Wikipedia:Reference desk/Archives/Science/2009 June 26

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June 26

Homeopathic Medicine vs Allopathic Medicine

Basically, I'm asking this question here. Since I saw signs for Homeopathic Allergy at one of the local Whole Foods in my area, a few mos back. Now, I'm wondering if theres any real difference between this vs other.--Jessica A Bruno 22:12, 28 June 2009 (UTC) —Preceding unsigned comment added by Jessicaabruno (talk • contribs) 20:04, 25 June 2009

Homeopathy is pseudoscientific nonsense. See also Homeopathy and allopathy. Friday (talk) 00:06, 26 June 2009 (UTC)

Note that from about 1790 (Benjamin Rush) until perhaps 1910 (the last of these quacks), allopaths or "real doctors" would invariably bleed a patient by removing a dangerous amount of blood, and purge the patient by giving a poison called calomel, which was a mercury compound. These allopaths killed thousands of US citizens, including several presidents, as surely as if they had been assassins and vampires. Their medical practice was not empirically based on experimentation, but was rather based on conjecture and superstition. A witch doctor who rattled a gourd would have produced better outcomes than these bleeding and purging quacks. Edison (talk) 05:32, 26 June 2009 (UTC)

Note also that there were no practitioners called "allopaths" until Samuel Hahnemann made up the term to categorize his foes. It simply means "non-homeopath", and no set of practitioners have ever practiced medicine based upon the principles that Hahnemann claimed they did. Those who use the term "allopathic" today (and sadly some do, even though it is fundamentally misrepresentative) do so in order to disparage their foes; a more honest term would be "practitioners of evidence-based medicine". - Nunh-huh 08:20, 26 June 2009 (UTC)

I have to say that "normal" medicine has only recently embraced the concept of "evidence-based" medicine, and that this is turning certain drugs and practices from being the "first choice" to "unproven". See for example [1]. --TammyMoet (talk) 13:13, 26 June 2009 (UTC)

Well, if by "recent" you mean "in the last hundred years", then yes. --Tango (talk) 13:37, 26 June 2009 (UTC)

Neither of the terms "homeopathic" or "allopathic" are particularly meaningful. The "allo-" prefix means "different" or "strange" - it's not really a good term for "conventional" or "evidence-based" medicine. The "homeo-" prefix means "similar" or "uniform" - which certainly isn't a good term for "life-threatening total scam". Homeopathic "medicines" are strictly just pure water - or some other pure but strictly non-medicinal substrate. As such, they offer no treatment whatever - beyond (perhaps) a placebo-effect. However, the placebo effect only works if you don't realise you're being given a placebo...so that's pretty much blown away now that I've explained it to you. Not all medicines that are labelled as "Homeopathic" actually are - there has been a prominent case recently where 'Zicam' (a supposedly homeopathic cold treatment) is permenantly destroying people's sense of smell due to the large amount of zinc in the stuff. That's not "homeopathic" at all - they were just using that label to avoid having to go though proper drug testing procedures...with predictable consequences. This seems like a no-brainer to me - you have a choice between spending a lot of money on a small bottle of water (at best) or some utterly unproven and probably inadequately tested substance like Zicam (at worst)...or you can buy something that has had to go through stringent testing under rigorous scientific conditions through both animal and human studies. That's not to say that "conventional" medicines are 100% safe - or 100% efficacious - they aren't - but the rational choice is between doing nothing (and spending nothing) and risking the conventional cure. Buying the homeopathic stuff is (at best) the same as doing nothing whilst flushing dollar bills down the toilet - or (at worst) taking something like Zicam - which is formulated with actual active ingredients - just like a conventional medicine - but which has NOT had to go through all of the testing phases. Either way - you're better off doing nothing or going with conventional medicine. SteveBaker (talk) 14:23, 26 June 2009 (UTC)

"However, the placebo effect only works if you don't realise you're being given a placebo...so that's pretty much blown away now that I've explained it to you." Not necessarily; the placebo effect is a wonderful thing. For example, they might not really believe you deep down. Or the experience given by the homeopath/packaging might be sufficiently reassuring. Or, just knowing that some people find the treatment helpful even though there is no active ingredient can be enough :) Of course, you'd want to chose something that actually didn't have any active ingredients (Zicam being excluded by this). 89.168.19.118 (talk) 18:24, 26 June 2009 (UTC)

Placebos are, in point of fact, effective. It has been scientifically established that the body has some kind of improved healing response that can be triggered by the ingestion of sugar pills. If you believe that—and as a rational empiricist you should—then why shouldn't the sugar pills work on you? -- BenRG (talk) 22:50, 26 June 2009 (UTC)

An interesting point... The problem is, I know it isn't the sugar pill that has the effect, it is my belief in the sugar pill. If I believe it will work, then it will work, so my belief is rational. If I believe it won't work, then it won't work, so my belief is, again, rational. Since either belief is rational, I'm not sure I can make myself switch from one to the other, and I'm likely to start in the latter case... --Tango (talk) 17:15, 27 June 2009 (UTC)

--Jessica A Bruno 22:14, 28 June 2009 (UTC)Thanx for all of the info that you give me on my question. Have say its ts interesting for sure. --Jessica A Bruno 22:12, 28 June 2009 (UTC) —Preceding unsigned comment added by Jessicaabruno (talk • contribs) 16:42, 26 June 2009

Note that regardless of whether regular doctors were labelled "allopaths" in the 19th century, the graduates of well known medical schools practiced the removal of large amounts of blood from the patient, based on no evidence, and the administration of poison, calomel, which caused serious long-lasting consequences., The British medical journal "Lancet" is named after the device that such doctors used to remove a pint or so of blood from the patient for no obvious reason. If a patient was kicked by a horse, bleed and purge. If he got smallpox, bleed and purge. If he had cancer, bleed and purge. Quack, quack, quack. Edison (talk) 02:32, 27 June 2009 (UTC)

Edison, what you say is true (though perhaps a little overstated), and historically interesting, but unless one plans to hop into a time machine and travel back a century or so to seek medical attention it's not really relevant to a discussion of present day treatment choices. 87.81.230.195 (talk) 15:24, 27 June 2009 (UTC)

The difference, Edison, is that the so-called 'allopaths' eventually abandoned their tradition-driven, faith-based approach. (I use 'faith-based' in the broadest sense — they simply trusted that the received wisdom of their elders was correct, without supporting evidence or testing.) Homeopaths are still using the same approaches promulgated in the nineteenth century by Hahnemann. While homeopathic remedies are certainly less harmful than the bloodletting and calomel of a century ago, they remain as effective today as a glass of water. TenOfAllTrades(talk) 15:49, 27 June 2009 (UTC)

I had an ear infection cured by the local witch doctor once after the conventional evidence based doctor had made it much worse and I was in really bad pain. So I'm happy to give unconventional medicine a bit of slack. I must admit though I really cannot see why people believe in homeopathic medicine, and an allergy to it sounds even stranger. Dmcq (talk) 16:55, 27 June 2009 (UTC)

Wow! That's just incredibly weak thinking!

• How do you know that your infection didn't simply get better by itself simply as a result of your own body fighting it off?
• How do you know that the evidence-based doctor didn't prevent it from becoming much, much, MUCH worse - although it still got "much" worse?
• How do you know that the conventional doctor's treatment didn't take longer to take effect than you thought - meaning that he was the one who ultimately cured you?
• How do you know that your recovery wasn't a consequence of the placebo effect?
• How do you know that the conventional doctor didn't make a mistake? Or perhaps the pharmacist made an error? Or perhaps you didn't follow the instructions on the label properly?
• How do you know that you didn't pick up ANOTHER infection between the doctor diagnosing the first problem and your eventual recovery?

Every one of those things perfectly explains the facts - and every one of them is VASTLY more likely to be the cause of the ensuing events than some kind of arcane black magic! Why on earth would you choose to believe the crazy explanation when there are so many 'sane' explanations to choose from?

Reliance upon a single experienced "result" is precisely the reason why these kinds of alternative medicine approaches go so badly off the rails - people are only too likely to fall into belief in all sorts of bizarre superstitions as a result. We know very well that the body is fighting infections all by itself - we know that the placebo effect really works - so only experiments that carefully control for those things and work on sizeable populations are valid. If you're going to go around believing in the results of single trials like that - you'll believe in just about anything. Two days ago I ate a banana, crossed the street - and DIDN'T get run over by a car. Yesterday, I crossed the same street at the same time of day and got hit by a car. Ergo banana's protect against car accidents. That's PRECISELY the reasoning you're using here...precisely...and it's really pretty pathetic.

SteveBaker (talk) 01:07, 29 June 2009 (UTC)

I tend to the idea the conventional doctor was just not very good at his job. Other people had been to the witch doctor before and he provided a good service. Also he did know quite a bit about modern medicine which he wouldn't have known if it wasn't for the scientific method which developed it. Dmcq (talk) 15:40, 1 July 2009 (UTC)

Total number of medical articles

Dear Reference Desk, can you please tell me how many total medical articles are on Wikipedia. I would greatly appreciate it. I couldn't find a category for medicine to count myself. Greatly appreciated. Crossposted at WT:MED. 207.59.144.196 (talk) 00:13, 26 June 2009 (UTC)

I've responded at Wikipedia_talk:WikiProject_Medicine#Question. -Optigan13 (talk) 00:35, 26 June 2009 (UTC)

Solar eclipse

Hi. Is it safe to view the partial phases of a solar eclipse, using two sheets of X-ray film on top of each other? Totality is not included in this, and of course the Diamond ring and Bailey's beads are not part of totality. How many sheets would be needed to be a safe substitute for solar eclipse glasses? Thanks. ~AH1^(TCU) 00:28, 26 June 2009 (UTC)

The safest way - by far - for an amateur sun-watcher to do this is to make a pinhole camera - a large sheet of cardboard with a pin-hole in the center can be used to project a picture of the sun onto any convenient surface...like a second sheet of white cardboard. You can test the gizmo out in normal sunlight before the big event...you need to be familiar with it and not fiddling around during the limited time available. The smaller the pinhole, the sharper the picture...but smaller pinhole means dimmer image - so you can't project the image and still be able to see it well. Experiment with it - if you get it right, you can even see sunspots and such on a normal sunny day. SteveBaker (talk) 00:49, 26 June 2009 (UTC)

But don't expect to see sunspots at the moment - there aren't any! (Well, there is one tiny one at the moment that is just fading away, but generally the sun is unusually inactive at the moment.) --Tango (talk) 00:56, 26 June 2009 (UTC)

Good point! SteveBaker (talk) 13:59, 26 June 2009 (UTC)

AH1: you have a telescope, so you can use it to project an image of the Sun onto a sheet of paper. That uses the same principle SteveBaker was mentioning, but the image is going to be a lot brighter and clearer with a telescope than with a pinhole. --Bowlhover (talk) 20:50, 27 June 2009 (UTC)

For people without a telescope, binoculars also work perfectly well. I've watched a Transit of Venus by projecting it onto a piece of paper with binoculars (I couldn't get it set up very well so had to do it mostly hand-held, so the image wasn't at all steady, but it was good enough to see the black dot moving across). --Tango (talk) 21:01, 27 June 2009 (UTC)

Let's be REALLY clear about this - you don't look at the sun through the binoculars or telescope! That will blind you in less time than you can blink. (Literally!) The idea is to point the business end of the binocular/telescope at the sun - and place a screen some distance back from the eyepiece. If you put the screen too close - the concentrated heat/light can cause fires - so be careful. Trust me - try the pin-hole approach - it works just fine and it's safe. SteveBaker (talk) 00:48, 29 June 2009 (UTC)

You get a bigger, sharper image with binoculars and they are perfectly safe (as long as you remember not to use your retina as the projection screen!). For watching an eclipse, that isn't really necessary and a pin-hole is fine, but for a transit or for observing sunspots, it does help. --Tango (talk) 04:13, 29 June 2009 (UTC)

Please see this page [2], and for further detail this page [3], both by NASA eclipse guru Fred Espenak. Multiple layers of some films may be safe, but it depends; there are other options that you can know are safe. --Anonymous, 23:07 UTC, June 26, 2009.

To reinforce the message, just because some ad hoc filtration makes the visible image tolerable, doesn't mean you won't seriously damage your sight, because it's the infra-red light you can't see (and which visible light filters may not block) that does most of the damage to your retina. Smoked glass and darkened photographic films are known to be inadequate. Stick to products sold for the purpose (because their manufacturers' arses are on the line), or items widely certified by professional astronomers to be safe - a certain grade of welding mask has been shown to be adequate, for example, but you'd need to both check the safe grade and that the mask you've got uses the same grading system. 87.81.230.195 (talk) 15:17, 27 June 2009 (UTC)

I thought it was UV that was the main problem, not IR (although either could be problematic, I imagine). That's why cheap sunglasses can do serious harm, they don't protect against UV but do cause the pupil to dilate due to reduced visible light which means more UV enters the eye than if you didn't have the glasses at all. --Tango (talk) 17:10, 27 June 2009 (UTC)

The source I cited says IR is the main problem. Anyway, a safe filter will attenuate everything from IR through visible light to UV. --Anon, 20:35 UTC, June 28, 2009.

The discussion above elegantly explains why you need to use a pin-hole camera! It's really easy to screw up and THINK that you've dimmed down the light enough to be safe when you haven't. Since we value our eyesight so much - don't take a chance on it being the IR or the UV that you're trying to block...it's just too big a risk. A pinhole camera is unconditionally safe. The other methods are not. SteveBaker (talk) 00:48, 29 June 2009 (UTC)

It is safe to use a proper filter, and it means you get to look at the sun instead of just an image of it. What is not safe is an improvised filter. --Anon, 04:08 UTC, June 29, 2009.

I agree. My preferred way of watching an eclipse is to get some of the eclipse glasses that are always around in the run up to any eclipse. (Make sure you get them from a reputable source, of course.) --Tango (talk) 04:13, 29 June 2009 (UTC)

Your preferred way? Wow. You must have seen a lot of solar eclipses to have a preferred way. Do you travel to chase them? --Bowlhover (talk) 21:43, 29 June 2009 (UTC)

Not that unusual. We've seen 3/5 (me/hubby) so far and many people we meet on tours or at the viewing sites have seen more than that. Every one is a bit different and every culture has their own way of enjoying it. My "preferred" way is no. 14 welder's glass Eye protection#Protection against light. You can mount it in front of the lens of a camera. That would be before the light hits the equipment not on the other end. (Be sure to mount it securely and don't leave any gaps.) or use welder's goggles for direct viewing as the following poster recommends. If you use viewing glasses provided at the site (or from any other place) discard any crumpled or creased glasses. The foil might have been damaged. 71.236.26.74 (talk) 13:25, 4 July 2009 (UTC)

The best way to view a solar eclipse with out taking an image would be to simply wear a welders mask/goggles i have witnessed two such events this way one when i was very young and one a few years ago each time with a welders mask on. it was perfect.Chromagnum (talk) 08:34, 2 July 2009 (UTC)

spring with variable controllable stiffness ?

Hi,

I'm trying to create a simple mass-spring vibratory system but the problem is that I need this spring to be of a controllable stiffness, like if I wanted to double the stiffness I would or the opposite. Can anyone help me with that ??? I tried using a double acting cylinder for that matter but it didn't work...

How about a flat strip of spring-steel that can be clamped in different places? You're not changing the intrinsic springiness of the material, but you're getting comparable control over its effect for the spring as a component in your system. Does a bimetallic strip change its spring constant with temperature, or just its neutral position? Some are self-heating with current, or else you could attach a small heating element to it. If you can settle for fixed incremental changes (vs continuously variable), a flat piece of spring steel could be stiffened by adding various numbers and strengths of reinforcements to the face, or you could add various numbers of stiff wire between two parallel anchors. DMacks (talk) 03:43, 26 June 2009 (UTC)

Perhaps a section of hose pipe that you could pressurize with air or hydraulic oil or something? Of perhaps a flexible tube with a steel cable running inside it (like a bicycle brake cable) that you could alter the tension of? What's it for? SteveBaker (talk) 13:57, 26 June 2009 (UTC)

Civil and earthquake engineers use active hydraulics to control building foundation stiffness during an earthquake. Active control suspensions and base isolation technology are essentially varying a spring constant (for very very large, stiff springs). Automotive engineers use active hydraulics for active suspension, such as Active Body Control. Nimur (talk) 16:41, 26 June 2009 (UTC)

I don't think any automotive systems work by varying the spring stiffness - they mostly either adjust the drag force of the damper (eg by using fluids that vary their viscosity according to the amount of electric current applied to them) - or they have an active component that applies a force to the wheel via a hydraulic or electrically actuated piston. I suppose with a computer driving that piston, you could simulate springs of any desired stiffness in software and apply the appropriate amount of force to the wheel depending on how it's moving...but that's a rather different thing from an actual spring with variable stiffness. SteveBaker (talk) 17:46, 26 June 2009 (UTC)

In my interpretation, any object which approximates Hooke's law - that is, produces a reaction force approximately proportional to the displacement distance - is a spring. This includes hydraulic dampers and active suspension systems. The "active" part means that something (typically fluid pressure) is controlled to change the effective reaction force constant ("spring constant"). Nimur (talk) 19:55, 28 June 2009 (UTC)

Hydraulic dampers don't approximate hooke's law. The force that the damper applies is independent of the displacement (at least until you hit the end-stop) - the force they apply is a function of the velocity that they are moving. That's why they damp down vibration. SteveBaker (talk) 00:41, 29 June 2009 (UTC)

Gah! Steve! You know that's the "high school physics" version, where spring forces are exactly equal to k*x and damping forces are exactly equal to k*dx/dt! A real hydraulic plunger will exert a force that is some combination of these terms, for appropriately chosen constants k. In the language of proper physics, a real-world-hydraulic-plunger attached to a mechanical apparatus can be modeled as a second-order equation; it will then have a system response, $a*x+b*{\frac {dx}{dt}}+c*{\frac {d^{2}x}{dt^{2}}}$, where x is the displacement from equilibrium position; and if b >> a then the hydraulic plunger is a "damper" and if a >> b then it is a "spring" (or, see Damping for more popular "conventional" notation). The designer of an active control system would select appropriate mechanical implementations, considering the mass, parasitic frictional and other forces, etc. - and could select a system that behaves best for the problem needing to be solved. Nimur (talk) 16:36, 30 June 2009 (UTC)

Bouncing car. Cuddlyable3 (talk) 10:07, 27 June 2009 (UTC)

Thymol blindness?

Are there any health risks by getting thymol in your eye? --69.148.26.115 (talk) 04:24, 26 June 2009 (UTC)

What you are after is the material safety data sheet (MSDS) for thymol, such as this one. Which claims "Harmful if swallowed, inhaled or absorbed through the skin. Eye, skin and respiratory irritant. Eye contact may cause serious harm. " So the answer seems to be yes, bad for eyes. Vespine (talk) 05:37, 26 June 2009 (UTC)

I treat MSDSs with much skepticism, after reading one for water, which told me to avoid skin and eye contact, and if contact did occur I should flush with... water. http://www.biosci.ohio-state.edu/safety/ChemMSDS/WATER-MSDS.html So I'd interpret "may cause serious harm" as meaning anything from "will kill you" to "is good for you". Aaadddaaammm (talk) 10:45, 27 June 2009 (UTC)

I suspect that the linked MSDS for water is either a joke (there have been others on similar lines, usually under names like Oxygen Dihydride), or an example/template to aid the construction of entries for other substances. Having myself dealt extensively with MSDS's in a professional context, I would strongly recommend treating MSDS advice very seriously unless one has very good evidence that it's erroneous. Naturally manufacturers will err on the side of caution, and I have read of some specialist lab chemicals whose deleterious properties may have been considerably overstated, but suggesting that all MSDS information is unreliable and can safely be ignored borders on the irresponsible. 87.81.230.195 (talk) 15:03, 27 June 2009 (UTC)

MSDS often consider large-scale/industrial and/or worst-case situations, not "small amounts" for many common chemicals. A real [MSDS for sand] does seem excessive. I'm not worried about sandboxes and the beach, but if I'm scooping huge amounts and there's lot of fine powder (vs larger crystals) you bet your @@@ I'm wearing a dust-mask or at least keeping my face away from it. I suppose it's only a matter of time until all beaches are closed as a health risk. DMacks (talk) 20:38, 27 June 2009 (UTC)

Anyone can write an MSDS, yea? And they aren't really checked by any official body, yea? My comment was really to emphasise these points, and was definitely not suggesting all substances be treated carelessly, rather that almost everything should be treated as dangerous. And your sand MSDS is also pretty ridiculous;

Lab [not industrial scale, lab scale] Protective Equip: GOGGLES; LAB COAT; VENT HOOD; PROPER GLOVES 
Ingestion: If large amounts were swallowed, give water to drink and get medical advice. [sure medical advice, but why drink water?]
Skin Contact: Wash exposed area with soap and water. Get medical advice if irritation develops.

Aaadddaaammm (talk) 09:02, 28 June 2009 (UTC)

Rising cream

I poured the cream off the top of a jar of raw milk that I had in my fridge into a tall mug (all the jars were dirty). I left it there overnight. When I looked at it again in the morning, it seemed to have gained some volume. I remember thinking that it was just about to the brim and when I looked in the morning, it was quite nearly overflowing. What would have caused this? Would it just be from the temperature increase between my fridge and the ambient temp in the kitchen? Or was this due in part to the spoiling of the cream? Oh, it was maybe a quarter inch more liquid in the morning. Dismas|^(talk) 04:41, 26 June 2009 (UTC)

Could it be water condensation from the air in the fridge? At fridge temps, moisture condenses naturally from the air, and in your case it would sink to the bottom of the tall mug, and the cream would float on top of it. I don't think that there would be a quarter inch of water in the mug after just one night in the fridge, but there might be if it was a really narrow mug or if the air humidity was unusually high. As for the spoiling of the cream, it definitely wouldn't spoil after sitting in the fridge overnight, so you need not worry about that. FWiW 76.21.37.87 (talk) 07:05, 26 June 2009 (UTC)

Sorry, I guess I should have been more clear. I wasn't standing inside the fridge, so when I said that I "left it there", I meant that I left it on the counter where I had poured off the cream. So, cream in mug on counter, rest of milk (minus one glass for the missus) in the fridge. Also, in case people are wondering or it makes a difference, I should probably point out that I was skimming off cream from raw milk. My wife milks it out of a friend's Jersey cow. It's quite tasty with the cream shaken into the milk but my wife insists that the cream be poured off. something about fat and heart attacks... Women! :-) Dismas|^(talk) 07:35, 26 June 2009 (UTC)

Is the milk and cream Pasteurized? 65.121.141.34 (talk) 12:59, 26 June 2009 (UTC)

By definition, raw milk is not pasteurized. Nimur (talk) 14:06, 26 June 2009 (UTC)

Ok, was not sure if raw milk was just not separated or unpasteurized and not separated. 65.121.141.34 (talk) 14:14, 26 June 2009 (UTC)

Good chance that it was fermenting. "Spoiled" is not quite the right word -- if it ferments in the most common way, this is the process that leads to creme fraiche and sour cream. Looie496 (talk) 15:52, 26 June 2009 (UTC)

I should point out that drinking raw milk that's been left out overnight is dangerous. Most of the time it will be fine, but every once in a while it will kill you. Historically, many people used to die from drinking spoiled milk, until we invented pasteurization and refrigeration. StuRat (talk) 17:03, 26 June 2009 (UTC)

Whilst not wishing to detract from StuRat's valid warning, I feel that I and millions of others have not put ourselves at serious risk by drinking raw milk that has not been refrigerated. The taste usually indicates whether the milk is still fit to drink, (though there are some bacteria that do not add sour tastes). Pasteurization and refrigeration certainly improve safety and keeping time, and micro-filtration makes the product even safer, but even these "clean" products can become contaminated by nasty bacteria. Dbfirs 20:29, 26 June 2009 (UTC)

Thanks, Stu, but I didn't drink any milk that had been left out. It was the cream that was left out and it is fed to our chickens who absolutely love the clabber. Dismas|^(talk) 05:40, 27 June 2009 (UTC)

I wonder if that has any relation to the Clabber Girl brand. Did they used to sell clabber ? StuRat (talk) 17:37, 27 June 2009 (UTC)

acute liver failure

what are the symptoms of acute liver failure and is it possible for the person to die in 48hrs

We are not allowed to give medical advice here. If this is a health question, call your emergency number (i.e. 911 or equivalent) NOW. If it's a homework question, search the web. -- Aeluwas (talk) 08:14, 26 June 2009 (UTC)

No medical advice was asked for. Please see acute liver failure, King's College Criteria, or this site. The second question isn't too meaningful, as death within 48 hours may mean death from something that's been going on for a while but wasn't noticed until 2 days before it killed someone: that is, almost anything that can kill you and progresses rapidly can go unnoticed until 48 hours before death. -Nunh-huh 10:33, 26 June 2009 (UTC)

Consistent pulsing in ear.

This question has been removed. Per the reference desk guidelines, the reference desk is not an appropriate place to request medical, legal or other professional advice, including any kind of medical diagnosis, prognosis, or treatment recommendations. For such advice, please see a qualified professional. If you don't believe this is such a request, please explain what you meant to ask, either here or on the Reference Desk's talk page.

This question has been removed. Per the reference desk guidelines, the reference desk is not an appropriate place to request medical, legal or other professional advice, including any kind of medical diagnosis or prognosis, or treatment recommendations. For such advice, please see a qualified professional. If you don't believe this is such a request, please explain what you meant to ask, either here or on the Reference Desk's talk page. --~~~~

We cannot offer you evaluation of your diagnoses or prognosis. If you have concerns about your medical condition, you need to speak to a qualified medical professional. TenOfAllTrades(talk) 13:21, 26 June 2009 (UTC)

Debye-Huckel lamitting law

what is the main statement of Debye-Huckel limitting law? why it is say limitting law?Supriyochowdhury (talk) 18:45, 26 June 2009 (UTC)

We have an article on the Debye–Hückel equation, which explains the law in exhaustive detail. The main idea behind it is that it is a method to calculate activity of ionic solutes in solution. In your standard high-school level chemistry class, solute effects (i.e. colligative properties) are calculated based on solute concentration; however this is a heuristic approximation. The relevent property of a solute is not its concentration, but its "activity", which by a bit of circular reasoning is defined as "the property of a solute that effects the way it changes the properties of a solution" or something like that. It's not really a concrete, measurable property like "concentration" is, and concentration is a decent approximation, which is why it is often used. However, the DH law is an attempt to create an equation which provides a better, more accurate way to calculate activity than simply to substitute concentration for it. --Jayron32.talk.contribs 18:59, 26 June 2009 (UTC)

placebo effect

Does the placebo effect work on non-humans, or are humans the only ones who can have this do to a more developed brain? 65.121.141.34 (talk) 19:50, 26 June 2009 (UTC)

A google of "placebo effect animals" yielded this paper. Also from placebo, "placebos can act similarly through classical conditioning, where a placebo and an actual stimulus are used simultaneously until the placebo is associated with the effect from the actual stimulus." Many animals can be conditioned to respond to a placebo: i.e Pavlov's dog. Sifaka ^talk 22:59, 26 June 2009 (UTC)

Be careful. The placebo effect does not just effect the patient. It will also effect anyone trying to judge how well the patient has improved. This is why medical trials are double-blind. APL (talk) 01:13, 27 June 2009 (UTC)

That, technically, is not a "placebo effect" since the judgment of others presumably has no influence on the actual condition of the patient. If, however, the doctor tells the patient that he has improved, that statement may very well cause a placebo effect. Medical trials are conducted double-blind to prevent experimenter bias. 76.11.230.33 (talk) 03:11, 27 June 2009 (UTC)

The reason placebos don't work as well in non-double-blind experiments is because the patient may not be as convinced that the treatment will work if the doctor doesn't think it will work (doctors are hired for their medical abilities, not their acting abilities). --Tango (talk) 17:08, 27 June 2009 (UTC)

I think the article Sifaka linked is a good answer. To summarize briefly, if an animal often receives a particular type of treatment and feels better afterwards, they may be conditioned so that they expect similar results from the same experience in the future, even if the actual treatment administered was totally different. But research is inconclusive. Dcoetzee 04:54, 27 June 2009 (UTC)

polydactylism

I watched a movie the other night (I forget the name). It involved a lot of genetically modified humans in a not-too distant future scenario. In one of the scenes, they are watching a guy play the piano, and he is revealed to have like 7-8 fingers on each hand. Are there any living real-life examples of famous pianists, organists, keyboardists, etc... that had at least 1 additional functioning finger? 65.121.141.34 (talk) 20:34, 26 June 2009 (UTC)

This doesn't help answer your question, but for what it's worth, the name of the movie is Gattaca. Red Act (talk) 20:59, 26 June 2009 (UTC)

Wikipedia's article on Polydactyly does list some real-life notable polydactyls, guitarist Hound Dog Taylor is listed as being one; our article however does not contain any citation to verify this little "factoid". --Jayron32.talk.contribs 21:01, 26 June 2009 (UTC)

Someone posted a question on the Entertainment desk just the other day (presumably it will soon be archived here), querying a statement in Wikipedia that a certain musician has an extra finger. It was unsourced and nobody found a confirmation, so it was suggested that this was just Wikipedia vandalism. --Anonymous, 23:12 UTC, June 26, 2009.

I have a vague memory that someone composed a (piano?) piece that is intended to be played with 6 fingers on at least one hand, but I can't remember where I read this. It could very well be a case of false memory. Maybe it will jog someone else's memory. Sifaka ^talk 23:05, 26 June 2009 (UTC)

I believe the vast majority extra fingers aren't sufficiently functional to be used to play the piano, so it seems unlikely. It would have to have been written for a specific person, if it exists. No-one would write such a piece unless they knew a good pianist with 6 functional fingers on one hand, and there can't be many such people. --Tango (talk) 23:23, 26 June 2009 (UTC)

This forum claims Mozart and Handel have both written pieces for polydactyls, but given the name of the site I am taking that with a large pinch of salt until someone can reference the actual music. SpinningSpark 23:47, 26 June 2009 (UTC)

Given that the word "hoax" appears not once, but twice in that URL, I'm going to take it with two large pinches of salt! --Tango (talk) 00:02, 27 June 2009 (UTC)

MuseumOfHoaxes is itself a reliable source, and the article Spinningspark linked does not claim Mozart wrote pieces for polydactyls. One of the reader comments does, and comments on any website are bound to be unreliable. --Bowlhover (talk) 03:54, 27 June 2009 (UTC)

The way I always heard the Mozart story was that he had a bet with another composer (whose name escapes me)about who could write a piece the other cannot play. Mozart won by having two simultaneous notes at each end of the piano and a third in the middle, which he played with his large nose. The size of the nose is the only part of this I can verify. - KoolerStill (talk) 09:36, 27 June 2009 (UTC)

The English music hall entertainer Harry Relph, better known as Little Tich, had six (perfectly formed and fully functioning) fingers (including the thumbs) on each hand (as well as six toes on each foot). He was a competent musician who wrote much of the accompanying music for his stage acts, and was an accomplished pianist, according to his biography (which was co-authored by his daughter Mary Tich). 87.81.230.195 (talk) 14:47, 27 June 2009 (UTC)

While I am unaware of people who have that condition and use it to their advantage in playing the piano, it is plausible, due to the usefully corruptable nature of DNA that lifeforms have been using to their advantage since life began. On a side note, I believe the movie you are thinking of is Gattaca with Jude Law and Uma Thurman. ~fl 09:40, 28 June 2009 (UTC)