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April 14

Moon's moons?

Are there any moons that have "moons" of their own? -- If not, why not? It seems that given enough time, there would be bits of debris with just the right trajectory to enter into orbit around a moon. —2606:A000:4C0C:E200:0:0:0:3 (talk) 05:29, 14 April 2018 (UTC)[reply]

None are known, and they would likely be unstable. See subsatellite. However, there are moons that do not orbit each other, but which make repeated close approaches to each other. See co-orbital configuration. --69.159.62.113 (talk) 06:00, 14 April 2018 (UTC)[reply]

Thanks for the links. ~~Similarly, are there any other natural satellites orbiting Earth (e.g. a meteor or cometary debris)? Again, it seems there should be.~~ —2606:A000:4C0C:E200:0:0:0:3 (talk) 06:57, 14 April 2018 (UTC) ... I found Claimed moons of Earth which sort-of answers this.[reply]

According to this answer, from the University of Cornell's Astronomy department, to a similar question, a moon of a moon is theoretically possible. As, you'll have gathered, though, we haven't actually found one yet. {the poster formerly known as 87.81.230.195} 2.218.14.51 (talk) 11:54, 14 April 2018 (UTC)[reply]

But as it notes, their orbits are generally not stable over long periods, which is why they're rare. The primary yanks on it and gradually perturbs its orbit, eventually either capturing it itself, colliding with it, or ejecting it from the system. All the stable many-body planetary systems we see are large planets with small moons relative to the primary, as with Jupiter and Saturn. The moons formed around the same time as the planet, and fell into resonances with each other, which is what keeps them stable. Everything else in the proto-system either got swept up by the proto-moons or proto-planet, herded into the rings, or ejected. Jupiter's and Saturn's rings are also in stable resonances with the primary and its moons, and in fact at least part of Saturn's rings may be a moon that got destabilized and ripped apart.

The same processes are why Earth doesn't have any other satellites. The moons usually need to form with the planet, so they can stabilize each other. None of the terrestrial planets, it looks like, even formed moons, because they aren't massive enough. Earth's moon came from a collision with another protoplanet. Some of the ejecta got blasted into orbit around Earth, and then all got swept up into the Moon. The same may have happened to Venus, but it later lost its moon. Mars's moons are captured asteroids which are unstable; Phobos will eventually crash into Mars, while Deimos will escape. The dwarf planet systems look to all be the result of cosmic bumper cars, which, along with the low mass, explains the large number of bodies. --47.146.63.87 (talk) 01:54, 15 April 2018 (UTC)[reply]

The closest detected so far are the rings of Rhea. If they exist, it would be largish particles orbiting a moon. It is a temporary orbit as they are eventually pulled into orbit around Saturn. But, theoretically, a largish rock could maintain an orbit around Rhea for a very long time. 209.149.113.5 (talk) 11:35, 17 April 2018 (UTC)[reply]

Sorry, I forgot to thank y'all for your replies. Interesting! —Same OP, new IP=2606:A000:1126:4CA:0:98F2:CFF6:1782 (talk) 01:40, 21 April 2018 (UTC)[reply]

April 15

Concrete

What is the precise mechanism for the setting of concrete? Do(es) the primary reaction(s) take place in the solid phase, the aqueous phase, or both? 2601:646:8E01:7E0B:0:0:0:9A39 (talk) 01:21, 15 April 2018 (UTC)[reply]

"Precise" is hard, as this varies according to composition and conditions. See Concrete#Curing. There are two processes though: the first one (usually a few days) is hydration, then a long term process of carbonation. The hydration is aqueous, the carbonation relies on a gas diffusing through a solid (one reason why it takes decades for thick concrete).

Much of the strength is about the duration of the hydration phase, thus the amount of hydration (and thus the strength increase) which takes place whilst the concrete is still wet enough to permit it. An over-dry mix, a wet mix placed against a dry substrate (which sucks the moisture from it), or air drying the surface are some of the factors which reduce this, thus reduce the concrete strength.

It's a big topic though, and more detail is going to need textbooks, not a simple encyclopedia entry. Look at the effects of pozzolans too, and how different ones make stronger or weaker mixes. Andy Dingley (talk) 12:25, 15 April 2018 (UTC)[reply]

It is a big story, I'm afraid you need to be like Daddy pig telling a concrete story to Peppa and George and read up on it to really get into it properly ;-) The article on concrete mentioned above is good though. Dmcq (talk) 17:05, 15 April 2018 (UTC)[reply]

So, by what mechanism does hydration proceed? 2601:646:8E01:7E0B:792F:2CDD:A29B:FC67 (talk) 07:32, 16 April 2018 (UTC)[reply]

If you really care, then get hold of a copy of Taylor, Peter C. (2013). Curing Concrete. CRC Press. ISBN 0415779529. This is expensive (>£100 locally) but seems to be the only modern, in-depth treatment of the subject. It should be in most college libraries, if they're teaching any sort of architecture, civil engineering or building course.

The problem is that this is a complex topic and it wasn't understood until the '70s (after the 1960s concrete building boom!), partly as a result of lessons learned from serious failures in materials like high alumina cement. As noted, pozzolans are important, and they just weren't properly understood for a very long time - the Romans knew of them two thousand years ago, some textbooks still mis-describe them.

Concrete mixes are well known for using either non-hydraulic or hydraulic cement. Yet some sources (and I don't see Wikipedia wording this terribly clearly) either mis-describe these, or at least are written to be very confusing. It's well known that hydraulic cements (and concretes using them) will cure underwater. Yet what is the curing mechanism? The non-hydraulic cement that does have a different curing mechanism is a lime mortar.

Lime mortars are hydrated (or 'slaked') long before use, to turn quicklime into lime putty. Lime putty is often stored for months to 'mature' it. This putty is then mixed (usually not long before use) with fines (sand) to make a lime mortar. There is endless debate as to how long either the putty or the mortar should be stored before use, and whether putty should be wet or made with only just enough water to hydrate it, so that it's a dry powder instead (this hydrated lime powder is often the form it's sold in). The curing mechanism is then carbonation by carbon dioxide from the air - hydration doesn't cure lime, that was already done when it was slaked. Note that cured lime mortars are much more permeable than cement mortars, so they're breathing more carbon dioxide, more quickly. Curing begins as soon as the hydrated lime is exposed to the air - either applied as mortar, or just stored as wet maturing putty. Maturing it, maybe for months, gives a slightly pre-carbonated and cured mortar which will be harder, stronger and more difficult to work. As the benefit of lime mortar is often that it's less strong than a cement mortar, but may be more workable to allow for artistic effects, then this can either be a good or bad thing.

If lime is mixed with a pozzolan, then you get a cement instead (this is a massive simplification). There are many types, some expensive, some cheap. Some sources will argue as to what a pozzolan is, and whether Portland cement (which uses cheap ground clinker and gypsum) has one at all - I take the modern view, that all such materials are pozzolans (or at least act as one), and it's this which changes lime mortars to hydraulic cements. Hydraulic cement needs to be stored dry (unlike lime putty) and although it can be stored for long periods, it's not improved by this (unlike lime), and so is best used rapidly. Once any water is added, a hydration reaction begins and this is the start of curing. It must be kept moist during curing and the other aspect of a hydraulic cement is that it can even be submerged during curing. Now we're back to my original post - hydration (wet) takes a few days, and then carbonation (probably dry) takes years.

It's not a simple split between lime mortar and hydraulic cement either. There are many inbetween, either hydraulic lime mortars (which cure by hydration, can't be stored wet once mixed, and may be used so wet as to be under water) or non-hydraulic cements, which also cure by hydration but can't be submerged during curing. This is complicated, there are many variants, there are still old books and old views around which argue the definitions. If you want more, read Taylor's book, or something like it, as you're probably beyond what generalists can tell you here. Andy Dingley (talk) 10:30, 16 April 2018 (UTC)[reply]

April 16

Amine and Nitramin

I don't understand why there is written R+ or R- sometimes, otherwise there is written R1 and R2. What does the R stand for? --Saegen zeugen des sofas jehovas (talk) 00:35, 16 April 2018 (UTC)[reply]

The R refers to a side chain, basically a part of the molecule that is there but whose chemistry is not being considered at the moment for some reason. Usually the R-group is assumed to be a hydrocarbon. When multiple side chains are attached to the same molecule being considered, they are given distinct names (such as R1 and R2) so that the reader knows they are different, or at least could be. Sometimes the R group is used because what is being discussed is true for very many side chains. For instance, all molecules R'OOR" where R' and R" represent hydrocarbons have certain chemical properties in common no matter what particular hydrocarbons the R's represent. Someguy1221 (talk) 00:46, 16 April 2018 (UTC)[reply]

sounds interesting, thank you :) --Saegen zeugen des sofas jehovas (talk) 01:10, 16 April 2018 (UTC)[reply]

E Ink

Some E Ink device manuals caution against exposure to long-duration direct sunlight: "Avoid exposing your Cybook Odyssey to direct sunlight or strong ultraviolet light for extended periods of time."[1]

I trying to figure out which of the following is the real reason here:

1. Direct sunlight, more specifically the UV rays in sunlight, permanently damages E Ink displays.

2. Direct sunlight causes temporary performance issues in E Ink displays, but returns to normal after removal from sunlight. This thread[2] seems to support this theory.

3. There is no problem and this is just the standard "cover your ass" disclaimer from manufactures. The E Ink article says: "Advantages of E Ink include low power usage, flexibility, durability and ruggedness and better readability under direct sunlight." Without noting any particular problems associated with E Ink displays under direct sunlight. Mũeller (talk) 02:48, 16 April 2018 (UTC)[reply]

FWIW, if you leave an LCD display, such as found on a DVM, in the Australian sun it goes black. Flip it over and it reverts to normal, eventually. Greglocock (talk) 03:46, 16 April 2018 (UTC)[reply]

Thank you for the input. Mũeller (talk) 04:35, 16 April 2018 (UTC)[reply]

There are various reports of problems with e-ink screens left in the sun here [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]. Those are all old, and you'd note inconsistent reports even within the same model, with some suggesting a few devices are particularly affected even in a very short time and you may be able to get a warranty replacement if you device is that bad.

It sounds like some the problem is a lot less with newer devices than it was before per these more recent sources [14] [15] [16]. I'd note some people suggest no problems, but others suggest there may still be problems long term. Considering the vast differences in what being in the sun can mean between users and countries, and that most people are just reporting problems they've had after a fair while with a unknown cause (i.e. it's not like they've had a random sampling of devices some of which have been left in the sun and some haven't at random and they've then compared the devices) it's difficult to really know whether any of these more recent reports of problems are due to the sun or due to something else, and if the sun can cause problems what level is required. I'd also note that most of these are simply referring to normal use in the sun, rather than just leaving a device in the sun.

In any case I wouldn't assume leaving the device in the sun has no effect since both the heat an UV are something which can have consequences, whether or not it's significant enough to be noticed in ordinary use. (I think many people who hang up their washing outdoors will now that even UV stabilised pegs last a lot shorter when left in the sun all the time even in cloudy temperate countries.) The UV can be blocked to some extent (one of the recent sources suggest one reason why some earlier devices were so affected was because production or design flaw leaving out a UV blocking filter), still there are always going to be limits considering cost, size and weight, utility and production requirements. (Also you shouldn't assume this problem is only because of the eink screen, it may be the typical use profile of a tablet, phone or laptop are such that although leaving it in the sun may cause problems, it's simply not worth warning people in such a direct way.)

Nil Einne (talk) 11:41, 16 April 2018 (UTC)[reply]

To whom mostly children similar or look like?

If I would like to know statistically to whom, in the most of the times, the children resemble genotypically and phenotypically? Do children normally more resemble to their mom or their father or their mother? (I know that it depends on genetics but I'm asking generally speaking rather than about specific cases)93.126.116.89 (talk) 04:03, 16 April 2018 (UTC)[reply]

Strictly WP:OR, but "generally speaking", babies resemble Winston Churchill and/or Alfred Hitchcock. 2606:A000:4C0C:E200:0:0:0:3 (talk) 07:19, 16 April 2018 (UTC)[reply]

Indeed. Some years ago, was reading an autobiography of a real-life Emma Peel secret agent during WWII, can't recall her name, where she remembered meeting Churchill at odd hours of the night, where his dress and appearance made him seem identical to a giant baby.John Z (talk) 20:08, 16 April 2018 (UTC)[reply]

Scientific American reported in 2011 that "Recent studies do not support the claim of an enhanced resemblance between fathers and their young offspring". Fact or Fiction: Do Babies Resemble Their Fathers More Than Their Mothers? It refers to previous studies claiming benefits to paternal resemblance. Carbon Caryatid (talk) 15:32, 16 April 2018 (UTC)[reply]

There have been more studies since then. Speciate (talk) 18:00, 16 April 2018 (UTC)[reply]

One of the things that makes these sorts of things hard to study is the lack of a reliable way of quantifying "physical resemblence". On the one hand, Biometrics can be used to assess some arbitrary degree of relatedness between two faces, on the other hand Face perception in Humans is a complex process that does not at all work like automated systems used for Biometric identification (i.e. Out-group homogeneity, etc.) --Jayron 32 16:46, 16 April 2018 (UTC)[reply]

Double-blind studies show that babies resemble their fathers much more than their mothers at birth, but the effect has faded at 6 months. This has to do with preventing infanticide and uses gene silencing. Speciate (talk) 17:56, 16 April 2018 (UTC)[reply]

Do you have those studies? It would really add to the discussion to be able to read them. --Jayron 32 18:13, 16 April 2018 (UTC)[reply]

Research into infanticide in animals is in part motivated by the desire to understand human behaviors, such as child abuse. ^[1] DroneB (talk) 18:46, 16 April 2018 (UTC)[reply]

Sounds very unlikely to me, I bet some other paper proves it wrong. One only has to consider how many children are born from extramarital affairs and the low number of infanticides to see it would pay to make identification in the first few weeks more difficult rather than easier. Dmcq (talk) 22:39, 16 April 2018 (UTC)[reply]

Also in a study of similarity I think they really should have men compare the baby to the father and other men known by the mother. :) Dmcq (talk) 22:43, 16 April 2018 (UTC)[reply]

Like the antique joke about a child looking like the milkman. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:16, 17 April 2018 (UTC)[reply]

References

^ Bayard Webster (1982-08-17). "Infanticide: Animal behavior scrutinized for clues to humans". The New York Times. Retrieved 2008-01-18. {{cite news}}: Italic or bold markup not allowed in: |publisher= (help)

April 17

Crowley's ridge loess

How deep is the loess on Crowley's ridge and what kind of rock is under the loess?Hoover12345! (talk) 00:32, 17 April 2018 (UTC)[reply]

Our article (Crowley's Ridge) does not say, and the only ref that looks promising has a malformed URL. The authors fo that paper are Google Muhs and Bettis. a google on these names show them to be USGS scientists that have published extensively about last-glacial loess formations. -Arch dude (talk) 00:52, 17 April 2018 (UTC)[reply]

I have updated two refs in our article to have working open access URLs for the content. One is an archive, the other is at a different location. Although I didn't check the URL for which I found a new location for the content which is not behind a paywall, I strongly suspect it too was not malformed simply a dead but correctly formatted URL for its time, especially since it is a very similar USGS URL. (I have also added DOIs so the content can hopefully be more easily found, at least behind a paywall, should either URL stop working again.) Nil Einne (talk) 12:49, 17 April 2018 (UTC)[reply]

The map on page 26 of [17] shows a thickness of 5-10 meters. -Arch dude (talk) 00:59, 17 April 2018 (UTC)[reply]
It is underlain by the Lafayette gravel. See [18]. Found by googling for <geology of crowley's ridge>. If you can understand this stuff, please expand our article. -Arch dude (talk) 01:10, 17 April 2018 (UTC)[reply]

How much surface can you plate with one gram of gold

Using modern gold plating, how much surface (of glass or jewels) can you cover per gram of gold? I understand that gold can be spread over a really large surface. I just don't know how large it is. --Doroletho (talk) 13:21, 17 April 2018 (UTC)[reply]

According to this, gold leaf can be as thin as about 0.1 microns. Gold has a density of 19.33 g/cm³. That means that 1 gram of gold has a volume of 1/19.33 = 0.05173 cm³ since 0.1 microns = 1 x 10^-7 meters, that's 1 x 10^-5 cm, so 0.05173/10^-5 = 5173 cm² for the area covered by that leaf. --Jayron 32 13:42, 17 April 2018 (UTC)[reply]

For people as dumb as me: the comma in "5,173cm2" above is a thousands separators, not a decimal point. So that is roughly half a square meter. Tigraan^{Click here to contact me} 13:55, 17 April 2018 (UTC)[reply]

This site says that 1000 leaves of gold leaf will cover 79 square feet and has a mass of 18 to 23 grams. 79 square feet is about 7.3 square meters, so 18 grams per 1000 leaves gives a coverage of 0.4 square meters per gram - very close to User:Jayron32's estimate. Gandalf61 (talk) 15:57, 17 April 2018 (UTC)[reply]

However, when electroplating, much thinner coatings are possible. This site [19] sells microscope slides with 100 Å (i.e., 10 nm or 0.01 micron) coatings, so that would cover ten times the area computed above. Sufficiently thin gold coatings are transparent,. -Arch dude (talk) 16:11, 17 April 2018 (UTC)[reply]

Slightly thicker coatings are transparent red. LongHairedFop (talk) 18:03, 17 April 2018 (UTC)[reply]

I think we ought to distinguish an important practical detail:

The total amount of surface-area covered by one gram of gold is not identical to the surface area you would cover if you added one gram of gold to a real process or machine. There are inefficiencies and losses to consider. Not all the gold ends up where you want it to go!

For every gram of gold input to an electroplating process machine, or to a gold sputtering machine, only a fraction of that gold ends up on the final product. In the case of a sputtering machine, a very huge percentage of the gold ends up as waste-product.

Here's a commonly-cited paper, from the Journal of Vacuum Science and Technology: Ion Sputtering Yield Measurements for Submicrometer Thin Films (1988), which you'll surely find in the archives of any great physical sciences research library.

I'm not very familiar with electroplating - maybe you can get some answers from our regular contributors who are chemists - but I bet electroplating makes more efficient use of the input material than vacuum sputtering! Even still, there are some cases where sputtering is the best and only option - for example, if you want to shoot an scanning electron microscope at a gummy bear, you've got to sputter! The unique preparation of the gold-plated gummy-bear to make it suitable for the SEM is a true art form, a sort of rite-of-passage in the vacuum chamber that one must learn if one wishes to truly master the microscope.

Nimur (talk) 18:26, 17 April 2018 (UTC)[reply]

I know nothing about gold sputtering for electron microscopy, but in other processes using gold, the wast stream is reproicessed to recover the gold. Thus,at the system level, (almost) all of the gold is eventually used. Surely you guys don't jut flush this down the drain? -Arch dude (talk) 22:24, 17 April 2018 (UTC)[reply]

Using the density of 19.3 g/cm^3 and the atomic weight of 197 u, it follows that the surface density of gold is 4.96*10^(-7) g/cm^2, therefore the maximum possible area a gram of gold can cover is about 202 squared meters. Count Iblis (talk) 00:34, 18 April 2018 (UTC)[reply]

Drinking water and hormones

When a human drinks water, does the body release a hormone with diuretic effect? Does it store less water? I imagined that it could exist a similar mechanism to the mechanism of eating/secreting insulin, but related to hydration. Smelling food stimulates release of insulin (which stimulates glucose uptake), since the body anticipates more of it is on its way. --Hofhof (talk) 19:48, 17 April 2018 (UTC)[reply]

You may find some information at one of the items in Water retention. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:03, 17 April 2018 (UTC)[reply]

When humans drink, and that water is absorbed, we produce less of an anti-diuretic hormone called, unsurprisingly, antidiuretic hormone (ADH) and otherwise known as vasopressin. That does imply that under normal conditions we have a constant low rate of release of this hormone which is switched off, or decreased, after drinking. Klbrain (talk) 23:33, 19 April 2018 (UTC)[reply]

Crowley's ridge

I think my real question is how does something made out of loess and gravel not get eroded away by the Mississippi River over all its meanderings?Hoover12345! (talk) 21:18, 17 April 2018 (UTC)[reply]

How do you know it hasn't already been eroded some? ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:36, 17 April 2018 (UTC)[reply]

Because in that part of the river, deposition rather than erosion is the predominant process. 2601:646:8E01:7E0B:792F:2CDD:A29B:FC67 (talk) 03:08, 18 April 2018 (UTC)[reply]

Looking at meander maps going back eons, the Mississippi has been on both sides of the ridge and Crowley's ridge is never under water. — Preceding unsigned comment added by Hoover12345! (talk • contribs) 14:35, 18 April 2018 (UTC)[reply]

April 18

domestic or wild

Are humans considered domestic or wild animals? — Preceding unsigned comment added by 188.159.34.230 (talk) 08:25, 18 April 2018 (UTC)[reply]

Domestic, definitely. We live in homes. Or, maybe not, because no one has breed us selectively (consciously or not) for a specific purpose.

On the other hand, I wonder whether the question makes sense. We define domestic/wild in relationship to humans.--Doroletho (talk) 09:01, 18 April 2018 (UTC)[reply]

Humans possess a number of genetic markers of domestication. Abductive (reasoning) 09:18, 18 April 2018 (UTC)[reply]

Sure, humans undergo neoteny too. --Doroletho (talk) 10:54, 18 April 2018 (UTC)[reply]

This is the "is water wet?" type of question. It's ultimatly an arbitrary semantic distinction that depends on how precisely, and with what definition, you define your terms to start with. The best answer is probably Doroletho's first answer, which is " wonder whether the question makes sense. We define domestic/wild in relationship to humans?" Any attempt to generate a more rigorous answer is likely to generate lots of pointless all-caps writing between two camps who insist they are each right. --Jayron 32 12:48, 18 April 2018 (UTC)[reply]

See feral child. 92.19.169.232 (talk) 15:43, 18 April 2018 (UTC)[reply]

And maybe ponder homeless people. InedibleHulk (talk) 23:57, April 18, 2018 (UTC)

Poul Anderson was very clear on the question, or at least one of his protagonists was. I'm not sure if it was Dominic Flandry or Nicholas van Rijn. Probably Flandry because I don't remember the speech being in broken English. But in any case the answer was "wild", and moreover that that was what they ought to be. --Trovatore (talk) 00:23, 19 April 2018 (UTC)[reply]

Agree that this is a mostly nonsensical distinction for humans, but modern people do meet most of the considerations laid out here. Matt Deres (talk) 14:20, 19 April 2018 (UTC)[reply]

FYI, in addition to this being an obvious invitation to debate, the OP is now blocked. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:48, 19 April 2018 (UTC)[reply]

To clarify, this is no reflection on the OP. The IP has been automatically blocked as a proxy, but then many of the IPs in public libraries are proxies. 92.19.169.232 (talk) 18:03, 19 April 2018 (UTC)[reply]

Sure. A public library in Teheran. ←Baseball Bugs ^{What's up, Doc?} carrots→ 18:29, 19 April 2018 (UTC)[reply]

See self-domestication. 169.228.147.129 (talk) 03:07, 20 April 2018 (UTC)[reply]

How to dissuade conspiracy theorists?

Is there a way to dissuade conspiracy theorists from their conspiracy theories? I've debated conspiracy and fringe theorists before - everything from 9/11 truthers, to anti-vaxxers to climate change deniers. I've been able to occasionally dissuade someone on a particular subpoint, but not the overall theory. Have any psychologists studied this and come up with any effective techniques? Or conspiracy theorists a lost cause? A Quest For Knowledge (talk) 14:12, 18 April 2018 (UTC)[reply]

Reasoning will never make a man correct an ill opinion, which by reasoning he never acquired... Jonathan Swift, 1720. If a person has an unreasonable opinion, by definition, that person does not use facts, reason, and logic to arrive at their own opinions. They will be impervious to any attempt to use facts, logic, and reason to get them to change their opinion. It's a lost cause; our role in society should be to marginalize and minimize the effect of such people on the minds of those who may be influenced by them. If they cared about using reason and facts to arrive at their opinions, they already would have done so. --Jayron 32 14:24, 18 April 2018 (UTC)[reply]

The tendency to search for, interpret, favor, and recall information in a way that confirms preexisting beliefs is called confirmation bias or belief perseverance. It is present to some extent in everyone's thinking. It is probably an adaptive behavior, as taking time to think through every new piece of information from scratch would be dangerous ("What is that stripy thing ? Could it be a tiger ? It certainly looks like a tiger. But maybe it is an illusion. Or maybe I am dreaming ..."). Our article on confirmation bias is very informative. Gandalf61 (talk) 14:31, 18 April 2018 (UTC)[reply]

Not an answer but an observation: despite the fact that, as the previous two editors have righly stated, and is in fact widely known, people do not buy into conspiracy theories based on reasoning (how exactly people "fall into" those beliefs has probably been the object of numerous books, dissertations and articles, maybe it resembles the way people join cults and religions, and maybe even some forms of mental disease) nevertheless it is remarkable that conspiracy theories masquerade as logical constructs, pretend to be rational theories (in constrast to cults and religions). I find this remarkable in view of the fact we know that the primary motivation is not rational. I have my own conjecture as to why this is so, but that would be simply stating an opinion which we're not supposed to do here. Basemetal 16:14, 18 April 2018 (UTC)[reply]

The issue is that conspiracy theories use acceptable logic protocols (like the scientific method or formal logic or other valid decision making protocols) and flip them on their head. These logical constructs are unidirectional. The start with the null hypothesis (tabula rasa, blank slate, etc.) and then use evidence to provide conclusions regarding truth. That is, you start with a question "Does X happen" and then you gather all available evidence without prejudice, assess the evidence using neutral methods of assessments for reliability, and draw conclusions regarding your initial hypothesis. Conspiracy theorists do this BACKWARDS. They start with the conclusion "What I believe is true", THEN they assess evidence based on whether or not it supports the conclusion THEN they develop questions that lead inexoribly only to their conclusions. That's not reason, that's cherry picking and exactly wrong. The thing about conspiracy theories is they all fail the basic test of falsifiability; in the sense that they have assumed that their conclusion could never be proven wrong because it has already been accepted as right, and then they work backwards to gather "proof". Valid reason works the other way, it starts with a proposition which could actually be wrong as much as it could be right, and then willingly accepts that if it is proven wrong, it is wrong. --Jayron 32 16:35, 18 April 2018 (UTC)[reply]

Yes Jayron, everything you say is true, except... you misunderstood my point. Note I said those "theories" masquerade as rational theories. That masquerade is precisely what you so well characterized in your reply. However my question was different, namely, why the need to masquerade? What role does that masquerade play in the process of acquiring believers, since we know those believers do not come to that belief based on rational arguments? Are you saying that those people come to those beliefs because they are deluded by the pretense of rationality of those theories and do not notice their logical flaws? I doubt it. I believe they want to be deluded and choose to ignore those flaws when they are pointed out to them. But then why go to all that trouble. Again, what role does that masquerade play? Two of Karl Popper's favorite examples of non-falsifiable pseudo-scientific theories were Psychoanalysis and Marxism, two theories that insist loudly on how scientific they are. I don't think you can call Marxism or Psychoanalysis conspiracy theories. Here I think we know how people come to buy into them. Those people are in general rational, intelligent, honest people that can be genuinely misled by the pretense of rationality and do not see the logical flaws that you mention until after it's too late. Does that work the same in genuine conspiracy theories such as 9/11, Holocaust as a hoax, flat earth, hollow earth, reptilian space invaders or what have you? My question was simply what role does that rational masquerade play in attracting believers, since we know it is not strictly the logic, flawed or not, that brings them there. I guess every conspiracy theory is different and every conspiracy theorist has their own motivation but it'd be interesting to understand the process, conspiracy theory by conspiracy theory. Basemetal 19:43, 18 April 2018 (UTC)[reply]

I was expanding on your point, not refuting it. I'm sorry that wasn't clear; I thought that by agreeing with you that would have helped make it obvious. Sorry about that. --Jayron 32 23:55, 18 April 2018 (UTC)[reply]

No, I didn't suggest you were refuting what I had said, as you in fact analyzed the pseudo-logical structure of those theories extremely well, just that you left one point out, which is of particular interest to me, namely the question why are they structured that way? how does it help them gain adherents? when we know reasoning and argumentation has nothing to do with it. Of course no one is under any obligation to answer all the questions everbody asks, but I was hoping to hear something about that. Ok, so I'll state my conjecture, which is strictly OR. I'm hoping to hear some sourced data in response if anybody has any: my guess is that their pseudo-logical structure is a kind of weaponization. They are structured like this not so much to convince their adherents, as to give their adherents arguments to answer those who debate them. It doesn't matter that those arguments are flawed, it still gives them something to say in a debate. It may have to do with the fact that we live in a world where the rational, scientific paradigm has gain such preeminence that even they are forced to acknowledge it and disguise their theories as logical constructs (of course we know, as you characterized them, very flawed ones). This is how creationism, that meant simple blind adherence to the words of the Bible, became "intelligent design", supposedly an alternative scientific theory. I assume a conspiracy theory in the 17th century did not need to do that. In fact we would not even call it a conspiracy theory. But in the 20th century they have willy nilly to conform to the main paradigm (even though they in some sense deny it). Anyway, that is strictly OR as I said, I'm hoping to hear some real data from you or anyone who's run into reliable rigorously researched stuff on this question. Basemetal 00:49, 19 April 2018 (UTC)[reply]

We scientists categorically suffer a deficency in formal study of rhetoric; we presume - with neither evidence nor proof! - that the best method of persuasion is a method that relies on correctness. Our equally-intelligent peers who spend just as many years specializing in the social sciences and liberal arts will often trump our case by relying on the defeasible argument - things that we would like to debase as "logical fallacies" or "invalid arguments". Viz., contrast two cases for and against a simple fact: "the earth is ROUND and we have collected of a plethora of observational evidence," opposed against the perhaps more convincing counter-argument, "the earth is flat and I will punch you." The latter argument does not depend on being correct, or reasonable; you cannot win that argument by disagreeing and proving; you cannot win that argument even by accepting the opposing case; as a rhetorical method, it depends on no assumptions; as a means of persuasion, it is faster, more efficient, and more robust than almost any other reasonable method. If we apply academic deconstruction to the argument's rhetorical style, or try to parse whether our opponent's use of the logical conjunction was unintentional, we are punched before we even establish the premises, and long before we follow the premises to their illogical conclusion.

The moral of this story, perhaps, is that we - as scientists - should not immediately assume we will triumph simply because we are correct. If our objective is to be correct, our scientific methodology and its logical underpinnings are our most powerful armament. If our objective is to win, we may often have no recourse except to rely on "incorrect" methods.

Nimur (talk) 16:52, 18 April 2018 (UTC)[reply]

...and when we adopt this wisdom and its methodology, we may defeat our opponent without consequence, because even though though it is incorrect to punch somebody - most places have laws against assault! - the legal system is not held to the same standards of "completeness and correctness" that we demand in, say, a proof of a theorem of abstract algebra. Nimur (talk) 17:07, 18 April 2018 (UTC)[reply]

The simple answer is NO. For example, no amount of evidence will make a flat-earther change his mind about the earth being flat. And the nature of the earth is one of the more easily demonstrable facts. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:52, 18 April 2018 (UTC)[reply]

The OP didn't ask for a method using evidence. They asked 'Is there a way to dissuade conspiracy theorists from their conspiracy theories?'. And there are ways to do that. It is very difficult though - you have to gain their trust and respect and the people they respect are people who are on the same wavelength as them. Dmcq (talk) 20:35, 18 April 2018 (UTC)[reply]

There are all kinds of cognitive biases (here is an extensive list of cognitive biases which are worth studying, avoiding and/or exploiting) and a quick google search on the term "influence" brings up psychologist's Robert Cialdini's book Influence: The Psychology of Persuasion and he also wrote Influence: Science and Practice. Just how deluded, incompetent, intelligent, informed and receptive any audience is, is going to vary a great deal. Moreover, you can't easily influence or "convince" trolls who don't care or likely know that they get it all wrong or probably wrong, because they are getting rewarded in some way (money, attention, humor, esoteric "expertise", etc) regardless of how absurd their dress-it-up make-it-up crack-pottery they espouse is. Then there are the large number of incompetents (that seem to be over-represented in most areas) that don't know or barely know any of the science. Add to that wide-spread preconceptions, misconceptions, and group think, better (saner) explanations might be perceived as flawed, therefore cranks will go to great lengths to gloss over gaping holes in order to maintain their paradigms. Obviously it can be hard to combat that if they are deluded too, but it is possible to be persuasive, and Cialdini has written several books on this topic. -Modocc (talk) 21:25, 18 April 2018 (UTC)[reply]

As fabled BS artist and sketchy limousine explosion survivor Vince McMahon once (allegedly) reasoned "I can't be on TV if I'm dead." That's not to say you should blow up their limos, only that it (in theory) would make them forget everything they think they know about everything forever. Not great for persuasional pursuits, though, which are the better ideas in the long run.

To that end, I suggest simply empowering and assuring them. Sounds like a dumb idea, but my crazy friend here says kooks like conspiracy because they have too little of one and not enough of the other. Perhaps with more confidence, they could find the strength to admit they're wrong about a less important lie they had to cling to before. Or perhaps they could turn into ultraconfident superloons with the potential to trump Trump. Latter's less likely, in my own humble opinion. InedibleHulk (talk) 23:01, April 18, 2018 (UTC)

That link squares with what I've observed over the years: Believers in these goofy theories generally feel powerless. By latching onto one or more conspiracy theories, they feel like they have some sort of "inside" knowledge that the general public is oblivious to, and hence have more power. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:22, 18 April 2018 (UTC)[reply]

Powerless and uncertain. Many powerful people believe things simply for not knowing them as well as they feel they should. But when you know the truth, you don't need to convince anyone about "the truth", especially online. InedibleHulk (talk) 23:44, April 18, 2018 (UTC)

Yes, which is why it's pointless to debate conspiracy theorists except when they try to impose their wacko theories on Wikipedia. The debate over the moon landing stuff still burns in my memory. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:48, 19 April 2018 (UTC)[reply]

Uv dat dey ain’t no doubt. InedibleHulk (talk) 01:21, April 19, 2018 (UTC)

From what I've read, counting racism as one of the most vile conspiracy theories out there, it takes a lot of patient and kind interaction with the hated ethnicity. There may be an "AHA!" moment where it finally clicks that all humanity deserves love, but it's still not an overnight thing.

There's also young earth creationists who advocate a conspiracy theory that evolution is atheist propaganda. Regular, calm, and patient interaction with co-religionists who also happen to accept evolution takes a lot of the bite out of their arguments. They might still occasionally push that we should "teach the controversy" and insist that the world is only 6000 years old, but they throw far fewer hissy-fit tantrums over evolution being the mainstream scientific consensus than YECers who are convinced that evolution is a religious doctrine.

I've also seen that a lot of conspiracy theorists are using the conspiracy theory to displace their worry. Worried about not getting a date? Imagine that some sort of feminazi conspiracy is out to emasculate alpha males, instead of considering reasons why women may not want to date you. Worried about keeping a steady job? Blame immigrants instead of automation shifting the job market from manufacturing to service to... whatever will be left once AI takes off. Helping them make themselves aware of what their real worries are, helping them make themselves aware that their understanding of the "other side" is really a rage totem constructed to enforce a group identity, and helping them learn what similarities they have with the "other side"* to see them as allies (even if they still disagree with them) are all tricky but the surest way to make them give up on these conspiracy theories in these cases. Unfortunately, it's entirely dependent on catching a Teachable moment and knowing how to phrase things so they like what they hear and interpret it as their own realization.

^*

Except Nazis, because the only thing that distinguishes Nazis from any other fascist or nationalist ideology is successful genocide.

Ridicule is a double edged sword. Someone who is open to conspiracy theories might be dissuaded from looking further into that particular conspiracy theory. Devout believers, however, will view it as persecution and triple their volume. Ian.thomson (talk) 23:27, 18 April 2018 (UTC)[reply]

Regarding your comment about the Nazis, they were hardly the only ideology to successfully commit genocide -- Islam has done the same, and so did communism, so you should apply the same yardstick to all of them and by your own standards conclude that there can therefore be no common ground with them either! 2601:646:8E01:7E0B:792F:2CDD:A29B:FC67 (talk) 01:29, 20 April 2018 (UTC)[reply]

Basemetal asks "why". Why? There are probably as many reasons at their are conspiracy theorists, but a few stick out pretty often: 1) Because they are the last believers in an ordered universe, where everything happens according to someone's plan, and since evil things happen, that someone must be evil, and the plan must be very bad; 2) Because there is a certain joy in knowing a secret that no one else does; related, 3) There is a certain joy in being special, in being smarter than all the sheep who can't see what is real; 4) Because however someone arrived at a belief, they have an absolute pathological aversion to ever admitting they might be wrong, building ever more elaborate explanations to avoid the ignominy of having to admit a mistake; and related, 5) some people legitimately suffer from persecutory delusions, in which they believe that anyone who wrongs them for any reason (including such simple things as simply pointing out a mistake they made) must be part of a grand conspiracy against them. That is why they start with the premise, "I am right", and then from there it's just motivated reasoning in an effort to convince themselves that is still the case. Someguy1221 (talk) 01:05, 19 April 2018 (UTC)[reply]

Hence the popularity of this oldie:[20] ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:14, 19 April 2018 (UTC)[reply]

LOL. (Or sigh). Thank you Someguy. I did ask "why". But not "why are there conspiracy theorists, conspiracy theories and people who believe in them?". There's no doubt these are extremely interesting questions but this was not my question. I asked why something else. I tried to be as clear as I could but apparently I failed. Basemetal 02:15, 19 April 2018 (UTC)[reply]

Oh right, well, to get to the "why" that you actually asked, it's very simple: cognitive dissonance. Or more specifically, it's a means to cope with it. Cognitive dissonance itself is merely the act of believing two contradictory things at the same time. The exciting bit is how people do this. You need a way to protect your brain from the pain of contradiction by convincing yourself that the two facts do not contradict one-another. It often surprises people to find out that a lot of conspiracy theorists are actually highly intelligent. Some are even successful businessmen, scientists or engineers. How and why would a person like this believe something so ludicrous as the Sandy Hook conspiracies, for instance? The answer, I think, starts with something from the list I gave above, and then proceeds through cognitive dissonance. Take a smart person who simultaneously believes that A) He is a smart person who makes decisions based on a rational, logical, explicable thought process; and B) alien lizard people comprise a secret jewish islamic atheist deep state that is out to destroy Donald Trump and take away mah guns so that everyone will be gay. The arguments for thought 'B' have to masquerade as scientific, or else the theorist can't believe thought 'A' in his head. He has to render the theory so intricate and convoluted that it simultaneously appears to be scientific but is actually unfalsifiable, so he can pretend it's science without ever having to face being wrong. It has to be complicated enough that he can fool himself. You know, that, or he's actually just insane. It can be hard to tell, and sometimes it seems like one can lead to the other. Someguy1221 (talk) 03:06, 19 April 2018 (UTC)[reply]

Asking detailed questions and letting the believer in the conspiracy theory do most to the talking, may work. This method can also be used more in general where someone believes in something that's inconsistent with the evidence, take e.g. a believer in homeopathy or astrology. Most people are capable of rationally analyzing a problem, they are able to apply rational reasoning to their pet theories and come to the conclusion that it's all nonsense, but for various reasons mentioned in this thread, they choose to not do that. If you then talk to such a person not by lecturing why what they believe in is wrong, but instead ask questions about issues that don't seem to add up and let them just go on explaining that in detail, they can't go on the defensive and invoke the usual conspiracies anymore. So, it's then not about what their opponents are supposedly doing, but it's purely about what they themselves believe in. Count Iblis (talk) 04:29, 19 April 2018 (UTC)[reply]

I can see that falling into accidental indoctrination, though. If you ask a hardcore believer about the things that don't add up, they'll reply that either:

the evidence is wrong or a forgery by the conspirators,
the evidence doesn't really contradict the conspiracy theory in the light of this other part of the conspiracy theory,
the mainstream "account" contains mistakes too and scientists don't know everything, so therefore it's not an issue if the conspiracy theory does not yet explain every facet of reality.

Softcore believers could very well decide "ok, this does seem ridiculous," but this could also become an opportunity for them to start studying the conspiracy theory even more.

Most conspiracy theorists (the ones who didn't need to be on serious medication) I've encountered use conspiracy theories to displace some other fear that they'd feel powerless to change (or else would have to drop some deep-seated personality trait). Without that situation changing, they're less likely to abandon that paranoid mental crutch. Ian.thomson (talk) 05:02, 19 April 2018 (UTC)[reply]

Btw, that is called the Socratic method. Someguy1221 (talk) 04:42, 19 April 2018 (UTC)[reply]

I know people talk about being in an in-group and countering fear. However I wonder if a lot of it isn't an exaggerated form of needing an explanation. One thing a lot of people do is just go for an explanation even if they don't have enough evidence of anything, they just don't seem able to say I don't know yet. Combine that with needing to defend their oown explanations and you're halfway towards a conspiracy theory. Dmcq (talk) 08:42, 19 April 2018 (UTC)[reply]

When reading this abstract one will encounter a misspelling. A missing symbol strongly associated with love and persecution complexes... it's mind-blowing, even insane, or at least entertaining, how events are movers of thought and vice versa. Like NPR's Wait Wait Don't Tell Me's entertaining Bluff the Listener. Some listeners are simply better at distinguishing what is a real scoop or not than others and karma rocks. InedibleHulk's reference states "We are constantly fabricating or “discovering” stories that seem to explain the world." So yes we are doing that, and I cringe when people are unfairly targeted and scapegoated... Damn the grocery store tabloids and the doomsday cults. Sadly.... history.. is replete.... with people that have conspired to jail and kill dissidents, plunder them, nuke, behead and otherwise destroy their enemies, assault each other, mob one another, pillage and subjugate the vanquished (take away their guns as well as enslave them), cheat the suckers, lie incessantly, corrupt the government with insane experiments and tweet propaganda about it. And the gerrymandering and racketeering and the bloody operations and conspiracies, or the mundane comedians are not even wacky stories... sniff. <sigh> The 1977 study with the misspelling I linked to asserts that any truth that involves correlations and/or contingencies can be difficult to process thus our minds take short-cuts, but can get them wrong. Moreover, I very recently read a study that showed that intuitive people are better on average at discovering patterns in images. That's useful if people can filter those patterns appropriately and are thus able to better explore, discover and learn... or become paranoid theorists in their old age if they have impaired executive functions. --Modocc (talk) 14:37, 19 April 2018 (UTC)[reply]

I can't help but notice you mispelled three ellipses in two entirely distinct ways there. Was that some sort of political statement? Or is it a code? InedibleHulk (talk) 22:36, April 19, 2018 (UTC)

In my mind's eye it represents placing and removing the football. So the answer to both your questions is yes. Modocc (talk) 03:25, 20 April 2018 (UTC)[reply]

I think it is a lost cause. In my opinion, a "conspiracy theory" is what we used to call a "paranoid delusion". Bubba73 ^{You talkin' to me?} 17:21, 19 April 2018 (UTC)[reply]

I google imaged the old joke "Just because you're paranoid doesn't mean they're not out to get you." Hundreds of variations of it exist, as prints, T-shirts, whatever. That's the philosophy of the typical conspiracy theorist. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:46, 19 April 2018 (UTC)[reply]

People are still free to have paranoid delusions without any semblance of conspiracy. Monsters at the foot of the bed, for instance, are usually lone wolves. Figuratively, of course. They're literally more closely related to bats. The point is, they're terrifying for their own sakes and their perceivers', nobody else's business. Same with the idea that these beasts are born when a tree falls in the forest and nobody's around to disprove it; they don't kill your dogs and enter your shack late at night for any convoluted reason that could gain traction online, they're just scared, too. Boring and true, I tell ya! InedibleHulk (talk) 22:51, April 19, 2018 (UTC)

My feeling is that there "conspiracy theories" and disinformation are intimately related. If a lot of people are saying something crazy, there's a fair chance there's a conspiracy behind that. For example, the whole idea of manganese nodule mining started out as a massive CIA conspiracy to lie about a sunken nuclear submarine. [21] Many nasty stories about political figures were distributed during COINTELPRO. In cases like that you can scarcely tell what's going on because the stories were very plausible; by contrast there was the "Roswell UFO crash" where some low-level military guy was apparently given the advice to 'tell them anything' about one of those Mylar weather balloons used to spy on the Soviets. Some of the more popular conspiracy theories don't have fingerprints, but they certainly seem to have political utility to someone. Focusing on "second gunmen" in the JFK assassination is a distraction from the fact that Lee Harvey Oswald had a Communist background and was a defector to the Soviet Union, who plausibly might (or might not) have been ordered by Soviet authorities to carry out the attack. Focusing on explosives inside the World Trade Center might be a distraction from the question of whether an international military-industrial complex might have connived some agreement with bin Laden to encourage him to start decades of war. The "chemtrail" conspiracy idea distracts from the fact that there are chemical tanks on every airplane, i.e. fuel tanks, which emit geoengineering-worthy levels of unregulated sulfur dioxide that authorities don't crack down on (despite causing more than a thousand deaths annually) because it might cool the planet by about six months' worth of global warming. Etcetera. For every valid idea there are crazy interpretations (though never so often as in physics...), and it is even possible that behind every crazy notion is some primordial germ of valid truth. Wnt (talk) 16:21, 21 April 2018 (UTC)[reply]

C4

Any idea why C4 is called C4? Did there where yet in history bombs called C1, C2, C3 which weren't so effective like the 4th Generation or did it where called C4 since the invention of it? --Saegen zeugen des sofas jehovas (talk) 20:29, 18 April 2018 (UTC)[reply]

C4 is short for "Composition C4", part of the Composition C family of explosives (and yes, there was C1, C2 and C3). C4 is the only member of this family still in military service. Composition C was itself preceded by compositions B and A (see RDX). Someguy1221 (talk) 20:49, 18 April 2018 (UTC)[reply]

April 19

PC-rubber

does the "pc" in "pc-rubber" stand for polycarbonate? What is it exactly, a blend or a composite material with two separate layers? SpinningSpark 11:04, 19 April 2018 (UTC)[reply]

No. Polycarbonates (PC) are rigid thermoplastic polymers that may be transparent but are not like rubber. The commonest synthetic rubbers are abbreviated PCP (polychloroprene) rubber such as Neoprene for operating temperatures up to 95°C and EPDM (ethylene propylene diene monomer) for temperatures up to 130°C. DroneB (talk) 12:03, 19 April 2018 (UTC)[reply]

Are you sure of that? I'm seeing some sources that led me to believe it was the plastic that is meant,

"Yee et al. have reviewed the fracture behaviour of a number of two- or three-phase blends including PC-rubber and PC-ABS blends, with some success" in Rubber Toughened Engineering Plastics
"One can also note that the toughening mechanism in ternary blends is similar to toughening in impact resistant polymers. In the PBT–PC rubber blend, the pair PC–rubber in the process of melt blending forms the core–shell particles with rubber being inside." in Encyclopedia of Polymer Blends

Surely PBT, PC, and ABS all occuring in the same context just has to mean plastics? The context I came across this was while researching an article for Warren P. Mason who was trying to find a tougher material for sonar domes. My source says that before Mason these were made of pc-rubber but does not explain what that is. SpinningSpark 14:00, 19 April 2018 (UTC)[reply]

If PC-ABS (ABS is already a copolymer, BTW) is meant as a combination of polycarbonate and ABS, then it's more likely to be an inhomogeneous mixture, not a copolymer. A copolymer would be called PCABS, ABSC or something. This is a fairly common material commercial (Cycoloy is one brand) which is used for injection moulding of pieces like car exterior trim. It's used, rather than ABS, because it has good impact resistance at low temperatures. The microstructure of this stuff is streaky, like wrought iron. I don't know of any true copolymers (maybe a block copolymer?) of PC & ABS.

When you said "sonar dome", my first thought was Neoprene, which is widely used for them. However for the rigid internal structure of a non-magnetic sonar array, then I could see PC-ABS as being useful for it. Andy Dingley (talk) 15:00, 19 April 2018 (UTC)[reply]

That's a US government term for Neoprene, without mentioning any commercial brandnames. There's probably a federal law against Hoovering spilled Coke off the Naugahyde.

Polymer abbreviations are a total PITA (welcome to much of my working day). Every sub-field names its own polymers with the same acronyms. They're all "poly-" something. This one, given that it's a sonar dome, is likely to mean polychloroprene, which is a name, that no-one ever uses, for Neoprene.

It's a chlorinated rubber. Useful stuff, but it means I can't laser cut it. Unless I buy a non-chlorinated functional equivalent, which isn't as good. Unless I buy the Neoprene-branded one, which is UV-stable and weatherproof, and halogen-free: a Neoprene that's called Neoprene but is no longer neoprene. And the differences between "Plastazote" and "Evazote" (they're usually a copolymer, but it varies like crazy) are even worse. FML 8-( Andy Dingley (talk) 14:36, 19 April 2018 (UTC)[reply]

Thanks Andy, but I think you may get on better with a J-cloth than a vacuum cleaner for spilled drinks. SpinningSpark 17:03, 19 April 2018 (UTC)[reply]

1980s CIA flight? Andy Dingley (talk) 21:28, 19 April 2018 (UTC)[reply]

Southwest Airlines Flight 1380

During Southwest Airlines Flight 1380, I understand a woman was partially sucked out the window. Did they have trouble pulling her back in because of the pressure? If so, would breaking another window, thereby decompressing the plane, have made it easier to pull her back in? Would breaking that second window have caused other problems, barring others being sucked out of that one too?

Anna Frodesiak (talk) 11:22, 19 April 2018 (UTC)[reply]

Once a window has gone (although having someone blocking this will reduce it) the plane depressurises quickly. Even if they could, the crew wouldn't attempt to repressurise it, in case of hull damage.

Nor can you break a window. Those things are extremely strong. They're already holding such a force from the cabin pressure that nothing more you can practically do to them with hand tools is going to annoy them. Andy Dingley (talk) 14:51, 19 April 2018 (UTC)[reply]

This is the latest information that I can find: "While other passengers were able to pull her back into the aircraft, witnesses reported that she was in cardiac arrest as some aboard the plane attempted to revive her". Alansplodge (talk) 17:13, 19 April 2018 (UTC)[reply]

This guy managed to crack the inner window with a punch. SpinningSpark 17:14, 19 April 2018 (UTC)[reply]

That's just the inner window though. There are three layers (two on old aircraft), it's the outer ones which have the real strength. Andy Dingley (talk) 21:27, 19 April 2018 (UTC)[reply]

Has there been any report as to whether the victim was wearing her lap belt at the time? ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:44, 19 April 2018 (UTC)[reply]

The CBS report says one victim, wearing a lap belt (no idea how tight) was injured by blunt force trauma, went out through the window, was retrieved and given CPR, but died as a result of the trauma injuries. No second victim, and I've seen one victim named but not a second. Andy Dingley (talk) 21:42, 19 April 2018 (UTC)[reply]

Hi Andy. Ah, so she wasn't stuck from inside pressure pushing her outward the whole time, right? She was stuck from being in a tight place, forced there from the initial burst of depressurization moving her half way through the window. Once stuck, the plane then completely depressurized because she did not create a perfect seal. Does this sound right? And about the now-moot matter of breaking the other window, windows are strong, yes, that sounds right. A crack from a punch (as mentioned below) is a far cry from getting through the first pane to crack the outside pane enough to depressurize a plane. Anna Frodesiak (talk) 21:24, 19 April 2018 (UTC)[reply]

I have been closely following the official investigation by the NTSB: you can watch the Day 1 press briefing. Most notably, although the claim of a passenger being "sucked out" and "pulled back in" has been reported by the media very frequently, that claim has not yet been repeated by the official accident investigators.

Notably, during the emergency, the pilot of the aircraft did advise air traffic control that one passenger had fallen out of the aircraft. The pilot's radio call in that spirit is now officially on the record - but to evaluate the correctness of that statement, it should be clear that during the emergency, the pilot never independently went back to the passenger cabin to review the situation - she was busy handling the emergency in the cockpit, and was surely repeating "hearsay" from the passenger cabin.

In addition, the pilot also reported an engine fire; at the NTSB press conference, Chairman Sumwalt also indicated that there probably was never any actual fire - but that there are many technical reasons why a pilot might have seen incorrect instrument indications of a fire. Early analysis of the factual data is fraught with complexity, and the technical details are really complicated - which is why the NTSB will spend so much effort to evaluate, and separate, the "factual" from the "probable."

At this time, the only fatality appears to be one passenger, who was not sucked out of any window, but suffered severe, fatal blunt force trauma.

NTSB will continue to update its website with factual information. Chairman Sumwalt has proposed a reasonable timeline of 12 to 15 months for the complete report. It is probable, based on the timelines for other NTSB investigations of aviation accidents, that a preliminary report will be available within a few weeks. "Generally, a preliminary report is available online within a few days of an accident. Factual information is added when available, and when the investigation is completed, the preliminary report is replaced with a final description of the accident and its probable cause."

Nimur (talk) 21:05, 19 April 2018 (UTC)[reply]

The article says that another person died later. Bubba73 ^{You talkin' to me?} 21:18, 19 April 2018 (UTC)[reply]

Surely in the next few days, more statements and assertions will become public, and we can dispassionately evaluate all of the facts. At this time I only know of one fatality.

CBS News has just published an interview with a passenger who claims to have been involved in retrieving the passenger. We will only know whether these statements are completely accurate after a complete review of all the evidence.

Nimur (talk) 21:26, 19 April 2018 (UTC)[reply]

~~Here is a reference to a second passenger dying. Bubba73 ^{You talkin' to me?} 21:31, 19 April 2018 (UTC)~~ [reply]

Whoops, I misread it. Bubba73 ^{You talkin' to me?} 21:33, 19 April 2018 (UTC)[reply]

I believe that woman is the same, one-and-only fatality. Initial media reports, in classical fashion, double-counted a lot of the victims.

This brings up the important and grisly reality of first-responder discipline in a mass casualty emergency. From the textbook: ..."an ideal initial triage area should include... dedicated casualty recorders to identify, tag, register, and record initial triage". This problem is the exact reason why we use these unpleasant paper tags: you glue one to the deceased body, and you tear off the corner so you can hand it to the coroner. One tag, one fatality, no double-counting. This helps make sure that enough emergency responders are allocated to assist those victims who are still alive.

Needless to say, we all hope that our dear readers never need to use this knowledge.

Nimur (talk) 21:38, 19 April 2018 (UTC)[reply]

Speaking of CBS, it's ironic that this happened two days after a 60 Minutes report trashing Allegiant Air's safety record. Allegiant, for all its shoddy maintenance history, has apparently never had a fatality. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:36, 19 April 2018 (UTC)[reply]

Please cite evidence that the 60 Minutes piece was misleading or else don't use words like "trashing". --69.159.62.113 (talk) 22:57, 19 April 2018 (UTC)[reply]

Where did I say it was misleading? Quite the contrary - it scared me enough that if I ever had a chance to fly Allegiant, I would wait for another airline to come along. Just not Southwest. :) ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:39, 19 April 2018 (UTC)[reply]

You said "trash"ing, which means "to subject to criticism or invective; especially: to disparage strongly". It suggests malice or at least a strong expression of opinion, not responsible journalism. If that wasn't your intent, good, but I say it's a POV term be avoided unless that is what you want to imply. --69.159.62.113 (talk) 06:38, 20 April 2018 (UTC)[reply]

You should watch the report and you'll see what I'm talking about. Actually, they probably trashed the FAA as much as they trashed Allegiant. The report might be on the CBS website. ←Baseball Bugs ^{What's up, Doc?} carrots→ 07:11, 20 April 2018 (UTC)[reply]

Watching the report would not produce evidence that it was being misleading. If you mean they were, please cite evidence. If not, please stop using the word "trash". --69.159.62.113 (talk) 03:02, 21 April 2018 (UTC)[reply]

When isn't 60 Minutes misleading or just downright disgraceful in its work? Anna Frodesiak (talk) 23:04, 19 April 2018 (UTC)[reply]

Again, it can't be emphasized enough: anyone who knows all the facts about this accident can't talk to the press. For example, consider this statement from CFM. (Who are those guys? They're the people who make this little contraption). Straight from their press release: "By law, CFM cannot provide information about the accident or details related to it. You may contact the NTSB for updates."

In case you're wondering which law, that would be codified in 49 C.F.R. 830 - 831 and related sections; and usually further contractually specified in the form of a letter of understanding or a signed Party Form; and the information will become public later per 49 C.F.R. 801 and related rules.

What this means in practice is that any news you see in the mass-media is the result of an interview with someone who is categorically not an authoritative, reliable source. Interviews with witnesses are going to yield partial stories and their statements aren't yet vetted for accuracy. People who did know internal details of the investigation, and then published that information in the press, would get in trouble: in fact, in an unrelated accident and ensuing Federal investigation earlier this month, that exact scenario played out after some idiot loudmouth began releasing statements ahead of the official inquiry. If you value truth, fact, and accuracy, you need to exercise patience and let all the independent experts scrutinize the details.

When the preliminary facts are established, the first place you'll see an update is from the NTSB. After that, it's up to the mass media and their army of journalists to sensationalize those facts and sell copy.

Nimur (talk) 02:24, 21 April 2018 (UTC)[reply]

When the airplane window got broken by flying debris, the cabin pressure which is lower than atmospheric and is maintained artificially, dropped precipitously because it got sucked out by the outside air flowing around the aircraft. Such speeding air creates much lower pressure around like air flowing over a convex upper surface of an aircraft wing. The passengers survived because the masks got dropped from the ceiling and they started breathing through them. The masks made a breathing gas mix available to them. How those two males managed to breath through the masks and at the same time to have pulled the woman out of window, I cannot explain. The victim simply got sucked out because of the same force that drove the cabin air outside. It also probably cleared the cabin of everything else which was not firmly attached to the seats. AboutFace 22 (talk) 23:06, 19 April 2018 (UTC)[reply]

A startling number of passengers weren't wearing the masks properly. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:41, 19 April 2018 (UTC)[reply]

If your head gets sucked out of the window of a jetliner at cruising speed, sudden pressure loss is the least of your worries. The aircraft is flying at more than 500 mph, so the air is pushing on your head (roughly) that speed. The details are complex, but to a first approximation the force of the air goes up approximately with the square of speed, so your head will feel approxmately 100 times the force you feel if you stick your head out a car window at 50 mph. I speculate that the victim's neck would break against the window edge or be severely lacerated by any remaining glass. This also explains why two strong men required more than a few seconds to pull the victim back into the plane. Note that an airliner at cruising altitude must operate at high speed to avoid a stall in the thin air, so the pilots could not have reduced speed to lessen the force on the victim even if they had instantly learned of the situation in the cabin and even if they were not contending with a broken airplane.-Arch dude (talk) 00:16, 20 April 2018 (UTC)[reply]

As you say, the details are complicated, but note that the drag equation also includes the density of the fluid as a factor. The plane was at about 32,000 feet altitude, so the air pressure would have been maybe about 30% of what is is near sea level, and that factor of 100 times you mentioned becomes more like 30 times. Still plenty to cause a devastating injury, of course! --69.159.62.113 (talk) 06:48, 20 April 2018 (UTC)[reply]

New Physics? The more you think, the more questions arise. WWII fighter pilots used oxygen masks above 10,000 feet. If they did not, their judgment suffered and they passed out. Here the plane lost hermeticity at 32,000 - a standard cruising elevation and it took the pilot 10 minutes to bring it down to 4,000 feet or so. And in the meantime many things happen that required decision making, physical force and instinct. The victim was pulled out of the window by two gentlemen. Was she hanging out completely just barely holding the broken glass with her fingertips? I doubt the size of the window is large enough to allow an average person through, but this is my guess. In order to perform CPR the victim must have been positioned on the floor of the cabin. Could the mask tethers be that long to reach there? CPR is a demanding physical exertion. The nurse must have held her own mask on her face or someone was holding it for her. Many questions.

I just watched a silent movie "Girl Shy" with Harold Lloyd. One of the scenes is shot in a passenger train car. All benches are occupied except the one in the very front, on the left (as we see it). The benches accommodate two passengers only. On that bench in question sits a young lady, his heart's desire. She is next to the window. Since the train is obviously moving toward the viewer, she is in fact on the right side of the train. Harold performs a few silly attempts to find a seat elsewhere but is chased away by the passengers who occupy those. He has no choice but to sit next to the lady, but he is "girl shy" as we know. He gyrates himself toward her bench and at this moment the train enters a steep curve. The scene of the train on that stretch is shown from outside. It is obvious that the train is making a right turn. Harold loses his balance and he is thrown into that empty seat next to the girl. But she is on the concave side of the moving train, he is moving along the centripetal force which should not have been there. He should have flown in the opposite direction in fact, but of course we forgive the move makers. I think the description of what happened in the airplane that is given to us is equally confusing and unrealistic. AboutFace 22 (talk) 17:41, 20 April 2018 (UTC)[reply]

See TUC --catslash (talk) 19:25, 20 April 2018 (UTC)[reply]

That's for "young military pilots." Even the pilot of that flight was not in that category, although women have a better tolerance for hypoxia. AboutFace 22 (talk) 19:56, 20 April 2018 (UTC)[reply]

In February, we had a long discussion on the topic: loss of cabin pressure... and I linked to a few interesting videos and other resources.

For further reading, start with the PHAK, Chapter 17, Aeromedical Factors, and if you want more, you can read the complete textbook: Introduction to Aviation Physiology.

Nimur (talk) 23:15, 20 April 2018 (UTC)[reply]

The CPR was done (per the reports I've seen) by a firefighter. Who's in similar physical condition to a pilot.

There are walk-around oxygen bottles for the crew. It would be typical for one of those to be given to any passenger who's busy carrying out CPR.

Also there are plenty of cases of CPR being given by someone who themselves is suffering from anoxia. Anoxia is variable, dependent on physical condition and sensitivity to altitude, and often manifests itself mentally first. The CPR respondent could well have had a fuzzy head and felt lousy afterwards, whilst still being able to deliver CPR. Andy Dingley (talk) 14:38, 21 April 2018 (UTC)[reply]

In 1963 TV fiction, William Shatner opened an emergency exit door at an altitude of 20,000 feet while buckled in without suffering a fatal injury.Edison (talk) 03:53, 21 April 2018 (UTC)[reply]

Now we know the truth. Flight's 1380 engine was destroyed by a gremlin :-) AboutFace 22 (talk) 14:00, 21 April 2018 (UTC)[reply]

Plane of sky

What is a plane of sky in scientific context ? Found in the 4th reference in the 54509 YORP article. Googling returns results in computer games, but I didn't find a definition or explanation. -- Juergen 95.223.151.37 (talk) 23:26, 19 April 2018 (UTC)[reply]

That plane would be the one defined by (rather, approximated by) projecting the right ascension and the declination seen by the Earth observer as basis vectors; orthogonal to the "depth" axis or "distance from Earth," which is the orthogonal parameter that is measured by Doppler shift in radioastronomy. Here is a paper on the role of Doppler in NEO observations: The role of ground based RADAR in NEO Observation.... (2006). Here's another paper on using optical astronomy plane-of-sky measurements to constrain the radio or RADAR observations: RADAR Astrometry of small bodies....

I guess the most important thing to realize is that those other plots in our OP's reference - the ones that are NOT in plane-of-sky coordinates - are not "what the asteroid/NEO looks like": rather, those are Doppler plots, and must be interpreted by a RADAR algorithm to estimate a best-fit for the object's true shape. This conceptual hurdle is a very important stumbling block for new initiates learning to watch RADAR.

Wikipedia has an article on one such algorithm: SAMV for pulse/doppler, suitable for the highly-technical enthusiast readers. We also have the much better and more general article on Compressed sensing.

Nimur (talk) 00:04, 20 April 2018 (UTC)[reply]

A- ion in human cells?

Is there something like an A- ion in human cell fluids? Google is not very useful in these cases, since the results that pop up are lithium-ion batteries and blodd type a-. --Doroletho (talk) 23:46, 19 April 2018 (UTC)[reply]

In what context did you see something like this? Someguy1221 (talk) 00:43, 20 April 2018 (UTC)[reply]

I uploaded a screenshot of the book: [22].--Doroletho (talk) 02:40, 20 April 2018 (UTC)[reply]

Ah, thanks. The "A" does not refer to any particular ion, but rather it's a stand in for all large, negative ions. Those would mostly be proteins (the average protein is slightly negatively charged at neutral pH). It's possible they took "A-" from a common nomenclature for discussing acids, where "HA" represents the acid, and "A-" represents the deprotonated acid, and the acid could be anything because it doesn't matter for a particular discussion. Someguy1221 (talk) 04:11, 20 April 2018 (UTC)[reply]

Depending on the context, "A" could stand for "Acid" or "Anion", but really it's just a placeholder symbol. Chemistry has standard sets of "placeholder" symbols used in specific contexts (i.e. R for hydrocarbon, M for metal, X for halogen) see Symbol (chemistry) for some examples. --Jayron 32 10:58, 20 April 2018 (UTC)[reply]

I wouldn't trust the source the source you pulled that text from; looking at the figure, the intracellular ion balance is completely off - far too many anions - that would be very explosive. Klbrain (talk) 21:05, 20 April 2018 (UTC)[reply]

April 20

Quantum immortals

Assume we discover people who have far outlived the normal human lifespan and/or who survive a series of normally fatal accidents/injuries seemingly against all odds-- like the subject of the quantum immortality thought experiment. Would such a discovery constitute empirical confirmation of the many-worlds interpretation of quantum physics? (This is not a request for debate; I want to know whether I'm misunderstanding the concept of quantum immortality.) 169.228.147.129 (talk) 03:13, 20 April 2018 (UTC)[reply]

No. The chance that you personally observe someone who survives some event that was extremely likely to kill him, is actually unaffected by whether the many-worlds interpretation is true. Consider: If this interpretation is false, and there is only one world, then the chance that someone survives as 1-in-a-zillion event is 1-in-a-zillion. Repeated experiments will tend toward this rate. If the many-worlds interpretation is true, and there are as many worlds as possible quantum states, then the chance that you wind up in a universe where someone has survived a 1-in-a-zillion event is... still 1-in-a-zillion. If the null and alternative hypothesis predict the same outcome for an experiment, then that experiment is incapable of falsifying either. Someguy1221 (talk) 04:01, 20 April 2018 (UTC)[reply]

Thank you, that clarifies things a lot. 169.228.147.129 (talk) 04:04, 20 April 2018 (UTC)[reply]

There's a reason why the various Interpretations of quantum mechanics are called interpretations and not theories: As noted by Someguy1221, they are not testable or falsifiable, and as such, do not occupy the same realm as formal theory. Some physicists even get annoyed by the existence of such interpretations, notably N. David Mermin's exhortation (often misattibuted to others such as Murray Gell-Mann or Richard Feynmann) to "Shut up and calculate!" --Jayron 32 11:03, 20 April 2018 (UTC)[reply]

You can't diagnose quantum immortality in anyone but yourself; however, the concept suffers from some flaws from the perspective of anyone who has ever been knocked unconscious, since why aren't you in the world where you never lost consciousness...? Cf. atman; there is no quantum-based necessity for one single individual to survive to fulfill this many-worlds requirement, even if it is one. This is without even getting into speculations about the quantum nature of consciousness itself.... Wnt (talk) 00:07, 21 April 2018 (UTC)[reply]

Radiation-loving species

So, what's the deal with https://www.scientificamerican.com/article/radiation-helps-fungi-grow/ ? I haven't been able to find any articles about this fungus not from 2007. Have we discovered more of such radiation-loving species? Or is there some totally mundane explanation not involving radiation? 93.136.60.4 (talk) 03:34, 20 April 2018 (UTC)[reply]

I can't find any papers that reference new species beyond what was in the original paper, though I did find many recent papers about melanized fungi that are merely resistant to ionizing radiation, but that was suspected long before 2007. The phenomenon is still heavily studied, see [23]. But the interest seems to be in understanding the mechanism, rather than isolating new species. Or people have been trying to isolate new species, but they never report the attempts because they never succeed. Someguy1221 (talk) 03:55, 20 April 2018 (UTC)[reply]

That's a little too technical for me. So they're not really thriving in radiation, they'll just survive in a low-medium radiation environment, and high enough radiation will wipe them out just like other known lifeforms? 93.136.96.61 (talk) 18:06, 20 April 2018 (UTC)[reply]

They're thriving in the sense that a little bit of radiation makes them grow faster. But yes, a lot of radiation, and they still die. Though for these little guys, "a lot" is way more than what ordinary organisms could tolerate. Someguy1221 (talk) 19:03, 21 April 2018 (UTC)[reply]

On measuring weight via force

When I stand on my analog bathroom scale and remain still, the scale displays a steady weight. If I move my arms up and down while standing on the scale, the scale displays a variable weight. Reddit explains this is because the bathroom scale is actually measuring force not mass.^[1]

My question is if I found a balance scale big enough to stand on, did so, and had kilogram weights used to balance balance the scale would any arm movement impact the balance?

Similarly, is there an approach for determining the mass of a person that is immune to these perturbations?

Thanks in advance. I find this reference desk a delightful source of information and knowledge. I enjoy all the great information and discussion that takes place here.

128.229.4.2 (talk) 12:47, 20 April 2018 (UTC)[reply]

^ https://www.reddit.com/r/askscience/comments/21hy1o/if_im_standing_flat_on_a_scale_and_swing_my_arms/. {{cite web}}: Missing or empty |title= (help)

I am not aware of any mass determination method that does not involve measuring a force (be it the inert or gravitational mass). Any such method is bound to be fooled by weight-swinging, as adequately explained by the redditors. I do not understand the first question. Tigraan^{Click here to contact me} 13:07, 20 April 2018 (UTC)[reply]

Ok, thanks Tigraan. To clarify the first question, my bathroom scale looks like this, and by balance scale I'm talking about a scale like this. I didnt know if differences between the two scales might change things. 128.229.4.2 (talk) 13:25, 20 April 2018 (UTC)[reply]

Both of these operate by measuring the force of gravity on an object, by countering that force against another force. In the case of the bathroom scale, the opposing force is the force of a spring, governed by Hooke's law; the roughly linear response to compressing a spring allows one to make a simple bathroom scale; double the force, double the compression, turn the dial twice as far. But it's still using force. The second scale, the balance-type scale, takes advantage of torque, in this case if the cross arms are equal length from center to the pan, then equal forces on the pans will exactly balance, because the opposing torques will cancel out. This is still using the force of gravity; just using it twice. Any time you introduce an outside force to the system (such as waving your arms around), you're going to throw it off, since no scale can tell the difference between force of gravity and other forces. They're all just force-measuring devices. --Jayron 32 13:42, 20 April 2018 (UTC)[reply]

Cool! Thanks Jayron32! 128.229.4.2 (talk) 14:09, 20 April 2018 (UTC)[reply]

Not exactly a different principle, but the way to correct for these pertubations is simply measuring the average force over time. If you integrate the force on a scale over 30 seconds, you can swing your arms all you want, but as long as you don't step off the scale, the scale can still calculate your mass very accurately (even a 10 seconds measurement is pretty good). - Lindert (talk) 14:40, 20 April 2018 (UTC)[reply]

As Lindert notes, random arm waving would be a classic example of noise; which can be reduced by common noise reduction techniques; all of which rely on averaging a bunch of measurments over a long period of time; over time the signal to noise ratio generally improves with a greater sampling rate. --Jayron 32 16:05, 20 April 2018 (UTC)[reply]

Yes there is a way to measure mass that will be somewhat immune to arm waving. Suspend a large mass on a string. Measure its position. Now move closer to it. Measure its position again. Wave your arms. No effect. The gravitational force between you and the sphere is not much affected by you waving your arms in the plane tangential to the line joining you and the sphere. There are many other problems of course. Greglocock (talk) 17:47, 20 April 2018 (UTC)[reply]

The waving of your arms is likely to generate sufficient air currents to perturb the position of the sphere several orders of magnitude greater than the movement due to gravitational attraction to you. --Jayron 32 17:55, 20 April 2018 (UTC)[reply]

I like this idea. Indeed there are problems, as Jayron expands, but I liked it nonetheless. I was thinking in this sort of direction as well. Not gravitation, but I was thinking that if mass is equal to density x volume, volume here could be gathered by water displacement. Finding the density of a person might be more complex? Or might just involve a tool(s) I'm not familiar with. 128.229.4.2 (talk) 19:19, 20 April 2018 (UTC)[reply]

Is it known if retargeting ICBMs would take longer if you want an explosion near the maximum possible altitude?

They can reach about 8 kilometres per second so the maximum possible altitude is very high. Sagittarian Milky Way (talk) 16:16, 20 April 2018 (UTC)[reply]

Question does not make sense. One does not want the warhead to go off at max altitude. It diminishes the destructive power at ground level. Re-targeting would take time because ICBM's are pre-targeted (mostly). The ICBM's also have accelerometers etc to ensure that they don't go off prematurely in the event of a bad launch, which could amount to a home goal. The launch teams as far as I know have no way of overriding these safety precautions to allow the warhead to go off at max apogee. If some editor knows better, you can bet that they will correct me in the next post. Aspro (talk) 18:44, 20 April 2018 (UTC)[reply]

Well, it depends on what you're trying to achieve. If you want to kill the most people, then you want a burst at some modest altitude. But if your goal is maximum disruption for fewest deaths, then maybe you're going for a nuclear electromagnetic pulse, which could indeed mean you want to detonate at a high altitude (though as 209 says below, still not "maximum" altitude). --Trovatore (talk) 03:03, 21 April 2018 (UTC)[reply]

Further, there is no "maximum possible altitude" for "ICBM." There are many different types of ICBM missiles. They are designed and fueled to just barely make it into orbit and then follow a ballistic path back to Earth. Smaller ones don't make it to orbit at all. Larger ones not only have the ability to make it into orbit, they are used without warheads to put things into orbit. So, they can obviously reach an escape velocity for an undetermined maximum altitude as it floats off through space. 209.149.113.5 (talk) 18:54, 20 April 2018 (UTC)[reply]

Presumably the interest regards targeting aliens, asteroids, uppity space prison inmates, etc. Then escape velocity is over 11 km/s which means the things as described are tragically unsuited for many purposes. And with so much fuel devoted to climbing it seems inevitable that retargeting must suffer for a lack of reserve. Wnt (talk) 00:04, 21 April 2018 (UTC)[reply]

Back during the days of MAD, all of the possible strategic targets were known in advance and the appropriate parameters were precomputed for each target, so retargeting was a matter of setting these precomputed parameters for the new target. Because the time of flight for an ICBM is quite long, setting a new target in real time makes no sense as the target will have moved. The situation for IRBMs and theater ballistic missiles is a bit different. -Arch dude (talk) 02:51, 21 April 2018 (UTC)[reply]

Neither Peak nickel nor Peak lithium article?

Given the apparent development of the vehicle fleet towards electric vehicles, wouldn't that lead to depletion of possible battery components like lithium or nickel? Or is our back covered for so many decades that's not worth worrying? According to the links in the peak oil article, lots of materials have a peak that can be allegedly calculated. Aren't concepts like 'peak nickel' or 'peak lithium' notable? --Hofhof (talk) 18:30, 20 April 2018 (UTC)[reply]

The general agreement among reliable sources seems to be that "peak lithium" is not a thing. --Jayron 32 18:42, 20 April 2018 (UTC)[reply]

yes, but even if people claim it won't happen, doesn't that make the concept notable, since people are discussing it? --Hofhof (talk) 18:52, 20 April 2018 (UTC)[reply]

Unlike oil or other hydrocarbons, nickel and lithium are elements. The quantity of nickel, lithium, or any other pure element on earth is likely to stay constant, isn't it? ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:06, 20 April 2018 (UTC)[reply]

However the economically recoverable amount may not. See peak phosphorus, for example. Also we are currently burning quickly through our conveniently obtainable helium, which is currently massively underpriced due to the sell-down of the National Helium Reserve. --Trovatore (talk) 20:14, 20 April 2018 (UTC)[reply]

Then, what's all the fuss about Peak copper?Hofhof (talk) 20:27, 20 April 2018 (UTC)[reply]

Lithium#Reserves has some relevant comments, and Nickel#World production could be expanded to do the same for Nickel. Klbrain (talk) 21:54, 20 April 2018 (UTC)[reply]

There's nothing stopping the OP from either creating those articles or creating redirects to portions of other articles. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:56, 20 April 2018 (UTC)[reply]

See [24] and original article [25]. The difference between batteries and fossil fuels is that you consume energy in fossil fuels, but you merely need to use elements in batteries, which means that there are endless ingenious variations possible. Wnt (talk) 00:01, 21 April 2018 (UTC)[reply]

Are depressed people more likely to drink alcohol, or does heavy alcohol consumption make people more likely to be depressed?

In other words, does depression make people more likely to drink alcohol? Or does drinking alcohol (a depressant) make a person more depressed? Also, if a depressed person takes a stimulant, like caffeine, can that treat the person's depression? SSS (talk) 22:44, 20 April 2018 (UTC)[reply]

Both. Depression is not a condition. Depression is a wide range of conditions with many different causes. Alcohol doesn't have one effect. Alcohol has many different effects for many different people. — Preceding unsigned comment added by 2600:1004:B158:83F3:4A0:F30A:43F7:3114 (talk) 23:00, 20 April 2018 (UTC)[reply]

Do you have any references? SSS (talk) 23:16, 20 April 2018 (UTC)[reply]

You could start with Depression (mood)#Factors and Alcoholism#Causes. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:38, 20 April 2018 (UTC)[reply]

Does personality (in normal people) has to do something with genetics?

How much genetics influence on our personality? Do we expected to be like our father or mother or their relatives based on the genetics? If we look at dogs, then almost everyone knows that there are dog races more calm as well as less calm, and it strengthens my assumption that there is a relation between personality and genetics. But I'm not sure what accepted widely about it in science world and I'd like to know about it. 93.126.116.89 (talk) 22:51, 20 April 2018 (UTC)[reply]

See nature versus nurture. 2600:1004:B158:83F3:4A0:F30A:43F7:3114 (talk) 23:03, 20 April 2018 (UTC)[reply]

There is some evidence that personality may also be affected by the gut microbiome see:[26][27]. Richerman (talk) 23:18, 20 April 2018 (UTC)[reply]

Even identical twins tend to have distinguishable personalities. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:36, 20 April 2018 (UTC)[reply]

Even the inseparable ones tend to not share wives for instance. Non-identical lives, non-identical humans. Sagittarian Milky Way (talk) 02:18, 21 April 2018 (UTC)[reply]

“Most children resemble the brother of the mother.”

Is there any scientific support to the written in the Babylonian Talmud Baba Batra (110a)? There are two translations to the text that was written originally in Aramic language: 1st translation: “Most children resemble the brother of the mother.” or the 2nd translation: “sons usually inherit the traits of their mother's brothers” (The Encyclopædia of Sexual Behaviour, Volume 2 p.583). Is there any scientific support this claim? 93.126.116.89 (talk) 23:37, 20 April 2018 (UTC)[reply]

Anecdotally, I can tell you that I am a lot like my father in both personality and appearance, and nothing like my mother's brothers. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:40, 20 April 2018 (UTC)[reply]

It's written there "most" so it can be 51% and more, you can be from that minority, that's why I don't look at in a personal examples). 93.126.116.89 (talk) 00:17, 21 April 2018 (UTC)[reply]

"Most" would need to be a lot more than a bare minimum majority. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:31, 21 April 2018 (UTC)[reply]

Brothers and sisters share 50% of their genes, as do mothers and sons, so the resemblance is 25%. That said, (a) a gene might not affect a woman in the same way, (b) social prejudices may not permit recognition if it does, and (c), most interestingly, there are some sex-linked traits on the X chromosome. So suppose a male grandchild suffers a trait with X-linked recessive inheritance like hemophilia A. Then his mother must be a carrier; in all likelihood she does not have the disease because she has another X chromosome. She in turn inherited that gene either from her mother (who would appear unaffected) or else from her father (who would be affected). As we know she must be a woman, she necessarily inherited one X from each of her parents so the odds of either being a carrier/affected should be the same. If her father was affected, her brother (the child's uncle) cannot have inherited the gene from him; but if her mother was a carrier, then her brother had a 50% chance of being affected depending on which X he received. Well... that means the grandfather and uncle each had 25% overall chance of being hemophiliacs, given that the child has the trait. Which gets us nowhere new. But ... if we suppose the condition is something fatal (and hemophilia may be) then the grandfather was less likely to have had it because then he might have died and not passed the condition on if he had. If it is truly lethal we know it hasn't reared its ugly head in the child's direct line of descent, and only uncles could have had it. It is, therefore, at least conceivable that someone with a particular interest might have penned this verse, but I can't tell you. Oh, and note that Tay-Sachs disease is not on the X, so that's not it. Wnt (talk) 23:56, 20 April 2018 (UTC)[reply]

April 21

experience day on breast pumps (for milk)

Hello there. I work in a Shop for Sex Toys. I am wondering why there is an "best before..." day printed on the packet of the breast pumps for milk. There is nothing more inside as in a packet of breast pumps for breast enlargement or penis pumps - and the last 2 things have no date on them. The plastic even feels the same of all 3 products, so I doubt that it is because the material may get weak. I can't imagine what may happen if you use breast pumps which are out of date. Any Idea? The day is also printed on pumps which doesn't include the bottle where the milk flows inside. I doubt first that it is because of that bottle, but seems to be not the reason. --Saegen zeugen des sofas jehovas (talk) 03:11, 21 April 2018 (UTC)[reply]

I added the link for you for those who are unsure what a human breast pump is. SSS (talk) 04:57, 21 April 2018 (UTC)[reply]

Googling the subject, one item that came up is this page with several opinions.[28] I've seen expirations on medical equipment before. The points raised about the parts deteriorating and/or accumulating residue sound reasonable. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:19, 21 April 2018 (UTC)[reply]

However there is consensus [29] that pumps for breast enlargement are ineffective and possibly harmful. DroneB (talk) 19:37, 21 April 2018 (UTC)[reply]

Yes, I was talking about breast pumps for producing milk from an already-lactating woman. The other items are fraudulent. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:52, 21 April 2018 (UTC)[reply]

Calories

This paper says that recovered anorexic patients required more calories to just maintain a healthy weight than people who were never anorexic. It doesn't explain why though. Does anyone know? Is the claim this paper makes even true at all? — Preceding unsigned comment added by 46.149.85.156 (talk) 17:22, 21 April 2018 (UTC)[reply]

Eh? The abstract explicitly compares restricting anorexic patients and bulimic anorexic patients, not restricting anorexic patients and people who were never anorexic (that might imply a normal population). Big difference. SSS (talk) 18:23, 21 April 2018 (UTC)[reply]

This article is published in 1991. So, it's likely outdated. I would say that the information is true, because it is based on observation. But the information may be outdated. Earlier studies are useful in understanding the accumulation of knowledge throughout time, but are not that relevant today. I would suggest limiting your search results to at least 2010. SSS (talk) 19:13, 21 April 2018 (UTC)[reply]

Think that caloriofic intake discussions can be a bit misleading. If someone has very low muscle mass, then what they need to recover is not simply calories per sa . The calories need to come from both carbohydrates and protein in the right ratio. During the end of the second world war, the US forces could not understand why the death-rates of the liberated inmates of concentration camps continued to die, despite being more fed bread than they have every had for some time. Their liberated US POW's from Japan also had a greater mortality more than any of the allied forces. With the benefit of hindsight it is obvious why. The war was costing the US millions of dollars per hour ( not per day). So wanting to be economic they provided the cheapest food. The US doctors that recommend this ( for the purposes of career advancement) should hang their heads in shame for for the number of US personnel that died from their self interested recommendations... Whoops. Nearly missed the point. If an individual is emaciated with low muscle mass, then gets fed loads of carbohydrate, the body needs some protein in the diet in-order to metabolise it. If it is not available in the diet, the body get the protein from the individuals muscle mass. For someone someone who is already emaciated - that results in death. People that have been diagnosed with anorexia need more protein. Aspro (talk) 22:13, 21 April 2018 (UTC)[reply]

Gallien kreuger speakers

How do gallien kreuger get such a good low frequency response from their very small sealed speaker cabinets.? 86.8.201.80 (talk) 19:33, 21 April 2018 (UTC)[reply]

Which speakers? what is their frequency response? how does it compare with whatever you are using as your baseline? Greglocock (talk) 21:44, 21 April 2018 (UTC)[reply]

The speakers they use in their bass combos and standalone cabinets. Look at the website. Im talking bass guitar response. They seem far better tan any other stuff advertised as bass amps, 213.205.242.225 (talk) 22:06, 21 April 2018 (UTC)[reply]

Never heard of them.

Do they? Is this true?

Do they deserve it? Are these reviews accurate?

How "small" are they?

The problem of a small speaker cabinet is to move a large volume of air accurately. This requires either a large diameter driver (a large area) or else a high speed driver with a long throw (to move the same volume in the same time, as volume is the product of area and length). The second is difficult, but not actually that necessary to be a "good" speaker. Most speaker comparisons are just between "bad" and "middling". To be a "bad" speaker, the usual problems are a speaker case that is acting as a diaphragm itself (not rigid or massive enough) or a ported design where the path length through the port is short enough to allow destructive interference of the sound waves. This is a sealed design, so the first is the problem, and that's solvable. The first "good" speakers I ever bought (early '80s) were a pair of 'Musician Bonsais' which were hand-made in a shed on the side of Liverpool University, by one of the lab techs there, using a new material of a dense cement fibre board to make a robust housing for unusual long, thin drive units with no crossover. Very early '80s, sounded awfully clinical, but an excellent stereo image (and good for playing awful early '80s productions that were mixed on similar studio monitors, like Bolts.).

A further problem (the problem of decent hi-fi in sensibly sized speaker cabinets through the '70s) is to avoid reflections inside the cabinet emerging through the speaker cones again. This is solvable by adequate cabinet sizes, damping material inside (wedges of light foam, not just packing with rockwool, as that turns into its own reflective surface). One of the best speaker designs to avoid this were the Linn Isobariks, which removed it altogether at the cost of twice the build cost and also an amplifier load which couldn't be driven properly by most high-end amps and instead needed a specialist (and dirt-cheap) NAD 3020 to do it. The Isobarik secondary drive unit in its sealed box turned into a mechanically-loaded inductive load.

In the end though, it comes down to cost. Speaker design isn't rocket surgery, but the build cost and the cabinet size just refuses to get any smaller, no matter what smarts you throw at it. Maybe they just do the obvious stuff we've known since the mid-'80s, but they don't cut the usual corners on it?

For anything more, please cite model numbers and reviews. Andy Dingley (talk) 22:08, 21 April 2018 (UTC)[reply]

[1] Bayard Webster (1982-08-17). "Infanticide: Animal behavior scrutinized for clues to humans". The New York Times. Retrieved 2008-01-18. {{cite news}}: Italic or bold markup not allowed in: |publisher= (help)

[2] ttps://www.reddit.com/r/askscience/comments/21hy1o/if_im_standing_flat_on_a_scale_and_swing_my_arms/. {{cite web}}: Missing or empty |title= (help)

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