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July 10

Surviving a firenado

Could a person survive getting sucked into a “firenado”? The question was inspired when I watch Into the Storm where a man got sucked into a firenado and die. Planet Star 00:40, 10 July 2018 (UTC)[reply]

Responders who want to tackle this one might want to peruse Into the Storm (2014 film) and Fire whirl. People occasionally survive all manner of seemingly unsurvivable events, but I'd think that being drawn into a tornado of essentially turbocharged gasses burning at 1,000°C would be quite hard to survive, as even if the victim was thrown clear quite quickly, a breath or two would likely cause fatal lung damage. I haven't myself been able to find any authoritative references specific to 'firenadoes', however. {The poster formerly known as 87.81.230.195} 90.212.98.167 (talk) 02:11, 10 July 2018 (UTC)[reply]

Why are the Great Plains of North America not considered to be a system of piedmont plateaus?

Or thought of as one.... A plateau is a high plain. Piedmont plateaus are plateaus that are bordered on one side by mountains and on the other by a body of water or a plain as is the case with the Piedmont Plateau east of the Appalachian mountains and west of the Atlantic Plain, and the Appalachian Plateau on the west of these mountains and east of the Central Plains. That all sounds like the Great Plains. The high plains of the Great Plains are west of the lower Central Plains and east of the Rocky Mountains. The Great Plains reach heights higher than 6000 ft above sea level in some areas. For example, Colorado Springs is around 6035 ft above sea level and Cheyenne, Wyoming is around 6062 ft in elevation. The Continental Divide is around 11000 ft in elevation, but the peaks of the Rocky Mountains can reach above 13000 to 14000 ft in elevation. One can see the the land rising as one approaches the Great Plains in some areas. What characteristics do the Great Plains lack from a piedmont plateau or is it actually a system of piedmont plateaus? Willminator (talk) 03:35, 10 July 2018 (UTC)[reply]

Have you read Great Plains? ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:54, 10 July 2018 (UTC)[reply]

It may be true that you can see the land rising as you approach them in some places but the part I crossed was very flat. It's a mile high drop but hundreds of miles wide and some elevation ranges of that mile are surely steeper than others. The Plains are ~~mostly volcanic ash deposits from the Rocky Mountains erupting since before the range was the height of the Himalayas or Andes, the further east the less ash and the closer to sea level.~~ Sagittarian Milky Way (talk) 05:30, 10 July 2018 (UTC)[reply]

"Mostly volcanic ash..."? That isn't how I learned my geology. The U.S. Geological Survey summary of the interior plains describes a great inland sea from which sediments accumulated and compressed.

Nimur (talk) 11:35, 10 July 2018 (UTC)[reply]

Huh, you are correct. How far west did the sea ever get? Sagittarian Milky Way (talk) 12:57, 10 July 2018 (UTC)[reply]

Well, that's a complicated question because over geological time-scales, the continents have moved and changed shape. For a start, here's the Wikipedia entry on the geologic timeline of Western North America and the main article on the geology of North America. If we go far back into ancient paleo-history, the areas that are now the great plains were underneath the western ocean abutting the continent of Laurentia; the far west parts of our continent (like California's Sierra Nevada mountains) didn't exist yet because the Nevadan orogeny didn't occur until the late Jurassic era... but this is all a vast simplification. Like all questions of science - how many years do we want to spend on the topic to refine and perfect our understanding?

When I used to teach geology for small kids, we gave a brief summary suitable for early elementary school: you can find fossils of seashells in the mountains of Colorado and Utah because a lot of that land used to be the bottom of the ocean. Once again, we're so severely oversimplifying that we run the risk of lie to children-style factual error.

A great book, for the interested reader: The Geology of North America: An Overview (1989); available at Amazon. One reviewer wrote, "...very dense and pretty dry..." Well, what can one expect from a book on rocks?!

If we want to get very precise about the exact farthest west extent, and so on, all I can say is that I am reminded of our discussion in March, quibbling on the details about the exact age of Earth. How shall we measure west-ness in paleo-Earth? Should we measure degrees of longitude, from the Greenwich meridian to the easternmost tidal high water mark? ... and where exactly was Greenwich, so many million years ago? These are, ultimately, issues that relate to false precision. Paleo-geology is a different kind of science than analytical chemistry; geologists have to accept an amount of intrinsic uncertainty; and so we accept that we must maintain the scientific method without any ability to conduct controlled experiment. But at the same time, we can hold ourselves to the highest standards of analytical investigative rigor.

Nimur (talk) 14:53, 10 July 2018 (UTC)[reply]

So in the case of the Great Plains, it matters how steep and long the slopes are from a plain or sea to the top of a piedmont plateau in order for it to be classified as a piedmont plateau and not just a high plain? Willminator (talk) 14:42, 10 July 2018 (UTC)[reply]

The U.S. Geological Survey's scheme for classification is centered around the idea of a "geological province," which is a concept they invented to group areas that have similar geological histories (and therefore, similar geological properties). But they use terminology fluidly: a region has specific areas that "exhibit the geology of the interior plains," even if there are counter-examples.

The term "piedmont" is used to refer to a specific, different area of the United States. In that sense, which is the canonical usage defined by the USGS, the word "Piedmont" is used as a locale, not as a generic description. For more information on this standardization of terminology, Wikipedia has an article on United States physiographic regions.

Nimur (talk) 14:53, 10 July 2018 (UTC)[reply]

I think the key thing that makes a plateau a plateau is that you can look up at it. According to the article, it is "raised significantly above the surrounding area". In the case of the Piedmont Plateau, there is an edge called the Atlantic Seaboard fall line. Though it's an obscure feature now, apparently at one point it meant a bunch of sweaty guys had to lug a canoe a long distance uphill practically any way they tried to boat inland, so it counted as a highly noticeable feature to them. The Great Plains don't have this AFAIK. Wnt (talk) 16:12, 10 July 2018 (UTC)[reply]

The Atlantic Fall Line can be quite dramatic in places and there's a clear delineation, for example, between the Atlantic Coastal Plain and the Piedmont all up and down the East Coast, from the Metacomet Ridge in Connecticut to the The Palisades in New Jersey. If you've ever crossed the George Washington Bridge, you're basically staring at the escarpment that marks the Eastern edge of the Piedmont. I live in Raleigh, NC which lies right on the fall line, and it's obvious when you're approaching it: South and East of Raleigh is flat: there's very little hills or elevation changes. In Raleigh, there are some fairly dramatic elevation changes in the area of the North Hills and the Crabtree Valley which clearly mark the transition to the Piedmont. There's also an even more dramatic transition from the Piedmont to the Appalachians, the Blue Ridge Escarpment, which you notice dramatically on any highway going west through the Carolinas or Virginia. By contrast, when traveling West across the Great Plains, there's no dramatic escarpments or changes in elevation. It's true that the great plains can get quite high as elevation gradually ramps up from East to West, but there's no clear boundary the way there is for the Piedmont.--Jayron 32 23:47, 10 July 2018 (UTC)[reply]

Here's the Palisades. There's still ridges of ancient metamorphic rock east of them, only about half the height of the Palisades at the GWB though. Beyond West Bronx and the skyscraper district with the tallest non-Manhattan building there's still naked eye hills over 200 feet above sea level but they're just piles of glacial detritus like terminal moraines. Sagittarian Milky Way (talk) 02:57, 11 July 2018 (UTC)[reply]

High index lenses

Are there any disadvantages to a 1.74 high index lens compared to one of lower index such as 1.67? I.e. Why doesn’t everyone with strong prescriptions get 1.74 instead of 1.67? Clover345 (talk) 07:52, 10 July 2018 (UTC)[reply]

Cost. Tigraan^{Click here to contact me} 09:54, 10 July 2018 (UTC)[reply]

Agreed. I have terribly myopic eyesight and shell out the extra for the high index lenses. When it comes time to pick out lenses, my optician and I typically have to sift through several pages of various strengths and coatings to get some reasonable trade-off between price and utility (fashion falling a distant third). People requiring the higher index lenses also typically require other modifications as well, driving up the price again. For example, my optician makes several modifications to the grinding of the edges to reduce glare simply because there's more lens there to cause it. Matt Deres (talk) 12:20, 10 July 2018 (UTC)[reply]

I have one of each. My eyes are strongly asymmetrical and although my prescription for one eye is strong enough to justify high index lenses anyway, I get a more mechanically balanced pair of lenses if the thicker lens is made thinner, but not the thinner one, so they end up matching more closely. It also has an effect on opacity for sunglasses.

Of course, graded index lenses would be even more interesting. Andy Dingley (talk) 13:28, 10 July 2018 (UTC)[reply]

While cost is a big factor, it isn't the only disadvantage. Coatings was mentioned above, but not clearly mentioned is one reason for coatings is because of the lenses. Higher index lenses generally mean more reflections, hence why nearly all high index lenses come with AR coatings. (And that can lead to other things like scratch resistance.) This is mentioned in the above linked source about cost but is also discussed here [1]. As mentioned there you also tend to get more chromatic aberrations, or other distortions of peripheral vision with high index lenses. (Also mentioned here [2] [3].) Although as mentioned, this tends to be a bigger problem for those with low powered prescriptions because those with higher powered ones are often more used to limitations of their peripheral vision. As sort of hinted there and also mentioned above, it also depends on the skills of the optometrist or whoever is designing the glasses/dispensing the prescription, along with choosing the best option, working with the patient. See e.g. [4] [5]. As mentioned in a the second source, a notable advance is using computerised tools to give a more precise individualised solution generally called digital, HD or free-form lenses [6] [7]. Nil Einne (talk) 15:47, 10 July 2018 (UTC)[reply]

How do Voltage converters deal with Hz?

Do voltage converters from 220/240 to 110/120 or from 110/120 to 220/240, normally also convert the between 50 and 60 Hz? I know most devices won't need a converter anymore and that this might be indifferent for most appliances, but sometimes it matters. --Doroletho (talk) 18:34, 10 July 2018 (UTC)[reply]

No. It's rarely necessary to do this. When it is, it's usually easier to replace the 60Hz motor with a 50Hz one (it's almost never necessary to do it the other way). For US machine tools imported to Europe, it's sometimes necessary to do this because poorly designed motors overheat on 50Hz as their design was marginal in the first place. Andy Dingley (talk) 20:30, 10 July 2018 (UTC)[reply]

And besides motors, are other devices affected by the 'wrong' Hz? Some devices set their internal clock through the electric power. Wouldn't these be heavily affected, specially if they run on a timer and require exact running times? --Doroletho (talk) 21:12, 10 July 2018 (UTC)[reply]

A timer or synchronous clock doesn't just require conversion, it needs accurate conversion. Such a thing is possible, but I've never seen anyone bother to do it. We do already have clocks in Europe - it's cheaper to just use a local one. Andy Dingley (talk) 21:19, 10 July 2018 (UTC)[reply]

Some clocks do use grid frequency to synchronize (at least in Europe). Of course, a 50/60Hz mismatch would make the clock completely useless, not "slightly missing on the precise time". Tigraan^{Click here to contact me} 08:57, 11 July 2018 (UTC)[reply]

Another device that the frequency affects is a transformer, though 50 and 60 Hz are close enough that I don't think it's likely to matter. See Transformer#Effect of frequency. --76.69.47.228 (talk) 09:40, 11 July 2018 (UTC)[reply]

Not true. A transformer designed for 50 Hz will run well at 60, but a 60 Hz transformer may overheat when run at 50. Akld guy (talk) 22:05, 14 July 2018 (UTC)[reply]

Most converters don't change the frequency. It is possible to get "inverters" or "frequency converters" that do this, though even the cheap ones are generally hundreds of dollars. Most electronics don't care about the frequency very much, and of those that do (e.g. things with motors or cheap timing circuits), it is often easier/cheaper to buy a version that is designed for the local frequency than it is to import a foreign version and buy an inverter. Dragons flight (talk) 08:20, 11 July 2018 (UTC)[reply]

July 11

copper pitchers for storing drinking water

The alleged beneficent results of drinking water stored in copper pitchers have caused great demand for them and they are selling hot on Amazon India and other online stores. Numerous sites display pages describing such benefits. Are there chances of copper poisoning from drinking water stored in a copper pitcher? — Preceding unsigned comment added by 2405:204:D00C:7689:5D99:8D01:C88E:2E5D (talk) 16:28, 11 July 2018 (UTC)[reply]

This study says that storing drinking water in copper vessels has clear benefits in killing off bacteria in the water and that "Safety of leached copper does not appear to be an issue since studies have shown that the current WHO guideline of 2 mg Cu/L is safe ...., and the levels leached in the study were 1/20th of the permissible limits." Mikenorton (talk) 16:38, 11 July 2018 (UTC)[reply]

It's noted in hospitals the spread of infection has greatly increased after copper worktops (which killed bacteria) were replaced by plastic ones. 46.208.78.215 (talk) 18:41, 11 July 2018 (UTC)[reply]

Who says so? ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:45, 11 July 2018 (UTC)[reply]

I don't know about any historic changes but Antimicrobial copper-alloy touch surfaces mentions clinical trials on new products. BTW we also have articles on Antimicrobial properties of copper and Copper alloys in aquaculture. Nil Einne (talk) 19:03, 11 July 2018 (UTC)[reply]

Copper is a poor choice, as it has toxicity risks. Although it also has antibacterial benefits, these are shared equally well (possibly better) by brass or monel fittings, which avoid the risks.

Copper is a risk depending on the water inside it. Hard water is fine, but something more acidic is a risk. Some contents - such as vinegar, pickles etc. involving acetic or lactic acid are downright dangerous. Andy Dingley (talk) 19:36, 11 July 2018 (UTC)[reply]

The above two articles for touch surfaces (which focuses a lot on in healthcare settings) and aquaculture at first glance seem to mostly deal with alloys given the titles.

However if you check the touch surfaces one, sometimes it simply refers to copper. Most of the time it's unclear if this specifically means near pure copper or just a simplification of copper containing alloys. However they do mention C11000 foil which seems to be basically a form of pure copper (see Oxygen-free copper, [8] [9] although note as mentioned in those sources silver is counted as copper) is used for cladding bed rails in one hospital. The EPA also has a group which seems to cover pure copper group I 95.2% to 99.99% 82012-1 although of course it doesn't necessarily mean these products are used in hospitals. Note that from reading all these sources, it seems one complication is probably that from what I've seen in the earlier articles, is what you count as an alloy e.g. C11000 may be called a copper-alloy although from what I understand as said earlier it's basically pure copper. (While you don't have to have much of something else to reasonably be called an alloy e.g. steel, from the earlier sources it seems like C11000 often does not intentionally include anything else. In other words, other components are impurities rather than add to make an alloy.)

Anyway point being, while the reasons for the various choices isn't really mentioned at least with some healthcare surfaces I'm not sure whether it's true that copper alloys are always definitely better than what may reasonable be called copper. (And I'm also not convinced that the reason for choosing an alloy rather than simple copper is because of toxicity concerns.)

BTW that earlier article for touch surfaces mentions brass. However it does not mention monel and at least for EPA approved surfaces, it seems monel isn't suitable or at least hasn't yet been demonstrated as it says all of the registered ones have over 60% copper. They do have other Cupronickel alloys with a significantly higher percentage of copper e.g. C70600 [10] is one mentioned for the same hospital mentioned earlier.

Nil Einne (talk) 04:28, 12 July 2018 (UTC)[reply]

Here in Australia there has been some recent media hype about old "copper" plumbing fittings actually containing some lead, and hence being a potential source of lead poisoning. Being slightly technical, this is an area where I don't trust journalists in the mass media at the best of times. Most have no scientific training. But it struck me as possible. HiLo48 (talk) 23:44, 11 July 2018 (UTC)[reply]

The lead is more likely to come from the solder used to join the pipes. Make sure the water container is not soldered with lead containing solder. Graeme Bartlett (talk) 00:50, 12 July 2018 (UTC)[reply]

For greater clarity: read "lead-containing solder" or "solder containing lead". --76.69.47.228 (talk) 10:03, 12 July 2018 (UTC)[reply]

Ah yes, old solder. That makes sense. HiLo48 (talk) 07:54, 12 July 2018 (UTC)[reply]

European practice for some years now is that soldered joints for potable water need to be made with lead-free solder.

There's still plenty of short stubs of lead pipe around in old houses, usually the main water supply into the house. In most water conditions, this isn't a problem (the pipe interior is coated with a layer of deposited minerals). In places where the water will corrode the lead, more of such pipes have been replaced by now. To connect modern piping to old lead it's necessary to use a mechanical pipe fitting, not a soldered joint. The specific type of soldered joint used to connect to old lead requires a leaded solder, so can no longer be used on potable water (by the regulations), even though it's still permissible to leave the old lead pipe in use. Andy Dingley (talk) 10:03, 12 July 2018 (UTC)[reply]

Regulations will vary widely around the world. The OP is presumably in India. HiLo48 (talk) 10:06, 12 July 2018 (UTC)[reply]

Metallic copper probably has little or no toxicity. It's the copper salts, such as copper sulfate, that are toxic. But you'd need to ingest about 10 to 20 grams copper sulfate in order to die. Copper sulfate ingestion is relatively popular for committing suicide in India. Acidic foods such as vinegar, pickles etc. are already preserved by the acid, so there's no further benefit from putting them into copper vessels. --46.189.28.77 (talk) —Preceding undated comment added 10:32, 12 July 2018 (UTC)[reply]

Wilson's disease is an inherited genetic disorder in about 1 in 30,000 people in which copper builds up in the body, named after neurologist Samuel Alexander Kinnier Wilson 1878 - 1937. Some of the signs of copper sulphate poisoning after swallowing 1-12 grams include a metallic taste in the mouth, burning pain in the chest and abdomen, intense nausea, vomiting, diarrhea, headache, sweating, shock and discontinued urination leading to yellowing of the skin. DroneB (talk) 14:57, 12 July 2018 (UTC)[reply]

Doctors that refuse abortions

is there a name for a doctor who refuses to perform an abortion (in a country where abortion is legal), based on personal beliefs? The source I have checked calls it a "Conscientious objector", but I'm not sure if we should use that term in Wikipedia's voice, as it seems to be specific to the military. The source probably uses it simply because it conveys a similar idea.

NOTE: I'm not asking for help or medical advise about abortions, just a name. I'm writing an article about a proposed abortion law, and I want to make sure that I'm using the right terms. Cambalachero (talk) 19:07, 11 July 2018 (UTC)[reply]

Maybe see Hippocratic Oath. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:37, 11 July 2018 (UTC)[reply]

"Conscientious objection" does appear to be the commonly used term. Searching google for "Conscientious objection abortion" finds many relevant hits.-gadfium 20:07, 11 July 2018 (UTC)[reply]

"Conscientious objection" is the term used in the Abortion Act 1967, Section 4. See also [11], [12]. --46.189.28.77 (talk) 20:14, 11 July 2018 (UTC)[reply]

And it's the term used by newspapers like The Guardian, but others refers to them as "abortion refuseniks" like The Spektator which is a misnomer, since refuseniks were the object of a denial, and not denied something actively themselves. --Doroletho (talk) 21:21, 11 July 2018 (UTC)[reply]

Perhaps we should update the article on Conscientious objector then, to include the non-military usage? Cambalachero (talk) 12:08, 12 July 2018 (UTC)[reply]

See Talk:Conscientious objector #Limited definition for previous discussion. hydnjo (talk) 18:50, 12 July 2018 (UTC)[reply]

Japanese home appliances in a country split between a 50 Hz and 60 Hz power grid?

Japan, as a very rare exception (Brazil is another, don't know about others), has a power grid split between a 50 Hz and a 60 Hz area. Are there home appliances versions for each area? Are home appliances designed upfront with the idea in mind that they might be used in one or the other area (and therefore made to be tolerant of deviations)?--Doroletho (talk) 21:35, 11 July 2018 (UTC)[reply]

Virtually all this list of home appliances, consumer electronics and AC adapters tolerate the difference between 50 Hz and 60 Hz mains frequency with only a minor exception of older electric clocks, tape recorders and record players that employ synchronous motors whose rotation period is an integral number of AC cycles. West Japan uses 60 Hz and east Japan uses 50 Hz; on the boundary between the regions there are back-to-back HVDC sustations that convert the frequency. DroneB (talk) 22:48, 11 July 2018 (UTC)[reply]

Note that some home appliances which are affected by mains frequency e.g. clock radios have a 50/60 Hz switch. These devices don't generally have synchronous motors of course and developing a product with one which can easily cope with both frequencies is I imagine difficult enough that it is basically very rarely if ever done. Nil Einne (talk) 04:35, 12 July 2018 (UTC)[reply]

The one device which both depended upon frequency and couldn't easily be changed was the synchronous motor. I've some industrial cam timer switches here which run on 50Hz, but they're designed for the US market too. As their motors are standardised, it's a two-screw operation to swap the motors. Motor makers for these just make them in two forms, with the same final speed. I've even got old (unusued) spares of 60Hz US motors for them, taken off US-built equipment and swapped over when it was imported. The motors run fine on 50Hz, they just run slow.

My woodworking machinery (the large fixed stuff) runs on induction motors, rather than the brushed universal motors that a smaller or cheaper power tool tends to use. These are also related to line speed, so my machines here run more slowly than they would in the US. These motors run at fixed speeds (either a nominal 1500 / 1800 rpm or 3000 / 3600 rpm, depending on their 4 pole vs. 2 pole design, and the 50Hz / 60Hz line frequency), so they often have a pulley and belt drive to change the speed to what suits the machine. If I wanted to, I could change the pulley by a small amount to bring the speed back to the original speed - but it's rarely needed. Andy Dingley (talk) 10:16, 12 July 2018 (UTC)[reply]

July 12

Glandular fever not found in a blood test, even though it's supposed to remain in the body for life

Somebody is saying that they had Infectious mononucleosis (glandular fever) and when they recovered, had a blood test and the virus was not found. But the glandular fever virus is supposed to remain in the body for life right? Is it possible a blood test wouldn't find it or some other explanation? — Preceding unsigned comment added by 2001:8000:1A4F:C500:2169:E3AB:DAE4:2459 (talk) 02:24, 12 July 2018 (UTC)[reply]

Depends on which test was done. As you can read further at Infectious_mononucleosis#Serology and its sources, most blood tests for Epstein-Barr are actually for the antibodies your body raises against the virus. Once it has been in the latent phase for a while, most of those antibodies become undetectable. There is also the possibility of a false-negative. Someguy1221 (talk) 02:57, 12 July 2018 (UTC)[reply]

In latency the virus is tightly controlled by the immune system and it is usually undetectable because it is present in the blood only in very low numbers. Ruslik_Zero 06:40, 12 July 2018 (UTC)[reply]

Spatial memory

What games (video games, traditional games, etc) are scientifically proven to enhance spatial memory? — Preceding unsigned comment added by 149.129.219.94 (talk) 07:14, 12 July 2018 (UTC)[reply]

"Playing “Tetris” on Nintendo DS develops the ability to imagine rotations of objects in 2D and 3D (spatial relations) to a greater extent than playing Tetris on a PC."

(PDF) Do Video Games Improve Spatial Abilities of Engineering Students?. Available from: [13]. See also: [14] Richerman (talk) 13:15, 12 July 2018 (UTC)[reply]

Rubik developed his cube to help students understand 3D rotations. Don't know if there's any studies on whether it helps though. Dmcq (talk) 15:31, 12 July 2018 (UTC)[reply]

July 13

Millipede legs; restriction on total number

Centipedes always have an odd number of pairs of legs, meaning that their number of legs is always divisible by 2 but not by 4. But is there any restriction on how many legs a millipede can have?? Georgia guy (talk) 00:49, 13 July 2018 (UTC)[reply]

This article,[15] among others, says millipedes have four legs per segment. ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:18, 13 July 2018 (UTC)[reply]

Which means that millipedes could never have the same number of legs as centipedes. --Jayron 32 00:16, 14 July 2018 (UTC)[reply]

One Internet site talks about 394 as a common number of legs; another says that millipedes always have an even number of pairs (meaning a number that is divisible by 4.) These 2 sources clearly contradict each other. Georgia guy (talk) 00:22, 14 July 2018 (UTC)[reply]

Sometimes a source won't have a leg to stand on. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:33, 14 July 2018 (UTC)[reply]

Encyclopedia of the Animal World, Elsevier 1972, calls the segments "rings" and says that most rings have 2 pairs of legs, while the first few rings only have 1 pair of legs. So it looks like the number of millipede legs could be divisible by four or two, depending on whether the number of segments with 1 pair of legs is even or odd.--Wikimedes (talk) 16:46, 14 July 2018 (UTC)[reply]

Discounting "common species have between 34 and 400 legs" in our millipede article, I haven't found a specific example of a millipede with the number of legs divisible by 4. From the 2nd paragraph of Millipede#Body: "The second, third, and fourth body segments bear a single pair of legs each and are known as "haplosegments"", which would indicate that the number of legs is never divisible by four. This [16] site says there are "often 3" haplosegments.--Wikimedes (talk) 17:18, 14 July 2018 (UTC)[reply]

And again I know nothing about birds

So, saw these little guys while boating. Didn’t see any larger birds that looked like adults of the same species. This was right on the waterline of a small island in a freshwater lake in the Kenai National Wildlife Refuge. They certainly acted like chicks, making little “cheep cheep” noises, staying right on the apparent nesting site, making no attempt to fly or swim. Anyone know what they might be? Beeblebrox (talk) 02:30, 13 July 2018 (UTC)[reply]

I certainly know nothing about birds too, but they look a bit like greater sage-grouse chicks to me. Alex Shih (talk) 02:46, 13 July 2018 (UTC)[reply]

Here is a website for Alaskan birds. Of course it is a big state with lots of avians so it might take some searching. To my untrained eye this is a bit like your pic - especially if you allow for variation in coloring for young chicks. I could be way off though. MarnetteD|Talk 04:30, 13 July 2018 (UTC)[reply]

Rats I missed where it stated that the turnstone is a coastal bird. Good luck in tracking it down. MarnetteD|Talk 04:33, 13 July 2018 (UTC)[reply]

The beaks are too substantial for turnstones, they're probably some kind of young gulls, which are notoriously hard to identify. Acroterion (talk) 00:36, 14 July 2018 (UTC)[reply]

The fact that this is a freshwater lake may narrow the field. I’m beginning to think they are maybe Arctic Terns. Most images I can find show a orangish-yellow beak, but some of juveniles show a duller beak as these have. Beeblebrox (talk) 17:19, 15 July 2018 (UTC)[reply]

Vitamin B11

I can't find the chemical formula for Vitamin B11 (pteryl-hepta-glutamic acid). Can you help? 121.44.187.6 (talk) 03:57, 13 July 2018 (UTC)[reply]

There isn't one in this list B vitamins#List of B vitamins. Hopefully someone else can help. MarnetteD|Talk 04:22, 13 July 2018 (UTC)[reply]

A google search bring up this. MarnetteD|Talk 04:24, 13 July 2018 (UTC)[reply]

BTW, although it's one of the few to be unsourced I'm fairly sure our article is right. There's no longer such a thing as a recognised Vitamin B11 in humans. Any source which still calls pteryl-hepta-glutamic acid (or PHGA or chick growth factor) as a human vitamin B11, or which says there is such a thing as a human vitamin B11, is either outdated or unreliable. Or maybe both. If someone is trying to sell you something with vitamin B11 for human consumption, run away. Nil Einne (talk) 08:46, 13 July 2018 (UTC) 09:53, 13 July 2018 (UTC)[reply]

This is the original poster. I am well aware it has no value for humans. It happens that I am in a family of chicken ranchers. 121.44.187.228 (talk) 08:53, 13 July 2018 (UTC)[reply]

This one was a head-scratcher. The problem is that references to Vitamin B11 basically end in the 1950s as far as the scientific literature goes (though the papers that studied it continue to be cited later). Many of the papers on the subject are behind paywalls even my library can't get past, and those that I can read predate the chemical identification of the molecule. The first clue I had that something was wayyy off was seeing articles much much later that cited these B11 papers while discussing folic acid! Indeed, NCBI's pubchem lists "vitamin B11" as one of the 200+ synonyms for folic acid[17]. Unfortunately, it's specifically listed in vendor synonyms. Which means, at some ponit, somewhere, folic acid has been sold as B11. Which does not mean that scientists consider it the same. Anyway, what I conclude, but can't be 100% sure of, is that it was identified as an essential vitamin for chicks, and later found to be a known compound, and the name was never used again. Someguy1221 (talk) 10:32, 13 July 2018 (UTC)[reply]

I did discover that some naturopaths & homeopaths sell what they call "Vitamin B11" as folate. What they are actually selling could be anything - particularly homeopaths, homeopathy being essentially 100% quackery, and B11 being useless for humans as noted. Can any nice chemist tell me how to arrive at a formula for pteryl-hepta-glutamic acid? OP 121.44.185.44 (talk) 13:55, 13 July 2018 (UTC)[reply]

It does apear to be a folate derivative. Here's a ref (I don't have time to chase the cited refs right now): doi:10.1021/jo00837a600. DMacks (talk) 14:15, 13 July 2018 (UTC)[reply]

Here's another one. Ok, so part of the problem was that it's actually pteroylhepta-γ-L-glutamic acid. Also explains the history. When people started purifying folic acid and identifying its chemical structure around the 1940s, it was found that there were many forms, some of which only differed in the length of the glutamate chain (as a name of a chemical rather than a class of chemicals, "folic acid" only has one glutamate). It was further found that the length of the glutamate chain affected the molecules bioavailability in a species-specific manner. That's it. That's all, nothing else magical or special. Different organisms like to get their folate while it's attached to different things. Someguy1221 (talk) 00:09, 14 July 2018 (UTC)[reply]

The article you found gave me exactly what I needed. Many thanks for your help. OP 118.209.58.129 (talk) 13:49, 16 July 2018 (UTC)[reply]

July 14

Mass of earth over time

This article discussing a meteorite impact 3 Ga ago claims that "when this asteroid hit, Earth was only a third its current size". I've interpreted that as meaning that the earth was 1/3 of it's current mass at that time, which I find very, very hard to believe. An alternative interpretation is not occurring to me either. I've been trying to find something like a graph of the mass of earth over time, but I can't find such a thing. I imagine it's because the mass of the earth only substantially changed in the period up to and during the formation of the moon (4.5 Ga ago), and that since then changes to the earth's total mass have been negligible. The late heavy bombardment (4.1 to 3.8 Ga ago) consisted of around 22,000 objects large enough to leave craters at least 20km in diameter on earth. Even if we assume all 22,000 of them were the size of 5 Astraea (which would leave a crater far larger than only 20km in diameter) and no ejecta escapes the earth's gravity, the event only would have increased the earth's mass by around 1%. Since the LHB, I don't think there have been any major sources of additional mass, and the slow accretion of additional mass which is negligible anyway has been opposed by the gradual loss of hydrogen and helium. Is there any possibility that the claim in this article is correct? Also, does anyone know if a graph of the estimated mass of the earth over time, even if it just covers the accretion and moon formation stages exists anywhere? 2A0D:5600:3:9:201:200:0:10B3 (talk) 08:26, 14 July 2018 (UTC)[reply]

Yeah, that's nonsense. I suspect what someone intended to say was that at 3 Ga, the earth was 1/3 it's present age, but somehow that got miscommunicated as "size". Dragons flight (talk) 08:34, 14 July 2018 (UTC)[reply]

(EC) Several of the comments under the article say that this should read "a third its current age". That is numerically correct, and presumably also what the author intended to write. If Earth had indeed tripled in size by whatever process, there would be no way that any traces of this crater would be detectable now. --Wrongfilter (talk) 08:36, 14 July 2018 (UTC)[reply]

(ECx2) Yeah I was right about to post the same, after "lulwhat?" I did check the the original paper to make sure, and no, it doesn't make this statement anywhere. Someguy1221 (talk) 08:36, 14 July 2018 (UTC)[reply]

Pfft. This is clearly a clever set-up for a geologically based "Yo mama..." joke. Matt Deres (talk) 02:49, 15 July 2018 (UTC) [reply]

See, they just admitted expanding Earth is true! Wake up sheeple! --47.146.63.87 (talk) 07:52, 15 July 2018 (UTC)[reply]

Note that Earth gains mass from meteors and loses mass from gasses stripped by solar wind and by radioactive decay -- at nearly identical rates [18] (estimates vary). —2606:A000:1126:4CA:0:98F2:CFF6:1782 (talk) 18:04, 15 July 2018 (UTC)[reply]

July 15

Photography - tracking fast moving subjects

In professional filmmaking, how are cameras stabilised when they are following a fast moving subject close up? For example of an actor is sprinting and the cameras is right next to them following, how is the camera stabilised? Assuming that it’s not possible to use a guide rail. Let’s say the actor is sprinting over many obstacles and turning a lot and the filming is done in a public area. — Preceding unsigned comment added by 90.206.71.55 (talk) 12:15, 15 July 2018 (UTC)[reply]

Wildlife photographer Roger N. Clark explains The key to fast autofocus and focus tracking is the use of phase detection focus. The link shows examples. DroneB (talk) 12:55, 15 July 2018 (UTC)[reply]

SteadiCam, and many similar products, provide smooth video of motion using mechanical stabilization and a trained operator. Nimur (talk) 14:43, 15 July 2018 (UTC)[reply]

Steadicam's introduction was apparently a really big deal. I came across this recently and there's a couple interesting historical pages from the current manufacturer.[19][20] The "art museum steps" scene from Rocky was inspired by a very similar shot in the original Steadicam demo reel. The full sized ones (made for Hollywood movie cameras) are huge and expensive but they now have some small handheld ones for smartphone/gopro sized cameras that are pretty affordable I do not need another gadget.... Interestingly only a very recent (phone sized) model has a gyroscope: I had expected they all did, but apparently the traditional one is just an elastic mount on some gimbals, completely inertial. 173.228.123.166 (talk) 16:54, 15 July 2018 (UTC)[reply]

Also there is a Hollywood profession of focus puller, someone whose sole duty is to focus the lens while the shot is in progress. That is not so easy to do automatically. The focus puller has to understand exactly how stuff will be moving in the shot and what parts are supposed to be kept in focus, so that the focus movements are pre-planned/choreographed but done in real time as the shot proceeds. 173.228.123.166 (talk) 16:58, 15 July 2018 (UTC)[reply]

A little web research shows bigger gyroscope stabilizers are a thing. ken-lab.com apparently originated them in the 1950s. There are other brands and some DIY ones now[21] (even one using old hard disk drives as gyros![22]) but it all seems cumbersome and low tech. I tried some stabilized binoculars in a store once (they have little piezo actuators that wiggle the prisms in the binocular to compensate for wobble) and they worked amazingly well, and optical image stabilization in camera lenses is similar, so I guess this gyro stuff is for heavier gear, higher amplitude vibration etc. 173.228.123.166 (talk) 19:16, 15 July 2018 (UTC)[reply]

Differences between hydrogen and most elements

Why do isotopes of hydrogen make such a big difference?? If all carbon on earth were C14 instead of the standard C12, it wouldn't affect life very much. But if all hydrogen on earth were H2 instead of the more common H1, we would die. Why do isotopes of hydrogen affect the element's behavior more strongly than isotopes of other elements?? Georgia guy (talk) 18:29, 15 July 2018 (UTC)[reply]

What are the bases of your two premises? ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:43, 15 July 2018 (UTC)[reply]

Bugs, this is kind of a well-known fact, except that the choice of C14 is unfortunate. C14 is very radioactive, with a half-life of only 6K years or so. If all carbon on Earth were C14, we would die promptly from radiation poisoning. But from a chemical point of view, I think GG is correct (the choice of C13 instead of C14 would probably have made the question correct).

I think the answer is that the extra neutron just makes a lot more difference when there's only one nucleon to start with. For example deuterium has double the mass of ordinary hydrogen. That affects the energetics of chemical reactions. Someone who knows more about quantum chemistry can probably elaborate, but I think this is the main point. --Trovatore (talk) 18:53, 15 July 2018 (UTC)[reply]

I guess this is also to do with energetics of reactions, just not chemical ones...but since the mass will effect the average velocity of the particles in solution, it would also have an effect on rates of diffusion. 61.247.39.121 (talk) 23:09, 15 July 2018 (UTC)[reply]

That's the basis for the original separation of uranium isotopes during the Manhattan Project. --Khajidha (talk) 14:20, 17 July 2018 (UTC)[reply]

The Heavy water#Effect on biological systems says

The larger chemical isotope-effects seen between protium (light hydrogen) versus deuterium and tritium manifest because bond energies in chemistry are determined in quantum mechanics by equations in which the quantity of reduced mass of the nucleus and electrons appears. This quantity is altered in heavy-hydrogen compounds (of which deuterium oxide is the most common) more than for heavy-isotope substitution in other chemical elements.

BTW it also mentions the, I agree well known, problems organisms have with heavy water. It's perhaps worth remembering that while it's sometimes worth challenging a statement made in a question where you have good reason to be uncertain if it's true, it's not necessary to challenge every single statement made especially ones you know nothing about. If you just wish to know more about something said, it would be better to phrase it as a question. Nil Einne (talk) 19:55, 15 July 2018 (UTC)[reply]

Which is what I did. And Trovatore immediately shot down the first of the two premises. And thank you for providing a source for the second premise. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:14, 16 July 2018 (UTC)[reply]

No you did neither of what I said. Your response wasn't a polite question for more information but questioning a basic well known fact that frankly anyone who hangs out at the Science desk should already some inkling of. If you had just wanted more info on this basic fact, you should have wrote a polite question asking for it, rather than unnecessarily questioning such a basic fact. BTW, it sounds like you remain confused. Trovatore clarified that while the OP's specific example was flawed, but both of their basic premises were in fact correct. As now supported by the article I linked to. (Albeit which didn't seem to be directly sourced.) Nil Einne (talk) 08:18, 16 July 2018 (UTC)[reply]

"If all carbon on earth were C14 instead of the standard C12, it wouldn't affect life very much." Is that a true statement? ←Baseball Bugs ^{What's up, Doc?} carrots→ 15:59, 16 July 2018 (UTC)[reply]

No idea why you're asking something we've already established was incorrect. If you're understanding of this discussion is so limited, I strongly suggest you just stay away from the RD for good or at least as a responder. This isn't even a case of a limited English ability where we can allow reasonable latitude. Your English ability is clear up to the task, your ability to understand very simple discussions appears not to be. Nil Einne (talk) 10:52, 17 July 2018 (UTC)[reply]

For the benefit of nitpickers, I should clarify that this depends on the precise wording and how it's interpreted and there's a chance we don't know for sure the answer to the question. Assuming that the statement is interpreted to mean it's always been that way, then there's a reasonable chance life would be different. It's possible it would not have managed to evolve although I expect more likely it would have evolved to cope with C14. It seems likely this would mean significant differences. Even more so with organisms that live very long (thousands years or more for example). Of course a wider point is that the short half-life means a world with C14 is unlikely to be plausible, I don't see how your world could ever produce enough C14 to keep it the primary form of carbon, well unless we're thinking about tiny amounts. If it's simply a case that all the C12 was magically replaced with C14, it would seem likely as Trovatore said that life would not cope with this and most would die out. Mind you, I'm not sure that there's anything in heavy water (or the other molecules of life with hydrogen) that means most of life couldn't also work with heavy water. So if life evolved in a world where most hydrogen was predominantly deuterium, I suspect life would also have managed to make a go with it. (But this is just a guess, I know too little to have any confidence.) This is of course moot to the question, since as I already mentioned anyone with basic scientific understanding could interpret what was meant. As someone had wanted to nitpick these and any aspects, that seems reasonable (especially if the question has been answered). But I still see no benefit to anyone questioning a very basic and basically correct premise namely that life which has evolved to cope with hydrogen-1 cannot cope with deuterium, rather than either politely asking for an explanation for something a person may reasonably be unaware of, or just leaving the question be. Nil Einne (talk) 11:28, 17 July 2018 (UTC)[reply]

You're starting to catch on. Life could have evolved to tolerate C14 and/or deuterium. But it didn't. Not on earth, anyway. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:22, 17 July 2018 (UTC)[reply]

All C14 would be a lot of radiation. Low-energy betas, but still. I think there's a better chance life could have evolved to use deuterium than C14. --Trovatore (talk) 18:10, 17 July 2018 (UTC)[reply]

Rinsing out a vessel

You have a 1 litre vessel full of soapy water. You want to rinse it until 0% soap remains (or nearly 0%). Which is most efficient?

Pour out the soapy water. Fill it 10% full of clean water. Swish it around. Pour it out. Repeat until 0% soap remains.
Pour out the soapy water. Fill it 50% full of clean water. Swish it around. Pour it out. Repeat until 0% soap remains.
Pour out the soapy water. Fill it 90% full of clean water. Swish it around. Pour it out. Repeat until 0% soap remains.

Anna Frodesiak (talk) 20:44, 15 July 2018 (UTC)[reply]

Strictly OR, but when camping (with limited potable water), I use something most similar to 1 for washing dishes, etc. However, I too, would be interested in a "scientific" answer. 2606:A000:1126:4CA:0:98F2:CFF6:1782 (talk) 21:17, 15 July 2018 (UTC)[reply]

I think the answer is going to vary a lot depending on what sort of "efficiency" Anna has in mind, and a little bit on what "0%" means. Of course you're never going to get to literally zero percent by any practically feasible method. But if you have a threshold in mind, you can optimize the procedure for getting to that threshold based on things like the amount of time spent, the amount of water used, how difficult it is to "swish". I don't think we can really come up with a definitive answer here. --Trovatore (talk) 21:18, 15 July 2018 (UTC)[reply]

I assumed "efficient" meant least amount of water used (and "nearly 0%" meant undetectable for ordinary use). 2606:A000:1126:4CA:0:98F2:CFF6:1782 (talk) 21:36, 15 July 2018 (UTC)[reply]

I guess by efficient I mean time and effort. Anna Frodesiak (talk) 21:41, 15 July 2018 (UTC)[reply]

In that case, I'd go with 3 (more intuitive than scientific answer). 2606:A000:1126:4CA:0:98F2:CFF6:1782 (talk) 21:45, 15 July 2018 (UTC)[reply]

(ec) Too complicated for a once-and-for-all a priori solution, I think. We'd need to have a model that incorporated the rate at which the soap diffuses into the clean water, the characteristics of the pot as regards "swishing", et cetera. Probably best to just try it a few different ways and see what works for you. --Trovatore (talk) 21:48, 15 July 2018 (UTC)[reply]

If the contaminant is just soap, a few quick rinses with small amounts of water is easiest and saves water. Say dumping out the vessel's contents leaves 1 ml of solution in it by surface tension (probably too high a guess). If you started out with 1ml even of pure soap and treat the rinsing as pure mixing into a solution, 3 rinses of 100ml each would get to 1/100³ or 10^-6 concentration, same as 2 rinses of 1000ml each, but probably quicker. See homeopathic dilution if you want to get silly. 173.228.123.166 (talk) 23:43, 15 July 2018 (UTC)[reply]

That assumes that the soap mixes evenly with the water, in a reasonable time. It's not clear that that assumption is reasonable. In my experience, it tends to stick to the pot, at least some sorts of pot. --Trovatore (talk) 03:43, 16 July 2018 (UTC)[reply]

Can this be changed to a more pure example to come up with a maths or physics type answer? For example, 1% dye. Add water. Allow for mixing by osmosis, etc. Anna Frodesiak (talk) 04:15, 16 July 2018 (UTC)[reply]

Trovatore, yeah, soap dissolves more readily in hot water if that helps. Anna, let's say it takes a seconds to draw a liter of water from your faucet, so x liters (say x=0.1) takes ax seconds. Then you spend b seconds sloshing it around and dumping it out (this is presumed independent of x), and there's c liters (like 0.001 liters = 1ml) of solution left in the pot after you dump it. You started with 1% dye (let's say you dump it immediately so only c liters of 1% dye are left in the pot before you start rinsing), so after n rinses of x liters each, the amount of dye left will be 0.01⋅(c/x)ⁿ and the time spent will be n⋅(ax+b) seconds. Let's say you want to rinse til the dye concentration is 10^-6. If x=0.1 this takes 3 rinses and 0.3a+3b seconds, and if x=1 it takes 2 rinses and 2a+2b seconds. I guess it takes about 10 sec to get a liter of water from my kitchen sink, and maybe b=5 sec of sloshing. In that case, the 2x 1 liter rinse is 20+10=30 sec and the 3x 0.1 liter rinse is 3+15=18 sec.

I guess if the number of rinses turned out to be much higher (like if you wanted 10^-100 concentration, which is physically silly) or if you treat n as a continuous variable, you could frame this as an optimization problem where you solve for x to minimize the time spent. You'd draw a graph that would have some minimum, write out equations and find where the derivative is 0. But of course you probably would want more parameters in the model than just the water fill rate and slosh/dump time. Anyway this is the general approach to what I think you were asking. 173.228.123.166 (talk) 05:03, 16 July 2018 (UTC)[reply]

So, based on the above, is it better to use less water more times or more water fewer times? Anna Frodesiak (talk) 05:11, 16 July 2018 (UTC)[reply]

You still have an undefined goal of "better"/"efficient". Do you mean in terms of time? Number of actions (which may not be the same as "time" if you consider it takes longer to do something with a larger volume)? Total amount of water used? Is there no worry about evaporation or surface tension ("stickiness" of the soap to the surface)? Is the soap completely and quickly water-soluble (with no residue of relevance, and not difficult to rinse away)? If you are merely trying to get the lowest possible remainder, then there is no cost and a definite gain to using a larger amount of water in each rinse (though when a container becomes very full, it is harder to mix it evenly). And heck, may as well do it lots of times too (again, no cost). But if you are trying to conserve total water usage, then "many smaller batches" is generally more effective than "fewer larger batches" as long as each batch is large enough to mix well, not evaporate, and pour out easily (practical concerns of handling the material). DMacks (talk) 05:19, 16 July 2018 (UTC)[reply]

For clarity, the OP has already said "I guess by efficient I mean time and effort" which while maybe not completely clear, does seem to suggest water used isn't much of a concern in and of itself. BTW, I suspect there's also a reasonable chance it may depend on whether the container can be closed especially if we using an extreme like only talking about the amount of water used and not considering anything else. Nil Einne (talk) 08:22, 16 July 2018 (UTC)[reply]

Well, this is a standard math question in German schools (usually with only two fixed schemes given). Under the usual assumptions (spherical cows on a perfectly slippery surface in a vacuum, i.e. perfect mixture of rinsing water and soapy water, a fixed amount of liquid remaining in the vessel after each rinse, no evaporation or other funny effects, optimisation goal is minimal water usage) the solution in the limit is to do an infinite number of rinses with no water at all ;-). The less water you use for a given rinse, the higher the concentration of soap in the solution you pour out. So for a given amount of water you want it to go in in as small increments as possible. --Stephan Schulz (talk) 09:24, 16 July 2018 (UTC)[reply]

The reason why that works isn't mysterious, nor even mathematical. Suppose you have a vessel partly full of soapy water. Do you wash it out better by (a) mixing fresh water into the soap-water, or (b) throwing out as much of the soap-water as you can first? Clearly there can be no merit to contaminating the fresh water unnecessarily. Wnt (talk) 12:41, 16 July 2018 (UTC)[reply]

Anna re So, based on the above, is it better to use less water more times or more water fewer times?, if it's based purely on minimizing time, there will be an optimum. We had 30 seconds for 2 rinses with 1 liter, and 18 sec for 3 rinses with 0.1 liter. Let's consider 0.01 liter so with the same parameters you need 6 rinses. That would be 30.6 seconds, even worse than rinsing with 1 liter. If the number of rinses doesn't have to be an integer, then in this case the optimum would be about 0.129 liters for 2.84 rinses taking 17.88 seconds. That makes 0.1 liters very close to ideal. 173.228.123.166 (talk) 20:36, 16 July 2018 (UTC)[reply]

The OP posed the question with three techniques, each one starting with throwing out the soapy water. Thus each of the three starts with the pan in the same condition. She wants to end with zero soap in the pan, so each of the three ends with the pan in the same condition, whose degree of cleanliness is immaterial; it's the same state for each of the three techniques. She indicated that time and effort were her criteria. The three are fills of 10, 50, and 90 percent, swishing, and tipping out repetitively until zero soap is left. There are finite times involved: to fill to 90% will take nine times as long as for 10%. The effort of lifting will also be greater, but let us assume that this is not onerous and ignore it. The question then comes down to how much time is involved in filling versus how efficient the three different filling levels are, i.e. 10% will fill quicker from the tap but does it require more fills than 90% to achieve the same soap reduction? Kitchen experience tells me that 90% filling will dilute soap remnants much more than 10% will, but at the expense of taking longer to fill. Therefore I'd have to go with the mid-range figure of 50% as the best compromise of the OP's stated choices. There may be a more efficient filling of say, 25-30 percent, but the OP did not give that as an option. Akld guy (talk) 22:42, 16 July 2018 (UTC)[reply]

July 16

Fed wasabi peanuts to seagull

Yesterday, I threw a few of my wasabi coated peanuts to a seagull.

I was under the impression that birds couldn't taste spicy food, but obviously I was wrong in this case. The poor thing started shaking its head, running back and forth, scratching at its mouth and then vomited. Seems that wasabi does the same to gulls as it does to people who don't like it.

(didn't do it on purpose just to mess with it, I swear - it seemed okay afterwards and was eating the pieces of sandwich I threw out)

I've seen birds eating habaneros with no issues. I don't think it even affects them in the same way it does people. What's different about wasabi? — Preceding unsigned comment added by 91.207.175.200 (talk) 08:28, 16 July 2018 (UTC)[reply]

Have you never notices that the hit from chillis is completely different from that of wasabi (as for that matter, black pepper, Sichuan pepper and galic)? The 'heat' from chillis comes from Capsaicin. As mention in that article, it causes a burning sensation when it comes into contact with mucous membranes in mammals. The hit in wasabi, whether real wasabi or most of the stuff you get in the West (and I think even a lot in Japan), green coloured horseradish, comes primarily from Allyl isothiocyanate. (Also mustard and radish.) As mentioned in the wasabi article but not in the other articles, it primarily comes in the nasal passage in humans. And it isn't hydrophobic like capsaicin so is more easily removed with water where oils (including an emulsion like milk) is the best solution. While our article doesn't specifically mention the effect in birds, it does mention animals not mammals. And the places where it is present in plants as a defense mechanism against herbivores suggests the plant wouldn't want any animal who consumes it unaffected. (Although as our article on capsaicin sort of indicates, while it's advantageous to the plant that birds are unaffected by capsaicin, we can't be sure how much of a factor this was in its evolution.) Nil Einne (talk) 09:10, 16 July 2018 (UTC)[reply]

It may depend on the bird. Anecdotally, some parrots appear to enjoy eating wasabi (or at least things marketed as "wasabi"). Google for parrots and wasabi, and you can find examples of people giving them as treats to birds that apparently like them. I don't know if they are sensitive to the wasabi but eat it anyway, just like some people like spicy things, or if they just aren't sensitive to it. To give another anecdote from a different species, we were trying to train a young puppy to stop chewing on furniture, so we got a spray that is intended to taste/smell awful and deter them. We quickly found this particular spray was worthless because she would follow us around and lick it off anything we sprayed. I assume she was tasting something, but she clearly didn't perceive it as undesirable. Dragons flight (talk) 09:26, 16 July 2018 (UTC)[reply]

Some more research found [23] who found cloned chicken TRPA1 was activated by allyl isothiocyanate. Then again they also found it was activated by capsaicin. (There's some more research into how capsaicin affects chicken TRPA1 later which I didn't read in detail.) This is also looks interesting: I haven't looked at the paper [24], but the abstract suggests they found that one of the mechanism allyl isothiocyanate affects mammalian or at least mouse TRPV1 appears to be by binding to the capsaicin binding site and so this doesn't occur in chicken TRPV1. That said, this is fairly remote from the question. Maybe because my searches are too technical, I haven't found any source which actually mentions whether birds are known to show any response to allyl isothiocyanate. It's easily possible of course that the effect observed by the IP was not due to allyl isothiocyanate but due to something else. I'd also note it may depend on quantity, some of the sources I read make me wonder whether birds are really completely immune to capsaicin as commonly suggested or the effect is just a lot milder so you'd need a very strong dose for them to notice anything. Nil Einne (talk) 10:33, 16 July 2018 (UTC)[reply]

BTW on the evolutionary point I made above, I probably should also mention while there may be real evolutionary advantage for birds to be unaffected, there may also be little advantage for birds to be affected since I'm not sure if many are likely to eat the parts. Nil Einne (talk) 10:41, 16 July 2018 (UTC)[reply]

I suspect that the "parts" is really the key to understanding this. In chili peppers, the capsaicin concentrates in the fruit. This makes some evolutionary sense: mammals chew their food, especially plant-eaters, so seeds could well be crushed or damaged by them. It pays off for the plant to have mammals avoid them. On the other hand, birds tend to swallow stuff whole. So, peppers eaten by birds would be transported and deposited whole in the feces - exactly what the plant "wants". Quite an elegant solution. Wasabi, horse-radish, and radish are set up differently. In those cases, it is the stem/root with the concentrated toxins. Since it's almost never in the plant's favour to have this portion eaten or damaged, it makes sense that a more widely applicable material would be used. Matt Deres (talk) 16:29, 17 July 2018 (UTC)[reply]

Molecular term symbols and electronic configurations

I think that I've made some progress in learning to interpret molecular term symbols, given available molecular orbitals. Taking dicarbon, and it's first eight electronic states, I've determined the electronic configurations to be as follows:

X: [He
₂] 2σ²
_g2σ²
_u1π⁴
_u
a/A: [He
₂] 2σ²
_g2σ²
_u1π³
_u3σ¹
_g
b/B: [He
₂] 2σ²
_g2σ²
_u1π²
_u3σ²
_g
c: [He
₂] 2σ²
_g2σ¹
_u1π⁴
_u3σ¹
_g
d/C: [He
₂] 2σ²
_g2σ¹
_u1π³
_u3σ²
_g

I'm fairly sure that I've correctly determined the first five configurations, but I'm uncertain about the last two. Should I opt for a configuration where the 2σ
_u is fully occupied and the 1π
_g is not left empty? It just seems odd to me to have the lower orbitals partially occupied while the HOMOs are full. However, the configuration that matches my suggestion requires additional unpaired electrons that looks like it would be unfavourable, for it to retain the same term symbol.

d/C: [He
₂] 2σ²
_g2σ²
_u1π²
_u3σ¹
_g1π¹
_g

For reference, the term symbols can be found at https://webbook.nist.gov/cgi/cbook.cgi?ID=C12070154&Units=SI&Mask=1000#Diatomic. Also, are my first five determinations actually correct? Plasmic Physics (talk) 12:37, 16 July 2018 (UTC)[reply]

I have no idea, but let's put some links on the table for context: term symbol, dicarbon, Swan band, Molecular_term_symbol#Alternative_empirical_notation. This old paper gives a subjective sense of the energies involved (page 10) - the difference between their two bonding states is enough to leave the lower state's bond vibrating from 1.1 to 1.7 Angstroms in length! ... Wnt (talk) 18:26, 16 July 2018 (UTC)[reply]

That should really be renamed 'Supplementary empirical notation', as it is used in conjunction with term symbols, not in place of. Plasmic Physics (talk) 22:36, 16 July 2018 (UTC)[reply]

Note that a and A are not the same. the lower case sequence is in the triplet state, with two electron spins the same, whereas the capital sequence have the singlet state, spins opposite. Graeme Bartlett (talk) 03:48, 17 July 2018 (UTC)[reply]

I know. It's just that they are both representable by the same electronic configuration short-hand where spin is not accounted for. Plasmic Physics (talk) 06:15, 17 July 2018 (UTC)[reply]

Planting with a machine gun

I had a crazy image in mind of a Vietnam-era helicopter planting crops by machine gun and, to my surprise, actually found real web references: seeds in bullets wanted (from the final halcyon days of Obama), for home defense or something (with a YouTube video that, like every video worth watching that used to be on YouTube, has been censored) even tree planting (though not actually fired at range. But all these are written as if they're the only ones who ever thought of it - I don't know any general terms to use, or principles that apply. I would suspect, for example, that plowing may be hard to do without, and seeds planted this way might never compete for enough nutrients to be agriculturally relevant; yet I've read at times claims that plowing is actually avoidable - I'm no farmer to know. Is it possible to embed seeds in biodegradable bullets and plant a reasonably successful crop from the air? Wnt (talk) 17:46, 16 July 2018 (UTC)[reply]

...perhaps your subconscious mind conjured this misinterpreted imagery after you heard an agronomist discussing ballistic dispersal? Nimur (talk) 18:00, 16 July 2018 (UTC)[reply]

It's more likely I once glanced at the Obama-era headline; ballistic dispersal is about making seeds fly, not embedding them in the ground when they land. (That I know of ... there's probably some crazy species out there I don't know about that leaves a vine growing out the body of some wretched herbivore... yummm, Shawn Ashmore...) Wnt (talk) 18:17, 16 July 2018 (UTC)[reply]

Guerrilla gardening has popularised the term seed bomb. See DIY: Make Your Own Wildflower Seed Bombs: "The instructions are simple enough, a bit like making chocolate truffles. Takes 30 minutes." Carbon Caryatid (talk) 20:36, 16 July 2018 (UTC)[reply]

https://www.sbir.gov/sbirsearch/detail/1207769 --Guy Macon (talk) 04:12, 17 July 2018 (UTC)[reply]

I'm surprised the seeds would survive the shock from explosions. I'd have thought it would cook the seeds.. Dmcq (talk) 08:21, 17 July 2018 (UTC)[reply]

A rail gun would avoid the explosion and greatly reduce the heat. It would, obviously, induce a heavy ionized field which may or may not affect the seeds. However, I've never seen any design at all for a rail "machine" gun. All functioning models I've seen are one-shot deals with a lot of setup between shots. 209.149.113.5 (talk) 17:09, 17 July 2018 (UTC)[reply]

When Trans woman get breasts from hormones or surgery, can they feed babies breast milk?

What is best scientific answer to this question? Sphinxmystery (talk) —Preceding undated comment added 18:30, 16 July 2018 (UTC)[reply]

They can only do that after babby is formed. 173.228.123.166 (talk) 20:17, 16 July 2018 (UTC)[reply]

According to Male lactation, even some men can breastfeed. According to Witch's milk, even some babies produce this nutritious life-fluid. Carbon Caryatid (talk) 20:40, 16 July 2018 (UTC)[reply]

Implants would be of no use, and can even be problematic. Hormonal treatments would be necessary to induce lactation, just as Caryatid mentioned.--Khajidha (talk) 12:32, 17 July 2018 (UTC)[reply]

Horse chestnut sap causing blue colour

Following a recent discussion I have been trying to find information about the chemical reaction that is happening when young horse chestnut twigs are put into water and the sap causes a distinct bluish colour in the water. I have witnessed this effect on many occasions but the effect and its cause seems curiously absent from the web. Or perhaps I am inept. I wonder if there are any chemicobotanists or anybody in the house that might give me some direction or indication of the cause of the phenomenon. Richard Avery (talk) 22:45, 16 July 2018 (UTC)[reply]

This article about a closely-related species, Aesculus indica states that aesculin is the source of the blue color, which turns from clear to blue at the correct pH, see here. --Jayron 32 02:51, 17 July 2018 (UTC)[reply]

Thanks Jayron, that adds to the meagre info I have. Richard Avery (talk) 18:44, 17 July 2018 (UTC)[reply]

July 17

Impairment of dolphin function during sleep

I've heard that dolphins sleep one hemisphere of their brain at a time. Since the hemispheres of the human brain perform different complementary tasks (like, I think, the left side senses or controls the right side of the body/eye while the right side senses or controls for the other side); does that mean that one side of a dolphin's body is impaired during sleep? --129.215.47.59 (talk) 10:43, 17 July 2018 (UTC)[reply]

Your assumption that "the left side senses or controls the right side of the body/eye while the right side senses or controls for the other side" is incorrect. See Hemispherectomy and Ahad Israfil. Also see [25]. "The important functions our brain carries out are not farmed out to single distinct brain regions, but instead supported by multiple regions, often in similar but slightly different ways. If one structure breaks down, the others can pick up the slack."[26]

As for dolphins, see Dolphin#Sleeping. Also see [27][28][29] BTW, we (sort of) do it too.[30] --Guy Macon (talk) 16:03, 17 July 2018 (UTC)[reply]

While humans and other animals are forced periodically to stop all activity and sleep, dolphins have evolved alternate half-brain sleep as a means of keeping alert against predators (sharks) for more than two weeks. An experiment found that dolphins' echolocation sense was undiminished. In the future a dolphin may be fitted with a portable EEG backpack to learn more about its handling of complex tasks during the half-sleep state. Another experiment found that acquired information is transferred between the two hemispheres of the their brain. DroneB (talk) —Preceding undated comment added 16:17, 17 July 2018 (UTC)[reply]

Nutrition: How long does it take to add 10 kg (22 lb) to one's weight, while consuming 5000 kcal per day (by eating cakes)?

Current weight: 50 kg (110 lb).

Current height: 170 cm (5ft7in).

Health: good.

Sports: no. HOTmag (talk) 14:06, 17 July 2018 (UTC)[reply]

[31]. --Jayron 32 15:06, 17 July 2018 (UTC)[reply]

Thnx.

Resolved

HOTmag (talk) 18:26, 17 July 2018 (UTC)[reply]

Drowning spiders

Do spiders have any in-built resistance to water? How long does a spider take to drown? I mean ordinary small household ones, not huge furry ones like a tarantula. Thanks. 86.190.109.151 (talk) 18:20, 17 July 2018 (UTC)[reply]

Not by any means a full answer to the question, but see diving bell spider. Looie496 (talk) 18:59, 17 July 2018 (UTC)[reply]