 11,900 by adding the term "review". Abductive (reasoning) 11:10, 20 May 2024 (UTC)

Thank you :)

I'll probably start using this for everything W;ChangingUsername (talk) 18:50, 20 May 2024 (UTC)

May 20

Can testosterone boost/etc... change someone desire from responsive to spontaneous?

Can testosterone boost/etc... change someone desire from responsive to spontaneous?177.207.104.19 (talk) 01:37, 20 May 2024 (UTC)

What do you mean? ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:39, 20 May 2024 (UTC)

See Sexual desire and various other related articles, which you could have found easily by putting 'responsive desire' into the search box of this encyclopedia. You often post similar nonproductive responses to things which you personally have not heard of, although many others have: it becomes tedious. {The poster formerly known as 87.81.230.195} 94.2.67.173 (talk) 11:58, 20 May 2024 (UTC)

I see no harm in trying to encourage posters to link to what they're asking about. ←Baseball Bugs ^{What's up, Doc?} carrots→ 12:44, 20 May 2024 (UTC)

To be fair, there was a non-zero chance that it referred to a responsive to spontaneous change in the desire to fight strangers. Sean.hoyland (talk) 13:01, 20 May 2024 (UTC)

Theoretically. The funny thing is that the first sentence of 94.2.67.173's lecture to me could just as easily have served as a direct response to the poster. (Though maybe that was the point anyway!) ←Baseball Bugs ^{What's up, Doc?} carrots→ 14:40, 20 May 2024 (UTC)

You may be thinking of the DRD5 gene, where some alleles are thought to be involved in spontaneity or lack thereof. Abductive (reasoning) 11:15, 20 May 2024 (UTC)

Our article doesn't mention that, but implicates it in everything else: learning and memory, addiction, smoking, ADHD, Parkinson's disease, schizophrenia, locomotion, regulation of blood pressure, and immunity. What a busy gene. I guess you're referencing something along the lines of dopamine being important for the will to initiate movement, like in Awakenings.  Card Zero  (talk) 21:32, 20 May 2024 (UTC)

According to this review article, "of the few studies on T[estosterone] and desire in healthy women ... dyadic desire [desire in sex with a partner] has shown null or negative correlations with T". This suggests it is unlikely to achieve the specific effect.  --Lambiam 08:58, 21 May 2024 (UTC)

Gregory Cochran

Has Gregory M. Cochran worked for Darpa? If so, in what capacity, if known?Rich (talk) 21:45, 20 May 2024 (UTC)

This Gregory Cochran would be a likely candidate, but I could find no direct evidence to support this. This Gregory M. Cochran seems less likely. There was a 'Doug Cochran' at DARPA, however. --136.54.106.120 (talk) 01:09, 21 May 2024 (UTC)

I bet those 2 Gregory Cochrans are the same.Rich (talk) 02:27, 21 May 2024 (UTC)

You're correct: they each are "co-author of the book The 10,000 Year Explosion." That Edge link could be used as a source for updating the article. --136.54.106.120 (talk) 05:57, 21 May 2024 (UTC)

May 21

Butterflies of Daviess County, KY (Papilionidae)

In Daviess County, Kentucky (or generally along the Ohio River or within a reasonable distance south thereof), how late in the year was the latest-ever sighting of Papilio glaucus? (Here in Central California, all tiger swallowtail species disappear in the first days of September -- my latest confirmed sighting of P. multicaudata was on September 1, and of P. rutulus on September 4 -- is it more-or-less the same over there?) Asking for a local and/or an expert -- and no pictures, please! 2601:646:8082:BA0:250E:98C8:7461:C819 (talk) 02:48, 21 May 2024 (UTC)

The pool of active RefDesk editors is quite small and is spread around the Anglosphere (or sometimes outside of it), so finding anyone from that locality or an entomologist here is a bit unlikely. A Google search only found backyardecology.net - Eastern Tiger Swallowtail Butterflies (with pictures) which says: "In Kentucky, we typically see the adults flying from April until September". Alansplodge (talk) 14:33, 21 May 2024 (UTC)

Broadening the topic somewhat, you might be interested (if you aren't already familiar with it) by the subject of Phenology. Climate change is obviously having a large influence on previously reliable annual timings of natural phenomena: in my part of the world (southern England), many trees are blooming, etc., up to a month earlier than a few decades ago. Doubtless the emergence, migrations and numbers of annual broods of insects are also changing, so they can appear later as well as earlier. {The poster formerly known as 87.81.230.195} 94.2.67.173 (talk) 09:57, 22 May 2024 (UTC)

Try calling 270-684-0211, the main number for the county public library in Owensboro. (Lest you embarrass yourself — be aware that the county name is pronounced "Davis", not "Davey's" or "Davy-ess".) Unfortunately their website's "contact" page, https://www.dcplibrary.org/contact, doesn't give either an email address or a form to write a help request. Nyttend (talk) 02:18, 23 May 2024 (UTC)

Pseudouridine - why is it the fifth nucleotide?

I saw that in the scientific literature, pseudouridine is considered the fifth nucleotide. For example:[10], [11]. My question is why is it called the fifth and not the sixth? To the best of my knowledge, when pseudouridine was discovered in the 1950's, the known nucleotides were: A,C,T,G,U = five nucleotides. So why isn't pseudouridine the sixth nucleotide? Thanks 2A01:6500:A042:E52F:970A:37C0:5DE7:C30E (talk) 11:25, 21 May 2024 (UTC)

The original paper seems to be the 1956 publication doi:10.1016/S0021-9258(18)70770-9 which, in Table 1, shows they only considered A,G,C and U as known in RNA at that time. Mike Turnbull (talk) 15:22, 21 May 2024 (UTC)

May 22

Evidence of physical empath

I have been looking for a reference for studies to find evidence of a physical empath, meaning a person who experiences physican pain that those around him or her are experiencing. I can find a plethora of web pages claiming empathy is real. I'm not looking for silly web pages. I'm trying to find scientific studies. So far, I only found ones about emotional empathy, not physical empathy. 75.136.148.8 (talk) 18:29, 22 May 2024 (UTC)

Here's something:

• Armstrong, Kim (29 December 2017). "'I Feel Your Pain': The Neuroscience of Empathy". APS Observer. Association for Psychological Science.
• Riess, Helen (June 2017). "The Science of Empathy". Journal of Patient Experience. 4 (2): 74–77. doi:10.1177/2374373517699267.

Unsure, however, if that satisfies your perception of "evidence of a physical empath". The neuroscience of empathy shows that observing others in pain can activate similar neural networks involved in experiencing pain firsthand.

See also: Mirror-touch synesthesia --136.54.106.120 (talk) 23:19, 22 May 2024 (UTC)

Why does the northern hemisphere have two subtropical jets?

There are normally two subtropical jet streams in the winter northern hemisphere (e.g Fig12), one over Africa-Asia-North Pacific and the other over North America-North Atlantic. Why is that so? Maybe the cold Sahara/Canary Current and California Current yield the gaps? JoJo Eumerus mobile (main talk) 18:55, 22 May 2024 (UTC)

Where do you see two subtropical jets? One of them is subtropical jet and the second is polar jet. Ruslik_Zero 19:13, 22 May 2024 (UTC)

May 23

Inner space

What is outer space "outer" of? Is it "the region beyond Earth's sky" (i.e. the atmosphere) mentioned in outer space#terminology? I tried visiting Inner space, but it's a disambiguation page with no relevant results. Nyttend (talk) 02:14, 23 May 2024 (UTC)

There isn't a firm boundary for outer space, as atmospheric pressure exponentially decreases with altitude above Earth's surface (see scale height) and thus the exosphere blends into space rather than suddenly vanishing into a vacuum. The lead section of outer space gives at least one boundary defined by convention, and the body states that the density of atmospheric gas gradually decreases with distance from the object until it becomes indistinguishable from outer space; this need not occur at a fixed altitude even if we assume a constant pressure for the interplanetary medium (or threshold above it). I guess we could then say that outer space is "outer" to the region with a significantly higher density/pressure with respect to the interplanetary medium, or more simply, "outer" to any measurable atmosphere of a planet.

I've also never heard the term "inner space" in the context of planetary science. ^Complex/_Rational 02:38, 23 May 2024 (UTC)