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January 11

Wind direction confusion

I always see sat maps showing clouds/wind moving one way and weather reports showing it moving the other way. What's going on here? [1] [2] [3] Thanks. Anna Frodesiak (talk) 01:22, 11 January 2016 (UTC)

I remember learning that an ocean current flowing from the north towards the south (for example) is called a southerly current because it is heading towards the south. Conversely, when the wind is blowing from the north towards the south (for example) it is called a northerly wind because it is coming from the north. So when you see clouds and weather systems moving south, the weather reports will talk about northerly winds. Dolphin (t) 01:29, 11 January 2016 (UTC)

Yes, actually, I agree. What the heck is a north wind? Does it come from to or head to the north?. μηδείς (talk) 01:29, 11 January 2016 (UTC)

See the first sentence in each of north wind, south wind, east wind and west wind. Dolphin (t) 01:36, 11 January 2016 (UTC)

East wind comes from the east, etc. Anna Frodesiak (talk) 01:56, 11 January 2016 (UTC)

Ah, but is that direction referenced to magnetic north or true north? The answer depends! METAR winds are true, and ATIS winds are magnetic, except Digital ATIS; and winds aloft are either true or magnetic depending on your software; and if you go to official sources, wind direction is coded... "as a number between 51 and 86 (vice 01 to 36) when the wind speed is 100 knots or greater. To derive the actual wind direction, subtract 50 from the first pair of numbers. To derive wind speed, add 100 to the second pair of numbers. For example, a forecast at 39,000 feet of "731960" shows a wind direction from 230 degrees (73-50=23) with a wind speed of 119 knots (100+19=119). Above 24,000 feet the temperature is assumed to be negative, therefore the third pair of numbers indicate a temperature of minus 60 degrees Celsius." Simple, right? Nimur (talk) 02:58, 11 January 2016 (UTC)

Well, describing a wind as "north" or "east" is comparable to giving just one significant digit of its direction. In most of the world, it would make no difference if you did mean magnetic north. --76.69.45.64 (talk) 10:08, 11 January 2016 (UTC)

Yeah - that's rather extreme pedantry. Winds don't even travel in a straight line, they follow the local pressure gradient and are affected by the coriolis force - so specifying the wind direction to the kinds of precision where you'd notice the difference between true and magnetic north is kinda silly. The exceptions to that are:

1. when the prediction is for the very immediate future - and at a single point on the ground (such as an airport) - which is why those various flight reporting services actually do care which they are talking about.
2. when you are actually near to the poles, where the difference due to those two descriptions is large.

But for general weather reporting, north, north-east, east, south-east, etc is sufficient precision. For maritime weather, they may talk about north-north-east, and east-north-east and such to get a little more precision.

Of course, if you actually are at the North pole then all winds are southerly (or, arguably, northerly) anyway - so you'd really need some kind of alternative description!

SteveBaker (talk) 13:59, 11 January 2016 (UTC)

And the weather reports are right as far as the ground-level wind direction. If it says north wind and you go to the park, the wind is coming from the north. That is always so. The odd thing is that the sat maps always show the coulds going the other way. Is this some sort of illusion where the air is squeezed and makes clouds appear so the wind is going from right to left and giving the appearance of the clouds going the other way? Anna Frodesiak (talk) 01:58, 11 January 2016 (UTC)

The wind direction often changes with height -- see e.g., wind shear and thermal wind. But if satellite imagery always shows clouds moving in the exact opposite direction from the reported winds, this suggests either a misunderstanding of how wind direction is interpreted or an error in the satellite animation loop (with the images sequenced backward in time). Shock Brigade Harvester Boris (talk) 02:05, 11 January 2016 (UTC)

It seems to b always with all weather reports and all sat loops from different sites. Anna Frodesiak (talk) 02:35, 11 January 2016 (UTC)

OK, something is messed up. If you can happen to have a current example I'll take a look. Shock Brigade Harvester Boris (talk) 02:44, 11 January 2016 (UTC)

Most winds reported for normal "retail consumers" - at popular weather websites, and television or radio news services - report only surface winds. Those can be completely different from the prevailing winds at altitudes where the clouds are. If you want to see winds aloft, you need to use a more sophisticated weather service, like the Aviation Weather service winds forecast. World Area Forecast grids are available for most of the volume of planet Earth's atmosphere, including some pretty sparsely populated areas like the northern polar regions. It takes a little skill to use those data products, because they're detailing information about a 3D volume of air movements. Sometimes, you can get a better idea of bulk air mass movement from the satellite or RADAR graphical products, or the prog charts, instead of trying to interpret wind forecasts and observations.

I also use ForeFlight, a commercial software, for supplemental weather information. It has a great user interface for looking at winds, and it provides a global wind database.

Right now, at Haikou, Hainan, China, (where our original questioner was asking about) I see northerly winds at the surface, up to about 3,000 feet AGL, and at 6000 feet AGL the winds shift toward the prevailing trend - winds out of the west - with speeds increasing all the way up to the flight levels. (Note that ForeFlight and its data are not free software: good quality, reliable weather is worth paying for!)

Down at the surface, you're probably seeing a sea breeze; it blows inland. It's reported out of the north because the weather comes from ZJHK, on the north of the island. On the other side of the island, at ZJSY, the current weather report indicates wind out of the south - in other words, the surface wind points inland all around the island!

Nimur (talk) 03:05, 11 January 2016 (UTC)

Very interesting and informative. I actually have been using http://aviationweather.gov/obs/sat/intl/ for years. Good site. So this is no illusion, right? I mean, clouds are actually moving from left to right while the reports say right to left? Anna Frodesiak (talk) 03:25, 11 January 2016 (UTC)

Correct, cloud tops over Hainan right now are well above the altitude where prevailing winds would move them "left to right" (winds out of the west, blowing clouds toward the east). Meanwhile, surface winds all around the island are in various other directions. |f you're looking at infrared or visible satellite imagery, you're usually looking at cloud tops - so the satellite loops indicate winds at higher altitudes. When you watch RADAR, it's more complex - you might be looking at cloud bases, composite reflectivity, precipitation, or some other advanced RADAR product. Nimur (talk) 03:31, 11 January 2016 (UTC)

Ouch, stupid me didn't notice the links in Anna's original post. Sorry about that. Anyway, you can find upper-level charts from various sites. Here is one example. You can click "Southeast Asia" for the map that includes Hainan, and the choose whatever pressure level you like: 850 hPa is around 1.5 km altitude; 700 hPa is around 3 km; 500 hPa is around 5.5 km; and 300/250/200 hPa are around 10/11/12 km respectively. If you look for example at the 500 hPa chart (a reasonable level to choose if you don't know what else to pick) you'll see that winds are out of the southwest, whereas the surface wind reports at Haikou that Anna linked are out of the northeast. Shock Brigade Harvester Boris (talk) 03:37, 11 January 2016 (UTC)

(Indeed, one thing to be wary of: if you're using American data sources, like National Weather Service or the links posted above - and you're looking at international forecasts - get ready to dance around a mish-mash of confusing units. You'll sometimes see feet and hectoPascals (!), meters-per-second and knots, and various "standard" barometric conventions, all mushed together in the same data report. Watch out for unit- and convention- changes, especially if the correct answers actually matter)! Nimur (talk) 03:43, 11 January 2016 (UTC)

Don't get me started on "hectopascals"... Shock Brigade Harvester Boris (talk) 03:58, 11 January 2016 (UTC)

IMO, there is no reason to use a convention, such as "East wind" meaning "coming out of the East", when one can so easily just say that. After all, for any convention there is sure to be somebody who doesn't know it or who uses a different one. StuRat (talk) 04:10, 11 January 2016 (UTC)

StuRat, nearly everything pertaining to modern, systematic meteorology has its roots in practical scientific advances that were designed for aviation applications. For example, you can read our article on the history of surface weather analysis. There is a reason we have procedure and terminology and conventions - lots of good reasons, actually.

Wind direction has a well-defined correct standard phraseology. Unlike a few of the minor details we described above - like metric and standard units, or the true- versus magnetic- direction details, deviating from this convention just means that you are reporting the wind incorrectly.

Brevity has value: to quote the AIM, "Brevity is important, and contacts should be kept as brief as possible." If it's a windy day and I'm landing an aircraft, I can call "wind check" over my radio, and get an immediate response, exactly two numbers that I can exactly interpret in an automaton-like fashion. As much as I enjoy verbose discussions about the philosophy of semantics - from the comfort of my home! - I don't want to have that conversation when I'm on short final and I can't see the wind sock.

If I want a long discussion about wind direction, ... I can read the Area Forecast Discussion, which is written in plain English. Even in these products, meteorologists still use phrases like "east wind" or "southerly wind." If you are unfamiliar with weather terminology, you can use National Weather Service's web-based, HTML web format with Glossary hyperlinks right inside in the AFD.

Non-standard phraseology contributes to accidents and incidents and generally increases workload for everybody. Standardized weather reports mean that every place we go, every local language we speak or use, every unit we use to measure, our interpretation of wind is consistent. Even the reporting-order for the weather information is standardized. Weather observers have to study standardized reporting methods and pass a certification before they can disseminate the weather report. This is why, for example, I can look at a weather brief from China and make sense of the winds.

Standard reporting also simplifies data aggregation for commercial users, weather and climate researchers, and so on.

If you're a casual consumer of weather information, none of this "convention" matters to you - but that doesn't change the value or importance of standardization for those who depend on it.

Nimur (talk) 05:56, 11 January 2016 (UTC)

Are you certain that there is no place in the world which uses the reverse convention ? StuRat (talk) 06:05, 11 January 2016 (UTC)

There is no place that correctly uses the reverse convention - at least, not while using the English language. Again, this is covered in the article, wind direction. Nimur (talk) 06:10, 11 January 2016 (UTC)

That sounds a lot like the No true Scotsman fallacy. BTW, why not concern ourselves with people who speak other languages ? StuRat (talk) 07:03, 11 January 2016 (UTC)

Science and engineering fields standardize terminology because it's extremely helpful to avoid having to constantly define terms. Similarly, as a programmer, I know that at least in programming (not always in digital signals and other EE stuff, but that's all magic anyway) a byte is eight bits, unless I know we're talking about old systems that predate the the eight-bit byte becoming universal, so I don't have to continually look up the byte size of whatever I'm working with. The no true Scotsman fallacy is when a speaker continually redefines a term that already has an accepted definition, or equivocates between multiple definitions, to a definition that is friendlier to their argument. The proverbial argument from whence the fallacy gets is name is someone saying "No Scotsman would commit a crime", being confronted with evidence of a Scotsman doing just that, and asserting the criminal isn't a true Scotsman. This is fallacious because the accepted definition of "Scotsman" is "a man from Scotland", not "a man from Scotland who has never committed a crime"; the speaker is attempting to save their false statement by redefining the word. --71.119.131.184 (talk) 10:13, 11 January 2016 (UTC)

You are using "correctly" just as NTS uses "true". That is, no matter how much evidence was presented that others use the reverse convention, or none at all, you could argue that they aren't using it correctly, just like arguing that the Scotsman isn't a true Scotsman. Also, I don't believe the 8-bit byte is as universal as you think. Some counter-examples are at Byte#Common_uses. StuRat (talk) 04:40, 12 January 2016 (UTC)

The ancient Greeks personified their winds - see Anemoi, still with the same convention we use. Mikenorton (talk) 11:48, 11 January 2016 (UTC)

Also see Zephyr. ←Baseball Bugs ^{What's up, Doc?} carrots→ 12:37, 11 January 2016 (UTC)

That's probably where our convention comes from, which in turn depends on the wind Gods blowing to produce wind. If the myths had them inhaling instead, then we would have the reverse convention. StuRat (talk) 04:48, 12 January 2016 (UTC)

I believe the logic behind specifying the direction where the wind came from (versus where it's going to) relates to the fact that the weather that is brought to you comes from a place in that relative direction. So, if you live in the northern hemisphere, a north wind is more likely to bring cold weather, a south wind, warmer. When the wind direction is from the same direction as the ocean, you'll probably get more humidity. As a practical matter, back in history when these terms first came into being - they probably didn't care much which direction the airflow was moving so much as the effect it would most likely have on the temperature and precipitation. So that convention did make a degree of sense back then, and now we're stuck with it. The convention does seem a little counter-intuitive - and we do go to some lengths to disambiguate matters in other situations. For example, we don't hear "There is a fender-bender on highway 99 and south traffic is moving slow" - we use words like "southbound" to make it clear what we mean. SteveBaker (talk) 13:59, 11 January 2016 (UTC)

Simple logic can explain it. If you're in a fixed location, you don't care where the wind is going, you care where it's coming from. The opposite would be true of ocean currents: If you're using the current to move through the water, you don't care where it's coming from, you care where it's going. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:32, 12 January 2016 (UTC)

Nimur, it is not just wind measured at the airport showing east wind while the entire province has upper-level west winds. See this. Clicking a bar near the top shows locations all over the province (Dinganxian, Wenchang, Qionghai, Wanning). From Dongfang to Sanya, all show east winds. I still don't get how this is possible. Anna Frodesiak (talk) 23:08, 11 January 2016 (UTC)

In the tropics, climatological average surface winds usually are easterly near the surface (northeasterly in the Northern Hemisphere, southeasterly in the Southern Hemisphere) while upper-level winds are westerly. This has to do with a large-scale circulation cell that dominates the equator and tropical regions. If you want more details Hadley_cell#Mechanism is not bad, or just ask. Shock Brigade Harvester Boris (talk) 01:26, 12 January 2016 (UTC)

Wow, that is bizarre. I can't make heads or tails of the article, but I will take your word for it. Next time I'm out, I will watch the clouds to see them going over in the opposite direction to the wind. Oh, and I am pretty sure that when typhoons come, the winds on the ground and clouds moving over are in the same direction. And then there's the eye, so no wind, and then it all goes backward, and then an upside down cow goes by. Many, many thanks. You've solved one of the big mysteries on my list. :) Anna Frodesiak (talk) 09:08, 12 January 2016 (UTC)

Winds at the surface and at altitude are unlikely to be in opposite directions; but their directions could easily differ by 30 degrees. When the difference is in one sense it is called "backing" and in the other sense it is called "veering". See HERE. Dolphin (t) 03:29, 13 January 2016 (UTC)

• Can I simply assume that a northerly wind means the opposite from a wind from the north? Those two terms seem to be used in opposition, but it is not always clear what is meant by northerly on forecasts, while "out of the north" is clearly unambiguous. Evene a north wind (if we look at Boreas) should be a wind blowing to the south. But I don't think newscasters are always consistent on this. μηδείς (talk) 21:15, 12 January 2016 (UTC)

No. A northerly wind is a wind from the north. You can safely assume a northerly wind is the opposite of a wind blowing towards the north. Dolphin (t) 03:32, 13 January 2016 (UTC)

For example, the term prevailing westerlies. ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:02, 13 January 2016 (UTC)

Wood's metal

Why does Wood's metal melt at a temperature so far below the melting point of all its component metals? If it's answered in one of the linked articles, I failed to find it; in particular, I wasn't able to understand Eutectic system or Fusible alloy very well. Nyttend (talk) 03:10, 11 January 2016 (UTC)

Wood's metal, for those playing along at home. The reason the melting temperature is low is an idea related to the Phase diagram#Binary phase diagrams, and the Melting point#Thermodynamics of a mixed substance. Essentially, the presence of "some substance" as an impurity in some other substance typically makes the melting point lower than if that other substance were pure(r). So an alloy of two metals is "impure" with respect to either one, and the melting point is thus expectedly lower than either one alone. Wood's metal is just one specific ratio of one specific set of chemicals that happens to have a well-defined behavior of this nature at a useful temperature. Being a "eutectic" just means it's a special ratio for the given set of chemicals that gives it additional useful melting-point properties (a narrow range of temperature for the solid/liquid transition, for example). The real questions of "why this ratio for these chemicals" and "why so much lower than the components" are much more complicated (and possibly not known in some cases beyond "because that's how they are" based on other variable that are they way they are "because that's how they are"...empirical rationalization/parameterization, etc.). DMacks (talk) 04:23, 11 January 2016 (UTC)

Nicely put. Another example is salt and water. perhaps https://en.wikipedia.org/wiki/Freezing-point_depression is applicable. Greglocock (talk) 05:19, 11 January 2016 (UTC)

The melting point of a material is determined by the forces between its molecules, and that involves a lot of complex interactions. One thing that's probably relevant is that cadmium is a group 12 element, right on the edge of the transition metals (some people even argue that they aren't true transition metals) and in the same group at mercury. These are notoriously volatile (see Metallic bonding#Strength of the bond for the details) compared to other metals, and adding cadmium to alloys often lowers their melting point because it disrupts metallic bonding. Smurrayinchester 10:58, 11 January 2016 (UTC)

See Eutectic system and freezing-point depression from the Wood's metal article. LongHairedFop (talk) 19:19, 12 January 2016 (UTC)

synthesis of tetrabutylammonium borohydride versus a PTC reaction of sodium borohydride + tetrabutylammonium bromide

I have a large amount of tetrabutylammonium bromide (although the iodide form is also available for about 130-140% the cost). While I'm waiting for another reagent to arrive, I've wondered about using and synthesising tetrabutylammonium borohydride (TBA-BH4) directly. One advantage would be that maybe I would need to use less water, or maybe not even perform a PTC reduction at all. A hypothetical procedure is as follows:

1. Dissolve TBAB in acetone
2. Dissolve sodium borohydride in acetone**
3. sodium bromide precipitates
4. Decant acetone from sodium bromide
5. Quickly evaporate (rotovap/vacuum) acetone before it has a chance to significantly react with the borohydride**
6. TBA-BH4 remains

** half-life of sodium borohydride in acetone is about 13 minutes, or 90% rxn in 40 minutes [4]  

If I'm able to evaporate the acetone quickly, I think I could get a decent yield. Of course, acetone is still moderately reactive, and I'm not sure if I want significant alkoxide counterion impurities. Is there another choice of solvent to use a Finkelstein-ish type metathesis (benzophenone?)

Partially this is due to my concerns about exposure of newly-formed imines to water even in a PTC rxn. I need the borohydride to react with the imine, but I also don't want my water to react with my imine. Is there a way to promote the lipohilicity of the borohydride ion ? Yanping Nora Soong (talk) 00:23, 11 January 2016 (UTC)

In water is used to get yields in 90% range for this sort of reaction. But the sodium bromide would dissolve in the water, so you may need to partition your TBABH4 into a more polar liquid phase. In your product dissolves nicely in dichloromethane, so perhaps this would be a better solvent. Graeme Bartlett (talk) 05:21, 11 January 2016 (UTC)

References

This chemistry is beyond my level really, but a quick search turns up chemistry forums like this one that discuss solvent considerations with this compound. While the emphasis of such forums is more recreational, the chemistry and practical limitations of independent therapeutic research are really quite similar.

I should say once again, I think you should get better answers here if you would provide details of the complete synthesis, what you're trying to make and how. Since you're not doing something illegal, why not take advantage of the ability to collaborate more openly? Wnt (talk) 15:10, 11 January 2016 (UTC)

How does this atom have such high valence?

Uranocene. How does the uranium atom have 16 different bonds sticking out of it? Also, is it wrong to call this uranium hexadecamethine or U(CH)₁₆ since the methine groups are bonded to each other? Sagittarian Milky Way (talk) 15:17, 11 January 2016 (UTC)

As I understand it (which is not very much to be honest), these are delta bonds, see this book. Mikenorton (talk) 15:27, 11 January 2016 (UTC)

Note that uranium is 5f3 6d1 7s2. Remember, s p d f hold 2, 6, 10, 14 electrons respectively, so that leaves room to add 11 f, 9 d, perhaps 6 p electrons. Of course, these will really interact as hybrid orbitals of some sort or other - what sort, I certainly can't guess. Assuming uranium contributes each of its electrons to a bond, that's six bonds, and then it can accept seven more dative bonds, plus three more if the p's are in the mix ... hmmm, that adds up to 16 bonds, coincidentally enough. But this would suppose that 26 electrons are donated into uranium orbitals, but I see only 16 electrons in the carbon pi bonds. No, maybe what goes on is that each double bond donates one "bond" to the uranium, two electrons, making it only eight bonds, a total of 16+6 = 22 electrons sitting in s2 f14 d6 maybe? Alright, now it's time to actually look it up. And [5] tells me there are six bonds from each 8-carbon ring. That means the p orbitals aren't filled ... I seem to be two electrons short even with the others. Hmmm.... Wnt (talk) 15:45, 11 January 2016 (UTC)

Wnt, you're correct that pi-bond pair is involved in bonding to the central metal atom, as usual for bonding "on the face" of pi systems such as the rings in sandwich compounds. In your "No, maybe..." analysis, you missed four electrons: the rings are formally cyclooctatetradienyl, giving ten pi electrons as a double-anion not just eight as a neutral cyclooctatetraene bond diagram contains. See Hapticity# Electrons donated by "π- ligands" vs. hapticity for some other ideas related to this aspect of counting. DMacks (talk) 17:24, 11 January 2016 (UTC)

Good point. cyclooctatetraenide has a 2- charge to make it aromatic, so there are ten electrons running around in each ring. In uranocene they aren't shown as charged, since they are covalently associated by dative bond to the uranium. But though they donate 20 electrons, they have to get their four electrons from the charge somewhere, i.e. the uranium which means it would be 20 added to 2 (in U4+) instead of 16 added to 6. I'm still counting five bonds there rather than six though, so no matter how I do the analysis in that sentence it still disagrees with the observation given in the next. Wnt (talk) 19:00, 11 January 2016 (UTC)

Ah true, didn't notice you also included U as neutral, rather than +4 based on the ionic synthesis of this compound. 2•8+6==2•10+2 indeed. DMacks (talk) 19:31, 11 January 2016 (UTC)

Well, you still should have been right that there would be five bonds' worth of pi electrons ... except that still doesn't gibe with the reported six. 8 atoms, 10 electrons, 20 "holes" to complete s+f+d, and ... six bonds per ligand. Hmmmmmmm. Now going back to basic chemistry, I know that 8 p orbitals are combined to get various degrees of overlap. psi1 = ++++++++, I think psi2 = ++++---- and psi3 = --++++--, nonbonding psi4 and psi5 = ++--++-- and +--++--+ maybe (as much bonding as antibonding contact, roughly). I suppose psi6 and psi7 might be ++-+--+- and +-++-+-- (rotated 90 degrees, four same in each), and psi8 should be +-+-+-+-. Now it's pretty clear that, despite what my source there says, the ligand is aromatic with the nonbonding orbitals full ... but if I try to push in two more electrons to fix the count, it shouldn't be aromatic anymore. So... Wnt (talk) 01:06, 12 January 2016 (UTC)

To go further in on this one: the source I cited before describes QTAIM analysis, which appears to be more theoretical than I'd supposed from context, and ELF analysis, which I take to be electron localization function analysis. The paper it cites isn't trivial to access [6] but appears to be just a crystal structure. The images ... well, the one with six bonds probably wants the 3D animation, but I've reached the point of not keeping Java on the computer, so I haven't examined it precisely. So I'm a bit out to sea here. Searching QTAIM and uranocene does turn up someone's doctoral thesis (same university as the last) which provides a lengthy introduction to some of the relevant issues. (For example, page 20 demonstrates one of the 5f orbitals en flagrante delicto with an 8-lobed 5f orbital...) [7] Wnt (talk) 13:04, 12 January 2016 (UTC)

This is really overthinking it. This is a sandwich compound. It has high hapticity. The classic case is ferrocene, which was discovered decades ago. Large metal ions are able to bond to several atoms at once, and many metallic species bind to delocalized bonds as a whole, not localised atoms. Heavy metals have many d and f orbitals, which nicely overlap with the 6 or 8 pi orbitals present in aromatic 6-8 membered rings (in this case cycloctratetraenide is aromatic, compared to its antiaromatic parent compound), just like in ferrocene, in which a much less heavy Fe(II) atom is bonded to over twelve atoms. Yanping Nora Soong (talk) 21:30, 13 January 2016 (UTC)

January 12

Intra-species violence

Which species is believed to be the most cruel to its own kind? (E.g. chimpanzees are known for genocidal behavior toward their own kind; lions sometimes kill their cubs; black widows and praying mantises eat their mates; any other examples?) 2601:646:8E01:9089:F88D:DE34:7772:8E5B (talk) 02:28, 12 January 2016 (UTC)

Adult crocodiles are known to eat other crocodiles, especially young crocs. In the case of males fighting for mates which can be quite fierce, including to the death, that's done by what are called Tournament species. Vespine (talk) 02:39, 12 January 2016 (UTC)

Thanks! So, of all these and other species, which is currently believed to have the highest level of intra-species violence? 2601:646:8E01:9089:F88D:DE34:7772:8E5B (talk) 02:41, 12 January 2016 (UTC)

I don't know how easy that's going to be to answer. There are animals that fight for territory and for mates, there are animals that perform Infanticide_(zoology), there are animals that eat their mate after courtship. I'm not sure there is any particular one that stands out more than any others. One thing to consider is that there is a very real limiting factor to being too aggressive and "killing" members of your own species, do it too much and you risk wiping your self out.. In that respect and really it should have been my 1st answer, THE species which is far and away the most cruel to its own kind is clearly homo sapiens. Vespine (talk) 04:03, 12 January 2016 (UTC)

I don't think so. Only a small portion of humans die of homicide. I'm sure that one of the categories listed above would have a higher rate of death from their own species. One other category is that some spiders, I think, eat their own mother alive. Although, if that is the "plan", not sure that it counts as cruelty, as it's functionally similar to salmon dying after spawning, to leave their bodies for the next generation to eat. Then there's birds which have two nestlings, and the strongest one kills the weaker. StuRat (talk) 04:28, 12 January 2016 (UTC)

Other examples of animals that have been observed killing their own species- rabbits, hippos, chickens, dolphins, dogs. Greglocock (talk) 05:37, 12 January 2016 (UTC)

To me, "cruel" is a human moral judgement that can't really be applied to the actions of non-humans. Your immune system is pretty "cruel" to pathogens. You're a nice big yummy salty meat bag, and you won't share even a little with them! --71.119.131.184 (talk) 05:48, 12 January 2016 (UTC)

Bingo. Animals do what they do by instinct. Pathogens and the immune system are not "cruel", they do what their DNA tells them to. With humans, aside from the occasional acts of the criminally insane, most violence against other humans is by choice. ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:08, 12 January 2016 (UTC)

• Also, I'm not sure (even if we could validly apply human morality to non-human animals, which has it's own sort of intellectual problems) we could quantify a concept like "cruelty". If we can't assign a numerical value to "cruelty" (what is zero cruelty? What is negative cruelty? What does it mean to be twice as cruel as something else; or 1.37 times as cruel, etc.), then concepts like "the most" are meaningless as well. --Jayron32 17:12, 12 January 2016 (UTC)

In the follow up, OP discusses violence. I think that concept is also nebulous, but slightly more objective than cruelty. We could in principle watch a bunch of animals and count up how often one makes another bleed, breaks a bone, blinds, etc. OP may be interested in watching elephant seals fighting, they do so rather violently and bloodily: [8]. Another animal that gets pretty rough is the hippo [9] (fair warning: both videos show graphic intra-species violence). So while we can't give any good scientific rationale for "most cruel" animal, I get the idea OP is basically looking for information/references on animals that often engage in bloody/damaging fights. Some animals, mostly insects, also get pretty violent during mating. For example, some dragonfly females take a lot of damage during copulation, as the male has all kinds of barbs and brushes that attempt to remove prior sperm and prevent future mating. Sometimes females end up with holes in their eyes or wings. Some info on that here [10], [11], [12]. A key factor influencing this violent mating is that many insects are semelparous, not itoparous, so as long as the female can manage to lay eggs, it doesn't matter much from an evolutionary perspective if she dies soon after. SemanticMantis (talk) 17:32, 12 January 2016 (UTC)

The argentine ant may be a candidate for species that kills the most individuals of its own species. In their introduced range (e.g. California), different colonies get along, because they are all closely related (a evolutionary bottleneck or founder effect). But in their native range (and some other places), each colony fights for territory with the neighbors on a nearly daily basis, with many outright deaths. Again, this works a bit different from an evolutionary perspective, mostly because the ants are eusocial, and have haplodiploid sex determination. This means that from the superorganism perspective, a bunch of workers/soldiers killing each other doesn't have the same impact as if mammalian species often fought to the death. This page [13] has some nice video and discussion of how/why some argentine ants fight a lot while others don't. SemanticMantis (talk) 17:39, 12 January 2016 (UTC)

Whether the argentine ant or another species, I think it's a fair guess that if you are trying to answer this question on the basis of the volume/proportion of members of the same species killed (and you disqualify microbes) ants are going to be your prime exemplars. I may be missing something obvious is marine life, but ants are definitely the most contentiously warlike terrestrial creatures, by and large. Of course, as SM alludes to, species differentiation with Formicidae is a very nuanced issue, in a way rather pertinent to the OP's question, as I see it. Snow ^{let's rap} 18:52, 13 January 2016 (UTC)

Wiktionary defines cruelty as "an indifference to suffering or positive pleasure in inflicting suffering.". At the very lowest levels of brain power found in animals like black widows and praying mantises - I don't think they have emotions like "indifference" or "pleasure" - and it's not particularly clear that their tiny victims can truly "suffer". I recall seeing a demonstration on TV of a house fly who's abdomen had been completely severed - and which was still eating some sugar water placed in front of it. It didn't seem like the fly was "suffering" despite this horrendous injury.

So this leaves us with two possible standards to meet:

1. Behavior which would be cruel if a human were to do it or to suffer from it.
2. Behavior which actually reflects cruelty on the behalf of the animal inflicting it.

It's easy to say that a black widow spider is unutterably cruel by eating it's mate right after intercourse - by human standards, that's quite spectacularly cruel. But neither the female nor the male spider expects anything different to happen - the female doesn't take pleasure and the male probably doesn't even understand the concept of pain. So by the standards of the spiders themselves, this wasn't "cruel" at all.

On the other hand, if a lion takes down a gazelle by gashing it with claws, forcing it to the ground and crushing it's windpipe until it suffocates...we know that the gazelle is indeed feeling pain at the time - and the lion is either indifferent or taking pleasure in the kill. So we'd be tempted to say that this was "cruel" - even from the perspective of the lion.

Yet we must be careful. Does the lion know that the gazelle is suffering? We humans would know that because we have empathy - but do we think that lions have empathy? The human brain has a specific set of cells called Mirror neurons - which fire both when we act and when we observe the same action performed by another. We literally 'feel' the pain in that gazelle. But those neurons have only been shown to exist in primates...and possibly (maybe) in some birds. If the lion doesn't have mirror neurons, then it doesn't feel what the gazelle is feeling - so how does it infer that there is suffering? If it can't infer the suffering, how can we say that it's taking pleasure in it? It's taking pleasure in having food - but it's not taking pleasure in the suffering. You could certainly argue that it's indifferent to the suffering - but not by choice - by biology.

Humans take cruelty to another level - in everything we do, we have full understanding of our ability to inflict suffering - and to empathize with the victim. We even try to take some measures to try to avoid it (eg by humanely killing animals for food). But it's hard to find any instance of a cruel-by-our-standards act in animals that we aren't also guilty of in some regard.

But even then, it's tough to measure. Many of us go through our entire lives without directly inflicting pain on anything with a sizeable brain - so are we to conclude that humanity as a whole is cruel just because some number of us are? 100% of lions take down gazelle cruelly - but probably only maybe 1% of humans have ever intentionally/cruelly killed something with a high level intelligence. So are we judging the average behavior of an entire species - or the most cruel individuals - or the least cruel?

Because of the mirror-neuron thing - I think it's entirely unreasonable to attach the term "cruelty" to non-primates. So now we're down to humans, moneys, apes, lemurs and so forth. Certainly chimps are not beyond hunting down and killing monkeys by tearing them limb from limb while still alive. Equipped with mirror neurons, they ought to be wondering how the monkey feels about that - and their thoughts on the subject ought to be pretty similar to humans. But I think it would be hard to find chimpanzees who'd be prepared to perform cruelty on the scale that (some) humans do.

SteveBaker (talk) 18:09, 12 January 2016 (UTC)

Most of your discussion seems to be about interspecific conflict, while OP is interested in conflict between individuals of the same species. SemanticMantis (talk) 20:04, 12 January 2016 (UTC)

It was a simpler statement that way - however, the same arguments surrounding what constitutes "cruelty" in non-humans, and the lack of mirror neurons in non-primates - applies to intra-species as well as inter-species violence. SteveBaker (talk) 14:50, 13 January 2016 (UTC)

Well, mirror neurons are not the only neurophysiological structures implicated in empathy, nor do we know that they are confined to primates. The general observation (going back to Darwin's The Expression of the Emotions in Man and Animal and continuing through the most contemporaneous behavioural and cognitive research) is that most mammals do possess some sense of empathy (or at least emotional/mental connection or attachment), though in many cases it may be only readily in evidence with regard to parents, offspring and/or mating partners. Still, many species have shown a propensity for expanding this circle of empathy to others, both within and even without their species, as humans do. Snow ^{let's rap} 19:04, 13 January 2016 (UTC)

Flies definitely have nocireceptors and are adverse to sensations likely to indicate damage to their bodily integrity. How much this resembles human pain is (like any issue surrounding variant perception) a deeply complicated empirical and philosophical issue. But I think it's probably safe to say they can "suffer" to some degree. Snow ^{let's rap} 18:52, 13 January 2016 (UTC)

• By the way, the mantis thing is mostly a myth. It is true that female mantises sometimes eat male mantises after sex, but that happens almost exclusively in captivity! Sexual cannibalism among mantises is rare in their natural environment, though there is one species (out of thousands) that seems to require it. Also males sometimes eat females, and that makes even less sense. See Mantis#Sexual_cannibalism, and some further info here [14] [15] [16]. SemanticMantis (talk) 20:04, 12 January 2016 (UTC)

Where sexual cannibalism does exist in species (normally where males do not survive the winter), there is a trade-off calculation. How much more likely is it that (a) the male will find another mate, and (b) how much more likely is it that if his only mate eats him, the extra nutrients will result in more healthy offspring than the chance that he might be lucky enough to mate with multiple females, and produce even more healthy offspring.

For example, the male mates with and allows the mother of her offspring to eat him. Given the bonus of protein and fat he provides, she produces 1,000 healthy eggs. Or, the male quickly escapes, and the female lays 450 not-so-healthy eggs. He repeats this, and mates with another female (if he is so lucky) who also produces 450 mediocre eggs, and escapes. He then dies from the first frost, before mating again. In that scenario, allowing oneself to be eaten is the better strategy. μηδείς (talk) 21:09, 12 January 2016 (UTC)

Aye, some of this is covered at nuptial gift, including evolutionary perspectives. While sexual cannibalism is a bit different, it's basically just a rather extreme nuptial gift in terms of evolution and maintenance of the behavior, provided that it is the female eating the male. SemanticMantis (talk) 22:42, 12 January 2016 (UTC)

Speaking of nuptial gifts, consider the recipients of this beauty. You Always Hurt the One You Love... Matt Deres (talk) 03:47, 13 January 2016 (UTC)

does degeneracy in antibonding orbitals (e.g. dichloromethane) affect reactivity?

A few years ago, an organic chemistry teaching lab professor told me one of the reasons dichloromethane is unsurprisingly unreactive is because of the symmetry (degeneracy) of the C-Cl antibonding orbitals (in addition to the fact that C-Cl bonds are hard to displace). That is, a component of dichloromethane's unreactivity (as opposed to chloroform or chloromethane) is its symmetry. I can't remember what he exactly told me, but years later in my mind, his explanation is somehow jumbled up in my mind as "the attacking nucleophile finds it hard to choose" (which antibonding orbital to attack). Of course, molecules can't really choose anything, but the overall impression I got in my mind is that degeneracy increases orbital energy (in antibonding orbitals), but decreases orbital energy in / stabilizes bonding orbitals. Years later, I'm not exactly sure what he meant, which makes it hard to find a reference for this phenomenon, so I can actually document it in dichloromethane. Is there actually any basis to my interpretation of what he said?

Unfortunately, looking at degenerate energy levels has a lot of matrix mechanics and linear algebra on eigenstates and such, but not a lot of explanations on how degeneracy affects the thermodynamics/kinetics of bond formation / bond-breaking.

I'm actually trying to improve an article here so help appreciated! Yanping Nora Soong (talk) 11:08, 12 January 2016 (UTC)

Am I right this is related to the phenomenon of avoided crossing and quantum resonance? Yanping Nora Soong (talk) 11:21, 12 January 2016 (UTC)

It's been a while since I studied things like this directly in organic chemistry, but IIRC, Bent's rule comes into play here somewhere, and researching "bent's rule" and "dichloromethane" brought up this article which discusses the situation in some detail. Maybe that will help... --Jayron32 00:21, 13 January 2016 (UTC)

Bent's rule is a succinct description of coulombic relationships in polyhalocarbons and similar molecules - just using the old orbital model. While I think it has a certain quick-and-dirty usefulness, this article in the same Web site describes what's actually going on. loupgarous (talk) 02:55, 13 January 2016 (UTC)

That article didn't really explain what was really going on, at least not to my ears. I mean, it seems to come down to an argument that p orbitals are "not real". If you want to explain that water is 104 degrees rather than 109, Bent's rule is one option; the other is the "lone pair". Is a lone pair more real than an orbital? All these things are just ways to try to approximate Schroedinger equation solutions without doing the math, because, well, you need to do serious number crunching to do the math, but nowadays I wonder how hard it would be to get us to just bite the bullet... you probably have enough processing power on a watch, right? There ought to be an app for that... :) Wnt (talk) 14:43, 14 January 2016 (UTC)

Why do dead bodies get swollen?

Why do after people die, their bodies get swollen? Is it true? and if so, Is it a physiological process? 92.249.70.153 (talk) 12:24, 12 January 2016 (UTC)

See Decomposition#Bloat. Mikenorton (talk) 12:39, 12 January 2016 (UTC)

Thank you, it's very interesting article. This step could take place in body alive or just in dead body? 92.249.70.153 (talk) 13:09, 12 January 2016 (UTC)

I'd think that the immune system and biological conditions of a living body would tend to keep such microbial populations in check while a human is alive. Otherwise, we'd all be bloated. --OuroborosCobra (talk) 14:17, 12 January 2016 (UTC)

That's basically what flatulence is (although the bacteria are eating food waste, not usually the body itself). Smurrayinchester 14:54, 12 January 2016 (UTC)

The type of bacteria which predominate in the body changes after death, with the body's chemistry. Of course, the immune system ceases to work after death, and with death, oxygen no longer is part of the human body's ecology. So aerobic organisms die off (both aerobic bacteria and human body cells) and anaerobic organisms multiply with nothing to stop them, as long as there is still tissue or fat to feed them. loupgarous (talk) 02:44, 13 January 2016 (UTC)

I believe that Herod the Great's body was decomposing before his death and Elizabeth I of England 's corpse actually exploded from bloat while lying in wait. --Dweller (talk) 15:05, 12 January 2016 (UTC)

The body of Pope Alexander VI(Rodrigo Borgia) is reputed to have decayed extremely quickly after his passing. According to our article Pope Alexander VI, "The next day the body was exhibited to the people and clergy of Rome, but was covered by an "old tapestry" ("antiquo tapete"), having become greatly disfigured by rapid decomposition. According to Raphael Volterrano: "It was a revolting scene to look at that deformed, blackened corpse, prodigiously swelled, and exhaling an infectious smell; his lips and nose were covered with brown drivel, his mouth was opened very widely, and his tongue, inflated by poison, fell out upon his chin; therefore no fanatic or devotee dared to kiss his feet or hands, as custom would have required."[54] The Venetian ambassador stated that the body was "the ugliest, most monstrous and horrible dead body that was ever seen, without any form or likeness of humanity.""

To answer the OP's question, this is a physiological process. After the human body dies, its chemistry changes. The metabolism of glucose and oxygen to power body cells ceases. The human body becomes anaerobic and a host for anaerobic bacteria, and fermentation of the body's dead tissue and fat causes gases to form within the body. As long as the dead body's skin remains intact, it swells as the gases of fermentation expand within the body. That's why dead bodies bloat. loupgarous (talk) 02:30, 13 January 2016 (UTC)

How do animal duels (clashing horns or others) and getting the female partners work?

When two male animals enter a duel, how does this work with getting a female?

Is the female around and she chooses the winner? The winner gets more territory, and the female is included? The female is around, but she doesn't choose? The losers get scared and keeps the distance towards the female owned by more powerful animals?--Bickeyboard (talk) 14:37, 12 January 2016 (UTC)

That depends on the animal. Since you talk about "clashing horns", I guess you might be thinking of deer or elk – our article Rut (mammalian reproduction) says that stags normally fight to establish dominance (if they live in herd) or territory (if they live more alone), and doesn't mention much about the females having a choice. In birds, the females watch the contests (which are competitive but not usually violent) and do chose mates - this is called a lek. Smurrayinchester 14:48, 12 January 2016 (UTC)

Lots of different ways, depending on the animal. See Bighorn_sheep#Social_structure_and_reproduction for at least three different ways males of the same species may attempt to secure a mate. SemanticMantis (talk) 17:43, 12 January 2016 (UTC)

More general information can be found by researching the following topics (both inside and outside Wikipedia): Alpha (ethology), Dominance hierarchy, and Sexual selection. --Jayron32 20:04, 12 January 2016 (UTC)

Fair warning, pay attention to the tags in the alpha article, the (at least two) deadlinks and general lack of good refs, and also note that the only recent research article cited that uses the alpha terminology is actually making the claim that alpha status is not as clear and important as previously thought in gorillas. The section on canines is (correctly) backpedaling away from using the alpha terminology for wolves. Long story short, the scientific basis for "alpha" designation in animal social groups has been continually eroding for over a decade now, and some ethologists advocate abandoning the term entirely due to the problems with it. Here's a key paper [17] that discusses (and rejects) the notion of an "alpha" wolf that asserts dominance by violence in wolf packs.

The Dominance hierarchy article is much better, and I'll just add that this theory is on strongest scientific ground when discussing the social insects. In many cases there, full physiological and mechanistic pathways leading from violence to worker sterility are understood, see here for a good overview in bumblebees: [18] SemanticMantis (talk) 20:15, 12 January 2016 (UTC)

Very good information there. I will note that Wikipedia is not the only source of information in the world, and no one will go to the OP's own house and prevent them from researching any term in sources outside of Wikipedia either. The quality of a Wikipedia article is hardly a reason to assume that no information exists in the world on a topic, and the OP is quite invited to read current research outside of Wikipedia, including the state of the concept of the "alpha" and the deprecation of the use of that term in the current academia. --Jayron32 20:21, 12 January 2016 (UTC)

Sure, and in light of that, I'll update my warning to say that all readers should be critical and wary of the "alpha" terminology, especially when searching outside WP. Scientific articles published since the 90s usually use the word with care and discussion of what it means, and why they think it should apply.

But quickly enough a web search can lead to something that seems to be about wolves but is really propaganda written by misogynists. For instance, here are some google hits for /alpha wolf/ [19] [20] that nobody should ever read, because the only information given on wolves is incorrect (and the rest is just pathetic).

Sorry for the derail, but the misuse and misapplication of the alpha concept can be intellectually dangerous, so I thought I should explain a little further. SemanticMantis (talk) 20:42, 12 January 2016 (UTC)

If really no one should ever read the articles, so why link to them? Anyway, I am aware that many people use real or imaginary social structures in the animal kingdom to justify their own "naturalness" of some human structures (as if humans should just mimic other species). Thanks for the information in any case though.Bickeyboard (talk) 22:55, 12 January 2016 (UTC)

Bickeyboard. Two solitary male muskox will do this even when there is no chance of mating. They have already left the herd, too young or old, to be able to win and get a mate. Very impressive to see. CambridgeBayWeather, Uqaqtuq (talk), Sunasuttuq 13:34, 13 January 2016 (UTC)

Thanks for asking, I think this is actually very important. I linked the articles because this is a reference desk, and I believe that we should all strive to support our assertions with references when responding to questions. In this case, I wanted to support my claim that searching for /alpha wolf/ can lead to misogynistic non-science content. Even though I don't think anyone should read the links, I supplied them because giving references is how we (should) operate. Cheers, SemanticMantis (talk) 16:10, 13 January 2016 (UTC)

January 13

Tutoring biology in a creationist curriculum

[I am revising the heading of this section from help...I accidentally agreed to become a biology lab tutor for homeschooled kids in a creationist curriculum. to Tutoring biology in a creationist curriculum, in harmony with WP:TPOC (Section headings). Please see Microcontent: How to Write Headlines, Page Titles, and Subject Lines. The new heading facilitates recognition of the topic in links and watchlists and tables of contents.

—Wavelength (talk) 16:39, 13 January 2016 (UTC)]

The short story of how I got into this predicament is that being Aspie, Asian, having complex PTSD and just being intensely conflict-adverse in general (I really dislike confrontational situations), I didn't walk out of the room or tell my new employers that I was really passionate about evolutionary biology and therefore had serious reservations about using a "Exploring Creation with Biology" textbook (screenshot of a page here). When they emailed and texted me, they didn't tell me I was supposed to teach out of a creationist textbook, just that their kids were homeschooled and they wanted me to be a microbiology lab instructor (sounded cool right? like maybe their kids were gifted). As I had already spent an hour diagnosing and fixing an issue that prevented their 40X microscope objective lens from focusing, and being several floors deep into their intimidating multifloor (probably $7000/mo rent) basement apartment underneath an Upper West Side brownstone, I was struck with indecisiveness and intense anxiety when they gave me the textbook I would be teaching from. I didn't audibly raise an objection however, though I thought my body language and lack of enthusiasm over the creationist topics was betraying my anxiety. In retrospect, I kind of feel they might not have validated my creationist credentials because they probably had unsuccessfully tried to find a creationist biology tutor in NYC. But now it's waaaay too awkward to back out.

Anyway, what are some ways to teach some really cool priming ideas about evolution without actually mentioning evolution? I still want to be able to teach really cool things like the progression of the increasing dominance of the sporophyte generation in plants as you progress from mosses to ferns to flowering plants, or conserved sectional morphology in arthropods or Hox genes, or the importance of keystone predators in ecology. In a way, I feel like I could subtly introduce the concepts behind the evolutionarily stable strategy, without explicitly teaching evolution. But I've never had such a challenge before. Yanping Nora Soong (talk) 11:57, 13 January 2016 (UTC)

This one is difficult and I don't have an answer. Could you tell us the approximate age or background of your students though? That might help others. – b_jonas 12:06, 13 January 2016 (UTC) (PS. when you say "Upper West Side", that means this is in the U.S., right?)

Yes, in New York City. They're transplants from Texas. They're two tenth grade girls (from separate families). Yanping Nora Soong (talk) 12:25, 13 January 2016 (UTC)

I would unagree and tell them so. I think you are perceiving the situation wrong - the only conflict is within you and doing a job you deeply disagree with sounds a very bad idea indeed. They would know and accept that people disagree with their views. This isn't really the right place for personal advice though, talk to a friend or something like that. Dmcq (talk) 13:01, 13 January 2016 (UTC)

I want purely scientific advice and teaching examples. I don't want any personal advice on whether I should back out or not. Yanping Nora Soong (talk) 13:06, 13 January 2016 (UTC)

If I were in your moccasins, I would teach just the factual stuff about how cells and DNA work. It's got a lot of pure science behind it and should be endlessly fascinating. If they push you to bring creationism into it, tell them that your parents said to never tell a lie, and therefore you can't teach creationism. ←Baseball Bugs ^{What's up, Doc?} carrots→ 13:13, 13 January 2016 (UTC)

I think I'd want legal advice before going along those lines. For someone who doesn't want conflict you're really digging a hole. Dmcq (talk) 13:20, 13 January 2016 (UTC)

Honestly, I think the best advice would be to back out. Trying to teach biology to creationists is not going to be satisfying either to you or to your employer. Depending on the students, it might not even be satisfying to them. I just wouldn't do it. As a tutor you have no real authority standing behind you to back you up, and you'll always be wondering if what you really want to say is going to create problems with your employer. How do you respond when your students give answers that are scientifically false but part of their doctrine of faith? It's a challenging prospect, and I wouldn't want that conflict and anxiety.

However, if you are really committed to trying this, then I would remind you that biology is a rich subject. Especially at an introductory level there are many topics such as DNA, proteins, cell structures, anatomy, biological diversity, etc. that can be discussed without bringing up evolution. Now many of these concepts lose something if you don't invoke evolution to explain how they are tied together, but that is likely one of many compromises you would have to make to go forward. Discussing things like biological diversity without bringing up evolution is perhaps a bit like stamp collecting, but there is still a wealth of biological forms and ecological approaches that are interesting and educational. Assuming you have been hired with the intention of teaching for at least several months, then I would encourage you to spend at least the first month with topics that keep evolution as far away from the discussion as possible. Tenth graders aren't stupid and even if homeschooled are likely to have some awareness of evolution. If they think your teaching has an underlying evolutionary agenda, then they are likely to bring it up, which has a good chance of ending badly. If you are going to eventually reach for "priming ideas about evolution" then you should probably first try to build a rapport with the students if they are ever going to take you seriously. Go slow, and look first for areas where you can teach effectively without having to color or avoid the truth. Dragons flight (talk) 13:28, 13 January 2016 (UTC)

Also, you might want to consider whether it would be good to talk to the parents about their beliefs on evolution and how they would like you to deal with the subject. Discussing it might not be easy, but knowing what they are looking for might reduce problems later. Dragons flight (talk) 14:36, 13 January 2016 (UTC)

I wonder how much ground there is for rapprochement. That textbook page is truly horrid, of course - but creationism, broadly defined, is not actually contradicted by science. Consider:

• The anthropic principle states that we live in one world out of a vast number, perhaps one universe out of a vast multiverse, because that world contains sentient life.

• Sentient life, as opposed to mere machines, is defined by the presence of qualia, a fundamentally paranormal phenomenon which is in no way understood by science.

• In fact, in the Copenhagen interpretation of quantum physics, the presence of the conscious observer collapses a random fog of probability into one particular option. In other words -- the world does not even exist in a particular form, save that it is viewed by a sentient observer.

• If, therefore, we were to define a phenomenon that causes qualia to come into existence, then that phenomenon would, according to well established physical principles, impose requirements about the world we live in, and actually create that world, both its past and its future, out of a uniform fog of undifferentiated possibilities.

This is not really that far from a creationist position. However, we would need to broach with the creationists a certain degree of Last Thursdayism, which is to say, they should not have to believe a turgid text that says that all the layers of rock were laid down in some global cataclysm when that's not what the data shows us. We have to postulate a God powerful enough to create the past. Wnt (talk) 13:37, 13 January 2016 (UTC)

What you are describing, Wnt, is related to Creation science and Quantum mysticism. And it is conflicting with basic principles like Occam's razor, avoid Confirmation bias, or 'the universe does not care about what you think.' (don't know the real name of this principle at the moment, I will update if it comes to my mind). Russell's Teapot is also of help here. Denidi (talk) 14:26, 13 January 2016 (UTC)

@Wnt: No - several of your points are entirely incorrect.

• The anthropic principle...you are discussing the strong anthropic principle - which is not widely accepted. It says that the universe is the way it is in order that we will exist to observe it. That's essentially creationism. The principle that's more widely accepted in science is the weak anthropic principle which says that this is a matter of selection bias. Of all possible universes, only those with properties that are conducive to producing intelligent life will be observed. Nothing mystical there.

• The presence of qualia...Indeed, science has (as yet) failed to understand this phenomenon - but it's widely agreed amongst physicists and biologists that sentient beings are indeed just machines - and that we'll eventually (perhaps very soon) be able to create machines that produce this phenomenon...or perhaps deconstruct the phenomenon to the point where we realize that it's just an illusion created by the machine itself. Qualia#Critics_of_qualia makes interesting reading. Whatever the outcome of investigations, it's not reasonable to draw the conclusion that humans are in some way not machines - or are in some deep fashion working outside of the laws of physics - just because there is something here that we don't yet understand. There are many things that science doesn't yet understand - and automatically dumping those things into the realms of mysticism and religion is medieval thinking at it's very worst.

• The Copenhagen interpretation of quantum physics...is rapidly falling in popularity (recent studies show that fewer than 50% of quantum physics experts believe it to be correct - down from 80% ten years ago). In any case an "observation" does not imply the presence of a sentient/conscious observer - and I doubt that this is the interpretation of the term for any of the remaining proponents of Cophenhagen. Measurement in quantum mechanics states "there remains less than universal agreement among physicists on some aspects of the question of what constitutes a measurement". In no way can you interpret this as proof that sentience/consciousness is a requirement for the existence of the universe...and you should no longer claim that more than a tiny percentage of working scientists endorse this view...they don't.

• If, therefore, we were to define a phenomenon that causes qualia to come into existence, then that phenomenon would, according to well established physical principles, impose requirements about the world we live in, and actually create that world, both its past and its future, out of a uniform fog of undifferentiated possibilities. -- This is not a valid conclusion from your previous comments...which (as I've pointed out) are incorrect in the first place. Cunningly hiding a link to God behind the word phenomenon is sneaky and unhelpful here. What you're spouting here is creationism, pure and simple - so let's not try to clothe it in the wrappings of science - it's not.

The truth is that science cannot ever disprove the existence of a god or gods - it's an unfalsifiable claim. But scientists are overwhelmingly certain that we are sufficiently close to an explanation of everything that adding a 'creator' into the mix doesn't improve the description...indeed it just pushes back the question to "what created the creator". Saying that the creator "always existed" - or "just popped into existence from the void" - is no better than saying that the singularity that started the big bang always existed. So if that kind of zero-evidence claim is acceptable to you, then you have a physically plausible description of everything that doesn't lie outside of the realms of science. Occam's razor says that if we can demonstrate how the universe came to exist using only the laws of physics - then we should ignore the 'god hypothesis' because it introduces unnecessary concepts. Aside from the big bang, the only scrap of science that's really missing in the description of how we came to be is the abiogenesis event - but the issue there isn't that we can't find a physical means by which that initial spark of life came about - it's that we can't (yet) decide which of a half dozen strong candidates is the correct one.

Claiming that you can teach serious biology 'around' the existence of a creator is just wrong.

To our OP, in your position, I'd just ignore the stupid text book - fall back on your honor as a teacher. Teach straight up biology and let the idiots fire you if/when they find out. Being a biology teacher who was fired for not teaching creationism is a badge of honor - something that you should be proud to put on your resume.

SteveBaker (talk) 14:41, 13 January 2016 (UTC)

@SteveBaker: This is a decent try, but I don't think it's as thorough a rebuttal as you think. Now I'll admit that I'm a bit hazy on the difference between strong and weak anthropic principles - I don't see a difference between saying the existence of consciousness implies we are in a universe that permits it, and saying it implies we live on a planet that permits it, at a temperature range that permits it, etc. The second point you're outright wrong on - you can't tell me science has no model for qualia, then say you could take a vote and that is how things are! The third, well, to begin with, one "interpretation" of quantum mechanics isn't supposed to be different from any other, but we recognize our observation changes things in all of them. If you like many-worlds, well, then you have to explain why the qualia of your experience matters in one particular world, and without those qualia to define the measurement, you have all the infinite worlds piled on top of each other with no way to say which is true and which is false for you; there is no you. Now in the last part, I may have been taking liberties. Clearly such an argument cannot say a particular idea of God is or isn't meaningful. I'm putting the telescope the other way round and saying, if qualia are so important, then we can define the mechanism by which qualia are created as something important. Now that "something", being directly responsible for defining what all thinking feeling beings in the cosmos are, has properties that might be guessed at, rightly or wrongly - specifically, one may suspect it too is thinking and feeling. And if a force is at once universal, defines consciousness, and with it what worlds it is possible for consciousness to perceive, and yet personal, thinking and feeling, that closely albeit vaguely matches a religious conception of God. Wnt (talk) 21:39, 13 January 2016 (UTC)

Maybe Wnt should be the teacher there.Denidi (talk) 15:33, 13 January 2016 (UTC)

@Wnt: You question my rebuttal while admitting to not knowing what you're talking about? Good one!

• Weak versus strong anthropic principle. What you originally stated was the "strong" form - that we exist because the universe exists specifically in order to produce intelligent beings - that this is somehow its "function"...this is not well supported by science - it's basically creationism-lite. The "weak" form is so simple that it more or less cannot be false. It says that if the universe/solar-system/planet-earth was not more or less exactly like it is, then we would not be here to notice and write about it. In many-worlds hypotheses, we only exist in universes that have the right properties - ergo, the only one we can study is the one that has those properties...but even questions like "what are the odds that we'd happen to arise on a planet with just the right amount of oxygen in the atmosphere?" may be answered by the weak anthropic principle...on planets that don't have that property, there are no humans to notice that they don't have that property. You can't look at the world and say "It's perfect for us, so it must have been created just for us!" - that's not supportable by the laws of physics. The truth is that you should look at us and say "We are a perfect fit for the world we exist on - evolution works!"

• On qualia - you said: "you can't tell me science has no model for qualia, then say you could take a vote and that is how things are!" - I didn't say that, I merely pointed out that absence of evidence isn't evidence of absence. Just because we don't yet understand qualia as a physics-based phenomenon doesn't allow you to jump to the conclusion that it's not a physics-based phenomenon and therefore some supernatural answer is required.

• On quantum effects - let us consider the Schrodinger Cat thing. We put the cat in the box, quantum superposition happens and the cat is neither alive nor dead. Copenhagen says that when the cat is "observed" (this being an ill-defined term) it becomes definitely one or the other. But in other interpretations, when the physicist opens the box, he too becomes a quantum superposition between a physicist who is happy that his cat is OK and a physicist who wonders how he's going to break the news to his wife. When he phones her to tell her the outcome, she too becomes a quantum superposition of happy-wife and wife-who-wishes-her-husband-would-stop-experimenting-on-their-pets! Each superposition of the physicist has it's own qualia - each one thinks and believes accordingly. From the perspective one of the two superposed physicists, his opening of the box "resolved" the cat into the dead state - and as far as he can tell, it was his "observation" that caused that. There is no way for him, or anyone else to tell the difference between a universe where Copenhagen is true and one where superpositions spread. Radio waves from the physicist's cellphopne ripple outwards as quantum superposition spreads into the entire universe. Other ripples from other quantum events result in an impossibly complex tangle of superpositions of superpositions which are never truly 'resolved' or 'collapsed', except from the perspective of things that are themselves superpositioned. The beauty of the interpretation I gave (which bears close resemblance to many-worlds with superpositions standing in for parallel universes) is that there is no special "act of observation by an intelligent being" to wrestle with. So here you do have two different "interpretations" of quantum theory which are essentially indistinguishable - one of which leads you to the mysticism of intelligence being magical - the other of which works perfectly well without that, using only the laws of physics as we know them to be. Occam's razor tells you what to do about that!

• ...and then in your conclusion, you (again) spiral off into the realms of the supernatural - based only on the presumption that these "qualia" are supernatural in nature. If sometime soon we were to produce computer programs that exhibited this phenomenon - your claims would fall to the ground. Everything you're arguing depends on your interpretation of an unknown.

Given what we know about physics, human beings are made of mundane atoms, whose properties are simple enough - other animals exhibit similar behaviors grading from the clearly not intelligent (bacteria) to the clearly intelligent, qualia-bearing higher mammals (great apes, cetaceans, elephants, etc) - which strongly suggests that evolution is the cause of the complexities of our brains - and that evolution caused the "qualia" phenomenon by producing sufficient computational complexity. Given that clearly laid out path, it's unreasonable to start off by presuming that qualia are something beyond the realms of the laws of physics. Far more likely is that it's an emergent behavior of any sufficiently complex neural network.

What you're saying is an unsubstantiated act of faith (faith that qualia will not be 'decoded' by science) - which is religion of one kind or another. Science has good reason to suggest that qualia are not in some way supernatural. We've demonstrated all sorts of emergent behavior in complex evolving systems - why not this one? What you're suggesting to our OP is that your approach as a compromise between science and creationism is in fact, it's just creationism sneaking in through the back door.

You're using a classic "God of the gaps" strategy of trying to place a creator into any place in the realms of physics that are not yet fully resolved. As science advances and more and more of these gaps are closed - your system of religion shrinks further into the distance. No longer did god create all of the animals in a week - we've closed that gap with evolution - and firmly disproved it with dinosaur fossils. No longer did he make the heavens and the earth - we've figured out planetary formation - we know the history of the earth, the stars and the galaxies - and seeing the cosmic background radiation proves that too. We know what happened with great confidence going back to within a few microseconds of the big bang. God now gets to push the big green "GO" button on the big bang, sprinkle in some dark matter, maybe do a one-off magic trick with abiogenesis and maybe fiddle around with qualia...that's it. Science has been closing those gaps for 200 years now. You really think those other ones won't get closed in the next 200?

SteveBaker (talk) 15:10, 14 January 2016 (UTC)

I think you're putting too many constraints on what creationism should refer to - constraints that some creationists, such as the ones that wrote that awful textbook, may accept, but which nonetheless do not disprove the existence of God or the purpose of the cosmos. To suppose that God gets to "press the big green GO button" is to suppose that God as an author writes in a strictly chronological order, but I don't think that assumption is sustainable. To illustrate, I would expect a Creator to be able to craft a perfect sunrise, then sketch in a landscape beneath it, make that landscape an infinite plane under a firmament full of little holes, revise to a round disc, change to a ball in space surrounded by revolving crystal spheres, etc., iteration after iteration, gradually sketching in layers of rock, adding new minerals, putting fossils in those layers and writing a story of how they arose from living beings, and so on. And so the things in your last paragraph don't really hold.

That's not to say that creationists are justified in saying that evolution was fake, that the deep past didn't really happen - only that there is no actual progress in pushing back things to the big green "GO" button; you're just begging the question. You haven't explained why reality is real, more so than some anti de Sitter space of physicists' contemplations --- but if reality is real, then its reality derives solely from qualia, which is to say, from our perception, as sentient beings, that we live in it. (To me this, incidentally, seems very close to the sense of purpose you say is demanded by the strong anthropic principle) And the problem with qualia is more fundamental than most. Do you really think you're going to write up some equation on a blackboard and say whoah, wait a minute, this equation thinks! This equation feels when I put the wrong number in the denominator? Do you think you're going to have a memory chip and you change a few bits, put a logical rotate left here and a NOP there, and all of a sudden the computer feels? And with many-worlds, well ... Occam's razor should not take kindly to them. You realize that your formulation of that position means quantum immortality is a thing?

I can't write an epistle here, by my opinion is that qualia shares the same root cause as other paranormal phenomena, which is to say, precognition - which is a very difficult and dangerous phenomenon to study, but has the property of creating macroscopic causality violations that represent internal boundary conditions for the universe; I would suggest it is there, not at some past mathematical singularity, that any "GO" buttons actually reside. Wnt (talk) 16:52, 14 January 2016 (UTC)

@Wnt: We're getting very, very far off-topic here - but let me just say that I actually do expect to either find that some piece of software will ultimately have "self-awareness" (perhaps some already do, but are just too primitive to express the fact) - I doubt that a human will write that software with "an equation" or "a logical rotate left here". But I wouldn't be at all surprised for a deep learning system along the lines of IBM's Watson or Google's :Deep Mind were to start to behave more like a simple animal - and through machine-evolution and training might one day be able to express this odd feeling that humans have of "being here". The concept of the Internet becoming self-aware is not so far-fetched to me.

Mostly it's a problem of complexity. The human brain has somewhere between 100 trillion and a quadrillion synaptic connections - and the most complex computing systems can't begin to perform at remotely that level of processing. So 'emergent' behavior like that won't happen for a long time to come...but, yes, I'm quite sure we'll get there because humans are made of atoms - and we can make stuff with atoms.

Your concept that "I would expect a Creator to be able to craft a perfect sunrise, then sketch in a landscape beneath it..." etc is very beautiful and poetic - but God evidently feels constrained to only produce things that obey the laws of physics - why this is, I'm sure you wouldn't want to say - but the fact is that once we've figured out one of these rules - it's followed to perfection across all of space and time. So the perfect night sky has to include a teensy tiny bit of cosmic background radiation in it that just perfectly mimics what the math would produce if there had been a big bang...and that's what happens in reality. This kind of thing means that God can't produce the perfect sunset without messing up the refractive indices of oxygen and nitrogen, screwing with the physics of Rayleigh scattering and Mie scattering, the spectrum of light produced from hydrogen fusing into helium and so forth. All of which mathematically predict the colors you'll see to perfection in every single sunset we've ever measured.

So to engineer that sunset to look "perfect", your hypothetical god would have had to set up the fundamental laws and constants of the universe to make that happen...and having done so, would then be self-constrained to produce a particularly horrible sunset at some other place and time (which, indeed, he routinely does). Far from being able to incrementally tinker - he has a set of (arguably, self-imposed) rules that he has to stick to throughout space and time in order to keep people from being able to unambiguously detect his existence. Which means (getting back to my point) that in effect, pushing the big green "GO" button (admittedly with a set of physical laws of his choosing) is the only thing he can have done. I'll admit that he may have set those equations up in such a manner as to produce a very specific sunset at a very specific time and place in the entire universe - but he most certainly did not give himself the ability to produce perfect sunsets on demand at any time or place...for that, he'd have needed more flexibility in the physics he'd have had to design - and we can measure the degree of that flexibility...it's zero.

SteveBaker (talk) 19:04, 14 January 2016 (UTC)

We are pretty far afield, but the flexibility of physics certainly isn't zero. So far as I know, physics is nondeterministic at least once the state-vector is collapsed by a conscious observer, but let's not go round that one again :). Weather is a chaotic system, so no one can predict where lovely sunrises will and won't be. Ordinarily I see nondeterminism presented as some kind of proof the universe is not merely random but without purpose, but I would think it ought to just as readily provide an opportunity for events to be part of a master plan without having to be hard-coded into the laws of physics. It is of course not uncommon for a human author to balance laws of magic or sci-fi with the events he's trying to write about, changing the former when necessary to allow the plot he wants, and the latter to keep in-world consistency. Wnt (talk) 00:31, 15 January 2016 (UTC)

Here's a question for you to consider: is there an "evolution-shaped hole" in the text book? Meaning, there is tons of cool microbiology to learn at grade 10 level without covering much evolution, but if you know your stuff, you should be able to see the bits where the lack of evolution makes things more confusing. My advice is to wallow in those holes, and if your students are bright and inquisitive, they may ask. And if you feel you can't answer without risking your job, then at least you've sown the proper seeds.

An additional tack: ecology is your friend here. Even Christian Fundamentalists who hate the idea of evolution usually think ecology is ok. But Nothing_in_Biology_Makes_Sense_Except_in_the_Light_of_Evolution, and this is doubly true for ecology. So sure, mention keystone predators. Mention ecosystem engineers. Mention the paradox of the plankton. Mention the Carbon cycle, and you can even sneak in a little primer on climate change! Mention all the wacky symbioses that occur in in microbes, tell them about how bacteriophages can lurk in the Lysogenic_cycle, maybe even symbiogenesis. All these things will lead back to evolution, even if you feel as though you can't mention it directly without risking your job. Also of course encourage your students to seek other sources of information! But really, at a 10th grade level, it may be largely too late. The children may have already been indoctrinated that evolution is a liberal lie promoted by immoral agents. Let me know if you'd like more specifics on the ecology angle. SemanticMantis (talk) 15:08, 13 January 2016 (UTC)

I have the impression that creationists, for whatever reason, are also climate change denialists. That makes already two points of conflict. And let's not talk about anything related to sexuality or genetics.

My pedagogical advise: do not teach, but lead the students to their conclusion, let them explore and connect logically what they find. It is difficult to dance around the whole evidence pointing towards evolution and still talk about biology.

--Denidi (talk) 15:31, 13 January 2016 (UTC)

Finding another job as a home-school biology tutor who does not want to teach creationism might be a challenge anyway. People with enough money to hire a tutor tend to home-school when they want to avoid their kids learning the standard biology curriculum. What bothers me is that these kids should have to achieve the same level of learning as kids in mainstream schools - which ought to mean that they have to pass the standardized tests in Biology - which in turn ought to require a working knowledge of evolution. I wonder how they can duck out of that? Meanwhile, I'd just teach biology the right way and see what happens. SteveBaker (talk) 16:11, 13 January 2016 (UTC)

You also may get some ideas from E.O. Wilson's book Consilience_(book) (available for skimming here [21], and our general article on the topic is at consilience). Wilson, one of the greatest living biologists, writes in a way that attempts to not turn off creationists too much. Even though he knows their perspectives are unscientific, he wants to teach them and get them on board with things like conservation and climate change. So it might be a useful guide for getting evolutionary ideas out there in a way that won't cause certain creationists to completely tune out. Also, I see now that the book is specifically attempting to cast evolutionary theory as uncertain and incredible. They attempt to do this through encouraging critical and skeptical analysis. If you and the students are up to the task, this approach will surely backfire. E.g. uniformitarianism goes a long way in addressing the question you linked, and the fossil record is not the sole reason we scientists believe evolution to be a true description anyway. Also I'm fairly certain the book is not using the term scientific theory in good faith, and it would be good to make sure your students are aware of the standard definition of the concept. SemanticMantis (talk) 16:22, 13 January 2016 (UTC)

Is that a legally uploaded book? I am afraid that mentioning it's only "available for skimming" would still be a copyright breach. --Scicurious (talk) 17:53, 13 January 2016 (UTC)

It's one page out of hundreds of pages. I photographed it under the guise of facilitating lesson preparation (there was only one copy). Yanping Nora Soong (talk) 21:58, 13 January 2016 (UTC)

I meant the book linked to by SemanticMantis. There is more about this on my talk page.Scicurious (talk) 22:58, 13 January 2016 (UTC)

Another question to OP. Are you sure that the parents don't want you to teach evolution to the students? Is it possible that they simply do not know what's in that particular textbook, or even if they do know, they don't insist on teaching only their beliefs? – b_jonas 16:43, 13 January 2016 (UTC)

They explicitly brought this up at the end. By then it was hours into our meeting, I had already helped them order lab supplies, and it was too awkward for me to express my internal conflict at that point. I am not against conflicts with students, I have definitely dealt with motivating students before -- I'm just averse to conflict with those who have power and influence over my economic situation. Yanping Nora Soong (talk) 21:58, 13 January 2016 (UTC)

The original poster resides in New York City. Requirements to legally teach in New York State are among the strictest and most stringently-enforced in the nation; and the standards for the curriculum are very clearly specified, the certification requirements are very high; and if the Government doesn't get you, the teacher unions will - because New York State is not a right to work state, teachers must join the union. Tread cautiously with the application of your job-title, lest one evening you find yourself in some darkened borough back-alley, surrounded by administrators and school-teachers who have some questions for you about test-battery.

So let's be clear: the OP is a "supplemental resource" who is assisting the students by tutoring them while they are at home; he or she is not a teacher. Even if all of us find the students' education to be unsatisfactory, at some point those students will have to pass the Regents tests, a battery that checks whether the students have satisfactorily learned the curriculum mandated by their state. In other words, our opinions are irrelevant: there is a well-ordered standardized system to verify that the students have received the education as required in New York.

Regarding the students, and their curriculum: I was a past participant in that school system - and I passed the Board of Regents' examination in biology, too - before they renamed the Biology test to something more politically-correct! - New York is not some podunk town where you can freewheel your own curriculum and slip under the radar unnoticed. If you can't pass muster on the standards, The State will simply fail to grant a high-school diploma. If the parents are okay with that, then deviate from the curriculum as much as you see fit! As you are not actually the students' teacher, you really have no obligation or accountability or conflict of interest.

In seriousness, our OP is probably not suited to this job. Teachers train for years, inside and outside of classrooms; among their many honed skills are techniques for dealing with parents when there are disagreements about the methods and contents in the child's education. This policy-stuff is harder than the actual subject-matter; and that's why there is an entire profession dedicated to it. Even if you don't go to college for a degree in teaching, there are still years of mandatory preparation.

If you just show up one day and start teaching kids, you're an unqualified, unlicensed teacher and you are part of the education problem, no matter how noble your intentions are.

Nimur (talk) 17:10, 13 January 2016 (UTC)

New York does not issue high school diplomas to home schooled students, period. Home schooled students are encouraged (but not required) to take Regents exams, and the state will provide official scores to the student and to prospective colleges, but home schooled students are categorically ineligible for a Regents diploma regardless of their actual scores. The only high school equivalency New York presently issues for home schooled students in the GED, obtained in the usual way. To remain in good standing, home students are required to submit an "annual assessment" each year usually including a standardized test, though they may choose among several approved tests. Dragons flight (talk) 17:51, 13 January 2016 (UTC)

I'm a private tutor hired through a private tutor service. Where did I say I was a teacher? Also, Teach for America (I have several well-qualified friends who are in the program) takes the best and the brightest college graduates, assigns them to a city, rural area or a school, puts them in an intensive crash course for eight weeks, and then they start teaching. The idea behind TFA is that critically-thinking physics, chemistry and biology majors who focus on their subject material for 4 years and then teaching methods for 8 weeks (and then acquire certification on the job) usually make for better and more competent teachers than education majors who study education for four years and end up choosing to specialize in science in their fifth year. In any case, I am not in Teach for America, (they screen candidates by student leadership experience, and I wasn't a major student leader at UVa, unlike some of my really gifted friends) and I think I passed the two-year leniency period post-graduation to apply when January 1 rolled around. I am not a teacher. I am a private tutor who was excited about accepting more responsibility. That's how I got into this whole predicament.

I have tutored tons of kids before from this tutor-student matchmaking service they hired me from, college students and high school kids alike. I also was a peer teacher who helped a TA run her section of an evolutionary biology (!) teaching lab course. Basically, I have peer-taught evolutionary biology lab sections before, I'm just not used to teaching it without the evolution. And as someone said above....I suddenly realize I'm not really into biological stamp collecting. The sponges, hydra and the mosses were cool because you could start to see organizational forces and the evolution of multicellular communities at work. I am not sure how to impart all that without explicitly teaching evolution. But I feel like I might be able to teach the idea of self-reinforcing communities under the radar. Yanping Nora Soong (talk) 21:49, 13 January 2016 (UTC)

What kind of restrictions, if any, are in your contract? ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:46, 13 January 2016 (UTC)

I don't have a contract per se. I'm just not into getting bad reviews or tutor ratings through my tutor-student matchmaking service. Yanping Nora Soong (talk) 21:51, 13 January 2016 (UTC)

OK, more to the point: Are you doing this for free? If not, who's paying you? ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:54, 13 January 2016 (UTC)

I'm being paid through my agency at a rate of $40/hour. Yanping Nora Soong (talk) 22:00, 13 January 2016 (UTC)

Does the agency require that you teach from the book the parents specify? ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:13, 13 January 2016 (UTC)

OP, the idea is to stick to the science as much as possible. "Evolution" is a triggering word with creationists - it works on their brains just like a finger stuck deeply down your throat. However, you can deal in the ideas which caused Darwin to develop the concept of evolution without mentioning evolution, Charles Darwin, or anything else apt to cause creationists to shut down thinking. Natural selection (as long as you don't call it that) offers a wide and fertile field for raising students' consciousness about the processes which actually drive evolution. I'd actually stick with that, it's the very least speculative proof of evolution. I'd avoid things like the Miller-Urey experiment or any work inspired by it like the plague, purely because that, also, is a potent trigger for creationist ranting (not to mention somewhat controversial on scientific grounds because of the lack of agreement on the nature of the primordial environment). If you just absolutely want to be safe, stick with natural selection. loupgarous (talk) 21:10, 14 January 2016 (UTC)

Commercialisation of healthcare

Is healthcare like many non business sectors becoming increasingly commercialised? Are doctors and healthcare staff spending time following guidelines and policies or trying to change them, managing budgets efficiently and doing paperwork more than treating patients? 2A02:C7D:B91D:CC00:49C0:230D:5EC7:DCC1 (talk) 19:40, 13 January 2016 (UTC)

Undoubtedly it's happening in some places, and in some it has already happened to a greater or lesser degree. I think this kind of question asks for too much conjecture and opinion. Just google "commercialization of health care," many people have written loads of articles and opinion pieces about the subject, that's where I would start. Vespine (talk) 21:40, 13 January 2016 (UTC)

This is not exactly a recent development. It's been this way for decades, though it may be getting worse. The current Reader's Digest has an article called "50 secrets your hospital won't tell you", which you may find enlightening. ←Baseball Bugs ^{What's up, Doc?} carrots→ 21:40, 13 January 2016 (UTC)

Why do some viruses have silly names?

Like jerseylikevirus (something to do with New Jersey?), barnyardlikevirus (discovered in a barnyard?) and bignuzlikevirus? (Big nuts-like virus?) (Those are at List of genera of viruses if you don't believe they're real). There's no jerseyvirus, newjerseyvirus, novojerseyvirus [Latin name for Jersey]virus or anything on the list that could be a Jersey virus so why is it named jerseylikevirus? Why do they use English words instead of Latin? Sagittarian Milky Way (talk) 20:08, 13 January 2016 (UTC)

Using PubMed, I quickly find [22] but it lets me down on the other two. Nonetheless, Expasy indexes [23], [24] and [25]. So these are real isolates. There is very, very little published about them - the latter two are random phages on mycobacteria. But such phages are potentially lifesaving interventions, so it is indeed useful to index them. According to the sequence record [26] there is a course involved in finding the last two of these, so the names may be unusually whimsical for that reason; I'm not sure. Wnt (talk) 21:21, 13 January 2016 (UTC)

As for the name "bignuzlikevirus", this might possibly refer to Big Nuz, which according to the linked page is a "is a well-known and highly celebrated Durban-based kwaito group". Perhaps the virologist who named it was a fan of theirs; "like" might refer in some way to its shape. But all of this is only a guess. The musical group's page says that "Nuz" is a reference to license plates, but presumably it is also a pun on news. --76.69.45.64 (talk) 22:21, 13 January 2016 (UTC)

Hmmm, looking at it again, the merry-go-round always goes past the sequence publication. I found an NCBI taxonomy entry [27], the application that made these names [28], both reference a virology paper from 2012 [29] but all trace back to the original sequence [30]. Wnt (talk) 23:53, 13 January 2016 (UTC)

The general practice is to name a newly-discovered virus after the place in which it was first identified. That can make for odd viral names, and even counter-intuitive ones.

Richard Preston used Humpty Doo virus as a plot device in his novel The Cobra Event. Preston had one of the novel's characters think that a piece of equipment used to identify DNA sequences in a sample had broken when it reported one sequence as being from Humpty Doo virus, but Humpty Doo is an actual town in Australia for which Humpty Doo virus, a rhabdovirus which infects kangaroos but not humans, was named.

Marburgvirus originates from the vicinity of Lake Victoria in Africa, but is named after the city of Marburg, Hesse, Germany, where it was first identified when infected monkeys captured near Lake Victoria and shipped to the Behring Works in Marburg transmitted the virus to humans, causing an outbreak of human marburgvirus infection. loupgarous (talk) 22:43, 14 January 2016 (UTC)

Fructoselysine article - need categories

Hello - just seen a new article on the new pages feed for fructoselysine. It was very basic and I've improved it by adding citations, but I'm not sure of the right categories. Can someone add some? Some information on how it's produced would be nice, too. Would look this up myself but I need to sign off now. Blythwood (talk) 22:34, 13 January 2016 (UTC)

Hmmm, there are a lot of scientific references to that name, but my expectation was that it would be fructosyllysine. Looking up the latter name, I find [31]; not that but a charged form [32] list fructoselysine as a synonym. Ought to figure out who is "right"... Wnt (talk) 23:59, 13 January 2016 (UTC)

January 14

Electric motors and hybrid vehicles

Hybrid in the sense of a flying car or a car boat, something along those lines. If you were to make these things using electric motors, do you need separate electric motors to drive the wheels and the propeller/jets? Or could you in theory use a single electric motor to provide power to both the wheels and the propellers/jets? ScienceApe (talk) 04:32, 14 January 2016 (UTC)

Yes you could use just one motor and a complex transmission, or you could devote one motor to each wheel/prop. If your design never uses both forms of propulsion at once then you may come in cheaper/lighter with a single motor solution. Greglocock (talk) 05:13, 14 January 2016 (UTC)

"propeller/jets" - probably not jets. The hard part for small planes is payload weight is traded for fuel. --DHeyward (talk) 05:35, 14 January 2016 (UTC)

I took "jets" to mean the boat kind, as in a Jet Ski not the airplane kind. StuRat (talk) 05:45, 14 January 2016 (UTC)

Terrafugia has been pitching their "Transition" aircraft, which uses one engine: "Running on premium unleaded automotive gasoline, the same engine powers the propeller in flight or the rear wheels on the ground." Their proposed TF-X will have multiple electric engines. They just need somebody to design it, build it, program it, test it, operate it, fund it, ...

Nimur (talk) 17:33, 14 January 2016 (UTC)

For the flying car, weight is critical, so you really don't want an electric motor to start with, because they, along with the required batteries, have a lower power-to-weight ratio than gasoline, jet fuel, etc. Also, a car can't be designed with the same lightweight components you use in a plane, or it would be too fragile for the road. So, an electric-powered flying car is quite impractical (it might be possible, but that's not the same as practical).

For the amphibious vehicle, electric power would be a bit more practical, as power-to-weight ratio is less of a concern. There are basically two types I am aware of, hovercraft and ducks. The power-to-weight ratio would be less of a concern in the second type. StuRat (talk) 05:42, 14 January 2016 (UTC)

Electric engines can be split up very easily and effective down to multiple smallest size engines instead of one big because they are very simple constructions in essence. Combustion engines on the other hand are way more complicated because they need lots of additional parts like an injection system, a starter, often even additional special parts like a choke for starting cold etc.. Thus its much harder to replace one big combustion engine with multiple small ones.

Now in addition to that ist much easier and more effective to just lay two electric cables instead of adding a transmission to every location you want a central motor's power to be split up to. Thats why for example each of the 6 Curiosity (rover)'s wheels has its very own engine. --Kharon (talk) 00:18, 15 January 2016 (UTC)

History of puberty blockers

When was the first one developed? When did they become widely available? -- Brainy J ~✿~ (talk) 04:44, 14 January 2016 (UTC)

This article from 2006 [33] is the earliest ref in our current article. It cites this 1983 article [34] describing a different treatment of precocious puberty in 1983. I do not know if that was the first puberty blocker, but it's a start. If you need access to these articles, ask at WP:REX. Sorting through the citations of the 1983 paper and our precocious puberty article (or even just reading them it carefully, which I did not) may answer you questions more conclusively. SemanticMantis (talk) 16:17, 14 January 2016 (UTC)

Platinum electrode

What electrochemical cell voltage would be considered as a safe upper limit, bellow which oxidation hence dissolution of the platinum electrode is negligible? I'm running an electrowinning setup using a complex leachate, containing multiple components. I've been using 4.0 V, but that is a complete guess. Plasmic Physics (talk) 10:53, 14 January 2016 (UTC)

Standard electrode potential (data page) indicates the standard reduction potential for Pt²⁺ --> Pt is +1.188 volts. --Jayron32 16:08, 14 January 2016 (UTC)

I don't think it works that way, besides, I've had no obvious degradation of the anode. Plasmic Physics (talk) 20:37, 14 January 2016 (UTC)

What's the difference between transvestites and transsexuals?

When you see one can you tell, this is a transvestite but not transsexual? Are transvestites just part-time transsexuals?--Scicurious (talk) 13:57, 14 January 2016 (UTC)

We do have articles transvestite and transsexual - the former could use some work though. It sounds from that like "transvestite" is coined not really that long ago to mean cross-dressing, but its creator used it to refer to more long term transsexuality? Wnt (talk) 14:35, 14 January 2016 (UTC)

I'd say transvestism is about behavior and transsexualism about gender identity. --Llaanngg (talk) 15:27, 14 January 2016 (UTC)

When you just see anyone, you can't necessarily tell that much about them. Sexual orientation and gender identity are not inherently visible. Note also that trans people can be homosexual or heterosexual or bisexual or even asexual. Gender identity and sexual orientation and other factors combine to a lot of different sorts of people. You may also enjoy background reading on notions of gender and sex, as well as cisgender, transgender, genderqueer, or attraction to transgender people.

Some people choose to present a visual image that helps signal their status to others, while other people do not. The general notion of this in biology is Signalling_theory. Depending on where you live, you may have seen many transsexual or transgender people and not known it, e.g. Passing_(gender).

To answer your question directly - If you see someone who you think is cross-dressing or transsexual, the only way to know for sure if they identify as either is to ask them. But that is very rude. If I were to meet you as a stranger in public, I wouldn't ask who you like to fuck or why you wear the clothes you wear, and I'd think you'd prefer it that way :) In the USA at least, the polite thing to do is to reserve questions of this nature for people with whom we already closely familiar. SemanticMantis (talk) 15:59, 14 January 2016 (UTC)

Our article on Transvestism says that it is, regardless of its underlying motivation, a behavior, dressing as a member of the opposite sex. Our article Transsexual defines the term as referring to those who identify with a gender inconsistent with their physiological sex, and wish to physically change to the gender with which they identify.

How to tell the two apart? You can't. Transsexuals at some point often are transvestites - especially after sex reassignment therapy or other medical interventions aimed changing the patient's ostensible sex to what the patient identifies with.

Transvestites are not "part-time" transsexuals. A transsexual is always a transsexual, never "part-time." Now, the reverse is possible - a transsexual may cross-dress only part of the time. Or, like the movie director Ed Wood, a transvestite may be heterosexual but have comfort issues which compel him or her to dress as the opposite sex. It's worth mentioning that women in Western countries often wear male attire without being called "transvestites." In other countries today, this is not only transvestism, but culturally deprecated and even illegal. loupgarous (talk) 21:54, 14 January 2016 (UTC)

I wouldn't say that after sex reassignment transsexual are often transvestites. Quite in contrary. They are physically, mentally and legally a member of their target sex, who will very probably dress like a typical member of this sex.

I also would not say that Western woman wear male attire. Attire worn by men became unisex or with no gender mark. Women in trousers, box shorts, shirts, suits are all wearing these unisex clothes. Denidi (talk) 01:55, 15 January 2016 (UTC)

popping zits

In nature are zits supposed to be popped or left alone? Which is most beneficial from an evolutionary standpoint? — Preceding unsigned comment added by 62.37.237.15 (talk) 20:15, 14 January 2016 (UTC)

Check out danger triangle of the face. It is rare, but popping acne or furuncles in that area can lead to infections that spread to other areas, causing Cavernous_sinus_thrombosis, or to the brain, causing meningitis. SemanticMantis (talk) 20:41, 14 January 2016 (UTC)

This is definitely one of those "No Medical Advice" questions. We aren't allowed to offer advice on diagnosis, prognosis or treatment of medical conditions...so we can't advise you on how to treat pimples - even if the treatment is something as seemingly mundane as popping/not-popping them. Beware of arguments from an evolutionary standpoint - evolution may not care whether you wind up with smooth skin or something that looks like the surface of the moon. These things tend to be cultural in nature. SteveBaker (talk) 20:57, 14 January 2016 (UTC)

I'm not asking for medical advice, I just asking what nature intended. How is this any more medical advice than asking if nature intended broken bones to heal or not? I don't have zits, I'm not asking this for myself. I'm asking generally as a scientific question. 62.37.237.15 (talk) 21:08, 14 January 2016 (UTC)

Or to put it a different way; have the millions of years of human evolution favored popping or not popping zits, from a purely evolutionary (therefore survival) standpoint. No cultural issues needed. 62.37.237.15 (talk) 21:12, 14 January 2016 (UTC)

Nature does not intend anything.

And apparently both zit-poppers and zit-non-poppers managed to survive. So, evolution did not made up her mind about this. But as said above, this is a bad perspective, you can be in a social environment that strongly prefers the one or the other. In the same way as people might have their preferences toward deformed/normal feet, or tanned/fair skin, thin/fat bodies. --Scicurious (talk) 21:52, 14 January 2016 (UTC)

Quick and dirty answer? Pop your zits in the presence of a potential mate, and your chances of passing your genes on through sex drop precipitously. This answers your question regarding evolution. Popping zits would seem to reduce the popper's chances of transmitting his or her genes to future generations. That being said, previous posters' remarks about "zit-poppers and zit-non-poppers" managing to survive imply a genetic basis for the behavior which hasn't, as far as I'm aware, been investigated, much less proven. It's just a gross habit that would only get you laid if you found someone who thought it was attractive and was aroused somehow by it. Think that's ever going to happen? loupgarous (talk) 22:03, 14 January 2016 (UTC)

lol, I'm pretty sure that I could pop my zits (I rarely have them, yay yay for testosterone blockers!) in front of most of my mates (male or female) and they wouldn't really care. My ex-girlfriend didn't really have zits either, but I'm sure that she would have popped them in front of me, and we would still have great sex afterwards. Yanping Nora Soong (talk) 22:21, 14 January 2016 (UTC)

De gustibus non disputandam... loupgarous (talk) 23:50, 14 January 2016 (UTC)

From an evolutionary standpoint, nothing is "supposed" to do anything. Nature is not a conscious agent. The only question that makes sense is, "How does this behavior affect the fitness of the organism?" I suspect popping pimples might slightly decrease an organism's fitness, because it can lead to infection, but the risk is not that great, so I imagine the overall selection pressure is pretty tiny. --71.119.131.184 (talk) 22:16, 14 January 2016 (UTC)

I doubt that popping zits can lead to an non-treatable infection nowadays. Scicurious (talk) 22:32, 14 January 2016 (UTC)

This is a ref desk, what you doubt or don't doubt is completely irrelevant. Vespine (talk) 23:23, 14 January 2016 (UTC)

That's just an expression. I could have said: I don't have any ref at hand right now, but I don't believe popping zits can lead to an non-treatable infection nowadays. Scicurious (talk) 23:40, 14 January 2016 (UTC)

That's exactly the problem. Not having any references but an opinion. A reference like [www.webmd.com/skin-problems-and-treatments/teen-acne-13/pop-a-zit Before You Pop a Pimple] from WDMed, a web-site I normally trust, collides with your assumptions. Denidi (talk) 23:54, 14 January 2016 (UTC)

I have myself on occasion offered a "I doubt something", but ONLY if the thread had not already had some relevant replies leading towards an opposite conclusion AND even more critically was not related to something that could have serious negative health repercussions. Vespine (talk) 00:51, 15 January 2016 (UTC)

Eka-, dvi-, tri-, and chatur-

"Eka-" is sometimes used as a prefix meaning "one row below in the periodic table". For example "ununtrium" is sometimes called "eka-thallium". Have "Dvi-", "Tri-", and "Chatur-" been used in similar ways?? These are the corresponding prefixes for 2, 3, and 4. Georgia guy (talk) 22:07, 14 January 2016 (UTC)

See Mendeleev's predicted elements. At least rhenium was called dvi-manganese (because eka-manganese, i.e. technetium, wasn't known either). Icek~enwiki (talk) 00:22, 15 January 2016 (UTC)

solubility of zwitterions in organic or lipophilic solvents

What are the guidelines for whether a zwitterion (especially an alpha amino acid -- but not necessarily one of the 20) will be soluble in solvents like dichloromethane or cyclohexanol? (Chloroform or ether is also fine, I guess, since solubilities in them are tested more often.) For example, L-DOPA at its isoelectric point is weakly soluble in water, but insoluble in ether or chloroform. Which puzzles me -- how are you supposed to do acid-base extraction of an amino acid into an organic solvent if an amino acid at its pI is weakly soluble in water but even less soluble in an organic phase? Would adding a phase transfer catalyst like tetrabutylammonium bromide increase the solubility of AAs in organic solvents at the pI -- or would it reverse as soon as you tried to separate the two phases? Yanping Nora Soong (talk) 22:27, 14 January 2016 (UTC)

This article refers to the use of lanthanide complexes to not only extract zwitterionic amino acids, but to do so by chirality of the desired amino acid.

And this article discusses reverse micellar extraction of zwitterionic amino acids.

The Google search term I used to locate these articles is "extraction of amino acids zwitterions," and many articles came up which you may want to look at for more information. loupgarous (talk) 00:05, 15 January 2016 (UTC)

Thanks! That's a more useful keyword. I'm not sure if I'm understanding these "ion exchange" methods correctly (especially since I don't have any ion exchange resins at the moment). I'm looking at patents such as this one. [35] Does this patent imply I can dissolve zwitterionic amino acids in most weakly polar or non-polar organic solvents by dissolving 2M (or 1% w/w) quartenary ammonium salts (like TBAB) into the organic solvent? Then I add the sodium salt of my amino acid (whether in the aqueous layer or as a dry salt) -- sodium bromide precipitates and I get a solution of the tetrabutylammonium salt of my amino acid in cyclohexanol or dichloromethane? I'm trying to make sure I'm understanding these procedures correctly. Yanping Nora Soong (talk) 01:14, 15 January 2016 (UTC)

The patent specifies "a substantially immiscible extractant phase comprising an amine and an acid, both of which are substantially water immiscible in both free and salt forms." Now, you're proposing (if I understand you correctly), to use quaternary ammonium salts, which are generally cationic detergents and very miscible in water. So you've already departed from the procedure defined in the patent, I think.

I'd encourage you to read the sources the Google search "extraction of amino acids zwitterions" turns up for ideas that fit your specific requirements more closely. loupgarous (talk) 05:29, 15 January 2016 (UTC)

In the "previous art" section they discussed the use of trioctylmethylammonium chloride. There is also mention of others using Aliquat 336, which AFAIK is often interchangeable with TBAB for phase transfer catalysis reactions. I have tetrabutylammonium bromide (TBAB). AFAIK, TBAB has a high critical micelle concentration, so it's pretty inaccurate to call it a detergent and also why it's favored for PTC. They actually mention the use of quats in that patent (as well as their organophosphate anionic counterparts), and I think they actually use them, they just combine quats, lipophilic anions and other surfactant stabilizers in the same organic phase. Yanping Nora Soong (talk) 08:48, 15 January 2016 (UTC)

Do amino acids sometimes combine in water?

I mean without all the hardware that a cell has, that allows to combine them into proteins, do amino acids sometimes combine by chance just by bumping into each other if you shake the water they float in for long enough? --Lgriot (talk) 22:32, 14 January 2016 (UTC)

If you ask whether that happens at all: Definitely, even if you don't shake. The molecules are in thermal motion anyway. And conversely, peptides sometimes break apart (i.e. are hydrolyzed) without enzymes catalyzing this reaction.

Maybe more interesting is the question of what fraction of amino acid molecules can be expected to be free amino acids and which fraction will be in peptides. See chemical equilibrium for a general introduction. For a dilute solution of amino acids, the equilibrium state has far more free amino acid molecules than peptide-bound ones. In a very concentrated solution, water for hydrolysis is not so abundant, and you'll find a higher fraction of peptides at the equilibrium.

Icek~enwiki (talk) 00:31, 15 January 2016 (UTC)

Short-answer: they don't. Peptide bond formation is much harder than just simple Fischer esterification-- for the issue that if you try to catalyze the reaction by deprotonating the amino group (activating the nucleophile), you deactivate the carboxylic acid as an electrophile (it becomes a carboxylate), and if you try to catalyze the reaction by acid (activating the carboxylic acid group), you deactivate the nucleophile (the amino group gets protonated, losing its lone pair). You can create an amide or peptide bond by heating your reagents at 250C, but the problem is that these harsh conditions often cause a lot of side reactions to occur, at a risk of degradation or oxidation of the sidechain. Yanping Nora Soong (talk) 00:57, 15 January 2016 (UTC)

Selective peptide coupling is an expensive task and an entire industry of its own: see peptide synthesis. Yanping Nora Soong (talk) 00:59, 15 January 2016 (UTC)

I'm reminded of the Urey-Miller experiment. If there were a simple way to string those amino acids into peptides, that would be very exciting, but it's not really so. Now by contrast, I remember hearing that polymerizing hydrogen cyanide gives rise to actual polypeptides (once water is added) - here's a source [36] but I'm not sure it's the definitive one. Now as peptide bond says, water will spontaneously hydrolyze the bond on a very slow time scale, liberating substantial energy; and this implies that the reverse of the reaction does occur, but because of the energy difference, it would occur in a very, very small proportion of the total molecules (I'm afraid I'd have to reread Gibbs free energy, at least, to try to guesstimate what proportion that is.... but AFAIR 8 kJ/mol is a biological way to say "fuggedaboudit") Wnt (talk) 01:26, 15 January 2016 (UTC)

Polyaspartic acid can be accomplished by simple pyrolysis of aspartic acid followed by hydrolysis (easy undergrad lab experiment). The pathway for this polypeptide is not general for all the encoded amino acids, requiring at least some aspartic acid- or glutamic acid-like component (see also [37] that proposes this sort of reaction as relevant to prebiotic processes). DMacks (talk) 04:29, 15 January 2016 (UTC)

Remember, thermodynamic energy release is different from the kinetic activation barrier.

But if dG = -RT ln K = -8 kJ/mol, then K = e^(-dG/RT) = e^(8 kJ/mol / (298 K * molar gas constant)) = e^(3.22) = ~25

So the equilibrium constant for hydrolysis is around 25. The equilibrium constant for the reverse reaction would thus be around ~4%. This is actually kind of impressive, but the energy barrier is much higher -- I would guesstimate around 20-30 kcal/mol -- or around 80-120 kJ/mol. Yanping Nora Soong (talk) 08:56, 15 January 2016 (UTC)

January 15

Is there such as "aspiration center" in nerve system?

(I'm not surely back) Like sushi 49.135.2.215 (talk) 00:48, 15 January 2016 (UTC)

I don't quite understand your question, further information about the context would be needed. Maybe what you are looking for is an aspiration center. This is a physical location in a hospital where some medical procedure like needle aspiration biopsy) is performed. --Denidi (talk) 01:20, 15 January 2016 (UTC)

Is there such as "motive entropy"?

(I'm not surely back) Like sushi 49.135.2.215 (talk) 00:49, 15 January 2016 (UTC)

As above, the question is difficult to understand. Motive is usually a term used in law or psychology while entropy is a term usually used in physics, specifically thermodynamics. I have not come across those two words being used together to describe anything. If this misses your question entirely, you could try asking the question in your native language and someone might be able to translate it for you. Vespine (talk) 04:59, 15 January 2016 (UTC)

Two seconds of googling reveals it to be a phrase used by Carnot, hence something to do with thermodynamics. Greglocock (talk) 08:28, 15 January 2016 (UTC)

Motive can also be an adjective meaning "relating to motion and/or to its cause". Just like a locomotive is not generally a reason why loco people commit crimes, it's unlikely that "motive entropy" has anything at all to do with the law or psychology term. ;) --Link ^(t•c•m) 11:42, 15 January 2016 (UTC)

Norovirus and Pathogenic Escherichia coli

Does immersion in boiling water inactivate these two pathogens, and how long does it take? Edison (talk) 05:09, 15 January 2016 (UTC)

Yes, I found this article has some details. All common enteric pathogens are readily inactivated by heat, although the heat sensitivity of microorganisms varies. It appears that for most viruses they take just several seconds (~10 seconds) to be inactivated in boiling water. Just keep in mind that just putting a potato (for example) into boiling water for 10 seconds doesn't guarantee all virus will be inactivated. There could be a virus caught in a crack or cavity that is too small for water to get into, and the potato can act like a heatsink for long enough to cause the virus not to reach a high enough temp. Vespine (talk) 05:53, 15 January 2016 (UTC)

Agreed. This is why food has to be cooked right through. One more thing to mention is that even though cooking may kill the pathogenic organisms, it won't necessarily inactivate their toxins. -- The Anome (talk) 08:42, 15 January 2016 (UTC)

Douglas Baldwin's rather wonderful book on sous vide has both the full pasteurisation time/temperature tables for the internal temperature of the food (in the section linked), and timings for how long it would take to reach those temperatures given the meat, thickness, and water bath temperature (in the individual sections for the meats). E coli is considered in the beef, lamb and pork section. The point about toxins is a very valid one - and there are some pathogens (such as Clostridium botulinum) which will just spore up at cooking temperatures, and then continue to reproduce when the temperature drops. MChesterMC (talk) 09:22, 15 January 2016 (UTC)