Wikipedia:Reference desk/Archives/Science/2014 December 30

= December 30 =

Can a dog's toe cut off when cutting nail?
When cutting a dog's nail, can a person cut so far beyond the quick (or kwik) that the bone is cut off or part of the bone is cut off?174.3.125.23 (talk) 02:32, 30 December 2014 (UTC)


 * I suppose so, as long as the tool can open wide enough. However, you'd need to be seriously incompetent to do that.  That's a bit like accidentally cutting off an ear when cutting hair. StuRat (talk) 03:25, 30 December 2014 (UTC)


 * The word "quick" literally means "alive", and cutting that part of the dog's claw can cause it great pain, bleeding, and necessitate a trip to the hospital. I am not quite sure what anyone would be doing cutting the claw to the quick, not to mention beyond. μηδείς (talk) 19:00, 30 December 2014 (UTC)


 * A decade or two ago (when my family had cats) I remember reading in cat magazines that the process of declawing (which for cats is/was rarely performed in the UK and is now illegal, but apparently is/was used more elsewhere) involved the deliberate removal of all or part of the end bone on each toe. Presumably this could also be applied to dogs deliberately, and an incompetent claw-clipper could presumably do this accidentally. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 14:27, 31 December 2014 (UTC)

Which part(s) of North America has/have a climate most like New Zealand's?
Just curious. It's a big place with a lot of variation in climate, so I figure there's probably at least one region where it's reasonably similar to NZ. --203.96.145.52 (talk) 05:57, 30 December 2014 (UTC)


 * There will be many places in the US that match one or two aspects of New Zealand's climate. For example, there will be many places whose rainfall matches the rainfall in certain places in New Zealand; there will be places in the US whose winter minima match the winter minima in certain places in New Zealand. But New Zealand is a small island and the US is a continent so I doubt there is any place in the US whose climate throughout the year is close to the climate throughout the year in some place in New Zealand. Dolphin  ( t ) 06:06, 30 December 2014 (UTC)


 * The US has lots of islands, including the Hawaiian Islands (probably too warm) and the Aleutian Islands (probably too cold). There are many islands in between, like Catalina, Block Island, and Long Island, so you should be able to find one that matches parts of NZ fairly well.  This islands around Seattle might be a good match.  There's also Vancouver Island just across the border in Canada. StuRat (talk) 20:14, 30 December 2014 (UTC)

NZ may be small, but I'd say that the variation in climate for NZ is so large as to render the question meaningless. East coast is dry, west coast is very wet. North of the north island is as warm as sydney, south of the south island is a tad chilly. Greglocock (talk) 06:28, 30 December 2014 (UTC)


 * Climate classification schemes can give you one answer. The most commonly used scheme is the Koeppen classification. The most populated parts of New Zealand have a Cfb climate in this scheme, which is not found to any significant extent in the U.S. Other places with Cfb climate include northern and western Europe. As Greglock notes, climate across New Zealand is rather variable so this does not apply everywhere in that country. Short Brigade Harvester Boris (talk) 16:36, 30 December 2014 (UTC)


 * The temperate rainforests of the West Coast of New Zealand should be similar to some of the Pacific temperate rainforests, being at similar latitudes and both being rain forests.--Wikimedes (talk) 19:41, 30 December 2014 (UTC)

how does previously boiled water differ?
Preparation instructions on something call for 'cold boiled water (you can use spring water)'. Huh? Why - how does the fact that water has been previously boiled change it? Why doesn't it just say 'cold water'? (And it definitely calls for cold water, not water you bring to a boil from a cold status, which I thought might be a reading for 'cold boiled water.' I know this both due to the fact that it's a cold meal and also the fact that the translations don't call for boiling.)  By the way this is like two sachets of a powder you mix into a pudding, and like oats or granola, respectively. the product is this one: http://www.mokate.eu/our-brands,yogocrunch,205.html 212.96.61.236 (talk) 07:39, 30 December 2014 (UTC)


 * Previously boiled pure water is no different from unboiled water, chemically or physically. Plasmic Physics (talk) 08:07, 30 December 2014 (UTC)


 * This sounds like an instruction to reduce the amount of air suspended in the water, which is what will happen if you boil it or use bottled water rather than tap water. I couldn't find any reference to "cold boiled water" in the above link. What is it that is being prepared? Can you point to an example of this instruction in context?--Shantavira|feed me 08:25, 30 December 2014 (UTC)


 * Yes, PP's pure water is rare outside the laboratory, so there is a minor difference in that boiling releases nearly all the dissolved air in tap water. I can see no reason why dissolved air would be a problem in the preparation.    D b f i r s   08:34, 30 December 2014 (UTC)


 * Boiling tap water can also lower the concentration of any minor disinfection by-products that result from treatment processes, which could otherwise interfere with food preparation chemistry. Plasmic Physics (talk) 09:04, 30 December 2014 (UTC)


 * Yes, it will get rid of any volatile contaminants, but might concentrate others. It doesn't get rid of the "chlorine taste" that I notice in most UK tap waters.  (I'm not sure what residue this is -- obviously not chlorine gas.)    D b f i r s   09:43, 30 December 2014 (UTC)

So regarding what it is, the product is a pudding (that you mix cold by adding 100 ml of water and mixing well), and then after mixing you mix in the other packet, which is a much larger packets of oats or granola or something, to make a delicious quick thing that I wanted to describe as a parfait. (But I guess this word is wrong, and parfait must have frozen ice cream etc.) There are pictures on the front of the packaging in my earlier link.

Returning to 'cold boiled water', here are thousands of pages with the words "cold boiled water" and pudding, apparently all preparation instructions: https://www.google.com/search?q=%22cold+boiled+water%22+pudding Obviously pouring cold water is hundreds of times faster and easier than taking out a pot, pouring cold water into it, putting it on the gas, turning on the gas, waiting for it to boil, removing it from heat, and waiting for it to cool down again all the way to cold status. (I mean literally hundreds, if not thousands, of times faster - a tenth of a second versus ten minutes. In the case of this preparation for example, waiting for the boil and cooling down would be 90% of the preparation time.  So unless there is some use, I doubt it would make it into these otherwise quite simple recipes.  The product in question is also particularly simple and convenient.  There must be some chemical reason.  91.120.14.30 (talk) 10:03, 30 December 2014 (UTC)
 * If the British can make parfait of liver and the Americans can use yogurt, I think yours is as valid. Rmhermen (talk) 15:42, 30 December 2014 (UTC)
 * The usual reason for boiling water before use and allowing it to cool is to kill any bacteria it may contain. Sugary foods made up with cold ingredients (or made with hot ingredients and allowed to cool) and then left to stand for a while, are a very good medium for growing bacteria, so you want to start off with a minimal amount of bacteria present. Babies are given cooled boiled water for the same reason. Richerman    (talk) 10:45, 30 December 2014 (UTC)
 * I can see the reason for boiling water for young babies whose stomachs may not be sufficiently acidic to kill bacteria, but most tap water in the civilised world contains only a few relatively harmless bacteria, and the food (or the boiled water), if left uncovered, it will gain a greater number of bacteria from the air. Can bacteria be the only reason for the recipe?    D b f i r s   12:28, 30 December 2014 (UTC)
 * This is not convincing at all. Why would packaging for something I prepare and eat in 5 minutes care in the slightest whether my tap water contains some bacteria?  What, is the pudding such a potent agar that in 5 minutes any bacteria present in tap water would multiple by a trillion?  Why doesn't it ask me to treat it with sterile gloves then?  Since the product is intended for adults, this explanation is completely unconvincing.  Nothing else you mix with water mentions this. 91.120.14.30 (talk) 14:34, 30 December 2014 (UTC)


 * There's probably a customer service number on the package somewhere; you could call them and ask. You could also prepare it both ways, and see if you notice a difference in taste, texture, etc. If you do either of these, it would be a kindness to write back here and tell us what they said (or what you discovered).  My only contribution to the guessing game is: is it possible this is intended for camping, or some other use where the quality of the water would be suspect? --Floquenbeam (talk) 14:43, 30 December 2014 (UTC)
 * That's an excellent guess! (camping).   Sure, if I figure it out I'll tell you.  For what it's worth I had ignored the silly suggestion, used cold water, and it tasted fine.  But one thing is - what do you make of all the Google links I showed showing the presence of this phrase in recipes?  (and you can remove 'pudding' from it and get different recipes.)  It certainly must have some effect.  I think the earlier guess of removing dissolved air was a good one. 91.120.14.30 (talk) 15:21, 30 December 2014 (UTC)
 * Worth noting the pudding in question appears to come from Poland. From various searches, it appears that it may be common that water from the tap there is perceived as unsafe. To be clear, I'm not saying it is unsafe but rather than it may be a common perception by locals, so bottled or boiled water is commonly used even just for drinking. This isn't particularly uncommon, e.g. from what I can tell it may be the same in the Czech Republic (where I mistakenly originally though the pudding was from) or in Malaysia (there is perhaps a bigger question over the water quality there but I suspect it is safe, at least in terms of anything that boiling would help with in urban areas). Of course it isn't normally necessary to say "cold boiled water", locals will already guess what to do. One possibility is the manufacturer may want to encourage the use of tap water rather than bottled water considering it harmful to the environment or something, from what I can tell bottled water tends to be used for drinking more than boiled water although I don't know what's used in uncooked food preparation. Alternatively, if the instructions you're referring to are in English, it maybe the manufacturer (or rather whoever was writing the instructions) doesn't really think of tap water as ever really safe and wanted to make sure their English speaking customers didn't do dumb stuff. (I can say when I first came to NZ, I found drinking water directly from the tap weird. I found the same when I went to Singapore than Malaysia and once tried the same, even though I'm even more convinced the water there is safe.) A final possibility is that the manufacturer is ultra set in the belief tap water is unsafe and wanted to warn even Polish people to use boiled water (I think it's sometimes true people wouldn't think of drinking water straight from the tap, yet will blindly use it in food prepration even when the food is uncooked and they're drinking a lot of it). As for the search results, well many of them look to similarly be stuff written by people from places where there may be the same perception. Also, in terms of my earlier point, puddings, cold drinks and powdered milk are a few of the cases where you may use a fair amount of water in food preparation which will be consumed in without heating so for people with such a perception it's somewhere it's likely to come up. (It also comes up with ice, but there the water doesn't have to be cooled before.) I have seen milk powders with a more nuanced warning (suggesting you used cold boiled water if you aren't sure of the water safety). Nil Einne (talk) 17:35, 30 December 2014 (UTC)


 * Some thoughts:


 * 1) Let water sit to improve the taste. This let's volatile chlorine related compounds evaporate.  I suggest leaving it in the fridge in a sealed glass bottle overnight.  (The glass prevents chemicals from leaching into the water from a plastic container.)  Any food made with such water may taste better than fresh tap water.


 * 2) Lawyers often require frivolous warnings. Consider that if somebody leaves the parfait out for a day and then eats it, and dies as a result, the lawyers suing the company might argue "If only they had said to boil the water first, then the bacteria count would be so low to start, that it wouldn't have grown to a fatal level by the time it was eaten".  This is why Q-tips contain a warning to never put them in your ear, even though that's the only reason to put a cotton ball on the end of a long stick in the first place. StuRat (talk) 17:50, 30 December 2014 (UTC)


 * There are plenty of uses for cotton swabs besides the silly usage of sticking them in your ears. Manufacturers presmuably know this is the most common usage, but beyond the question of whether they should, it's also unclear what they could do to stop such misuse. Nil Einne (talk) 18:14, 30 December 2014 (UTC)


 * The obvious answer is to sell cotton balls instead. Can you think of any reason the cotton needs to be on a stick, other than to fit in the ear ? StuRat (talk) 18:43, 30 December 2014 (UTC)


 * Yes, actually. Cotton swabs can be used for applying liquid or powder to a surface (makeup, ointment, or a cleaning solution.) A tiny cotton ball on a stick allows you finer control in applying it, and keeps whatever you are applying off your fingers.--Srleffler (talk) 09:05, 31 December 2014 (UTC)


 * ObPersonal: another use is to apply clove oil to a sore tooth or gum (it tastes foul, so you don't want to be splashing it around your mouth too indiscriminately). {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 14:34, 31 December 2014 (UTC)


 * Indeed, StuRat's comment is just weird. Even if you really can't imagine other uses for cotton buds despite having lived until adulthood with all the life experiences and seen and used the cotton buds for some purpose (even if it is just cleaning your ears), one would have thought you can imagine why it would work better in some cases for some of the uses mentioned in our article (which I presume was read before asking the question). Still if StuRat is still unable to imagine, they could tell all these people they're doing it wrong and should use cotton balls instead       (comment only)          (probably described in video but not shown, is in description though)  (they use cotton buds & cotton balls for related purposes, n.b. the purpose isn't for application!)   . (Okay the last 3 or so are a bit weird.) Of course this is ignoring speciality cotton buds like those mentioned in our article or  which may not imply a usefulness for ordinary cotton buds, but do speak to there being a usefulness for having a cotton bud or cotton on a stick compared to cotton balls. (N.B. I didn't check carefully enough that all the previous uses were ordinary cottons buds although  they were shown in the videos except perhaps for the fishing one and the one without video and where noted.) Nil Einne (talk) 18:53, 31 December 2014 (UTC)


 * For anyone else confused by the term "cotton bud", it's apparently British English for what Americans call a cotton swab, or a Q-tip. StuRat (talk) 20:05, 31 December 2014 (UTC)
 * Summary of chemical effects when boiling natural water for a short time: (1) Killing of many microbes (2) Expulsion of atmospheric and other dissolved gases such as oxygen, nitrogen and carbon dioxide (3) Expulsion or destruction of trace amounts of many natural or industrial compounds that are volatile e.g. esters and alcohols (3) Depending on the exact composition (Ca, Mg, bicarbonate) there could be radical changes in the carbonate chemistry. This could have a profound effect on pH. Captainbeefart (talk) 06:41, 3 January 2015 (UTC)

What is the difference between adverse reaction and side effect?
185.13.195.173 (talk) 13:45, 30 December 2014 (UTC)


 * I'm not a doctor, but how I would understand the terms as a layperson, is that an adverse reaction is unusual, unexpected and specific to a person. For example, you could be allergic to the medicine!  you have to completely stop taking it, you react very badly to it.  You're reacting quite badly to the medicine itself.   Whereas, 'side' effect, as the name implies, is secondary.  It could even apply in 100% of cases - a side effect of caffeine pills is that you will urinate more as it's a diuretic.  It's a side effect because nobody cares about it, it has nothing to do with the reason for the bill.  it's not the primary effect.  I hope this shows most of the connotations.  91.120.14.30 (talk) 15:45, 30 December 2014 (UTC)


 * Yes, side effects can be positive. For example, it is claimed that a 2012 review of seven studies published in the journal Breast Cancer Research and Treatment showed that metformin [prescribed for diabetes] is also linked with a 17 percent lower risk of breast cancer. ( Disclaimer: example for illustration only; I don't know how accurate this claim is. )   D b f i r s   16:39, 30 December 2014 (UTC)
 * A good (and uncontroversial) example of a beneficial side effect is Viagra, which was originally intended to treat high blood pressure. Tevildo (talk) 17:12, 30 December 2014 (UTC)


 * Side effect is the more general term, and it usually connotes expected and mild symptoms like drowsiness from an antihistamine that do not cause a doctor to discontinue the prescription. Adverse effects are rare, severe, and possibly life threatening side effects like allergic reaction, anaphylaxis, and liver damage that cause one to stop using the medicine.  Here is some basic info from the US FDA. Note that many of the supposed side effects you hear or see in drug commercials in the US are not really side effects, but any symptom that is reported by those using the drug, like sleepiness or insomnia for sleeping pills, and "delayed back ache" for Viagra (in other words you had sex that was too vigorous). See also, Happy Fun Ball. μηδείς (talk) 17:23, 30 December 2014 (UTC)


 * I've also seen "side effect" used to describe the main effect. For example, insulin came with a warning that it may cause low blood sugar. StuRat (talk) 17:54, 30 December 2014 (UTC)


 * Yes, this is due to the changes in FDA regulations in the 90's at the same time they started allowing things like melatonin to be sold as "food supplements". Basically, any effect reported over a specific statistical threshhold will be mentioned, like a stool softener causing diarrhea.  Then they will mention the "rare side efects" which are important because they are clinically serious, like "priapism".  Then they will mention things like, if you stop breathing, cease taking your one-a-day pill and call a doctor, as if you'd take a second pill or be able to call your doctor. See this commercial contemporaneous with the change in FDA regulations.μηδείς (talk) 18:46, 30 December 2014 (UTC)

Graph Axis labels
When labelling graphs, why do some people say it's incorrect to put units in brackets. For example, "time (s)". They claim the correct label is "time /s". 176.251.149.108 (talk) 14:56, 30 December 2014 (UTC)


 * A graph is just a way to communicate information. If it clearly and accurately communicates the information to the reader, then it succeeds in doing its basic job. All else is just "style". Labeling an axis with quantity/unit is just one way of stating what the quantity and unit are. It might have some mathematical elegance to it: quantity/unit is dimensionless, matching the unit-less labels on the graph, but this does not do anything more or less than an equivalent textual description. Insisting that there's only one correct way to do it is, IMO, just stubbornness. --98.114.98.174 (talk) 15:45, 30 December 2014 (UTC)


 * While I don't disagree with all of what 98 said, following standard mathematical/algebrical convention seems to be the main rason some sources including the SI recommend using /s rather than (s)  Nil Einne (talk) 16:53, 30 December 2014 (UTC)


 * The first of those links, the BIPM document, does not specifically recommend this style over others; it just says it's permissible. However, its author seems to think that the only legitimate alternative is to repeat the unit explicitly on each tick.  The alternative mentioned by the original poster, "Time (s)", is not even mentioned. --65.94.50.4 (talk) 18:57, 30 December 2014 (UTC)
 * Since it only mentions one style, that does imply it's recommending it. And it does mention brackets and parenthesis in a few places, but not in relation to graphs. (It's probably fair to say they don't consider it a major issue, since in cases where there are major common styles which aren't recommended, they often do mention that.) Nil Einne (talk) 14:11, 2 January 2015 (UTC)


 * Parentheses are often used to indicate an alternate unit, so it might say "Speed m/s (ft/s)". StuRat (talk) 17:56, 30 December 2014 (UTC)


 * We are not talking about "alternate units". --65.94.50.4 (talk) 18:57, 30 December 2014 (UTC)


 * Yes, but consistent usage of parens means you would only use them when you have alternate units. StuRat (talk) 20:18, 30 December 2014 (UTC)


 * I imagine the pointy heads are trying to claim that a graph is a plot of numbers, and so they are non dimensionalising the measurements to numbers by dividing by the units. As someone who works with data for 50% of the week, i'm just glad when the units are mentioned. I'd add that if the pointy heads were really doing it properly they'd be plotting dimensionless variables, such as Re, otherwise they are kidding themselves, there is still an implicit assumption about which system of units they are working in. Greglocock (talk) 20:12, 30 December 2014 (UTC)


 * If the quantity being graphed is time, and is measured in seconds, "/s" could be confusing, as the "/" sign suggests division, i.e. s-1, which is a unit of frequency. So I'd avoid the "/" sign as it introduces ambiguiety. --NorwegianBluetalk 21:28, 30 December 2014 (UTC)


 * Yes the "/" sign does represent division: time divided by seconds yields a (dimensionless) number. There is a logic to the "/" convention, but the bracket notation is perfectly clear so it's pedantic to object to it. --catslash (talk) 23:20, 30 December 2014 (UTC)


 * But it is also pedantic to do it. For instance suppose I label my axis 'speed /mph' on one graph, and 'speed /kph' on another. The actual numbers I plot are different so the pointy head argument fails. What I should do is plot 'speed /c' and then it doesn't matter what units I am working in, 'c' being the speed of light.Greglocock (talk) 20:51, 31 December 2014 (UTC)


 * That's just changing units. If you keep the mph and kph you'd still have different numbers even if you divide by "c".  If you want the graphs to be easy to compare, you would need to plot something like speed/max speed (or percentage of maximum speed).  ( If you need to compare graphs, then the logical thing is to use the same units on both, of course. )    D b f i r s   21:14, 31 December 2014 (UTC)

Asphalt question
What is the main difference between the asphalt used on high speed roads and those used on city roads? — Preceding unsigned comment added by 176.251.149.108 (talk) 19:16, 30 December 2014 (UTC)


 * “main” is a bit subjective. From Alaska to California there are different conditions to be taken into account. See if Asphalt concrete goes to answering your inquiry.--Aspro (talk) 20:09, 30 December 2014 (UTC)


 * Some roads have different base course, pending on vehicles weight to prevent ruts. A higher load for the road occurs at stop points. -- Hans Haase (有问题吗) 20:20, 30 December 2014 (UTC)


 * My dad having been a civil engineer, thinks that the main difference is that high speed roads are constructed using higher grade asphalt, graded according to the Marshall stability system. This system rates the viscosity. Higher traffic flow also calls for a thicker asphalt layer. Plasmic Physics (talk) 21:16, 30 December 2014 (UTC)


 * why does it need to be thicker and more viscous? 176.251.149.108 (talk) 00:45, 31 December 2014 (UTC)


 * I'm just guessing here, but since asphalt is a Newtonian fluid, the higher vehicle speeds cause higher shear stresses. Therefore, the road surface deforms faster. Using a more viscous asphalt, means that it can handle higher shear stresses. Newtonian fluid dynamics. Higher traffic flow just means that the road wears out faster, meaning that a thicker layer makes it last longer. Plasmic Physics (talk) 04:50, 31 December 2014 (UTC)
 * Is it? I thought asphalt is viscous-elastic or shear thinning. 82.132.244.201 (talk) 13:47, 31 December 2014 (UTC)


 * Being a Newtonian fluid was part of the guess. My point is that the answer lies in the rheology of the asphalt. Plasmic Physics (talk) 21:11, 31 December 2014 (UTC)


 * Also, a big problem with asphalt is that it breaks apart starting at the edges, so better edge protection might be in order. StuRat (talk) 21:24, 30 December 2014 (UTC)


 * Ah, “it breaks apart starting at the edges”. Is that why so many geriatrics stick to the middle of the highway with their cruse control stuck on 55 mph -like their trying  to get back to the future?--Aspro (talk) 21:35, 30 December 2014 (UTC)


 * That would require 88 mph, and the only way they are likely to hit that is when they confuse the brake and accelerator pedals. :-) StuRat (talk) 22:42, 30 December 2014 (UTC)


 * Then they should just switch their speedometers to metric. 55 mph = just over 88 km/h.  So there!--65.94.50.4 (talk) 01:36, 31 December 2014 (UTC)

Why did you guys switch to back to the future references? how did 'it breaks apart starting at the edges' prompt this? 212.96.61.236 (talk) 02:34, 31 December 2014 (UTC)


 * No idea why Aspro did, but I just followed his lead. StuRat (talk) 05:47, 31 December 2014 (UTC)
 * And in case you don't know, 212.96.61.236, the informal convention on the Ref Desks is to switch to small text when we're either telling jokes inspired by the main text but not pertinent to actually answering the Original Post(er), or pursuing a serious but equally irrelevant digression. {The poster formerly known as 87.81.230.195} 212.95.237.92 (talk) 14:41, 31 December 2014 (UTC)
 * I'm guessing Aspro is referring to the fact 55 mph is no longer the maximum speed thoroughout the US as it was at a time (National Maximum Speed Law), yet some people may still drive at that speed even in places where the current limit is higher. Nil Einne (talk) 19:32, 31 December 2014 (UTC)
 * Tell you this. If one of these geriatrics did hit the magical 88's, then  they might find themselves back in 1885 with a Wells Fargo stage coach tailgating them instead of me,  with  the shot-gun yelling at them “Move over – you @% $Ж ** road hogs!” Rather than me sitting patiently  going beep beep on my little horn, which they probably can't hear, because if they are not completely stone deaf, they are probable listening  to something like  Ride of the Valkyries at 33$1/3$ RPM. Don't even try to tell me what that is equivalent to on shellac  I DO NOT  WANT TO KNOW!  Mind you, having said that, Black Sabbath played backwards at the same speed was interesting.Black Sabbath played backwards. I think I would probably play safe and stay in  the middle lane and away from those crumbly edges if I was listening to that. --Aspro (talk) 00:01, 1 January 2015 (UTC)


 * See also Rubberized asphalt which is sometimes used for noise reduction purposes. Alansplodge (talk) 17:37, 31 December 2014 (UTC)