Wikipedia:Reference desk/Archives/Science/2013 July 3

= July 3 =

Bluejays and cardinals
How are bluejays and cardinals related evolutionarily? Do they share a common ancestor? What is their recent most common ancestor? Also, is it legal in the United States to capture a SMALL wild animal like a blue jay or cardinal and keep it as a pet or as dinner, or would a person need a license no matter what? Sneazy (talk) 01:15, 3 July 2013 (UTC)


 * The easiest way for you to see how two organisms are related is to check the infoboxes in their articles. If you look at Cardinal, you will see: its kingdom is Animalia, phylum Chordata, class Aves, order Passeriformes, family Carinalidae, genus Cardinalis, and species Cardinalis cardinalis. Looking at Blue Jay, its kingdom is Animalia, phylum Chordata, class Aves, order Passeriformes, family Corvidae, genus Cyanocitta, and species Cyanocitta crostata. So the two are identical in descent down to the level of order: both are passerine.  They differ at the family level, with the Blue Jay being a corvid.
 * The legality of capturing, killing, or eating wildlife varies by jurisdiction, and in any case, we don't offer that sort of legal advice. - Nunh-huh 01:36, 3 July 2013 (UTC)
 * Indeed, but see Migratory Bird Treaty Act of 1918. Matt Deres (talk) 01:44, 3 July 2013 (UTC)
 * @Nunh-huh: Having written an undergraduate research paper on the evolution of a specific type of passerine birds, the lyrebirds, I am not sure what you are trying to imply in your post. All organisms interact on a species level. Although the hierarchical classification system is useful in taxonomy, it does little to answer the question of how bluejays and cardinals evolved from ancestral passerine birds. Sneazy (talk) 02:58, 3 July 2013 (UTC)
 * Your question contains no indication that you understood that both species were passerine birds; I was simply pointing you towards that information. You didn't ask how blue jays and cardinals evolved from ancestral passerine birds, you ask if they had a common ancestor. - Nunh-huh 22:06, 3 July 2013 (UTC)
 * Well, I was expecting a much more fuller answer. You know, one that has more substance. :P Sneazy (talk) 00:09, 4 July 2013 (UTC)
 * You got what the question merited. You're welcome. - Nunh-huh 00:37, 4 July 2013 (UTC)
 * No, I didn't. The recent most common ancestor can't be a broad category. Saying that blue jays and cardinals derive from passerine birds is like saying humans derive from the apes. It's not specific. So, I didn't get what the question merited. A better response would be to list an ancient passerine bird species that gave rise to the blue jay and the cardinal. Sneazy (talk) 18:37, 4 July 2013 (UTC)
 * In which case you are not going to get a good answer anyway--or not one better than "it would be the same as whatever animal is the common ancestor of the crow and the sparrow." Bird fossils aren't that well represented, and the passerines are so morphologically similar that classification is not certain, and all of bird classification has been under heavy flux for the past 25 years. μηδείς (talk) 19:03, 4 July 2013 (UTC)
 * Although classifying organisms by morphology is an useful method, it cannot be the only method, because morphology is really what an organism looks like, and looks can be deceiving. Since the two species are alive, I would probably suggest a DNA analysis on the blue jay and the cardinal and make a phylogeny based on the modified characters. Just because Mother Nature has made them morphologically similar doesn't mean that they are genetically similar. Maybe Mother Nature pressures the birds to evolve in a certain shape, because that certain shape is most advantageous for survival. Sneazy (talk) 23:55, 4 July 2013 (UTC)


 * They are not at all close within the passerines. Jays are quite close to crows within the crow superfamily.  Cardinals are close to sparrows in the sparrow superfamily.  (Search for cardinal and jay in our passerine article)  Keeping a Northern Cardinal can get you a fine due to the Migratory Bird Treaty Act of 1918.  If you want to keep a bluejay you will deserve whatever you get.  I would love to see a hybrid, however unlikely. μηδείς (talk) 03:15, 3 July 2013 (UTC)
 * 1. Where did you get that knowledge?
 * 2. It still does not explain how the two types of birds might have evolved or what might the specific selective forces be. Sneazy (talk) 03:32, 3 July 2013 (UTC)
 * That second question is very interesting, because as far as I am aware, "what might the specific selective forces be" is very rarely known, am I right? They are too many factors, and we haven't collected the data for most species. But maybe someone with better understanding of the science will correct me, and I will be very happy to hear what they have to say. --Lgriot (talk) 08:32, 3 July 2013 (UTC)

1) look at the article Passerine and the position of the corvidae and the cardinalidae within the taxonomy. (2) requires a treatise, μηδείς (talk) 16:33, 3 July 2013 (UTC)

Total solar eclipse of Egypt circa 3100 BC?
Is there some way to calculate when, if ever, one of these occurred over Egypt around about this period? Also, I understand that a total eclipse is relatively rare (recurring only 375 years or so according to this source) - does this value fluctuate depending on ones position on the globe? 70.112.97.77 (talk)


 * One important distinction is whether you mean a total solar eclipse at one particular point (which is rare) or anywhere on Earth (which is fairly common). That is, each eclipse is normally only a total eclipse for a small portion of the Earth (if anywhere at all), with the rest seeing either a partial eclipse or no eclipse at all (including the half of the Earth in night at the time). StuRat (talk) 03:00, 3 July 2013 (UTC)
 * here is NASA's list of total eclipses for 3999-3000BC, with lat and long coordinates. Cairo is near 30N, 30E. MChesterMC (talk) 08:20, 3 July 2013 (UTC)


 * Okay, so it looks like no total solar eclipses for that region around that time. Thanks for the help! 70.112.97.77 (talk) 18:35, 4 July 2013 (UTC)

NYC and nuclear attack
If, in the 1960s the Soviet Union decided to attack a city like New York with nuclear weapons, how long would humans have to wait before the city is safe enough to re-enter without threats of radiation poisoning? Thanks. 64.229.207.42 (talk) 03:06, 3 July 2013 (UTC)


 * It would depend on the bomb and how delivered . Hiroshima and Nagasaki are habitable now and have been for some time. μηδείς (talk) 03:18, 3 July 2013 (UTC)


 * The thing with radiation is that it doesn't just completely disappear some day. Instead it gradually reduces in magnitude.  So, when exactly it is "safe to return" is debatable.  Also, you said "radiation poisoning", which requires a fairly high level of radiation.  Lower levels continue to cause an increased incidence of cancer for years to follow. StuRat (talk) 03:19, 3 July 2013 (UTC)


 * Also, there tend to be "hot spots" remaining where the fallout dust and debris has collected for one reason or another - and those places remain more dangerously radioactive for longer. Other issues are that the primary radiation from the bomb can make other materials radioactive - and the half-lives of those materials is wildly variable.


 * As StuRat points out, radioactive decay isn't an all-or-nothing thing. If the particular radioactive isotope left behind by the explosion has a half-life of a year, then the radiation levels will halve every year from then on...but there is (essentially) never a day when there is no radioactivity left - and any amount of radiation increases your lifetime cancer risk.  After the Chernobyl reactor disaster, people halfway around the world and three decades later still have a small increased cancer risk because of it.  It's estimated that even 80 years after that explosion, your personal risk of getting thyroid cancer will be 0.3% higher than it otherwise would have been - solely because of that accident.
 * SteveBaker (talk) 20:38, 3 July 2013 (UTC)
 * Would depend largely on weather conditions as land contamination from a nuclear bomb would be caused mostly thru Nuclear fallout, not directly as most wrongly asume. --Kharon (talk) 21:02, 3 July 2013 (UTC)


 * There are a lot of variables. For one thing, if it was an attack in the 1960's then New York would have been out of range of soviet missiles. The bombs would have been delivered in the secondary attacks by aircraft. These would most likely have carried 'city busters'. To put it another way, very large hydrogen bombs of many megatons. The initiation hight of such bombs  (limited by high the delivery aircraft could fly)  would probable get graded as a 'ground burst'.  In other word, a third or more of the fire ball would make contact with the ground. In this scenario, a great deal of fall out is  produced -measuring many hundreds of rads. I don't have references to hand but your looking at two months before a short sojourn into the area could be safely  attempted (longer, if you are going by modern standards of allowable exposer rates)  . The Hiroshima and Nagasaki bombs were both air bursts. Therefore, after about an hour, the radiation had decayed enough, not to cause any short term hazard.  Those, that put their cancers down to entering  Hiroshima the day after are most likely grasping at straws. --Aspro (talk) 23:18, 3 July 2013 (UTC)


 * Are you sure that New York would have been out of range of Soviet missiles? What of those medium-range missiles in Cuba?  Or, for that matter, what of submarine-launched missiles? 24.23.196.85 (talk) 00:55, 4 July 2013 (UTC)
 * Indeed, Russian Submarines had the technology to do it according to our article: "the Soviet Union made its first successful underwater launch of a submarine ballistic missile in the White Sea on 10 September 1960", unless there is a claim that these misslies could not carry a nuclear warhead. So from that date on, New York was never out of range. --Lgriot (talk) 08:03, 4 July 2013 (UTC)


 * Those are fair questions. This is how I understood it at the time: During the 1960's, if war between the soviet union and the 'West' broke out, the major activity would have first taken place in Europe. Thus, one had American forces stationed in Germany with their atomic demolition W54's in order to destroy bridges from Russia in to to Europe.  There were atomic land-mines and other things as well in place. It was therefore in Europe, that the Soviet military advantage lay. Cuba only had  'very' short range nuclear missiles – not capable of reaching the US main land (the longer range missiles never arrived due to the blockade). The other Russian missiles were based in eastern Russia and could only target north western US states.  In those existing 1960 scenarios, there was no strategic advantage to the Soviets of nuking New York. Civilians can't hit back instantly, so  one concentrates on  their military forces that can. Therefore, all those now forgotten fall out shelters in NY were only created for political purposes (with a view that the Soviet missile range would improve over time). If secondary strikes became a strong possibility, then evacuation would have been a better option. So no. I don't see any earthy reason why NY should have expected a nuclear strike by missile. It was the way that WWIII was envisioned in those days.--Aspro (talk) 21:03, 4 July 2013 (UTC)


 * Actually, the SS-4 missiles deployed to Cuba had a maximum range of 1200 miles, which would have allowed them to reach as far as Richmond, VA, Corpus Christi, TX, and (barely) Washington DC. 24.23.196.85 (talk) 06:13, 5 July 2013 (UTC)
 * Actually. Deployment and Operational are two separate things. Wikipedia is not a good source but even-that quotes “We had to send a U-2 over to gain reconnaissance information on whether the Soviet missiles were becoming operational.” JFK would not have had the bargaining chips if they had been operational. So, Richmond, VA, Corpus Christi, TX, was safer from the Russian than their own gun owning citizens. This is an interest of mine because I wondered at the time why my parents and their friends were debating whether there was any point in planing a weekend away to go fishing (there is more to it than this but that is as far as I want to explain but whilst our American cousins suffered no more than a few Japanese explosive balloons during WWII we under went V2 bombardment blowing out window and bring down plaster ceilings, thus Cuba crisis   wasn't viewed as some kind of science fiction) So, NY would have been left to after strikes by city busters once SAC had been neutralized. It is the attempt to rewrite my history that I lived though  that I am objecting  to .--Aspro (talk) 18:12, 6 July 2013 (UTC)
 * Actually, Aspro, YOU are the one rewriting OUR history (that of "your American cousins" such as myself) by saying that we suffered "no more than a few Japanese explosive balloons during WWII" -- by writing such utter BS, you both disgrace the 3,000 of your American cousins who were horrifically killed in the Pearl Harbor attack, AND destroy both your own credibility and that of the Ref Desk! You should be ashamed of yourself for writing this, ignoramus! 24.23.196.85 (talk) 03:12, 7 July 2013 (UTC)
 * Lets just stick to the facts. The OP's question was about NY. The only inter-continental missiles the whole US experienced ever, were Japan’s balloons – period. The soviet missiles were aimed at the northwester US mainland and Europe. Even if they could have been sent  further, there was little point as they were too inaccurate over longer ranges. V2's  rained down on London because as Europe largest city it was so easy to hit somewhere (even so, counter intelligence soon had the falling too far to the south to disrupt the war effort significantly). Somewhere I have the formulae for how many missiles you need to launch in order to be sure that just one will hit the target. The bulk of those would have been concentrated on Europe. The US threat (as the Soviet Union saw it) was stationed  western Europe (or is that something you feel you  want to rewrite). It was the western boarders that Russia wanted to secure. The US inter continental missiles on the US  mainland were of no real concern to the Russians as  US Atlases and early Minute Men  could not hit a barn door either. What the general public was told  during those years, has in the fullness of time,  shown  to be a load of poppycock. --Aspro (talk) 15:01, 7 July 2013 (UTC)


 * The article on the Chernobyl disaster has quite a bit about the ongoing effects of radioactive contamination, including guesstimates of timescales for the area to become safe. Astronaut (talk) 18:34, 4 July 2013 (UTC)


 * I wonder if it is accurate to equate Chernobyl and a 1960's nuclear bomb? The Russian reactor had a large inventory of decay products from the nuclear fuel, in isotopes readily absorbed by the human body and isotopes with a very long half life, while a bomb might not. The goal of nuclear war planners was to fight and win a war, not to make the Earth an uninhabitable planet. Is it claimed that the Soviets would have gone out of their way to hit NYC with a "dirty bomb" encased in cobalt or whatever, or that 1960 nuclear strategy called for dirty ground bursts rather than high altitude bursts with a wider circle of destruction from blast and flash ignition? The ground burst claims run counter to US civil defense literature of the early 1960's which also predicted a short half-life for the fallout, so it would be safe to leave shelters after about 2 weeks. It was not expected that cities would be uninhabitable due to radiation for years or whatever. Edison (talk) 23:40, 4 July 2013 (UTC)

Bipolar Disorder associated features
Hi guys,

My post is related to bipolar disorder.

I am curious as to what features exist characteristic of bipolar disorder, particularly any features that are exclusive to the disorder. For instance, I am aware of ideas of reference as a feature of psychotic mania. Another example might be the connection between creativity and bipolar.

Are there any other major or minor examples of associated features (AF) of bipolar disorder that could be added to the current page on AF? (Second link)

Thanks! I have a personal interest in this as I am a 19 y/o male recently diagnosed with bipolar.

Jeremy

GRHooked (talk) 09:37, 3 July 2013 (UTC)


 * Have you looked at our article on hypomania? Looie496 (talk) 14:53, 3 July 2013 (UTC)


 * Remember that bipolar disorder is something of a spectrum, so you may want to check out spectrum disorder and Bipolar_spectrum. You may therefore have trouble finding things exclusive to the condition, except in extreme cases. IBE (talk) 03:48, 4 July 2013 (UTC)

Rehydration of troops in Iraq/ Afghanistan
Hi,

After having watched Jarhead, and also talking to troops that have served in Iraq/Afhanistan, it seems like good hydration is a massive part of serving there. Since a lot of the troops come from colder areas where less water is lost from sweat, this could cause a problem with troops not being used to drinking so much water so often, since they must sweat buckets under the "perfect storm" of hot weather, stress and heavy exercise. Did the US/ other countries have a way of preparing the troops before they went or while they were there to get troops used to drinking so much water (other than rehydration tablets). If so what did it entail? Obviously they just got them to drink a lot very often, but was there a particular regime they followed? 80.254.147.164 (talk) 11:47, 3 July 2013 (UTC)
 * You don't need training to know when you're thirsty and to take water then. Those drinks companies telling people they need to hydrate when they are not thirsty are a menace, drinking too much fluid is far more of a danger than mild dehydration. See water intoxication. Dmcq (talk) 12:28, 3 July 2013 (UTC)
 * Yes, I agree that for most it's pretty easy and unessecary to drink when not thirsty. But if you are in such a difficult environment where you are unsure when the next time you will be able to drink is, or when the next time that they will have to run for 3 miles in heavy gear will be, you might need a disciplined approach to keep yourself topped up, or at least repetition to get yourself in the habit. How much water does each soldier take on patrol? Or is water freely available enough that they can obtain bottles fairly easily? 80.254.147.164 (talk) 13:19, 3 July 2013 (UTC)
 * Three miles in kit? Human Mammal, Human Hunter - Attenborough is a clip showing a man run down and kill a kudu over eight hours during the heat of the day in the Kalahari desert. Persistence hunting is thought to be one of the first human adaptations. Dmcq (talk) 13:45, 3 July 2013 (UTC)
 * I saw that show - but the guy was nearly naked - and almost completely unencumbered with equipment. He wasn't dressed in battledress, bulletproof vest, with a helmet and a 100lb pack on his back.  Also, he had been adapted to the environment since birth rather than coming from someplace where the temperatures never get over 90F - and he was under much less stress because there weren't potentially snipers and IED's around every corner.  It's not a remotely comparable situation. SteveBaker (talk) 16:58, 3 July 2013 (UTC)


 * The following is OR but I have some confidence in it. I lived for 20 years in Tucson and did a lot of desert hiking in Afghanistan-like conditions, needing to drink literally gallons of water a day (actually Gatorade or even lukewarm ice-tea are better than plain water, but whatever).  My experience is that the ability of the body to process that much water develops over time.  Early in the hot season I would find it difficult to drink as much as I needed (there's a sort of sick feeling), but after a few hikes I could handle a lot more.  I also did many hikes with visitors from colder places, and found that they had a lot more difficulty handling the heat than I did. Looie496 (talk) 17:12, 3 July 2013 (UTC)
 * You probably were able to sweat properly. The problem with wearing an army uniform with bulletproof vest etc is not being able to sweat properly. I believe they try and use materials that wick the sweat away but heat stroke is a real possibility if they can't keep their temperature down. A place with high humidity now, they can be quite unpleasant, you just lie there waiting for it to get cooler. Dmcq (talk) 18:12, 3 July 2013 (UTC)
 * Something especially nasty happens when the air temperatures get above body temperature (we had three 106 degF days here in Texas last week - so I speak with some authority!) Normally, when the temperatures are more sane, your body creates a volume of warm air around it - an effect which clothing accentuates by trapping that air.  Removing clothing and having a nice breeze helps that warm air to be moved away from you - so you feel cooler.  That's why fans work - they don't cool the air - they just let you feel the true ambient temperature.  However, when the ambient temperature gets above body temp, all of this goes horribly wrong - because you're replacing body temperature air with hotter air - and that makes matters worse.  A "cool breeze" becomes more like opening an oven door!
 * Moving air around still helps a little bit though because the only way you can lose heat under those circumstances is by sweating and letting the evaporating water carry the heat away. But if you gradually build up a layer of humid air around your skin, that slows down the evaporation rate - so a gentle breeze still helps to some degree by reducing the humidity close to your skin.  The idea behind wearing seemingly warm clothing in hot weather is to prevent that higher-than-body-temperature air from reaching you - but it needs to be made so as to allow sweat to wick away and evaporate on the outside of the clothing in order to avoid humidity build-up.  This ends up being a tricky business.
 * If humidity is close to 100% and temperatures are over body heat, then you have a really dangerous situation. Sweat doesn't evaporate because of the 100% humidity - and breezes only make you hotter - so there is really nothing to keep your body temperature reasonable.  At that point, the only thing you can reasonably do is to keep heat-generating activities to a minimum and hope that the temperature drops before you die from it.
 * SteveBaker (talk) 20:20, 3 July 2013 (UTC)
 * There are sources to be found about this. I searched "soldiers afghanistan hydration rules" and came up with  on the first page.  This really isn't my field, and some of the considerations involved in deciding on these protocols are likely not obvious. Wnt (talk) 22:11, 3 July 2013 (UTC)

Surely it's worth remembering now, as the leaders of the countries involved recently seemed to forget, that people from cold places have tried to invade these places many times before, going back at least a hundred and fifty years, and probably much longer. Britain and Russia come to mind. Their soldiers would not have had access to modern re-hydrating drinks, nor almost certainly to the mere quantities of fluids available to participants today. I don't know how they coped, but I often wonder about it. HiLo48 (talk) 22:20, 3 July 2013 (UTC)
 * We're the same species and most people have little difficulty in acclimatizing to hot weather and humans evolved in such conditions long before the idea of re-hydrating drinks was oversold. Dmcq (talk) 23:47, 3 July 2013 (UTC)
 * Yes, but as I already explained, these people are running around in bullet proof vests, combat fatigues, helmets and 100lb packs...we evolved for exercising in not much more than a spear and a loincloth. This kind of abuse of the body requires special intervention. SteveBaker (talk) 03:10, 4 July 2013 (UTC)
 * I was answering HiLo48's question just above. The document that Wnt just above that again pointed at gives the answer about the soldiers nowadays. They have good answers in that though they still seem to talk more in terms of dehydration rather than heat stress. They still buy into what the drinks companies say to some extent though they have cut down on the recommended water because of the casualties from water intoxication. Dmcq (talk) 08:24, 4 July 2013 (UTC)
 * Not every soldier has a 100lb pack on its back. And even when they are supposed to carry one to their place of deployment, they don't go on patrol like that. Many soldiers also come from a pretty hot weather region, and could be stationed in hot places like Kuwait or Saudi Arabia before Iraq. Besides that Afghanistan is not that hot. Many regions in the US are hotter. OsmanRF34 (talk) 00:59, 5 July 2013 (UTC)

I think some of the answers above border on medical advice. I worked in the Australian desert for years, and we were constantly counselled by our employer to drink water until our urine was a pale straw colour. There were posters next to the urinals with various colours showing us to drink more if we were anything less than the palest straw shown. The posters also had sayings like "By the time you feel thirsty, you're already dehydrated". 202.155.85.18 (talk) 05:36, 5 July 2013 (UTC)
 * Actually, I found the exact images, and . 202.155.85.18 (talk) 05:41, 5 July 2013 (UTC)
 * Perhaps you should send the american army recommendations above to your employer. Dmcq (talk) 13:19, 5 July 2013 (UTC)
 * Those charts seem a little hard to interpret, in part because they seem to be different colors, and mostly because it's not specified where you're supposed to be looking at the urine - in midair (where it depends on flow rate, which depends on how dehydrated you are!) in a vessel of what depth, etc.? Also of course because urine varies in color depending on diet. Wnt (talk) 15:24, 5 July 2013 (UTC)


 * I should also note that water intoxication cited above says that it is actually a very rare condition. I would be curious, though, whether water is "addictive"?  In general heat acclimatization actually increases water requirements  but does prolonged restriction of water induce, say, higher levels of some transporter proteins in the kidneys?  To be clear, water rationing is discredited in the military sense  - but I'm not sure if that's because modern militaries assume the ability to transport large amounts of water and are more worried about other ways of getting killed due to poor performance rather than running out of water. Wnt (talk) 15:32, 5 July 2013 (UTC)


 * To address HiLo's query about how previous generations of soldiers coped with conditions in Afghanistan, it should be remembered that the British had had a century of experience of operating in India before venturing there. The troops used in the Second Afghan War were those stationed in India and were thus fully acclimatised beforehand, tours of duty being seven years if I recall correctly. British officers employed tactics on the march such as enforced rest periods during the hottest part of the day, and must have been aware of how hard they could push their men, through hard experience. However, when these precautions were set aside in Lord Roberts' famous forced march to the Battle of Kandahar in 1880 (300 miles in 3 weeks): "The pace of the march was taking its toll with soldiers falling sick at the rate of 500 a day".  Alansplodge (talk) 17:08, 5 July 2013 (UTC)
 * The standard speed for a "forced march" at that time was 20 miles per day. 300 miles in 21 days is 15 miles per day - so they had given the men a significant reduction - despite the extreme urgency.  Also, consider that at the end of that march, the men managed a significant victory - so it should be said that the pace of the march was actually about right in terms of the overall course of the war - better to lose some men to heat exhaustion along the way than to fail to relieve the garrison by arriving too late and take much heavier casualties overall.  It was a tough call - and Roberts got it about right. SteveBaker (talk) 21:06, 5 July 2013 (UTC)