Wikipedia:Reference desk/Archives/Science/2013 March 31

= March 31 =

Best way to reproduce phone static sounds immediately before hanging up?
If I'm not in the right mood to rudely tell them to stop calling or something just as hurtful, but I need for them to end the call, I'd rather not sound offense or aggressive, so instead, I'd rather reproduce a sound that best mimics phone static immediately before hanging in order to make it sound like it was never my fault / own action. I hope your suggestions work well. Thanks. --70.179.161.230 (talk) 10:16, 31 March 2013 (UTC)


 * There's no need to be rude in these circumstances: simply say "Please take me off your list as I do not want to be called by you again. Thank you" and put the phone down. Or say "No thank you" and put the phone down. Or just put the phone down. Or if you have a mobile phone, you can get an app called Mr. Number that does this before you have a chance to answer. It's not being rude. They're the ones being rude by calling you when you don't want them to. If you're in the UK, register with the Telephone Preference Service, which cuts out most of the unwanted calls. --TammyMoet (talk) 11:05, 31 March 2013 (UTC)


 * Indeed, sales people are more than used to people saying "Thank you" and hanging up. It's not rude. If they think you just can't say no, then they'll probably call you again. OsmanRF34 (talk) 11:25, 31 March 2013 (UTC)


 * Unfortunately, the UK telephone preference service option is honoured only by reputable companies. Many of the disreputable ones who often withhold their number, or spoof it, or call from abroad, just ignore the option because they know that they are unlikely to be prosecuted.  I've had such telepests openly refuse to take my number off their list, and others just laugh at the idea that they can be fined up to half a million pounds.  It's time we had international legislation on this, but it is unlikely to happen because the phone companies make profit from such calls. (/rant)    D b f i r s   11:30, 31 March 2013 (UTC)


 * Agreed. I registered with the Australian equivalent, called the Do Not Call Register, and it only stopped sales calls from Australian companies.  The other 95% of pest calls kept on happening.  The DNC law is a complete waste.  So I did what most people have done - bought a digital answering machine.  Unless you leave a sensible voice message and have a valid reason, you don't get to talk to me.  Wickwack 58.169.233.136 (talk) 12:22, 31 March 2013 (UTC)


 * In the nicest way, may I just say that you are asking us to help you deceive the caller. Pretending you have a bad reception on your telephone line is not being honest with the caller. (who is possibly some poor person, hating what he/she is doing but unable to find better) As others have said a polite "No thank you" is polite and truthful. Put yourself in the caller's shoes would you prefer deceit or honesty. Richard Avery (talk) 14:07, 31 March 2013 (UTC)


 * Audible white noise is an incredibly improbable way for telephone signal integrity to degrade using 2013 technology. If the signal degrades, the call abruptly terminates, in what is known as a dropped call, which are most common for mobile telephones.  The most believable way to simulate technical failures is to abruptly hang up.  If you're going to do that, you can also simply inform the caller that you intend to hang up, so they don't try to reconnect.  Nimur (talk) 14:38, 31 March 2013 (UTC)


 * My own experience is what works well is if you interrupt the caller as soon as you work out it's a telesales call and say "I won't be interested" (they usual say, "okay, thank you" and hang up, but you can hang up without waiting). The caller appears to appreciate being freed without further ado after being made aware that they have little chance of success. OTOH, submitting my details to the South African DMA (Direct Marketing Association), whose members (a few reputable companies) presumably leave you alone traceably led to those details (my email address) being used for spam. — Quondum 14:55, 31 March 2013 (UTC)
 * That used to work, and still works with reputable companies. Trouble is, companies calling from 3rd world countries have adapted.  They now either start the call by saying that its not a sales call, or if you tell them up front you don't take sales calls, they'll say it's not a sales call.  Then they go right ahead and make their sales pitch, in some cases disguised as a survey or say you have been randomly selected for a free gift - which invariably turns out to require you credit card details for which there is some excuse.  Wickwack 121.215.51.168 (talk) 00:44, 1 April 2013 (UTC)


 * If you expect the caller to put you on their don not call list you have to say "can you put me on your do not call list, I will wait while you do it." Otherwise, as soon as you hang up their autodialer will likely blank your information and the next call will pop up on their screen. μηδείς (talk) 15:43, 31 March 2013 (UTC)


 * Is there a special list to prevent them from calling Mafia dons ? I bet the telemarketers will honor that one ! :-) StuRat (talk) 16:00, 31 March 2013 (UTC)


 * As mentioned above, it is rude to cold call someone, so you should not feel bad about hanging up on them. They are also trained not to give you time to say you're not interested, as a small portion of overly polite people will end up buying something just so they don't seem rude.  You can either just hang up or ask to be taken off their phone list.  Think of this as good practice for dealing with live salesmen, who can be even more aggressive.  You need to learn to be just as aggressive, to deal with them. StuRat (talk) 16:05, 31 March 2013 (UTC)


 * "We have a low pressure sales environment here, we simply put the customer into a sealed chamber and evacuate all the air until they agree to buy." :-) StuRat (talk) 16:05, 31 March 2013 (UTC)


 * My Dad will always tell them that he can't talk at the moment, but if they give him their name and home phone number, he will call them back around dinner time. I think he got that from some TV comedian. In all seriousness, if it's a one-off thing, just hanging up is the best course. But if you, like me, start receiving calls from the same company on a regular basis, it is worth actually going through the motions to determine exactly who the company is, and then (if in the U.S)once you verbally notify them that you do not want to receive calls (make sure to write down the day time and who you talked to) you can start filing complaints through the FCC . Sure, it takes some work (you need to keep a good record of the date/time of calls), but it's surprisingly satisfying, and will get results. Ditch &#8733;  16:06, 31 March 2013 (UTC)


 * Yes, that joke was used on Seinfeld. Matt Deres (talk) 20:08, 31 March 2013 (UTC)


 * Own OR (actually experience): bothering is not worth your time. A 'thank you' + hanging is just a couple of seconds and the call center is probably from a pretty poor country (even if they speak in clear American English) far, far away, like the Philippines. They don't care about legal procedures nor about people who knows how to say no, these won't buy anything. OsmanRF34 (talk) 17:13, 31 March 2013 (UTC)
 * I think you were responding to another's thread, but I wanted to comment on your comment about "not bothering" with my own experience. I agree when it's a straight solicitation call then hanging up is best, but what I get a lot are pre-recorded messages that start-up when I answer. They generate from different numbers. There is no "dial 0" for an operator option, so you have to call them back to issue a "do not call" notice, and that often does not work. So in those cases, it's either 1. live with it 2. don't answer (In my case, being on call through work, this is not an option usually), or 3. change my number. None of those options being satisfactory, it takes some work to get the calls to stop. Also, just an aside, spam faxes are the worst, because they use up expensive toner, and even though they are supposed to have an "opt out" number to call, it often doesn't work. You have to get really creative.  Does anyone remember black-out faxes?  Ditch &#8733;  17:53, 31 March 2013 (UTC)

Previous responses.  Sean.hoyland  - talk 17:08, 31 March 2013 (UTC)


 * Maybe it's just me, but I got the impression that users posting from Manhattan, Kansas, are slightly weird and repetitive. OsmanRF34 (talk) 17:13, 31 March 2013 (UTC)


 * If you're in the United States, this is the short, short version: https://www.donotcall.gov/


 * Now, it's no guarantee you won't get calls. Businesses which do call, and do not take you off the list when asked, can be prosecuted (though I'm not sure if it's worth your time). You do have to renew every few years, and public services are exempt. &mdash;  The Hand That Feeds You :Bite 23:15, 31 March 2013 (UTC)
 * As has already been posted here, it is certainly a waste of time to register. Most calls come from third world countries and they are simple out of reach of prosecution.  Most calls these days are from companies for whom the word "ethical" does not exist.  The following types of call to landlines are very common these days, and collectively far outnumber genuine calls from reputable companies:-
 * Calls claiming to be surveys that turn out to be sales calls
 * Calls claiming to be surveys that are an attempt to trick you into revealing a credit card number
 * Calls claiming to award free gifts that require a purchase
 * Calls claiming to award free gifts that are an attempt to trick you into revealing a credit card number.
 * Calls claiming to be conducting a survey that are seeking personal information to be used in identify theft.
 * Calls that start off "Hi Mr Wickwack, this is Jake from Windows. We can see error messages coming from your computer, and wish to guide you through correcting the problem."  These guys seek to get you to install a key-logger or hard disk scanner program, so they can skim off personal details and credit card numbers.
 * All these ratbags are stopped by installing a digital answering machine, which these days are built into many phones and cost very little. The State Govt here has been running adverts on oldies radio stations and elsewhere warning about all these types, but estimate that folk are collectively loosing millions of dollars per year!  Wickwack 121.215.51.168 (talk) 01:03, 1 April 2013 (UTC)


 * Re-reading the Q, you may not be dealing with telemarketers, but just a friend or relative who doesn't know when to hang up. In that case, I suggest saying something like "Sorry, I've got to run !" rather than faking a disconnect.  If they figure out you're faking it, they could be hurt. StuRat (talk) 17:46, 1 April 2013 (UTC)
 * First of all, the failure modes I ran into were (1)sudden termination without any advence warning, and (2) on-off audio (some packets got lost while others did make it) which usually got better and rarely resulted in a hang. Never static.
 * If you don't want to talk to the caller right now, being honest seems to be the best way to do it... Tell them that you cannot keep talking. You may want to euphemise the reason a bit ;)
 * OTOH, if you don't want to talk to them at all, just hang up on them.
 * Telemarketers are paid on a per-sale basis. Don't let them get away too fast, make them waste their time. If they annoy you, tell them that you have to take another call (or my favorite, that you'll take the call from that other phone) but just put them on hold, with some "nice" music (like Amy Winehouse, everybody seemed to hate her guts even while she was ali... er, breathing). They call again? No prob, give them the same music. If everybody (or only all HD:Sci readers) uses the same song (say, Rehab), they'll soon hear that song in their nightmares. Mission accomplished.
 * Plan B: Give them some white noise, at full blast. If they don't use safe-for-work headsets, that'll give them a good headache. And since they are on a "get rich quick" scheme, you can bet your bottom dollar their headsets will suck. (Only do that one if cold calls are illegal, thus your "reply" counts as self-defense.)
 * No number / foreign number: redirect all of those to the answering machine. Once per week, "You have X new messages" *push* "*blip* No new messages". - ¡Ouch! (hurt me / more pain) 11:24, 2 April 2013 (UTC)
 * There's no need for static noises, as long as you hang up whilst you are in mid-sentence. William Avery (talk) 22:19, 3 April 2013 (UTC)


 * did anybody say blow into the mouthpiece ? It's consistent and you just pretend that you can't hear them, like keep saying hello? In between breaths.68.36.148.100 (talk) 02:18, 5 April 2013 (UTC)

Rape and appearance
Is there any scientifically studied correlation to how the victims look like (and maybe how they dress) and being a victim of rape? OsmanRF34 (talk) 16:18, 31 March 2013 (UTC)


 * Perhaps not a direct study, but some individual factor pairs correlate well. This suggests that the sum of factors may also correlate. One such correlation, would be: the dress of a person v.s their relative sexual appeal. Another correlation 'could' be: relative sexual appeal v.s. a person's favour with a sexual predator. It would not be an illogical extention to link the two correlaions, perhaps not politically correct, but indeed a scientifically sound hypothesis. Plasmic Physics (talk) 20:38, 31 March 2013 (UTC)


 * We have an article on this topic: Victim blaming. --Guy Macon (talk) 20:50, 31 March 2013 (UTC)


 * This hypothesis isn't blaming the victim, the event is still determined by the volition of the offender, what is being suggested, is that the choice of dress may motivate the offender.


 * Old women get raped too, just as do passed-out drunken teenagers. The common thread across these types of cases is most likely to be vulnerability. As with most any crime, the criminal is aiming for the easiest target. ←Baseball Bugs What's up, Doc? carrots→ 21:15, 31 March 2013 (UTC)


 * True. Note that neither Osman, nor I implied that dress is the only factor, just that it is a factor. Plasmic Physics (talk) 21:45, 31 March 2013 (UTC)


 * Note: I didn't imply that it is a factor. I asked whether it is a factor. OsmanRF34 (talk) 22:49, 31 March 2013 (UTC)


 * Then you, Plasmic Physics, need to provide links to such studies instead of just guessing about what "could" be. Interesting that I can find nothing in the article Rape about the victims' dress or appearance being a factor. Bielle (talk) 21:59, 31 March 2013 (UTC)


 * Interesting that the OP specifically asked for scientific references, while everyone here has been offering speculation. I've tried googling for references, and not surprisingly, most of the links repeat the logical fallacies, strawmen, and loose thinking exhibited above.  There are many websites that say something like "it's a myth that rape is done for sexual reasons instead of power & control", but none of them reference a single paper or offer a single shred of scientific evidence.  I haven't managed to find a single statistical study that says "the null hypothesis that appearance is not correlated with rape incidence is rejected/not rejected at alpha=0.05".  The closest I've come is A Natural History of Rape:
 * "One contributor, Michael Kimmel, criticizes Thornhill and Palmer's argument that female rape victims tend to be sexually attractive young women, rather than children or older women, contrary to what would be expected if rapists selected victims based on inability to resist. Kimmel argues that younger women are the least likely to be married and the most likely to be out on dates with men, and therefore are the most likely to be raped because of opportunity arising from social exposure and marital status."
 * This implies that it sexually attractive young women are definitely more likely to be raped. Kimmel disagrees with Thornhill & Palmer about why this is, but doesn't disagree with the statistic itself.  --140.180.254.209 (talk) 22:27, 31 March 2013 (UTC)


 * According to our article on the book, "Thornhill and Palmer's definition of rape as the coerced vaginal penetration of women of reproductive age." is very limiting. (Does it say anything about "attractive", however one might define the term?) It would, of course, give a strong bias to their study as they omit older women, men and children. It is not a valid study of rape, then, but of rape of just a specific sector of the population. Drawing general conclusions from it would be unsupportable. Bielle (talk) 22:41, 31 March 2013 (UTC)
 * Read my post more carefully. Clearly they're not excluding children or older women, because they specifically mentioned those groups.  --140.180.254.209 (talk) 22:45, 31 March 2013 (UTC)
 * Yes which highlights a point that they seem to be contradicting themselves. Issues with their definition are noted in our article
 * Hamilton (2008) has criticized Thornhill and Palmer's definition of rape as the coerced vaginal penetration of women of reproductive age. He has suggested that the exclusion of male rape, rape on women outside the reproductive age range, murderous rape, and non-vaginal forms of rape virtually guaranteed the confirmation of their hypothesis that rape is an evolved reproductive strategy and not a crime of violence
 * Perhaps they explain in the book how they can make comments on the statistics of older women and children if their definition excludes them but nothing presented here explains that. Perhaps when they say older women they mean 35-45 years old who would normally be considered to still be in reproductive age and children they mean post-pubescent teenagers (e.g. 13-16). There are of course other problems with including children or even post-pubescent teenagers that they would have to consider in any analysis of statistics.
 * Nil Einne (talk) 23:00, 31 March 2013 (UTC)
 * BTW our article also notes:
 * He (Psychology professor Frans de Waal) questions why one-third of rape victims are young children and the elderly, too young or too old to reproduce, if rape is about reproduction and why most men do not rape if rape is a smart reproductive strategy.
 * Presuming this author's definition is something less controversial, it gives some idea on the statistics we're talking about. It does imply that young adult women are more likely to be raped if we accept these statistics (and for any statistics it seems that's a big 'if' since ignoring the definition controversy, there's also the question on how reliable the statistics are due to reporting difference which is probably biased in a variety of manners), since I'm reasonably sure the percentage of population of women in these groups is larger then 1/3. The difference in statistics however sounds to be small enough that it's easy that 'why' has many possible answers even if we accept them as accurate.
 * P.S. I'm aware the earlier quote is someone else commenting on the book and apparently agreeing with the statistics just not the reasoning, the trouble there is since what's quote in our article seems to be discussing the argument, it's unclear what definition they're using.
 * Nil Einne (talk) 23:42, 31 March 2013 (UTC)
 * That criticism makes absolutely no sense. If 1/3 of rape victims are unable to reproduce, it follows that 2/3 of rape victims are able to reproduce, and so rape might be a smart reproductive strategy for some men.  I also don't understand why "a crime of violence" cannot also be "an evolved reproductive strategy"; it's not as if the two are mutually exclusive.  In any case, we can debate the book endlessly, but nobody else has provided anything resembling a scientific reference that addresses the OP's question.  --140.180.254.209 (talk) 06:51, 1 April 2013 (UTC)

give complete description of law of symmetry in solid state
Titunsam (talk) 18:07, 31 March 2013 (UTC)


 * This has the look of a homework problem, which we don't do. On the other hand, homework problems usually make sense, and this doesn't. Looie496 (talk) 19:43, 31 March 2013 (UTC)
 * I would guess Crystallography is the appropriate article to direct them to. Dmcq (talk) 20:16, 31 March 2013 (UTC)
 * My first thought would be Molecular_symmetry, but it's hard to tell exactly what this question is asking. (+)H3N-Protein\Chemist-CO2(-) 13:23, 1 April 2013 (UTC)

What is the lettering on centimetre cubes in meteorite photography?
Pictures of meteorites commonly include one centimetre cubes to provide scale for the viewer. The cubes are marked with a letter on each face, and the letters used are T, B, N, S, E, and W. Why are those letters used, what do they mean, and is there a technical name used by geologists or photographers for these cubes? For what it's worth, I notice that N, S, E, and W correspond to the four cardinal points of the compass, and T and B could mean top and bottom, but these are merely my unconfirmed speculations. A link in your answer to an online discussion of these cubes would be appreciated. I have had only partial success in my own searching. Thank you. — O'Dea (talk) 20:41, 31 March 2013 (UTC)


 * Here is where I buy mine: http://scaleobjects.com/scale%20cubes/scalecubes.html They have some info on their web site. --Guy Macon (talk) 20:58, 31 March 2013 (UTC)


 * Thank you, Guy. I have only seen these cubes in studio or laboratory photography and I wonder if the N, S, E, and W faces are intentionally used in those settings to indicate the original lie of the rock found in nature, or are the letters ignored in the studio, and the cube merely used to indicate scale? And are the compass point letters used consciously in the field to record alignment, in situ? Any pictures that I have seen of rocks in the field have used rock hammers or rulers to provide scale. — O'Dea  (talk) 21:11, 31 March 2013 (UTC)

Scale cubes were first used at the Lunar Receiving Laboratory. With lunar samples, it is important to keep track of what the orientation was on the moon -- the different sides usually have different amounts of micrometeorite erosion. The scientists would determine the original orientation by looking at the pictures of the sample on the lunar surface and using time and shadows to calculate the orientation, often using a Gnomon. Later, on earth, some samples were cut open, split into pieces, photographed bottom-side-up, etc. The scale cube was used to show scale and keep track of orientation no matter what got done to the sample.

Sometimes it can be difficult to tell orientation in engineering failure-analysis photographs. A pneumatic piston, for example, usually has rotational symmetry. if you want to show some damage on opposite sides, it can be difficult to tell from the photo if the marks are 180 degrees from each other or some other angle, and if it is undamaged you often end up with photos taken from different angles that look pretty much identical. Using a scale cube and rotating it to match the piston leaves no doubt. It also makes it really obvious when you accidentally mirror-image the photo. --Guy Macon (talk) 05:36, 1 April 2013 (UTC)

Calcium supplements
Two brands of calcium supplements both say on the label: "Take a few hours before or after taking other medications." No reason is given but I think it is so the calcium product does not interfere with the other medications.

I wondered how long after taking calcium it was "necessary" to wait before taking other medications so I did an experiment. I put a calcium pill in a glass of ordinary white vinegar. The results were surprising to me.

Type A pill which is labelled as "calcium carbonate providing elemental calcium" was disintegrated and largely dissolved after 20 minutes. The undissolved material was white and powdery.

Type B pill which is labelled as "elemental calcium from a complex of carbonate, citrate, fumarate, malate, succinate" was very slow to disintegrate and dissolve. After three days it was less broken down than type A was after 20 minutes.

Questions: 1) Does my "put it in vinegar" test represent in any useful way what would happen to the pill when swallowed? I.e., is type A likely to dissolve roughly 200 times faster when swallowed than type B?

2) Would the time to wait after taking type B and before taking other medications be of the order of days rather than hours because it lingers so long? Or is it a matter of allowing time for the calcium to leave the stomach and get into the intestines before taking other medication?

(Additional information which may complicate the whole thing. Both types also contain magnesium.  As with calcium, the chemical compounds are different.  Type A says oxide & carbonate; type B says oxide, citrate, fumarate, malate, succinate.  And type B has a much higher ratio of magnesium to calcium, six times as much according to the label.)

Thanks, CBHA (talk) 21:31, 31 March 2013 (UTC)


 * The problem with your interesting analysis is that you don't know what you are looking at. The white powdery material that you saw with pill B might be inert filler, and may have no relevance to the rate of dissolution and absorption of the calcium itself.  No, they aren't telling you to wait for days before taking other pills.  Agricolae (talk) 21:43, 31 March 2013 (UTC)


 * I disagree. The binder has to disintegrate before the calcium can be absorbed, so the one with the binder which dissolves more quickly should presumably also be absorbed more quickly.  However, stomach acid is mostly hydrochloric acid (also called muriatic acid), so you might want to get some of that from a hardware store to do a better test. StuRat (talk) 05:20, 1 April 2013 (UTC)


 * An antibiotic was labled do not drink milk with it. So this might be the case if the calcium and the drug form a stable complex slowing down the transfer into the body.--Stone (talk) 08:56, 1 April 2013 (UTC)


 * I've also heard that chocolate should not be eaten with milk, as it deactivates the anti-oxidants found in chocolate. So much for milk chocolate, chocolate milk, chocolate ice cream, chocolate mousse and cocoa with whipped cream. StuRat (talk) 17:19, 1 April 2013 (UTC)


 * Also note that calcium should be taken with vitamin D, to increase it's rate of absorption. StuRat (talk) 17:15, 1 April 2013 (UTC)

According to the Dietary Supplements section on this NIH web page, calcium carbonate must be digested before absorption, whereas calcium citrate can be absorbed directly. Calcium carbonate reacts with acid in the stomach to release the calcium (and carbon dioxide). Vinegar is an acid that "digests" the calcium carbonate, leaving the binder/filler behind (starch?), but probably doesn't react with the other compounds much (citrate, etc.). If the calcium is absorbed in the intestine (is this true?) the calcium carbonate will have already been digested in the stomach, so the amount of time it takes to digest the CaCO3 wouldn't be a factor for speed of absorption. Our article on calcium has a section on dietary calcium supplements that mentions other calcium compounds as well.--Wikimedes (talk) 18:42, 1 April 2013 (UTC)