Wikipedia:Reference desk/Archives/Science/2014 December 27
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December 27
[edit]Reducing the fever by drugs doesn't harm the body?
[edit]In general, When people have a fever, it indicates that they have an inflammation of pathogenic microbes. That the natural way of the body to kill them. My question is When people take drugs that reduces the fever, doesn't it disturb the body to make its work and to kill the pathogenic microbes? 213.57.97.151 (talk) 05:52, 27 December 2014 (UTC)
- I believe the fever to be a side effect of a massive cellular level war between the body's immune system and the infection, and a high enough fever will start to damage organs, so keeping body temperature low is important. StuRat (talk) 06:43, 27 December 2014 (UTC)
- Do you think that any fever can damage the organs? there are many levels of fever. 213.57.97.151 (talk) 07:32, 27 December 2014 (UTC)
- No, not any fever, a "a high enough fever", as I said. StuRat (talk) 20:27, 27 December 2014 (UTC)
- I am no doctor and have no idea about medicine, but once I asked the very same question and what I gathered from the answers is that (in my (uninformed) opinion) we still do a lot of things in medicine without really having a solid understanding of what's going on. --Schweinchen (talk) 09:37, 27 December 2014 (UTC)
- Since no-one has linked to it, yet, I'll just mention that we do have an article on Fever that mentions differing views, and that damage doesn't occur below 107 degrees F. Dbfirs 09:53, 27 December 2014 (UTC)
- I didn't see any reference for the my question in our article fever.213.57.97.151 (talk) 12:41, 27 December 2014 (UTC)
- There are some referenced studies in the section Fever#Usefulness. Dbfirs 13:33, 27 December 2014 (UTC)
- The problem with high fevers is that they denature the bodies proteins, causing brain damage first and then general organ failure. This should all be in the fever article. μηδείς (talk) 18:45, 27 December 2014 (UTC)
- I would say there is a general problem with meds designed to get you "back to work quickly" by masking symptoms, when you probably should be home recuperating and not at work infecting others. Fever is just one of the symptoms. StuRat (talk) 20:29, 27 December 2014 (UTC)
Self driving trains
[edit]Why don't all trains just become self driving? The technology is there so is it just cost? — Preceding unsigned comment added by 94.14.212.193 (talk) 14:00, 27 December 2014 (UTC)
- In some cases it's a matter of influential train-driver unions, in others, the public perception of safety. Many operators of self-driving trains prefer to have a competent human on board to deal with breakdowns and emergencies, even when he or she is not actually "driving". Dbfirs 14:38, 27 December 2014 (UTC)
- I spent a small slice of my career designing simulators too teach train drivers' their job - and I went into it thinking "Just how hard can this be? After all, it's not like a car where you have to steer - or even decide where to go - it's just a throttle and a brake!" So I set about learning what it takes to drive a train - and I came out of it realizing that this can be an incredibly difficult job. In the USA, train drivers get paid more than airline pilots - and that's not because they have a better union. There is an immense amount of subtlety to driving a 2 mile long coal train with seven locomotives in mountainous terrain with poor traction and tight winding curves in some areas - they are also responsible for checking and reporting on track defects, broken signals, missing signs...you name it. It's also a very stressful job. I came out of the learning curve with great respect for the difficulty of driving a train. It's interesting to note that the reasons that Burlington-Northern wanted us to build them simulators was not so much to teach people to drive trains - but to train them to minimize fuel usage, which is a huge deal for the company. I forget the exact numbers - but the difference in fuel cost between their best driver and an average driver by far exceeded the salary they paid a train driver - so getting good people was absolutely paramount to their operations.
- The easiest type of vehicle to automate is an aircraft (so it's no surprise that we have wildly successful drones out there) - and we know that the biggest problem with airline pilots is surviving the boredom and inactivity because the plane pretty much flies itself already. Since I've also spent years working on flight simulators - I can definitely say that flying a modern airliner is a hell of a lot easier than driving a freight train. That's surprising because aircraft have an insane number of controls, and a vast number of instruments to monitor - where a train has very few of either.
- I doubt that the public would have much of a problem with robotic freight trains - but I suspect that the big issues (as with driverless cars) would come when they'd have to give up the feeling of security that comes from having a person at the controls of a passenger train...despite the fact that human error dwarfs all other causes of accidents - in the air on tarmac or on rails.
- With the ongoing fear of cyberwar with North Korea, I would emphatically not want to trust a robot freight train loaded with dangerous cargo. For that matter, I wouldn't feel all that safe about some junior railman who believes every speed limit the computer has listed for the track. (And I suppose the hackers can figure out which ones are junior easily enough...) Wnt (talk) 17:19, 27 December 2014 (UTC)
- Public perception of safety is obviously an issue. However this will also depend on local issues and other factors. Let's not forget as the OP said and shown by Dbfirs link, driverless trains are a reality and have been for a relatively long time now with many millions transported every day. I rode on one circa 1999-2001, and IIRC this didn't have any staff on the train or many platforms (was monitored by CCTV). OTOH, AFAIK and our article also suggests these are nearly universally urban lines metro/rapid transit sort of thing generally with dedicated lines with right of way, no mountainous terrain or difficult curves, electric locomotives, communication systems and stuff set up for the purpose, etc. Long distance self driving trains don't seem common if they even exist in commercial operation. [1] actually claims the Rio Tinto line in Australia (mentioned in our article) will be the "first automated, long distance, heavy haul rail network", although that still allows a long distance non heavy haul network and I'm not sure the length of the line and think it's also dedicated. (One advantage to driverless trains in urban systems which is less prominent in long distances systems is allowing all day high frequency operation without having an extremely high cost.) Nil Einne (talk) 17:45, 27 December 2014 (UTC)
- I'd think the safest train would combine the best of a human operator, like flexibility, with the best of a computer, like consistency. For example, you could have a human operator, but one who must pass a breathalyzer test to turn on the engine, and who gets alarms if the computer detects any problems, including the operator's head dropping. Those alarms should also be reported back to the control center, so they know, for example, if one of their engineers needs a nap. StuRat (talk) 19:11, 27 December 2014 (UTC)
The visible "envelope" of atmosphere slightly beneath the aurora
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/63/Aurora_Borealis.jpg/220px-Aurora_Borealis.jpg)
I just saw a link to some really neat time lapse photography of auroras and other phenomena (though, alas, I see no indication of the time compression scale). [2] But I find myself focusing in on one single detail, namely, that the Earth seems surrounded by a sharply defined, well, what looks like a "cell membrane" - a visible 'top of the atmosphere' (though it isn't) which appears in the video at 0:55 and 1:07, for example. In the latter shot you can see it fade to a sharp rainbow line; in true darkness it is not visible and in bright light it is apparently swamped out, but at 5:25 it is lit with the glow of city lights. Now what's interesting at 1:07 and in the other aurora shots is that you can see it is separated by what looks like (on the computer screen!) a small gap from the base of the aurora. When I look at atmosphere of Earth it seems like auroras can be at a wide range of heights, yet with this gap there is a sense of a consistent organization. Which makes me wonder...
- Is the "membrane" I'm seeing actually at a definable height, as opposed to receding if the spaceship went lower like a rainbow might?
- Is the "membrane" always at the same height, or at one which can be predicted from simple parameters like time of day?
- And if so... where is it?
- And is the distance from it to the bottom of the aurora genuinely pretty constant?
- And, of course... what layer of the atmosphere is it?
- And is it produced by refraction or by ice crystals or ...?
Wnt (talk) 17:12, 27 December 2014 (UTC)
- I'm not an expert in this field, but I would say that the boundary visible in the video is the tropopause. See, for example, File:Moon Limb & Troposphere.JPG, which shows the layers distinctly. It's visibile because it's an inversion layer - dust and other particles reach the top of the inversion, and are not carried any higher by convection currents. Tevildo (talk) 10:32, 29 December 2014 (UTC)
How detailed must a perfectly accurate brain model be?
[edit]Let's say we want to create a synthetic brain based on a real brain. To what level of detail would we need to model for the synthetic brain to behave indistinguishably from the real brain? Would we need to go down to the level of chemistry? Or even further than that, to subatomic particles where the uncertainty principle governs everything?--31.200.175.242 (talk) 17:43, 27 December 2014 (UTC)
- Honestly I don't think anyone can answer this with confidence. Without even getting into "qualia", simply understanding basics of memory like long-term potentiation remains at a very primitive level of experimentation. It is one thing to replace the brain with a device, something else again to define when it is indistinguishable. Wnt (talk) 18:02, 27 December 2014 (UTC)
- Neurons function using neurotransmitters and action potentials. The physical properties of the cells depend on the chemical structure of the fat, protein and other molecules and ions that make them up. Their behavior is electrochemical. As far as we know two brains that were identical at the molecular and chemical level down to charge distributions would be identical. There are some fanciful and rather materialistically naive theories of consciousness which treat it as a substance (e.g., eliminative materialism); and speculation based on fallacies, such as Penrose's The Emperor's New Mind that argue consciousness is weird and quantum mechanics is weird so the two must be intertwined. But there's no evidence of that beyond the fact that we know quantum mechanics is involved in the chemistry as such. There's no guarantee that two brains that were electrochemically identical (and in bodies) would both have the exact same conscious state, especially over time, but they would both be workable brains. μηδείς (talk) 18:38, 27 December 2014 (UTC)
- (I have no relationship with OP.) This is a very high-quality response, Medeis, and I'm glad you made it, I appreciate it and was glad to read it.212.96.61.236 (talk) 22:23, 27 December 2014 (UTC)
- I would have sent you a "thank" electronically, but evidently IP's can't get "thank"s so, I do so here in text. μηδείς (talk) 01:03, 28 December 2014 (UTC)
- For that matter, though we quickly get into some truly theoretical and abstruse territory going down this path, it's entirely within the realm of possibility that two neural networks could give rise to identical states of consciousness even if they were constructed from radical different materials -- provided that the associations and responsive thresholds between all of the nodes (neurons) were identical. Many experts on theory of mind (both cognitive scientists and philosophers) have used this as a lens to try to deconstruct consciousness and the nature of reality as a mental construct through thought experiments exploring (for example) whether a completely digital simulation that replicated the firing of each and every neuron in a brain would in fact be the exact same entity as that which arose from the model brain itself. Basically an adaptation of the old brain in a vat argument that asks what would be the implications if it were not just the sensory stimuli that were simulated, but indeed the very physical processes of the brain itself.
- Of course, it's worth dusting off that old chestnut that the brain has more individual associations between its neurons than there are atoms in the observable universe; when you view this question in that light, it's clear that the complexity of the task of actually creating an absolutely perfect replica brain are truly astronomical in scale and that it's very much a possibility that such a feat is simply outside the bounds of feasibility -- and possibly not just at present time, but indeed ever (it has been argued). Still, even as purely abstract inquiries that may never prove empirically verifiable, these thought experiments do provide us with some compelling (if sometimes seemingly counter-intuitive) insights into the interplay between concepts of consciousness and reality -- two manner of phenomena that to this day leave us largely just as perplexed as the classical philosophers, when it comes to establishing stable definitions. Anyway, getting back to the original point, with regard to the computational model of the mind, it's entirely possible (likely even) that the material medium is only relevant insofar as its physical properties shape the pattern of associations between the nodes which make up the neural net.
- On a side note, while I absolutely agree with you that quantum phenomena have very little influence on the gross associations and patterns of a neural network like the human brain (and that such associations tend to be forwarded by those with little understanding of the levels of physical hierarchy involved), it should be noted that this lack of relevance may not necessarily and inevitably be the case for every kind of consciousness. Consider the implications of quantum computing -- bearing in mind the kinds of problems it is likely to be most useful in addressing, and how it would tackle them -- and it quickly becomes clear that we can't even begin to fathom the implications for consciousness as superpositions become a part of computational methods. Snow talk 08:21, 28 December 2014 (UTC)
- It's kind of a tricky question. Lots of what goes on in the brain is undoubtedly noise, and once we have a thorough functional understanding of how the brain works — if that ever happens — we will probably be able to create radically simplified models that are more or less indistinguishable from it. The problem is that we currently have nothing approaching that level of understanding. In our current situation, the only way we could create a model indistinguishable from the brain would be to replicate it down to the level of individual molecules — not all molecules, but at least large molecules such as chemical receptors. Some people think it would be necessary to go down to the quantum level, but they are mainly physicists, and most neuroscientists don't buy their arguments. Looie496 (talk) 19:44, 27 December 2014 (UTC)
- Yeah, that's crazy talk. Worrying about quantum entanglement and subnuclear particles and so forth is doing the X is spooky and Y is spooky so X and Y must be the same fallacy again. Consciousness obviously rises at an emergent level above the cellular level. Most current theories of the unity of consciousness have to deal with the timing of firing of cells. To simplify, if your red, round, fruity, crisp, mouth muscle, and so forth cells are all firing in harmony you will have the perception "I am eating an apple." See Hofstadter's I Am a Strange Loop and many other works. But quarks and such matter to consciousness in the same way the color you paint your house helps it deal with tornadoes. Since no phenomenon we know of or even suspect to exist has to do with nuclear decay we can safely ignore various aspects of nuclear physics and concentrate on biochemistry and higher levels of organization. μηδείς (talk) 22:53, 27 December 2014 (UTC)
- What happens if you were absolutely balanced while deciding something without smooth gradation. And you must choose one. Would quantum noise decide for you? Sagittarian Milky Way (talk) 00:12, 28 December 2014 (UTC)
- See Buridan's ass. I would say something like that has to be the case, although we're not going to have any empirical evidence to back it up given ethical and technological constraints. It's the reason why I said in my first post that an electrochemically identical brain (in a functional body) would be a working brain, but would not necessarily have the same conscious experience over time. In fact, chaos theory and common sense insist the two brains would rapidly diverge as experience accumulated. See this very recent article on real-time scanning and manipulation of brain cells. μηδείς (talk) 00:59, 28 December 2014 (UTC)
- What happens if you were absolutely balanced while deciding something without smooth gradation. And you must choose one. Would quantum noise decide for you? Sagittarian Milky Way (talk) 00:12, 28 December 2014 (UTC)
- Yeah, that's crazy talk. Worrying about quantum entanglement and subnuclear particles and so forth is doing the X is spooky and Y is spooky so X and Y must be the same fallacy again. Consciousness obviously rises at an emergent level above the cellular level. Most current theories of the unity of consciousness have to deal with the timing of firing of cells. To simplify, if your red, round, fruity, crisp, mouth muscle, and so forth cells are all firing in harmony you will have the perception "I am eating an apple." See Hofstadter's I Am a Strange Loop and many other works. But quarks and such matter to consciousness in the same way the color you paint your house helps it deal with tornadoes. Since no phenomenon we know of or even suspect to exist has to do with nuclear decay we can safely ignore various aspects of nuclear physics and concentrate on biochemistry and higher levels of organization. μηδείς (talk) 22:53, 27 December 2014 (UTC)
Tiles instead of continuous cover on Space Shuttles
[edit]Why Space Shuttles used tiles instead of continuous cover as heat insulation, which can't detach the way tiles could? Brandmeistertalk 19:51, 27 December 2014 (UTC)
- I think the very fact that they could detach was desirable, so that tiles damaged during re-entry could easily be replaced. StuRat (talk) 20:11, 27 December 2014 (UTC)
- This is an interesting question, and in fact our article Space Shuttle thermal protection system doesn't presently give the answer. What is clear enough is that many are made of LI-900, a material which is said [3] to be a sponge of silicon dioxide in 94% air, and which by all accounts is fragile - fragile enough to break by hand. There would seem therefore to be a major technical issue in trying to keep a single continuous layer, and if they have to have seams, why not break them at a preset pre-tested position, i.e. a tile boundary? But I haven't looked into this properly. Wnt (talk) 23:43, 27 December 2014 (UTC)
- A continuous skin wouldn't allow for expansion and aerodynamic deflections of the structure in the way that tiles do - see the 'HIGH-TEMPERATURE REUSABLE SURFACE INSULATION TILES' section here: [4] AndyTheGrump (talk) 23:52, 27 December 2014 (UTC)
- It is worth noting here (just in case anyone reading this gets the wrong impression) that detaching tiles had nothing to do with the 2003 Space Shuttle Columbia disaster, which was instead caused by foam insulation shed from the external tank,striking the leading edge of the port wing. -- ToE 00:21, 28 December 2014 (UTC)
Cheeky/irreverent precious substance questions
[edit]If you dropped a perfect US handball-sized sphere of flawless diamond how would it bounce? (American handballs are only a bit over golf-sized, foreign ones are huge) What about other combinations of sizes 1 carat to Cullinan, surfaces, shapes, and drop heights? Same thing with gold. I'm guessing it has a dead cat bounce cause it's so soft but what about 14 karat or Sterling or pure silver or platinum or ruby, emerald, or pearls?
Two last questions. You can mark 24 karat gold without hurting your teeth - what substance could I chew to know how vigorously I could chew gold without it hurting? If the guinea nailed to the wood in Mutiny on the Bounty was real then gold is basically like yellow silly putty had children with steel. What do precious/noble metals and common jewelry alloys taste like? (Just licking them, no swallowing obviously). Maybe I should've licked my inherited gold while I still had it.. Sagittarian Milky Way (talk) 20:01, 27 December 2014 (UTC)
- Suggest you lay off the egg nog for a while. Short Brigade Harvester Boris (talk) 20:06, 27 December 2014 (UTC)
- To determine how well something will bounce, you need to list the surface it's dropped onto. For a very hard object, I'd expect very little bounce, unless dropped on an equally hard surface, like two billiard balls hitting each other.
- And metals taste, well, metallic, although you are tasting the tarnish on them rather than the elemental metal. I'd expect gold and platinum to have very littler taste, since they don't tarnish. StuRat (talk) 20:09, 27 December 2014 (UTC)
- I too thought that gold/Pt would either taste metallic if it had anything at all but didn't know if there were different flavors (like "taste copper not aluminum if you want to know what pure silver tastes like but don't have any"). Sagittarian Milky Way (talk) 20:28, 27 December 2014 (UTC)
- Would any of linoleum, stone, ceramic, wood, metal, concrete or cement flooring, ice or common paving materials cause a bounce visible to the naked eye? I guess you could shoot small diamonds out of an airgun if the bigger ones would break at heights needed for bouncing but the small ones reach terminal velocity without breaking on impact. This is now one of the things I would do if I were a billionaire and no one knew the answer. Sagittarian Milky Way (talk) 20:54, 27 December 2014 (UTC)
- Gold and silver are perfectly edible and used in Indian cuisine. --TammyMoet (talk) 22:04, 27 December 2014 (UTC)
- Well harmless or not I'm not keen on swallowing metals. Sagittarian Milky Way (talk) 23:58, 27 December 2014 (UTC)
- Swallowing metal is essential to life. AndyTheGrump (talk) 00:03, 28 December 2014 (UTC)
- I don't know much about materials science, but come on, somebody has to actually try here. Elasticity (physics) is determined by things like Young's modulus and shear modulus, which for diamond are 1220 GPa[5] and 553 GPa[6] respectively. A pity I don't really understand whether that means the diamond starts to shear rather than deform when thrown at a wall. There is a paper on the elasticity of diamond at [7] which may also be helpful. Wnt (talk) 14:16, 28 December 2014 (UTC)
Reception of Einstein's ideas
[edit]Your typical internet crackpot will often claim that it doesn't matter whether people ridicule him. Einstein was also considered a joke, until he proved that he was right. And so goes the defense of an internet ground-breaking physics theory. But is it right at all that Einstein met lots of jest and disdain before he could prove them all wrong?--Noopolo (talk) 20:08, 27 December 2014 (UTC)
- Probably the ones who thought he was nuts were ordinary people, with physicists taking him more seriously. There are a lot of things that can't be explained by Newtonian physics, and any physicist then would have been aware of this. StuRat (talk) 20:15, 27 December 2014 (UTC)
- Not really - see Criticism of the theory of relativity. His ideas were disputed certainly, but not ridiculed by his scientific peers. AndyTheGrump (talk) 20:17, 27 December 2014 (UTC)
- Special relativity was published in 1905, and the following year eminent physicist Max Planck gave a lecture promoting it. At that point there was no more proof of relativity than in the original paper, but the theory was considered very appealing by many at the time. The annus mirabilis papers, which were probably Einstein's first really ground breaking works, were all discussed in the physics community essentially immediately upon publication. Now, by no means did everyone agree. Luminiferous aether and other theories had serious supporters for many years after relativity was published, but Einstein's theories were undoubtedly taken seriously even by those who thought they were wrong. Dragons flight (talk) 20:36, 27 December 2014 (UTC)
When told of a book entitled "One Hundred Authors against Einstein", he replied "Why one hundred? If I were wrong, one would have been enough.". Greglocock (talk) 02:36, 28 December 2014 (UTC)
- As I understand it, physics was a declining field of study as Newtonian and Maxwell had summed it up quite nicely except for a few loose ends. Einstein went after quantum effects first by earninf the Nobel prize for the photoelectric effect. He then moved toward relativity as quantum stuff made him a bit uneasy. Both are now cornerstone basis of modern physics. --DHeyward (talk) 09:24, 28 December 2014 (UTC)
- We mustn't forget his paper on Brownian motion, which essentially proved the reality of atoms, something that was widely disputed at the time. Also the idea that physics was nearly complete was by no means universal. Those "loose ends" included the discovery by Becquerel, Thompson, and the Curies of radioactivity, which the physics of the time could not even begin to explain. This was a loose end of greater magnitude than the current problems with dark matter and dark energy. Looie496 (talk) 15:08, 28 December 2014 (UTC)
- The 1933 pamphlet, Hundert Autoren gegen Einstein, is discussed at Criticism of the theory of relativity#A Hundred Authors Against Einstein, and I found images of the text (in the original German) here. Is the English translation available online? -- ToE 13:51, 29 December 2014 (UTC)
Why was any rocket ever painted?
[edit]Paint is heavy by rocket standards and just decoration. Sagittarian Milky Way (talk) 20:16, 27 December 2014 (UTC)
- If paint was 'just decoration', you might be right. However, it also protects against corrosion for a start. The large Saturn V rockets were mostly white (probably to minimise heating due to sunlight), with contrasting black areas possibly to assist tracking. [8] AndyTheGrump (talk) 20:22, 27 December 2014 (UTC)
- Well the orange Space Shuttle tank was painted white once but then was left bare cause it was a waste of lifting power. Weren't the Mercury rockets shiny metal? That addresses the issues you mentioned. Sagittarian Milky Way (talk) 21:03, 27 December 2014 (UTC)
- 'Shiny metal' (specifically the aluminium alloys most likely used) tends to corrode fairly quickly in coastal environments like Cape Kennedy, due to salt spray. AndyTheGrump (talk) 21:08, 27 December 2014 (UTC)
- Oh, I didn't know that aluminum corroded on salt (I don't cook), I would've guessed it'd form a transparently thin layer of aluminum rust just like the shiny side of inland aluminum foil. Sagittarian Milky Way (talk) 21:21, 27 December 2014 (UTC)
- 'Shiny metal' (specifically the aluminium alloys most likely used) tends to corrode fairly quickly in coastal environments like Cape Kennedy, due to salt spray. AndyTheGrump (talk) 21:08, 27 December 2014 (UTC)
- Well the orange Space Shuttle tank was painted white once but then was left bare cause it was a waste of lifting power. Weren't the Mercury rockets shiny metal? That addresses the issues you mentioned. Sagittarian Milky Way (talk) 21:03, 27 December 2014 (UTC)
- If the rocket crashed, it might be useful to identify portions, especially if found years later, if it had a distinctive markings. StuRat (talk) 20:26, 27 December 2014 (UTC)
- Well they could use shiny metal and paint just the markings, or even just anodize and roughen the metal to make markings. If that wasn't dark enough (I'm not familiar with ways to darken metal), a translucently thin paint coating could've been added to them. Sagittarian Milky Way (talk) 21:16, 27 December 2014 (UTC)
- Zinc or strontium chromate-containing paints are commonly used to protect the metal surface ...-Dieter K. Huzel; David H. Huang (1992). Modern Engineering for Design of Liquid-Propellant Rocket Engines. AIAA. pp. 403–. ISBN 978-1-60086-400-1. -- Moxy (talk) 21:31, 27 December 2014 (UTC)
![](http://upload.wikimedia.org/wikipedia/commons/thumb/d/de/V-2_Rocket_On_Meillerwagen.jpg/220px-V-2_Rocket_On_Meillerwagen.jpg)
- The V-2 rocket, the forefather of all modern space rockets, was painted with a large black and white check pattern "...to observe any variation or roll of the rocket. The exact pattern was changed many times, and as with the rest of the rocket, the pattern was examined and altered if warranted". [9] Alansplodge (talk) 22:19, 27 December 2014 (UTC)
Hand pain
[edit]I had cut the palm of my hand, it is now fully healed with no pain (and hence I'm not asking for medical advice). However, after it appeared to be fully healed, I still had the occasional sharp pain for a while. That's now ended, too, but I wonder why I continued to feel pain after the wound appeared to be fully healed. Were there nerve endings that still needed to heal at that time ? StuRat (talk) 20:23, 27 December 2014 (UTC)
- This is fairly common. I had a cut in the heel of my hand almost 40 years ago and it still hurts occasionally. It was a deep cut and I assume it did damage to nerves or muscle. Short Brigade Harvester Boris (talk) 21:09, 27 December 2014 (UTC)
You probably have knife cancer, Stu. See a doctor. They do take x-rays to see if you've left a metal fragment or a chipped bone behind after the skin heals. . μηδείς (talk) 22:28, 27 December 2014(UTC
- Have a look at this online gross anatomical drawing of the palm [10] Do you think your injury may have damage any connective tissue according to those drawing? See fascia. If so, your epidermis (the part of your palm that you can see) may have healed but there may have been scared tissue still present in the fascia – which is slower to heal. Read this quick, as although you state you are not asking for medical advice, there appears to be an acute outbreak on the Ref Desks of manic hatting.--Aspro (talk) 22:47, 27 December 2014 (UTC)
- No one here is qualified to answer your question. If you're concerned, see a doctor. ←Baseball Bugs What's up, Doc? carrots→ 22:56, 27 December 2014 (UTC)
Rabbit inbreeding and genetic diseases
[edit]Do rabbits get many genetic diseases from all the in-family inbreeding? Gil_mo (talk) 21:37, 27 December 2014 (UTC)
- undoubtedly they can, just on principle, but two factors mitigate against it mattering, they have many kits, and those with double recessive lethal genes simply won't develop or die at birth and so on. Second, many genetic diseases don't show up until adulthood or senescence, and most rabbits don't make it that far--that's why they need to breed like rabbits. See google on genetic diesase domesticated rabbit. μηδείς (talk) 22:35, 27 December 2014 (UTC)
- Yea, inbreeding could lead to traits like buck teeth, a constantly twitching nose, and extremely long ears. :-) StuRat (talk) 01:11, 28 December 2014 (UTC)
- Are you asking about domestic rabbits that are deliberately inbred by humans, or wild populations? If you haven't already done so, you should read our article inbreeding. In the wild there should be enough unrelated rabbits available so the some inbreeding is not really a problem for the overall population. Any system used by humans to produce inbred animals employs selective inbreeeding. Any animals with obvious defects are are weeded out and only the best quality ones are used for breeding stock. Of course, this is not completely effective as some defects can't be seen, and then inbreeding depression can become a problem. There are also other defects that can become apparent in groups of animals with a limited genetic pool, such as hip displasia and epilepsy in pedigree dogs. There is an interesting discussion about inbreeding in humans here, the principles of which also apply to animals. Richerman (talk) 11:40, 28 December 2014 (UTC)