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April 13

Why does it take so long to determine the cause of death?

I was looking at Dolores O'Riordan's article and the coroner's office still hasn't published its report as to the cause of death. It's been almost three months. Why does it take so long to determine the cause of death? Is the reason scientific? Do certain tests take that long? Thanks. Basemetal 02:38, 13 April 2018 (UTC)

The toxicological report typically delays things the longest. The individual tests don't generally take that long, but there may be many tests desired, the coroner may decide on new tests after he receives the results of previous tests, he may want to have the tests repeated at a different facility, or he may want to consult with another pathologist about the results. On top of all of this, many testing centers have a constant backlog before they can handle new requests. [1][2] Someguy1221 (talk) 03:00, 13 April 2018 (UTC)

These sources [3] [4] note that there was little chance the coroner would have publicly released any further findings before April 3rd no matter when they received them. However they may have released these to the family, who would have been free to publicly release it themselves. Of course April 3rd has come and gone. A quick search finds this [5] [6] that the hearing was removed from the schedule with no reason given and no new hearing date scheduled. You may be interested in the sources [7] [8] for an overview of how things work in the UKEngland and Wales. Nil Einne (talk) 10:36, 13 April 2018 (UTC) 13:14, 13 April 2018 (UTC)

<WP:OR warning> I sleep with someone who works in the industry, and can confirm that, unless there is an emergency "rush" situation that pushes a forensics case to the front of the line (this usually requires a legal judge's order), cases are worked in the order received, and a backlog of 2-3 months is standard, and longer is not unusual. The test itself can be completed in a day or two, easily. The problem is there are probably many other cases in line before that one. --Jayron32 12:27, 13 April 2018 (UTC)

Actually on second thought, although the site doesn't seem to mention the info is specific to England and Wales that I can see, considering the situation in Scotland is a little different (Coroner) the info possibly only applies to England and Wales. It may also apply to Northern Ireland, but I'm not so sure. The Manchester site info is obviously specific to there, but I don't see any reason to think they're an outlier in terms of time frames. I've modified my answer accordingly Nil Einne (talk) 13:14, 13 April 2018 (UTC)

Thanks. Basemetal 14:50, 13 April 2018 (UTC)

Is dark matter segregated to the outskirts of galaxies? If so, why?

I was reading article Dark matter. Two facts about the hypothesized dark matter concept puzzled me: (1) that it accounts for more than 80% of the mass of the observable universe and (2) that it seems to be mostly confined to the outer edges of galaxies. (This sort of makes sense to an ignoramus like me, after all if it was distributed the same as visible matter, it would be all around us and the laws of gravity as applied to everyday objects here on earth would already have had to take it into account) But is that correct? Have I understood things correctly or not? Basemetal 15:01, 13 April 2018 (UTC)

The problem with Dark matter is mostly a linguistic problem rather than anything else. Here's a list of things that we know we know about the phenomenon that we have unfortunately named Dark matter. 1) The force of gravity we know to be acting on large-scale objects in the universe like galaxies is about 80% stronger than is only about 20% of what we can account for using existing models. 2) there is no #2. "Dark matter" is the collective name for all of the mechanisms that have been proposed to account for that. Here is a pretty good explanation from NdGT, which is concise and explains the problem. These aren't really "facts about the hypothesized dark matter" that you listed, instead it would be better to think about them as "hypothesized facts about dark matter". That is, proposals for what it might be. The might there is pretty well untested, however, as yet. This is a longer explanation from him as well, where he eliminates what we know it isn't, and why we know it isn't those things. --Jayron32 15:10, 13 April 2018 (UTC)

If the estimate is 80% dark matter and 20% observable matter then wouldn't it because the gravity is 5 times stronger (meaning 400% stronger) than expected from the observable matter? PrimeHunter (talk) 16:19, 13 April 2018 (UTC)

Yes, you are correct. I have ammended my original statement to be more precise in my language. About 20% of the gravity has known causes. About 80% cannot be accounted for. --Jayron32 16:31, 13 April 2018 (UTC)

Sigh. This (or the videos) still don't answer my question. It seems to be saying my question is not worded properly. That I should not be talking of "dark matter" as a thing or something. Lots of people do that, so maybe someone will humor me and just answer my question. Note that article Dark matter also sometimes phrases things as if dark matter was a "thing" (e.g. "The arms of spiral galaxies rotate around the galactic centre. The luminous mass density of a spiral galaxy decreases as one goes from the centre to the outskirts. If luminous mass were all the matter, then we can model the galaxy as a point mass in the centre and test masses orbiting around it, similar to the solar system. From Kepler's Second Law, it is expected that the rotation velocities will decrease with distance from the centre, similar to the Solar System. This is not observed. Instead, the galaxy rotation curve remains flat as distant from the centre as the data is available. If Kepler's laws are correct, then the obvious way to resolve this discrepancy is to conclude that the mass distribution in spiral galaxies is not similar to that of the Solar System. In particular, there is a lot of non-luminous matter (dark matter) in the outskirts of the galaxy."). Again, my question is this: When you read that the estimate is 80% dark matter and 20% observable matter it does not mean that the earth, the solar system, etc. are composed to 80% of dark matter, correct? Because the laws of gravity work well enough "down here", correct? They don't need to be fixed "down here", correct? Therefore if something needs to be fixed it is only at the scale of a galaxy, correct? So if "dark matter" is just a way to fix the missing 400% 80% of gravity, it is only needed "out there", not "down here", correct? So, somehow you want it "out there" and not "down here", correct? Whew. Thanks for any clarification. Basemetal 17:52, 13 April 2018 (UTC)

Yes, the effect is diffuse enough to be inconsequential on human-sized scales, and is only evident on galaxy-sized scales. Which is to say the effect is the same, but its detectability is small enough to be calculable, but not measurable, i.e. insignificant. Lots of astrophysical concepts are like that, i.e. metric expansion of space. The deal with "dark matter" is that the forces holding galaxies together at the rate at which they rotate can't explain why they don't blow apart: if you take a galaxy-sized object, start it spinning at galaxy-spinning rates, and apply the requisite amount of attractive force that galaxy has based on its observable mass, the math says the galaxy would fly apart. So there is some other force holding the galaxy together. The cause of that force is what we have called "dark matter". Of course, if "dark matter" works "out there", it also works "down here" in the same way that quantum mechanics works on all scales; its just that the math produces the same results as the simplified theory, so we can ignore it on our scales (that is to say, if you add dark matter physics to earth-based physics problems, you can perhaps calculate a negligible change in expected motions, but not on a scale that any measuring device known to man could detect). --Jayron32 18:06, 13 April 2018 (UTC)

Yes I understand why it is needed. But why is the effect inconsequential on human (or even solar-system size) scale? Simply invoking scale doesn't seem to explain things adequately. At galaxy scale it is a huge effect. It is 80% of gravity. If it is 80% of gravity at the scale of a galaxy, then why isn't it 80% of gravity at the scale of the solar system. These are percentages remember. Scale has nothing to do here. Why are the percentages different at the scale of a galaxy from the scale of the solar system? (You're probably right that "lots of astrophysical concepts are like that", but that's not really an explanation, that's just like saying, well, yes, though). Basemetal 18:44, 13 April 2018 (UTC)

It's because gravity is quite a weak and long-range force, and because dark matter seemingly has no other interaction (magnetic, electrostatic, chemical, etc.) with either "ordinary" matter or with itself. Consequently, while ordinary matter readily concentrates itself into dense stars and planets (etc.) to which we can be quite close, dark matter seems to be spread out fairly evenly through the whole volume of a galaxy (which is mostly otherwise "empty space") in a diffuse cloud which extends even beyond the detectable limits of the ordinary matter. {The poster formerly known as 87.81.l230.195} 2.218.14.51 (talk) 19:13, 13 April 2018 (UTC)

I see. So you're saying the density of dark matter across the galaxy is uniform but the ratio of dark matter to visible matter is lower in the solar system (say) than in the galaxy as a whole because visible matter tends to concentrate into clumps such as stars, planets, etc. while dark matter does not, so in those areas where solar systems are the ratio of dark matter to visible matter is lower than in the galaxy as a whole whose volume is made mostly of empty space (except for all that dark matter, that is). Is that what you're saying? Did I get this right? Now the Solar System has a total mass of 1.0014 Solar masses while the Milky Way has a total mass of 0.8 to 1.5×10¹² Solar masses. How do I calculate the total mass of dark matter in the Milky Way and in the Solar System. Article Milky Way gives something called "Dark matter density at Sun's position". Why do they need to specify "at Sun's position" if the density of dark matter is uniform? And what units is it in? Thanks. Basemetal 20:53, 13 April 2018 (UTC)

((edit conflict) Just noting the question above me was a little different when I actually wrote this post) Since dark matter does not aggregate with itself or baryonic matter due to the lack of electromagnetic interactions (which means, no binding, no scattering, no friction, passing straight through objects) it does not collect around a star. The dark matter dominates the galaxy but it is diffuse. Light matter is not so diffuse - like baryonic matter itself, there are little clumps with extreme density, and then a whole lot of nothing. That is, you have (relatively) tiny stars with immense mass, and then lightyears of mostly-empty space. The earth and the sun are incredibly dense compared to most of of space, and relatively close together to boot, so their relative motion is dominated by their own mass. Overall, dark matter tugs on the sun and the earth stronger than either tugs on the other with what should be a significant force, but since most of it is far away, the earth and the sun experience virtually the same tug. Think about the earth and the moon, and imagine the sun was completely dark, but we could somehow still see the moon. Could you tell the earth-moon system is orbiting the sun, simply from the motion of the moon about the earth? It would be extremely difficult, since the motion of the moon relative to the earth is caused almost entirely by the mass that is nearest to it - the earth. Local effects dominate local measurements. However, if you were to somehow be able to see all the other planets, you would notice something funny. The planets are far from each other, and rotate about their approximate mutual center of mass, but they are moving far too quickly. Anyway, dark matter is not even hypothesized to be segregated to the edges of the galaxy - it's commonly believed to be more concentrated in the center like everything else (see dark matter halo). But since there's basically no friction to slow it down and draw it in, it would hypothetically maintain a much broader distribution as galaxies formed, resulting in the ration of dark-matter/light-matter to get larger and larger as you move out from the center of a galaxy. Someguy1221 (talk) 21:05, 13 April 2018 (UTC)

To your question of calculations, you could take the formulas at the article I linked, and plug in values for a given model to find out the density in the solar system, and then from there calculate say the total mass in a sphere centered on the sun with the radius of the earth's orbit, which by the shell theorem will allow you to calculate how much of the Earth's orbital speed is caused by dark matter. It will probably be many orders of magnitude smaller than the sun's contribution, or at least one would hope. Someguy1221 (talk) 21:08, 13 April 2018 (UTC)

That calculation is done here. --catslash (talk) 21:17, 13 April 2018 (UTC)

See Dark matter halo. The density of dark matter goes down with distance from the center of the galaxy - but slower than for normal matter so it spreads out further. And there doesn't seem to be concentrated clumps of dark matter, though it probably has some structure it is of a much fuzzier kind. +um sorry I see Someguy1221 says this all above. Dmcq (talk) 21:43, 13 April 2018 (UTC)

Yes the calculations were pretty much already done in Dark matter halo and in Catslash's link. For the Milky Way visible matter is about 9 x 10¹⁰ solar masses and dark matter is between 6 x 10¹¹ and 3 x 10¹² solar masses. So let's say the ratio of dark matter to visible matter is of an order of magnitude between 10 and 10² (at least according to those figures; the text of the article says 95% of the mass of the Galaxy is believed to be dark matter; compare that with 80% for the whole of the observable universe). As to the Solar System: Catslash's link gives 2.3 x 10¹² kg of dark matter within the earth orbit (that's not the whole of the Solar System but ok) while the mass of the Sun is about 2.0 x 10³⁰ kg (this can be assumed to be the whole of the mass in that orbit as a first approximation, as the mass of all the planets, etc. accounts for only about 0.0014 solar mass). So the ratio of dark matter to visible matter in the Solar System is of an order of magnitude of about 10^-18. Clearly minute. Now I get it. Thanks everybody. Basemetal 23:54, 13 April 2018 (UTC)

Hmmmm... that 10¹⁸ ratio is impressive. However, Planet Nine at aphelion is at 1200 AU, so there the ratio should be 10⁸. Moreover ... the ratio would appear to be hypothetical, as dark matter hasn't been observed. The Sun does exert gravity, and so it seems at least conceivable that the Sun and other stars might have a little more dark matter in their neighborhood, a few orders of magnitude maybe?, than the surrounding empty space. (Hmmm, then again I suppose there are double stars with predictable masses and orbital periods that argue to the contrary, though I haven't looked into it) I wonder if some of the difficulty in finding the planet might possibly result from not taking a possible dark matter contribution to its orbit into account? Wnt (talk) 02:40, 15 April 2018 (UTC)

Youhave to have some sort of interaction like friction to get a gas to condense around a massive body, otherwise the molecules would just go out again in orbits at least as far as however far away they start. And there is a big halo because the dark matter doesn't seem to interact much with anything, it certainly isn't condensing at the scale of individual star systems. Gravity in itself can cause clumping but not at that scale so swiftly (by that I mean since the big bang). In fact I'm surprised it has clumped so much even at the scale of galaxies. Dmcq (talk) 10:46, 15 April 2018 (UTC)

Chemistry Question

Is there any chemical reaction if you combine povidone-iodine, salt and water together?--User777123 (talk) 21:31, 13 April 2018 (UTC)

At least in veterinary care, adding povidone-iodine to salt water is used for wound cleansing:[9] —2606:A000:4C0C:E200:0:0:0:3 (talk) 05:40, 14 April 2018 (UTC)

There might be some ion exchange between the iodide of the povidone-iodine complex and the chloride in salt, but other than that, no. 2601:646:8E01:7E0B:0:0:0:9A39 (talk) 01:17, 15 April 2018 (UTC)

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)

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)

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.

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)

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)

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)

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)

"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)

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)

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

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)

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)

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)

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

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."[10]

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[11] 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)

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)

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

There are various reports of problems with e-ink screens left in the sun here [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22]. 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 [23] [24] [25]. 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)

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)

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)

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)

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)

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

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.) --Jayron32 16:46, 16 April 2018 (UTC)

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)

Do you have those studies? It would really add to the discussion to be able to read them. --Jayron32 18:13, 16 April 2018 (UTC)

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

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)

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)

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

References

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)

• 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)

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)

• The map on page 26 of [26] shows a thickness of 5-10 meters. -Arch dude (talk) 00:59, 17 April 2018 (UTC)
• It is underlain by the Lafayette gravel. See [27]. 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)

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)

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. --Jayron32 13:42, 17 April 2018 (UTC)

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)

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)

• However, when electroplating, much thinner coatings are possible. This site [28] 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)

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

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)

• 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)

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)

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)

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)

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)

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)

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

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)

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)

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)

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)

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

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

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. --Jayron32 12:48, 18 April 2018 (UTC)

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

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)

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)

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)

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)

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

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

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)

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. --Jayron32 14:24, 18 April 2018 (UTC)

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)

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)

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. --Jayron32 16:35, 18 April 2018 (UTC)

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)

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. --Jayron32 23:55, 18 April 2018 (UTC)

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)

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)

...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)

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)

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)

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)

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)

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)

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)

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)

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)

Hence the popularity of this oldie:[29] ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:14, 19 April 2018 (UTC)

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)

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)

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)

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)

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

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

• 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)

• 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)

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)

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

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)

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)

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)

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

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)

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)

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)

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)

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)

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

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)

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

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

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)

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)

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)

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)

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)

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)

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

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)

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

• 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)

• 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)

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 scene 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)

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)

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)

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)

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

I uploaded a screenshot of the book: [30].--Doroletho (talk) 02:40, 20 April 2018 (UTC)

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)

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. --Jayron32 10:58, 20 April 2018 (UTC)

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)

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)

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

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!" --Jayron32 11:03, 20 April 2018 (UTC)

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)

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 [31]. 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)

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)

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.

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)

• 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)

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)

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. --Jayron32 13:42, 20 April 2018 (UTC)

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

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)

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. --Jayron32 16:05, 20 April 2018 (UTC)

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)

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. --Jayron32 17:55, 20 April 2018 (UTC)

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)

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)

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)

The general agreement among reliable sources seems to be that "peak lithium" is not a thing. --Jayron32 18:42, 20 April 2018 (UTC)