Science desk
< October 11	<< Sep \| October \| Nov >>	October 13 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

October 12

menstrual taboo

Many cultures and religions have taboos against sexual intercourse while a woman is menstruating. Are there any physical or physiologial reasons why this should not occur? Are there any benefits to sexual intercourse during the menstrual cycle? 99.250.117.26 (talk) 00:09, 12 October 2011 (UTC)[reply]

Blood, contraception. μηδείς (talk) 00:30, 12 October 2011 (UTC)[reply]

Are there any benefits to sexual intercourse during the menstrual cycle? Because otherwise you'd have to wait 30 years and never have any children? (Well, there are ways of preventing menstruation, but only recently in human history, and they still prevent having children). I think you're confusing the menstrual cycle with menstruation. --Colapeninsula (talk) 09:13, 12 October 2011 (UTC)[reply]

Perhaps I am confusing the two but I was wondering if there were any benefits (to the woman) in engaging in sexual intercourse while menstruating. I read the wiki article but this didn't answer my question. 99.250.117.26 (talk) 16:58, 12 October 2011 (UTC)[reply]

In PMID 20577749 it says it's not likely to be unhealthy, just messy. Dualus (talk) 17:55, 12 October 2011 (UTC)[reply]

Against: blood. For: contraception. μηδείς (talk) 00:30, 12 October 2011 (UTC)[reply]

There is little blood there, μηδείς, contrary to popular belief. It's actually the uterine lining. And you are also wrong about contraception. While many women may be more likely to become pregnant mid-cycle, the chance of conceiving during menstruation may be higher than previously thought. Another fact to know: Sperm can live up to 5 days in a woman's body. Quest09 (talk) 23:04, 12 October 2011 (UTC)[reply]

Well, yes, I know it's not all blood but that's what people call it and of course it is not a foolproof method of contraception but I am not the only person to have taken advantage of it. μηδείς (talk) 01:29, 13 October 2011 (UTC)[reply]

It's almost no blood there, just 35 milliliters during a monthly menstrual period, it doesn't matter "what people call it." And it's certainly not a contraception method. The high failure rate of calendar-based contraception is very well-known. Quest09 (talk) 14:55, 13 October 2011 (UTC)[reply]

Granted, but still better then nothing. Googlemeister (talk) 15:21, 13 October 2011 (UTC)[reply]

Yes, checking the most fertile days to avoid pregnancy is better than nothing, but if you do it all the time, it equals nothing. Quest09 (talk) 16:03, 13 October 2011 (UTC)[reply]

See calendar-based contraceptive methods. ~AH1 ^(discuss!) 23:29, 14 October 2011 (UTC)[reply]

Aboriginal North Americans and alcohol

Is it true or accurate that Native North Americans have something "physiological" about them that results in an inability (or significantly reduced ability) to metabolize alcohol in their bodies as compared, say, to Whites? Or, is this more of a myth and that the apparent "inability of Indians to handle their liquor" impacted more by stereotyping and cultural oppression? 99.250.117.26 (talk) 00:33, 12 October 2011 (UTC)[reply]

There are some genetic factors (see Alcohol_tolerance#Alcohol_tolerance_in_different_ethnic_groups), but a lot of it is social-cultural as well. They are mutually reinforcing (for the negative) in this case — rampant poverty plus genetic factors begets more rampant poverty and so on. --Mr.98 (talk) 00:58, 12 October 2011 (UTC)[reply]

Decades ago the claim was frequently made that Aboriginal Australians had a similar problem metabolising alcohol. That dogma seems to have now faded in favour of the view that the problem is more related to generational disadvantage. HiLo48 (talk) 01:44, 12 October 2011 (UTC)[reply]

You may find this article interesting, regarding the theory that response to alcohol is culturally mediated rather than physically mediated. --TammyMoet (talk) 09:41, 12 October 2011 (UTC)[reply]

I would just emphasize again that it's always a dynamic between the two. It's never an "either/or" situation — it's a "both" situation. --Mr.98 (talk) 11:57, 12 October 2011 (UTC)[reply]

See alcohol flush reaction, acetaldehyde and acetaldehyde dehydrogenase. ~AH1 ^(discuss!) 23:27, 14 October 2011 (UTC)[reply]

About the alleged FTL neutrinos

What if they only exhibit this FTL behavior some of the time. Like... I'm just making this up, but lets say the neutrinos passed through holes in space time that open up only very rarely and the last experiment just happened to catch it. But if they were to repeat the experiment, they notice no FTL behavior because the holes didn't appear that time. Isn't something like that possible? That an experiment just happens to catch a rare occurrence that isn't likely to be repeated? ScienceApe (talk) 03:30, 12 October 2011 (UTC)[reply]

That would be even more weird than if we were to find that they always travel at the same FTL speed. And more unlikely. --Lgriot (talk) 07:56, 12 October 2011 (UTC)[reply]

Also for your information the CERN has repeated the test hundreds of times already. So it is not a rare occurence, the results were consistent. --Lgriot (talk) 07:58, 12 October 2011 (UTC)[reply]

Hm. Sounds like something for the Journal of Irreproducible Results. Comet Tuttle (talk) 17:12, 12 October 2011 (UTC)[reply]

As Lgriot stated, the faster-than-light measurement has been performed repeatedly and the same speed is measured each time. What he didn't state is that the people performing the experiment do not consider this evidence of faster-than-light speed. They consider it an error in the accepted method of measuring the speed of near-light-speed particles - and published their findings with the purpose of fixing the measurement error. It was a bunch of newspaper reporters who spun the story around to claim that the neutrinos were traveling faster than light. -- kainaw ™ 17:22, 12 October 2011 (UTC)[reply]

It may be more fair to say they weren't sure it was an error when they published the results. Have they identified the most likely candidate sources of error? Dualus (talk) 17:57, 12 October 2011 (UTC)[reply]

The authors of the original paper (the ones who made the measurement) were certain there was an error. They assumed it had to do with relativity itself. Currently, many scientists have been pointing out that while they corrected for the difference in time between the high-speed neutrinos and Earth itself, they didn't correct for the difference in speed between the GPS satellites used as clocks and Earth (and they didn't even consider the difference in speed between the neutrinos and the satellites). There has already been one paper published that takes all that into account and the speed of the neutrinos is slightly less than the speed of light. -- kainaw ™ 00:46, 17 October 2011 (UTC)[reply]

My understanding is it has been attributed to a difference in the mass of underlying rock, causing a slight difference in gravity to have caused a relativistic error between clocks at the two locations. See here. μηδείς (talk) 20:39, 12 October 2011 (UTC)[reply]

The article does say too that the OPERA scientists apparently plan to rebut the lone paper making that attribution. --Modocc (talk) 07:00, 13 October 2011 (UTC)[reply]

Just maybe now, the Doctor has parked his or her Tardis near the CERN facilities to investigate innocuous events taking place there. No doubt he or she will also help the OPERA team reason out the results of their experiment. But instead of correctly attributing it to the Tardis's temporary signature, they end up attributing the results to some other concurrent events which will no doubt satisfy them immensely. Certainly, these current events will be elaborated on in a future production of an awesome, and amazing, historical story. Of course, the stories that the Tardis was actually directly involved will be referred to as fiction and not fact per wp:TRUTH. --Modocc (talk) 19:23, 13 October 2011 (UTC)[reply]

See also tachyons. The "tachyonic" nature of neutrinos was predicted in 1985. ~AH1 ^(discuss!) 23:24, 14 October 2011 (UTC)[reply]

Knappable stone in Southwestern CT

So I am wondering, what kinds of stone that are good as cores for flint-knapping (ones heavy in silicates) can be found in the area of Fairfield County, CT, and where in the county can they be found? Westchester, NY is okay as well. I knapped some basalt earlier today and am eager to create some more stone tools. I know I can find quartz, but I'm looking for flint and chert, maybe something even better like obsidian. Sir William Matthew Flinders Petrie | ^{Say Shalom!} 14 Tishrei 5772 03:34, 12 October 2011 (UTC)[reply]

Is this map: [1] helpful? It would appear that most of SW connecticut is of oceanic schist and gneiss deposits; I'm not sure these provide the sort of knappable stones you're looking for. There appears to be a band of rocks running along the CT/NY border through Danbury (the blue band on the map) and possibly down the I-684 corridor in NY which has some quartzite, which Wikipedia's article seems to indicate can be used as a substitute for flint. That may be your best shot. --Jayron32 05:20, 12 October 2011 (UTC)[reply]

Ah. good map. No, I'm afraid not. :( Schist tends to flake in a manner similar to baklava (except not as tasty), gneiss is too hard. Quarzite would make a good hammerstone though.

I think I should order some flint. Stupid glacier messed up the geology and likely pushed all the good stuff into that terminal morraine of its. ._. Wait just a moment... Great Captain Island is a recessional morraine? This report from the Audobon doesn't say much about the types of rocks. [2] :( Sir William Matthew Flinders Petrie | ^{Say Shalom!} 15 Tishrei 5772 03:46, 13 October 2011 (UTC)[reply]

Power Input vs. Voltage Output.

Hello.

If I have a simple circuit as shown below:

Power in--------Resistor--------------------Voltage Out

And I can determine the power coming in to the circuit but only the voltage coming out ( I don't know the resistance across the circuit), what sort of relationship can I expect between the power input and the voltage output?

114.77.39.141 (talk) 04:50, 12 October 2011 (UTC)[reply]

If you know the power P consumed by a resistor and the voltage V across the resistor, you can compute the resistor's resistance as

R={\frac {V^{2}}{P}}

. That's a variation of the equation

P={\frac {V^{2}}{R}}

listed at Electric power#Direct current. Red Act (talk) 06:18, 12 October 2011 (UTC)[reply]

... and please note that, as mentioned by Red Act, the voltage is measured across. The concept of "Voltage out" does not make sense for a resistor, and the power is dissipated by the resistor (mainly turned to heat). Dbfirs 08:12, 12 October 2011 (UTC)[reply]

Ok what about in the case where the signal is AC, and the relationship between V, I, P and R is not linear; are there any assumptions/relationships I can assume in a case like that? 114.77.39.141 (talk) 09:01, 12 October 2011 (UTC)[reply]

This makes no difference because the relationship is linear at any instant, and for a pure resistance there is no phase difference between the voltage and current. You can just use the RMS values as if they were DC. (Are you sure you are asking about a passive resistance? The phrasing of your question suggests that you might have some sort of semiconductor "black box" where relationships are not linear.) Dbfirs 14:08, 12 October 2011 (UTC)[reply]

The 'resistor' is actually a dead cochlea, so I assume due to a lot of changes in the extracellular environment, which leads to non linear changes in resistance.114.77.39.141 (talk) 22:06, 12 October 2011 (UTC)[reply]

I think a dead cochlea would operate as a linear (Ohmic) device over a fairly broad range of operating conditions, because there isn't much of a reason why it wouldn't. The current going through a dead cochlea doesn't go through a lot of loops, so there wouldn't be much inductance, there are no thin dielectrics involved, so there wouldn't be much capacitance, there are no major crystalline structures involved, so there wouldn't be nonlinearities due to band gaps, and the tissue is dead, so there wouldn't be any neural action potentials involved. There will be nonlinearities at very high voltages or frequencies, but otherwise, I think Ohm's law should hold quite well. Red Act (talk) 00:32, 13 October 2011 (UTC)[reply]

Agreed, though, of course, if you are causing a large power dissipation then the heat produced will cause physical and chemical changes that will change the resistance, probably permanently. Dbfirs 05:45, 13 October 2011 (UTC)[reply]

This has been very useful, particularity114.77.39.141 (talk) 10:44, 14 October 2011 (UTC) the last two comments. Thanks very much guys =)[reply]

Surrogate instead of abortion

Lets say a mother doesn't want the baby, but the father does. Is it possible to remove the embryo and grow it in a surrogate mother? ScienceApe (talk) 05:02, 12 October 2011 (UTC)[reply]

It would depend a lot on your legal jurisdiction, and on how good your lawyer was. --Jayron32 05:06, 12 October 2011 (UTC)[reply]

...not to mention how good your surgeon is! Richard Avery (talk) 07:02, 12 October 2011 (UTC)[reply]

Plural surgeons in the distant future, if ever. Dualus (talk) 18:02, 12 October 2011 (UTC)[reply]

Embryo#Viability says "Current medical technology does not allow an embryo to be transplanted from the uterus of one woman to that of another." --Colapeninsula (talk) 09:21, 12 October 2011 (UTC)[reply]

(ec) Short answer: no.

Long answer: to answer your question, I need to break it into separate questions:

Question 1: Is it possible to detect pregnancy before the embryo has implanted, then remove the embryo and insert it into another woman's uterus, and have it implant there?

Answer: Implantation (human embryo) occurs about 9 days after ovulation (6-12 days, according to our article). Pregnancy can be detected as early as 6 days after ovulation. Pregnancy tests work by detecting Human chorionic gonadotropin, which is produced by the developing embryo after conception, and later by the placenta. Therefore, theoretically, there may be a window of a day or two between the earliest possible detection of pregnancy and the implantation of the embryo. The problem, then, would be the localisation and successful harvesting of the embryo on its way down the fallopian tubes (or in the uterine cavity just before implantation). To my knowledge (and after googling high-resolution ultrasound), localizing an embryo at this stage is not within reach of current ultrasound technology. The eggs that are harvested for IVF are contained in larger structures (follicles) in the ovaries, and what is harvested from there is a fluid, from which eggs are isolated under a microscope. One might perhaps attempt something similar, like infusing a suitable liquid intraperitoneally near the opening of the fallopian tubes, and collecting fluid from the uterus, trying to flush the embryo into a container. This is definitely sci-fi, and risky with respect to future pregnancy. Another possibility, would be to remove the uterus and fallopian tubes, and carefully under a microscope dissect the path that the fertilised embryo travels, in an environment with controlled temperature and humidity. Such a procedure would of course rule out future pregnancies. I would rate the chances of success for both strategies as slim. Harvesting fertilized eggs using the second method has been successfully performed in mice [3], but the mice were killed in the process.

Question 2 Is it possible to remove an embryo that has implanted, and transplant it to another woman's uterus, and let the pregnancy continue there?

Answer: This is definitely science fiction. As the Implantation (human embryo) article explains, implantation involves a complex interplay between maternal and fetal tissues. To attempt such a transplant, you would need to have the surrogate mother's uterus somehow prepared to take over the function of the biological mother's uterus, at a stage where the function of the latter has been strongly modified by the embryo, through processes that are not fully understood, and then accept a graft consisting of an embryo and tissues from the biological mother. There is no way that this is remotely possible with current knowledge and technology.

Question 3: Is it possible to remove a pregnant woman's uterus, and transplant it into another woman, allowing the pregnancy to continue there?

Answer: According to our article uterus transplant, there has been performed a few attempts at transplantation of human (non-pregnant) uterus, and it is debatable whether any of them can be considered successful. None have resulted in pregnancy, and one caused the death of the recipient. However, pregnancy in a transplanted uterus has been achieved in immunosuppressed sheep, so human uterus transplantation may at some time in the future become an option for women who lack a functioning uterus. Transplanting a pregnant uterus is a different story. You would (at the very least) need to somehow replace the function of the Corpus luteum. Conclusion: This option is also out of reach of current technology. --NorwegianBlue^talk 09:37, 12 October 2011 (UTC)[reply]

See axolotl tank. μηδείς (talk) 20:35, 12 October 2011 (UTC)[reply]

The axolotl tank mentioned above is a semi-artificial uterus from Frank Herbert's science fiction series Dune. While that is not a particularly useful answer to the OP's question, our artificial uterus article (which clearly states that it deals with a "theoretical device") may be of interest. -- 110.49.122.25 (talk) 06:19, 13 October 2011 (UTC)[reply]

Depends what you mean by helpful. It was already explained that the idea is currently science fiction. Herbert explored one set of social dynamics which might lead to such a scenario. μηδείς (talk) 02:02, 14 October 2011 (UTC)[reply]

How long does it take for acquired immunity to form

Hi. The title question pretty much says it all. If a human being were to be infected by a mild-to-moderate pathogen he's never encounted before, how long would it take him to acquire immunity to that given pathogen? Or does it depend on the pathogen itself? Thanks. Leptictidium (mt) 09:49, 12 October 2011 (UTC)[reply]

It depends on the pathogen and, importantly, on whether he's been exposed to similar pathogens before. I think it's usually on the scale of a few days, though. --Tango (talk) 12:12, 12 October 2011 (UTC)[reply]

A textbook answer would be that IgM antibodies develop in about three weeks, and that IgG antibodies appear several weeks later. On a second encounter with the antigen, when immunity has been aquired, the response is much faster (IgG production within less than a week). Take a look at the diagram that shows antibody production after hepatitis B infection. Anti-HBs antibodies appear after several months. These are the antibodies that are protective against future infection. --NorwegianBlue^talk 00:07, 13 October 2011 (UTC)[reply]

See acquired immunity. The rates will depend on the virus or bacterium, as compare for example Hepatitis and the chickenpox virus. ~AH1 ^(discuss!) 23:18, 14 October 2011 (UTC)[reply]

Sun seen from space

If we were in space (outside any effect of scattering), and looked at sky while the sun were in the middle, how would it look like and can we see the stars around as in the night? Are there any photos from NASA that can explain this?--Almuhammedi (talk) 12:37, 12 October 2011 (UTC)[reply]

Well, without some sort of protection, you would be blinded almost instantaneously by the luminous intensity, and your retinas will be permanently scarred by a combination of the full spectrum, including but not limited to gamma, x-ray, and ultraviolet. It would look much the same as it does from the ground, except that you would have a much sharper image - the sun would contrast much more on the black background of space. You would see the stars much more clearly than at night as viewed from the ground. The sun would be surrounded by the faint glow imparted by solar radiation. Plasmic Physics (talk) 13:10, 12 October 2011 (UTC)[reply]

I'm not so sure about the scarring. The atmosphere on a clear day only reduces luminous intensity by about 30%. So, I would suggest that the effects and perceptions of looking at the sun from space are likely to be pretty similar to glancing at the sun from Earth on a clear day. In other words, temporarily blinding and painful with afterimages, but that the instinct would still be to close your eyes and look away before doing permanent damage. (Thankfully brief glances of the sun cause no permanent damage, or everyone who works outside would be blind by now.) Yes there is a broader spectrum in unfiltered sunlight, but there isn't much total power in x-rays and such compared to visible light, and I would be surprised if that makes any difference in the brief interval before one would close your eyes and look away. I agree that the sun would appear as a sharper image on a black background. If you block out the sun (so your eyes can adjust to darker seeing conditions), then one should be able to see stars whose position in the sky is not too far from the sun. Dragons flight (talk) 16:15, 12 October 2011 (UTC)[reply]

Here is a photo although it shows a lot of lens flare which is an artefact of the camera lens. --Colapeninsula (talk) 16:19, 12 October 2011 (UTC)[reply]

The colour will also be slightly different. Seen through the atmosphere, a lot of the blue light is removed by Rayleigh scattering (and makes the rest of the sky blue). That's not the case in space. That should make the sun whiter, rather than it being slightly yellow as it is through the atmosphere. The yellowness isn't really noticeable, though, since it's too bright - it's like an overexposed photograph, it just appears white - so you wouldn't really tell the difference with the naked eye, you would need a spectrograph. --Tango (talk) 20:00, 12 October 2011 (UTC)[reply]

Water on Earth and the physical properties of water in ocean

Garrison writes that "much more water is trapped within Earth's hot interior than exists in its ocean and atmosphere". Where is this water (in mantle?) and how much of it is there? Also, he gives some figures such as average depth of ocean to be 3796 m, average temp. of seawater to be 3.9 deg. celcius and mass of ocean 1.41 billion billion metric tons. How do scientists manage to figure out the average depth (by mapping the whole sea floor?), temp and mass (which will be a function of salinity)? Thanks. - DSachan (talk) 13:17, 12 October 2011 (UTC)[reply]

I would say that average depth is a function of volume, and surface area, once you know those two things you're set. Volume is based on density and mass. Plasmic Physics (talk) 13:28, 12 October 2011 (UTC)[reply]

NOAA has mapped the entire sea floor for depth at low resolution (at least 1 data point per 4 square nautical miles), which would be sufficient for a pretty good estimate. Googlemeister (talk) 14:20, 12 October 2011 (UTC)[reply]

Right, you can see it all using Google Earth. Regarding the mantle, the water is essentially dissolved in the rock. Looie496 (talk) 14:42, 12 October 2011 (UTC)[reply]

"Dissolved" is in the ballpark, but it isn't the exact right term. The water is part of rocks as Water of crystallization. See especially the article Mineral hydration, which deals mostly with crustal minerals, but the chemistry should work in any rock... --Jayron32 15:20, 12 October 2011 (UTC)[reply]

If the OP is interested in how satellite altimetry is used to build the predicted water depth datasets, NOAA have quite a nice page here explaining the technique. We also have an article about GEBCO who generate the "GEBCO_08 Grid" bathymetric dataset at 30arc-second intervals. Sean.hoyland - talk 17:05, 12 October 2011 (UTC)[reply]

From LiveScience - Huge 'Ocean' Discovered Inside Earth. ~AH1 ^(discuss!) 23:09, 14 October 2011 (UTC)[reply]

Species identifcation (flower)

To aid a rename request, is the specfic tulip concerned identifiable in the image linked? Sfan00 IMG (talk) 20:31, 12 October 2011 (UTC)[reply]

Possibly Tulipa praestans 'Fusilier'?-- Obsidi♠n Soul 01:14, 13 October 2011 (UTC)[reply]

I added "flower" to the title to distinguish from your other "Species identification" questions (but I kept your typo in). StuRat (talk) 14:41, 13 October 2011 (UTC) [reply]

Can a Chihuahua survive in the wild?

Topic says it all. ScienceApe (talk) 16:05, 12 October 2011 (UTC)[reply]

It would depend where. A chihuahua would have to scavenge for food rather than hunting: it could eat carrion and whatever else it could find (roadkill, other animals' leftovers, food from bins, food left for other pets). It would be vulnerable to larger carnivores, if there were any - foxes are reportedly unlikely to kill even small dogs, but wolves or bears could. If there was a good food source (maybe in a city) and no larger carnivores it could survive for a while, but in less hospitable environments it would be in trouble. I'm not sure how it would fare in winter, but cold would certainly be a problem. --Colapeninsula (talk) 16:28, 12 October 2011 (UTC)[reply]

I read a Scientific American article that said that if all humans disappeared, then dogs would have some chance, but it was basically how close to a wolf they remained (a number of other pets, like cats, would apparently not survive past human food sources going). I don't think a Chihuahua ranks highly on the "wolf" scale. Grandiose (me, talk, contribs) 16:48, 12 October 2011 (UTC)[reply]

Life After People is the National Geographic speculation on what would happen over the decades. Comet Tuttle (talk) 17:04, 12 October 2011 (UTC)[reply]

I don't know why it couldn't hunt - it could hunt and kill small rodents. It would probably survive on a combination of hunting and scavenging, like wild dogs and wolves do. thx1138 (talk) 17:53, 12 October 2011 (UTC)[reply]

Dingos are basically stray dogs that have learned to live in the wild and survived for 100's of generations, so they are pretty strong evidence that at least some dogs could survive without humans. I expect a lot of pets would die, but it only takes a few to survive to be able to keep the species going - I'm sure a few cats would be able to cope, strays aren't that uncommon and they don't just rely on humans leaving out food for them. --Tango (talk) 20:05, 12 October 2011 (UTC)[reply]

Dingos, which are pretty close to wolves, are a far cry away from chihuahuas. Quest09 (talk) 16:24, 13 October 2011 (UTC)[reply]

See esp. feral cat, feral dog. I suspect chihuahuas would be at a particular disadvantage, though, given their tiny size and their not too great reputation for smarts. Like many dogs at the extremes, they are heavily inbred and have a number of very disadvantageous features. --Mr.98 (talk) 21:53, 12 October 2011 (UTC)[reply]

I'd agree with Mr. 98 and say that chihuahuas would have little chance without being fed by humans. In a situation where pet dogs where forced to fend for themselves in a depopulated city, chihuahuas would be out competed by smarter larger dogs (even large and intelligent breeds would probably struggle to survive). If you just put a chihuahua out in the woods where no one would take it in it would certainly die. They don't have much of a hunting instinct and in the natural environment there are already predators well adapted to most niches who wouldn't leave much for a lone chihuahua. --Daniel 22:08, 12 October 2011 (UTC)[reply]

Just as an illustration, chihuahuas and house cats are probably in about the same size/prey class. My money would be on the house cats to win in that little evolutionary niche competition. (There are also gobs more house cats than chihuahuas, so they'd have an early advantage.) --Mr.98 (talk) 11:54, 13 October 2011 (UTC)[reply]

One point that all seem to be missing is that dogs can form packs. The question is if chihuahuas would be accepted in one with other, bigger dogs and in what kind of wild environment would this pack have to survive. Quest09 (talk) 12:29, 13 October 2011 (UTC)[reply]

Electron configurations

I'm doing a WebAssign homework assignment for chemistry, and on a question asking me to write electron configurations for ions it says that "[Ar] 4s² 3d⁶" for Ni²⁺ and "[Ar] 4s² 3d⁷" for Cu²⁺ are wrong. These are what my chemistry book says the electron configurations for two less electrons than Nickel and Copper are, so I'm completely lost as to why it's saying they're wrong. Any help? Ks0stm ^{(T•C•G•E)} 19:58, 12 October 2011 (UTC)[reply]

We have a fairly detailed electron configuration article, including a section entitled "Ionization of the transition metals" that may be of interest. DMacks (talk) 20:32, 12 October 2011 (UTC)[reply]

That fixed it. I didn't think to look in the electron configuration article for such specific information; I was looking in the elements' articles. Thanks, Ks0stm ^{(T•C•G•E)} 20:46, 12 October 2011 (UTC)[reply]

Species identification (beetle)

To aid a rename request, anyone able to identify the species concerned? Sfan00 IMG (talk) 20:21, 12 October 2011 (UTC)[reply]

I know location is often a good way to narrow things down. Do you know where this beetle was photographed? Googlemeister (talk) 20:35, 12 October 2011 (UTC)[reply]

"This is an unknown beetle photo taken in Fort Mill, South Carolina."" from the image description Sfan00 IMG (talk) 20:42, 12 October 2011 (UTC)[reply]

Most likely Cotinis nitida, which is common and easily found in the area. SemanticMantis (talk) 21:02, 12 October 2011 (UTC)[reply]

I added "beetle" to the title to distinguish from your other "Species identification" questions. StuRat (talk) 14:53, 13 October 2011 (UTC) [reply]