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June 12

What biotech company is doing the study that replicates ccr4 immunity for people with hiv?

A few months ago I read a news article that a biotech company in South San Francisco or San Bruno is in the middle of human trials for a therapy where people with HIV are infused with t-cells that are adapted to not allow hiv to enter them similar to the ones that people with natural immunity have and that it was promising research because these t cells were replicating themselves in most people in the trial on their own. I want to find this article as some people I told don't believe me or want to know more and I want to look into the company, I also want to expand the article on the HIV timeline and Hiv treatment articles.Thisbites (talk) 00:32, 12 June 2011 (UTC)

I think this is [1] Irvin S. Y. Chen, head of the UCLA AIDS Institute. "He is currently engaged in a start-up company for HIV-1 genetic therapy involving collaborations with UCLA, Salk Institute, and Cal-Tech." Also [2], [3]. [4] says he formed the company with David Baltimore, former president of Caltech. There are various bits of flotsam [5] floating around that link Chen and Baltimore with Calimmune, a California company headquartered in Tucson, Arizona? - it isn't clear to me that this is the company. Wnt (talk) 02:40, 12 June 2011 (UTC)

I distinctly remember that the trials were going on in San Bruno/South San Francisco.Thisbites (talk) 05:05, 12 June 2011 (UTC)

Well, [6] ($20 million) makes it sound like Calimmune is doing just the right kind of study to match your criteria: "methods to transduce autologous hematopoietic progenitor stem cells (HPSC) with a viral vector delivering a specific interfering short hairpin RNA (shRNA) designed to block production of CCR5. In addition, since combination treatment strategies are often more effective than monotherapy, the applicant proposes to add a second inhibitory component to the vector, a gene encoding an inhibitor of virus-cell fusion." I should note however that there are considerable obstacles that come to mind right off. First, all sorts of gene therapy have been under the cloud of potential cancers when DNA goes into the wrong spot in the genome, and these immune cells will be undergoing rapid turnover in people prone to AIDS lymphoma already. Next, RNA interference isn't 100%. They say the cells may be protected anyway since the virus is less likely to bind, but is there really an excess of virus? If not, then the virus can just drift past a hundred missing receptors and bind the one that is there, without any delay. Finally, there's the matter of whether the gene therapy can be "rejected". Every once in a blue moon I've read the strangest claims about DNA being rejected by the immune system, or antibodies somehow getting into the cytosol of the cell. More recent publications include [7] and [8], a less radical claim that viruses bring antibodies into the cell with them that trigger special interfering factors inside the cell. But the point is this: we don't know how the body will respond to long term gene therapy. I can picture for example that the hairpin RNAs found together with the antibody-tagged HIV virus will be tagged somehow as foreign RNA, diced up, and the inserted genes end up being tagged as "spam" by methylation or chromatin changes. Wnt (talk) 18:23, 12 June 2011 (UTC)

Also that those links are for bone marrow/stem cell style treatments. What I read was not a bone marrow transplant. It was modified blood of the patients themselves to alter their t-cells so that they do not have ccr4 receptors. Furthermore there was mention that it was believed to cost 90-120 thousand dollars for the one-time treatment and that that was considered good since hiv medicines can cost upwards of 18k a month.Thisbites (talk) 05:09, 12 June 2011 (UTC)

I think you mean CCR5-Δ32. I heard some stories about a "healing" (remission below detectable levels) taking place after a bone-marrow transplantation of a donor with the CCR5-Δ32 mutation. Which makes sense as it replaces the T-cells with cells having some receptors missing. I also know of companies which offer genetic testing for the CCR5-Δ32 mutation. There is evidence that people with CCR5-Δ32 mutation are less likely to develop aids, and respond better to treatment. It may also be possible that people with CCR5-Δ32 are less likely to get infected, but this has not been researched properly at the moment and might be wrong. Introducing a CCR5-Δ32 mutation into someone's blood might be possible, but I guess a bone-marrow transplantation is a much easier, and already feasible way (even though much more risky). I don't know about recent research though --helohe (talk) 08:22, 12 June 2011 (UTC)

Also note that this treatment, even if successful, would make the person more susceptible to the West Nile virus. On the other hand, it would also give him/her better immunity against smallpox (and possibly black plague as well). -- An American ultranationalist 67.169.177.176 (talk) 02:21, 13 June 2011 (UTC)

Vulcan hearing

It is well known in the Trek universe that Vulcan's have superior hearing. For the most part, it seems people associate this with the shape of their ears. I know that animals can physically move their ears to hone in on a sound (e.g. deer listening for predetors). Since Vulcans cannot move their ears (like an animal, anyway), what affect (if any) does the shape of their ears have on their ability to hear? 99.250.117.26 (talk) 01:54, 12 June 2011 (UTC)

I'm not a Star Trek fan, so I can't tell you for sure, but generally larger ears (such as those of the elephant or the fennec fox) are better at capturing and focussing sound waves, which translates to better hearing. 67.169.177.176 (talk) 02:09, 12 June 2011 (UTC)

There are stores that sell "Vulcan ear" costumes to those Trekkies... they don't work as hearing aids. I think external ears in animals that enhance acuity are distinguished more by a concave shape, which allows them to concentrate sound to a single point. Wnt (talk) 02:14, 12 June 2011 (UTC)

I can't see the shape of their ears making any difference. I don't think it's ever been said on the show that they do (that they have superior hearing is stated, but not the cause). Vulcan's also have superior strength and longevity. I think they are made to be so superior physically so that it's all the more impressive when the emotional humans always better them. --Tango (talk) 13:13, 12 June 2011 (UTC)

This is, of course, what is called fiction, but do keep in mind that the Vulcan (Star Trek planet) atmosphere is less dense, and hence carries less sound energy. Presumably Vulcans have to have more sensitive hearing to have hearing as good as other species which live in thicker atmospheres. μηδείς (talk)

Interesting... Do they also have bigger lungs and better hemoglobin to prevent hypoxia in such a thin atmosphere? 67.169.177.176 (talk) 02:06, 13 June 2011 (UTC)

The "Vulcan equivalent of hemoglobin" is diagrammed here. Clarityfiend (talk) 02:27, 13 June 2011 (UTC)

All I can say to that is, they must be a really crabby bunch... 67.169.177.176 (talk) 06:40, 13 June 2011 (UTC)

The shape of the ear does have an effect on hearing. Sound pressure levels at the human eardrum are typically 7-18dB higher in the 1 kHz to 6 kHz frequency range (essential for good speech reception) than they would be without the pinna. Table 1 on this page gives a breakdown of this. Si1965 (talk) 12:11, 13 June 2011 (UTC)

Probability Of Destruction In "Super 8"

I asked this question in the "Entertainment" section of the Reference Desk as well, but I feel that it pertains to both categories. Hey everybody. I've been wondering something about some of the special effects in the newly-released movie Super 8, which came out in theaters on June 10th, 2011. In it, there is a horrible train crash that involves a mid-sized pickup truck (think mid-90's F-150) driving head-on at full speed into a diesel freight train travelling at well over 50 mph. The collision immediately results in an explosion and the locomotive grinds to a halt. But the filled freight cars behind it continue to shoot forward under their own momentum an end up flying everywhere. This continues to occur as the rear of the train continues moving forward. What makes me think that this is unlikely is the immense speed at which the rear of the train continues to move. I mean, of course the effects of inertia would cause the cars to continue moving, but would they really move at such speed? If you have not already seen the movie, here is a link to that particular scene on the Internet Movie Database: Clip 1, and here is another that is longer, but shows a more complete view of the crash: Clip 2. If anybody could help explain or describe this better to me, it would be much appreciated. Basically, all I want to know is, is this scene probable, or is it simply "movie magic" that looks realistic, but defies the laws of physics. Thanks! Stripey the crab (talk) 02:49, 12 June 2011 (UTC)

Those missing links to IMDB are Clip 1 and Clip 2. Red Act (talk) 02:54, 12 June 2011 (UTC)

Perhaps you should have responded to and thought about my response on Wikipedia:Reference desk/Entertainment before posting here. The film is science fiction, not science. Putting the same question on two ref desks means that responses are dispersed. Not a good move. HiLo48 (talk) 03:00, 12 June 2011 (UTC)

Red Act, thanks, I forgot about that. :P And User:HiLo48, sorry about that. I posted it here, then went back to check at the Entertainment section. And despite the responses being dispersed, it's not that hard to navigate back and forth between two web pages, or easier still, two tabs. As for being a bad move, on the contrary - you expose the question to more people. I usually spend my time strictly on the Science section. I hadn't even visited the Entertainment section before today, and I'm sure I'm not the only one out there who behaves similarly. But thank you for your response, and for your time. It is much appreciated!  :) Stripey the crab (talk) 03:12, 12 June 2011 (UTC)

It's clearly a CGI train, so of course it's not going to precisely do what a real train would do. However, I don't see anything in either clip that super obviously defies the laws of physics. Train crashes can indeed be immensely destructive, as a Google image search readily shows.[9] Red Act (talk) 04:05, 12 June 2011 (UTC)

What was less credible to me was that the truck's driver was still alive, the kids weren't harmed, and their camera and car survived. But it was sill a great movie. HiLo48 (talk) 04:47, 12 June 2011 (UTC)

IIRC, one of the wagons of the train was labeled "explosives". so I guess "theoretically" is is possible. but its unlikely, I have seen a few traincrashes/de-railings and usually I guess it just turns the wagons over squeezes them together etc (similar to what would happen if you do the same in a model-train at high speed)...

Also I don't think a pick up truck would be enough to do much to a train. There have been accidents where some car was in the middle of a crossing, when the train struck, and I guess it just "catapults" the car away, with minor damage to the train. --helohe (talk) 08:13, 12 June 2011 (UTC)

If a pickup truck crashes headon into a locomotive pulling a long freight train, the locomotive itself is so more massive than the pickup that the collision could not possibly bring the locomotive to a halt. The loco and the freight cars would continue at about the initial speed until the application of the train brakes brought the train to a halt. Train brakes are air operated and designed to bring the locomotive and cars to a smooth and safe stop, without the freight cars running over the magically stopped locomotive. The whole scenario sounds bogus. Standard Hollywood garbage, its physics about on a par with Roadrunner cartoons. If the lead locomotive somehow derailed, or it it hit a massive gravel truck or truck load of rolls of steel, the scene would be more plausible. It is still a great scene, cinematically, and I will make it a point to see the movie. Edison (talk) 00:50, 13 June 2011 (UTC)

Edison is exactly correct, the locomotive would not come to a dead stop given it outmassed the truck but the cars behind would have continued at the same speed they were being pulled by the locomotive. What really effs up a movie is when a falling object falls faster than gravity because Catwoman (film) jumped downward. μηδείς (talk) 01:20, 13 June 2011 (UTC)

The truck wouldn't need to itself bring the locomotive to a stop. If the locomotive is derailed by hitting the truck (which is conceivable) it's going to slow down pretty fast which could cause the subsequent cars to pile up. If the train happens to be packed full of explosives (which I have to assume it is by the way everything starts exploding) I guess it could be pretty catastrophic. Rckrone (talk) 04:35, 13 June 2011 (UTC)

I still don't buy it -- even if the engine is derailed and the other cars pile up behind it (pretty unlikely given the small size of the truck), modern high explosives are very stable and will not detonate simply from being jostled in this manner. In order to explode in this manner, the train would have to be carrying either some kind of high explosives with extremely high sensitivity to impact, such as nitroglycerin (implausible, since these types of explosives are no longer used as such, nor transported), or else live munitions with detonators fitted (TOTALLY implausible -- munitions are ALWAYS transported with detonators removed, precisely to avoid a disaster of this type). Or else the train would first have to catch on fire and the flames spread to the explosives (which is possible, but would take a while). But then again, most people don't know what REALLY happens when a train hits a pickup truck, much less what happens when a train derails. And all those peddlers of cheap thrills capitalize on this scientific ignorance to make big bucks... 67.169.177.176 (talk) 07:05, 13 June 2011 (UTC)

Modern explosives tend not to explode even if they catch fire -- it typically takes a combination of pressure and heat to get them to produce anything but an intense flame. --Carnildo (talk) 01:36, 16 June 2011 (UTC)

See what I mean? The train won't explode in this scenario, even if it jumps the tracks -- period! 67.169.177.176 (talk) 08:34, 16 June 2011 (UTC)

Cold fusion applicability

Reading cold fusion confuses me — I understand somewhat of what the proponents claim is happening, but I fail to see the applicability. Let's say that tomorrow someone shocks the scientific community and conclusively proves to everybody's satisfaction that cold fusion really is possible. What possible applications are there for it, aside from reducing the prices for manufacturers of helium balloons? As far as I know, all our uses for fusion rely on the significant amounts of energy that result, whether using the explosion as a powerful weapon, or (if we can figure it out) using a slower process to generate electricity with the very non-cold temperatures that result. Nyttend (talk) 12:17, 12 June 2011 (UTC)

The most common idea that I've seen is that you scale it up to the level of "personal reactors" that would power your household, heat your water, power your car, whatever. It's meant to be small-scale, personal, clean power. (This is part of the alleged conspiracy theory — it would destroy the need for centralized utility companies, oil companies, and so forth. So they've rallied against it, blah blah blah.) Obviously the prototypes don't really intend to do that, any more than Hahn and Meitner's experiments weren't a fission reactor (or bomb). If we could use hot fusion on that scale, we would, but hot fusion requires starting temperatures on the order of millions of degrees Fahrenheit, so getting back what you put into it requires liberating a huge amount of energy. --Mr.98 (talk) 12:49, 12 June 2011 (UTC)

Yes, you are right. Cold fusion would be useful as a source of energy. That's it. That is a extremely important applicability which makes me wonder why you say you fail to see the applicability. Dauto (talk) 18:42, 12 June 2011 (UTC)

I think the question is: if it is cold, then it doesn't generate energy that we can transform into electricity. So is the word cold in cold fusion misused? Or can we generate elecricity without heat or explosions? --Lgriot (talk) 10:25, 13 June 2011 (UTC)

Cold here is a relative term. Cold fusion still leads to temperatures high enough to produce electricity. Dauto (talk) 16:39, 13 June 2011 (UTC)

To put it in perspective, the temperature inside of a conventional coal based electric power plant is of the order of 1000 K while the temperature required for hot fusion is of the order of 100 000 000 K. There is plenty of space in between that would be hot enough to produce electric power but too cold to generate conventional fusion. If fusion is achieved in that range it would be considered cold fusion. Dauto (talk) 16:48, 13 June 2011 (UTC)

Just to clarify (perhaps): the "cold" and "hot" here refer to the temperatures necessary for ignition of the fusion reaction, not to the heat of the reactions themselves. --Mr.98 (talk) 14:10, 14 June 2011 (UTC)

You might be interested in Fusor. 5BYv8cUJ (talk) 18:35, 13 June 2011 (UTC)

Which, to clarify, is hot fusion. --Mr.98 (talk) 14:10, 14 June 2011 (UTC)

Diet by cold/hot air

Would it be an effective diet just to be outside our thermal comfort zone? This way our body would have to burn calories to keep us cool or warm. Which way would be more effective - hotter or colder? Quest09 (talk) 12:32, 12 June 2011 (UTC)

Cold. You don't really use energy to cool down, that would be counter-productive since using energy almost always converts it into heat (energy is never created or destroyed, remember). You cool down by sweating and redirecting blood to the skin. That doesn't really take energy. When you're cold, though, you need to use energy to generate heat (for example, by shivering). I don't think it would be a particularly good way to burn calories, though - you would need to be dangerously cold for it to have a significant effect. You would be better off going for a nice jog. --Tango (talk) 13:22, 12 June 2011 (UTC)

But, if you need 1Cal to heat one Kg of yourself 1 °C, and you put the A/C 3 °C below the comfort zone, you'll end up spending a lot of Calories each day (provided you don't get hungry in the cold), won't you? Quest09 (talk) 13:40, 12 June 2011 (UTC)

No, because food calories are a thousand times larger than the calories for heating water. (I'm not making this up, see calorie.) – b_jonas 08:50, 13 June 2011 (UTC)

He got it right. One food Calorie is one kg (1000 grams) of water for 1 °C. Thermodynamic calories are one gram of water for 1 °C. Hence by saying kilogram he already included the factor of 1000. Dragons flight (talk) 18:56, 13 June 2011 (UTC)

Hmm, okay. Sorry. – b_jonas 09:46, 15 June 2011 (UTC)

You might be interested in Brown adipose tissue. 5BYv8cUJ (talk) 14:03, 12 June 2011 (UTC)

You'll gain weight when you attempt to change the energy balance like this, without drastically cutting back on your energy intake. This is because the body attempts to maintain a stable body weight on the long term. So, unless you go outside the range where the feedback mechanisms the body uses break down, you won't lose weight. Instead, the feedback mechanisms will lead to the opposite result, a modest weight gain, because it will take measures against a perceived threat to its long term energy reserves.

Incidentally, the article Mike Stroud (physician) says that Antarctic explorers can use over 10,000 calories a day (which I've seen described by a simple calorie count of the food consumed from some much earlier expedition). Wnt (talk) 17:59, 12 June 2011 (UTC)

Recent research has pointed to something else you can do to lose weight without dieting: Sleeping for longer. This is because during sleep the metabolic rate is slower. Naively, you may think that you'll gain weight if you sleeep better and longer. But what really happens is that the metabolic rate during sleep is regulated as part of all the feedback mechanisms to maintain a stable weight. Then, because the body will regulate the amount of energy reserves such that it can do without food for some given amount of time, a longer sleeping period means that you need less fat. You could say that the time you sleep counts as virtual fat, and the more virtual fat you have, the less real fat you'll have. The body apparently keeps track of how much you sleep on you get on the long term and uses that to regulate to what degree the fat cells are filled. Count Iblis (talk) 15:12, 12 June 2011 (UTC)

I personally find that it is much easier to lose weight when it is hot. Not because the heat is burning calories, but the heat makes me not feel like eating. Googlemeister (talk) 17:31, 13 June 2011 (UTC)

Electronic compass

I've just bought a GPS unit that includes an electronic compass, i.e. it supposedly doesn't rely on GPS data and functions when stationary, unlike cheaper GPS units which can only determine direction when moving. I was curious to know how the electronic compass worked, but there isn't a Wikipedia article, and the compass article refers readers to fibre optic gyrocompass, so I created a redirect to that article from electronic compass. However, reading the article on fibre optic gyroscope (to which fibre optic gyrocompass refers me) I am not sure I have done the right thing. Does my Oregon 450 GPS unit really contain a laser and lots of fibre optic cable? If not, how does the "electronic compass" work?--Shantavira|^{feed me} 13:27, 12 June 2011 (UTC)

It probably does it with a magnetoresistance sensor like the Honeywell HMC6352 module described at www.cypress.com/?id=1128 -- Finlay McWalter ☻ Talk 13:43, 12 June 2011 (UTC)

A better link is this Philips note (the Philips parts are just the sensor, the Honeywell above implements much of what the Philips note discusses). -- Finlay McWalter ☻ Talk 13:46, 12 June 2011 (UTC)

There is a WK article about that: magnetometer (aka as digital compass). Quest09 (talk) 13:50, 12 June 2011 (UTC)

Thanks. Maybe someone more knowledgeable than me could tweak the various compass articles.--Shantavira|^{feed me} 15:34, 12 June 2011 (UTC)

first magnet

Reading the question above, I wondered how the first magnet / compas needle was created. The only way I can think of to create a magnet is using an electromagnetic field applied to some iron or similar which would require electricity. then again to create electricity (besides using a chemical process like a battery) one needs a magnet to induce an changing electric field in a coil. --helohe (talk) 16:47, 12 June 2011 (UTC)

A lodestone is a natural magnet. You can take a non-magnetic piece of iron (like a needle) and magnetise it by rubbing it in one direction with a lodestone. -- Finlay McWalter ☻ Talk 16:50, 12 June 2011 (UTC)

The English scientist William Gilberd (1544 – 1603) was the first person to study magnetism in any scientific way. He found out how to manufacture magnets as Finlay describes - only natural lodestones were used previously. He also disproved the widely held belief that compasses could be demagnetised by contact with garlic! He was the first to suggest that the earth had magnetic poles - it had previously been thought that there was a big magnetic island in the Arctic that all compasses pointed to. He is credited with coining the word "electricity". He deserves to be better known, but few have heard of him outside of his home town of Colchester. Alansplodge (talk) 17:37, 12 June 2011 (UTC)

Whether by rubbing amber or by using an electrochemical reaction such as the Baghdad Battery, it is possible to make electricity without using magnets. Wnt (talk) 17:54, 12 June 2011 (UTC)

The Baghdad Battery is a likely hoax. Lodestones may have been created by lightning strikes in soil containing iron ore. Edison (talk) 00:43, 13 June 2011 (UTC)

wow, thanks. I haven't heard of lodestones before, very nice :) --helohe (talk) 19:26, 12 June 2011 (UTC)

Interchangeability of USB wall chargers

I have a Sandisk Sansa Clip+ which is charged over USB (mini-B) and doesn't come with a wall charger, and I have a Motorola mini-USB cell phone wall charger, model FMP5185B, input 100–240V, 50/60Hz, output 5.0V, 550mA. Can I safely charge the one with the other? This thread is full of people saying it's okay, but this thread makes me worry. If there's any doubt, I'd rather not do it. -- BenRG (talk) 19:02, 12 June 2011 (UTC)

I'm not an expert but those wall chargers just emulate a normal usb cable from a computer so they should be using the same specification. The USB article lists normal usb power as "500–900 mA @ 5 V" which is the same as yours AvrillirvA (talk) 22:41, 12 June 2011 (UTC)

As I remarked recently on the RDC, all wall AC/DC adapters for mobile phones or heck nearly everything I've seen in the past 4+ years or so have been SMPSs. There may be some traditional linear transformer only wall AC/DC adapters with fullsize/mini/micro USB sockets or plugs but I doubt they we were ever common. Definitely all image search results for the motorola razr v3 adapter I find seem to be SMPSs. Of course since you actually have the adapter you can probably tell by the size and weight. However since the specs for your device say it supports 100–240V, it obviously has some regulation and is almost definitely a SMPS.

Also if you overcharge li-ion batteries they may explode fairly violently. Since manufacturers find this undesirable, they tend to design devices to avoid this. If you supply too high a voltage you may kill the device or charging circuitry. You're far less likely to overcharge the batteries. (Li-ion batteries also should generally be charged with a CC-CV charging profile. And the CV stage should generally be 4.2V regulated to with +/- 0.05V or better [10], there are specialised chips for this which may be what most manufacturers use but in any case this isn't something you handle by simply dropping the voltage of a 5V USB supply where +/- 5% is within regulation.)

Finally if you're drawing a higher current then the AC adapter can supply and there's no safety or fuse, you risk damaging the adapter, perhaps even causing a fire. Alternatively the voltage may drop too low (as the poster sugggested) and the device and charging circuitry won't be able to function correctly. There's a slight chance this may result in an incomplete charge, more likely you're just get random problems or the device/charging won't work at all.

In other words, nearly all the claims of the person in the second link are questionable.

BTW the EU has defined a Common External Power Supply. The Open Mobile Terminal Platform agreed to something similar. While your devices appear to predate that (since microUSB not miniUSB is the agreed standard) the idea is that you can use any charger.

Nil Einne (talk) 01:42, 13 June 2011 (UTC)

The power supply is small and light, not one of the big-and-heavy wall warts that were all the rage a decade ago, and I assume the Clip+ won't try to draw more than 500mA since that's all that USB guarantees, so I guess it's safe. I may still be too scared to try it, though. Thanks for the replies -- BenRG (talk) 06:36, 15 June 2011 (UTC)

Identifying small trilobites in Ordovician-age rock

Hi. I have some samples of Ordovician fossiliferous limestone. Some of those samples may contain fragments of trilobites, and I would like to identify them using specific features if possible. How do I identify the body fragments and distinguish them from other fossils, a partial list being bryozoans, gastropods, porifera, crinoids, brachiopods, and possibly others such as cephalopods and ostracods? Thanks. ~AH1 ^(discuss!) 20:17, 12 June 2011 (UTC)

Take a course in invertebrate zoology. Look for a continuos closed chitinous exoskeleton. Contact Robert Loveland of Rutgers University. Look for a segmented body and jointed limbs. Publish any pictures yo have and ask for comments if you are not sure. μηδείς (talk) 22:35, 12 June 2011 (UTC)

Pain & C-Fibers

I'm having a hard time tracking down an answer for what I was assuming was a straightforward empirical question: People argue that pain is possible even without c-fiber stimulation. But are there cases on record of normal, psychologically healthy adults who complain of pains that cannot be correlated with any kind of c-fiber activity? I.e., cases where an otherwise normal (I say that to sort of weakly rule "hypochondriacs" or, generally, people we have reason to doubt make veracious claims about their physiological states) adults sought medical help for pains which subsequently could not be grounded to any neurological goings-on.

Thanks! — Preceding unsigned comment added by 99.32.190.71 (talk) 20:20, 12 June 2011 (UTC)

I think phantom pain, and neuropathic pain of the "central" type, are pretty clear examples. C-fibers contribute to phantom pain in some instances, but some of the worst pain comes in people for whom all the relevant C-fibers appear to have degenerated. Looie496 (talk) 00:31, 13 June 2011 (UTC)

I would say it's true, since a person is able to experience pain in a dream. Plasmic Physics (talk) 03:51, 13 June 2011 (UTC)

Really? In all my life I never have. Heck, when I had the gout I would sometimes avoid moving my legs for up to an hour after waking, simply to keep the sleep paralysis going so I wouldn't feel the pain. Wnt (talk) 05:14, 13 June 2011 (UTC)

It is actually a quite remarkable fact that people are not able to experience pain in dreams. You can dream that your legs are blown off by an explosion, but you will not feel any pain when it happens. Other forms of distress are common, such as a feeling of suffocation or overheating, or a need to urinate. Looie496 (talk) 06:38, 13 June 2011 (UTC)

That is wrong. I've felt pain in dreams, and I can't find any sources stating it's impossible to feel pain a dream. I understand that sometimes something which would cause pain in real life doesn't in a dream or the perception of pain is different in dreams, but that is very different from never being able to experience pain in dreams 82.43.90.27 (talk) 21:04, 13 June 2011 (UTC)

I speak from personal experience, I had my hand chewed on and I can tell you: it wasn't as painful as you'd think, but still very much (like a painfully firm handshake). Coincidentally, I realised that I was infact dreaming. As soon as I did, I managed to rationalise the pain away. You know what, dreaming is so much more fun when you know you are dreaming. The annoying thing is that as soon as you know that you are dreaming, one of two things can happen: either, your brain sabotages you and you wake up, or your state of mind lets you forget very easily that you are dreaming. Plasmic Physics (talk) 08:02, 13 June 2011 (UTC)

Rarely, I am able to maintain a rational state of mind to allow me to create my own dream. Plasmic Physics (talk) 08:08, 13 June 2011 (UTC)

I have to say that pain in a dream rarely matches the type, or severity of the injury, it hasn't so far for me. Plasmic Physics (talk) 08:43, 13 June 2011 (UTC)

I don't know about others but I can occassionally feel pain in dreams. I once went to sleep with a headache, and was aware of the headache in my dream. I then took some asprin in my dream and the headache went away. And it stayed away until I woke up whereupone the headache returned. This has also convinced me personally that the placebo effect is a real thing. Googlemeister (talk) 17:27, 13 June 2011 (UTC)

Here is another example: I dreamt I was on fire, you'd think it was agonising, but it wasn't, it felt like a bad sun burn. This makes me think that pain in dreams are sourced from personal experience, you can't feel a pain in a dream that you havn't experienced before in the real world. i.e. if you've never had a broken arm, you can't experience the pain of a broken arm, your brain just gives you the next closest pain that you have experienced.

Memory plays a central role in pain synthesis in dreams. I would really like to have a citation for 82.43.90.27's refutal. Plasmic Physics (talk) 23:23, 13 June 2011 (UTC)

I based my statement on an assertion in one of Alan Hobson's books, together with the fact that I myself don't recall ever experiencing pain in a dream. However, a check of the literature shows that the consensus view on this question has changed: more recent studies such as PMID 7690981 and this paper report that although pain in dreams is rare, it does occur. Looie496 (talk) 23:39, 13 June 2011 (UTC)

I can possible explain why I have the ability, I have Asperger's - I am not an ideal test subject. My brain opperates differently to those that do not have Asperger's. Plasmic Physics (talk) 00:18, 14 June 2011 (UTC)

Oh, it actually was scientific consensus at some point that people didn't feel pain in dreams? I remember reading it in a pop-sci book as a young child, and discussing it with my older sister because we had both felt pain in our dreams: not awful pain, but pain. We briefly considered that maybe we simply dreamt that we had felt pain, without actually feeling pain, but (given that on one occasion she had been awoken by the shock of the pain) this seemed unlikely, and we decided that once we started defining pain as something other than 'a painful sensation', we were headed for trouble. So we assumed the book was simply wrong, as so many children's factbooks are. I'm not sure if I'm reassured or disturbed that this was actually an accepted theory quite recently: did nobody carry out even a broad survey? It's like the 'tongue maps' all over again. 86.164.30.215 (talk) 21:48, 14 June 2011 (UTC)

Fat

Why can body make fat easy from cabohyrat but you can eat lot of fat but no get fat? — Preceding unsigned comment added by 92.25.100.10 (talk) 20:49, 12 June 2011 (UTC)

That's not true. You get fat if you eat more calories than you burn in exercise, whether those calories come from carbohydrates or from fat. The moral is: eat, but don't eat too much. Simple, but not always simple to follow.Itsmejudith (talk) 21:26, 12 June 2011 (UTC)

(ec) Because the body also uses fat as a source of energy. (See Citric acid cycle for extensive details. Well, it's a bit complicated on the biochemistry level.) Fat is only synthesized from carbohydrates because fat has a higher energy density and thus can be stored more easily. 5BYv8cUJ (talk) 21:36, 12 June 2011 (UTC)

June 13

what are the health effects of chronic *low* blood sugar? (if there is such a thing)

Please note that nothing in this question is a request for medical advice, anyone who requires medical advice should seek the advice of a qualified doctor, rather than anonymous unqualified respondents from an online reference desk, who are liable to be completely mistaken in their understanding and assume no responsibility for anyone who kills or injures themselves or others by mistaking anything here as medical advice or relating to it in any way.

This is not a request for medical advice -- indeed, it does not relate to me or anyone I know -- but I was wondering what, if anything, the health effects of chronic *low* blood sugar are? For example if a diabetic using insulin were to be mistaken in the amounts of insulin given, but not to the point of an acute hypoglycemic attack, but, instead, consistently low (rather than high) blood sugars, so that it remains chronically below that of a healthy person by a significant amount, but not enough to cause an acute hypoglycemic ris... then is what are the health effects? thanks.

to give you an idea of my impression, it seems that unlike moderately high blood sugar, moderately low blood sugar is not something with chronic health effects - it can be an acute episode, but nothing chronic. This is my impression, since I'm having trouble digging anything up -- that's why I've come to the ref desk :)

Note: this is a question about blood sugar not blood pressure, which is a different question.

also please note that nothing in this question should be construed as requesting medical advice in any way. — Preceding unsigned comment added by 188.28.37.179 (talk) 01:01, 13 June 2011 (UTC)

An extended, boring, hunger craving- filled, Calorie restriction life-span. μηδείς (talk) 01:13, 13 June 2011 (UTC)

See Hypoglycemia (low blood sugar) and Hyperglycemia (high blood sugar) for complete explanations. Both conditions can be chronic or acute; both are serious conditions if uncontrolled. Bielle (talk) 01:23, 13 June 2011 (UTC)

(EC)An answer more responsive to the question would cite the article Hypoglycemia, which says that low blood sugar produces the symptoms of shakiness, anxiety, nervousness, palpitations, tachycardia, sweating, pallor, coldness, numbness, hunger, nausea, vomiting, abdominal discomfort, headache, abnormal mentation, impaired judgment, fatigue, confusion, and a host of other symptoms. It can also be fatal, per the article. Edison (talk) 01:31, 13 June 2011 (UTC)

Did you need to chastise us, Edison? Does it help the OP in some way to have done so? Bielle (talk) 01:38, 13 June 2011 (UTC)

Note the (EC). The preceding response by Medeis was the one I considered less than ideally responsive to the question. You and I cited both cited Hypoglycemia. Chronic low blood sugar would not be much fun, with the symptoms listed in the article cited, as well as anger and depression listed as symptoms in some of the "alternative medicine" books about the claimed widespread hypoglycemia. Chronically reduced mental efficiency might be a problem. For a diabetic on insulin or oral sugar lowering meds, there would be the constant fear that it is about to drop from a low 70 mg/dL to a disastrous 40 mg/dL. It is rare for blood sugar to be really stable in a diabetic. There would be little margin for error between "low" and "so low as to cause convulsions and unconsciousness." "Chronic hypoglycemia" was a popular pseudodisease or fad disease of the 1970's and 1980's, [11] among gluconormal nondiabetic hypochondriacs, with popular books, [12] written about how to treat it. There are many true believers in chronic hypoglycemia as a cause of a variety of ailments not widely supported by the medical establishment, who claim that 10 to 25% of the general population suffers from hypoglycemia. Drugstores sell inexpensive glucose meters which can readily tell whether blood sugar is normal, low or high. Edison (talk) 03:12, 13 June 2011 (UTC)

I am sorry for having assumed that if the person were suffering from chronic low blood sugar he hadn't just died of starvation or accute hypoglycemic shock. The question seemed to imply voluntary dieting. Life extension by such means is a common topic of discussion. μηδείς (talk) 01:41, 13 June 2011 (UTC)

There was no implication in the question that hypoglycemia resulted from voluntary dieting. Edison (talk) 03:12, 13 June 2011 (UTC)

Let's hear from the poster, who did, I believe, use the word chronic. There certainly was no question of the acute effects which you referred to, while extreme caloric restriction, which I referred to, is posited as a method of life extension. Or did I get that wrong too? μηδείς (talk) 03:38, 13 June 2011 (UTC)

Any kind of suspected blood sugar imbalance, and any kind of dieting, should be dealt with by consulting a doctor. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:13, 13 June 2011 (UTC)

Chronic hypoglycemia actually causes someone (well, at least some rat) to increase the amount of sugar transport past the blood-brain barrier. Thus some of the effects of acute hypoglycemia don't apply as the person's system adapts. Likewise, glucose transport decreases in diabetes, perhaps a bad thing for diabetics when insulin dose is too high.^[13] Wnt (talk) 03:30, 13 June 2011 (UTC)

you guys don't really get the question. (op here). I mean, if you read about "diabetes complications" you can see that if someone has a blood sugar of 8 for 20 years (instead of the normal 5.5), or on the other scale 144 instead of the normal 100, then they can get complications. That is just slightly above normal. So, what about consistently slightly below normal? Like 4 (72 on the other scale) consistently day in day out for years? Are there complications that develop over time from chronic slightly below average blood sugar? (Note: all you guys have said about headache and vomiting and passing out etc are an acute attack of way lower blood sugar. Not my question). Thanks, and sorry I might not have been the clearest possible in originally asking. Nothing here relates to medical advice in any way, this is just more of a science quesiton. --188.28.126.160 (talk) 12:20, 13 June 2011 (UTC)

The article Hypoglycemia does "get the question, and answers it. Chronically low blood sugar has a host of possible symptoms that range widely both from person to person, and for any given person. Here, for example, from the linked article (boldface mine):

Determining the presence of both parts of this definition is not always straightforward, as hypoglycemic symptoms and effects are vague and can be produced by other conditions; people with recurrently low glucose levels can lose their threshold symptoms so that severe neuroglycopenic impairment can occur without much warning, and many measurement methods (especially glucose meters) are imprecise at low levels.

Reading the article will help you understand why a simple list of chronic symptoms is not going to be very accurate, although the list of possible symptoms and consequent damage is there. Bielle (talk) 17:09, 13 June 2011 (UTC)

Bed Bugs

I don't understand why people freak out about bed bugs. They are much more benign than other blood sucking insects, such as mosquitoes and ticks (for instance, they have not been proven to transmit diseases, and only a small percentage of people actually have a noticeable skin reaction to their bites. Most aren't even aware of it.). We get bitten by other insects all the time. So why all the fuss about bed bugs? Thanks. Quinn ^{❀ BEAUTIFUL DAY} 03:30, 13 June 2011 (UTC)

People are generally unpleased to be eaten by things, even if they are only being eaten in small bits at a time. There's a general revulsion against this, which is a Good Thing, since many other blood-sucking insects and other such parasites are known to transmit real disease. That bed bugs are comparatively less disease carrying isn't necessarily a factor in the level of revulsion people feel viscerally to being eaten. It's not an intellectual response. Furthermore, while bed bugs are pretty low on the "disease carrying vermin" ladder, the presence of any vermin is usually an indication of general uncleanliness; apartment buildings with bed bugs infestations can also have other pests (fleas, rats, etc.) which are not always so benign. Even if not true in every case, the presence of vermin of any sort is generally met with revulsion, for reasons described above. --Jayron32 05:22, 13 June 2011 (UTC)

Unlike mosquitoes or ticks, bed bugs infest homes, and particularly mattresses. Bed bug infestations are easily spread, and can be difficult to eradicate. Rckrone (talk) 05:30, 13 June 2011 (UTC)

Bed bugs are like head lice, not terribly dangerous, but very paranoia inducing. HiLo48 (talk) 06:03, 13 June 2011 (UTC)

I appreciate the answers, but I would point out that bed bugs have absolutely nothing to do with "un-cleanliness:". Bed bugs are generally brought in by the last person you allowed to sleep in your bed. Whether in luggage or other such transmitter.Quinn ^{❀ BEAUTIFUL DAY} 06:27, 13 June 2011 (UTC)

Inviting unclean people to sleep in your bed isn't itself a risky behavior? How is this different from inviting someone with fleas from sleeping in your bed? --Jayron32 17:49, 13 June 2011 (UTC)

Not terribly dangerous but they can be very irritating [14] on a whole lot of levels. I'm not sure people are paranoid about them; I think they are anxious which is rather different. Richard Avery (talk) 06:27, 13 June 2011 (UTC)

There is also what might be called the tautological response — people are disgusted by bedbugs because other people are disgusted by bedbugs. That is, it doesn't matter what I think, if all my friends will find me disgusting. Or, more to the point, if my property values are going to be affected, and so on. --Mr.98 (talk) 10:10, 13 June 2011 (UTC)

I'll also mention that many people are easily disturbed by bedbug behaviors, e.g. Traumatic_insemination. Granted, this has nothing to do with the risk/dangers they pose, but who said disgust was rational? SemanticMantis (talk) 13:32, 13 June 2011 (UTC)

Interesting premise but my guess is few people are sufficiently aware of such behaviours to be disgusted by them. Nil Einne (talk) 02:57, 14 June 2011 (UTC)

A sterile home were there are none of the insects that you find outdoors in Nature is a paradise for specialized bugs adapted to live in the home environment. Count Iblis (talk) 18:03, 13 June 2011 (UTC)

I'll take exception to your "small percentage of people". Our article on bed bug infestation puts the fraction of people with no visible skin response at between 20% and 70%. While that's a pretty broad range, if we assume that the non-responding fraction really is 70% (the 'best' case) then it's still better than even odds that at least one member of a two-person household will feel the bite. It turns out that it only takes one person waking up every day covered in spots to declare that the bugs are a 'problem' for the entire household.

The infestation article (and the main bed bug article, as well) talk about some other health and cosmetic issues. Rolling over on blood-engorged bed bugs leaves unsightly bloodstains on one's sheets and body. Bed bugs suck significantly more blood than mosquitoes; a full meal is on the order of 1 mL. While that's not a large amount by itself, ten bites per night for eight weeks is 560 mL of blood. That's as much as one donates when giving blood, at about the same frequency; severe or chronic infestation can push some people over into anemia. Some people also become sensitized to the bites through long exposure.

Finally, since transmission is relatively easy – and eradication can be rather difficult – they're the bane of multiple-unit dwellings. If one resident has them, eventually the bugs spread to everyone. Unless everyone treats them simultaneously, they'll tend to return and reinfest. Even if most people aren't bothered, some will suffer quite acutely. TenOfAllTrades(talk) 13:39, 14 June 2011 (UTC)

Need help identifying this ladybird-lookalike

Hi,

Was in my garden two days ago and noticed this colorful critter crawling around on an asparagus plant.

• 
• 
• 

Colors and spots look like a ladybird. I am mostly familiar with the common seven-spotted ladybird, but I know there are other species of ladybirds. But this isn't a ladybird, is it? It is a bug trying to look like one, isn't it? The shape of the body just does not fit well with a ladybird. Any help on the id would be appreciated. Thanks,

--Slaunger (talk) 05:41, 13 June 2011 (UTC)

Hi that is a common asparagus beetle :) — Preceding unsigned comment added by 109.224.25.11 (talk) 06:15, 13 June 2011 (UTC)

Forgot to inform about the location: Viborg, Denmark. --Slaunger (talk) 06:15, 13 June 2011 (UTC)

Ok sorry about that link does not work; how ever if you type orange and black bug uk into google images you will find it there as a asparagus beetle.

Thanks for the hint. But I do not think it is a common asparagus beetle, rather a spotted asparagus beetle, Crioceris duodecimpunctata. --Slaunger (talk) 06:29, 13 June 2011 (UTC)

Well spotted!--Shantavira|^{feed me} 06:37, 13 June 2011 (UTC)

Hahaha :-) --Slaunger (talk) 07:17, 13 June 2011 (UTC)

Recent Volcanic Eruptions

With the recent icelandic eruptions and now the chilean eruption pushing vast amounts of ash into the atmosphere, would this effect global temp or would this be an insignificant event? What scale of eruption at various points on the planet would significantly effect global temp? which could by all tense and purposes reverse global warming? — Preceding unsigned comment added by 109.224.25.11 (talk) 05:43, 13 June 2011 (UTC)

Pinatubo in 1991 had a significant effect, but it was on the same scale as natural variations on top of the warming trend

These are both fairly insignificant events on the global scale. In order to see significant global cooling you need to inject a vast amount of ash and sulfates into the stratosphere, which requires an extremely energetic eruption. The current eruptions of Puyehue in Chile and Grímsvötn in Iceland are 3 and 4 on the Volcanic Explosivity Index (VEI) respectively. To give you a sense of the scales involved: Mount Pinatubo's 1991 eruption had the effect of lowering the global temperature by about 0.4 °C; this about the same as the amount of warming seen in the past 20 years (see image). However, Pinatubo's eruption was a 6 on the VEI (i.e. about 100 times more material erupted than Grímsvötn and about 1000 times more material erupted than ), had an ash column up to 21 kilometres (13 mi) high, and occurred near the equator which facilitated the spread of cooling stratospheric aerosols across the entire globe. Even with this extreme event, its cooling effect only lasted about 2 years. The current eruptions have only had ash clouds up to 10 and 12 km respectively, which is just barely into the stratosphere (if it is at all; the height of the stratosphere actually changes from day to day with the weather).

Also, your idea that a volcanic eruption could somehow "reverse" global warming is quite unlikely; the residence times of sulfates and ash in the atmosphere are on the order of a few years, while CO₂ has a residence time of about 400 years. Volcanoes also emit large amounts of carbon dioxide in addition to ash and sulfates, so I imagine in the long run the overall effect of a large volcanic eruption would be a net warming.-RunningOnBrains^(talk) 06:25, 13 June 2011 (UTC)

I realize upon re-reading that I was unclear on a few things. Volcanic aerosols (mainly volcanic ash and sulfur dioxide) suspended in the atmosphere reflect sunlight back into space, thus if you inject a large amount of volcanic aerosols into the stratosphere you can lower the amount of sunlight that reaches the earth by several percent, leading to cooler temperatures. The reason you need the eruption to reach into the stratosphere is that there is very little in the way of weather-related processes such as rain which quickly remove volcanic aerosols from the atmosphere. Ash and sulfates in the troposphere will likely be washed out on the order of weeks; not nearly long enough to cause significant cooling.-RunningOnBrains^(talk) 06:31, 13 June 2011 (UTC)

The volcanic winter article might be of interest, although it could do with some expansion. CS Miller (talk) 08:42, 13 June 2011 (UTC)

Being pedantic, but sulfur dioxide is a gas. It gets oxidized to a sulfate. -Atmoz (talk) 17:18, 15 June 2011 (UTC)

Note that the Mount Pinatubo eruption began in the early summer, while the Chilean eruption is occurring in early winter. μηδείς (talk) 18:56, 13 June 2011 (UTC)

I'm not sure that really matters, except that the tropopause (the bottom of the stratosphere) is typically a bit lower in the extratropical winter, though still around 10 km.-RunningOnBrains^(talk) 20:44, 13 June 2011 (UTC)

It matters because there's a lot more sunlight to be blocked during summer, μηδείς (talk) 01:25, 14 June 2011 (UTC)

Well, the sun-reflecting effect of stratospheric aerosols is over the course of about two years, so it could have some effect, but the effects will be spanning several seasons anyway; thus, I doubt there will be much difference what season the eruption occurs in. However, a big difference here is the ash will be mostly confined to the hemisphere the eruption occurs in due to stratospheric wind patterns, unless, of course, like Pinatubo, the eruption occurs near the equator. Tropospheric volcanic aerosols are mostly washed out of the atmosphere by rain and other processes in a matter of days, so it is really only these long-lived stratospheric aerosols that matter. -RunningOnBrains^(talk) 02:54, 14 June 2011 (UTC)

Yes, it's highly unlikely the the strongest sun blocking effects would actually occur during the time of the eruption rather than six to twelve (and eighteen to twenty-four) months after.

And what sort of magical numbers wizard could figure out what the chances are that the period starting one year to eigtheen months later will actually be during the same season as the first six months? What are we, fortune tellers? μηδείς (talk) 03:07, 14 June 2011 (UTC)

I was referring to the fact that the effect will last for more than one year, thus the dimming effect would be integrated over all seasons. Sure, maybe we'll have one more winter than summer, but unless we are talking arctic circle latitudes, this effect should be negligible. Additionally, the ash will spread to much of the hemisphere, and possibly the globe, over this time, further diminishing the seasonal impact. I'm not saying it won't matter, I'm saying it probably won't make a significant difference.-RunningOnBrains^(talk) 22:32, 14 June 2011 (UTC)

Any effect that that lasts more than a year can be discounted, since after one year you are back to the same cycle of seasons. For example SUMMERWinterSUMMERWinter or the reverse. The same with the effect spreading over the entire hemisphere, since the entire hemisphere is in the same season at the same time. I cannot find a chart of seasonal insolation, but it is obvious from this temperature graph which can stand proxy for the effect at mid lattitudes that the effect is significant. Only if there is an extremely low rate of decrease in sun blocking from an eruption over many years or if there is a very fast mixing between the hemispheres will the seasonal effect be negligible. The Mount Pinatubo eruption caused a drop in temperature in the Northern hemisphere of about 1.0 degree F and about 0.4 degrees F in the Southern Hemisphere. This does not control for season, obviously, but it does show the significant hemispheric difference, and hence imply a seasonal effect. μηδείς (talk) 16:08, 15 June 2011 (UTC)

I've done a brief literature search and only one paper appears to address the seasonal effects thoroughly: The Volcanic Signal in Surface Temperature Observations (1994). I don't have time to read the whole paper right now, but they seem to indicate that there is a significant seasonal effect. So you may indeed be right; a summer eruption (especially early summer) seems to have a greater cooling impact, with some uncertainty due to a limited and noisy data set. In regards to the OP, however, the point is moot, since the current eruption plumes are not reaching significantly into the stratosphere. -RunningOnBrains^(talk) 02:58, 16 June 2011 (UTC)

Triplet carbenes

why are triplet carbenes normally sp² hybridised but become sp hybridised when bonded to oxygen ,nitrogen ,sulphur or halides ? Raky rough (talk) 12:05, 13 June 2011 (UTC)

Does Carbene#Structure_and_bonding help? --Jayron32 17:51, 13 June 2011 (UTC)

The Carbene#Structure_and_bonding section shows two diagrams for triplet carbene .[[15]] now i can't understand how the presence of electonegative elements can change sp² carbene to sp and in the process unhybridises one of the hybridised sp² orbitals Raky rough (talk) 15:26, 14 June 2011 (UTC)— Preceding unsigned comment added by Raky rough (talk • contribs) 15:24, 14 June 2011 (UTC)

Does the attached group you are considering affect just the geometry/hybridization of the triplet, or also the relative stability of the singlet vs triplet? The article says the latter, you seem to be asking about the former. DMacks (talk) 15:33, 14 June 2011 (UTC)

well yes i was asking about the former . i was thinking about the case of trifluoromethyl radical where the strong -I effect of three fluorine atoms change hybridisation from sp² to sp³ (hence s character of hybridised orbitals decreases). but the effect of the electronegative groups in case of triplet carbene is opposite (s character of hybridised orbitals increases) which puzzles me.Raky rough (talk) 16:52, 14 June 2011 (UTC)

pressing question

why is it that if you unplug a fridge for a while, even if you clean it fastidiously, it will smell really musky. no matter how long you air it out. but lo, when you plug it back in again, as soon as it finishes cooling again, that smell is gone! why does cold desmellify in this mysterious manner. thanks for any scientific insight you might have on this question. --188.28.126.160 (talk) 12:50, 13 June 2011 (UTC)

I've tracked down the musty smell in my refrigerator to the condenser and drain pan. So, cleaning the inside of the fridge won't help with that. A long time ago, when I lived in an apartment, my fridge really stank. That is how I learned about the drain pan because I tracked it down and found that the drain pan in that fridge was full of blood. -- kainaw™ 13:08, 13 June 2011 (UTC)

(edit conflict)Possibly, because there exists bacteria on the inside surface of your fridge that isn't removed by anything short of bleach. Low temperatures negatively impacts cellular metabolic rates, explaining why you only detect a smell when the fridge is above normal operating temperature. Bacteria give off gases as a waste product of metabolism, the lower the temperature, the lower the concentration in the air. Plasmic Physics (talk) 13:16, 13 June 2011 (UTC)

That's a very good explanation. Almost too good. 188.28.126.160 (talk) 13:52, 13 June 2011 (UTC)

And that should be testable by storing said unplugged refrigerator in consistently cold conditions, say outside in locations where temperatures stay around freezing for several months at a time. Surely someone around here's done this? --jjron (talk) 14:28, 13 June 2011 (UTC)

It's not just a metabolic effect. The vapor pressure of the smelly compounds that produce the odor you're detecting also varies with temperature. Higher temperatures mean that the maximum concentration of stinky stuff in the air is also higher; higher temperatures will also tend to drive faster evaporation of these nasties. Your nose can detect some odiferous compounds at concentrations of parts per billion or even less, so it takes a very small reservoir of these compounds in the fridge (tucked into crevices, hidden in door seals, even just adsorbed on the plastic surfaces) to continue to release odor for a very long time. TenOfAllTrades(talk) 15:10, 13 June 2011 (UTC)

I knew it.. 188.28.126.160 (talk) 19:18, 13 June 2011 (UTC)

Strontium ferrite vs. barium ferrite

Which is more likely to be found in common household magnets? Or are they a mixture of both? --Chemicalinterest (talk) 16:11, 13 June 2011 (UTC)

I don't know but you could try an experiment, construct a rudamentary spectroscope using a prism, a gloss black backdrop, a candle, and a piece of cardboard with a narrow slit cut into it. Prepare a concentrated solution, by dissolving a few tens of miligrams into 5 ml of hydrochloric acid. Arrange the backdrop, prism and cardboard in such a way so that light from the lit candle is shining through the slit is reflected and refracted through the prism onto the backdrop. Once you have the experiment set up, dip a piece of iron wire in your solution. Hold the dipped end in the flame of the lit candle, and observe the spectrum on the backdrop, this works easier in the dark. Compare this spectrum to those of strontium and barium, I'm sure you know what to do with those. Plasmic Physics (talk) 14:53, 15 June 2011 (UTC)

body

what are the harmful effects of masturbating? — Preceding unsigned comment added by 117.224.212.237 (talk) 16:57, 13 June 2011 (UTC)

Do you consider sticky fingers harmful? Googlemeister (talk) 17:17, 13 June 2011 (UTC)

Chafing.-RunningOnBrains^(talk) 17:19, 13 June 2011 (UTC)

I think Jocelyn Elders answered this question accurately. Wnt (talk) 17:40, 13 June 2011 (UTC)

Lube. -Atmoz (talk) 17:09, 15 June 2011 (UTC)

Depending on your social environment, there are taboos in some societies about masturbation, so you could suffer socially. There are lots of different cultures in the world, each with their own opinions on these things, and depending on which culture you find yourself in, you may experience various levels of social consequences from masturbation. --Jayron32 17:46, 13 June 2011 (UTC)

There are no known harmful health effects from masturbating. thx1138 (talk) 18:13, 13 June 2011 (UTC)

WebMD has some funny stuff up, that frequent masturbation is correlated with an increased risk of prostate cancer in men in their 20s and 30s, but a decreased risk in men in their 50s.^[16] Wnt (talk) 18:23, 13 June 2011 (UTC)

Yes, but in that article the researchers say that the frequency only indicates the sex drive, which in turn is a function of the level of hormones. A man's prostate can't tell whether orgasms come from masturbation or intercourse - probably, how would it? Itsmejudith (talk) 21:23, 13 June 2011 (UTC)

There are also these experts: She-Bop Dancing with Myself

Portnoy's Complaint _does_ highlight one disadvantage - the real thing is rather disappointing and difficult in comparison. I recall a story on Fark [17] some years ago (not the most reliable of sources, of course) about Japanese men who suffer from this problem, although I'm sure it's applicable across the world. Tevildo (talk) 20:20, 13 June 2011 (UTC)

Note to self: If I ever get engaged to marry, I've got to refrain from jacking off from that time onward. However, I've got to point out that even if this is true, 45 times a year translates to roughly once every 8 nights, which is not too bad -- in fact, AFAIK the world average for married couples is "only" once every 7 nights. 67.169.177.176 (talk) 23:22, 13 June 2011 (UTC)

Hmm the Durex surveys says 103 times a year is the average [18] [19]. This includes all non-virgins surveyed, married or not. However my impression is despite some misconceptions, most surveys show married people usually have sex more often then unmarried. Of course surveys of that nature usually have a big question mark due to the likelihood of people lying. Also the 2007 one at least, uses the internet for many countries and which would likely lead to a bias towards those who are richer and may have more free time (and more likely to be living together if married or in a relationship).

But the Durex surveys are the ones that get reported, if others exist that have tried to study the frequency of sex over a range of countries I haven't seen them (not something I've really looked for). BTW an interesting thing I noticed, while frequency of sex has a strong impact on sexual satisfaction (well that's what the 2007 survey said), some countries like Nigeria have relatively high satisfaction despite relatively low frequency of sex.

To bring this mildy back on topic, it's worth remembering masturbation is not solely a solo practice. In fact our article says

Contrary to conventional wisdom, several studies actually reveal a positive correlation between the frequency of masturbation and the frequency of intercourse. One study reported a significantly higher rate of masturbation in gay men and women who were in a relationship.

Given that, while masturbation is safer then many other practices; if you do masturbate with a partner you should use safer sex practices and birth control where necessary. If you don't while arguably not a harmful effect of masturbation per se, there's a slight chance this could lead to pregnancy or a STI.

Nil Einne (talk) 04:40, 14 June 2011 (UTC)

103 times a year? That's twice a week, which is very good indeed! 67.169.177.176 (talk) 21:42, 14 June 2011 (UTC)

Normalizing Associated Legendre Polynomials to get Spherical Harmonics

Hi all. I've been working on this problem for like weeks, and I can't seem to figure it out. I'm trying to normalize Associated Legendre polynomials to turn them into Spherical harmonics. The integral comes out to:

$\int _{-1}^{1}P_{\ell _{1}}^{m}(x)P_{\ell _{2}}^{m}(x)dx={\frac {1}{A^{2}}}$

where $A$ is the normalization constant. $A$ can be found in Spherical harmonics#Orthogonality and normalization. I know that it involves integrating by parts $\ell +m$ times, and that the boundary terms vanish in each case, but I'm not sure why they vanish. Can anyone point me to a (very detailed) discussion of how to actually do the integral, or maybe a better way than by parts? Thanks!--Dudemanfellabra (talk) 21:01, 13 June 2011 (UTC)

This question would probably be better on the Maths desk. Tevildo (talk) 23:57, 13 June 2011 (UTC)

This problem comes up while determining the Hydrogen wavefunction using the Schrödinger equation, so it's kind of physics and math. As such, when I asked here, I also started a thread at the Math desk as well. Just in case a physicist stops by here, I wanted them to see it.--Dudemanfellabra (talk) 02:34, 14 June 2011 (UTC)

It may be easier to use the definition of the states |l,m>, so you say that you get |l,m> by applying L^(-) l-m times to |l,l> And then you compare this |l,m> in the angular basis with the definition of P_l^m. Count Iblis (talk) 15:24, 14 June 2011 (UTC)

Cleaning styrofoam

I have a styrofoam cooler that I use all the time, just for ice and soda so it really doesn't get funky because no foodstuffs are in it ever. Anyway, after a lot of use, the inside is a bit yellowed and has a slightly musty odor, so I thought I'd put some water in it with some bleach (about one-half cup bleach to a half-gallon of water is what I usually use for such applications, I guess that's a 1:16 mixture). This works great for mildew and the like. However, my friend told me that bleach and styrofoam are a bad mix, that they give off deadly fumes. Of course, I am now terrified to do this, especially indoors. Is there validity to this? I guess I should be very precise: My household bleach doesn't say what's in it but does say that it "CAUTION, CORROSIVE! contains sodium hydrochlorite". The styrofoam does not say exactly what it is but it is marked with a triangular recycle symbol with a 5 inside, and says just below that, "PS"--maybe PolyStyrene? Note that there's nothing on the bleach label's caution list to single out styrofoam, but of course it can't list every stupid thing anyone might try, so I'm not putting any store by that. Oh, and if anyone knows of an alternative method that works well with styrofoam, of course I'm all ears.--108.54.17.250 (talk) 23:03, 13 June 2011 (UTC)

My friend says I'm inhaling deadly fumes. Reference desk, can I continue or is he right? --188.28.126.160 (talk) 23:15, 13 June 2011 (UTC)

Are you the same identity as the the above IP? If you are not, what are the fumes originating from? Plasmic Physics (talk) 23:26, 13 June 2011 (UTC)

Polystyrene is pretty chemically inert (like most other plastics), so I don't think it will react with chlorine or sodium hypochlorite (at least, in the absence of a catalyst such as aluminum chloride), much less in a way that releases deadly fumes. At worst the plastic might become chlorinated and further discolored, but even this is rather unlikely. You don't need to worry about poisoning yourself. As for an alternative method: I don't have a clue. 67.169.177.176 (talk) 23:33, 13 June 2011 (UTC)

Well, whatever you do, don't clean it with acetone. Plasmic Physics (talk) 00:42, 14 June 2011 (UTC)

Bleach fumes are caustic, but I don't think the Styrofoam contributes a bit. I use bleach on them outside, so the fumes can dissipate. I just cleaned one that way last week, as a matter of fact. Make sure it's somewhere kids or pets won't get at the bleach, though, if you leave it out to soak in bleach, as I do. StuRat (talk) 00:50, 14 June 2011 (UTC)

Dear God. Styrofoam coolers are like $5.00 or so. If its so nasty it can't be cleaned, recycle the old cooler and buy a new one. This is a penny-wise-and-pound-foolish issue on two regards: 1) You are likely spending more money and effort on cleaning the cooler than the cost would be to just buy a new one 2) Harsh cleaning chemicals have a greater environmental cost than recycling an old cooler would, or probably even just throwing it away. You are seriously better off just buying a new one. If you can keep it for, say, 5 years, I don't think a dollar a year is too much of an investment for cold beer... --Jayron32 01:09, 14 June 2011 (UTC)

You seem to assume a cooler only needs cleaning once every 5 years. In my experience they need cleaning every time they are left closed up for a while. I get bleach for a dollar a gallon, so can do a lot of cleaning at that rate, before it would pay for a new cooler. And can you recycle Styrofoam ? The best I could manage was to reuse one as an (ugly) planter. StuRat (talk) 04:16, 14 June 2011 (UTC)

Of course you should clean it frequently, but at some point its important to know when to cut one's losses. When the cheap, disposable styrofoam cooler can't be cleaned by normal means and resists anything except exotic cleaning agents or requires an extensive committee discussion to arrive at a possible cleaning method, it's time to cut bait and start over. I'm quite a frugal person myself, and I quite support using items wisely, but even I have my limits; at some point you've just got to buckle down, and dip into those savings for that new styrofoam cooler... --Jayron32 04:25, 14 June 2011 (UTC)

You consider bleach to be exotic ? To me it's the most basic cleaning agent there is. :-) I doubt that it's as bad for the environment as detergents. Once fully diluted, the only harmful effect I could imagine is it making rivers and lakes less acidic, but that would take a massive quantity, and, due to acid rain, some movement in that direction might even be beneficial. StuRat (talk) 04:43, 14 June 2011 (UTC)

No, not really. I clean my cooler with it all the time... --Jayron32 04:44, 14 June 2011 (UTC)

Then I don't understand your previous posts. StuRat (talk) 04:47, 14 June 2011 (UTC)

Then we're both fooked, because I hoped that at least you could shed some light on them. I am quite baffled myself. --Jayron32 05:32, 14 June 2011 (UTC)

Diluted bleach solution shouldn't hurt the cooler, though depending on its precise composition you might get further yellowing. As Jayron says, you might consider the acquisition of a new cooler. Twenty bucks will get you one with a hard plastic shell and snug-fitting (possibly hinged) lid. They are better-insulated, so the beer stays cooler, longer. They're more durable and they won't chip off bits of unsightly styrofoam fluff if you bang them around a bit. (They'll also stay intact and closed if you pack them under all your luggage in the trunk of the car.) They have proper carrying handles, some have drain spigots to remove excess meltwater, and in a pinch you can sit on them. The interior hard plastic lining is non-porous, so it won't pick up odor quite as readily as exposed styrofoam, and can handle vigorous scrubbing. Yes, they're slightly heavier than the naked styrofoam coolers, but once you load them up with beer and ice the weight of the cooler is pretty negligible—and you may be glad of the carrying handle(s). For all coolers, you'll cut down a great deal on the mustiness if you leave them open (at least a little bit) after you clean them out, at least until the interior is completely dry. TenOfAllTrades(talk) 13:18, 14 June 2011 (UTC)

I have several large coolers of the type you describe; one I use a lot is a large cylindrical cooler, which I actually use when brining and/or marinating large roasts (whole turkeys, pork butts, stuff like that). Very convenient, and easy to drain off the brining fluid into the sink for disposal. I usually clean it with straight bleach afterwards, including cleaning out the drain spout with bleach and a small bottle brush. It probably cost me $30 dollars, and besides the meat preparation applications, I have used it for keeping beers and sodas cold as well. Much easier to work with than styrofoam... --Jayron32 15:11, 14 June 2011 (UTC)

(un-indent) "And can you recycle Styrofoam ?" -- Yes, polystyrene is fully recyclable, though for some reason (probably because it's so cheap and readily available) it doesn't get recycled to nearly the same extent as, say, PETE. There are AFAIK no particular technical obstacles to recycling styrofoam -- the only obstacles, if any, are economic and/or political.

"I doubt that it's as bad for the environment as detergents." -- Even if BOTH detergents AND chlorine bleach are used, the environmental impact from such small quantities of them will be negligible to nonexistent. All this "environmental impact" stuff has been deliberately hyped by Greenpeace and other likeminded eco-fascists eco-Luddites for at least the past thirty or forty years. 67.169.177.176 (talk) 21:55, 14 June 2011 (UTC)

I object to the malignment of Greenpeace (see article) as a fascist organization because Greenpeace does not accept funding from governments, corporations or political parties. Anionic detergents with branched alkyl groups were largely phased out in economically advanced societies because they are poorly biodegradable Bleach is toxic to fish and invertebrates, in confined spaces. Cuddlyable3 (talk) 12:26, 15 June 2011 (UTC)

While I agree on second thought that fascist in the strict sense of the word is not really applicable to Greenpeace (they are more accurately described as marxist, third-worldist and eco-Luddite), I must point out that accepting funding from governments, corporations or political parties is not a criteria for being considered a fascist organization (or any other kind) -- this depends SOLELY on the ideology being advocated. Linear alkylbenzylsulfonates that are in universal use as detergents today (as opposed to the obsolete branched ones you're talking about) are biodegradable and nontoxic -- to claim that all detergents are environmentally harmful when in fact this is a property only of a specific subset that is no longer used is fallacious at best and deliberately misleading for political purposes at worst. Fish and invertebrates don't naturally occur in "confined spaces" as the latter term is commonly understood. 67.169.177.176 (talk) 16:58, 15 June 2011 (UTC)

By the way, how can you be so sure that "Greenpeace does not accept funding from corporations or political parties"??? 67.169.177.176 (talk) 17:15, 15 June 2011 (UTC)

Like you I read Wikipedia that says: The global organization [Greenpeace] does not accept funding from governments, corporations or political parties, relying on more than 2.8 million individual supporters and foundation grants.. If you have verifiable information that should be in the article then add it. Cuddlyable3 (talk) 19:30, 15 June 2011 (UTC)

You can't always trust what Wikipedia says because it has a Marxist bias itself; as a matter of fact, I've been boycotting it for a year or so to protest against the actions of a certain commie scumbag re. the article Extermination through labor. In any case, you can't take documents written and published by the organization itself at face value without verifying this info with an independent, reliable, unsympathetic source (which Gilbert demonstrably isn't, as the title of her work clearly indicates her sympathies with the environmentalist movement). As for the matter of Greenpeace taking funding from corporations, there is the book The Hidden Face of Greenpeace by Olivier Vermont, where he alleges that Greenpeace has in fact been extorting racket money from various corporations. 67.169.177.176 (talk) 20:39, 15 June 2011 (UTC)

And even if in fact they do not take corporate money, that still doesn't prevent them from being third-worldist Luddites with Marxist political views -- this can be proved or disproved by their statements and actions alone. 67.169.177.176 (talk) 21:03, 15 June 2011 (UTC)

June 14

Does the planet Neptune contain water? If so, is it possible that there's a chance that maybe there's life?

Does the planet Neptune contain water? If so, is it possible that there's a chance that maybe there's life? If so, what kind of life? Neptunekh2 (talk) 03:23, 14 June 2011 (UTC)

Read Neptune. Basic summary: Neptune's mantle is mostly water and ammonia; one could call it an ocean many times the mass of Earth. It seems improbable that life as we know it could exist there, since temperatures are above 2000K, while DNA denatures at much lower temperatures.-RunningOnBrains^(talk) 03:28, 14 June 2011 (UTC)

The problem with this retort reply is carbon chauvinism, DNA is unique to Earth. The same problem is with water, water is a good solvent, but it doesn't mean all life requires it. Plasmic Physics (talk) 04:23, 14 June 2011 (UTC)

It is incivil to call an another editor's considered and informative reply to the OP a "retort", even when you can give supplementary information. Cuddlyable3 (talk) 07:32, 14 June 2011 (UTC)

For the record, I didn't consider it incivil. Also for the record, I am not a carbon chauvinist, but it is completely pointless to speculate on alternative forms of life, because science knows of no possibilities for non-carbon-and-liquid-water-based life as of now. I never say impossible unless I mean impossible, thus I said "improbable".

I don't think many complex molecules are stable at 2000K, carbon or not. StuRat (talk) 05:00, 14 June 2011 (UTC)

Because of its great distance from the Sun, Neptune's outer atmosphere is one of the coldest places in the Solar System, with temperatures at its cloud tops approaching −218 °C (55 K). Temperatures at the planet's centre are approximately 5,400 K (5,000 °C). Cuddlyable3 (talk) 07:38, 14 June 2011 (UTC)

Yes, but water is only in a useable liquid(ish) form in the mantle, where there are extremely high pressures and temperatures.-RunningOnBrains^(talk) 13:38, 14 June 2011 (UTC)

I think there are planets and moons in our solar system which are much better suited to life, carbon based or not. I would even go as far as saying that simple life forms are quite probable on Enceladus or Europa. --helohe (talk) 22:46, 14 June 2011 (UTC)

The problem is that the ambient conditions are either, incredibly high atm. pressure and very hot; or low atm. pressure and incredibly cold. There is no liquid water in Neptune, only crystal vapour and super critical water. Plasmic Physics (talk) 08:05, 14 June 2011 (UTC)

The answer to "is it possible...there's a chance..." regardless of what you fill in the blanks with is always "yes". There is always a very tiny possibility that there is a tiny chance that something may happen or exist. For example, it is possible that there is a chance that there is a flying spaghetti monster floating around the solar system. -- kainaw™ 12:57, 14 June 2011 (UTC)

Don't worry, the Invisible Pink Unicorn will trap him inside Russell's teapot. Cuddlyable3 (talk) 12:07, 15 June 2011 (UTC)

Mystery drug

This is a question about a drug I'm almost sure we have an article for, but I can't remember the exact name of it. The name is something like "Delidamide." It was pretty wide spread in the 50's and 60's for, what I think, was menstrual pains (or something along those lines.) It turned out to cause birth defects that caused shortened limbs among other things. JFK actually made a speech in which he encouraged women to stop using this drug and to "turn it in" to medical authorities. What was the name of this drug and any related articles about it on WP. Thanks! Quinn ^{❀ BEAUTIFUL DAY} 04:54, 14 June 2011 (UTC)

Thalidamide. StuRat (talk) 04:58, 14 June 2011 (UTC)

Actually, it is spelled "Thalidomide", but that's a minor issue. The drug itself was a sedative that was frequently prescribed for "morning sickness", which exacerbated the birth defect problem, for obvious reasons. The lesson of the drug shows up in organic chemistry classes when discussing the importance of knowing how stereochemistry works, in that one enantiomeric form of the compound cured morning sickness, and the other form gave your kids a third arm. the inability to give the correct answer at the reference desks. --Jayron32 05:05, 14 June 2011 (UTC)(edit: struck through wrong answer and corrected --Jayron32 12:58, 14 June 2011 (UTC))

3rd arm ? Not a side effect I'm aware of. StuRat (talk) 05:07, 14 June 2011 (UTC)

See Phocomelia#Symptoms. The symptoms of thalidomide syndrome are defined by absent or shortened limbs. Cuddlyable3 (talk) 07:28, 14 June 2011 (UTC)

Right, so no third arm. StuRat (talk) 07:35, 14 June 2011 (UTC)

lunar eclipse

How full moon appers during lunar eclipse?' ' — Preceding unsigned comment added by 14.97.111.145 (talk) 08:46, 14 June 2011 (UTC)

See our articles lunar eclipse and full moon. I think they make sense, let us know if you have a specific question.--Lgriot (talk) 09:39, 14 June 2011 (UTC)

The requisite of a lunar eclipse is a completely shadow covered moon. You can't have a full moon concurrently occuring with a lunar eclipse. The moon is too big to have properties like a quantum superposition. Plasmic Physics (talk) 11:26, 14 June 2011 (UTC)

A lunar eclipse only happens at full moon. It usually has a reddish or brown tinge. Graeme Bartlett (talk) 12:51, 14 June 2011 (UTC)

Not concurrently, but in sequence. Plasmic Physics (talk) 13:13, 14 June 2011 (UTC)

No, really concurrently. Obviously, a lunar eclipse can only happen when the moon is on the exact opposite side of the Earth than the Sun. We call that a full moon. Just because most of the light is blocked doesn't change that - it's still considered a full moon. --Tango (talk) 22:00, 14 June 2011 (UTC)

Full phase might be a better term. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:21, 15 June 2011 (UTC)

I would argue that a lunar eclipse is the fullest possible full moon. 86.160.218.204 (talk) 13:54, 14 June 2011 (UTC)

It is not surprising that this question located to Hyderabad where they will experience the full glory of the June_2011_lunar_eclipse. Richard Avery (talk) 18:08, 14 June 2011 (UTC)

Lunar eclipses happen at Full Moon, and solar eclipses happen at New Moon. Furthermore, eclipses very often come in pairs, 2 weeks apart. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:19, 15 June 2011 (UTC)

transduction, transformation, transfection and electroporation

Is there an umbrella term for transduction, transformation, transfection and electroporation? --129.215.47.59 (talk) 11:31, 14 June 2011 (UTC)

Perhaps: transgenic introductive techniques. Plasmic Physics (talk) 11:56, 14 June 2011 (UTC)

Raspberries

According to the article, each raspberry contains only a single seed, so why are there so many pips in raspberry jam and yoghurt? Aren't they all seeds? As far as I recall, when I eat fresh raspberries, there are no pips.--Shantavira|^{feed me} 13:29, 14 June 2011 (UTC)

The article says "An individual raspberry weighs about 4 g, on average and is made up of around 100 drupelets, each of which consists of a juicy pulp and a single central seed. " So each raspberry contains about a hundred seeds. Whenever I eat fresh raspberries (which is as often as possible), I always get pips in my teeth. DuncanHill (talk) 13:34, 14 June 2011 (UTC)

Oh I misread it, thanks.--Shantavira|^{feed me} 14:57, 14 June 2011 (UTC)

Soundproofing with solids

This is something I've never understood. If sound moves fastest in solids, why are solids used for soundproofing? Metroman (talk) 13:43, 14 June 2011 (UTC)

Mostly, by intentionally designing a system to be poorly impedance matched to air. The key is that a large change in sound velocity means that the transfer of energy between two materials is poor. So, even if a material like solid steel conducts sound very well, at a high speed and with low attenuation, that sound doesn't transfer well from steel to air (and back). Most energy will be reflected at the surface. In addition, incoherency and diffusion are exploited by shaping the surface... a good sound barrier will be a rough surface (and a great sound barrier will be diffusive acoustic cones as you see in a studio booth). This way, you minimze the transmitted sound and the reflected sound. Nimur (talk) 14:15, 14 June 2011 (UTC)

The most common type of soundproofing I'm familiar with, like the kind used in recording studios is made of sponge. sponge is elastic so the little cells of air tend to absorb and dissipate sound energy rather then propagate it like a rigid solid. Vespine (talk) 00:16, 15 June 2011 (UTC)

Yes. Rubber or other elastomer has pronounced elastic hysteresis by which most received vibrational (sound) energy gets converted to heat. Cuddlyable3 (talk) 11:53, 15 June 2011 (UTC)

What is used to block ultra low frequency sound? It doesn't seem like anything but water or heavy masonry affects it very much. Wnt (talk) 06:01, 16 June 2011 (UTC)

Unstable nuclei

Hi. Is there any qualitative difference between an atomic nucleus that is extremely unstable (arbitarily so) and one that simply can't exist at all? For example, suppose I took x protons and y neutrons, for some arbitrary x and y, and stuffed them together to make a nucleus, which then blew up effectively instantly but actually in some tiny amount of time like 10^-15 seconds, or whatever value it might be. Have I thus always created a nucleus with an extremely short half-life, or might I have tried to create one that simply can't ever exist, and can't meaningfully have a "half-life" assigned? 86.160.218.204 (talk) 13:51, 14 June 2011 (UTC)

How do you propose to stuff them together? You don't just pick out protons and neutrons from little trays, and apply some gluons and then let go and see if it sticks. You'd need a real possible procedure to create your proposed nuclei. Also, something with a half-life of 10^-15 seconds is still a real amount of time, several mesons (see List of mesons) have half-lives several orders of magnitude shorter than that before they disintegrate into their constituent particles, and they "exist". The answer is, if it exists, it exists and if it does not, it does not. The length of time is irrelevent, all that is relevent is if you can establish evidence of its existence in the first place. There's lots of ways to establish evidence of existing; and these don't always involve keeping a bunch of it in a jar long enough to do tests on it. To take two examples, the neutral pion has been positively confirmed to exist, despite having a halflife of 10^-21 seconds, see Pion#History. On the flipside, the Higgs boson has never been detected though many (not all, but many) models of particle physics predict, and rely upon, its existence. --Jayron32 15:05, 14 June 2011 (UTC)

The way in which they are stuffed together is not relevant to the question I want to ask. Just imagine that the requisite particles are in place in a putative nucleus and take it from there -- a kind of thought experiment, if you like. If the question can't be asked, even in principle, without knowing exactly how this state was achieved, then I guess my question makes no sense. As you can probably imagine, "if it exists, it exists and if it does not, it does not" is not the answer I was seeking. I have thought of another way to ask this which may be clearer: imagine you are compiling a table of all possible atoms -- that is, all values of my x and y -- in decreasing order of half-life. Is there some point at which you must stop and draw a line (that is, when there is a qualitative change from unstable atoms with a definable half-life, to "non-atoms" that simply aren't viable at all, even with no matter how short a half-life) -- or do you go on, in principle indefinitely, with the half-life just getting shorter and shorter? 86.179.117.174 (talk) 17:39, 14 June 2011 (UTC)

I believe what you are looking for can be answered in a few articles. There are ways to predict which nuclei should be stable enough to be considered to "exist" for a reasonable amount of time (reasonable as defined by Dauto below), one of the most common is the Nuclear shell model. The table of all possible atoms also exists. See Island of stability for a graph exactly like you want. --Jayron32 18:53, 14 June 2011 (UTC)

Yes. A viable nucleus must, at minimum, have positive nuclear binding energy. This means the strong nuclear forces holding the nucleus together have greater impact than the electrostatic repulsion trying to drive the protons apart. In principle, the binding energy can be modeled via quantum chromodynamics, though in practice it is often an impractically difficult computational problem for large atoms. Also, though this is a necessary condition, it isn't sufficient since some potential nuclei will fission without having been self-bound for any meaningful length of time (i.e. without even allowing binding forces to cross the whole nucleus). Dragons flight (talk) 19:12, 14 June 2011 (UTC)

That question shouldn't be dismissed so handedly. There are two aspects that should be taken into consideration. First, if the decaying object is a composite structure such as a nucleus, as opposed to a fundamental particle such as a quark or a gauge boson, than if its life time is too short there will not be enough time for light (or anything else) to cross its length before it decays and there is no meaningful reason to call it a particle. For the nucleus example the relevant length is 10^-15 m. Light takes about 10^-23 s to cross that length therefore no nuclei can exist with a lifetime shorter than that. The second point to take into consideration is that because of the uncertainty principle a particle with a very short lifetime will have a large uncertainty to its total energy. If that uncertainty is larger than the mass of the particle itself than we should more properly talk about a Resonance (particle physics) instead of a particle. Dauto (talk) 16:25, 14 June 2011 (UTC)

Fingerprints

I read the article Fingerprint and even saw the use of the word "point" without clear definition. Nowhere did it explain what a "point" is in the context of fingerprints. On television, both in fiction and nonfiction, I've heard people speak of two fingerprints having X number of matching points, and sometimes they show a picture of a fingerprint with little squares or circles drawn on the fingerprint. Who decided to draw the points right where they are? If I draw a bunch of line curves, what's the objective method of deciding where any point is to be on any of those curves? 20.137.18.50 (talk) 18:03, 14 June 2011 (UTC)

A "point" is a common term which applies to an identifying characteristic of a particular print. In fingerprinting, these are often called "Minutiae" and applies to a set of "common" features which appear at specific locals in specific fingerprints. It isn't a simple problem, which is why a "positive" connection requires a sizable number of common "points" to call it a "match". What you have is an overall pattern of the print (a "whorl" or an "arch" or a "loop" are the three most common patterns) and within the main pattern are small features which are unique to the individual, like say you have a whorl-type print. Lets say on a line drawn at 12:00 from the center of the whorl, you have a gap on the third ridge, and there's a connecting bit between the fifth and sixth ridges, while on the line drawn at 3:00, there's gaps on the second and fourth ridge, etc. etc. This is in general how prints are identified; in reality the language used to describe the "points" and the manner in which they are connected between the sample print and the suspect print are much more precise than I have done here, but that should give you the idea. --Jayron32 18:47, 14 June 2011 (UTC)

diffrence

how can u distinguish between Allene and Alkyne? i know about bayers reagent test but both of them give it so there is no physical distinction((both discharge color of KMnO4).So my question is is there any other test which distinguish between Alkene and Alkyne physically. Can Ozonolysis be a authentic test for them? — Preceding unsigned comment added by 175.110.91.49 (talk) 21:13, 14 June 2011 (UTC)

There is distinction, an allene has an "sp" carbon bonded to two "sp2" carbons, while an alkyne has an two "sp" carbons bonded to each other and one other atom. However, you are correct in that allenes and alkynes are particularly tricky to identify via "wet chemistry" analytical techniques; this is because allenes and alkynes are frequently in equilibrium, see Propadiene, which exists normally as an equilibrium mixture with propyne (likewise, propyne will exist in the same equilibrium with propadiene) called MAPD. Any reaction which would react preferentially with the allene will simply, via Le Chatelier's principle, cause the equilibrium to shift to convert more alkyne to allene, and the same in reverse as well. There are likely ways to use technology to do the job for you, for example they may produce distinctly different peaks in IR spectroscopy or something like NMR or mass spectrometry may be very useful in this regard; however you may be correct in that it is almost impossible distinguish them via chemical reactivity. Ozonolysis may be an option, as you note, since ozonolysis of an alkyne should produce two carboxylic acids, while ozonolysis of an allene should produce carbon dioxide and two aldehydes. However, given the equilibrium situation I note, that may foil whichever ozonolysis reaction of the two is slower; the equilibrium situation would just cause the faster ozonolysis reaction to drive the reaction kinetics, and the other wouldn't happen. --Jayron32 23:24, 14 June 2011 (UTC)

Try infrared spectroscopic analysis, alkynes gives an absorption peak at a higher wave number. If you heat alkynes, they tend to polymerise easier. Plasmic Physics (talk) 23:26, 14 June 2011 (UTC)

Thank for the answer. my exams is on friday and i was a little confused.Can u suggest any links or articles.I am in 12 standard. — Preceding unsigned comment added by 175.110.91.49 (talk) 23:56, 14 June 2011 (UTC)

Physics and timetravel

I am interested in writing a short story about a scientist who creates a time machine. Instead of going to a certain year, he is accidentally catapulted to the very beginning of time billions of years ago. I know very little about physics. Was time as we know it created the very second that the big bang took place, or some other time? I'm just interested to learn if it is at least plausible for someone to go back to that exact moment (that is assuming time travel is possible in this scenario). --Ghostexorcist (talk) 22:30, 14 June 2011 (UTC)

At that instant the entire universe was smaller than an atomic nucleus. Looie496 (talk) 22:38, 14 June 2011 (UTC)

(edit conflict)Matter as we know it could not exist until the universe was about 380,000 years old, so the physicist would instantly transform into plasma, presuming time travel possible. See Timeline of the Big Bang.

If we assume that he somehow shields himself from the extreme energies at that time (this is science fiction after all), you have to consider that you can't go further back than the instant the universe began (my favorite analogy: going back before the big bang is like trying to go North from the North Pole), and at that instant, it was (practically) infinitely dense. At some point backwards, the universe itself would be smaller than the time-traveling scientist himself, so you can see why this would present a problem! There really is no practical way, even in the structure of a fictional time-travel book, to plausibly go back to the instant the universe was created. For this, you need to delve more into the "fiction" part of "science fiction".-RunningOnBrains^(talk) 22:44, 14 June 2011 (UTC)

What is a good book that explains the most current research on the big bang that is dumbed down enough for the average joe interested in science? --Ghostexorcist (talk) 08:04, 15 June 2011 (UTC)

Thanks for the informative response. As for shielding, I was thinking that some strange quark of him physically traveling back through time (he doesn't travel in a machine) makes him immortal. His body is petrified into a rock like substance, in effect becoming a living statue. Going back to the beginning of the universe is just something I thought of a second ago. I originally conceived the idea of him going back to the earliest days of human civilization. He watches the rise and fall of various cultures over the course of thousands of years. Now that you have thoroughly answered my question, I would like to pose a related query. --Ghostexorcist (talk) 23:05, 14 June 2011 (UTC)

My favourite for unexpected time travel effects is the scientist who built a time travel machine to find out what caused the snowball earth. As it is impossible to send matter back, he sends information to rebuild the matter (himself and the time-ship). Unfortunately part of the matter uptake was in the form of heat energy so as a result, the whole earth got frozen. 5BYv8cUJ (talk) 09:39, 15 June 2011 (UTC)

Time travel and biology

What fictional process could effect the scientist's body in such a way that it would become living stone. I imagine that it would have to effect his body's natural atomic bond. Again, I know very little of physics. --Ghostexorcist (talk) 23:05, 14 June 2011 (UTC)

I don't know, you tell us, it is your work fiction after all. What is a human body's natural atomic bond? For that matter, what is an atomic bond? Plasmic Physics (talk) 23:20, 14 June 2011 (UTC)

That's why I said "Again, I know very little of physics" above. I guess his atomic bond would be the spacial density of his atoms. Then again, I have read that this density is fixed and cannot be change, so just consider that a bad word choice. I'm just interested in some type of real world explanation that can be greatly embellished. Like for instance, if you expose a certain element to a given energy source, does it effect its density in any way? If there is none, then I'll just shoot from the hip. --Ghostexorcist (talk) 23:27, 14 June 2011 (UTC)

An important clarification: what properties of stone do you want this living body to have? For instance, the hardness of stone is not (primarily) due to the density, but the crystal lattice structure of the mineral components. Once you have that hardness via the crystalline structure, malleability (e.g. the ability to move around) becomes a problem... SemanticMantis (talk) 23:43, 14 June 2011 (UTC)

I haven't the slightest clue to tell you the truth. I know living rock can move like toothpaste given enough pressure, but it's not like the guy is trapped between tectonic plates or anything. I guess I'll have to relegate this portion of the story to the fiction side of sci-fi. --Ghostexorcist (talk) 23:52, 14 June 2011 (UTC)

The idea reminds me more of golems, gnomes or other fantastical creatures anyway... you can always say a wizard did it ;) SemanticMantis (talk) 00:24, 15 June 2011 (UTC)

How about a supersolid? Plasmic Physics (talk) 06:34, 15 June 2011 (UTC)

Thanks for reminding me of this. I'll look into it more. --Ghostexorcist (talk) 08:04, 15 June 2011 (UTC)

Since this is fiction your protagonist could meet up with the Gorgon. Insert obvious phallic joke here. You may find more scientific ideas in the article Fossil although your plot should allow plenty of time for this slow process. Note that fossilization will affect and not effect the body. Cuddlyable3 (talk) 11:37, 15 June 2011 (UTC)

phone tracing

Usually in movies it takes some time until the phone number of a caller can be traced. So they have to keep them on the line for a certain amount of time until they get the number. This sounds like BS to me, as the phone company certainly has the caller's number in real time. What are the technical reasons behind this? Is/was there at all any truth about this? --helohe (talk) 22:37, 14 June 2011 (UTC)

Technological capabilities at the present time may be superior to technological capabilities when the movie was made. Looie496 (talk) 22:39, 14 June 2011 (UTC)

No, they have pretty much always been bullshit, at least since the advent of relatively modern phone-switching systems (i.e. something better than women with headphones moving wires around a giant pegboard). Telephone_exchange#Digital_switches indicates that digital systems have been in place since the 1980's. Caller_ID#History indicates that the technology has existed, theoretically, since 1969, to instantly display a caller's phone number, though the first market-ready applications were in the mid 1980's. I'm sure at some point in the past this really was a major undertaking to "trace" a call, but given that for at least 20 years, my phone has been able to automatically tell me who is calling, and I am not the police, then any movie in the past 20 years where the police can't do so is bullshitting us. this article confirms that, during the days of manual switching it used to take upwards of 20 minutes to trace a call, and required the cooperation of the phone company. However, with the advent of electronic switching techniques, tracing calls went from "20 minutes for the phone company to track someone down" to "instantaneous". There was never a time when a call could be traced in an automated way, like you see in movies and cop shows, but did not return results essentially as soon as the connection was made. The whole "keep him talking while we trace the call" bit has always been an invention of scriptwriters. Either (pre-1980's) you had to get the phone company to figure out who called (and this didn't require the other person to be on the line; they could figure where it came from after they hung up) OR (modern systems) you can find out instantly as soon as the connection is made. --Jayron32 23:12, 14 June 2011 (UTC)

I've always had the suspicion that this is the result of not just the drama involved (to avoid making things too easy on the protagonists) but also script writers not wanting to give away the FBI's tricks. For instance even on shows where it would be great to have you never see them use portable cell towers for triangulation and to lock down a hostage taker's cell phone (by forcing it to connect to YOUR tower rather than the network at large) despite the fact the technology exists. HominidMachinae (talk) 00:54, 15 June 2011 (UTC)

I think some of the respondents above may be making a false analogy between the telephone network and the Internet. The Internet was designed to be stateless and is based on datagrams (i.e., postcards). You have to supply a legitimate return address if you want to get a reply, unfortunately for your privacy. The telephone network doesn't work that way. It is circuit switched, which means that every switch on the network behaves more or less like a NAT router. How do you find out which of the computers behind a NAT router was the source of an outgoing connection? You don't, unless the sender identifies itself or the router exposes an interface that can be used to query that information. I'm sure that mechanisms for fast call tracing have existed for a long time, because the spooks demand it, but it's not in the nature of the telephone network to expose the caller's identity, unlike the Internet. Caller ID works by sending the calling number over the circuit once it's made, encoded as pulses. The receiving phone displays whatever information is sent, even if it's wrong. It doesn't really know who's calling. -- BenRG (talk) 06:26, 15 June 2011 (UTC)

It should be noted that caller ID is completely unrelated to call tracing. A trick from the old days included tandem stacking, which would let one bounce a call back and forth across the US, and then connect to a given number (which would sometimes have the effect of the local telco's central office number showing up.) Similarly, using a calling card to place a call will often give the Caller ID for the calling card company, not the pay phone from where the call was originally placed. Related to this is ANI, which is included on all 800-numbers, as well as all law enforcement phone systems. One can block their caller ID, but they cannot block the ANI function. (although ANI information can also be spoofed by proper call routing.) None of this affects call tracing, but can affect the perceived origin of a call for your average citizen (or their Caller ID equipment.) ^Avic_ennasis @ 09:38, 13 Sivan 5771 / 15 June 2011 (UTC)

You have to take into account the fact that the telephone company has historically kept records for billing purposes, not because they cared about tracking any single person's actual physical location. There are and have been all sorts of legacy physical situations which may simply make tracing a specific land line call from a specific land line area very difficult. It's not an either/or situation, but a hugely complex process depending on circumstances, such as flat rate and party line (telephony). μηδείς (talk) 19:28, 16 June 2011 (UTC)

June 15

Measurement Unit Of Malleability

What is the measurement of malleability?Curb Chain (talk) 05:00, 15 June 2011 (UTC)

Malleability is the ability of a metal to be hammered into thin flat sheets, see the article Ductility. An example of a very malleable metal is gold. Malleability is an example of non-linear behaviour of a material that is stressed beyond its elastic limit (below which many materials obey a linear Hooke's law). There are approximate mathematical descriptions of material plasticity, see here, but I think there is no standard measurement unit and only empirical data on how materials behave beyond their yield point. Cuddlyable3 (talk) 11:14, 15 June 2011 (UTC)

Putting Humpty Dumpty back together again

In various medical dramas, I've seen doctors do everything from move intestines aside to get at something to basically scooping them out of the abdominal cavity and move them aside. Granted, these are works of fiction, so I don't think that they're always very accurate. What I'm wondering though is on the other end of things. When the patient has been saved and all their organs need to go back into their body, how much care needs to be taken to make sure the intestines aren't knotted up or laying incorrectly or something. Is there a process or procedure to putting them back in? Dismas|^(talk) 06:19, 15 June 2011 (UTC)

My Dad had such a surgery, where his intestines were pulled out, then put back in, and they seemed to think they would just "find their way back" to the right spot. They didn't. From then on he was noticeably lopsided, with a bulge on one side of his abdomen. StuRat (talk) 07:07, 15 June 2011 (UTC)

I wonder if it was possible that your dad had a slight incisional hernia which weakened part of his abdominal wall and the pressure of the abdominal contents pushed out rather more on one side than the other, not uncommon in major abdominal surgery. Within the abdomen where the intestines are is a single cavity which would exert even pressure against the whole abdominal wall. I don't believe there is a right spot for removed and replaced intestines. The most important factors are that when they are replaced they should not have their blood supply compromised and the intestine should not be twisted, stretched or knotted in a way that peristalsis would not be able to correct. Richard Avery (talk) 14:39, 15 June 2011 (UTC)

The way the body packs the contents of the abdominal cavity can vary. An embryo is a different payload than the OP talks about, but its positioning is sometimes unlucky, see for example Breech birth and Umbilical cord prolapse. Cuddlyable3 (talk) 09:45, 15 June 2011 (UTC)

I think the answer is, "with great difficulty" - my sense is that with intestinal surgery, if the surgeons don't do everything just right (and maybe even if they do) necrosis of the bowel can occur. Wnt (talk) 00:35, 16 June 2011 (UTC)

I am a mechanical engineer now i need a notes for the following topics

Specific requirements for automotive lubricants – Oxidation deterioration and degradation of lubricants – Additives and additive mechanism – Synthetic lubricants – Classification of lubricating oils – Properties of lubricating oils – Tests on lubricants – Grease – Classification – Properties – Test used in grease. — Preceding unsigned comment added by Vigneshvig88 (talk • contribs) 09:38, 15 June 2011 (UTC)

Your list of subjects looks like a whole course in lubrication. A place to start is the article Lubricant and move on to Lubricant#Application by fluid types. There are a number of e-books on lubrication fundamentalsthat I have not read but that may be helpful. Cuddlyable3 (talk) 10:01, 15 June 2011 (UTC)

Our article on tribology (the science of friction and lubrication) may also be useful. Gandalf61 (talk) 10:53, 15 June 2011 (UTC)

Respondents: I've started a discussion of this question here. --Sean 19:56, 15 June 2011 (UTC)

Multiple biopsy

Do doctors perform biopsy on a cancer patient several times to discover how the cancer is developing? Or is it a one time shot? 2.139.12.164 (talk) 09:50, 15 June 2011 (UTC)

As with most questions like this one, it depends on the circumstances. There are some scenarios where several biopsies might be employed to assess for distant metastases of solid tumors, or serial bone marrow biopsies might be used to follow leukemia. --- Medical geneticist (talk) 10:18, 15 June 2011 (UTC)

Clearly more than one measurement at different times is needed to determine how anything is developing. Cuddlyable3 (talk) 11:17, 15 June 2011 (UTC)

True, but it need not be a biopsy, per se... often the cancer will be followed by less invasive imaging techniques such as positron emission tomography. Again, it is an "it depends" kind of answer. --- Medical geneticist (talk) 11:33, 15 June 2011 (UTC)

Medical geneticist's response is spot on; it really depends on the circumstances. For a specific example, a prostate biopsy will often be performed in the event of suspected prostate cancer. Because these tumors are often very slow-growing and the patients who develop them tend to be older, low-grade tumors – those with a low Gleason score – can sometimes be left in place untreated. The risk of disease progression during a period of watchful waiting may be less serious than the risk of negative side effects caused by more aggressive therapy. (Indeed, four out of five men over the age of 80 probably have prostate cancer. Most will never even know about it, because they'll die of something else long before the prostate cancer gets them.) If the patient's symptoms become more severe (or there are other signs of disease progression like an increasing PSA score) then another biopsy may be performed to determine if the cancer has become more aggressive. TenOfAllTrades(talk) 14:14, 15 June 2011 (UTC)

Light's behaviour

Why light travel in straight light? — Preceding unsigned comment added by Ahsanshkh (talk • contribs) 11:27, 15 June 2011 (UTC)

Because everything that is not deflected travels in a straight line. But even light does not always travel in a straight line. See lenses, prism and also gravitational lens. 5BYv8cUJ (talk) 11:34, 15 June 2011 (UTC)

Also relevent in this case is Geodesic (general relativity). One needs to define what it means to be a "straight line" before one can decide how and why light travels that way... --Jayron32 11:55, 15 June 2011 (UTC)

The Poynting vector is not a simple explanation why light, an electromagnetic radiation, travels in a straight line, but it serves to show how light's behaviour relates to its constituent electric and magnetic fields. Cuddlyable3 (talk) 13:09, 15 June 2011 (UTC)

See conservation of momentum. Light has a relativistic mass which depends on the energy carried by the photon (by E=mc²), which in turn is equal to the frequency in cycles per second times Planck's constant (or the frequency in radians times Planck's reduced constant... same thing). So light of a given frequency has a proportional amount of mass, traveling at the speed of light. (Hmmm, on second thought, that's a bit mind boggling - see Momentum#Momentum in electromagnetism and even Abraham-Minkowski controversy. You know once the name Minkowski comes up, you're not in Kansas any more ;)) This momentum doesn't change unless something acts on it. Wnt (talk) 00:42, 16 June 2011 (UTC)

Fundamentally, because of the homogeneity and isotropy of space. The laws of physics have to be such that light in a flat vacuum travels in a straight line, because there's nothing that would enable the light to "choose" a new direction to go in. It's a matter of symmetry. Red Act (talk) 02:57, 16 June 2011 (UTC)

That's right. And that accounts for the deflections and refractions implicit in the first response above. Whatever direction it's going in, it will continue to go in that direction until and unless some external force (such as a lens, prism, mirror, reflective surface, etc) makes it go in a different direction. -- Jack of Oz ^{[your turn]} 13:17, 16 June 2011 (UTC)

Neutrino oscillations and CP violation

"Neutrino particle 'flips to all flavours'" (BBC News) says that the T2K experiment has announced provisional results that indicate that muon neutrinos can transform into electron neutrinos, and hence the θ₁₃ component of the neutrino mixing matrix is non-zero. I follow all of that (after a hand-waving fashion). The article then goes on to say that this type of neutrino oscillation would be an example of CP violation. However, it doesn't really explain just how these particular neutrino oscillations violate CP symmetry. Can anyone explain the connection in more detail, please ? Gandalf61 (talk) 12:27, 15 June 2011 (UTC)

Neutrino mixing is governed by the Pontecorvo–Maki–Nakagawa–Sakata matrix. In principle, this involves 9 complex numbers. However, after requiring the total amplitudes to remain constant over time, assuming that all neutrinos always have the same chirality (which is true as far as we can tell), and assuming neutrinos are Dirac fermions (like all other known fermions, but the Majorana fermion model is not experimentally excluded), this reduces the 18 nominal degrees of freedom to only 4 real numbers. In particular, CP violation occurs if and only if the imaginary part of $sin(\theta _{13})e^{-i\delta }\neq 0$, where $\theta _{13}$ and $\delta$ are numbers to be determined experimentally. A non-zero imaginary part would imply that nuetrinos and antineutrinos have different mixing rates, or in other words, in a CP-inverted universe neutrino mixing rates wouldn't look the same (hence CP-violation). $\theta _{13}$ is known to be small, but the current report suggests it is non-zero. Incidentally, $\delta$ is also unknown and could be 0, so $\theta _{13}\neq 0$ is a necessary but not sufficient condition to show where neutrinos oscillations violate CP-symmetry. Dragons flight (talk) 20:13, 15 June 2011 (UTC)

(ec) A non-real entry in the mixing matrix violates the C part of CP, which is complex conjugation. The standard parametrization consists of three Euler angles (θ₁₂, θ₂₃, θ₁₃) and one complex phase (δ₁₃). This article is about a new constraint on θ₁₃. If you look at CKM matrix#"Standard" parameters you'll see that all of the terms with δ₁₃ in them also have a factor of sin θ₁₃. So, one could say that a nonzero value of θ₁₃ "opens up the possibility" of CP violation, since the matrix is real if θ₁₃ = 0 regardless of the value of δ₁₃. But it's a stupid thing to say because (1) this parametrization is arbitrary and (2) there was never any reason to expect any of these parameters to be zero, and it would be very strange if they were, so the possibility has always been open and the only interesting result, in that connection, would be one that "closed it off". It's basically the same as saying "we have determined that we are not standing precisely at the North Pole, which opens up the possibility that we are not standing precisely on the Greenwich Meridian." -- BenRG (talk) 20:21, 15 June 2011 (UTC)

Thanks for the excellent responses. So, if I understand this correctly, CP violation will occur if both θ₁₃ and δ₁₃ are non-zero, but the provisional T2K results only establishes one of these conditions. So what sort of experiment would be required to measure the value of δ₁₃ and/or to directly demonstrate CP violation in neutrino oscillations ? Are there any such experiments ongoing or at the planning stage ? Gandalf61 (talk)

δ₁₃ is much harder to measure, but proposals have been made. see for instance this paper. Dauto (talk) 16:39, 16 June 2011 (UTC)

Problems topping up mobile

Does anyone know what a 'Error Code-91 System Error' means ? Because i have tried to topup my mobile (T-mobile) at three different stores today and the same thing happened in each case, on the recepts was: 'Transaction Failed' 'Error Code-91' 'System Error' Does this mean my topup card, SIM card or both have been cancelled, which the staff in the stores believe it could be. Help!!!109.145.108.36 (talk) 12:41, 15 June 2011 (UTC)

It may help to note that the OP's IP is in the UK OK! OK! Enough abbreviations! so their mobile operator is T-Mobile (UK). Cuddlyable3 (talk) 12:56, 15 June 2011 (UTC)

Just doing a few obvious checks: have you taken the battery out and reseated it? Have you taken the SIM out and reseated it? Switched off and on again? --TammyMoet (talk) 14:49, 15 June 2011 (UTC)

Does T-mobile not have some sort of help line or email you can contact? Nil Einne (talk) 15:36, 15 June 2011 (UTC)

Try topping up your mobile via their website, or by text.--Shantavira|^{feed me} 16:13, 15 June 2011 (UTC)

I tried topping up again today and it worked first go. The system must have been down or some thing.109.145.108.36 (talk) 12:09, 16 June 2011 (UTC)

Horticulture Nurseries

What is a nursery? What types of nurseries are there? What are the opportunities and challenges of nurseries? — Preceding unsigned comment added by 62.24.111.249 (talk) 13:57, 15 June 2011 (UTC)

Please do your own homework.

Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. You may find the Wikipedia articles horticulture and plant nursery may help you, though your best option is to read through the text book that your teacher gave you and/or read the notes you wrote down during in-class lecture. --Jayron32 14:11, 15 June 2011 (UTC)

If the OP's homework was assigned not in a Biology class but in something related to Paediatrics or Pedagogy, then Nursery might be more relevant :-) . {The poster formerly known as 87.81.230.195} 90.197.66.241 (talk) 18:11, 15 June 2011 (UTC)

Directions near the Poles

Is there a standard way of giving direction at or near the North or South Pole? At lower latitudes, "the wind is from the south-west" means something.

But if someone set up a weather vane at the pole, how could they tell someone else which way the wind was blowing?

Thanks, Wanderer57 (talk) 15:01, 15 June 2011 (UTC)

If you want the smartass answer... if you're at the North Pole, the wind is always from the south. Otherwise, see this page. -Atmoz (talk) 16:56, 15 June 2011 (UTC)

The link that Atmoz provides says "By international agreement (WMO Manual on codes v. 1, Code Table 878), within one degree of the North Pole, the Greenwich (0 degree) meridian is used...i.e. within about 60 nautical miles of the North Pole, winds are reported according to a compass face, oriented so the "North" arrow points toward the 0 degree meridian, and in this restricted area, "North" no longer refers to the North pole, but to the observatory in Greenwich, England." That means nobody can say which way the wind blows at a spot in the Arctic 89°N 0°E. Cuddlyable3 (talk) 08:38, 16 June 2011 (UTC)

On first reading the NOAA page pointed out by Atmoz seemed to make sense. Rereading it, I'm not sure. It seems to imply that, when setting up a weather vane near the North Pole (an activity I hardly ever do but want to be prepared for), the north pointer should point toward the 0° meridian. But the 0° meridian is a line, not a point. What does it mean to point toward a line? Maybe I've got this all backwards. Please advise. Thank you. Wanderer57 (talk) 20:37, 16 June 2011 (UTC)

It is a line, but technically at the north pole, you are standing on the topmost point of that line, so the entire line is the same direction from you. Googlemeister (talk) 20:51, 16 June 2011 (UTC)

Nose to the Brain

Is there any truth to the idea of there being straight access from the nose to the brain or is that just a myth? — Preceding unsigned comment added by 71.143.240.229 (talk) 15:07, 15 June 2011 (UTC)

I don't know what you mean by "straight access", but consider the top diagrams at nasal cavity and human brain. The brain image also shows the nasal cavity, which appears to directly adjoin the brain at some points. SemanticMantis (talk) 15:34, 15 June 2011 (UTC)

What does "straight access" mean? direct unimpeded access? in that case, no. There is 1-2 mm layer of bone between the top of the nasal cavity and the base of the brain. Richard Avery (talk) 15:55, 15 June 2011 (UTC)

Is there also bone from the top of the ear to the brain, blocking access to the brain? — Preceding unsigned comment added by 70.136.157.251 (talk) 16:01, 15 June 2011 (UTC)

The olfactory receptor neurons connect to the olfactory nerve which connects to the olfactory bulb which connects to other parts of the brain via the olfactory tract - see olfactory system. Doesn't seem very much like "straight access" to me - not more so than the other sensory systems, anyway. Gandalf61 (talk) 16:11, 15 June 2011 (UTC)

How does cocaine get to the brain when sniffed if there is a bone between the nasal cavity and the base of the brain? — Preceding unsigned comment added by 70.136.157.251 (talk) 16:40, 15 June 2011 (UTC)

Thru the bloodstream. 67.169.177.176 (talk) 17:31, 15 June 2011 (UTC)

This one I know the answer to. For almost all of the classical sensory systems, the pathway from sensory organs to the cerebral cortex has a way-station in the thalamus. The olfactory system is the only one of the "five senses" for which signals can reach the cerebral cortex without passing through the thalamus -- olfactory receptors in the nasal epithelium project to the olfactory bulb, which projects to the olfactory cortex. Looie496 (talk) 18:19, 15 June 2011 (UTC)

"Straight access from the nose to the brain" might also refer to the danger triangle of the face. -- BenRG (talk) 18:53, 15 June 2011 (UTC)

I'm pretty sure the idea the OP is referring to is the one I described -- it is very commonly discussed in books or articles about the sense of smell. Looie496 (talk) 19:08, 15 June 2011 (UTC)

The sense of smell is so critical to the survival and brought such evolutionary advantage to early complex animals, that one could almost say that the brain is an extension of the olfactory bulbs rather than visa versa. http://www.sciencemag.org/content/332/6032/955 You can't get more direct than that. Later, part of this neural complex became light sensitive and became eyes. These developments happened independently in several different lifeforms. Someone may also be able to find reference to the sense of smell in humans, still over-riding all one's other senses. --Aspro (talk) 19:53, 15 June 2011 (UTC)

I think that's an exaggeration. Yes, mammals were little burrowing things that put a high priority on the sense of smell, but olfaction is just one sense of, say, fish. Go back far enough and you get to Cnidaria such as Cubomedusae, which have tiny organs which feature a surprisingly complex eye, a sort of ear (well, at least, a balance sensing organ), and an open vestibule for sense of smell. In bilateral animals I think the most general model you can apply is that the brain is a combination of ganglia in each segment (dorsal in vertebrates, ventral in arthropods, but homologous) which each have sensory and motor functions controlling the limbs and communicate up and down a nerve cord. I think the sensory organs are just features of primitive appendages (antennae, ear joints, stalked -> socketed eyes) with specialized sensory equipment leading to particularly massive processing centers in the brain. Wnt (talk) 06:31, 16 June 2011 (UTC)

I tried looking into this before at Wikipedia:Reference desk/Archives/Science/2011 April 7#Blood-brain Barrier. There is some exchange between blood flow in the nose and the brain, but the "blood-brain barrier" should be behind that - separating the brain from the blood vessels themselves. Yet there was one reference about a compound having better access, and I wasn't really sure why. Wnt (talk) 00:04, 16 June 2011 (UTC)

This reminds me of how the ancient egyptians removed the brain during the mumification process. How they have to tap the device with a small hammer to gain access to the skull. Plasmic Physics (talk) 02:26, 16 June 2011 (UTC)

spin current

An electrical current is generally unpolarized (consisting of 50% spin-up and 50% spin-down electrons); a spin polarized current is one with more electrons of either spin. By passing a current through a thick magnetic layer, one can produce a spin-polarized current. http://en.wikipedia.org/wiki/Spin_transfer

how come current is composed of half spin up and half spin down? is spin up magnetic north and spin down magnetic south? (apparently this is true is it correct Spin "up" would mean the electron is acting like a bar magnet whose north pole is pointing up; spin "down," the opposite.) — Preceding unsigned comment added by 82.38.96.241 (talk) 21:09, 15 June 2011 (UTC)

To be precise, half of them have the vertical component of the spin up while the other half has that component pointing down. The horizontal component being unknowable (which is not the same as unknown). Imporntant note: We talk about spin up and down by convention but we could just as well talk about spin left and spin right, or spin forward and spin backward if so we wished. Dauto (talk) 21:19, 15 June 2011 (UTC)

Personally, I prefer inside and outside. Plasmic Physics (talk) 00:28, 16 June 2011 (UTC)

so is there only really 2 directions of spin and they happen to provide the effect for the north and south magnet — Preceding unsigned comment added by 82.38.96.241 (talk) 21:22, 15 June 2011 (UTC)

It is more understandable to say that for unpolarized electrons the spin points in a random direction in space; however, the nature of quantum mechanics is that we can only ever measure one component of it's direction per electron. So we pick an axis in space (call it vertical), and see how many of them have a positive vertical component (up spin) and how many have a negative vertical component (down spin). Another aspect of quantum mechanics is that we can only really get positive or negative (not a magnitude). If you have a consistently polarized spin current you can get more information about the spin orientation by measuring many electrons, but you are strongly limited about the information that can get from any single electron because the act of measuring it changes it. Dragons flight (talk) 22:03, 15 June 2011 (UTC)

(EC) It's not really that there are only two directions of spin. Rather, it's a matter of no matter which direction you arbitrarily choose, if you measure the spin of an electron along that direction, there are only two possible values that the spin can be measured to be. So if you measure the spin along the z direction, for example, the spin will either be in the +z direction or the -z direction (the magnitude of the spin will be the same either way). The amount of spin in each of the x, y and z directions are not independent; after you measure the spin along one axis, you can't know anything about what the spin is along the other two axes. The measurement process basically messes up the spin along any orthogonal direction. For example, if you measure the spin in the z direction and it's in the +z direction, and then measure the spin in the x direction, and then measure the spin in the z direction again, it's a 50/50 chance as to whether the spin will be measured to be in the +z or -z direction in that final measurement. Red Act (talk) 22:08, 15 June 2011 (UTC)

Also worth pointing out that earth's magnetic field are believed to be produced by electric currents in its liquid core as opposed to electron's magnetism. Dauto (talk) 00:09, 16 June 2011 (UTC)

ADHD Medication Rankings

This question was removed [20]. I have restored it, because the remover was wrong, and it does not violate any of our medical advice guidelines. Note that I have not restored one response, as it may have violated our guidelines. See also the discussion on the talk page. Buddy431 (talk) 00:44, 16 June 2011 (UTC)

I can specifically find all of the ADHD medication and dosages. I can not find which one is stronger than the other. Like Adderall XR is the slow relsease, but is Vyvanse more powerful? Adding a section to list ADHD medications ranking them from the smallest (such as Adderall) to a more powerful or longer lasting medication (such as Concerta and Adderall XR) would be very helpful in my opinion. Thank you for any knowledge on this subject. — Preceding unsigned comment added by IT Zach P (talk • contribs) 21:55, 15 June 2011 (UTC)

I think discussion on the talk page favors retention of the question; in any case, in general it is not so simple to answer. While it can seem easy to say that one chemical is more potent than another, it's not like comparing 9 to 10. The dosage for either drug can be adjusted up or down. The affinity constant, bioavailability, and pharmacokinetics can differ in different ways. One compound might be a complete agonist or antagonist, while another has some mixture of these activities. One compound might be more potent, but have more serious side effects. To give a simple example, everyone knows that "heroin is more potent than morphine" - yet when a soldier has had a piece blown off on the battlefield, he still receives morphine, because it's the most potent all-around painkiller. You can evaluate which drug is "most potent" in that sense - what you would use to get the job done in a certain situation - and in general this is the basis of medical diagnosis and prescription. But the fact that all these drugs are still out on the market is a sign that there may no hard evidence to say which one is best for all people. Wnt (talk) 00:17, 16 June 2011 (UTC)

Monkey from Antalya, Turkey?

Sorry, if this is not the best place to ask this question. Can anyone tell me what kind of monkey this is? --Phagopsych (talk) 22:00, 15 June 2011 (UTC)

Maybe a Spider monkey? (Just a guess.) Bus stop (talk) 22:08, 15 June 2011 (UTC)

I think it's a vervet monkey, but there are a number of species that look pretty similar. Looie496 (talk) 23:07, 15 June 2011 (UTC)

...or maybe a grivet, which is very closely related to a vervet. Looie496 (talk) 23:17, 15 June 2011 (UTC)

Incidentally, this is exactly the right place to ask this question. StuRat (talk) 08:35, 16 June 2011 (UTC)

Thanks a lot. In the pic doesn't show very well but it has none or very little hair on the top of head (you know, that darker grey bit). Also it had a very long tail, like the Vervet monkey, but the head looks more like the grivet's. Lovely animal, by the way. Very friendly. I know they should not be kept as pets but it was really playful and affectionate, jumping to people's arms without much of a prompt :-) --Phagopsych (talk) 19:12, 16 June 2011 (UTC)

Why no CO2 clouds high in the atmosphere?

Phase plot for carbon dioxide

Why doesn't CO2 condense into clouds where the temperature is low enough? Count Iblis (talk) 23:30, 15 June 2011 (UTC)

The minimum temperature in the atmosphere occurs at the base of the ionosphere, and is usually in the 250-300 Kelvin range. As you can see from the plot I have attached, CO2 does not have a stable solid phase in that temperature range at low pressures. Looie496 (talk) 23:49, 15 June 2011 (UTC)

There has been much speculation that polar mesospheric clouds, sometimes known as noctilucent clouds, are seeded by carbon dioxide crystals. Mesospheric clouds on other planets, especially Mars, have been observed to contain mostly carbon-dioxide ice. Other planets, like Jupiter and Neptune, also have mesospheres (of a sort); clouds in these planets can contain carbon dioxide, ammonia, and especially methane ice. Nimur (talk) 02:52, 16 June 2011 (UTC)

The difference is, the mesospheric temperatures on all those planets are much colder than on Earth. 67.169.177.176 (talk) 08:39, 16 June 2011 (UTC)

More importantly, the pressures of those planets are much higher than similar temperatured regions on earth. Phase is a function of both pressure and temperature; on Earth the coldest part of the atmosphere is of a pressure which is far to low to allow carbon dioxide to condense into crystals. On larger planets, like Juptier and Neptune, the lower levels of insolation means lower temperatures, while the greater mass means greater gravity, and thus greater atmospheric pressures. The OP appears to be considering only the temperature when questioning if CO2 should condense in the upper atmosphere of Earth. --Jayron32 12:15, 16 June 2011 (UTC)

Isn't it partial pressure, not pressure, that matters? High pressure doesn't necessarily mean high partial pressure. --Tango (talk) 12:34, 16 June 2011 (UTC)

Indeed, but there is no where on Earth where even the total pressure of the atmosphere exceeds the minimum pressure required to have CO2 condense. Logic would seem to dictate that a gas which makes up a fraction of that total cannot exceed the total itself, so rather self-evidently there is nowhere on Earth where CO2 should spontaneously condense. --Jayron32 15:26, 16 June 2011 (UTC)

I see, I forgot about the pressure :) . Count Iblis (talk) 17:01, 16 June 2011 (UTC)

Note that the graph at right only goes down to 200K however...at lower temperatures CO₂ will sublimate at Earth-like pressures and even lower; Mars has a surface pressure of around 10% of Earth's at most, and they have a large cap of CO₂ ice at each pole, as well as carbon dioxide clouds at several different layers of the atmosphere.-RunningOnBrains^(talk) 17:04, 16 June 2011 (UTC)

Sure, but below 200K isn't Earth-like temperatures (at any altitude), so what happens at Earth-like pressures at those temperatures isn't particularly interesting. --Tango (talk) 18:00, 16 June 2011 (UTC)

The mesosphere article says: "The upper boundary of the mesosphere is the mesopause, which can be the coldest naturally-occurring place on Earth with temperatures below 130 K." Count Iblis (talk) 19:51, 16 June 2011 (UTC)

Some places in Antarctica (e.g. the Vostok station) can get below 200 K in the winter. 67.169.177.176 (talk) 20:17, 16 June 2011 (UTC)

And as far as the mesosphere is concerned, note that the partial pressure of CO2 is many times lower than at sea level, which further hinders condensation. Also, at such high altitudes it's possible to start getting some UV-induced dissociation of CO2 into O1 (atomic oxygen) and CO -- which would further reduce the partial pressure. FWIW 67.169.177.176 (talk) 20:38, 16 June 2011 (UTC)

June 16

physics questions

what is "Akash"? — Preceding unsigned comment added by Qwshubham (talk • contribs) 07:51, 16 June 2011 (UTC)

Akash is the Sanskrit word for aether. Although there were aether theories in early modern physics, in particular the luminiferous aether theory, those theories have long since been discarded, and are not a part of modern physics. Red Act (talk) 08:08, 16 June 2011 (UTC)

Well, although that name isn't used any more, there may very well be a substance in the apparent vacuum of space that isn't obvious. For example, there's the dark matter theory. StuRat (talk) 08:41, 16 June 2011 (UTC)

I don't know about its use in physics, but if this question was on the language desk I would point out that the word is more generally used to mean the sky or space.--Shantavira|^{feed me} 11:54, 16 June 2011 (UTC)

Lunar Eclipse - yet another q?

Im sure mankind has been fascinated with eclipses and there are many questions which have been asked about eclipses and many more questions might continue to asked. Please excuse me even if my question sounds trivial... I was watching last night's lunar eclipse and I got a brilliant view from the comfort of my living room sofa which has these huge french windows and right in front of me I could see the entire eclipse... Though Im a doctor and belive most of the scintific explanations behind all actions in our life, I dont blindly follow what science says. I always try to reason it out rather than take it as a dictum. What I noticed was just by the side of the moon on all sides I could see the starry sky very brilliantly and only the moon was obscured by this grayish reddish cape. If the lunar eclipse really does happen because of earths shadow covering the moon, then why is it during eclipse several stars just adjacent to the moon are very clearly visible ( the stars being so faint and distant) yet the much more closer, much more bigger and brigter moon was totally hidden and appeared like to be a mere silhouette? In other words, if the shadow of earth is so big and strong to blank out and virtually snuff out the moon, shudnt the entire area of earths shadow black out the stars and planets too in its path?--Fragrantforever 10:40, 16 June 2011 (UTC) — Preceding unsigned comment added by Fragrantforever (talk • contribs)

Cause the stars emit their own light and the moon doesn't -- the Earth's shadow blocks the Sun's light from reaching the moon, not the light reflected from the moon to the earth. 67.169.177.176 (talk) 10:55, 16 June 2011 (UTC)

It is either impossible to have eclispe with other planets. The shadow of the earth is cone shapped as you can see in the article lunar eclipse. Only very close objects (like the moon) can enter this shadow cone. This shadow cone is rougthly 5 times longer as the distance between earth and moon--Franssoua (talk) 10:59, 16 June 2011 (UTC)

Actually, the umbra just barely touches Earth, and sometimes it doesn't reach, forming an annular eclipse. Now the transit of Mercury or transit of Venus also produces an "annular eclipse" of sorts - but you need good equipment to be able to see the tiny shadow against the Sun. The other planets never come between Earth and the Sun, but Earth comes between the Sun and them, and indeed its shadow does affect them in the sense that the transit of Earth is visible from their perspective, again as just a tiny black dot crossing the Sun. (I don't think even machines have observed one from the surface of another planet, but they have from space) Wnt (talk) 15:10, 16 June 2011 (UTC)

Wnt - you are confusing solar eclipses with lunar eclipses. The length of the Earth's umbra is about 3.5 times the distance to the Moon, as can be seen from geometry and similar triangles:

${\text{Length of Earths umbra}}={\frac {\text{Radius of Earth}}{\text{Radius of Sun}}}\times 1{\text{ AU}}={\frac {1}{109}}{\text{ AU}}$

${\text{Radius of Moons orbit}}=0.00257{\text{ AU}}$

${\frac {\text{Length of Earths umbra}}{\text{Radius of Moons orbit}}}={\frac {1}{109\times 0.00257}}\approx 3.57$

Lunar eclipses can be total, partial or penumbral but they are never annular. Gandalf61 (talk) 15:42, 16 June 2011 (UTC)

You're right - I was talking almost entirely about solar eclipses - not sure how I missed the obvious "lunar" up there! Wnt (talk) 16:59, 16 June 2011 (UTC)

You don't need good equipment to see a transit of Venus. I observed the last one with just a pair of binoculars and a piece of paper (by projecting onto the paper - hopefully I don't need to say it, but you should never look at the sun through binoculars). It would have helped if I'd had a tripod or something to hold the binoculars steady, but I could easily see the silhouette of Venus even though it was shaking all over the place. Mercury is a little more difficult - I saw the 2003 transit, but that was through a small (filtered) telescope. --Tango (talk) 18:15, 16 June 2011 (UTC)

Foil wrapped for freshess

Do foil wrappers, crisp packets etc actually "lock in" freshness better than regular, properly sealed plastic could? Or was/is it just a ploy? --129.215.5.255 (talk) 11:06, 16 June 2011 (UTC)

Foil would reflect some light and heat. This could make a difference. Zzubnik (talk) 11:23, 16 June 2011 (UTC)

The plastics used for food packaging, like PET, are somewhat permeable to gasses, liquids, and UV radiation. Metallised film treatments dramatically lower this permeability. This allows for longer shelf-life and less spoilage (but no so much from sealing "freshness" in, but keeping stuff out). -- Finlay McWalter ☻ Talk 11:27, 16 June 2011 (UTC)

Solubility and pH

Hello. The solubility of Mg(OH)₂ in a particular buffer is 0.65 g/L. The K_sp of this salt is 1.8×10^-11. What must be the pH of the buffer? If the buffer does not react with Mg²⁺ ions, [OH^-] = 4.02×10^-5. However, for each mole of Mg(OH)₂ dissolved, two moles of OH^- ions dissociate. Assuming 1 L of volume, the buffer reacts with (2.23×10^-2 - 4.02×10^-5) moles of OH^- ions. So, the buffer pH should be 1.65. The answer key claims 9.60. What have I done wrong? Thanks in advance. --Mayfare (talk) 15:35, 16 June 2011 (UTC)

You have made this WAY more complicated than it has to be. All you need to do is find the concentration of the OH- at the given solubility, and find out what pH produces that concentration of OH- Consider the following:

If [OH-] = 4.02E-5, and pOH = -log [OH-], then pOH = 4.40

Since pH = 14-pOH, then pH = 14-4.40 = 9.60

--Jayron32 15:53, 16 June 2011 (UTC)

About the Brain

I might have this confused so any help is appreciated. Now, from what I understand, our memories both short term and long term are kept in cells that travel throughout the brain matter or neurons. But what about the things that make up our personality or if we are good at science or math are they also kept in cells? Are the neurons and the brain matter just the keepers of the cells what they are in or on? And when we have an accident to the head or if people do drugs for years and they lose brain cells (or change in personality, since change in brain chemicals) or die off naturally the brain itself remains the same, does it not, it is just the cells or the chemicals coming in and out that change? — Preceding unsigned comment added by 71.137.252.216 (talk) 18:42, 16 June 2011 (UTC)

It is a hard question to answer. You may want to start exploring things neuroscience topics in general, to get at the biology end of it, as well as some philosophical ideas, the Hard problem of consciousness and Phenomenology. From the "brain structure" end, check out Behavioral neuroscience and Cognitive neuroscience. Personality_psychology#Biopsychological_theories has a little bit as well. Most of what we call "personality" seems to have its origins in the Prefrontal cortex and the Amygdala. --Jayron32 18:58, 16 June 2011 (UTC)

I wouldn't say that memories are kept in cells that travel through neurons. They are kept in the neurons and in the synapses that connect them. Electric signals travel through neurons carrying information. Dauto (talk) 19:06, 16 June 2011 (UTC)

If it helps, you could think of the cells and the way they're connected as the brain's "hardware", and the electric signals and brain chemicals as the "software". Both are important factors that determine your personality and many other things. And yes, any kind of brain damage will affect both of these. 67.169.177.176 (talk) 20:30, 16 June 2011 (UTC)

Onychogalea

Why Onychogalea evolved a nail tail while other macropods don't?--188.147.5.203 (talk) 18:48, 16 June 2011 (UTC)

Evolution doesn't have "whys" beyond "It happened randomly and the trait didn't cause the individuals that had it die off too fast to pass the trait on to their young". --Jayron32 19:01, 16 June 2011 (UTC)

Why do people in England speak English while other Europeans don't? Dauto (talk) 19:10, 16 June 2011 (UTC)

Jayron32's answer means that the trait is not so deleterious that it would quickly vanish from the population. That is indeed the minimum we can safely infer about the (stable) presence of a certain trait in a certain species. However, the nail-tail trait could also be adaptive, meaning that it "enables or enhances the probability of that organism surviving and reproducing"(emphasis mine). See also Adaptation#Adaptedness_and_fitness and fitness_(biology). Determining what category this specific trait falls into would require a dedicated research project. SemanticMantis (talk) 19:51, 16 June 2011 (UTC)

INFORMATION ON CAPTAFOL

Wikipedia article on captafol says it is no longer used in the U.S. but is used on a variety of crops, which are listed. My question is: Which of these crops are imported into the U.S., in what quantity, and are any credible individuals or government agencies (notice lack of the word "credible" here) monitoring deaths and ill health effects from these captafol-infested products? I am grateful to everyone with an appropriate answer or other information. Thank you. 75.6.40.146 (talk) 19:54, 16 June 2011 (UTC)

Scratched CD

I have Flight Sim 2004 installed on my computer, which I really enjoy playing on weekends (I know, FSX is the current version, but I really love the Lockheed Vega). This software comes on 4 CD-ROMs, of which CD-ROM #4 has to be inserted into the CD-ROM drive when playing. Last night, I noticed that the #4 CD-ROM has many small scratches on it -- by small, I mean so small that most of them can only be seen under a bright light, but there are many of them. Be that as it may, they do NOT seem to be affecting the gameplay in any way. My question is, do you think this will become a problem if I have to reinstall the program from the CDs for any reason? Thanks in advance! 67.169.177.176 (talk) 20:26, 16 June 2011 (UTC)

Note that CD-ROMs use very good Error-correcting_codes, so that the information can be retrieved even after some data loss or corruption. I don't know whether the game is actually reading important data from the disc as you play, or if it just checks a few bits to make sure you have the disc (i.e. for copy protection purposes). If it's the former, then you are probably fine. SemanticMantis (talk) 20:36, 16 June 2011 (UTC)

Clear fluid where a scab is ripped off

Sometimes when a scab gets ripped off, the body secretes a clear fluid over the wounded area. What is this substance most likely? 20.137.18.50 (talk) 20:30, 16 June 2011 (UTC)

I think some kind of lymph or intercellular fluid. FWIW 67.169.177.176 (talk) 20:32, 16 June 2011 (UTC)

The general term for clearish fluids in the body is Serous fluid, and its literally all over the place. If it isn't inside of either cells OR your blood vessels, it is often called Interstitial fluid. The stuff you see when the scab is picked, which is clear, is just serous fluid. If it is yellow and thick and has an odor, then it may be pus and you should see a doctor, because that is a sign of an infection. Indeed, if there is any fluid coming out of your body which you cannot identify, you should see a doctor. --Jayron32 20:48, 16 June 2011 (UTC)

Weatherproofing steel, black powder

Hi all,

I recently bought tubes of mild steel directly from a factory. The tubes are coated in some kind of black powder or oil. It makes your hands black when handling them, but doesn't come off the metal easily -- no handprints after handling or anything.

1. What is this?
2. If I want to weatherproof using RustOleum or something, should I remove it?

Thanks! — Sam 166.186.171.172 (talk) 20:43, 16 June 2011 (UTC)

Measure rainfall

Hello all. For the next month or so school is out and the summer classes don't start until mid-July so I'm going to be on vacation. I'm interested to know how much rain falls during the next three or so weeks, and instead of just looking it up on any reputable meteorological site I'd like to take my own measurements. However, I don't want to spend any money on this, so this should be using only the equipment of a well-stocked household. All my friends are going on vacation (or back home) too so I can't rely on anyone to come and take readings every day, which means I'll have to find some way to prevent or compensate for evaporation. I will also need to prevent wind from blowing the collecting thing over. How could I do this? thanks. 72.128.95.0 (talk) 20:50, 16 June 2011 (UTC)

You could cut a 2-liter bottle in two and flip the top-half upside down in the bottom half, forming a funnel. This would greatly lower loss through evaporation. You could easily weight the bottom with the addition of rocks. (That would increase the apparent waterlevel, but that's not an issue as you can always take the rocks out later or pour into a new container.) The wider your collector the more accurate this method will be. NB: I'm not sure if you're hoping to collect daily totals. This method would obviously not work for that. — Sam 166.186.171.173 (talk) 20:57, 16 June 2011 (UTC)

Bioelectromagnetism Burn Marks

Last bracelet returned

Currently worn bracelet

Microwaves and other radiofrequency radiations of the electromagnetic spectrum can have highly predictable effects on behavior at modest and even low levels of irradiation. 'D.R. JUSTESEN'

I bring this up as a rational possibility to my question, thinking possible cause is some unseen by the naked eye electrical current passing through the human body.

Question: What possible cause(s) for these burn holes on hologram stickers?

I'm on my 5th Power Balance bracelet. I send back for replacement after these burn marks get pretty large. The difference between these two picture examples, the center burn hole, I wore bracelet all the time. I was thinking maybe the shower could amplify electrofields, this is just speculation. Living on the penthouse of my downtown apartment; possible higher RF than on the 5th floor where I moved for the past 2 months (see current pic, with circular ring).

I read article on the RMIT University findings on Holographic technology wristbands. Bioelectric effects in regards to both bioaccumulation & environment could change outcome making RMIT case study ineffective. For what explanation would these burn holes be? I think many factors could be at play here. My brother wore these [[Antistatic wrist strap| antistatic ankle straps] when working on semiconductors to ground him as to not zap the materials he assembled. Enter the myth of Antaeus who derives his power from the earth, he loses his strength when feet not connected to the ground.

A few Questionables:

• My clerical workplace has raised floor, I sit through traffic--disconnected to the earth, and my living space is also in the sky.
• Could even the material the soles of our shoes be a factor in disconnecting the natural electrical current?
• Could another factor be minerals in our water and foodstuffs? An example, I drank a very large bottle of Jermuk mineral water that I purchased from an Armenian market. At break, went for a walk around the block and in the bright sunlight I felt these tinglys all over my body. The SUN being that it is a very large magnet could charge these nanominerals in the body?
• Maybe high RF from powerlines.
• Maybe the 3 Cell towers directly above us at our workplace.
• WIFI
• Cell phone
• Bluetooth
• Monitors
• Microwaves from home appliances

Note: these Power Balance holograms have no openings in silicon bracelet, the sticker being embedded in center of silicon. Thoughts anyone? --i am the kwisatz haderach (talk) 21:02, 16 June 2011 (UTC)